Systemic Absorption of Catechins after Intraruminal or Intraduodenal Application of a Green Tea Extract in Cows

PubMed Central

Wein, Silvia; Beyer, Birgit; Gohlke, Annika; Blank, Ralf; Metges, Cornelia C.; Wolffram, Siegfried

2016-01-01

Green tea catechins have various potential health benefits in humans including anti-inflammatory, anti-oxidative and hepato-protective effects. If present in the circulation, they might have similar effects in ruminants, which are exposed to oxidative stress and fatty liver disease such as dairy cows during the periparturient phase. However, the bioavailability of a substance is a prerequisite for any post absorptive effect in vivo. This study aimed to investigate the appearance of catechins from a green tea extract (GTE) in cattle plasma after intraruminal and intraduodenal administration because absorption is of major importance regarding the bioavailability of catechins. The studies were performed in 5 rumen-fistulated non-lactating heifers and 6 duodenally fistulated lactating dairy cows, respectively, equipped with indwelling catheters placed in a jugular vein. The GTE was applied intraruminally (10 and 50 mg/kg BW, heifers) or duodenally (10, 20 and 30 mg/kg BW, dairy cows) in a cross‐over design with a 2 d washout period between different dosages. Blood samples were drawn following the GTE administration at various pre-defined time intervals. The concentration of the major GTE catechins (gallocatechin, epigallocatechin, catechin, epicatechin, epigallocatechin-gallate, epicatechin-gallate) in plasma samples were analysed by HPLC with electrochemical detection. Irrespective of the dose, almost none of the catechins originally contained in the GTE were detected in plasma samples after intraruminal application. In contrast, intraduodenal administration of GTE resulted in increased plasma concentrations of epicatechin, epigallocatechin, epigallocatechin gallate in a dose‐dependent manner. Thus, we can conclude that intraruminally or orally administered catechins are intensively metabolized by ruminal microorganisms. PMID:27427946

Application of α-aminoisobutyric acid and β-aminoisobutyric acid inhibits pericarp browning of harvested longan fruit.

PubMed

Wang, Hui; Zhi, Wei; Qu, Hongxia; Lin, Hetong; Jiang, Yueming

2015-12-01

Pericarp browning is a critical problem resulting in reduced commercial value and shelf life of longan fruit. Two non-protein amino acids, α-aminoisobutyric acid (AIB) and β-aminoisobutyric acid (BAIB) at 100 and 1 mM were applied to longan fruit prior to storage for up to 8 days at 25 °C respectively. Contents of the major five phenolics (gallic acid, catechin, corilagin, epicatechin and gallocatechin gallate) were assayed by high-performance liquid chromatography (HPLC). Physiological properties related to pericarp browning of longan fruit were investigated during storage. Respiration rate, membrane permeability, malondialdehyde (MDA) content, and activities of polyphenol oxidase (PPO) and peroxidase (POD) were down-regulated by AIB or BAIB treatments, with significantly lower pericarp browning index and higher proportion of edible fruit than the control. Moreover, exogenous application of AIB and BAIB maintained higher contents of catechin, corilagin, epicatechin and gallocatechin gallate, but lower content of gallic acid compared to the control in the pericarp of longan fruit during storage, which was associated with the oxidation of browning substrate. Pericarp browning was inhibited and storage life of longan fruit was extended effectively by AIB and BAIB treatments with AIB treatment being more significant than BAIB. The findings may provide a new strategy for controlling pericarp browning of harvested longan fruit.

Polymeric proanthocyanidins from the bark of Hamamelis virginiana.

PubMed

Dauer, A; Rimpler, H; Hensel, A

2003-01-01

Polymeric proanthocyanidins were isolated from the bark of Hamamelis virginiana L. in yields of about 5 %. Fractionation yielded fractions with similar structures but different molecular weights with DP between 17-29 (thiolysis) and 11-20 (GPC). Polymers were composed predominantly of epicatechin and epigallocatechin as chain extension units at ratio of about 1.3:1. Terminal chain units were catechin (approximately 95 %) and gallocatechin (approximately 5 %). All chain extension units were completely galloylated at position O-3, while chain terminating units were not galloylated. Predominant interflavan linkages were 4 --> 8-bonds.

Direct scavenging of nitric oxide and superoxide by green tea.

PubMed

Nakagawa, T; Yokozawa, T

2002-12-01

In the present study, we investigated the free radical scavenging effects of green tea extract and green tea tannin mixture and its components using a nitric oxide (NO) and superoxide (O(2)(-)) generating system in vitro. Green tea extract showed direct scavenging activity against NO and O(2)(-) and green tea tannin mixture, at the same concentration, showed high scavenging activity. Comparison of the activities of seven pure compounds isolated from green tea tannin mixture showed that (-)-epigallocatechin 3-O-gallate (EGCg), (-)-gallocatechin 3-O-gallate (GCg) and (-)-epicatechin 3-O-gallate (ECg) had higher scavenging activities than (-)-epigallocatechin (EGC), (+)-gallocatechin (GC), (-)-epicatechin (EC) and (+)-catechin (C), showing the importance of the structure of flavan-3-ol linked to gallic acid for this activity. Among the gallate-free tannins, EGC and GC were more effective O(2)(-) scavengers than EC and C, indicating the O-trihydroxy structure in the B ring is an important determinant of such activity. However, this structure did not affect the NO scavenging activity. These findings confirm that green tea tannin has excellent antioxidant properties, which may be involved in the beneficial effect of this compound.

Validation of AN Hplc-Dad Method for the Classification of Green Teas

NASA Astrophysics Data System (ADS)

Yu, Jingbo; Ye, Nengsheng; Gu, Xuexin; Liu, Ni

A reversed phase high performance liquid chromatography (RP-HPLC) separation coupled with diode array detection (DAD) and electrospray ionization mass spectrometer (ESI/MS) was developed and optimized for the classification of green teas. Five catechins [epigallocatechin (EGC), epigallocatechin gallate (EGCG), epicatechin (EC), gallocatechin gallate (GCG), epicatechin gallate (ECG)] had been identified and quantified by the HPLC-DAD-ESI/MS/MS method. The limit of detection (LOD) of five catechins was within the range of 1.25-15 ng. All the analytes exhibited good linearity up to 2500 ng. These compounds were considered as chemical descriptors to define groups of green teas. Chemometric methods including principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied for the purpose. Twelve green tea samples originating from different regions were subjected to reveal the natural groups. The results showed that the analyzed green teas were differentiated mainly by provenance; HCA afforded an excellent performance in terms of recognition and prediction abilities. This method was accurate and reproducible, providing a potential approach for authentication of green teas.

Recent Advances in the Chemistry of Condensed Tannins

Treesearch

Richard W. Hemingway; Gerald W. McGraw; J.J. Karchesy; L.Y. Foo; L.J. Porter

1983-01-01

The presence of the procyanidins epicatechin-(4β-8)-catechin, epicatechin-{4β-6)-catechin, catechin-(4α-8)-catechin, epicatechin-(4β-8)-epicatechin-(4β-8)-catechin, epicatechin-(4β-6)-epicatechin-(4β-8)-catechin, and epicatechin-(4β-8)-epicatechin-(4β-6)catechin in tile phloem of ...

Potential anthelmintics: polyphenols from the tea plant Camellia sinensis L. are lethally toxic to Caenorhabditis elegans.

PubMed

Mukai, Daisuke; Matsuda, Noriko; Yoshioka, Yu; Sato, Masashi; Yamasaki, Toru

2008-04-01

A novel gallate of tannin, (-)-epigallocatechin-(2 beta-->O-->7',4 beta-->8')-epicatechin-3'-O-gallate (8), together with (-)-epicatechin-3-O-gallate (4), (-)-epigallocatechin (5), (-)-epigallocatechin-3-O-gallate (6), and (+)-gallocatechin-(4 alpha-->8')-epigallocatechin (7), were isolated from the tea plant Camellia sinensis (L.) O. Kuntze var. sinensis (cv., Yabukita). The structure of 8, including stereochemistry, was elucidated by spectroscopic methods and hydrolysis. The compounds, along with commercially available pyrogallol (1), (+)-catechin (2), and (-)-epicatechin (3), were examined for toxicity towards egg-bearing adults of Caenorhabditis elegans. The anthelmintic mebendazole (9) was used as a positive control. Neither 2 nor 3 were toxic but the other compounds were toxic in the descending order 8, 7 approximately 6, 9, 4, 5, 1. The LC(50) (96 h) values of 8 and 9 were evaluated as 49 and 334 micromol L(-1), respectively. These data show that many green tea polyphenols may be potential anthelmintics.

Quantitative analysis of major constituents in green tea with different plucking periods and their antioxidant activity.

PubMed

Lee, Lan-Sook; Kim, Sang-Hee; Kim, Young-Boong; Kim, Young-Chan

2014-07-01

The objective of this study was to determine the relationship between the plucking periods and the major constituents and the antioxidant activity in green tea. Green tea was prepared from leaves plucked from the end of April 2013 to the end of May 2013 at intervals of one week or longer. The contents of theanine, theobromine, caffeine, catechin (C), and gallocatechin gallate (GCg) were significantly decreased, whereas those of epicatechin (EC), epigallocatechin gallate (EGCg) and epigallocatechin (EGC) were significantly increased along with the period of tea leaf plucking. In addition, antioxidant activity of green tea and standard catechins was investigated using ABTS, FRAP and DPPH assays. The highest antioxidant activity was observed in relatively the oldest leaf, regardless of the assay methods used. Additionally, the order of antioxidant activity of standard catechins was as follows: EGCg≥GCg≥ECg>EGC≥GC≥EC≥C. Moreover, the cis-catechins contents were the key factor affecting the antioxidant activity of green tea in all assays employed (ABTS, r=0.731, p<0.01; FRAP, r=0.886, p<0.01; DPPH, r=0.778, p<0.01).

Preparative isolation and purification of theaflavins and catechins by high-speed countercurrent chromatography.

PubMed

Wang, Kunbo; Liu, Zhonghua; Huang, Jian-an; Dong, Xinrong; Song, Lubing; Pan, Yu; liu, Fang

2008-05-15

High-speed countercurrent chromatography (HSCCC) has been applied for the separation of theaflavins and catechins. The HSCCC run was carried out with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water-acetic acid (1:5:1:5:0.25, v/v) by eluting the lower aqueous phase at 2 ml/min at 700 rpm. The results indicated that pure theaflavin, theaflavins-3-gallate, theaflavins-3'-gallate and theaflavin-3,3'-digallate could be obtained from crude theaflavins sample and black tea. The structures of the isolated compounds were positively confirmed by (1)H NMR and (13)C NMR, MS analysis, HPLC data and TLC data. Meanwhile, catechins including epigallocatechin gallate, gallocatechin gallate, epicatechin gallate and epigallocatechin were isolated from the aqueous extract of green tea by using the same solvent system. This study developed a modified method combined with enrichment theaflavins method by using HSCCC for separation of four individual theaflavins, especially for better separation of theaflavins monogallates.

Inhibitory effect of six green tea catechins and caffeine on the growth of four selected human tumor cell lines.

PubMed

Valcic, S; Timmermann, B N; Alberts, D S; Wächter, G A; Krutzsch, M; Wymer, J; Guillén, J M

1996-06-01

Green tea is an aqueous infusion of dried unfermented leaves of Camellia sinensis (family Theaceae) from which numerous biological activities have been reported including antimutagenic, antibacterial, hypocholesterolemic, antioxidant, antitumor and cancer preventive activities. From the aqueous-alcoholic extract of green tea leaves, six compounds (+)-gallocatechin (GC), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG) and caffeine, were isolated and purified. Together with (+)-catechin, these compounds were tested against each of four human tumor cells lines (MCF-7 breast carcinoma, HT-29 colon carcinoma, A-427 lung carcinoma and UACC-375 melanoma). The three most potent green tea components against all four tumor cell lines were EGCG, GC and EGC. EGCG was the most potent of the seven green tea components against three out of the four cell lines (i.e. MCF-7 breast cancer, HT-29 colon cancer and UACC-375 melanoma). On the basis of these extensive in vitro studies, it would be of considerable interest to evaluate all three of these components in comparative preclinical in vivo animal tumor model systems before final decisions are made concerning which of these potential chemopreventive drugs should be taken into broad clinical trials.

A History of Catechin Chemistry with Special Reference to Tea Leaves

NASA Astrophysics Data System (ADS)

Ryoyasu, Saijo; Katoh, Miyuki

This review describes the history of the discovery of catechins, i.e., flavan 3-ols in the flavonoid compounds, with a special reference to tea leaves. 1. Catechin was first separated from gambier catechu and acacia catechu, and its molecular weight and chemical structure were proposed in 1902. By 1948 the six catechins,(+)-catechin,(-)-epicatechin,(-)-epicatechin 3-O-gallate,(-)-epigallocatechin,(+)-gallocatechin, and(-)-epigallocatechin 3-O-gallate, as shown in Table 1, had been found in a variety of plants, including tea. Table 1 summarizes each catechin, the plant associated with it, and the year and authorship of each first reporting.(-)-Epigallocatechin 3-gallate was isolated from tea leaves in 1948 as the last compound of the six catechins, even though it accounted for the largest proportion of total catechin content. The compound was not isolated and purified by traditional separation methods, such as the ethyl acetate extraction and lead acetate precipitation methods; instead, silica gel column chromatography was the key technique used to succeed in the separation and purification of the compound, from which the determination of the chemical structure followed. 2. The six catechins in fresh tea leaves are easily epimerized by heat treatment to form the corresponding epimerized catechins, as shown in Table 2. Observation indicates that the six natural and six epimerized catechins can be present in heat-treated dried tea leaves or green teas. 3. The chemical structures of the ten catechins, which include the compounds in Table 1, are shown in Table 3. As the contents of the catechins in fresh tea leaves have been reported many times in the literature, it is certain that these compounds are naturally present in tea leaves. 4. Table 4 summarizes the chemical structures of eight minor catechin derivatives found in tea leaves and oolong teas, the first reporting authors, and the year reported. Because the presence of these catechin derivatives in fresh tea leaves has not been strictly determined, it has not yet been made clear whether the compounds are naturally occurring ones. It is possible that some of these compounds might be artifacts. 5. Table 5 summarizes the chemical structures of eight afzelechin derivatives, the first reporting authors, and the year reported. 6. Table 6 summarizes the chemical structures of ten(+)-catechin derivatives, the first reporting authors, and the year reported.

Antioxidative activity of green tea treated with radical initiator 2, 2'-azobis(2-amidinopropane) dihydrochloride.

PubMed

Yokozawa, T; Cho, E J; Hara, Y; Kitani, K

2000-10-01

This study investigated the antioxidative activity of green tea extract, and a green tea tannin mixture and its components, under conditions of radical generation using the hydrophilic azo compound, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) to generate peroxyl radicals at a constant and measurable rate in the cultured renal epithelial cell line, LLC-PK(1), which is susceptible to oxidative damage. Treatment with AAPH decreased cell viability and increased the formation of thiobarbituric acid-reactive substances. However, green tea extract, and the tannin mixture and its components, comprising (-)-epigallocatechin 3-O-gallate (EGCg), (-)-gallocatechin 3-O-gallate (GCg), (-)-epicatechin 3-O-gallate (ECg), (-)-epigallocatechin (EGC), (+)-gallocatechin (GC), (-)-epicatechin (EC), and (+)-catechin (C), showed protective activity against AAPH-induced cellular damage. The tannin mixture and its components exhibited higher antioxidative activity than the green tea extract. Furthermore, EGCg and GCg had higher activity than EGC and GC, respectively. In particular, EGCg exerted the most significant cellular protective activity against AAPH. These results indicate that green tea tannin may inhibit cellular loss and lipid peroxidation resulting from the peroxyl radical generated by AAPH, and that the chemical structure of tannin is also involved in the activity, suggesting that the O-dihydroxy structure in the B ring and the galloyl groups are important determinants for radical scavenging and antioxidative potential.

Catechins and procyanidins of Ginkgo biloba show potent activities towards the inhibition of β-amyloid peptide aggregation and destabilization of preformed fibrils.

PubMed

Xie, Haiyan; Wang, Jing-Rong; Yau, Lee-Fong; Liu, Yong; Liu, Liang; Han, Quan-Bin; Zhao, Zhongzhen; Jiang, Zhi-Hong

2014-04-22

Catechins and procyanidins, together with flavonoid glycosides and terpene trilactones, are three important categories of components in the standard extract of Ginkgo biloba leaves (EGb761). In this research, catechins and proanthocyanidins were found to exist in both the extract of Ginkgo leaves and Ginkgo products. By comparing with reference compounds, six of them were identified as (+)-catechin, (-)-epicatechin, (-)-gallocatechin, (-)-epigallocatechin and procyanidins B1 and B3. The activities of these polyphenols in the inhibition of Aβ42 aggregation and the destabilization of preformed fibrils were evaluated using biochemical assays, which showed that all six of the polyphenols, as well as a fraction of the extract of Ginkgo biloba leaves (EGb) containing catechins and procyanidins, exerted potent inhibitory activities towards Aβ42 aggregation and could also destabilize the performed fibrils. Catechins and procyanidins can therefore be regarded as the potent active constituents of EGb761 in terms of their inhibition of Aβ42 aggregation and destabilization of the fibrils. Although quantitative mass spectroscopic analysis revealed that the catechins and procyanidins are only present in low concentrations in EGb761, these components should be studied in greater detail because of their potent inhibitory effects towards Aβ42 aggregation and their ability to destabilize preformed fibrils, especially during the quality control of Ginkgo leaves and the manufacture of Ginkgo products.

Phenolic Profiles and Antioxidant Activity of Lotus Root Varieties.

PubMed

Yi, Yang; Sun, Jie; Xie, Jun; Min, Ting; Wang, Li-Mei; Wang, Hong-Xun

2016-06-30

Lotus root attracts increasing attention mainly because of its phenolic compounds known as natural antioxidants. Its thirteen varieties were systematically analyzed on the content, distribution, composition and antioxidant activity of phenolic compounds for a better understanding of this aquatic vegetable. The respective mean contents of total phenolics in their flesh, peel and nodes were 1.81, 4.30 and 7.35 mg gallic acid equivalents (GAE)/g fresh weight (FW), and those of total flavonoids were 3.35, 7.69 and 15.58 mg rutin equivalents/g FW. The phenolic composition determined by a high-performance liquid chromatography method varied significantly among varieties and parts. The phenolics of flesh were mainly composed of gallocatechin and catechin; those of peel and node were mainly composed of gallocatechin, gallic acid, catechin and epicatechin. The antioxidant activities of phenolic extracts in increasing order were flesh, peel and node; their mean concentrations for 50% inhibition of 2,2-diphenyl-1-picrylhydrazyl radical were 46.00, 26.43 and 21.72 µg GAE/mL, and their mean values representing ferric reducing antioxidant power were 75.91, 87.66 and 100.43 µg Trolox equivalents/100 µg GAE, respectively. "Zoumayang", "Baheou", "No. 5 elian" and "Guixi Fuou" were the hierarchically clustered varieties with relatively higher phenolic content and stronger antioxidant activity as compared with the others. Especially, their nodes and peels are promising sources of antioxidants for human nutrition.

Isolation and purification of condensed tannins from flamboyant tree and their antioxidant and antityrosinase activities.

PubMed

Feng, Hui-Ling; Tian, Ling; Chai, Wei-Ming; Chen, Xiao-Xin; Shi, Yan; Gao, Yu-Sen; Yan, Chong-Ling; Chen, Qing-Xi

2014-05-01

Flamboyant tree, a kind of medicinal plant, was studied as a source of condensed tannins. The antioxidant activities of the condensed tannins from the leaf, fruit, and stem bark of flamboyant tree were screened by ABTS radical and hydroxyl radical scavenging activity methods. The results indicated that these compounds possessed potent antioxidant activity. Their structures were then characterized by high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS) after thiolytic degradation. The results showed that the leaf condensed tannins were composed of afzelechin/epiafzelechin, catechin/epicatechin, and gallocatechin/epigallocatechin, while the fruit and stem bark condensed tannins had afzelechin/epiafzelechin and catechin/epicatechin. In addition, the condensed tannins were evaluated for their antityrosinase ability. They were found to have significant antityrosinase activity. The IC50 values were 35 ± 2.0 and 40 ± 0.5 μg/ml for the condensed tannins of fruit and stem bark, respectively. Further, fluorescence quenching and copper interacting techniques were utilized to unravel the molecular mechanisms of the inhibition. The results showed that the hydroxyl group of the condensed tannins could chelate the dicopper center of the enzyme and interact with tryptophan residues. Our studies revealed that condensed tannins might be suitable for use in food, agriculture, cosmetic, nutraceutical, and pharmaceutical applications.

Molecular Docking Studies of Catechin and Its Derivatives as Anti-bacterial Inhibitor for Glucosamine-6-Phosphate Synthase

NASA Astrophysics Data System (ADS)

Fikrika, H.; Ambarsari, L.; Sumaryada, T.

2016-01-01

Molecular docking simulation of catechin and its derivatives on Glucosamine-6- Phosphate Synthase (GlmS) has been performed in this research. GlmS inhibition by a particular ligand will suppress the production of bacterial cell wall and significantly reduce the population of invading bacteria. In this study, catechin derivatives i.e epicatechin, galloatechin and epigalloatechin were found to have stronger binding affinities as compared to natural ligand of GlmS, Fructose-6-Phosphate (F6P). Those three ligands were docked on the same pocket in GlmS target as F6P, with 70% binding sites similarity. Based on the docking results, gallocatechin turns out to be the most potent ligand for anti-bacterial agent with ΔG= -8.00 kcal/mol. The docking between GlmS and catechin derivatives are characterized by a constant present of a strong hydrogen bond between functional group O3 and Ser-349. This hydrogen bond most likely plays a significant role in the docking mechanism and binding modes selection. The surprising result is catechin itself exhibited a quite strong binding with GlmS (ΔG= -7.80 kcal.mol), but docked on a completely different pocket compared to other ligands. This results suggest that catechin might still have a curing effect but with a completely different pathway and mechanism as compared to its derivatives.

Proanthocyanidins in wild sea buckthorn (Hippophaë rhamnoides) berries analyzed by reversed-phase, normal-phase, and hydrophilic interaction liquid chromatography with UV and MS detection.

PubMed

Kallio, Heikki; Yang, Wei; Liu, Pengzhan; Yang, Baoru

2014-08-06

A rapid and sensitive method for profiling of proanthocyanidins (PAs) of sea buckthorn (Hippophaë rhamnoides) berries was established based on aqueous, acidified acetone extraction. The extract was purified by Sephadex column chromatography and analyzed using reversed-phase, normal-phase, and hydrophilic interaction liquid chromatography (HILIC). Negative ion electrospray ionization mass spectrometry (ESI-MS) in single ion recording (SIR) and full scan modes combined with UV detection were used to define the combinations and ratios of PA oligomer classes. PAs with degree of polymerization from 2 to 11 were detected by HILIC-ESI-MS. Quantification of dimeric, trimeric, and tetrameric PAs was carried out with ESI-MS-SIR, and their molar proportions were 40, 40, and 20%, respectively. Only B-type PAs were found, and (epi)gallocatechins were the main monomeric units. More than 60 combinations of (epi)catechins and (epi)gallocatechins of proanthocyanidin dimers and trimers were found. A majority of the PAs were shown to be higher polymers based on the HILIC-UV analysis.

Direct enantioseparation of catechin and epicatechin in tea drinks by 6-O-alpha-D-glucosyl-beta-cyclodextrin-modified micellar electrokinetic chromatography.

PubMed

Kodama, Shuji; Yamamoto, Atsushi; Matsunaga, Akinobu; Yanai, Hiroko

2004-08-01

Cyclodextrin-modified micellar electrokinetic chromatography was applied to the enantioseparation of catechin and epicatechin using 6-O-alpha-D-glucosyl-beta-cyclodextrin together with sodium dodecyl sulfate and borate-phosphate buffer. Factors affecting chiral resolution and migration time of catechin and epicatechin were studied. The optimum running conditions were found to be 200 mM borate-20 mM phosphate buffer (pH 6.4) containing 25 mM 6-O-alpha-D-glucosyl-beta-cyclodextrin and 240 mM sodium dodecyl sulfate with an effective voltage of +25 kV at 20 degrees C using direct detection at 210 nm. Under these conditions, the resolution (Rs) of racemic catechin and epicatechin were 4.15 and 1.92, respectively. With this system, catechin and epicatechin enantiomers along with other four catechins ((-)-catechin gallate, (-)-epicatechin gallate, (-)-epigallocatechin, (-)-epigallocatechin gallate) and caffeine in tea samples were analyzed successfully. The difference of migration time between catechin and epicatechin is discussed.

Variations in the heterogeneity of the decay of the fluorescence in six procyanidin dimers

Treesearch

Donghwan Cho; Rujiang Tian; Lawrence J. Porter; Richard W. Hemingway; Wayne L. Mattice

1990-01-01

The decay of the fluorescence has been measured in 1,4-dioxane for six dimers of (2R,3R)-(-)-epicatechin and (2R,3S)-(+)-catechin, hereafter denoted simply epicatechin and catechin. The dimers are epicatechin-(4β→8)-catechin, epicatechin-(4β→8)-epicatechin...

Impact of fermentation, drying, roasting and Dutch processing on flavan-3-ol stereochemistry in cacao beans and cocoa ingredients

PubMed Central

2011-01-01

This paper reports a systematic study of the level of flavan-3-ol monomers during typical processing steps as cacao beans are dried, fermented and roasted and the results of Dutch-processing. Methods have been used that resolve the stereoisomers of epicatechin and catechin. In beans harvested from unripe and ripe cacao pods, we find only (-)-epicatechin and (+)-catechin with (-)-epicatechin being by far the predominant isomer. When beans are fermented there is a large loss of both (-)-epicatechin and (+)-catechin, but also the formation of (-)-catechin. We hypothesize that the heat of fermentation may, in part, be responsible for the formation of this enantiomer. When beans are progressively roasted at conditions described as low, medium and high roast conditions, there is a progressive loss of (-)-epicatechin and (+)-catechin and an increase in (-)-catechin with the higher roast levels. When natural and Dutch-processed cacao powders are analyzed, there is progressive loss of both (-)-epicatechin and (+)-catechin with lesser losses of (-)-catechin. We thus observe that in even lightly Dutch-processed powder, the level of (-)-catechin exceeds the level of (-)-epicatechin. The results indicate that much of the increase in the level of (-)-catechin observed during various processing steps may be the result of heat-related epimerization from (-)-epicatechin. These results are discussed with reference to the reported preferred order of absorption of (-)-epicatechin > (+)-catechin > (-)-catechin. These results are also discussed with respect to the balance that must be struck between the beneficial impact of fermentation and roasting on chocolate flavor and the healthful benefits of chocolate and cocoa powder that result in part from the flavan-3-ol monomers. PMID:21917164

Impact of fermentation, drying, roasting and Dutch processing on flavan-3-ol stereochemistry in cacao beans and cocoa ingredients.

PubMed

Hurst, W Jeffrey; Krake, Susann H; Bergmeier, Stephen C; Payne, Mark J; Miller, Kenneth B; Stuart, David A

2011-09-14

This paper reports a systematic study of the level of flavan-3-ol monomers during typical processing steps as cacao beans are dried, fermented and roasted and the results of Dutch-processing. Methods have been used that resolve the stereoisomers of epicatechin and catechin. In beans harvested from unripe and ripe cacao pods, we find only (-)-epicatechin and (+)-catechin with (-)-epicatechin being by far the predominant isomer. When beans are fermented there is a large loss of both (-)-epicatechin and (+)-catechin, but also the formation of (-)-catechin. We hypothesize that the heat of fermentation may, in part, be responsible for the formation of this enantiomer. When beans are progressively roasted at conditions described as low, medium and high roast conditions, there is a progressive loss of (-)-epicatechin and (+)-catechin and an increase in (-)-catechin with the higher roast levels. When natural and Dutch-processed cacao powders are analyzed, there is progressive loss of both (-)-epicatechin and (+)-catechin with lesser losses of (-)-catechin. We thus observe that in even lightly Dutch-processed powder, the level of (-)-catechin exceeds the level of (-)-epicatechin. The results indicate that much of the increase in the level of (-)-catechin observed during various processing steps may be the result of heat-related epimerization from (-)-epicatechin. These results are discussed with reference to the reported preferred order of absorption of (-)-epicatechin > (+)-catechin > (-)-catechin. These results are also discussed with respect to the balance that must be struck between the beneficial impact of fermentation and roasting on chocolate flavor and the healthful benefits of chocolate and cocoa powder that result in part from the flavan-3-ol monomers.

Impact of fermentation, drying, roasting, and Dutch processing on epicatechin and catechin content of cacao beans and cocoa ingredients.

PubMed

Payne, Mark J; Hurst, W Jeffrey; Miller, Kenneth B; Rank, Craig; Stuart, David A

2010-10-13

Low molecular weight flavan-3-ols are thought to be responsible, in part, for the cardiovascular benefits associated with cocoa powder and dark chocolate. The levels of epicatechin and catechin were determined in raw and conventionally fermented cacao beans and during conventional processing, which included drying, roasting, and Dutch (alkali) processing. Unripe cacao beans had 29% higher levels of epicatechin and the same level of catechin compared to fully ripe beans. Drying had minimal effect on the epicatechin and catechin levels. Substantial decreases (>80%) in catechin and epicatechin levels were observed in fermented versus unfermented beans. When both Ivory Coast and Papua New Guinea beans were subjected to roasting under controlled conditions, there was a distinct loss of epicatechin when bean temperatures exceeded 70 °C. When cacao beans were roasted to 120 °C, the catechin level in beans increased by 696% in unfermented beans, by 650% in Ivory Coast beans, and by 640% in Papua New Guinea fermented beans compared to the same unroasted beans. These results suggest that roasting in excess of 70 °C generates significant amounts of (-)-catechin, probably due to epimerization of (-)-epicatechin. Compared to natural cocoa powders, Dutch processing caused a loss in both epicatechin (up to 98%) and catechin (up to 80%). The epicatechin/catechin ratio is proposed as a useful and sensitive indicator for the processing history of cacao beans.

Rapid reversed phase ultra-performance liquid chromatography analysis of the major cocoa polyphenols and inter-relationships of their concentrations in chocolate.

PubMed

Cooper, Karen A; Campos-Giménez, Esther; Jiménez Alvarez, Diego; Nagy, Kornél; Donovan, Jennifer L; Williamson, Gary

2007-04-18

Chocolate and other cocoa-containing products are a rich source of polyphenols. This paper describes an ultra-performance liquid chromatography (UPLC) method that can separate and quantify in 3 min six of the major chocolate polyphenols: catechin; epicatechin; B2 (epicatechin-4beta-8-epicatechin); B5 (epicatechin-4beta-6-epicatechin); C1 (epicatechin-4beta-8-epicatechin-4beta-8-epicatechin); and tetramer D (epicatechin-4beta-8-epicatechin-4beta-8-epicatechin-4beta-8-epicatechin). A survey of 68 chocolate samples indicated that there was a strongly predictive relationship between epicatechin and the other individual polyphenols, especially procyanidin B2 (R 2 = 0.989), even though the chocolates came from varied sources and manufacturers. The relationship was less strong with catechin, and so further work to explore the reasons for this difference was performed. Chiral analysis on a subset of 23 chocolates showed that (-)-epicatechin had a predictive relationship with (+)-catechin in line with the other polyphenols, but not with (-)-catechin (the predominant form). This indicates that (-)-catechin is the most affected by manufacturing conditions, possibly formed through epimerization from (-)-epicatechin during processing. The results show that epicatechin concentrations can be used to predict the content of other polyphenols, especially B2 and C1, and total polyphenols content. Finally, the (-)-catechin content is not predictable from the epicatechin content, and it is concluded that this is the main form of polyphenol that varies according to manufacturing conditions and cocoa origin.

Flavan and procyanidin glycosides from the bark of blackjack oak

Treesearch

Young-Soo Bae; Johann F.W. Burger; Jan P. Steynberg; Daniel Ferreira; Richard W. Hemingway

1994-01-01

The bark of blackjack oak contains (+)-catechin, (-)-epicatechin, (+)-3-O-[β-D-glucopyranosyl]-catechin, catechin-(4α→8}-catechin, epicatechin-(4β→8}-catechin as well as the novel 3-0-[β-D-glucopyranosyl]-catechin-(4α→8)-catechin and 3-0...

Impact of Clonal Variability on Phenolics and Radical Scavenging Activity of Grapes and Wines: A Study on the Recently Developed Merlot and Cabernet Franc Clones (Vitis vinifera L.)

PubMed Central

Pantelić, Milica; Dabić Zagorac, Dragana; Natić, Maja; Gašić, Uroš; Jović, Sonja; Vujović, Dragan; Djordjević, Jelena Popović

2016-01-01

In this study, grapes and corresponding wines of Merlot /No 022, 025 and 029/ and Cabernet Franc /No 02, 010 and 012/ clones (recently developed) were evaluated regarding the total phenolic content, total anthocyanin content, and radical scavenging activity, aiming to better understand their quality and market potential. The nineteen individual polyphenols were quantified in studied grape samples using UHPLC coupled to a triple-quadrupole mass spectrometer. The mother grapes and wines were used as the relevant standards. In the grape, studied characteristics were monitored at three stages of berry development: green berry, véraison and mature berry. The mature grape of clones presented high values of total phenolics (3.81–10.89 g gallic acid equivalent kg-1 frozen weight), anthocyanin content (359.00–1668.18 mg malvidin-3-O-glucoside kg-1 frozen weight) and the radical scavenging activity (41.37–80.48 mmol trolox equivalent kg-1 frozen weight) depending on the clone. Grapes and wines of Merlot No 025 and Cabernet Franc No 010 stood out with the highest values of all three parameters. Generally, the high correlation was observed between TPC and RSA values for green berries and mature grapes, as well as for wine samples. The most abundant phenolics in both Merlot and Cabernet Franc grapes were gallic acid, p-hydroxybenzoic acid, ferulic acid, catechin, epicatechin, gallocatechin gallate, catechin gallate, and rutin. Catechin, epicatechin, epigallocatechin, and catechin gallate, typical for the ripe grape of Merlot and Cabernet Franc clones, showed significant correlation with RSA values. Concentrations of individual polyphenols varied depending on the sample being studied and berry development stages. Merlot No 025 and Cabernet Franc No 010 grapes showed particularly interesting attributes for the production of high quality wines. PMID:27732619

Influence of Grape Seeds and Stems on Wine Composition and Astringency.

PubMed

Pascual, Olga; González-Royo, Elena; Gil, Mariona; Gómez-Alonso, Sergio; García-Romero, Esteban; Canals, Joan Miquel; Hermosín-Gutíerrez, Isidro; Zamora, Fernando

2016-08-31

The aim of this paper is to study the real influence of seeds and stems on wine composition, astringency, and bitterness. A decolored grape juice and a grape juice macerated for 4 days from the same Cabernet Sauvignon grapes were fermented with or without supplementation with 100% seeds, 300% seeds, or 100% stems. Once alcoholic fermentation had finished, the wines were analyzed and tasted. The presence of seeds and stems increased the concentration of flavan-3-ol monomers with respect to the controls. However, the seeds mainly released (+)-catechin and (-)-epicatechin, whereas the stems mainly released (+)-catechin and (+)-gallocatechin. The seeds and stems also released proanthocyanidins; those from seeds have a lower mDP and a high percentage of galloylation, whereas those from stems have a higher mDP and a relatively high percentage of prodelphinidins. The presence of seeds and stems brought about a slight but significant increase in pH and lowered titratable acidity and ethanol content. The presence of seeds boosted color intensity, whereas stems had the opposite effect. Finally, both seeds and stems increased wine astringency and bitterness.

Characterization of Active Anthocyanin Degradation in the Petals of Rosa chinensis and Brunfelsia calycina Reveals the Effect of Gallated Catechins on Pigment Maintenance

PubMed Central

Luo, Honghui; Deng, Shuangfan; Fu, Wei; Zhang, Xin; Zhang, Xuelian; Zhang, Zhaoqi; Pang, Xuequn

2017-01-01

Anthocyanin degradation decreases ornamental or nutritional values of horticultural products. To investigate factors that may influence colour change in flower development, anthocyanin degradation was compared between the flowers of Brunfelsia calycina and Rosa chinensis, which show rapid and slow degradation, respectively. In-gel activity assays, high performance liquid chromatography (HPLC) analysis of tannins, enzyme kinetics measurement and immune-detection of anthocyanin degradation related-perioxidases (PODs) were carried out for the comparison. Rose petals possessed significantly lower anthocyanin degradation-related POD activities than Brunfelsia petals, which may be related to the high tannin contents. Epicatechin gallate (ECG) and gallocatechin gallate (GCG) were detected in rose as 161.3 ± 12.34 and 273.56 ± 41.23 μg/g FW (Fresh Weight) respectively, while not detected in Brunfelsia. ECG and GCG inhibited the activities of the Brunfelsia POD with half maximal inhibitory concentrations (IC50s) as 21.5 and 29.7 μM respectively, and increased the colour intensities of the anthocyanins. Catechin and epicatechin did not inhibit the POD activity, while serving as POD substrates, with Km (the Michaelis constant) as 0.48 and 1.23 mM. Similar protein levels of the anthocyanin degradation-related 40-kDa PODs were detected in Brunfelsia and rose. In summary, high amount of tannins, particularly ECG and GCG, in red rose petals may inhibit the degradation-related enzymes, leading to the maintenance of anthocyanins in vivo. PMID:28346355

Characterization of Active Anthocyanin Degradation in the Petals of Rosa chinensis and Brunfelsia calycina Reveals the Effect of Gallated Catechins on Pigment Maintenance.

PubMed

Luo, Honghui; Deng, Shuangfan; Fu, Wei; Zhang, Xin; Zhang, Xuelian; Zhang, Zhaoqi; Pang, Xuequn

2017-03-25

Anthocyanin degradation decreases ornamental or nutritional values of horticultural products. To investigate factors that may influence colour change in flower development, anthocyanin degradation was compared between the flowers of Brunfelsia calycina and Rosa chinensis , which show rapid and slow degradation, respectively. In-gel activity assays, high performance liquid chromatography (HPLC) analysis of tannins, enzyme kinetics measurement and immune-detection of anthocyanin degradation related-perioxidases (PODs) were carried out for the comparison. Rose petals possessed significantly lower anthocyanin degradation-related POD activities than Brunfelsia petals, which may be related to the high tannin contents. Epicatechin gallate (ECG) and gallocatechin gallate (GCG) were detected in rose as 161.3 ± 12.34 and 273.56 ± 41.23 μg/g FW (Fresh Weight) respectively, while not detected in Brunfelsia . ECG and GCG inhibited the activities of the Brunfelsia POD with half maximal inhibitory concentrations (IC50s) as 21.5 and 29.7 μM respectively, and increased the colour intensities of the anthocyanins. Catechin and epicatechin did not inhibit the POD activity, while serving as POD substrates, with K m (the Michaelis constant) as 0.48 and 1.23 mM. Similar protein levels of the anthocyanin degradation-related 40-kDa PODs were detected in Brunfelsia and rose. In summary, high amount of tannins, particularly ECG and GCG, in red rose petals may inhibit the degradation-related enzymes, leading to the maintenance of anthocyanins in vivo.

Antioxidant activity and diffusion of catechin and epicatechin from antioxidant active films made of poly(L-lactic acid).

PubMed

Iñiguez-Franco, Fabiola; Soto-Valdez, Herlinda; Peralta, Elizabeth; Ayala-Zavala, J Fernando; Auras, Rafael; Gámez-Meza, Nohemí

2012-07-04

Active membranes and food packaging containing antioxidants like catechin and epicatechin, combined with the use of materials made of biopolymers obtained from renewable sources, could create a novel alternative to reduce oxidation in food, pharmaceutical, and cosmetic products. Poly(94% L-lactic acid) films containing 1.28% catechin and 1.50% epicatechin were extruded in a pilot plant-scale extrusion machine. The diffusion kinetics of catechin and epicatechin into 95% ethanol at 20, 30, 40, and 50 °C and 50% ethanol at 40 °C displayed Fickian release behavior and diffusion coefficients between 0.5 and 50 × 10(-11) cm(2)/s. According to the Arrhenius equation, the energy of activation for the diffusion of catechin and epicatechin in the films was 110.43 and 98.92 kJ/mol, respectively. The antioxidant activity of the films was measured in methanol extracts containing 46.42 μg/mL of catechin and 57.52 μg/mL of epicatechin as 32.90 and 36.68% of scavenging the 2,2-diphenyl-1-picrylhydrazyl radical, respectively.

Polymeric proanthocyanidins: Interflavanoid linkage isomerism in (epicatechin-4)-(epicatechin-4)-catechin procyanidins

Treesearch

Richard W. Hemingway; L. Yeap Foo; L. J. Porter

1981-01-01

Procyanidin trimers have been isolated from a variety of plants,1-3 but their structures remain unresolved. We have now isolated three configurational isomers of (epicatechin-4)-(epicatechin-4)-catechin from Pinus taeda L. (loblolly pine) phloem which exhibit isomerism of the interflavanoid linkages.

A facile inhibitor screening of SARS coronavirus N protein using nanoparticle-based RNA oligonucleotide.

PubMed

Roh, Changhyun

2012-01-01

Hundreds of million people worldwide have been infected with severe acute respiratory syndrome (SARS), and the rate of global death from SARS has remarkably increased. Hence, the development of efficient drug treatments for the biological effects of SARS is highly needed. We have previously shown that quantum dots (QDs)-conjugated RNA oligonucleotide is sensitive to the specific recognition of the SARS-associated coronavirus (SARS-CoV) nucleocapsid (N) protein. In this study, we found that a designed biochip could analyze inhibitors of the SARS-CoV N protein using nanoparticle-based RNA oligonucleotide. Among the polyphenolic compounds examined, (-)-catechin gallate and (-)-gallocatechin gallate demonstrated a remarkable inhibition activity on SARS-CoV N protein. (-)-catechin gallate and (-)-gallocatechin gallate attenuated the binding affinity in a concentrated manner as evidenced by QDs-conjugated RNA oligonucleotide on a designed biochip. At a concentration of 0.05 μg mL(-1), (-)-catechin gallate and (-)-gallocatechin gallate showed more than 40% inhibition activity on a nanoparticle-based RNA oligonucleotide biochip system.

Flavanol monomer-induced changes to the human faecal microflora.

PubMed

Tzounis, Xenofon; Vulevic, Jelena; Kuhnle, Gunter G C; George, Trevor; Leonczak, Jadwiga; Gibson, Glenn R; Kwik-Uribe, Catherine; Spencer, Jeremy P E

2008-04-01

We have investigated the bacterial-dependent metabolism of ( - )-epicatechin and (+)-catechin using a pH-controlled, stirred, batch-culture fermentation system reflective of the distal region of the human large intestine. Incubation of ( - )-epicatechin or (+)-catechin (150 mg/l or 1000 mg/l) with faecal bacteria, led to the generation of 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone, 5-phenyl-gamma-valerolactone and phenylpropionic acid. However, the formation of these metabolites from (+)-catechin required its initial conversion to (+)-epicatechin. The metabolism of both flavanols occurred in the presence of favourable carbon sources, notably sucrose and the prebiotic fructo-oligosaccharides, indicating that bacterial utilisation of flavanols also occurs when preferential energy sources are available. (+)-Catechin incubation affected the growth of select microflora, resulting in a statistically significant increase in the growth of the Clostridium coccoides-Eubacterium rectale group, Bifidobacterium spp. and Escherichia coli, as well as a significant inhibitory effect on the growth of the C. histolyticum group. In contrast, the effect of ( - )-epicatechin was less profound, only significantly increasing the growth of the C. coccoides-Eubacterium rectale group. These potential prebiotic effects for both (+)-catechin and ( - )-epicatechin were most notable at the lower concentration of 150 mg/l. As both ( - )-epicatechin and (+)-catechin were converted to the same metabolites, the more dramatic change in the growth of distinct microfloral populations produced by (+)-catechin incubation may be linked to the bacterial conversion of (+)-catechin to (+)-epicatechin. Together these data suggest that the consumption of flavanol-rich foods may support gut health through their ability to exert prebiotic actions.

Structural characteristics for superoxide anion radical scavenging and productive activities of green tea polyphenols including proanthocyanidin dimers.

PubMed

Sato, Masashi; Toyazaki, Hajime; Yoshioka, Yu; Yokoi, Nobutoshi; Yamasaki, Toru

2010-01-01

The purpose of this paper is to report structural characteristics for superoxide anion radical (O(2(-))) scavenging and productive activities of green tea polyphenols. (-)-Epicatechin 3-O-gallate (5), (-)-epigallocatechin (6), (-)-epigallocatechin 3-O-gallate (7), (+)-gallocatechin-(4alpha-->8')-epigallocatechin (8), and (-)-epigallocatechin-(2beta-->O-->7', 4beta-->8')-epicatechin 3'-O-gallate (9) were isolated from the tea plant Camellia sinensis L. (+)-Epigallocatechin-(2beta-->O-->7, 4beta-->8')-epicatechin (10) was prepared by hydrolyzing 9. The polyphenols, as well as commercially available pyrogallol (1), methyl gallate (2), (+)-catechin (3), (-)-epicatechin (4), and the flavonol myricetin (11), produced O(2(-)) in descending order 1, 6 asymptotically equal to11 asymptotically equal to8, 7, 10, 2 asymptotically equal to9, 5 asymptotically equal to4. In the polyphenols with the pyrogallol-type B-ring and/or galloyl group, electron-withdrawing substituents (carbonyl and ketal carbons) and/or intramolecular hydrogen bonding constituted structural characteristics against the autoxidation reaction. The O(2(-))-productive activity partially counteracted O(2(-))-scavenging activity. However, such structural characteristics appeared to enhance the scavenging activity, accordingly the polyphenols in effect served as O(2(-))-scavengers in descending order 9 asymptotically equal to7, 2, 11, 8, 10, 3 asymptotically equal to4. On the other hand, 6, having no such structural characteristic, acted as a O(2(-))-generator, as well as 1. Further assessments covering tannins (e.g., A-type proanthocyanidin dimer 9) are needed to identify which green tea polyphenols are the most desirable chemopreventive agents.

Heterogenous fluorescence decay of (4→6)-and (4→8)-linked dimers of (+)-catechin and (-) epicatechin as a result of rotational isomerism.

Treesearch

Wolfgang R. Bergmann; Mary D. Barkley; Richard W. Hemingway; Wayne Mattice

1987-01-01

The time-resolved fluorescence of (+)-catechin and ( -)-epicatechin decays as a single exponential. In contrast dimers formed from (+)-catechin and (-)-epicatechin have more complex decays unless rotation about the interflavan bond is constrained by the introduction of a new ring. The fluorescence decay in unconstrained dimers is adequately described by the sum of two...

Simultaneous determination of theobromine, (+)-catechin, caffeine, and (-)-epicatechin in standard reference material baking chocolate 2384, cocoa, cocoa beans, and cocoa butter.

PubMed

Risner, Charles H

2008-01-01

A reverse-phase liquid chromatography analysis is used to access the quantity of theobromine, (+)-catechin, caffeine, and (-)-epicatechin in Standard Reference Material 2384 Baking Chocolate, cocoa, cocoa beans, and cocoa butter using water or a portion of the mobile phase as the extract. The procedure requires minimal sample preparation. Theobromine, (+)-catechin, caffeine, and (-)-epicatechin are detected by UV absorption at 273 nm after separation using a 0.3% acetic acid-methanol gradient (volume fractions) and quantified using external standards. The limit of detection for theobromine, (+)-catechin, caffeine, and (-)-epicatechin averages 0.08, 0.06, 0.06, and 0.06 microg/mL, respectively. The method when applied to Standard Reference Material 2384 Baking Chocolate; baking chocolate reference material yields results that compare to two different, separate procedures. Theobromine ranges from 26000 mg/kg in cocoa to 140 mg/kg in cocoa butter; (+)-catechin from 1800 mg/kg in cocoa to below detection limits of < 32 mg/kg in cocoa butter; caffeine from 2400 mg/kg in cocoa to 400 mg/kg in cocoa butter, and (-)-epicatechin from 3200 mg/kg in cocoa to BDL, < 27 mg/kg, in cocoa butter. The mean recoveries from cocoa are 102.4 +/- 0.6% for theobromine, 100.0 +/- 0.6 for (+)-catechin, 96.2 +/- 2.1 for caffeine, and 106.2 +/- 1.7 for (-)-epicatechin.

Conformational analysis and dipole moments of tetra-O-methyl-(+)-catechin and tetra-O-methyl_(-)-epicatechin

Treesearch

W.L. Mattice; F.L. Tobiason; K. Houghlum; A. Shanafelt

1982-01-01

A conformational energy analysis has been performed for tetra-0-methyl-(+)-catechin and tetra-O-methyl-(-)-epicatechin. Rotation was permitted about five C-O bonds and about the single bond connecting two rings. Eighteen rotational isomers each were assigned for tetra-0-methyl-(-)-epicatechin. Relative...

Transcripts of Anthocyanidin Reductase and Leucoanthocyanidin Reductase and Measurement of Catechin and Epicatechin in Tartary Buckwheat

PubMed Central

Kim, Yeon Bok; Thwe, Aye Aye; Kim, YeJi; Li, Xiaohua; Cho, Jin Woong; Park, Phun Bum; Valan Arasu, Mariadhas; Abdullah Al-Dhabi, Naif; Kim, Sun-Ju; Suzuki, Tastsuro; Hyun Jho, Kwang; Park, Sang Un

2014-01-01

Anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR) play an important role in the monomeric units biosynthesis of proanthocyanidins (PAs) such as catechin and epicatechin in several plants. The aim of this study was to clone ANR and LAR genes involved in PAs biosynthesis and examine the expression of these two genes in different organs under different growth conditions in two tartary buckwheat cultivars, Hokkai T8 and T10. Gene expression was carried out by quantitative real-time RT-PCR, and catechin and epicatechin content was analyzed by high performance liquid chromatography. The expression pattern of ANR and LAR did not match the accumulation pattern of PAs in different organs of two cultivars. Epicatechin content was the highest in the flowers of both cultivars and it was affected by light in only Hokkai T8 sprouts. ANR and LAR levels in tartary buckwheat might be regulated by different mechanisms for catechin and epicatechin biosynthesis under light and dark conditions. PMID:24605062

Preparation of A-type proanthocyanidin dimers from peanut skins and persimmon pulp and comparison of the antioxidant activity of A-type and B-type dimers.

PubMed

Dong, Xiao-qian; Zou, Bo; Zhang, Ying; Ge, Zhen-zhen; Du, Jing; Li, Chun-mei

2013-12-01

We have established a simple method for preparing large quantities of A-type dimers from peanut skin and persimmon for further structure-activity relationship study. Peanut skins were defatted with hexane and oligomeric proanthocyanidins were extracted from it with 20% of methanol, and the extract was fractionated with ethyl acetate. Persimmon tannin was extracted from persimmon with methanol acidified with 1% hydrochloric acid, after removing the sugar and small phenols, the high molecular weight persimmon tannin was partially cleaved with 6.25% hydrochloric acid in methanol. The ethyl acetate fraction from peanut skins and persimmon tannin cleaved products was chromatographed on AB-8 macroporous resin followed by Toyopearl HW-50F resin to yield about 378.3mg of A-type (epi)catechin (EC) dimer from 1 kg dry peanut skins and 34.3mg of A-type (epi)catechin-3-O-gallate (ECG) dimer and 37.7 mg of A-type (epi)gallocatechin-3-O-gallate (EGCG) dimer from 1 kg fresh persimmon fruit. The antioxidant properties of the A-type and B-type dimers were compared in five different assays, namely, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical, hydroxyl radical, lipid peroxidation in mice liver homogenate and erythrocyte hemolysis in rat blood. Our results showed that both A-type and B-type dimers showed high antioxidant potency in a dose-dependent manner. In general, B-type dimers showed higher radical scavenging potency than A-type ones with the same subunits in aqueous systems. But in tissue or lipid systems, A-type dimers showed similar or even higher antioxidant potency than B-type ones. © 2013.

Striking changes in tea metabolites due to elevational effects.

PubMed

Kfoury, Nicole; Morimoto, Joshua; Kern, Amanda; Scott, Eric R; Orians, Colin M; Ahmed, Selena; Griffin, Timothy; Cash, Sean B; Stepp, John Richard; Xue, Dayuan; Long, Chunlin; Robbat, Albert

2018-10-30

Climate effects on crop quality at the molecular level are not well-understood. Gas and liquid chromatography-mass spectrometry were used to measure changes of hundreds of compounds in tea at different elevations in Yunnan Province, China. Some increased in concentration while others decreased by 100's of percent. Orthogonal projection to latent structures-discriminant analysis revealed compounds exhibiting analgesic, antianxiety, antibacterial, anticancer, antidepressant, antifungal, anti-inflammatory, antioxidant, anti-stress, and cardioprotective properties statistically (p = 0.003) differentiated high from low elevation tea. Also, sweet, floral, honey-like notes were higher in concentration in the former while the latter displayed grassy, hay-like aroma. In addition, multivariate analysis of variance showed low elevation tea had statistically (p = 0.0062) higher concentrations of caffeine, epicatechin gallate, gallocatechin, and catechin; all bitter compounds. Although volatiles represent a small fraction of the total mass, this is the first comprehensive report illustrating how normal variations in temperature, 5 °C, due to elevational effects impact tea quality. Copyright © 2018 Elsevier Ltd. All rights reserved.

Separation of polyphenols and caffeine from the acetone extract of fermented tea leaves (Camellia sinensis) using high-performance countercurrent chromatography.

PubMed

Choi, Soo Jung; Hong, Yong Deog; Lee, Bumjin; Park, Jun Seong; Jeong, Hyun Woo; Kim, Wan Gi; Shin, Song Seok; Yoon, Kee Dong

2015-07-21

Leaves from Camellia sienensis are a popular natural source of various beverage worldwide, and contain caffeine and polyphenols derived from catechin analogues. In the current study, caffeine (CAF, 1) and three tea polyphenols including (-)-epigallocatechin 3-O-gallate (EGCg, 2), (-)-gallocatechin 3-O-gallate (GCg, 3), and (-)-epicatechin 3-O-gallate (ECg, 4) were isolated and purified by flow-rate gradient high-performance countercurrent chromatography (HPCCC) using a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:9:1:9, v/v). Two hundred milligrams of acetone-soluble extract from fermented C. sinensis leaves was separated by HPCCC to give 1 (25.4 mg), 2 (16.3 mg), 3 (11.1 mg) and 4 (4.4 mg) with purities over 98%. The structures of 1-4 were elucidated by QTOF-MS, as well as 1H- and 13C-NMR, and the obtained data were compared to the previously reported values.

Relationship in between Chemical Oxidation and Browning of Flavanols

NASA Astrophysics Data System (ADS)

Dong, X.; Zhang, Y. L.; Wang, F.; Pang, M. X.; Qi, J. H.

2016-08-01

Catechin, epicatechin and chlorogenic acid are widely distributed in the plant kingdom. At present, influencing factors of phenol chemical oxidation is little research. In order to study non-enzymatic browning factors, this research utilized catechin, epicatechin and chlorogenic acid to establish simulation systems. The browning degree and products of flavanols were investigated by transmittance and high-performance liquid chromatography (HPLC). The main results and conclusions were follows. The brown generation is increased after phenols of chemical oxidation at 50°C and at pH 3.7 phosphate buffered saline, the sequence of influencing factor of browning is pH > kind of phenol > temperature. Oxidation of compounds of catechin and epicatechin results in formation of their Methylene quinone or o -Quinones. In addition, oxidation products of catechin, epicatechin and chlorogenic acid were mixture of different molecular sizes. The research has showed that brown generation correlated well with chemical oxidation of phenols and chemical oxidation reaction generated larger molecular weight polymers.

Quantification of the predominant monomeric catechins in baking chocolate standard reference material by LC/APCI-MS.

PubMed

Nelson, Bryant C; Sharpless, Katherine E

2003-01-29

Catechins are polyphenolic plant compounds (flavonoids) that may offer significant health benefits to humans. These benefits stem largely from their anticarcinogenic, antioxidant, and antimutagenic properties. Recent epidemiological studies suggest that the consumption of flavonoid-containing foods is associated with reduced risk of cardiovascular disease. Chocolate is a natural cocoa bean-based product that reportedly contains high levels of monomeric, oligomeric, and polymeric catechins. We have applied solid-liquid extraction and liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometry to the identification and determination of the predominant monomeric catechins, (+)-catechin and (-)-epicatechin, in a baking chocolate Standard Reference Material (NIST Standard Reference Material 2384). (+)-Catechin and (-)-epicatechin are detected and quantified in chocolate extracts on the basis of selected-ion monitoring of their protonated [M + H](+) molecular ions. Tryptophan methyl ester is used as an internal standard. The developed method has the capacity to accurately quantify as little as 0.1 microg/mL (0.01 mg of catechin/g of chocolate) of either catechin in chocolate extracts, and the method has additionally been used to certify (+)-catechin and (-)-epicatechin levels in the baking chocolate Standard Reference Material. This is the first reported use of liquid chromatography/mass spectrometry for the quantitative determination of monomeric catechins in chocolate and the only report certifying monomeric catechin levels in a food-based Standard Reference Material.

Protein Surface Structural Recognition in Inactive Areas: A New Immobilization Strategy for Acetylcholinesterase.

PubMed

Diao, Jianxiong; Yu, Xiaolu; Ma, Lin; Li, Yuanqing; Sun, Ying

2018-05-16

This work reported a new method of design for the immobilization of acetylcholinesterase (AChE) based on its molecular structure to improve its sensitivity and stability. The immobilization binding site on the surface of AChE was determined using MOLCAD's multi-channel functionality. Then, 11 molecules ((+)-catechin, (-)-epicatechin, (-)-gallocatechin, hesperetin, naringenin, quercetin, taxifolin, (-)-epicatechin gallate, flupirtine, atropine, and hyoscyamine) were selected from the ZINC database (about 50 000 molecules) as candidate affinity ligands for AChE. The fluorescence results showed that the binding constant K b between AChE and the ligands ranged from 0.01344 × 10 4 to 4.689 × 10 4 M -1 and there was one independent class of binding site for the ligands on AChE. The AChE-ligand binding free energy ranged from -12.14 to -26.65 kJ mol -1 . Naringenin, hesperetin, and quercetin were the three most potent immobilized affinity ligands. In addition, it was confirmed that the binding between the immobilized ligands only occurred at a single site, located in an inactive area on the surface of AChE, and did not affect the enzymatic activity as shown through a competition experiment and enzyme assay. This method based on protein surface structural recognition with high sensitivity and stability can be used as a generic approach for design of the enzyme immobilization and biosensor development.

(-)-Catechin in cocoa and chocolate: occurrence and analysis of an atypical flavan-3-ol enantiomer.

PubMed

Kofink, Michael; Papagiannopoulos, Menelaos; Galensa, Rudolf

2007-07-04

Cocoa contains high levels of different flavonoids. In the present study, the enantioseparation of catechin and epicatechin in cocoa and cocoa products by chiral capillary electrophoresis (CCE) was performed. A baseline separation of the catechin and epicatechin enantiomers was achieved by using 0.1 mol x L(-1) borate buffer (pH 8.5) with 12 mmol x L(-1) (2-hydroxypropyl)-gamma-cyclodextrin as chiral selector, a fused-silica capillary with 50 cm effective length (75 microm I.D.), +18 kV applied voltage, a temperature of 20 degrees C and direct UV detection at 280 nm. To avoid comigration or coelution of other similar substances, the flavan-3-ols were isolated and purified using polyamide-solid-phase-extraction and LC-MS analysis. As expected, we found (-)-epicatechin and (+)-catechin in unfermented, dried, unroasted cocoa beans. In contrast, roasted cocoa beans and cocoa products additionally contained the atypical flavan-3-ol (-)-catechin. This is generally formed during the manufacturing process by an epimerization which converts (-)-epicatechin to its epimer (-)-catechin. High temperatures during the cocoa bean roasting process and particularly the alkalization of the cocoa powder are the main factors inducing the epimerization reaction. In addition to the analysis of cocoa and cocoa products, peak ratios were calculated for a better differentiation of the cocoa products.

Effects of green tea catechins on gramicidin channel function and inferred changes in bilayer properties

PubMed Central

Ingólfsson, Helgi I.; Koeppe, Roger E.; Andersen, Olaf S.

2011-01-01

Green tea's health benefits have been attributed to its major polyphenols, the catechins: (−)-epigallocatechin gallate (EGCG), (−)-epicatechin gallate (ECG), (−)-epigallocatechin (EGC), and epicatechin (EC). Catechins (especially EGCG) modulate a wide range of biologically important molecules, including many membrane proteins. Yet, little is known about their mechanism(s) of action. We tested the catechins' bilayer-modifying potency using gramicidin A (gA) channels as molecular force probes. All the catechins alter gA channel function and modify bilayer properties, with a 500-fold range in potency (EGCG > ECG >> EGC > EC). Additionally, the gallate group causes current block, as evident by brief downward current transitions (flickers). PMID:21896274

Phenolic metabolites in plasma and tissues of rats fed with a grape pomace extract as assessed by liquid chromatography-tandem mass spectrometry.

PubMed

Rodriguez Lanzi, Cecilia; Perdicaro, Diahann J; Antoniolli, Andrea; Piccoli, Patricia; Vazquez Prieto, Marcela A; Fontana, Ariel

2018-05-31

Grape pomace extract (GPE) is a rich and relatively low-cost source of phenolic compounds. However, little is known about the main GPE metabolites in mammals, which could help explain the observed health-promoting effects. This study investigated the presence of parent compounds from flavanol, flavonol and stilbene families and their metabolites in rat plasma and tissues after an acute intake of GPE in doses of 300 and 600 mg kg/body weight. The measurement of free compounds and their metabolites was performed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Results showed the presence of epicatechin, epicatechin methyl-glucuronide, epicatechin methyl-sulphate, catechin, catechin-glucuronide, quercetin methyl-glucuronide, resveratrol-3-glucuronide, resveratrol-4-glucuronide and resveratrol-3-sulphate in plasma, which was dose dependent. The most abundant measured compound in plasma was epicatechin-glucuronide. The presence of glucuronidated and methyl-glucuronidated forms of catechin were observed in the liver at both doses, while epicatechin-glucuronide and methyl-glucuronide were detected only upon intake of 600 mg GPE/kg body weight. At this dose epicatechin-glucuronide and methyl-glucuronide were also detected in muscle, and catechin methyl-glucuronide in adipose tissue. Results show the main GPE metabolites present in rat tissues after oral consumption, contributing to better understand the health benefits of GPE and its potential utilization as a functional ingredient. Copyright © 2018. Published by Elsevier Inc.

Lingonberry (Vaccinium vitis-idaea) and European cranberry (Vaccinium microcarpon) proanthocyanidins: isolation, identification, and bioactivities.

PubMed

Kylli, Petri; Nohynek, Liisa; Puupponen-Pimiä, Riitta; Westerlund-Wikström, Benita; Leppänen, Tiina; Welling, Jukka; Moilanen, Eeva; Heinonen, Marina

2011-04-13

European, small-fruited cranberries (Vaccinium microcarpon) and lingonberries (Vaccinium vitis-idaea) were characterized for their phenolic compounds and tested for antioxidant, antimicrobial, antiadhesive, and antiinflammatory effects. The main phenolic compounds in both lingonberries and cranberries were proanthocyanidins comprising 63-71% of the total phenolic content, but anthocyanins, hydroxycinnamic acids, hydroxybenzoic acids, and flavonols were also found. Proanthocyanidins are polymeric phenolic compounds consisting mainly of catechin, epicatechin, gallocatechin, and epigallocatechin units. In the present study, proanthocyanidins were divided into three groups: dimers and trimers, oligomers (mDP 4-10), and polymers (mDP > 10). Catechin, epicatechin, A-type dimers and trimers were found to be the terminal units of isolated proanthocyanidin fractions. Inhibitions of lipid oxidation in liposomes were over 70% and in emulsions over 85%, and in most cases the oligomeric or polymeric fraction was the most effective. Polymeric proanthocyanidin extracts of lingonberries and cranberries were strongly antimicrobial against Staphylococcus aureus, whereas they had no effect on other bacterial strains such as Salmonella enterica sv. Typhimurium, Lactobacillus rhamnosus and Escherichia coli. Polymeric fraction of cranberries and oligomeric fractions of both lingonberries and cranberries showed an inhibitory effect on hemagglutination of E. coli, which expresses the M hemagglutin. Cranberry phenolic extract inhibited LPS-induced NO production in a dose-dependent manner, but it had no major effect on iNOS of COX-2 expression. At a concentration of 100 μg/mL cranberry phenolic extract inhibited LPS-induced IL-6, IL-1β and TNF-α production. Lingonberry phenolics had no significant effect on IL-1β production but inhibited IL-6 and TNF-α production at a concentration of 100 μg/mL similarly to cranberry phenolic extract. In conclusion the phenolics, notably proanthocyanidins (oligomers and polymers), in both lingonberries and cranberries exert multiple bioactivities that may be exploited in food development.

Simultaneous analysis of tea catechins, caffeine, gallic acid, theanine and ascorbic acid by micellar electrokinetic capillary chromatography.

PubMed

Aucamp, J P; Hara, Y; Apostolides, Z

2000-04-21

A micellar electrokinetic capillary chromatography (MEKC) method for the simultaneous analysis of five tea catechins, theanine, caffeine, gallic acid and ascorbic acid has been developed. The catechins are (-)-epicatechin, (+)-catechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate. p-Nitrophenol serves as both reference and internal standard. All the components are separated within 13 min with a 57 cm uncoated fused-silica column. On-column detection was carried out at 200 nm. This method has been used to measure these compounds in fresh tea leaves and tea liquor. The limit of detection for all analytes ranged from 1 to 20 microg/ml.

Using High Throughput Screens to Identify Lead Compounds for Alzheimer’s Disease Therapeutics

DTIC Science & Technology

2008-11-01

showed that six red wine polyphenols, myricetin, morin, quercetin , kaemphferol, catechin and epicatechin were able to dose dependently inhibit formation...O OH OHHO morin OHO OH O OH OH OH quercetin OHO OH O OH OH kaempf erol OHO OH O OH OH (+)-catechin OHO OH O OH OH (-)-epicatechin OHO OH OH OH OH O O

Method for the determination of catechin and epicatechin enantiomers in cocoa-based ingredients and products by high-performance liquid chromatography: single-laboratory validation.

PubMed

Machonis, Philip R; Jones, Matthew A; Schaneberg, Brian T; Kwik-Uribe, Catherine L

2012-01-01

A single-laboratory validation study was performed for an HPLC method to identify and quantify the flavanol enantiomers (+)- and (-)-epicatechin and (+)- and (-)-catechin in cocoa-based ingredients and products. These compounds were eluted isocratically with an ammonium acetate-methanol mobile phase applied to a modified beta-cyclodextrin chiral stationary phase and detected using fluorescence. Spike recovery experiments using appropriate matrix blanks, along with cocoa extract, cocoa powder, and dark chocolate, were used to evaluate accuracy, repeatability, specificity, LOD, LOQ, and linearity of the method as performed by a single analyst on multiple days. In all samples analyzed, (-)-epicatechin was the predominant flavanol and represented 68-91% of the total monomeric flavanols detected. For the cocoa-based products, within-day (intraday) precision for (-)-epicatechin was between 1.46-3.22%, for (+)-catechin between 3.66-6.90%, and for (-)-catechin between 1.69-6.89%; (+)-epicatechin was not detected in these samples. Recoveries for the three sample types investigated ranged from 82.2 to 102.1% at the 50% spiking level, 83.7 to 102.0% at the 100% spiking level, and 80.4 to 101.1% at the 200% spiking level. Based on performance results, this method may be suitable for routine laboratory use in analysis of cocoa-based ingredients and products.

The Galloyl Catechins Contributing to Main Antioxidant Capacity of Tea Made from Camellia sinensis in China

PubMed Central

Zhao, Chunjian; Li, Chunying; Liu, Shuaihua; Yang, Lei

2014-01-01

Total polyphenol content, catechins content, and antioxidant capacities of green, dark, oolong, and black teas made from Camellia sinensis in China were evaluated. The total polyphenol content of 20 samples of tea was in the range of 7.82–32.36%. Total catechins content was in the range of 4.34–24.27%. The antioxidant capacity of tea extract was determined by the oxygen radical absorbance capacity (ORAC) test and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging test. Total polyphenol content, catechins content, and antioxidant capacity decreased in the following order: green > oolong > black > dark tea. A positive correlation existed between the antioxidant capacity and total polyphenol content or catechins content (R 2 = 0.67–0.87). The antioxidant capacities of five major catechins (epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epicatechin, epigallocatechin, and catechin) were determined by online HPLC DPPH radical-scavenging; the antioxidant activity of tea was mainly attributed to the esterified catechins (EGCG or ECG). PMID:25243234

Profiling of lipophilic and phenolic phytochemicals of four cultivars from cherimoya (Annona cherimola Mill.).

PubMed

Santos, Sónia A O; Vilela, Carla; Camacho, João F; Cordeiro, Nereida; Gouveia, Manuela; Freire, Carmen S R; Silvestre, Armando J D

2016-11-15

The lipophilic and phenolic extractives of the ripe mesocarp of four cherimoya cultivars ('Perry Vidal', 'Mateus I', 'Mateus III' and 'Funchal') from Madeira Island, were studied for the first time. The predominant lipophilic compounds are kaurene diterpenes (42.2-59.6%), fatty acids (18.0-35.6%) and sterols (9.6-23.7%). Kaur-16-en-19-oic acid is the major lipophilic component of all cultivars accounting between 554 and 1350mgkg(-1) of dry material. The studied fruits also contain a high variety of flavan-3-ols, including galloylated and non-galloylated compounds. Five phenolic compounds were identified for the first time: catechin, (epi)catechin-(epi)gallocatechin, (epi)gallocatechin, (epi)afzelechin-(epi)catechin and procyanidin tetramer. 'Mateus I' and 'Mateus III' cultivars present the highest content of phenolic compounds (6299 and 9603mgkg(-1) of dry weight, respectively). These results support the use of this fruit as a rich source of health-promoting components, with the capacity to prevent or delay the progress of oxidative-stress related disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Effects of sanguisorba tannins and saponins compatibility on pharmacokinetic parameters of catechin, epicatechin and ziyuglycoside Ⅰ in rats].

PubMed

Xiong, Yong-Ai; Yang, Ming

2016-10-01

To study the effects of sanguisorba tannins and saponins compatibility at different proportions [tannins-saponins (1∶1) and tannins-saponins(8∶1)] after intragastric administration (50 mg•kg⁻¹) on pharmacokinetic parameters of catechin, epicatechin and ziyuglycoside Ⅰ in rats by using pharmacokinetic techniques and methods. Kinetica 5.0 software was used to calculate the pharmacokinetic parameters. The results showed that the specificity, linearity, recovery rate, precision and stability of the established detection method were in line with the test requirements. When the sanguisorba tannins and eaponins were combined at the rate of 1∶1, Vd and CL of catechin and epicatechin were increased significantly（P<0.05); MRT was significantly shortened(P<0.05); Cmax and AUC were significantly reduced(P<0.05). When the sanguisorba tannins and saponins were combined at the rate of 8∶1, Vd and CL of catechin and epicatechin were significantly reduced(P<0.05); MRT was significantly prolonged(P<0.05); Cmax and AUC were increased significantly(P<0.05). In addition, with the increase in proportion of sanguisorba tannins in the compatibility, Cmax and AUC of ziyuglycoside Ⅰ were increased significantly(P<0.05); Vd and CL were significantly reduced(P<0.05), Tmax was obviously lagging behind, and MRT was also significantly prolonged(P<0.05). In our present study, catechin, epicatechin and ziyuglycoside Ⅰ showed good pharmacokinetic behavior in rats when sanguisorba tannins and saponins were combined at the rate of 8∶1 in compatibility, which could be used as a reference for the proportion in sanguisorba tannins and saponins compatibility. Copyright© by the Chinese Pharmaceutical Association.

An industry consensus study on an HPLC fluorescence method for the determination of (±)-catechin and (±)-epicatechin in cocoa and chocolate products.

PubMed

Shumow, Laura; Bodor, Alison

2011-07-05

This manuscript describes the results of an HPLC study for the determination of the flavan-3-ol monomers, (±)-catechin and (±)-epicatechin, in cocoa and plain dark and milk chocolate products. The study was performed under the auspices of the National Confectioners Association (NCA) and involved the analysis of a series of samples by laboratories of five member companies using a common method. The method reported in this paper uses reversed phase HPLC with fluorescence detection to analyze (±)-epicatechin and (±)-catechin extracted with an acidic solvent from defatted cocoa and chocolate. In addition to a variety of cocoa and chocolate products, the sample set included a blind duplicate used to assess method reproducibility. All data were subjected to statistical analysis with outliers eliminated from the data set. The percent coefficient of variation (%CV) of the sample set ranged from approximately 7 to 15%. Further experimental details are described in the body of the manuscript and the results indicate the method is suitable for the determination of (±)-catechin and (±)-epicatechin in cocoa and chocolate products and represents the first collaborative study of this HPLC method for these compounds in these matrices.

Procyanidins (Condensed Tannins) in Green Cell Suspension Cultures of Douglas Fir Compared with Those in Strawberry and Avocado Leaves by Means of C18-Reversed-phase Chromatography 1

PubMed Central

Stafford, Helen A.; Lester, Hope H.

1980-01-01

The procyanidins (the most common type of proanthocyanidin or condensed tannin) from cell suspension cultures derived from cotyledons of Douglas Fir have been compared with those isolated from leaves of strawberry and avocado. Seventy per cent methanol (v/v) extracts from 100 milligrams fresh weight samples were analyzed by a combination of C18-reversed-phase columns with high-performance liquid chromatography, and normal phase paper chromatography. (−)-Epicatechin and its oligomers were generally retarded longer on C18 columns than the corresponding units made of (+)-catechin when eluted with solvents made up of 5% acetic acid alone or mixed with methanol up to 15% (v/v). Douglas fir preparations contained the most complex set of procyanidins and consisted of oligomers of catechin and epicatechin, whereas strawberry and avocado contained mainly (+)-catechin and (−)-epicatechin derivatives, respectively. PMID:16661581

Comparison of effects of green tea catechins on apicomplexan hexose transporters and mammalian orthologues.

PubMed

Slavic, Ksenija; Derbyshire, Elvira T; Naftalin, Richard J; Krishna, Sanjeev; Staines, Henry M

2009-11-01

Here we have investigated the inhibitory properties of green tea catechins on the Plasmodium falciparum hexose transporter (PfHT), the Babesia bovis hexose transporter 1 (BboHT1) and the mammalian facilitative glucose transporters, GLUT1 and GLUT5, expressed in Xenopus laevis oocytes. (-)-Epicatechin-gallate (ECG) and (-)-epigallocatechin-gallate (EGCG) inhibited D-glucose transport by GLUT1 and PfHT, and D-fructose transport by GLUT5, with apparent K(i) values between 45 and 117 microM. BboHT1 was more potently inhibited by the ungallated catechins (-)-epicatechin (EC) and (-)-epigallocatechin (EGC), with apparent K(i) values of 108 and 168 microM, respectively. Site-directed mutagenesis experiments provided little further support for previously reported models of catechin binding to hexose transporters. Furthermore, P. falciparum growth inhibition by catechins was not affected by the external D-glucose concentration. Our results provide new data on the inhibitory action of catechins against sugar transporters but were unable to elucidate the antimalarial mechanism of action of these agents.

Elevated plasma and urinary concentrations of green tea catechins associated with improved plasma lipid profile in healthy Japanese women.

PubMed

Takechi, Ryusuke; Alfonso, Helman; Hiramatsu, Naoko; Ishisaka, Akari; Tanaka, Akira; Tan, La'Belle; Lee, Andy H

2016-03-01

This study investigated green tea catechins in plasma and urine and chronic disease biomarkers. We hypothesized that plasma and urinary concentration of green tea catechins are associated with cardiovascular disease and diabetes biomarkers. First void urine and fasting plasma samples were collected from 57 generally healthy females aged 38 to 73 years (mean, 52 ± 8 years) recruited in Himeji, Japan. The concentrations of plasma and urinary green tea catechins were determined by liquid chromatography coupled with mass tandem spectrometer. Low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, glucose, insulin, glycated hemoglobin, and C-reactive protein in plasma/serum samples were analyzed by a commercial diagnostic laboratory. Statistical associations were assessed using Spearman correlation coefficients. The results showed weak associations between plasma total catechin and triglyceride (r = -0.30) and LDL cholesterol (r = -0.28), whereas plasma (-)-epigallocatechin-3-gallate, (-)-epigallocatechin, (-)-epicatechin-3-gallate, and (-)-epicatechin exhibited weak to moderate associations with triglyceride or LDL cholesterol, but little associations with HDL cholesterol, body fat, and body mass index were evident. Urinary total catechin was weakly associated with triglyceride (r = -0.19) and LDL cholesterol (r = -0.15), whereas urinary (-)-epigallocatechin-3-gallate (r = -0.33), (-)-epigallocatechin (r = -0.23), and (-)-epicatechin-3-gallate (r = -0.33) had weak to moderate correlations with triglyceride and similarly with body fat and body mass index. Both plasma (r = -0.24) and urinary (r = -0.24) total catechin, as well as individual catechins, were weakly associated with glycated hemoglobin. Plasma total and individual catechins were weakly to moderately associated with C-reactive protein, but not the case for urinary catechins. In conclusion, we found weak to moderate associations between plasma and urinary green tea catechin concentrations and plasma biomarkers of cardiovascular disease and diabetes. Copyright © 2016 Elsevier Inc. All rights reserved.

Investigate the Binding of Catechins to Trypsin Using Docking and Molecular Dynamics Simulation

PubMed Central

Cui, Fengchao; Yang, Kecheng; Li, Yunqi

2015-01-01

To explore the inhibitory mechanism of catechins for digestive enzymes, we investigated the binding mode of catechins to a typical digestive enzyme-trypsin and analyzed the structure-activity relationship of catechins, using an integration of molecular docking, molecular dynamics simulation and binding free energy calculation. We found that catechins with different structures bound to a conservative pocket S1 of trypsin, which is comprised of residues 189–195, 214–220 and 225–228. In the trypsin-catechin complexes, Asp189 by forming strong hydrogen bonding, and Gln192, Trp215 and Gly216 through hydrophobic interactions, all significantly contribute to the binding of catechins. The number and the position of hydroxyl and aromatic groups, the structure of stereoisomers, and the orientation of catechins in the binding pocket S1 of trypsin all affect the binding affinity. The binding affinity is in the order of Epigallocatechin gallate (EGCG) > Epicatechin gallate (ECG) > Epicatechin (EC) > Epigallocatechin (EGC), and 2R-3R EGCG shows the strongest binding affinity out of other stereoisomers. Meanwhile, the synergic conformational changes of residues and catechins were also analyzed. These findings will be helpful in understanding the knowledge of interactions between catechins and trypsin and referable for the design of novel polyphenol based functional food and nutriceutical formulas. PMID:25938485

HRMS Profile of a Hazelnut Skin Proanthocyanidin-rich Fraction with Antioxidant and Anti-Candida albicans Activities.

PubMed

Piccinelli, Anna Lisa; Pagano, Imma; Esposito, Tiziana; Mencherini, Teresa; Porta, Amalia; Petrone, Anna Maria; Gazzerro, Patrizia; Picerno, Patrizia; Sansone, Francesca; Rastrelli, Luca; Aquino, Rita Patrizia

2016-01-27

Roasted hazelnut skins (RHS) represent a byproduct of kernel industrial processing. In this research, a RHS extract (RHS-M) and its fraction RHS-M-F3 enriched in proanthocyanidins (PAs), with antioxidant activity, were characterized in terms of total phenolic compound and PA contents. RHS-M and RHS-M-F3 showed antifungal properties against Candida albicans SC5314 (MIC2 = 3.00 and 0.10 μg/mL and MIC0 = 5.00 and 0.50 μg/mL, respectively), determined by the microbroth dilution method and Candida albicans morphological analysis. No cytotoxic effect on HEKa and HDFa cell lines was exhibited by RHS-M and RHS-M-F3. The metabolite profiling of RHS-M and RHS-M-F3 was performed by thiolysis followed by HPLC-UV-HRMS analysis and a combination of HRMS-FIA and HPLC-HRMS(n). Extract and fraction contain oligomeric PAs (mDP of 7.3 and 6.0, respectively, and DP up to 10) mainly constituted by B-type oligomers of (epi)-catechin. Also, (epi)-gallocatechin and gallate derivatives were identified as monomer units, and A-type PAs were detected as minor compounds.

In vitro antioxidant activity of phenolic-enriched extracts from Zhangping Narcissus tea cake and their inhibition on growth and metastatic capacity of 4T1 murine breast cancer cells* #

PubMed Central

Ying, Le; Kong, De-dong; Gao, Yuan-yuan; Yan, Feng; Wang, Yue-fei; Xu, Ping

2018-01-01

Phenolics, as the main bioactive compounds in tea, have been suggested to have potential in the prevention of various human diseases. However, little is known about phenolics and their bioactivity in Zhangping Narcissue tea cake which is considered the most special kind of oolong tea. To unveil its bioactivity, three phenolic-enriched extracts were obtained from Zhangping Narcissue tea cake using ethyl acetate, n-butanol, and water. Their main chemical compositions and in vitro bioactivity were analyzed by high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The ethyl acetate fraction (ZEF) consisted of higher content of phenolics, flavonoids, procyanidins, and catechin monomers (including epigallocatechin gallate (EGCG), epicatechin gallate (ECG), and gallocatechin gallate (GCG)) than n-butanol fraction (ZBF) and water fraction (ZWF). ZEF exhibited the strongest antioxidant capacity in vitro due to its abundant bioactive compounds. This was validated by Pearson correlation and hierarchical clustering analyses. ZEF also showed a remarkable inhibition on the growth, migration, and invasion of 4T1 murine breast cancer cells. PMID:29504313

Comparison of effects of green tea catechins on apicomplexan hexose transporters and mammalian orthologues

PubMed Central

Slavic, Ksenija; Derbyshire, Elvira T.; Naftalin, Richard J.; Krishna, Sanjeev; Staines, Henry M.

2009-01-01

Here we have investigated the inhibitory properties of green tea catechins on the Plasmodium falciparum hexose transporter (PfHT), the Babesia bovis hexose transporter 1 (BboHT1) and the mammalian facilitative glucose transporters, GLUT1 and GLUT5, expressed in Xenopus laevis oocytes. (−)-Epicatechin-gallate (ECG) and (−)-epigallocatechin-gallate (EGCG) inhibited d-glucose transport by GLUT1 and PfHT, and d-fructose transport by GLUT5, with apparent Ki values between 45 and 117 μM. BboHT1 was more potently inhibited by the ungallated catechins (−)-epicatechin (EC) and (−)-epigallocatechin (EGC), with apparent Ki values of 108 and 168 μM, respectively. Site-directed mutagenesis experiments provided little further support for previously reported models of catechin binding to hexose transporters. Furthermore, P. falciparum growth inhibition by catechins was not affected by the external d-glucose concentration. Our results provide new data on the inhibitory action of catechins against sugar transporters but were unable to elucidate the antimalarial mechanism of action of these agents. PMID:19577593

ORAC and DPPH assay comparison to assess antioxidant capacity of tea infusions: relationship between total polyphenol and individual catechin content.

PubMed

Roy, Molay K; Koide, Motoki; Rao, Theertham P; Okubo, Tsutomu; Ogasawara, Yutaka; Juneja, Lekh R

2010-03-01

Commercially available tea infusions are the major source of catechins for preparing bottled tea beverages and tea supplements available in the market today. In the present study, we analyzed five tea infusions to measure the total antioxidant capacity (TAC) by oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity (DRSC) assays, total polyphenol content by the colorimetric method and individual catechin content by high-performance liquid chromatography. Four major tea catechins were also analyzed for their TAC to reveal differential antioxidant behavior of the tea infusions, resulting in the ORAC and DRSC methods. The correlation coefficients between DRSC and the total polyphenol or total catechin content of the tea infusions were 1.0 and 0.99. However, the values fall to 0.73 and 0.69, respectively, while the ORAC activity was correlated with total polyphenol and total catechin content. Determining the TAC of individual tea catechins showed that ORAC of epicatechin was seven-fold higher than that of epigallocatechin gallate; on the contrary, epigallocatechin gallate showed significantly (P < 0.05) stronger DRSC activity than epicatechin. By evaluating the structure-activity relationship, this study further revealed that OH substitution at the 3' position in pyrogallol moieties contributes to the lower ORAC value of epigallocatechin and epigallocatechin gallate comparing with their non-3'-OH counterparts, such as epicatechin and epicatechin gallate, respectively. Also, numbers of OH substitutions were poorly correlated with the observed ORAC value unlike the DRSC. Overall, results of this study enabled us to hypothesize that substances having a lower TAC value in the ORAC assay compared with that in DPPH assays may pertain to a pro-oxidant effect by generating reactive oxygen species in an aqueous buffer, at a physiological pH. We also propose that substances exhibiting lower TAC value in the ORAC assay compared with that in the DPPH assay are powerful pro-oxidants compared with the substances showing a higher TAC value in the ORAC assay than that in the DPPH assay.

Biomimetic Modeling of Copper Complexes: A Study of Enantioselective Catalytic Oxidation on D-(+)-Catechin and L-( − )-Epicatechin with Copper Complexes

PubMed Central

Mutti, Francesco G.; Pievo, Roberta; Sgobba, Maila; Gullotti, Michele; Santagostini, Laura

2008-01-01

The biomimetic catalytic oxidations of the dinuclear and trinuclear copper(II) complexes versus two catechols, namely, D-(+)-catechin and L-( − )-epicatechin to give the corresponding quinones are reported. The unstable quinones were trapped by the nucleophilic reagent, 3-methyl-2-benzothiazolinone hydrazone (MBTH), and have been calculated the molar absorptivities of the different quinones. The catalytic efficiency is moderate, as inferred by kinetic constants, but the complexes exhibit significant enantio-differentiating ability towards the catechols, albeit for the dinuclear complexes, this enantio-differentiating ability is lower. In all cases, the preferred enantiomeric substrate is D-(+)-catechin to respect the other catechol, because of the spatial disposition of this substrate. PMID:18825268

Preventive effects of C-2 epimeric isomers of tea catechins on mouse type I allergy.

PubMed

Yoshino, Kyoji; Miyase, Toshio; Sano, Mitsuaki

2010-01-01

The preventive effects of C-2 epimeric isomers of (-)-epigallocatechin-3-O-gallate (EGCG) and the O-methylated derivative, (-)-epigallocatechin-3-O-(3-O-methyl)gallate (EGCG3''Me), against ovalbumin-induced type I allergy in male mice were investigated. EGCG and EGCG3''Me exhibited strong antiallergic effects by oral administration at doses of 25 and 50 mg/kg body weight. The antiallergic effects of their C-2 epimers, (-)-gallocatechin-3-O-gallate and (-)-gallocatechin-3-O-(3-O-methyl)gallate (GCG3''Me), on mouse type I allergy were almost equivalent to and/or as strong as those of the corresponding original catechins, respectively. Oral administration of these compounds at a dose of 50 mg/kg body weight tended to suppress the increases in interleukin-4 levels in the abdominal walls of allergic mice and immunoglobulin E levels in the serum of allergic mice. In particular, the administration of GCG3''Me exhibited significant effects on the production and/or release of these parameters stimulating type 2 T helper cells and mast cells in the type I allergic process. These results indicated that C-2 epimerization of tea catechins, which are produced during heat processing at high temperatures, would not be disadvantageous for preventive effects on type I allergy.

Fluorescent detection of (-)-epicatechin in microsamples from cacao seeds and cocoa products: Comparison with Folin-Ciocalteu method.

PubMed

Ramirez-Sanchez, Israel; Maya, Lisandro; Ceballos, Guillermo; Villarreal, Francisco

2010-12-01

Polyphenolic compounds of the flavanoid family are abundantly present in cacao seed and its cocoa products. Results from studies using cocoa products indicate beneficial effects of flavanols on cardiovascular endpoints. Evidence indicates that (-)-epicatechin is the main cacao flavanol associated with cardiovascular effects, so the accurate quantification of its content in cacao seeds or cocoa products is important. Common methods for the quantification of phenolic content in cocoa products are based on the reaction of phenols with colorimetric reagents such as the Folin-Ciocalteu (FC) In this study, we compared the FC method of phenolic determinations using 2 different standards (gallic acid and (-)-epicatechin) to construct calibration curves. We compare these results with those obtained from a simple fluorometric method (Ex(280)/Em(320) nm) used to determine catechin/(-)-epicatechin content in samples of cacao seeds and cocoa products. Values obtained from the FC method determination of polyphenols yield an overestimation of phenol (flavonoid) content when gallic acid is used as standard. Moreover, the epicatechin is a more reliable standard because of its abundance in cacao seeds and cocoa products. The use of fluorometric spectra yields a simple and highly quantitative means for a more precise and rapid quantification of cacao catechins. Fluorometric values are essentially in agreement with those reported using more cumbersome methods. In conclusion, the use of fluorescence emission spectra is a quick, practical and suitable means to quantifying catechins in cacao seeds and cocoa products.

Flavanols and methylxanthines in commercially available dark chocolate: a study of the correlation with nonfat cocoa solids.

PubMed

Langer, Swen; Marshall, Lisa J; Day, Andrea J; Morgan, Michael R A

2011-08-10

Intake of flavanols, a subgroup of dietary polyphenols present in many fruits and vegetables, may be associated with health benefits, particularly with reducing the risk of coronary diseases. Cocoa and chocolate products are rich in flavanol monomers, oligomers, and polymers (procyanidins). This study used normal phase HPLC to detect, identify, and quantify epicatechin, catechin, total monomers, procyanidin oligomers and polymers in 14 commercially available chocolate bars. In addition, methylxanthines (theobromine and caffeine) were also quantified. Nonfat cocoa solids (NFCS) were determined both gravimetrically and by calculation from theobromine contents. The flavanol levels of 12 commonly consumed brands of dark chocolate have been quantified and correlated with % theobromine and % NFCS. Epicatechin comprised the largest fraction of total chocolate flavonoids, with the remainder being catechin and procyanidins. Calculated NFCS did not reflect epicatechin (R(2) = 0.41) or total flavanol contents (R(2) = 0.49). Epicatechin (R(2) = 0.96) was a reliable marker of total flavanols, catechin (R(2) = 0.67) to a lesser extent. All dark chocolate tested contained higher levels of total flavanols (93.5-651.1 mg of epicatechin equiv/100 g of product) than a milk or a white "chocolate" (40.6 and 0.0 mg of epicatechin equiv/100 g, respectively). The amount and integrity of procyanidins often suffer in the manufacturing of chocolate, chiefly due to oxidation and alkalinization. In this study, the labeled cocoa content of the chocolate did not always reflect analyzed levels of flavonoids. Increasingly, high % NFCS is being used commercially to reflect chocolate quality. If the flavanol content of chocolate is accepted to be a key determinant of health benefits, then continued monitoring of flavanol levels in commercially available chocolate products may be essential for consumer assurance.

Survey of commercially available chocolate- and cocoa-containing products in the United States. 2. Comparison of flavan-3-ol content with nonfat cocoa solids, total polyphenols, and percent cacao.

PubMed

Miller, Kenneth B; Hurst, W Jeffrey; Flannigan, Nancy; Ou, Boxin; Lee, C Y; Smith, Nancy; Stuart, David A

2009-10-14

A survey of a broad range of chocolate- and cocoa-containing products marketed in the United States was conducted to provide a more detailed analysis of flavan-3-ol monomers, oligomers, and polymers, which can be grouped into a class of compounds called procyanidins. Samples consisted of the three or four top-selling products within the following six categories: natural cocoa powder, unsweetened baking chocolate, dark chocolate, semisweet baking chips, milk chocolate, and chocolate syrup. Composite samples were characterized for percent fat (% fat), percent nonfat cocoa solids (% NFCS), antioxidant level by ORAC, total polyphenols, epicatechin, catechin, total monomers, and flavan-3-ol oligomers and polymers (procyanidins). On a gram weight basis epicatechin and catechin content of the products follow in decreasing order: cocoa powder > baking chocolate > dark chocolate = baking chips > milk chocolate > chocolate syrup. Analysis of the monomer and oligomer profiles within product categories shows there are two types of profiles: (1) products that have high monomers with decreasing levels of oligomers and (2) products in which the level of dimers is equal to or greater than the monomers. Results show a strong correlation (R(2) = 0.834) of epicatechin to the level of % NFCS and also very good correlations for N = 2-5 oligomers to % NFCS. A weaker correlation was observed for catechin to % NFCS (R(2) = 0.680). Other analyses show a similar high degree of correlation with epicatechin and N = 2-5 oligomers to total polyphenols, with catechin being less well correlated to total polyphenols. A lesser but still good correlation exists between the calculated percent cacao (calcd % cacao) content, a proxy for percent cacao, and these same flavanol measures, with catechin again showing a lesser degree of correlation to calcd % cacao. Principal component analysis (PCA) shows that the products group discretely into five classes: (1) cocoa powder, (2) baking chocolate, (3) dark chocolate and semisweet chips, (4) milk chocolates, and (5) syrup. PCA also shows that most factors group closely together including the antioxidant activity, total polyphenols, and the flavan-3-ol measures with the exception of catechin and % fat in the product, which group separately. Because catechin distribution appears to be different from the other flavan-3-ol measures, an analysis of the epicatechin to catechin ratio was done, indicating there is a >5-fold variation in this measure across the products studied. The cocoa-containing products tested range from cocoa powder with 227.34 +/- 17.23 mg of procyanidins per serving to 25.75 +/- 9.91 mg of procyanidins per serving for chocolate syrup. These results are discussed with respect to other studies on commercial products, the bioavailability of the flavanols, and the possible role of processing on the amount of catechin in products.

Conformational isomerism of phenolic procyanidins: preferred conformations in organic solvents and water

Treesearch

Tsutomu Hatano; Richard W. Hemingway

1997-01-01

NMR studies of catechin-{4α→8)-epicatechin (I) and catechin-{4α→8)-catechin (2) provided complete assignment of the proton and carbon resonances for both the more extended and compact conformers in the free phenolic form. When 1 is in organic solvents, the more extended rotamer is preferred over the more compact rotamer (10:7), but...

In situ analysis and structural elucidation of sainfoin (Onobrychis viciifolia) tannins for high-throughput germplasm screening.

PubMed

Gea, An; Stringano, Elisabetta; Brown, Ron H; Mueller-Harvey, Irene

2011-01-26

A rapid thiolytic degradation and cleanup procedure was developed for analyzing tannins directly in chlorophyll-containing sainfoin ( Onobrychis viciifolia ) plants. The technique proved suitable for complex tannin mixtures containing catechin, epicatechin, gallocatechin, and epigallocatechin flavan-3-ol units. The reaction time was standardized at 60 min to minimize the loss of structural information as a result of epimerization and degradation of terminal flavan-3-ol units. The results were evaluated by separate analysis of extractable and unextractable tannins, which accounted for 63.6-113.7% of the in situ plant tannins. It is of note that 70% aqueous acetone extracted tannins with a lower mean degree of polymerization (mDP) than was found for tannins analyzed in situ. Extractable tannins had between 4 and 29 lower mDP values. The method was validated by comparing results from individual and mixed sample sets. The tannin composition of different sainfoin accessions covered a range of mDP values from 16 to 83, procyanidin/prodelphinidin (PC/PD) ratios from 19.2/80.8 to 45.6/54.4, and cis/trans ratios from 74.1/25.9 to 88.0/12.0. This is the first high-throughput screening method that is suitable for analyzing condensed tannin contents and structural composition directly in green plant tissue.

Effect of green tea catechins and hydrolyzable tannins on benzo[a]pyrene-induced DNA adducts and structure-activity relationship.

PubMed

Cao, Pengxiao; Cai, Jian; Gupta, Ramesh C

2010-04-19

Green tea catechins and hydrolyzable tannins are gaining increasing attention as chemopreventive agents. However, their mechanism of action is poorly understood. We investigated the effects of four green tea catechins and two hydrolyzable tannins on microsome-induced benzo[a]pyrene (BP)-DNA adducts and the possible structure-activity relationship. BP (1 microM) was incubated with rat liver microsomes and DNA in the presence of the test compound (1-200 microM) or vehicle. The purified DNA was analyzed by (32)P-postlabeling. The inhibitory activity of the catechins was in the following descending order: epigallocatechin gallate (IC(50) = 16 microM) > epicatechin gallate (24 microM) > epigallocatechin (146 microM) > epicatechin (462 microM), suggesting a correlation between the number of adjacent aromatic hydroxyl groups in the molecular structure and their potencies. Tannic acid (IC(50) = 4 microM) and pentagalloglucose (IC(50) = 26 microM) elicited as much DNA adduct inhibitory activity as the catechins or higher presumably due to the presence of more functional hydroxyl groups. To determine if the activity of these compounds was due to direct interaction of phenolic groups with electrophilic metabolite(s) of BP, DNA was incubated with anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) (0.5 microM) in the presence of test compounds (200 microM) or vehicle. Significant inhibition of DNA adduct formation was found (tannic acid > pentagalloglucose > epigallocatechin gallate > epicatechin gallate). This notion was confirmed by analysis of the reaction products of anti-BPDE with the catechins and pentagalloglucose by electrospray ionization mass spectrometry and liquid chromatography-mass spectrometry. In conclusion, our data demonstrate that green tea catechins and the hydrolyzable tannins are highly effective in inhibiting BP-DNA adduct formation at least, in part, due to direct interaction of adjacent hydroxyl groups in their structures and that the activity is higher with an increasing number of functional hydroxyl groups.

Effect of Green Tea Catechins and Hydrolyzable Tannins on Benzo[a]pyrene-Induced DNA Adducts and Structure–Activity Relationship

PubMed Central

Cao, Pengxiao; Cai, Jian; Gupta, Ramesh C.

2016-01-01

Green tea catechins and hydrolyzable tannins are gaining increasing attention as chemopreventive agents. However, their mechanism of action is poorly understood. We investigated the effects of four green tea catechins and two hydrolyzable tannins on microsome-induced benzo[a]pyrene (BP)–DNA adducts and the possible structure–activity relationship. BP (1 μM) was incubated with rat liver microsomes and DNA in the presence of the test compound (1–200 μM) or vehicle. The purified DNA was analyzed by 32P-postlabeling. The inhibitory activity of the catechins was in the following descending order: epigallocatechin gallate (IC50 = 16 μM) > epicatechin gallate (24 μM) > epigallocatechin (146 μM) > epicatechin (462 μM), suggesting a correlation between the number of adjacent aromatic hydroxyl groups in the molecular structure and their potencies. Tannic acid (IC50 = 4 μM) and pentagalloglucose (IC50 = 26 μM) elicited as much DNA adduct inhibitory activity as the catechins or higher presumably due to the presence of more functional hydroxyl groups. To determine if the activity of these compounds was due to direct interaction of phenolic groups with electrophilic metabolite(s) of BP, DNA was incubated with anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) (0.5 μM) in the presence of test compounds (200 μM) or vehicle. Significant inhibition of DNA adduct formation was found (tannic acid > pentagalloglucose > epigallocatechin gallate > epicatechin gallate). This notion was confirmed by analysis of the reaction products of anti-BPDE with the catechins and pentagalloglucose by electrospray ionization mass spectrometry and liquid chromatography–mass spectrometry. In conclusion, our data demonstrate that green tea catechins and the hydrolyzable tannins are highly effective in inhibiting BP–DNA adduct formation at least, in part, due to direct interaction of adjacent hydroxyl groups in their structures and that the activity is higher with an increasing number of functional hydroxyl groups. PMID:20218540

Quantitative analysis of catechins in Saraca asoca and correlation with antimicrobial activity

PubMed Central

Shirolkar, Amey; Gahlaut, Anjum; Chhillar, Anil K.; Dabur, Rajesh

2013-01-01

Herbal medicines are highly complex and have unknown mechanisms in diseases treatment. Saraca asoca (Roxb.), De. Wild has been recommended to treat gynecological disorders and used in several commercial polyherbal formulations. In present study, efforts have been made to explore antimicrobial activity and its co-relation with the distributions of catechins in the organs of S. asoca using targeted MS/MS. Eight extracts (cold and hot water) from four different organs of S. asoca and two drugs were prepared and antimicrobial activity was assessed by microbroth dilution assay. Quantitative and qualitative analysis of catechins in crude extracts was done by using targeted and auto-MS/MS and correlated with antimicrobial activity. (+)-Catechin and (+)-epicatechin and their biosynthesis related compound were found to be up-regulated in regenerated bark and leaves extracts. (−)-Epigallocatechin was found to be significantly higher in bark water extract as compared to others but showed low antimicrobial activity. Result showed down-regulation of (−)-epigallocatechin and up-regulation of (+)-catechin and (+)-epicatechin in the regenerated bark and leaves of S. asoca. It might be the contributing factor in the antimicrobial activity of regenerated bark and leaves of the plant. The concentration of (+)-epicatechin in processed drugs (Ashokarishta) from Baidyanath was found to be seven times higher than that of Dabur Pvt. Ltd., but no antimicrobial activity was observed, indicating the variations among the plant based drugs. This will be helpful in rational use of S. asoca parts. Furthermore, the analytical method developed is sensitive, repeatable and reliable; therefore, it is suitable for quality control of herbal drugs. PMID:29403849

Common tea formulations modulate in vitro digestive recovery of green tea catechins.

PubMed

Green, Rodney J; Murphy, Angus S; Schulz, Burkhard; Watkins, Bruce A; Ferruzzi, Mario G

2007-09-01

Epidemiological evidence suggests a role for tea catechins in reduction of chronic disease risk. However, stability of catechins under digestive conditions is poorly understood. The objective of this study was to characterize the effect of common food additives on digestive recovery of tea catechins. Green tea water extracts were formulated in beverages providing 4.5, 18, 23, and 3.5 mg per 100 mL epicatechin (EC), epigallocatechin (EGC), epigallocatechin-gallate (EGCG), and epicatechin-gallate (ECG), respectively. Common commercial beverage additives; citric acid (CA), BHT, EDTA, ascorbic acid (AA), milk (bovine, soy, and rice), and citrus juice (orange, grapefruit, lemon, and lime) were formulated into finished tea beverages at incremental dosages. Samples were then subjected to in vitro digestion simulating gastric and small intestinal conditions with pre- and post-digestion catechin profiles assessed by HPLC. Catechin stability in green tea was poor with <20% total catechins remaining post-digestion. EGC and EGCG were most sensitive with less, not double equals 10% recovery. Teas formulated with 50% bovine, soy, and rice milk increased total catechin recovery significantly to 52, 55, and 69% respectively. Including 30 mg AA in 250 mL of tea beverage significantly (p<0.05) increased catechin recovery of EGC, EGCG, EC, and ECG to 74, 54, 82, and 45% respectively. Juice preparation resulted in the highest recovery of any formulation for EGC (81-98%), EGCG (56-76%), EC (86-95%), and ECG (30-55%). These data provide evidence that tea consumption practices and formulation factors likely impact catechin digestive recovery and may result in diverse physiological profiles.

Monoamine oxidase B (MAO-B) inhibition by active principles from Uncaria rhynchophylla.

PubMed

Hou, Wen-Chi; Lin, Rong-Dih; Chen, Cheng-Tang; Lee, Mei-Hsien

2005-08-22

Attenuation of monoamine oxidase B (MAO-B) activity may provide protection against oxidative neurodegeneration. For this reason, inhibition of MAO-B activity is used as part of the treatment of Parkinson's and Alzheimer's patients. The hook of Uncaria rhynchophylla (Miq.) Jacks. (Rubiaceae) is a traditional Chinese herbal drug that is generally used to treat convulsive disorders. In this study, the fractionation and purification of Uncaria rhynchophylla extracts using a bioguided assay isolated two known compounds, (+)-catechin and (-)-epicatechin. The compounds inhibited MAO-B, as measured by an assay of rat brain MAO-B separated by electrophoresis on a 7.5% native polyacrylamide gel. The IC(50) values of (+)-catechin and (-)-epicatechin were 88.6 and 58.9 microM, respectively, and inhibition occurred in a dose-dependent manner, as measured by the fluorescence method. The Lineweaver-Burk plot revealed K(i) values for (+)-catechin and (-)-epicatechin of 74 and 21 microM, respectively. This suggests that these two compounds, isolated here for the first time from Uncaria rhynchophylla, might be able to protect against neurodegeneration in vitro, and, therefore, the molecular mechanism deserves further study. This finding may also increase interest in the health benefits of Uncaria rhynchophylla.

Effect of emulsification on the skin permeation and UV protection of catechin.

PubMed

Yoshino, Sachie; Mitoma, Tomoaki; Tsuruta, Keiko; Todo, Hiroaki; Sugibayashi, Kenji

2014-06-01

An anti-aging effect may be obtained by skin application of tea catechins (Camellia sinensis) since they have high ultraviolet (UV)-protection activity. In this study, the skin permeation of catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECg) and epigallocatechin gallate (EGCg) was determined and compared, and the effect of emulsification on the skin permeation of C was measured. The UV-protective effect of C was also determined. The in vitro skin permeability of each catechin derivative was determined using side-by-side diffusion of cells. The UV-protective effect of C was determined by applying different concentrations of C to the solution or emulsion on a three-dimensional cultured human skin model or normal human epidermal keratinocytes with UV-irradiation. ECg and EGCg with gallate groups showed lower skin permeability than C, EC and EGC without gallate groups, suggesting that the skin permeability of catechin derivatives may be dependent on the existence of a gallate group. Interestingly, the skin permeation of C was increased by an o/w emulsification. In addition, the C emulsion showed a significantly higher UV-protective effect by C than that with its aqueous solution. These results suggest that the o/w emulsion of catechin derivatives is probably useful as a cosmetic formulation with anti-aging efficacy.

Theaflavins in black tea and catechins in green tea are equally effective antioxidants.

PubMed

Leung, L K; Su, Y; Chen, R; Zhang, Z; Huang, Y; Chen, Z Y

2001-09-01

Green tea catechins, including (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG), are oxidized and dimerized during the manufacture of black tea and oolong tea to form orange-red pigments, theaflavins (TF), a mixture of theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B) and theaflavin-3,3'-digallate (TF3). The present study was designed to compare the antioxidant activities of individual TF with that of each catechin using human LDL oxidation as a model. All catechins and TF tested inhibited Cu(+2)-mediated LDL oxidation. Analysis of the thiobarbituric acid-reactive substances (TBARS) and conjugated dienes produced during LDL oxidation revealed that the antioxidant activity was in the order: TF3 > ECG > EGCG > or = TF2B > or = TF2A > TF1 > or = EC > EGC. Four TF derivatives also demonstrated a dose-dependent antioxidant activity in Cu(+2)-mediated LDL oxidation at concentrations of 5-40 micromol/L. These results demonstrate that the TF present in black tea possess at least the same antioxidant potency as catechins present in green tea, and that the conversion of catechins to TF during fermentation in making black tea does not alter significantly their free radical-scavenging activity.

Comparison of the nutrient and chemical contents of traditional Korean Chungtaejeon and green teas.

PubMed

Park, Yong-Seo; Lee, Mi-Kyung; Heo, Buk-Gu; Ham, Kyung-Sik; Kang, Seong-Gook; Cho, Ja-Yong; Gorinstein, Shela

2010-06-01

This study was conducted in order to compare the nutrient and chemical contents of two Korean teas: traditional Chungtaejeon tea (CTJ) with that of green tea (GT). Main bioactive compounds and the antioxidant activities using four radical scavenging assays (ABTS, CUPRAC, FRAP and DPPH) in methanol and acetone extracts of both teas were determined. It was found that the contents of vitamin C, amino acids and total nitrogen in CTJ were lower than that of GT (p < 0.05). Caffeine, reducing sugar and chlorophyll contents in CTJ were similar to GT. Catechin (C), epicatechin (EC), and epigallocatechin (EGC) contents were lower in CTJ than in green tea (p < 0.05), but gallocatechin (GC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG) and catechin gallate (CG) showed no significant differences between CTJ and GT (p >/= 0.05). The contents of polyphenols, flavonoids, flavanols and tannins in CTJ methanol were 229.30 +/- 11.3 mg GAE/g dry weight (DW), 15.24 +/- 0.8 mg CE/g DW, 109.10 +/- 5.1 mg CE/g DW and 25.68 +/- 1.2 mg CE/g DW, respectively, and significantly higher than in acetone extracts (p < 0.05). Flavonoids (quercetin and kaempferol) were higher in GT than in CTJ and myricetin was higher in CTJ (p < 0.05). Threonine and aspartic acid was lower, and glutamic acid was higher in CTJ compared with GT (p < 0.05). Free amino acid content in CTJ and GT showed no significant difference. Potassium and magnesium in CTJ were lower compared to GT, but no significant difference was found for iron, manganese and calcium. Also, the level of the antioxidant activity by all four used assays was significantly higher in CTJ and in methanol was higher than in acetone extracts (p < 0.05). In conclusion, traditional fermented Korean tea Chungtaejeon contains high quantities of bioactive compounds and possesses high antioxidant activity. The contents of the bioactive compounds and the levels of antioxidant activities are significantly higher in methanol than in acetone extracts. 3-D fluorescence and FTIR- spectroscopy showed slight differences between the two investigated tea samples and can be used as additional tools for identification of polyphenols. Both studied teas can be recommended as a source of bioactive compounds.

Loblolly pine bark flavanoids

Treesearch

J.J. Karchesy; R.W. Hemingway

1980-01-01

The inner bark of Pinus taeda L. contains (+)-catechin, the procyanidin 8.1 (a C-4 to C-8 linked (-)-epicatechin to (+)-catechin dimer), and three polymeric procyanidins that have distinctly different solubility and chromatographic properties. An ethyl acetate soluble polymer (0.20% of bark, Mn = 1200) was purified by chromatography on LH-20 Sephadex. A water-soluble...

Epicatechin and catechin modulate endothelial activation induced by platelets of patients with peripheral artery disease.

PubMed

Carnevale, R; Loffredo, L; Nocella, C; Bartimoccia, S; Bucci, T; De Falco, E; Peruzzi, M; Chimenti, I; Biondi-Zoccai, G; Pignatelli, P; Violi, F; Frati, G

2014-01-01

Platelet activation contributes to the alteration of endothelial function, a critical initial step in atherogenesis through the production and release of prooxidant mediators. There is uncertainty about the precise role of polyphenols in interaction between platelets and endothelial cells (ECs). We aimed to investigate whether polyphenols are able to reduce endothelial activation induced by activated platelets. First, we compared platelet activation and flow-mediated dilation (FMD) in 10 healthy subjects (HS) and 10 patients with peripheral artery disease (PAD). Then, we evaluated the effect of epicatechin plus catechin on platelet-HUVEC interaction by measuring soluble cell adhesion molecules (CAMs), NOx production, and eNOS phosphorylation (p-eNOS) in HUVEC. Compared to HS, PAD patients had enhanced platelet activation. Conversely, PAD patients had lower FMD than HS. Supernatant of activated platelets from PAD patients induced an increase of sCAMs release and a decrease of p-eNOS and nitric oxide (NO) bioavailability compared to unstimulated HUVEC. Coincubation of HUVEC, with supernatant of PAD platelets patients, pretreated with a scalar dose of the polyphenols, resulted in a decrease of sCAMs release and in an increase of p-eNOS and NO bioavailability. This study demonstrates that epicatechin plus catechin reduces endothelial activation induced by activated platelets.

A combination of (+)-catechin and (-)-epicatechin underlies the in vitro adipogenic action of Labrador tea (Rhododendron groenlandicum), an antidiabetic medicinal plant of the Eastern James Bay Cree pharmacopeia.

PubMed

Eid, Hoda M; Ouchfoun, Meriem; Saleem, Ammar; Guerrero-Analco, Jose A; Walshe-Roussel, Brendan; Musallam, Lina; Rapinski, Michel; Cuerrier, Alain; Martineau, Louis C; Arnason, John T; Haddad, Pierre S

2016-02-03

Rhododendron groenlandicum (Oeder) Kron & Judd (Labrador tea) was identified as an antidiabetic plant through an ethnobotanical study carried out with the close collaboration of Cree nations of northern Quebec in Canada. In a previous study the plant showed glitazone-like activity in a 3T3-L1 adipogenesis bioassay. The current study sought to identify the active compounds responsible for this potential antidiabetic activity using bioassay guided fractionation based upon an in vitro assay that measures the increase of triglycerides content in 3T3-L1 adipocyte. Isolation and identification of the crude extract's active constituents was carried out. The 80% ethanol extract was fractionated using silica gel column chromatography. Preparative HPLC was then used to isolate the constituents. The identity of the isolated compounds was confirmed by UV and mass spectrometry. Nine chemically distinct fractions were obtained and the adipogenic activity was found in fraction 5 (RGE-5). Quercetins, (+)-catechin and (-)-epicatechin were detected and isolated from this fraction. While (+)-catechin and (-)-epicatechin stimulated adipogenesis (238±26% and 187±21% relative to vehicle control respectively) at concentrations equivalent to their concentrations in the active fraction RGE-5, none afforded biological activity similar to RGE-5 or the plant's crude extract when used alone. When cells were incubated with a mixture of the two compounds, the adipogenic activity was close to that of the crude extract (280.7±27.8 vs 311± 30%). Results demonstrate that the mixture of (+)-catechin and (-)-epicatechin is responsible for the adipogenic activity of Labrador tea. This brings further evidence for the antidiabetic potential of R. groenlandicum and provides new opportunities to profile active principles in biological fluids or in traditional preparations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Analyses of polyphenols in cacao liquor, cocoa, and chocolate by normal-phase and reversed-phase HPLC.

PubMed

Natsume, M; Osakabe, N; Yamagishi, M; Takizawa, T; Nakamura, T; Miyatake, H; Hatano, T; Yoshida, T

2000-12-01

The antioxidant polyphenols in cacao liquor, a major ingredient of chocolate and cocoa, have been characterized as flavan-3-ols and proanthocyanidin oligomers. In this study, various cacao products were analyzed by normal-phase HPLC, and the profiles and quantities of the polyphenols present, grouped by molecular size (monomers to approximately oligomers), were compared. Individual cacao polyphenols, flavan-3-ols (catechin and epicatechin), and dimeric (procyanidin B2), trimeric (procyanidin C1), and tetrameric (cinnamtannin A2) proanthocyanidins, and galactopyranosyl-ent-(-)-epicatechin (2alpha-->7, 4alpha-->8)-(-)-epicatechin (Gal-EC-EC), were analyzed by reversed-phase HPLC and/or HPLC/MS. The profile of monomers (catechins) and proanthocyanidin in dark chocolate was similar to that of cacao liquor, while the ratio of flavan-3-ols to the total amount of monomeric and oligomeric polyphenols in the case of pure cocoa powder was higher than that in the case of cacao liquor or chocolate.

Functional characterization of proanthocyanidin pathway enzymes from tea and their application for metabolic engineering.

PubMed

Pang, Yongzhen; Abeysinghe, I Sarath B; He, Ji; He, Xianzhi; Huhman, David; Mewan, K Mudith; Sumner, Lloyd W; Yun, Jianfei; Dixon, Richard A

2013-03-01

Tea (Camellia sinensis) is rich in specialized metabolites, especially polyphenolic proanthocyanidins (PAs) and their precursors. To better understand the PA pathway in tea, we generated a complementary DNA library from leaf tissue of the blister blight-resistant tea cultivar TRI2043 and functionally characterized key enzymes responsible for the biosynthesis of PA precursors. Structural genes encoding enzymes involved in the general phenylpropanoid/flavonoid pathway and the PA-specific branch pathway were well represented in the library. Recombinant tea leucoanthocyanidin reductase (CsLAR) expressed in Escherichia coli was active with leucocyanidin as substrate to produce the 2R,3S-trans-flavan-ol (+)-catechin in vitro. Two genes encoding anthocyanidin reductase, CsANR1 and CsANR2, were also expressed in E. coli, and the recombinant proteins exhibited similar kinetic properties. Both converted cyanidin to a mixture of (+)-epicatechin and (-)-catechin, although in different proportions, indicating that both enzymes possess epimerase activity. These epimers were unexpected based on the belief that tea PAs are made from (-)-epicatechin and (+)-catechin. Ectopic expression of CsANR2 or CsLAR led to the accumulation of low levels of PA precursors and their conjugates in Medicago truncatula hairy roots and anthocyanin-overproducing tobacco (Nicotiana tabacum), but levels of oligomeric PAs were very low. Surprisingly, the expression of CsLAR in tobacco overproducing anthocyanin led to the accumulation of higher levels of epicatechin and its glucoside than of catechin, again highlighting the potential importance of epimerization in flavan-3-ol biosynthesis. These data provide a resource for understanding tea PA biosynthesis and tools for the bioengineering of flavanols.

New Drugs for Prevention of Breast Cancer Metastases

DTIC Science & Technology

1999-07-01

the principal anticancer catechin, epigallocatechin gallate ( EGCg ). A 3-way mixture of epicatechin (EC), EGCg and glaucarubolone was more effective...DAPI, 4’,6-diamidino-2-phenylindole; DMSO, dimethyl sulfoxide; EGF, epidermal growth factor; EGCg , epigallocatechin gallate . ABSTRACT A drug...preferentially in HeLa and human and mouse mammary adenocarcinoma by the naturally-occurring catechin of green tea, epigallocatechin gallate ( EGCg ). With

Formulation with ascorbic acid and sucrose modulates catechin bioavailability from green tea

PubMed Central

Peters, Catrina M.; Green, Rodney J.; Janle, Elsa M.; Ferruzzi, Mario G.

2009-01-01

In order to investigate the impact of common food ingredients on catechin absorption, green tea (GT) extract (50 mg) was formulated plain, with sucrose (GT+S), with ascorbic acid (GT+AA) and with sucrose and ascorbic acid (GT+S+AA). Bioavailability and bioaccessibility were assessed in Sprague Dawley rats and an in vitro digestion/Caco-2 cell model respectively. Absorption of epigallocatechin (EGC) and epigallocatechin gallate (EGCG) was significantly (P<0.05) enhanced in GT+S+AA formulations (AUC0-6h= 3237.0 and 181.8 pmol*h/L plasma respectively) relative to GT control (AUC0-6h = 1304.1 and 61.0 pmol*h/L plasma respectively). In vitro digestive recovery was higher for EGC and epicatechin (EC) (∼51-53%) relative to EGCG and epicatechin gallate (ECG) (< 20%) and was modestly enhanced in GT+S and GT+S+AA formulations. Accumulation of EGC, EGCG and ECG by Caco-2 cells was significantly (P<0.05) higher from GT+S+AA compared to other formulations while retention of catechins was enhanced in presence of ascorbic acid. These data suggest that formulation with sucrose and ascorbic acid may improve catechin bioavailability by enhancing bioaccessibility and intestinal uptake from tea. PMID:20161530

Molecular Effects of 13C/DIM in Prostate Cancer

DTIC Science & Technology

2006-04-01

contains several cat- echins including epicatechin, epigallocatechin , epicatechin-3- gallate , and epigallocatechin -3- gallate ( EGCG ). However, EGCG has...indole-3-carbinol (I3C), curcumin, ()-epigallo- catechin-3- gallate ( EGCG ), resveratrol, etc.] have been recognized as cancer chemopreventive agents...Ther 2003; 2:95–103. 15. Chisholm K, Bray BJ, Rosengren RJ. Tamoxifen and epigallocatechin gallate are synergistically cytotoxic to MDA-MB-231 human

Screening Antioxidants Using LC-MS: A Case Study with Cocoa

PubMed Central

Calderón, Angela I.; Wright, Brian J.; Hurst, W. Jeffrey; van Breemen, Richard B.

2009-01-01

Oxidative stress enhances pathological processes contributing to cancer, cardiovascular disease and neurodegenerative diseases, and dietary antioxidants may counteract these deleterious processes. Since rapid methods to evaluate and compare food products for antioxidant benefits are needed, a new assay based on liquid chromatography-mass spectrometry (LC-MS) was developed for the identification and quantitative analysis of antioxidants in complex natural product samples such as food extracts. This assay is based on the comparison of electrospray LC-MS profiles of sample extracts before and after treatment with reactive oxygen species such as hydrogen peroxide or DPPH (2,2-diphenyl-1-picrylhydrazyl radical). Using this assay, methanolic extracts of cocoa powder were analyzed, and procyanidins were found to be the most potent antioxidant species. These species were identified using LC-MS, LC-MS-MS, accurate mass measurement, and comparison with reference standards. Furthermore, LC-MS was used to determine the levels of these species in cocoa samples. Catechin and epicatechin were the most abundant antioxidants followed by their dimers and trimers. The most potent antioxidants in cocoa were trimers and dimers of catechin and epicatechin, such as procyanidin B2, followed by catechin and epicatechin. This new LC-MS assay facilitates the rapid identification and then the determination of the relative antioxidant activities of individual antioxidant species in complex natural product samples and food products such as cocoa. PMID:19489609

Isolation of strawberry anthocyanins using high-speed counter-current chromatography and the copigmentation with catechin or epicatechin by high pressure processing.

PubMed

Zou, Hui; Ma, Yan; Xu, Zhenzhen; Liao, Xiaojun; Chen, Ailiang; Yang, Shuming

2018-05-01

Three anthocyanins were isolated from strawberry extract by high-speed counter-current chromatography, using a biphasic mixture of tert-butyl methyl ether, n-butanol, acetonitrile, water and trifluoroacetic acid (2.5:2.0:2.5:5.0:1.0%). The anthocyanins were identified as pelargonidin-3-rutinoside, cyanidin-3-glucoside and pelargonidin-3-glucoside with purity of 95.6%, 96.2% and 99.3% respectively. Additionally, the copigmentation reaction rates between pelargonidin-3-glucoside and phenolic acids (catechin or epicatechin) at pH 1.5 and 3.6, pressure 0.1 and 500 MPa, and temperature 60 °C were calculated. The absorbance of pelargonidin-3-glucoside at pH 3.6, with high quantity of phenolic acids was significantly increased by high pressure. The complex of pelargonidin-3-glucoside/catechin has a binding energy of 78.64 kJ/mol at pH 3.6, and 39.13 kJ/mol at pH 1.5; pelargonidin-3-glucoside/epicatechin has a binding energy of 75.34 kJ/mol at pH 1.5 and 54.47 kJ/mol at pH 3.6. The hydrogen bond and van der Waals interaction were the main forces contributing to the structures of complex. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metabolic dependence of green tea on plucking positions revisited: a metabolomic study.

PubMed

Lee, Jang-Eun; Lee, Bum-Jin; Hwang, Jeong-Ah; Ko, Kwang-Sup; Chung, Jin-Oh; Kim, Eun-Hee; Lee, Sang-Jun; Hong, Young-Shick

2011-10-12

The dependence of global green tea metabolome on plucking positions was investigated through (1)H nuclear magnetic resonance (NMR) analysis coupled with multivariate statistical data set. Pattern recognition methods, such as principal component analysis (PCA) and orthogonal projection on latent structure-discriminant analysis (OPLS-DA), were employed for a finding metabolic discrimination among fresh green tea leaves plucked at different positions from young to old leaves. In addition to clear metabolic discrimination among green tea leaves, elevations in theanine, caffeine, and gallic acid levels but reductions in catechins, such as epicatechin (EC), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and epigallocatechin-3-gallate (EGCG), glucose, and sucrose levels were observed, as the green tea plant grows up. On the other hand, the younger the green tea leaf is, the more theanine, caffeine, and gallic acid but the lesser catechins accumlated in the green tea leaf, revealing a reverse assocation between theanine and catechins levels due to incorporaton of theanine into catechins with growing up green tea plant. Moreover, as compared to the tea leaf, the observation of marked high levels of theanine and low levels of catechins in green tea stems exhibited a distinct tea plant metabolism between the tea leaf and the stem. This metabolomic approach highlights taking insight to global metabolic dependence of green tea leaf on plucking position, thereby providing distinct information on green tea production with specific tea quality.

Potentiation of Catechin Gallate-Mediated Sensitization of Staphylococcus aureus to Oxacillin by Nongalloylated Catechins†

PubMed Central

Stapleton, Paul D.; Shah, Saroj; Hara, Yukihiko; Taylor, Peter W.

2006-01-01

(−)−Epicatechin gallate (ECg) and (−)−epigallocatechin gallate (EGCg) reduce oxacillin resistance in mecA-containing strains of Staphylococcus aureus. Their binding to staphylococcal cells is enhanced by the nongalloyl analogues (−)−epicatechin (EC) and (−)−epigallocatechin (EGC). EC and EGC significantly increased the capacity of ECg and EGCg to reduce levels of staphylococcal oxacillin resistance. PMID:16436737

[Preparation and component analysis of tea pigments].

PubMed

Li, Daxiang; Wan, Xiaochun; Xia, Tao

2004-11-01

To prepare tea pigments. Tea pigments are prepared by solvent extraction from Sri lanka black tea. Tea pigments contains the components as follows: caffeine 1.77%, epigallocatechin 1.37%, catechin 1.20%, epicatechin 9.55%, epigallocatechin gallate 10.52%, epicatechin gallate 9.94%, theaflavin 10.34%, theaflavin monogallate 9.57%, theaflavin digallate 4.81%, thearubigin about 40.93%. The best proportions of the compound that are obtained with HPLC analysis.

Condensed tannins: (4β→8;2β→O→7)-linked procyanidins in Arachis hypogea L.

Treesearch

Joseph J. Karchesy; Richard W. Hemingway

1986-01-01

Mature, red peanut skins contain about 17% by weight of procyanidins. Nearly 50% of these compounds are low molecular weight oligomers that are soluble in ethyl acetate. The flavan-3-ols catechin and epicatechin are present in a ratio of 9 to 1 but in low concentration. Among the dimeric procyanidins, epicatechin-(4β→8;2β→...

Content of polyphenolic compounds in the Nigerian stimulants Cola nitida ssp. alba, Cola nitida ssp. rubra A. Chev, and Cola acuminata Schott & Endl and their antioxidant capacity.

PubMed

Atawodi, Sunday Ene-Ojo; Pfundstein, Beate; Haubner, Roswitha; Spiegelhalder, Bertold; Bartsch, Helmut; Owen, Robert Wyn

2007-11-28

Varieties of kola nuts (Cola nitida alba, Cola nitida rubra A. Chev, and Cola acuminata Schott & Endl), a group of popular Nigerian and West African stimulants, were analyzed for their content of secondary plant metabolites. The three varieties of the kola nuts contained appreciable levels of (+)-catechin (27-37 g/kg), caffeine (18-24 g/kg), (-)-epicatechin (20-21 g/kg), procyanidin B 1 [epicatechin-(4beta-->8)-catechin] (15-19 g/kg), and procyanidin B2 [epicatechin-(4beta-->8)-epicatechin] (7-10 g/kg). Antioxidant capacity of the extracts and purified metabolites was assessed by two HPLC-based and two colorimetric in vitro assays. Extracts of all varieties exhibited antioxidant capacity with IC 50 values in the range 1.70-2.83 and 2.74-4.08 mg/mL in the hypoxanthine/xanthine oxidase and 2-deoxyguanosine HPLC-based assays, respectively. Utilization of HPLC-based assays designed to reflect in situ generation of free radicals (e.g., HO(*)), as opposed to general assays (DPPH, FRAP) in common use which do not, indicate that, of the major secondary plant metabolites present in kola nut extracts, caffeine is potentially the more effective cancer chemopreventive metabolite in terms of its antioxidant capacity.

Molecular Approach to the Synergistic Effect on Astringency Elicited by Mixtures of Flavanols.

PubMed

Ramos-Pineda, Alba María; García-Estévez, Ignacio; Brás, Natércia F; Martín Del Valle, Eva M; Dueñas, Montserrat; Escribano Bailón, María Teresa

2017-08-09

The interactions between salivary proteins and wine flavanols (catechin, epicatechin, and mixtures thereof) have been studied by HPLC-DAD, isothermal titration microcalorimetry, and molecular dynamics simulations. Chromatographic results suggest that the presence of these flavanol mixtures could facilitate the formation of precipitates to the detriment of soluble aggregates. Comparison between the thermodynamic parameters obtained showed remarkably higher negative values of ΔG in the system containing the mixture of both flavanols in comparison to the systems containing individual flavanols, indicating a more favorable scenario in the mixing system. Also, the apparent binding constants were higher in this system. Furthermore, molecular dynamics simulations suggested a faster and greater cooperative binding of catechin and epicatechin to IB7 14 peptides when both types of flavanols are present simultaneously in solution.

Functional Characterization of Proanthocyanidin Pathway Enzymes from Tea and Their Application for Metabolic Engineering1[W][OA

PubMed Central

Pang, Yongzhen; Abeysinghe, I. Sarath B.; He, Ji; He, Xianzhi; Huhman, David; Mewan, K. Mudith; Sumner, Lloyd W.; Yun, Jianfei; Dixon, Richard A.

2013-01-01

Tea (Camellia sinensis) is rich in specialized metabolites, especially polyphenolic proanthocyanidins (PAs) and their precursors. To better understand the PA pathway in tea, we generated a complementary DNA library from leaf tissue of the blister blight-resistant tea cultivar TRI2043 and functionally characterized key enzymes responsible for the biosynthesis of PA precursors. Structural genes encoding enzymes involved in the general phenylpropanoid/flavonoid pathway and the PA-specific branch pathway were well represented in the library. Recombinant tea leucoanthocyanidin reductase (CsLAR) expressed in Escherichia coli was active with leucocyanidin as substrate to produce the 2R,3S-trans-flavan-ol (+)-catechin in vitro. Two genes encoding anthocyanidin reductase, CsANR1 and CsANR2, were also expressed in E. coli, and the recombinant proteins exhibited similar kinetic properties. Both converted cyanidin to a mixture of (+)-epicatechin and (−)-catechin, although in different proportions, indicating that both enzymes possess epimerase activity. These epimers were unexpected based on the belief that tea PAs are made from (−)-epicatechin and (+)-catechin. Ectopic expression of CsANR2 or CsLAR led to the accumulation of low levels of PA precursors and their conjugates in Medicago truncatula hairy roots and anthocyanin-overproducing tobacco (Nicotiana tabacum), but levels of oligomeric PAs were very low. Surprisingly, the expression of CsLAR in tobacco overproducing anthocyanin led to the accumulation of higher levels of epicatechin and its glucoside than of catechin, again highlighting the potential importance of epimerization in flavan-3-ol biosynthesis. These data provide a resource for understanding tea PA biosynthesis and tools for the bioengineering of flavanols. PMID:23288883

Effect of a walnut meal on postprandial oxidative stress and antioxidants in healthy individuals

PubMed Central

2014-01-01

Background In vitro studies rank walnuts (Juglans regia) among the plant foods high in antioxidant capacity, but whether the active constituents of walnuts are bioavailable to humans remains to be determined. The intention of this study was to examine the acute effects of consuming walnuts compared to refined fat on meal induced oxidative stress. At issue is whether the ellagitannins and tocopherols in walnuts are bioavailable and provide postprandial antioxidant protection. Methods A randomized, crossover, and controlled-feeding study was conducted to evaluate a walnut test meal compared to one composed of refined ingredients on postprandial serum antioxidants and biomarkers of oxidative status in healthy adults (n = 16) with at least 1 week between testing sessions. Following consumption of a low phenolic diet for one day and an overnight fast, blood was sampled prior to the test meals and at intervals up to 24 hours post ingestion and analyzed for total phenols, malondiadehyde (MDA), oxidized LDL, ferric reducing antioxidant power (FRAP), hydrophilic and lipophilic oxygen radical absorbance capacity (ORAC), uric acid, catechins and urinary excretion of phenylacetate metabolites and of urolithin A. Results Mixed linear models demonstrated a diet effect (P < 0.001) for plasma γ-tocopherol but not for α-tocopherol with the walnut meal. Following the walnut test meal, the incremental 5 hour area under the curve (AUC0-5h) was reduced 7.4% for MDA, increased 7.5% for hydrophilic and 8.5% for lipophilic ORAC and comparable for total phenols, FRAP and uric acid. Oxidized LDL was reduced at 2 hours after the walnut meal. Plasma concentrations of gallocatechin gallate (GCG), epicatechin gallate (ECG) and epicallocatechin gallate (EGCG) increased significantly at 1 hour after the walnut test meal. Quantities of urolithin-A excreted in the urine were significantly higher following the walnut meal. Conclusions Compared to the refined control meal, the walnut meal acutely increased postprandial γ-tocopherol and catechins and attenuated some measures of oxidative stress. PMID:24410903

Content Variation of Catechin Markers, Total Phenolics and Caffeine in Green Tea Dietary Supplements.

PubMed

Abourashed, Ehab A; Roberson, Cindy Leslie A; Elsharkawy, Nancy

2016-01-01

Green tea (Camellia sinensis) preparations are among the top selling products in the United States dietary supplements market. Numerous manufacturers claim different levels of specific catechin markers in their products while many others use total phenolic concentration instead, or not at all. Limited quality control results have been published for green tea dietary supplements over the past seven years. Thus, the goal of this work was to correlate determined levels of phenolics, catechins, and caffeine with manufacturer label claims for selected dietary supplement products (26 total) purchased in the United States. The Folin-Ciocalteu (FC) method was used to determine the total phenolic content while reversed-phase (RP) HPLC was used to quantify the major catechins: epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG). The developed HPLC method was validated for accuracy and precision. It utilized a C8 column with gradient elution of acetonitrile in 0.1% aqueous formic acid over 11 min total run time. Peak detection was performed at 280 nm. Caffeine was also included in the HPLC method as another non-phenolic alkaloid marker commonly found in green tea. Both methods showed a good correlation between the content of catechins and polyphenolic compounds in the selected products. The ranges of total catechins and polyphenol concentrations were 3.8-70.2% and 3.6-95.8%, respectively, while that of caffeine was 0.8-11.2%. The selected products displayed a wide range of marker levels. A lack of conformity in disclosing the actual levels of marker compounds was also noticed in the labeling of many products.

Evaluation of the inhibitory effects of quercetin-related flavonoids and tea catechins on the monoamine oxidase-A reaction in mouse brain mitochondria.

PubMed

Bandaruk, Yauhen; Mukai, Rie; Kawamura, Tomoyuki; Nemoto, Hisao; Terao, Junji

2012-10-17

Quercetin, a typical dietary flavonoid, is thought to exert antidepressant effects by inhibiting the monoamine oxidase-A (MAO-A) reaction, which is responsible for regulation of the metabolism of the neurotransmitter 5-hydroxytryptamine (5-HT) in the brain. This study compared the MAO-A inhibitory activity of quercetin with those of O-methylated quercetin (isorhamnetin, tamarixetin), luteolin, and green tea catechins ((-)-epicatechin, (-)-epicatechin gallate, (-)-epigallocatechin, and (-)-epigallocatechin gallate) by measuring the formation of the oxidative deamination product of 5-HT, 5-hydroxyindole aldehyde (5-HIAL), in mouse brain mitochondria. Quercetin was inferior to luteolin in the inhibition of MAO-A activity, whereas isorhamnetin, tamarixetin, and tea catechins scarcely exerted inhibitory activity. Quercetin did not affect MAO-A activity in mouse intestinal mitochondria, indicating that it does not evoke side effects on the metabolism of dietary monoamines in the gut. These data suggest that quercetin is a weak (but safe) MAO-A inhibitor in the modulation of 5-HT levels in the brain.

Green tea extract for periodontal health

PubMed Central

Venkateswara, Babu; Sirisha, K.; Chava, Vijay K.

2011-01-01

Tea, the commonly consumed beverage, is gaining increased attention in promoting overall health. In specific, green tea is considered a healthful beverage due to the biological activity of its polyphenols namely catechins. Among the polyphenols Epigallo catechin 3 gallate and Epicatechin 3 Gallate are the most predominant catechins. The antioxidant, antimicrobial, anticollagenase, antimutagenic, and c hemopreventive properties of these catechins proved to be helpful in the treatment of chronic diseases like periodontal disease. Studies have demonstrated that the type of processing mainly effects the concentration of catechins. Several epidemiological studies have proved that green tea also has some general health benefitting properties like antihypertensive, reduction of cardiovascular risk, antibacterial, antiviral, and antifungal activity. The present review concentrates on the effects of green tea in periodontal and general health. PMID:21772716

Carboxymethyl- and carboxyl-catechins from ripe Pu-er tea.

PubMed

Tian, Li-Wen; Tao, Mu-Ke; Xu, Min; Hu, Jing; Zhu, Hong-Tao; Xiong, Wen-Yong; Wang, Dong; Yang, Chong-Ren; Zhang, Ying-Jun

2014-12-17

Ripe Pu-er tea, a special microbial postfermented tea originated from Yunnan Province, China, since ancient times, is made from green Pu-er tea prepared from the leaves of Camellia sinensis var. assamica (Theaceae). Chemical investigation on thearubigin (n-BuOH-soluble) fraction of the commercial ripe Pu-er tea, led to the identification of four new flavan-3-ol derivatives, 8-carboxymethyl-(+)-catechin (1), 8-carboxymethyl-(+)-catechin methyl ester (2), 6-carboxymethyl-(+)-catechin (3), and 6-carboxyl-(-)-gallocatechin (4), together with 18 known compounds, including other three flavan-3-ol derivatives (5-7), 10 flavonoid glycosides (8-17), two hydrolyzable tannins (18 and 19), two quinic acid derivatives (20-21), and a purine alkaloid (22). Flavonoid glycosides 8-11 are reported from tea plants for the first time. The thearubigin fraction of ripe Pu-er tea was qualitatively analyzed by HPLC, and gallic acid was found to be the major component. Compounds 4, 6-17, 21 and 22 were tested for their acute activities on insulin sensitivity in differentiated 3T3-L1 adipocytes, but none of them showed significant bioactivity at a concentration of 10 μM.

Senna singueana: Antioxidant, Hepatoprotective, Antiapoptotic Properties and Phytochemical Profiling of a Methanol Bark Extract.

PubMed

Sobeh, Mansour; Mahmoud, Mona F; Hasan, Rehab A; Cheng, Haroan; El-Shazly, Assem M; Wink, Michael

2017-09-08

Natural products are considered as an important source for the discovery of new drugs to treat aging-related degenerative diseases and liver injury. The present study profiled the chemical constituents of a methanol extract from Senna singueana bark using HPLC-PDA-ESI-MS/MS and 36 secondary metabolites were identified. Proanthocyanidins dominated the extract. Monomers, dimers, trimers of (epi)catechin, (epi)gallocatechin, (epi)guibourtinidol, (ent)cassiaflavan, and (epi)afzelechin represented the major constituents. The extract demonstrated notable antioxidant activities in vitro: In DPPH (EC 50 of 20.8 µg/mL), FRAP (18.16 mM FeSO₄/mg extract) assays, and total phenolic content amounted 474 mg gallic acid equivalent (GAE)/g extract determined with the Folin-Ciocalteu method. Also, in an in vivo model, the extract increased the survival rate of Caenorhabditis elegans worms pretreated with the pro-oxidant juglone from 43 to 64%, decreased intracellular ROS inside the wild-type nematodes by 47.90%, and induced nuclear translocation of the transcription factor DAF-16 in the transgenic strain TJ356. Additionally, the extract showed a remarkable hepatoprotective activity against d-galactosamine (d-GalN) induced hepatic injury in rats. It significantly reduced elevated AST (aspartate aminotransferase), and total bilirubin. Moreover, the extract induced a strong cytoplasmic Bcl-2 expression indicating suppression of apoptosis. In conclusion, the bark extract of S. sengueana represents an interesting candidate for further research in antioxidants and liver protection.

Estimated dietary intake and major food sources of polyphenols in the Polish arm of the HAPIEE study☆

PubMed Central

Grosso, Giuseppe; Stepaniak, Urszula; Topor-Mądry, Roman; Szafraniec, Krystyna; Pająk, Andrzej

2014-01-01

Objective The aim of this study was to estimate the intake of known individual polyphenols and their major dietary sources in the Polish arm of the HAPIEE (Health, Alcohol and Psychosocial factors In Eastern Europe) study. Methods A total of 10,477 random sample (45–69 y) of urban population of Krakow, Poland, completed a validated 148-item food frequency questionnaire. Polyphenol intake was calculated by matching food consumption data with the recently developed Phenol-Explorer database. Results The mean intake of polyphenols was 1756.5 ± 695.8 mg/d (median = 1662.5 mg/d). The main polyphenol groups were flavonoids (897 mg/d) and phenolic acids (800 mg/d). A total of 347 polyphenols from 19 polyphenol subclasses were found. The individual compounds with the highest intakes were isomers of chlorogenic acid (i.e., 5-caffeoylquinic acid and 4-caffeoylquinic acid) among hydroxycinnamic acids (average intake 150 mg/d), that largely originated from coffee, and compounds belonging to the catechin chemical family (i.e., [+]-gallocatechin, [-]-epigallocatechin 3-O-gallate, and [-]-epicatechin) among flavanols (average intake 50 mg/d), that mostly originated from tea and cocoa products. Conclusions The current study provides the most updated data for individual polyphenols intake in the diet of a well-established nutritional cohort. These findings will be useful to assess potential beneficial role on health of specific foods with high polyphenol content and characterize the effects of individual phenolic compounds. PMID:25280419

Use of the fluorescence quantum yield for the determination of the number-average molecular weight of polymers of epicatechin with 4β→8 interflavin bonds

Treesearch

D. Cho; W.L. Mattice; L.J. Porter; Richard W. Hemingway

1989-01-01

Excitation at 280 nm produces a structureless emission band with a maximum at 321-324 nm for dilute solutions of catechin, epicatechin, and their oligomers in l,4-dioxane or water. The fluorescence quantum yield, Q, has been measured in these two solvents for five dimers, a trimer, a tetramer, a pentamer, a hexamer, and a polymer in which the monomer...

TRANSPARENT TESTA10 Encodes a Laccase-Like Enzyme Involved in Oxidative Polymerization of Flavonoids in Arabidopsis Seed CoatW⃞

PubMed Central

Pourcel, Lucille; Routaboul, Jean-Marc; Kerhoas, Lucien; Caboche, Michel; Lepiniec, Loïc; Debeaujon, Isabelle

2005-01-01

The Arabidopsis thaliana transparent testa10 (tt10) mutant exhibits a delay in developmentally determined browning of the seed coat, also called the testa. Seed coat browning is caused by the oxidation of flavonoids, particularly proanthocyanidins, which are polymers of flavan-3-ol subunits such as epicatechin and catechin. The tt10 mutant seeds accumulate more epicatechin monomers and more soluble proanthocyanidins than wild-type seeds. Moreover, intact testa cells of tt10 cannot trigger H2O2-independent browning in the presence of epicatechin and catechin, in contrast with wild-type cells. UV–visible light detection and mass spectrometry revealed that the major oxidation products obtained with epicatechin alone are yellow dimers called dehydrodiepicatechin A. These products differ from proanthocyanidins in the nature and position of their interflavan linkages. Flavonol composition was also affected in tt10 seeds, which exhibited a higher ratio of quercetin rhamnoside monomers versus dimers than wild-type seeds. We identified the TT10 gene by a candidate gene approach. TT10 encodes a protein with strong similarity to laccase-like polyphenol oxidases. It is expressed essentially in developing testa, where it colocalizes with the flavonoid end products proanthocyanidins and flavonols. Together, these data establish that TT10 is involved in the oxidative polymerization of flavonoids and functions as a laccase-type flavonoid oxidase. PMID:16243908

Development of an isocratic HPLC method for catechin quantification and its application to formulation studies.

PubMed

Li, Danhui; Martini, Nataly; Wu, Zimei; Wen, Jingyuan

2012-10-01

The aim of this study was to develop a simple, rapid and accurate isocratic HPLC analytical method to qualify and quantify five catechin derivatives, namely (+)-catechin (C), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epicatechin (EC) and (-)-epigallocatechin gallate (EGCG). To validate the analytical method, linearity, repeatability, intermediate precision, sensitivity, selectivity and recovery were investigated. The five catechin derivatives were completely separated by HPLC using a mobile phase containing 0.1% TFA in Milli-Q water (pH 2.0) mixed with methanol at the volume ratio of 75:25 at a flow rate of 0.8 ml/min. The method was shown to be linear (r²>0.99), repeatable with instrumental precision<2.0 and intra-assay precision<2.5 (%CV, percent coefficient of variation), precise with intra-day variation<1 and inter-day variation<2.5 (%CV, percent coefficient of variation) and sensitive (LOD<1 μg/mL and LOQ<3 μg/mL) over the calibration range for all five derivatives. Derivatives could be fully recovered in the presence of niosomal formulation (recovery rates>91%). Selectivity of the method was proven by the forced degradation studies, which showed that under acidic, basic, oxidation temperature and photolysis stresses, the parent drug can be separated from the degradation products by means of this analytical method. The described method was successfully applied in the in vitro release studies of catechin-loaded niosomes to manifest its utility in formulation characterization. Obtained results indicated that the drug release from niosomal formulations was a biphasic process and a diffusion mechanism regulated the permeation of catechin niosomes. Copyright © 2012 Elsevier B.V. All rights reserved.

Bioavailability of catechins from guaraná (Paullinia cupana) and its effect on antioxidant enzymes and other oxidative stress markers in healthy human subjects.

PubMed

Yonekura, Lina; Martins, Carolina Aguiar; Sampaio, Geni Rodrigues; Monteiro, Marcela Piedade; César, Luiz Antônio Machado; Mioto, Bruno Mahler; Mori, Clara Satsuki; Mendes, Thaíse Maria Nogueira; Ribeiro, Marcelo Lima; Arçari, Demetrius Paiva; Torres, Elizabeth Aparecida Ferraz da Silva

2016-07-13

We assessed the effects of guaraná (Paullinia cupana) consumption on plasma catechins, erythrocyte antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase) and biomarkers of oxidative stress (ex vivo LDL oxidation, plasma total antioxidant status and ORAC, and lymphocyte single cell gel electrophoresis) in healthy overweight subjects. Twelve participants completed a 15-day run-in period followed by a 15-day intervention with a daily intake of 3 g guaraná seed powder containing 90 mg (+)-catechin and 60 mg (-)-epicatechin. Blood samples were taken on the first and last day of the intervention period, fasting and 1 h post-dose. The administration of guaraná increased plasma ORAC, while reducing ex vivo LDL oxidation (only in the first study day) and hydrogen peroxide-induced DNA damage in lymphocytes, at 1 h post-dose. Plasma catechin (0.38 ± 0.12 and 0.44 ± 0.18 nmol mL(-1)), epicatechin (0.59 ± 0.18 and 0.64 ± 0.25 nmol mL(-1)) and their methylated metabolites were observed at 1 h post-dose but were almost negligible after overnight fasting. The activities of catalase (in both study days) and glutathione peroxidase (in the last intervention day) increased at 1 h post-dose. Furthermore, the activity of both enzymes remained higher than the basal levels in overnight-fasting individuals on the last intervention day, suggesting a prolonged effect of guaraná that continues even after plasma catechin clearance. In conclusion, guaraná catechins are bioavailable and contribute to reduce the oxidative stress of clinically healthy individuals, by direct antioxidant action of the absorbed phytochemicals and up-regulation of antioxidant/detoxifying enzymes.

Effect of glutathione during bottle storage of sparkling wine.

PubMed

Webber, Vanessa; Dutra, Sandra Valduga; Spinelli, Fernanda Rodrigues; Carnieli, Gilberto João; Cardozo, Alejandro; Vanderlinde, Regina

2017-02-01

Reduced glutathione (GSH) is an efficient antioxidant on limiting browning, losing varietal aromas and off-flavor formation. Therefore, this study aims to evaluate the effect of GSH addition (10, 20 and 30mgL(-1)) after the disgorging of the sparkling wine during storage. The sparkling wines were analyzed at 1, 6, 12 and 18months of storage according to the color index, concentration of the free SO2, phenolic compounds, catechin, epicatechin, caffeic acid, coumaric acid, acetaldehyde, total and reduced glutathione. The results show that GSH concentration decreased to the level of the control sparkling wine during the first 6months, and the total glutathione gradually declined up to 12months. The GSH reduces browning and acetaldehyde formation for up to 12months. However, the presence of glutathione had low or no influence on the concentration of free SO2, total phenolics, catechin, epicatechin, caffeic and coumaric acids. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enrichment of Biscuits with Matcha Green Tea Powder: Its Impact on Consumer Acceptability and Acute Metabolic Response

PubMed Central

Phongnarisorn, Benjapor; Orfila, Caroline; Holmes, Melvin; Marshall, Lisa J.

2018-01-01

Matcha green tea powder (MGTP) is made with finely ground green tea leaves that are rich in phytochemicals, most particularly catechins. Shortbread biscuits were enriched with MGTP and evaluated for consumer acceptability and potential functional health properties. Baking decreased the content of total catechins by 19% compared to dough, although epimerization increased the amount of (+)-gallocatechin gallate at the expense of other catechins such as (−)-epigallocatechin gallate. Consumer acceptability tests using a 9-point hedonic scale showed that consumers preferred enriched biscuits with low content of MGTP (2 g of MGTP 100 g−1 of flour), and an increase of sugar content did not significantly improve the acceptability of MGTP-enriched biscuits. Overall, enrichment of biscuits with MGTP did not significantly affect the postprandial glucose or triglyceride response (area under curve) compared to non-enriched biscuits consumed with water or MGTP drink. Enriching biscuits with Matcha green tea is acceptable to consumers, but may not bring significant postprandial effects. PMID:29389844

Enrichment of Biscuits with Matcha Green Tea Powder: Its Impact on Consumer Acceptability and Acute Metabolic Response.

PubMed

Phongnarisorn, Benjapor; Orfila, Caroline; Holmes, Melvin; Marshall, Lisa J

2018-02-01

Matcha green tea powder (MGTP) is made with finely ground green tea leaves that are rich in phytochemicals, most particularly catechins. Shortbread biscuits were enriched with MGTP and evaluated for consumer acceptability and potential functional health properties. Baking decreased the content of total catechins by 19% compared to dough, although epimerization increased the amount of (+)-gallocatechin gallate at the expense of other catechins such as (-)-epigallocatechin gallate. Consumer acceptability tests using a 9-point hedonic scale showed that consumers preferred enriched biscuits with low content of MGTP (2 g of MGTP 100 g -1 of flour), and an increase of sugar content did not significantly improve the acceptability of MGTP-enriched biscuits. Overall, enrichment of biscuits with MGTP did not significantly affect the postprandial glucose or triglyceride response (area under curve) compared to non-enriched biscuits consumed with water or MGTP drink. Enriching biscuits with Matcha green tea is acceptable to consumers, but may not bring significant postprandial effects.

Analysis of some selected catechins and caffeine in green tea by high performance liquid chromatography.

PubMed

El-Shahawi, M S; Hamza, A; Bahaffi, S O; Al-Sibaai, A A; Abduljabbar, T N

2012-10-15

Green tea seems to have a positive impact on health due to the catechins-found as flavanols. Thus, the present study was aimed to develop a low cost reversed phase high performance liquid chromatographic (HPLC) method for simultaneous determination of flavanol contents, namely catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin 3-gallate (ECG) and epigallocatechin 3-gallate (EGCG) and caffeine in 29 commercial green tea samples available in a Saudi Arabian local market. A C-18 reversed-phase column, acetonitrile-trifluoroacetic acid as a mobile phase, coupled with UV detector at 205 nm, was successfully used for precise analysis of the tested analytes in boiled water of digested tea leaves. The average values of N (No. of theoretical plates), HETP (height equivalent of theoretical plates) and R(s) (separation factor) (at 10 μg ml(-1) of the catechins EC, EGC, EGCG and ECG) were 2.6×10(3)±1.2×10(3), 1.7×10(-3)±4.7×10(-4) cm and 1.7±5.53×10(-2), respectively. The developed HPLC method demonstrated excellent performance, with low limits of detection (LOD) and quantification (LOQ) of the tested catechins of 0.004-0.05 μg ml(-1) and 0.01-0.17 μg ml(-1), respectively, and recovery percentages of 96-101%. The influence of infusion time (5-30 min) and temperature on the content of the flavanols was investigated by HPLC. After a 5 min infusion of the tea leaves, the average concentrations of caffeine, catechin, EC, EGC, ECG and EGCG were found to be in the ranges 0.086-2.23, 0.113-2.94, 0.58-10.22, 0.19-24.9, 0.22-13.9 and 1.01-43.3 mg g(-1), respectively. The contents of caffeine and catechins followed the sequence: EGCG>EGC>ECG>EC>C>caffeine. The method was applied satisfactorily for the analysis of (+)-catechin, even at trace and ultra trace concentrations of catechins. The method was rapid, accurate, reproducible and ideal for routine analysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Resolving Identification Issues of Saraca asoca from Its Adulterant and Commercial Samples Using Phytochemical Markers

PubMed Central

Hegde, Satisha; Hegde, Harsha Vasudev; Jalalpure, Sunil Satyappa; Peram, Malleswara Rao; Pai, Sandeep Ramachandra; Roy, Subarna

2017-01-01

Saraca asoca (Roxb.) De Wilde (Ashoka) is a highly valued endangered medicinal tree species from Western Ghats of India. Besides treating cardiac and circulatory problems, S. asoca provides immense relief in gynecological disorders. Higher price and demand, in contrast to the smaller population size of the plant, have motivated adulteration with other plants such as Polyalthia longifolia (Sonnerat) Thwaites. The fundamental concerns in quality control of S. asoca arise due to its part of medicinal value (Bark) and the chemical composition. Phytochemical fingerprinting with proper selection of analytical markers is a promising method in addressing quality control issues. In the present study, high-performance liquid chromatography of phenolic compounds (gallic acid, catechin, and epicatechin) coupled to multivariate analysis was used. Five samples each of S. asoca, P. longifolia from two localities alongside five commercial market samples showed evidence of adulteration. Subsequently, multivariate hierarchical cluster analysis and principal component analysis was established to discriminate the adulterants of S. asoca. The proposed method ascertains identification of S. asoca from its putative adulterant P. longifolia and commercial market samples. The data generated may also serve as baseline data to form a quality standard for pharmacopoeias. SUMMARY Simultaneous quantification of gallic acid, catechin, epicatechin from Saraca asoca by high-performance liquid chromatographyDetection of S. asoca from adulterant and commercial samplesUse of analytical method along with a statistical tool for addressing quality issues. Abbreviations used: HPLC: High Performance Liquid Chromatography; RP-HPLC: Reverse Phase High Performance Liquid Chromatography; CAT: Catechin; EPI: Epicatechin; GA: Gallic acid; PCA: Principal Component Analysis. PMID:28808391

Quercetin and fisetin enhanced the small intestine cellular uptake and plasma levels of epi-catechins in in vitro and in vivo models.

PubMed

Chung, Jin-Oh; Lee, Seon-Bong; Jeong, Kang-Hyun; Song, Ji-Hoon; Kim, Su-Kyung; Joo, Kyung-Mi; Jeong, Hyun-Woo; Choi, Jin-Kyu; Kim, Jeong-Kee; Kim, Wan-Gi; Shin, Song-Seok; Shim, Soon-Mi

2018-01-24

Quercetin and fisetin, known as catechol-containing flavonoids, could positively affect the absorption of catechins due to their strong affinity for catechol-O-methyl transferase (COMT), which can methylate and cause the excretion of catechins. The current study examined the effect of quercetin and fisetin on the absorption of epi-catechins (ECs) by using a Caco-2 cell line and an in vivo model. The intestinal transport of total catechins by Caco-2 cells was enhanced from 1.3- to 1.6-fold and 1.4- to 1.7-fold by adding quercetin and fisetin, respectively, compared to the control. It was even higher in the treatment with a mixture of quercetin and fisetin. While EC had the highest value of intestinal transport (169% of the control) in 10% quercetin treatment, EGC (235%), EGCG (244%), and ECG (242%) were significantly transported in the treatment with a 5% mixture of quercetin and fisetin (p < 0.05). In an in vivo pharmacokinetic study, the values of the area under the plasma concentration-time curve (AUC, ng h mL -1 ) were also higher in rats orally administered EGCG with 10% quercetin (365.5 ± 25.5) or 10% fisetin (825.3 ± 46.7) than in those administered EGCG only (111.3 ± 13.1). Methylated quercetin and methylated fisetin were determined to be m/z 317.24 and m/z 301.25 [M + H] + with their own product ions, respectively. The results indicate that quercetin or fisetin is superior to ECs for methylation by COMT.

Roasting conditions for preserving cocoa flavan-3-ol monomers and oligomers: interesting behaviour of Criollo clones.

PubMed

De Taeye, Cédric; Bodart, Marie; Caullet, Gilles; Collin, Sonia

2017-09-01

Cocoa bean roasting is important for creating the typical chocolate aroma through Maillard reactions, but it is also a key step deleterious to the polyphenol content and profile. Compared with usual roasting at 150 °C, keeping the beans for 30 min at 120 °C or for 1 h at 90 °C proved much better for preventing strong degradation of native P1, P2 and P3 flavan-3-ols in cocoa (shown for Forastero, Trinitatio and Criollo cultivars). Surprisingly, Cuban, Mexican and Malagasy white-seeded beans behaved atypically when roasted for 30 min at 150 °C, releasing a pool of catechin. Enantiomeric chromatographic separation proved that this pool contained mainly (-)-catechin issued from (-)-epicatechin by epimerisation. As the (-)-epicatechin content remained relatively constant through Criollo bean roasting, flavan-3-ol monomers must have been regenerated from oligomers. This emergence of (-)-catechin in Criollo beans only, reported here for the first time, could be due to increased flavan-3-ol monomer stability in the absence of anthocyanidin-derived products. The degradation rate of flavan-3-ols through roasting is higher in cocoa beans containing anthocyani(di)ns. The liberation of a pool of (-)-catechin when submitted to roasting at 150 °C allows to distinguish white-seeded cultivars. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

GREEN TEA CATECHINS ARE POTENT SENSITIZERS OF RYANODINE RECEPTOR TYPE 1 (RYR1)

PubMed Central

Feng, Wei; Cherednichenko, Gennady; Ward, Chris W.; Padilla, Isela T.; Cabrales, Elaine; Lopez, José R.; Eltit, José M.; Allen, Paul D.; Pessah, Isaac N.

2010-01-01

Catechins, polyphenols extracted from green tea leaves, have a broad range of biological activities although the specific molecular mechanisms responsible are not known. At the high experimental concentrations typically used polyphenols bind to membrane phospholipid and also are easily auto-oxidized to generate superoxide anion and semiquinones, and can adduct to protein thiols. We report that the type 1 ryanodine receptor (RyR1) is a molecular target that responds to nanomolar (−)-epigallocatechin-3-gallate (EGCG) and (−)-epicatechin-3-gallate (ECG). Single channel analyses demonstrate EGCG (5-10nM) increases channel open probability (Po) 2-fold, by lengthening open dwell time. The degree of channel activation is concentration dependent and is rapidly and fully reversible. Four related catechins, EGCG, ECG, EGC ((−)-epigallocatechin) and EC ((−)-epicatechin) showed a rank order of activity toward RyR1 (EGCG>ECG>>EGC>>>EC). EGCG and ECG enhance the sensitivity of RyR1 to activation by ≤100μM cytoplasmic Ca2+ without altering inhibitory potency by >100μM Ca2+. EGCG as high as 10μM in the extracellular medium potentiated Ca2+ transient amplitudes evoked by electrical stimuli applied to intact myotubes and adult FDB fibers, without eliciting spontaneous Ca2+ release or slowing Ca2+ transient recovery. The results identify RyR1 as a sensitive target for the major tea catechins EGCG and ECG, and this interaction is likely to contribute to their observed biological activities. PMID:20471964

Quantitative comparison of cancer and normal cell adhesion using organosilane monolayer templates: an experimental study on the anti-adhesion effect of green-tea catechins.

PubMed

Sakamoto, Rumi; Kakinuma, Eisuke; Masuda, Kentaro; Takeuchi, Yuko; Ito, Kosaku; Iketaki, Kentaro; Matsuzaki, Takahisa; Nakabayashi, Seiichiro; Yoshikawa, Hiroshi Y; Yamamoto, Hideaki; Sato, Yuko; Tanii, Takashi

2016-09-01

The main constituent of green tea, (-)-Epigallocatechin-3-O-gallate (EGCG), is known to have cancer-specific chemopreventive effects. In the present work, we investigated how EGCG suppresses cell adhesion by comparing the adhesion of human pancreatic cancer cells (AsPC-1 and BxPC-3) and their counterpart, normal human embryonic pancreas-derived cells (1C3D3), in catechin-containing media using organosilane monolayer templates (OMTs). The purpose of this work is (1) to evaluate the quantitativeness in the measurement of cell adhesion with the OMT and (2) to show how green-tea catechins suppress cell adhesion in a cancer-specific manner. For the first purpose, the adhesion of cancer and normal cells was compared using the OMT. The cell adhesion in different type of catechins such as EGCG, (-)-Epicatechin-3-O-gallate (ECG) and (-)-Epicatechin (EC) was also evaluated. The measurements revealed that the anti-adhesion effect of green-tea catechins is cancer-specific, and the order is EGCG≫ECG>EC. The results agree well with the data reported to date, showing the quantitativeness of the new method. For the second purpose, the contact area of cells on the OMT was measured by reflection interference contrast microscopy. The cell-OMT contact area of cancer cells decreases with increasing EGCG concentration, whereas that of normal cells remains constant. The results reveal a twofold action of EGCG on cancer cell adhesion-suppressing cell attachment to a candidate adhesion site and decreasing the contact area of the cells-and validates the use of OMT as a tool for screening cancer cell adhesion.

Simultaneous quantification of catechin, epicatechin, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, piperine and glycyrrhetinic acid in rat plasma by HPLC-MS/MS: application to a pharmacokinetic study of Longhu Rendan pills.

PubMed

Wang, Tianming; Ding, Liqing; Jin, Huajia; Shi, Rong; Li, Yuanyuan; Wu, Jiasheng; Li, Yifei; Zhu, Li; Ma, Yueming

2016-08-01

A sensitive, specific, accurate HPLC-MS/MS method was developed and validated for the simultaneous quantification of catechin, epicatechin, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, piperine and glycyrrhetinic acid from Longhu Rendan pills in rat plasma. Chromatographic separation was performed with a Hypersil Gold C18 column using a gradient of methanol and 0.01% acetic acid containing 0.2 mm ammonium acetate as mobile phase. The analytes were quantified on a triple quadrupole mass spectrometer, operating in selected reaction monitoring mode and switching the electrospray ion source polarity between positive and negative modes in a single run. The calibration curves of catechin, epicatechin, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, piperine and glycyrrhetinic acid were linear over the concentration ranges of 5-2000, 5-2000, 0.5-200, 0.5-200, 0.25-100, 0.25-100, 0.025-10 and 0.50-200 ng mL(-1) , respectively. The intra- and inter-assay precisions and accuracies were <11.6 and 91.9-108.2%, respectively, for all analytes. Matrix effects for all analytes were between 88.2 and 114.2%. Stability testing showed that all analytes were stable in plasma at 24 °C for 3 h, at 4 °C for 24 h, after three freeze-thaw cycles, and at -80 °C for 15 days. The method was successfully applied to an in vivo study evaluating the pharmacokinetics of multiple nonvolatile compounds following intragastric administration of Longhu Rendan pills to rats. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Free radical-scavenging activities of Crataegus monogyna extracts.

PubMed

Bernatoniene, Jurga; Masteikova, Rūta; Majiene, Daiva; Savickas, Arūnas; Kevelaitis, Egidijus; Bernatoniene, Rūta; Dvorácková, Katerina; Civinskiene, Genuvaite; Lekas, Raimundas; Vitkevicius, Konradas; Peciūra, Rimantas

2008-01-01

The aim of this study was to investigate antiradical activity of aqueous and ethanolic hawthorn fruit extracts, their flavonoids, and flavonoid combinations. Total amount of phenolic compounds and the constituents of flavonoids were determined using a high-performance liquid chromatography. The antioxidant activity of Crataegus monogyna extracts and flavonoids (chlorogenic acid, hyperoside, rutin, quercetin, vitexin-2O-rhamnoside, epicatechin, catechin, and procyanidin B(2)) quantitatively was determined using the method of spectrophotometry (diphenyl-1-picrylhydrazyl (DPPH.) radical scavenging assay and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid)(ABTS.+) radical cation decolorization assay). The level of tyrosine nitration inhibition was determined using a high-performance liquid chromatography. Ethanolic hawthorn fruit extract contained 182+/-4 mg/100 mL phenolic compounds, i.e. threefold more, as compared to aqueous extract. The antioxidant activity according to DPPH. reduction in the ethanolic extracts was higher 2.3 times (P<0.05). The ABTS.+ technique showed that the effect of ethanolic extracts was by 2.5 times stronger than that of aqueous extracts. Tyrosine nitration inhibition test showed that the effect of ethanolic extracts was by 1.4 times stronger than that of aqueous extracts. The investigation of the antiradical activity of the active constituents in aqueous and ethanolic extracts revealed that epicatechin and catechin contribute to radical-scavenging properties more than other components. Procyanidin B(2) only insignificantly influenced the antiradical activity of the extracts. Both aqueous and ethanolic hawthorn extracts had antiradical activity, but ethanolic extract had stronger free radical-scavenging properties, compared to the aqueous extract. The antioxidant activity of the studied preparations was mostly conditioned by epicatechin and catechin. The individual constituents of both extracts had weaker free radical-scavenging properties than the combination of these substances did.

Anti-inflammatory and antinociceptive activities of Croton urucurana Baillon bark.

PubMed

Cordeiro, Kátia Wolff; Felipe, Josyelen Lousada; Malange, Kauê Franco; do Prado, Pâmela Rafaela; de Oliveira Figueiredo, Patrícia; Garcez, Fernanda Rodrigues; de Cássia Freitas, Karine; Garcez, Walmir Silva; Toffoli-Kadri, Mônica Cristina

2016-05-13

Croton urucurana (Euphorbiaceae) is popularly used in Brazil to treat inflammatory processes, pain, and gastric ulcers. To evaluate the anti-inflammatory and antinociceptive properties of the methanol extract from the bark of C. urucurana (MECu) in mice and identify its chemical constituents. The extract was characterized by UHPLC-DAD-ESI-Q-TOF-MS/MS. Extract doses of 25, 100, and 400mg/kg were employed in the biological assays. Evaluation of anti-inflammatory activity was based on paw edema and leukocyte recruitment into the peritoneal cavity of mice, both induced by carrageenan. Abdominal writhing caused by acetic acid and duration of formalin-induced paw-licking were the models employed to evaluate antinociceptive activity. Ten compounds were identified in the extract: (+)-gallocatechin (1), procyanidin B3 (2), (+)-catechin (3), (-)-epicatechin (4), tembetarine (5), magnoflorine (6), taspine (7), methyl-3-oxo-12-epi-barbascoate (8), methyl-12-epi-barbascoate (9), and hardwickiic acid (10). This is the first report of compounds 2, 4, 6, 7, and 10 in C. urucurana and compound 5 in the genus Croton. In addition to inhibiting paw edema and leukocyte recruitment (particularly of polymorphonuclear cells) into the peritoneal cavity of mice, MECu reduced the number of abdominal writhings induced by acetic acid and the duration of formalin-induced paw licking. The methanol extract of C. urucurana bark exhibited anti-inflammatory and antinociceptive properties, corroborating its use in folk medicine. These effects may be related to the presence of diterpenes, alkaloids, and flavonoids. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Assessment of bioactive metabolites and hypolipidemic effect of polyphenolic-rich red cabbage extract.

PubMed

Cruz, Alice Buss; Pitz, Heloísa da Silva; Veber, Bruno; Bini, Larissa Alida; Maraschin, Marcelo; Zeni, Ana Lúcia Bertarello

2016-12-01

Cardiovascular disease is the leading cause of death worldwide and the consumption of red cabbage (Brassica oleracea var. capitata f. rubra DC. - Brassicaceae) has been linked with the reduction risk of chronic diseases. The present study assesses the bioactive metabolites and hypolipidemic effect of red cabbage on rats. The content of total phenols, flavonoids, anthocyanins, carotenoids, ascorbic acid and antioxidant capacity were assessed, while individual phenolic acids and flavonoids were detected using reverse phase-high performance liquid chromatography (HPLC) analysis. Acute hypolipidemic activity of aqueous extract of red cabbage (RC - 125, 250 and 500 mg/kg) was investigated using a Triton WR-1339 (400 mg/kg) induced hyperlipidemic Wistar rats compared to fenofibrate (65 mg/kg). The HPLC analysis of extracts revealed eight phenolic acids, gallic, protocatechuic, p-hydroxybenzoic, m-coumaric, syringic, caffeic, cinnamic, dicaffeoylquinic and three flavonoids, epicatechin, epigallocatechin, gallocatechin. Furthermore, the aqueous extract showed higher amounts of total phenolics (116.00 mg/g), flavonoids (161.32 μg/g) and, antioxidant activity (87.19%) than the hydromethanolic (89.33 mg/g, 123.34 μg/g and 75.07%), respectively. The RC significantly (p < 0.001) ameliorated the levels of cholesterol, triglycerides and lipoproteins alterations in hyperlipidemic rats without toxicity. Herein, the RC presented the higher amounts of phenolics and flavonoids comparing with the hydromethanolic extract. Additionally, the RC showed as the majority compounds, dicaffeoylquinic and cinnamic acids, and the flavonoids epicatechin and gallocatechin. Furthermore, the RC demonstrated a beneficial effect against hypercholesterolemia and hypertriglyceridemia, demonstrating its potential therapeutic effect on these risk factors of cardiovascular diseases.

Development of CE-dual opposite carbon-fiber micro-disk electrode detection for peak purity assessment of polyphenols in red wine.

PubMed

Du, Fuying; Fung, Ying Sing

2010-07-01

A new dual opposite carbon-fiber micro-disk electrode detector was fabricated and tested for hyphenation with CE in the polyphenol determination. Under optimized conditions, CE-dual opposite carbon-fiber micro-disk electrode was found able to baseline separate and determine five important polyphenols (trans-resveratrol, (+)-catechin, (-)-epicatechin, quercetin and gallic acid) in red wine within 16 min with low detection limit (0.031-0.21 mg/L) and satisfactory repeatability (2.0-3.3% RSD, n=5). The opposite dual electrode enables simultaneous determination of CE eluents for current ratio measured at +0.8 and +1.0 V versus Ag/AgCl for the peak purity assessment. The capability to identify the presence of co-migrating impurities in given polyphenol peaks was demonstrated in a mixed standard solution with overlapping (+)-catechin and (-)-epicatechin peaks and in commercial red wine with unknown impurities and confirming the reliability for polyphenol quantitation in red wine with matching migration time and current ratio.

Determination of polyphenolic compounds of red wines by UV-VIS-NIR spectroscopy and chemometrics tools.

PubMed

Martelo-Vidal, M J; Vázquez, M

2014-09-01

Spectral analysis is a quick and non-destructive method to analyse wine. In this work, trans-resveratrol, oenin, malvin, catechin, epicatechin, quercetin and syringic acid were determined in commercial red wines from DO Rías Baixas and DO Ribeira Sacra (Spain) by UV-VIS-NIR spectroscopy. Calibration models were developed using principal component regression (PCR) or partial least squares (PLS) regression. HPLC was used as reference method. The results showed that reliable PLS models were obtained to quantify all polyphenols for Rías Baixas wines. For Ribeira Sacra, feasible models were obtained to determine quercetin, epicatechin, oenin and syringic acid. PCR calibration models showed worst reliable of prediction than PLS models. For red wines from mencía grapes, feasible models were obtained for catechin and oenin, regardless the geographical origin. The results obtained demonstrate that UV-VIS-NIR spectroscopy can be used to determine individual polyphenolic compounds in red wines. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fractionation and structural characterization of polyphenolic antioxidants from seed shells of Japanese horse chestnut (Aesculus turbinata BLUME).

PubMed

Ogawa, Satoshi; Kimura, Hideto; Niimi, Ai; Katsube, Takuya; Jisaka, Mitsuo; Yokota, Kazushige

2008-12-24

Seed shells of the Japanese horse chestnut (Aesculus turbinata BLUME) contain high levels of polyphenolic antioxidants. These compounds were extracted, fractionated, and finally separated into three fractions, F1, F2, and F3, according to their degrees of polymerization. The structures of the isolated fractions were characterized by a combination of mass spectrometric analyses. F1 contained mainly low molecular weight phenolic substances, including procyanidin trimers. The predominant fractions F2 and F3 consisted of polymeric proanthocyanidins having a series of heteropolyflavan-3-ols, (+)-catechin/(-)-epicatechin units, and polymerization degrees of 19 and 23, respectively. The polyphenol polymers had doubly linked A-type interflavan linkages in addition to single B-type bonds without gallic acid esterified to them. The isolated polyphenolic compounds exhibited potent antioxidative activities comparable to monomeric (+)-catechin and (-)-epicatechin, or more efficacious than those monomers. The results suggest the potential usefulness of polyphenol polymers from seed shells as a source for nutraceutical factors.

Effect of catechin and its derivatives on inhibition of polyphenoloxidase and melanosis of Pacific white shrimp.

PubMed

Sae-Leaw, Thanasak; Benjakul, Soottawat; Simpson, Benjamin K

2017-04-01

This study aimed to investigate the effect of tea catechin (C) and 4 of its derivatives on the Pacific white shrimp PPO inhibition and melanosis during refrigerated storage. Epigallocatechin gallate (EGCG) exhibited the highest inhibition towards PPO, followed by C. Inhibitory activity of all compounds tested was in a dose dependent manner (0.1-2.0 mM). Based on activity staining, EGCG most effectively inhibited PPO. For inhibition kinetic studies, C and epicatechin (EC) showed uncompetitive type, whereas epicatechin gallate (ECG), epigallocatechin (EGC) and EGCG exhibited mixed type inhibition. When whole shrimps were treated with EGCG solution at various concentrations (0.25-0.75%), those treated with 0.5 or 0.75% EGCG had lower melanosis scores throughout storage for 10 days at 4 °C, compared with the control and the 1.25% sodium metabisulfite treated samples ( P  < 0.05). Therefore, EGCG could be used as a potential inhibitor for melanosis in raw Pacific white shrimp during refrigerated storage.

Identification and antioxidant properties of polyphenols in lotus seed epicarp at different ripening stages.

PubMed

Liu, Ying; Ma, Shuang-shuang; Ibrahim, S A; Li, Er-hu; Yang, Hong; Huang, Wen

2015-10-15

In this study, polyphenols from lotus seed epicarp (PLSE) at three different ripening stages were purified by column chromatography and identified by RP-HPLC and HPLC-ESI-MS(2). The antioxidant activities of PLSE were also investigated. We found that the contents of PLSE at the green ripening stage, half ripening stage and full ripening stage are 13.08%, 10.95% and 6.73% respectively. The levels of catechin, epicatechin, hyperoside, and isoquercitrin in PLSE at the three different ripening stages were different. Moreover, the amounts of catechin and epicatechin decreased, while the contents of hyperoside and isoquercitrin increased as the seed ripened. We found that PLSE at three different ripening stages had good scavenging abilities on DPPH and ABTS(+) radicals. However, the scavenging ability decreased with maturation. Our results may be valuable with regard to the utilization of lotus seed epicarp as a functional food material. Copyright © 2015 Elsevier Ltd. All rights reserved.

Factors influencing the antifolate activity of synthetic tea-derived catechins.

PubMed

Sáez-Ayala, Magalí; Fernández-Pérez, María Piedad; Chazarra, Soledad; Mchedlishvili, Nani; Tárraga-Tomás, Alberto; Rodríguez-López, José Neptuno

2013-07-16

Novel tea catechin derivatives have been synthesized, and a structure-activity study, related to the capacity of these and other polyphenols to bind dihydrofolate reductase (DHFR), has been performed. The data showed an effective binding between all molecules and the free enzyme, and the dissociation constants of the synthetic compounds and of the natural analogues were on the same order. Polyphenols with a catechin configuration were better DHFR inhibitors than those with an epicatechin configuration. Antiproliferative activity was also studied in cultured tumour cells, and the data showed that the activity of the novel derivatives was higher in catechin isomers. Derivatives with a hydroxyl group para on the ester-bonded gallate moiety presented a high in vitro binding to DHFR, but exhibited transport problems in cell culture due to ionization at physiologic pHs. The impact of the binding of catechins to serum albumin on their biological activity was also evaluated. The information provided in this study could be important for the design of novel medicinal active compounds derived from tea catechins. The data suggest that changes in their structure to avoid serum albumin interactions and to facilitate plasmatic membrane transport are essential for the intracellular functions of catechins.

Formaldehyde condensation products of model phenols for conifer bark tannins

Treesearch

Richard W. Hemingway; Gerald W. McGraw

1978-01-01

Gel permeation chromatography of the condensation products of phenols and formaldehyde proved effective in understanding the reactions of condensed tannins with formaldehyde. Rates of condensation of phloroglucinols, resorcinols, catechols, (+)catechins, and (-)epicatechin were examined to determine if methylol-tannins from southern pine bark could be prepared as resin...

Formaldehyde condensation products of model phenols for conifer bark tannins

Treesearch

R.W. Hemingway; G.W. McGraw

1978-01-01

Gel permeation chromatograpy of the condensation products of phenols and formaldehyde proved effective in understanding the reactions of condensed tannins with formaldehyde. Rates of condensation of phloroglucinols, resorcinols, catechols, (+)catechin, and (-)epicatechin were examined to determine if methylol-tannins from southern pine bark could be prepared as resin...

Urinary Biomarkers of Catechins and Risk of Hepatocellular Carcinoma in the Shanghai Cohort Study

PubMed Central

Butler, Lesley M.; Huang, Joyce Yongxu; Wang, Renwei; Lee, Mao-Jun; Yang, Chung S.; Gao, Yu-Tang; Yuan, Jian-Min

2015-01-01

Dietary catechins are phytochemicals with both antioxidative and prooxidative stress properties. Green tea is a major source of catechins and may be associated with hepatocellular carcinoma (HCC) risk, but the catechin-HCC relationship has not been evaluated using a biomarker-based approach. A nested case-control study of HCC (211 cases and 1,067 matched controls) was conducted within the Shanghai Cohort Study, which enrolled 18,244 men between 1986 and 1989. Concentrations of specific catechins, including epicatechin, epigallocatechin (EGC), and 4′-O-methyl-epigallocatechin, were measured in urine specimens that had been collected prior to HCC diagnosis. None of the catechins measured were associated with HCC risk. In stratified analyses, there was a statistically significant trend for an association of higher urinary EGC with increased HCC risk among subjects with positive serology for hepatitis B surface antigen (P for trend = 0.02). This positive EGC-HCC association became stronger for hepatitis B surface antigen–positive persons who also had low serum retinol levels (for detectable levels vs. undetectable levels, odds ratio = 2.62, 95% confidence interval: 1.25, 5.51). There was no evidence supporting a protective role of catechins in the development of HCC. Instead, exposure to high levels of catechins may increase the risk of developing HCC for high-risk individuals. PMID:25713334

Antioxidants from the bark of Burkea africana, an African medicinal plant.

PubMed

Mathisen, Elin; Diallo, Drissa; Andersen, Øyvind M; Malterud, Karl Egil

2002-03-01

The bark of the tree Burkea africana is used medicinally in large areas of sub-Saharan Africa. The constituents responsible for its putative activity are not well known. We have investigated the bark of B. africana for antioxidant and radical scavenging activity. A hydroethanol bark extract showed high activity, and most of this activity was located in semipolar fractions of the extract. From chromatographic purification and spectroscopical structure studies, we conclude that the active constituents are proanthocyanidins. Two major components appear to be fisetinidol-(4alpha- --> 8)-catechin 3-gallate and bis-fisetinidol-(4alpha- --> 6, 4alpha- --> 8)-catechin 3-gallate. The latter compound is a new natural product. Smaller amounts of monomeric flavan-3-ols (catechin, epicatechin and fisetinidol) were also found. Copyright 2002 John Wiley & Sons, Ltd.

Bactericidal catechins damage the lipid bilayer.

PubMed

Ikigai, H; Nakae, T; Hara, Y; Shimamura, T

1993-04-08

The mode of antibacterial action of, the green tea (Camellia sinensis) extracts, (-)-epigallocatechin gallate (EGCg) and (-)-epicatechin (EC) was investigated. Strong bactericidal EGCg caused leakage of 5,6-carboxyfluorescein from phosphatidylcholine liposomes (PC), but EC with very weak bactericidal activity caused little damage to the membrane. Phosphatidylserine and dicetyl phosphate partially protected the membrane from EGCg-mediated damage when reconstituted into the liposome membrane with PC. EGCg, but not EC, caused strong aggregation and NPN-fluorescence quenching of PC-liposomes and these actions were markedly lowered in the presence of negatively charged lipids. These results show that bactericidal catechins primarily act on and damage bacterial membranes. The observation that Gram-negative bacteria are more resistant to bactericidal catechins than Gram-positive bacteria can be explained to some extent by the presence of negatively charged lipopolysaccharide.

[Effect of tea extracts, catechin and caffeine against type-I allergic reaction].

PubMed

Shiozaki, T; Sugiyama, K; Nakazato, K; Takeo, T

1997-07-01

The antiallergic effects of green tea, oolong tea, and black tea extracts by hot water were examined. These extracts inhibited the passive cutaneous anaphylaxis (PCA) reaction of rat after oral administration. Three tea catechins, (--)-epigallocatechin (EGC), (--)-epicatechin gallate (ECg), and (--)-epigallocatechin gallate (EGCg) isolated from green tea showed stronger inhibitory effects than that of a green tea extract on the PCA reaction. The inhibitory effects of EGC and EGCg on the PCA reaction were greater than that of ECg. Caffeine also showed a inhibitory effect on the PCA reaction. These results indicate that tea could provide a significant protection against the type-I allergic reaction. These findings also suggest that tea catechins and caffeine play an important role in having an inhibitory effect on the type-I allergic reaction.

Chocolate and cardiovascular health: is it too good to be true?

PubMed

Ariefdjohan, Merlin W; Savaiano, Dennis A

2005-12-01

Recent findings indicate that cocoa and chocolate, when processed appropriately, may contain relatively large amounts of flavonoids, particularly catechin and epicatechin. We review the benefits of these flavonoids, specifically with regard to cardiovascular health, and raise several unresolved issues that suggest the need for additional research and product development in this area.

Annotation of Different Dehydrocatechin Oligomers by MS/MS and Their Occurrence in Black Tea.

PubMed

Verloop, Annewieke J W; Gruppen, Harry; Vincken, Jean-Paul

2016-08-03

Dehydrocatechins (DhC's), oligomeric oxidation products of (epi)catechins, were formed in model incubations of epicatechin with mushroom tyrosinase. DhC oligomers up to tetramers were detected by reversed-phase ultrahigh-performance liquid chromatography mass spectrometry (RP-UHPLC-MS) analysis. Measurements with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) showed formation of oligomers up to at least 15 catechin subunits. Isomeric DhC's were obtained, and a method based on MS(2) fragment ratios was set up to distinguish between the different interflavanic configurations of the isomers. In the model incubation, 8 dehydrodicatechins (DhC2's) and 22 dehydrotricatechins (DhC3's) were tentatively annotated by their MS(2) signature fragments. Three different interflavanic configuration types were determined for the DhC2's. DhC2's and DhC3's were shown to occur in a black tea extract for the first time. For the DhC2's, at least two isomeric types, i.e., DhC β and DhC ε, could be annotated in black tea.

Flavanol binding of nuclei from tree species.

PubMed

Feucht, W; Treutter, D; Polster, J

2004-01-01

Light microscopy was used to examine the nuclei of five tree species with respect to the presence of flavanols. Flavanols develop a blue colouration in the presence of a special p-dimethylaminocinnamaldehyde (DMACA) reagent that enables those nuclei loaded with flavanols to be recognized. Staining of the nuclei was most pronounced in both Tsuga canadensis and Taxus baccata, variable in Metasequoia glyptostroboides, faint in Coffea arabica and minimal in Prunus avium. HPLC analysis showed that the five species contained substantial amounts of different flavanols such as catechin, epicatechin and proanthocyanidins. Quantitatively, total flavanols were quite different among the species. The nuclei themselves, as studied in Tsuga seed wings, were found to contain mainly catechin, much lower amounts of epicatechin and traces of proanthocyanidins. Blue-coloured nuclei located centrally in small cells were often found to maximally occupy up to 90% of a cell's radius, and the surrounding small rim of cytoplasm was visibly free of flavanols. A survey of 34 gymnosperm and angiosperm species indicated that the first group has much higher nuclear binding capacities for flavanols than the second group.

Antisecretory activity from the flowers of Chiranthodendron pentadactylon and its flavonoids on intestinal fluid accumulation induced by Vibrio cholerae toxin in rats.

PubMed

Velázquez, Claudia; Calzada, Fernando; Esquivel, Baldomero; Barbosa, Elizabeth; Calzada, Samuel

2009-12-10

The flowers of Chiranthodendron pentadactylon Larreat. (Sterculiaceae) has been traditionally used as folk medicine in Mexico for the treatment of gastrointestinal disorders such as diarrhea and dysentery. This study aimed to assess the antisecretory activity which supports the therapeutic use of Chiranthodendron pentadactylon and its flavonoids to treat diarrhea. The methanol extract of Chiranthodendron pentadactylon, subsequent fractions, and flavonoids were evaluated on cholera toxin-induced intestinal secretion in rat jejunal loops model. Three antisecretory flavonoids were isolated by bioassay-guided purification, namely, isoquercitrin 3, (+)-catechin 4 and (-)-epicatechin 5. Among them, epicatechin exhibited the most potent antisecretory activity with ID(50) of 8.3 microM/kg. Its potency was close that of to loperamide (ID(50) 6.1 microM/kg), drug used as control. Isoquercitrin (ID(50) 19.2 microM/kg) and catechin (ID(50) 51.7 microM/kg) showed moderate and weak activity, respectively. The results of the present study lend some support to the anecdotal report for the traditional use of the flowers of Chiranthodendron pentadactylon in the control of dysentery.

Chlorogenic acid, anthocyanin and flavan-3-ol biosynthesis in flesh and skin of Andean potato tubers (Solanum tuberosum subsp. andigena).

PubMed

Valiñas, Matías Ariel; Lanteri, María Luciana; Ten Have, Arjen; Andreu, Adriana Balbina

2017-08-15

Natural variation of Andean potato was used to study the biosynthesis of phenolic compounds. Levels of phenolic compounds and corresponding structural gene transcripts were examined in flesh and skin of tubers. Phenolic acids, mainly chlorogenic acid (CGA), represent the major compounds, followed by anthocyanins and flavan-3-ols. High-anthocyanin varieties have high levels of CGA. Both metabolite and transcript levels were higher in skin than in flesh and showed a good correspondence. Two hydroxycinnamoyl-CoA transferases (HCT/HQT) have been involved in CGA production, of which HCT reflects CGA levels. Catechin was found in pigmented tissues whereas epicatechin was restricted to tuber skin. Transcripts of leucoanthocyanidin reductase (LCR), which generates catechin, could not be detected. Anthocyanidin reductase (ANR) transcripts, the enzyme responsible for epicatechin production, showed similar levels among samples. These data suggest that the biosynthesis of flavan-3-ols in potato tuber would require ANR but not LCR and that an epimerization process is involved. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of free, esterified, glycosylated and insoluble-bound phenolics composition in the edible part of araticum fruit (Annona crassiflora Mart.) and its by-products by HPLC-ESI-MS/MS.

PubMed

Arruda, Henrique Silvano; Pereira, Gustavo Araujo; de Morais, Damila Rodrigues; Eberlin, Marcos Nogueira; Pastore, Glaucia Maria

2018-04-15

Phenolics present in the free, esterified, glycosylated and insoluble-bound forms of araticum pulp, peel and seed were for the first time characterized and quantified using HPLC-ESI-MS/MS. Levels of total phenolics, flavonoids, condensed tannins and antioxidant activities from araticum fruit followed the order peel > pulp > seed. Overall, insoluble-bound and esterified phenolics were the dominant forms of phenolics from araticum fruit parts and the highest contributors to their antioxidant activities. Extracts were found to contain contrasting levels of phenolics that were specific to each fruit part. From 10 phenolics quantified in araticum fruit, catechin and epicatechin were the major ones from pulp and peel, whereas seed displayed caffeic acid, catechin and epicatechin as its main phenolics. Araticum fruit was found to provide a good source of phenolics, and the full exploitation of this fruit may find applications in the food, cosmetic and pharmaceutical industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Direct anthelmintic effects of condensed tannins from diverse plant sources against Ascaris suum.

PubMed

Williams, Andrew R; Fryganas, Christos; Ramsay, Aina; Mueller-Harvey, Irene; Thamsborg, Stig M

2014-01-01

Ascaris suum is one of the most prevalent nematode parasites in pigs and causes significant economic losses, and also serves as a good model for A. lumbricoides, the large roundworm of humans that is ubiquitous in developing countries and causes malnutrition, stunted growth and compromises immunity to other pathogens. New treatment options for Ascaris infections are urgently needed, to reduce reliance on the limited number of synthetic anthelmintic drugs. In areas where Ascaris infections are common, ethno-pharmacological practices such as treatment with natural plant extracts are still widely employed. However, scientific validation of these practices and identification of the active compounds are lacking, although observed effects are often ascribed to plant secondary metabolites such as tannins. Here, we extracted, purified and characterised a wide range of condensed tannins from diverse plant sources and investigated anthelmintic effects against A. suum in vitro. We show that condensed tannins can have potent, direct anthelmintic effects against A. suum, as evidenced by reduced migratory ability of newly hatched third-stage larvae and reduced motility and survival of fourth-stage larvae recovered from pigs. Transmission electron microscopy showed that CT caused significant damage to the cuticle and digestive tissues of the larvae. Furthermore, we provide evidence that the strength of the anthelmintic effect is related to the polymer size of the tannin molecule. Moreover, the identity of the monomeric structural units of tannin polymers may also have an influence as gallocatechin and epigallocatechin monomers exerted significant anthelmintic activity whereas catechin and epicatechin monomers did not. Therefore, our results clearly document direct anthelmintic effects of condensed tannins against Ascaris and encourage further in vivo investigation to determine optimal strategies for the use of these plant compounds for the prevention and/or treatment of ascariosis.

Direct Anthelmintic Effects of Condensed Tannins from Diverse Plant Sources against Ascaris suum

PubMed Central

Williams, Andrew R.; Fryganas, Christos; Ramsay, Aina; Mueller-Harvey, Irene; Thamsborg, Stig M.

2014-01-01

Ascaris suum is one of the most prevalent nematode parasites in pigs and causes significant economic losses, and also serves as a good model for A. lumbricoides, the large roundworm of humans that is ubiquitous in developing countries and causes malnutrition, stunted growth and compromises immunity to other pathogens. New treatment options for Ascaris infections are urgently needed, to reduce reliance on the limited number of synthetic anthelmintic drugs. In areas where Ascaris infections are common, ethno-pharmacological practices such as treatment with natural plant extracts are still widely employed. However, scientific validation of these practices and identification of the active compounds are lacking, although observed effects are often ascribed to plant secondary metabolites such as tannins. Here, we extracted, purified and characterised a wide range of condensed tannins from diverse plant sources and investigated anthelmintic effects against A. suum in vitro. We show that condensed tannins can have potent, direct anthelmintic effects against A. suum, as evidenced by reduced migratory ability of newly hatched third-stage larvae and reduced motility and survival of fourth-stage larvae recovered from pigs. Transmission electron microscopy showed that CT caused significant damage to the cuticle and digestive tissues of the larvae. Furthermore, we provide evidence that the strength of the anthelmintic effect is related to the polymer size of the tannin molecule. Moreover, the identity of the monomeric structural units of tannin polymers may also have an influence as gallocatechin and epigallocatechin monomers exerted significant anthelmintic activity whereas catechin and epicatechin monomers did not. Therefore, our results clearly document direct anthelmintic effects of condensed tannins against Ascaris and encourage further in vivo investigation to determine optimal strategies for the use of these plant compounds for the prevention and/or treatment of ascariosis. PMID:24810761

Catechin Composition and Antioxidant Activity of Black Teas in Relation to Brewing Time.

PubMed

Koch, Wojciech; Kukula-Koch, Wirginia; Głowniak, Kazimierz

2017-11-01

Black tea infusions are one of the most popular beverages across the world. Their extract composition depends on several factors, brewing time being one of the most important determinants. The aim of the present study was to determine the catechin composition of different black tea infusions using a validated LC electrospray ionization time-of-flight MS method. Additionally, total phenolic content (TPC) and antioxidant activity of infusions were evaluated using Folin-Ciocalteu reagent and stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). An optimized LC-MS method enabled the precise identification of the studied catechins [epicatechin (EC), EC gallate (ECG), epigallocatechin (EGC), and epigallocatechin-3-gallate (EGCG)] and gallic acid (GA). The major catechin in all investigated teas was EGC (25.6 mg/100 cm3 after 4 min of brewing). EC was present at the lowest concentration in all extracts. TPC and antiradical scavenging activity were in a good agreement with catechins and GA content. In general, the longer the brewing time, the higher the concentration of catechin, TPC, and antioxidant activity values. However, it should be noted that after 2 min brewing, most phenolics had already been extracted, and extract composition did not significantly change at a prolonged extraction time.

Tea polyphenols dominate the short-term tea (Camellia sinensis) leaf litter decomposition*

PubMed Central

Fan, Dong-mei; Fan, Kai; Yu, Cui-ping; Lu, Ya-ting; Wang, Xiao-chang

2017-01-01

Polyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months. The release patterns of nitrogen, potassium, calcium, and magnesium were also determined. The decomposition pattern of tea leaf litter could be described by a two-phase decomposition model, and the polyphenol/N ratio effectively regulated the degradation process. Most of the catechins decreased dramatically within two months; gallic acid (GA), catechin gallate (CG), and gallocatechin (GC) were faintly detected, while others were outside the detection limits by the end of the experiment. These results demonstrated that tea polyphenols transformed quickly and catechins had an effect on the individual conversion rate. The nutrient release pattern was different from other plants which might be due to the existence of tea polyphenols. PMID:28124839

Tea polyphenols dominate the short-term tea (Camellia sinensis) leaf litter decomposition.

PubMed

Fan, Dong-Mei; Fan, Kai; Yu, Cui-Ping; Lu, Ya-Ting; Wang, Xiao-Chang

Polyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months. The release patterns of nitrogen, potassium, calcium, and magnesium were also determined. The decomposition pattern of tea leaf litter could be described by a two-phase decomposition model, and the polyphenol/N ratio effectively regulated the degradation process. Most of the catechins decreased dramatically within two months; gallic acid (GA), catechin gallate (CG), and gallocatechin (GC) were faintly detected, while others were outside the detection limits by the end of the experiment. These results demonstrated that tea polyphenols transformed quickly and catechins had an effect on the individual conversion rate. The nutrient release pattern was different from other plants which might be due to the existence of tea polyphenols.

Inhibition of Catalase by Tea Catechins in Free and Cellular State: A Biophysical Approach

PubMed Central

Pal, Sandip; Dey, Subrata Kumar; Saha, Chabita

2014-01-01

Tea flavonoids bind to variety of enzymes and inhibit their activities. In the present study, binding and inhibition of catalase activity by catechins with respect to their structure-affinity relationship has been elucidated. Fluorimetrically determined binding constants for (−)-epigallocatechin gallate (EGCG) and (−)-epicatechin gallate (ECG) with catalase were observed to be 2.27×106 M−1 and 1.66×106 M−1, respectively. Thermodynamic parameters evidence exothermic and spontaneous interaction between catechins and catalase. Major forces of interaction are suggested to be through hydrogen bonding along with electrostatic contributions and conformational changes. Distinct loss of α-helical structure of catalase by interaction with EGCG was captured in circular dichroism (CD) spectra. Gallated catechins demonstrated higher binding constants and inhibition efficacy than non-gallated catechins. EGCG exhibited maximum inhibition of pure catalase. It also inhibited cellular catalase in K562 cancer cells with significant increase in cellular ROS and suppression of cell viability (IC50 54.5 µM). These results decipher the molecular mechanism by which tea catechins interact with catalase and highlight the potential of gallated catechin like EGCG as an anticancer drug. EGCG may have other non-specific targets in the cell, but its anticancer property is mainly defined by ROS accumulation due to catalase inhibition. PMID:25025898

[Antibacterial and anti-hemolysin activities of tea catechins and their structural relatives].

PubMed

Toda, M; Okubo, S; Ikigai, H; Shimamura, T

1990-03-01

Among catechins tested, (-)epigallocatechin (EGC), (-)epicatechin gallate (ECg), (-) epigallocatechin gallate (EGCg) inhibited the growth of Staphylococcus aureus, Vibrio cholerae O1 classical Inaba 569B and El Tor Inaba V86. S. aureus was more sensitive than V. cholerae O1 to these compounds. EGCg showed also a bactericidal activity against V. cholerae O1 569B. Pyrogallol showed a stronger antibacterial activity against S. aureus and V. cholerae O1 than tannic and gallic acid. Rutin or caffein had no effect on them. ECg and EGCg showed the most potent anti-hemolysin activity against S. aureus alpha-toxin, Vibrio parahaemolyticus thermostable direct hemolysin (Vp-TDH) and cholera hemolysin. Among catechin relatives, only tannic acid had a potent anti-hemolysin activity against alpha-toxin. These results suggest that the catechol and pyrogallol groups are responsible for the antibacterial and bactericidal activities, while the conformation of catechins might play an important role in the anti-hemolysin activity.

Implications of the fluorescence for the conformational analysis of polymeric profisetinidins and procyanidins

Treesearch

Carin A. Helfer; Joo-Sang Sun; Mark A. Matties; Wayne L. Mattice; Richard W. Hemingway; Jan P. Steynberg; Lisa A. Kelly

1995-01-01

The common monomeric units in the polymeric proeyanidins are catechin and epicatechin, which have a hydroxyl group at C(5). This hydroxyl group is absent in the profisetinidins. The fluorescence properties have been characterized for the profisetinidin monomer and dimers, and compared with previous results for the procyanidins. There is a measurable heterogeneity in...

Implications of the fluorescence for the conformational analysis of polymeric profisentinidins and procyanidins

Treesearch

Carin A. Heifer; Joo-Sang Sun; Mark A. Matties; Wayne L. Mattice; Richard W. Hemingway; Jan P. Steynberg; Lisa A. Kelly

1995-01-01

The common monomeric units in the polymeric procyanidins are catechin and epicatechin, which have a hydroxyl group at C(5). this hydroxyl group is absent in the profisetinidins. The fluorescence properties have been characterized for the profisentinidin monomer and dimers, and compared with previous results for the procyanidins. There is a measurable heterogeneity in...

Novel Antihypertensive Prodrug from Grape Seed Proanthocyanidin Extract via Acid-Mediated Depolymerization in the Presence of Captopril: Synthesis, Process Optimization, and Metabolism in Rats.

PubMed

Cui, Can; Shi, Ailong; Bai, Shuang; Yan, Pengyu; Li, Qing; Bi, Kaishun

2018-04-11

Grape seed extract contains a high content of proanthocyanidins that can be depolymerized into C-4-substituted (epi)catechin derivatives in the presence of nucleophiles. However, the biological and medicinal values of depolymerization products have been rarely investigated. Recently, we developed a novel depolymerization product (-)-epicatechin-4β- S-captopril methyl ester (ECC) derived from the reaction of grape seed proanthocyanidin extract with captopril in the presence of acidified methanol. A central composite design was employed to select the most appropriate depolymerization temperature and time to obtain the target product ECC with a high yield. A total of 16 metabolites of ECC in rat urine, feces, and plasma were identified using liquid chromatography quadrupole time-of-flight tandem mass spectrometry. The in vivo results suggested that ECC could release captopril methyl ester and epicatechin, followed by the generation of further metabolites captopril and epicatechin sulfate conjugates. Therefore, ECC may be used as a potential prodrug with synergistic or additive hypotensive effects.

Preparation of dimeric procyanidins B1, B2, B5, and B7 from a polymeric procyanidin fraction of black chokeberry ( Aronia melanocarpa ).

PubMed

Esatbeyoglu, Tuba; Winterhalter, Peter

2010-04-28

A semisynthetic approach has been used for the preparative formation of dimeric procyanidins B1, B2, B5, and B7. As starting material for the semisynthesis, polymeric procyanidins from black chokeberry were applied. These polymers were found to consist almost exclusively of (-)-epicatechin units. Under acidic conditions the interflavanoid linkages of the polymeric procyanidins are cleaved and the liberated (-)-epicatechin can react with nucleophiles, such as (+)-catechin or (-)-epicatechin. In this way, the polymeric procyanidins are degraded while dimeric procyanidins are formed. During this reaction only dimeric procyanidins are formed that contain (-)-epicatechin in the upper unit, that is, B1 [(-)-EC-4beta-->8-(+)-C)], B2 [(-)-EC-4beta-->8-(-)-EC], B5 [(-)-EC-4beta-->6-(-)-EC], and B7 [(-)-EC-4beta-->6-(+)-C]. The reaction mixtures of the semisynthesis can be successfully fractionated with high-speed countercurrent chromatography (HSCCC), and it is possible to isolate pure procyanidins B1, B2, B5, and B7 on a preparative scale.

Antimicrobial and antiviral activities of polyphenolics from Cocos nucifera Linn. (Palmae) husk fiber extract.

PubMed

Esquenazi, Daniele; Wigg, Marcia D; Miranda, Mônica M F S; Rodrigues, Hugo M; Tostes, João B F; Rozental, Sonia; da Silva, Antonio J R; Alviano, Celuta S

2002-12-01

The decoction of Cocos nucifera L. husk fiber has been used in northeastern Brazil traditional medicine for treatment of diarrhea and arthritis. Water extract obtained from coconut husk fiber and fractions from adsorption chromatography revealed antimicrobial activity against Staphylococcus aureus. The crude extract and one of the fractions rich in catechin also showed inhibitory activity against acyclovir-resistant herpes simplex virus type 1 (HSV-1-ACVr). All fractions were inactive against the fungi Candida albicans, Fonsecaea pedrosoi and Cryptococcus neoformans. Catechin and epicatechin together with condensed tannins (B-type procyanidins) were demonstrated to be the components of the water extract.

Rapid, direct determination of polyphenols in tea by reversed-phase column liquid chromatography.

PubMed

Ding, M; Yang, H; Xiao, S

1999-07-23

Column liquid chromatography on a C18-bonded silica column with water-methanol-acetic acid as eluent was used to determine polyphenols and caffeine in tea. Without any pretreatment, catechin, epicatechin gallate, epigallocatechin gallate, epigallocatechin, epicatechin and caffeine were separated successfully within 15 min. The detection limits (S/N = 3) of polyphenols studied were 1.8-24 mg/l at a detection wavelength 270 nm. The linear range of the peak area calibration curves for the analytes were over two orders of magnitude with a correlation coefficient of 0.996-0.999. Using this method, some Chinese tea samples were analyzed with a good reproducibility (RSD are below 5%).

Separation of catechin constituents from five tea cultivars using high-speed counter-current chromatography.

PubMed

Kumar, N Savitri; Rajapaksha, Maheshinie

2005-08-12

Catechins were extracted from five different tea (Camellia sinensis L.) cultivars. High-speed counter-current chromatography was found to be an efficient method for the separation of seven catechins from the catechin extracts. High-performance liquid chromatography was used to assess the purity of the catechins isolated. Epigallocatechin gallate (EGCG), epicatechin gallate (ECG) and epigallocatechin (EGC) of high purity (91-99%) were isolated in high yield after a single high-speed counter-current chromatography run. The two-phase solvent mixtures used for the separation of the catechin extracts were hexane:ethyl acetate:methanol:water (1:6:1:6 for TRI 2023); (1:7:1:7 for TRI 2025 and TRI 2043); (1:5:1:5 for TRI 3079) and (1:6.5:1:6.5 for TRI 4006). Fresh tea shoots from the tea cultivar TRI 2023 (150 g) gave 440 mg of 96% pure EGCG while TRI 2025 (235 g) gave 347 mg of 99% pure EGCG and 40 mg of 97% ECG, and TRI 3079 (225 g) gave 432 mg of 97% pure EGCG and 32 mg of 96% pure ECG. Tea cultivar TRI 4006 (160 g) gave EGCG (272 mg, 96% pure) and EGC (104 mg, 90% pure). 1H and 13C NMR chemical shifts for catechin gallate (CG), EGC, ECG, EGCG and epigallocatechin 3,5-di-O-gallate (EGCDG) in CD3OD were also recorded.

Analysis of CYP3A inhibitory components of star fruit (Averrhoa carambola L.) using liquid chromatography-mass spectrometry.

PubMed

Hosoi, Shinzo; Shimizu, Eri; Arimori, Kazuhiko; Okumura, Manabu; Hidaka, Muneaki; Yamada, Mitsuko; Sakushima, Akiyo

2008-07-01

In this study, we analyzed the CYP3A inhibitory components of star fruit Averrhoa carambola L., using liquid chromatography-mass spectrometry (LC-MS). The stereoisomer of procyanidin B1 and B2 and/or the trimer consisting of catechin and/or epicatechin were suggested to be potent inhibitory components.

Condensed tannins. Base-catalysed reactions of polymeric procyanidins with phloroglucinol: Intramolecular rearrangements

Treesearch

Peter E. Laks; Richard W. Hemingway; Anthony H. Conner

1987-01-01

Reactions of polymeric procyanidins with phloroglucinol at pH 12.0 and temperatures of 23 or 50°C gave epicatechin-(4β)-phloroglucinol (7), by cleavage of the interflavanoid bond between procyanidin units with subsequent addition of phloroglucinol, and (+)-catechin from the terminal unit. The phloroglucinol adduct (7) rearranged to an enolic form of 8-(3,4-...

HPLC determination of phenolic acids, flavonoids and juglone in walnut leaves.

PubMed

Nour, Violeta; Trandafir, Ion; Cosmulescu, Sina

2013-10-01

A high-performance liquid chromatographic method with gradient elution and diode-array detection was developed to quantify free phenolic acids (gallic, vanillic, chlorogenic, caffeic, syringic, p-coumaric, ferulic, sinapic, salycilic, elagic and trans-cinnamic), flavonoids (catechin, epicatechin, rutin, myricetin and quercetin) and juglone in walnut leaves. Chromatographic separation was performed on a Hypersil Gold C18 column (5 µm particle size, 250 × 4.6 mm) and detection was conducted at three different wavelengths (254, 278 and 300 nm) according to the absorption maxima of the analyzed compounds. Validation procedures were conducted and the method was proven to be precise, accurate and sensitive. The developed method has been applied to analyze walnut leaves samples from nine different cultivars, with the same agricultural, geographical and climatic conditions. The experimental results revealed high concentrations of myricetin, catechin hydrate and rutin, and low concentrations of quercetin and epicatechin aglycones. Ellagic acid was established as the dominating phenolic acid of walnut leaves, followed by trans-cinnamic, chlorogenic and caffeic acids. Juglone content varied between 44.55 and 205.12 mg/100 g fresh weight. Significant differences were detected among cultivars for the concentration levels of phenolics.

Caffeic acid, tyrosol and p-coumaric acid are potent inhibitors of 5-S-cysteinyl-dopamine induced neurotoxicity.

PubMed

Vauzour, David; Corona, Giulia; Spencer, Jeremy P E

2010-09-01

Parkinson's disease is characterized by a progressive and selective loss of dopaminergic neurons in the substantia nigra. Recent investigations have shown that conjugates such as the 5-S-cysteinyl-dopamine, possess strong neurotoxicity and may contribute to the underlying progression of the disease pathology. Although the neuroprotective actions of flavonoids are well reported, that of hydroxycinnamates and other phenolic acids is less established. We show that the hydroxycinnamates caffeic acid and p-coumaric acid, the hydroxyphenethyl alcohol, tyrosol, and a Champagne wine extract rich in these components protect neurons against injury induced by 5-S-cysteinyl-dopamine in vitro. The protection induced by these polyphenols was equal to or greater than that observed for the flavonoids, (+)-catechin, (-)-epicatechin and quercetin. For example, p-coumaric acid evoked significantly more protection at 1muM (64.0+/-3.1%) than both (-)-epicatechin (46.0+/-4.1%, p<0.05) and (+)-catechin (13.1+/-3.0%, p<0.001) at the same concentration. These data indicate that hydroxycinnamates, phenolic acids and phenolic alcohol are also capable of inducing neuroprotective effects to a similar extent to that seen with flavonoids. Copyright © 2010. Published by Elsevier Inc.

Alkaloid and polyphenol analysis by HPLC in green and black tea powders and their potential use as additives in ruminant diets

NASA Astrophysics Data System (ADS)

Ramdani, Diky; Chaudhry, Abdul S.; Seal, Chris J.

2018-02-01

We used HPLC to examine the bioactive compounds such as alkaloids and polyphenols in green and black tea powders and their use as potential additives in ruminant diets. Caffeine was the highest alkaloid in both green and black teas. Green tea had significantly higher concentrations of alkaloids and catechins but lower theaflavins than black tea. Epigallocatechin gallate, epicatechin gallate and epigallocatechin were the major catechins in green tea while theaflavin-3, 3'-digallate and theaflavin-3-gallate were the major theaflavins in black tea. Tea powders in ruminant diets decreased in vitro rumen ammonia and methane production without affecting volatile fatty acid profiles and the degradability of the diets. The tea powders containing variable amounts of alkaloids, catechins and theaflavins can potentially be used to decrease rumen ammonia and methane productions without any detrimental effect on rumen functions in vitro and perhaps ruminant productive efficiency.

Green tea extracts reduce leukocyte cell-Derived chemotaxin 2 and selenoprotein P levels in the livers of C57BL/6J mice fed a high-fat diet.

PubMed

Onishi, Shintaro; Kitazawa, Hidefumi; Meguro, Shinichi; Tokimitsu, Ichiro

2018-05-31

Epidemiological studies suggest that green tea extracts (GTEs), including catechins such as epigallocatechin gallate and epicatechin gallate, have a beneficial effect on obesity, hyperglycemia, insulin resistance, endothelial dysfunction, and inflammation. Although several studies have shown that catechins directly modulate the cellular and molecular alterations in the liver tissue, the contributions of indirect mechanisms underlying these systemic effects of catechins remain unclear. In this study, we report that, in the C57BL/6J mouse liver, GTEs reduce high-fat diet-induced increases in the levels of hepatokines, liver-derived secretary proteins such as leukocyte cell-derived chemotaxin 2 and selenoprotein P production, which have been shown to induce systemic adverse effects, including several metabolic diseases. These findings suggest that the systemic effects of GTEs involve the regulation of hepatokine production as an indirect mechanism.

Dietary (−)-epicatechin as a potent inhibitor of βγ-secretase amyloid precursor protein processing☆

PubMed Central

Cox, Carla J.; Choudhry, Fahd; Peacey, Eleanor; Perkinton, Michael S.; Richardson, Jill C.; Howlett, David R.; Lichtenthaler, Stefan F.; Francis, Paul T.; Williams, Robert J.

2015-01-01

Flavonoids, a group of dietary polyphenols have been shown to possess cognitive health benefits. Epidemiologic evidence suggests that they could play a role in risk reduction in dementia. Amyloid precursor protein processing and the subsequent generation of amyloid beta (Aβ) are central to the pathogenesis of Alzheimer's disease, as soluble, oligomeric Aβ is thought to be the toxic species driving disease progression. We undertook an in vitro screen to identify flavonoids with bioactivity at βγ-mediated amyloid precursor protein processing, which lead to identification of a number of flavonoids bioactive at 100 nM. Because of known bioavailability, we investigated the catechin family further and identified epigallocatechin and (−)-epicatechin as potent (nanomolar) inhibitors of amyloidogenic processing. Supporting this finding, we have shown reduced Aβ pathology and Aβ levels following short term, a 21-day oral delivery of (−)-epicatechin in 7-month-old TASTPM mice. Further, in vitro mechanistic studies suggest this is likely because of indirect BACE1 inhibition. Taken together, our results suggest that orally delivered (−)-epicatechin may be a potential prophylactic for Alzheimer's disease. PMID:25316600

Radiation induced chemical changes of phenolic compounds in strawberries

NASA Astrophysics Data System (ADS)

Breitfellner, F.; Solar, S.; Sontag, G.

2003-06-01

In unirradiated strawberries four phenolic acids (gallic acid, p-coumaric acid, caffeic acid and 4-hydroxybenzoic acid), the flavonoids (+)-catechin, (-)-epicatechin and glycosides from kaempferol and quercetin were determined by reversed phase chromatography with diode array detection. Characteristic linear dose/concentration relationships were found for 4-hydroxybenzoic acid and two unidentified compounds. One of them may be usable as marker to prove an irradiation treatment.

Vasorelaxant effects of grape polyphenols in rat isolated aorta. Possible involvement of a purinergic pathway.

PubMed

Mendes, Anne; Desgranges, Claude; Chèze, Catherine; Vercauteren, Joseph; Freslon, Jean-Louis

2003-12-01

The purpose of this study was to investigate the mechanism of the vascular relaxation produced by polyphenolic substances from red wine, with a particular focus on the possible involvement of purinoceptors. With this aim, relaxing responses induced by procyanidin from grape seeds (GSP), anthocyanins, catechin and epicatechin were assessed in rat isolated aortic rings left intact (+E) or endothelium-denuded (-E). In preparations precontracted with noradrenaline, incubation with NG-nitro-L-arginine methyl ester (100 microM, 30 min) fully inhibited the GSP-induced relaxations. Concentration-effect curves to these substances (from 10(-7) to 10(-1) g/L) were determined in depolarized (60 mM KCl) preparations in control condition, after incubation with reactive blue 2 (an antagonist of P2Y purinoceptors, 30 microM), with apyrase (an enzyme which hydrolyses ATP and ADP, 0.8 U/mL) or with alpha,beta-methylene ATP (an inhibitor of ecto ATPases, 10 microM). In (+E) rings, relaxations (expressed as percentage of initial contraction) were 41 +/- 2 and 37 +/- 3 for GSP and anthocyanins, respectively. Only modest relaxations (ca. 10%) were observed in (-E) rings, as it was the case for catechin and epicatechin in (+/- E) rings. Reactive blue 2 or apyrase inhibited the GSP- and anthocyanin-induced relaxations in (+E) rings, while alpha,beta-methylene ATP shifted to the left the relaxation curves obtained with GSP. These data confirm that modest relaxations observed with catechin and epicatechin are not endothelium-dependent but that GSP and anthocyanins induce a relaxing effect, which is related to the integrity of the endothelium and the synthesis and release of nitric oxide (NO). Furthermore, the inhibition by apyrase and the increase by ecto-ATPase inhibition of the GSP- and anthocyanin-induced relaxation suggest that these substances could act via an initial release of nucleotides, which in turn could activate P2Y1 and/or P2Y2 purinoceptors of endothelial cells, trigger the synthesis and release of NO and then lead to relaxation.

Erythrocyte membrane transporters during human ageing: modulatory role of tea catechins.

PubMed

Pandey, Kanti Bhooshan; Jha, Rashmi; Rizvi, Syed Ibrahim

2013-02-01

Ageing is associated with many physiological and cellular changes, many of which are due to alterations in the plasma membrane. The functions of membrane transporter proteins are crucial for the maintenance of ionic homeostasis between the extra- and intracellular environments. The aim of the present study was to determine the status of erythrocyte membrane transporters, specifically Ca(2+) -ATPases, Na(+) /K(+) -ATPases and the Na(+) /H(+) exchanger (NHE), during ageing in humans. Furthermore, because tea catechins have been reported to possess strong anti-oxidant potential, the study was extended to evaluate the effect of (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin-3-gallate (EGCG) on these transporters as a function of human age. The study was performed on 97 normal healthy subjects (62 men, 35 women; 16-80 years old). To investigate the effects of tea catechins, subjects were divided into three groups: young (<40 years old; n = 34); middle-aged (40-60 years old; n = 32); and old (>60 years old; n = 31). Erythrocyte ghosts/cell suspension from each group were incubated with ECG, EGCG, EGC and EC (10 μmol/L) for 30 min at 37°C prior to assay. Ageing significantly increased NHE activity and decreased Ca(2+) -ATPase activity. There were no significant changes in Na(+) /K(+) -ATPase activity during the ageing process. (-)-Epigallocatechin-3-gallate, EGC, ECG and EC effectively mitigated the changes in membrane transporter activity in erythrocytes from all age groups; however, the effect was more pronounced in the old age group. We hypothesize that impairment in -bound transporters may be one of the possible mechanisms underlying the pathological events during ageing. A higher intake of catechin-rich food may provide some protection against age-dependent diseases. © 2012 The Authors Clinical and Experimental Pharmacology and Physiology © 2012 Wiley Publishing Asia Pty Ltd.

Relationship between the sensory-determined astringency and the flavanolic composition of red wines.

PubMed

Quijada-Morín, Natalia; Regueiro, Jorge; Simal-Gándara, Jesús; Tomás, Esperanza; Rivas-Gonzalo, Julián C; Escribano-Bailón, M Teresa

2012-12-19

The relationship between the proanthocyanidin profile and the perceived astringency was assessed in 13 commercial Tempranillo red wines. The concentration and compositional information were obtained by liquid chromatography with diode array detection coupled to electrospray ionization mass spectrometry after acid-catalyzed depolymerization of wine proanthocyanidins in the presence of excess phloroglucinol. Statistical analysis of the results showed significant correlations between sensory and chemical determinations. Astringency was more affected by the subunit composition than by the total concentration or the average degree of polymerization of wine proanthocyanidins. Higher proportions of epicatechin (EC) subunits in extension positions and gallocatechin (GC) subunits in terminal positions were shown to increase astringency. On the contrary, the amount of epigallocatechin (EGC) in both extension and terminal positions was negatively correlated with the perceived astringency.

Green-Tea and Epigallocatechin-3-Gallate are Bactericidal against Bacillus anthracis

DTIC Science & Technology

2017-06-13

EGCG, catechins such 245 as epigallocatechin and epicatechin gallate are also antibacterial agents. Moreover, the 246 bactericidal activity of green...Sharma A, Gupta S, Sarethy IP, Dang S, Gabrani R. 2012. Green tea extract: possible mechanism 285 and antibacterial activity on skin pathogens. Food...was shown to be responsible for this activity , against 30 both the attenuated B. anthracis ANR and the virulent, encapsulated strain B. anthracis

Transcriptional analysis of apple fruit proanthocyanidin biosynthesis.

PubMed

Henry-Kirk, Rebecca A; McGhie, Tony K; Andre, Christelle M; Hellens, Roger P; Allan, Andrew C

2012-09-01

Proanthocyanidins (PAs) are products of the flavonoid pathway, which also leads to the production of anthocyanins and flavonols. Many flavonoids have antioxidant properties and may have beneficial effects for human health. PAs are found in the seeds and fruits of many plants. In apple fruit (Malus × domestica Borkh.), the flavonoid biosynthetic pathway is most active in the skin, with the flavan-3-ols, catechin, and epicatechin acting as the initiating units for the synthesis of PA polymers. This study examined the genes involved in the production of PAs in three apple cultivars: two heritage apple cultivars, Hetlina and Devonshire Quarrenden, and a commercial cultivar, Royal Gala. HPLC analysis shows that tree-ripe fruit from Hetlina and Devonshire Quarrenden had a higher phenolic content than Royal Gala. Epicatechin and catechin biosynthesis is under the control of the biosynthetic enzymes anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR1), respectively. Counter-intuitively, real-time quantitative PCR analysis showed that the expression levels of Royal Gala LAR1 and ANR were significantly higher than those of both Devonshire Quarrenden and Hetlina. This suggests that a compensatory feedback mechanism may be active, whereby low concentrations of PAs may induce higher expression of gene transcripts. Further investigation is required into the regulation of these key enzymes in apple.

The proposed biosynthesis of procyanidins by the comparative chemical analysis of five Camellia species using LC-MS

PubMed Central

Zhang, Liang; Tai, Yuling; Wang, Yijun; Meng, Qilu; Yang, Yunqiu; Zhang, Shihua; Yang, Hua; Zhang, Zhengzhu; Li, Daxiang; Wan, Xiaochun

2017-01-01

The genus Camellia (C.) contains many species, including C. sinensis, C. assamica, and C. taliensis, C. gymnogyna and C. tachangensis. The polyphenols of C. sinensis and C. assamica are flavan-3-ols monomers and their dimers and trimmers. However, the biosynthesis of procyanidins in Camellia genus remains unclear. In the present study, a comparative chemical analysis of flavan-3-ols, flavan-3-ols glycoside and procyanidins was conducted by high performance liquid chromatography (HPLC) and liquid chromatography diode array detection coupled with triple-quadrupole mass-spectrometry (LC-DAD-QQQ-MS). The results showed that C. tachangensis had a significant higher contents of (-)-epicatechin (EC) and (-)-epigallocatechin (EGC) compared with C. sinensis (p < 0.001). By contrast, higher levels of galloylated catechins were detected in C. sinensis. LC-DAD-MS/MS indicated that the main secondary metabolites of C. tachangensis were non-galloylated catechins, procyanidin dimers and trimers. Furthermore, (-)-epicatechin glucose (EC-glucose) and (-)-epigallocatechin glucose (EGC-glucose) were also abundant in C. tachangensis. A correlation analysis of EC-glucose and procyanidins dimers was conducted in five Camellia species. The levels of EC-glucose were closely related to the procyanidin dimers content. Thus, it was suggested that EC-glucose might be an important substrate for the biosynthesis of procyanidins. PMID:28383067

Influence of Fermentation with Different Lactic Acid Bacteria and in Vitro Digestion on the Biotransformation of Phenolic Compounds in Fermented Pomegranate Juices.

PubMed

Valero-Cases, Estefanía; Nuncio-Jáuregui, Nallely; Frutos, María José

2017-08-09

This study describes the effect of fermentation and the impact of simulated gastrointestinal digestion (SGD) of four fermented pomegranate juices with different lactic acid bacteria (LAB) on the biotransformation of phenolic compounds. The changes of the antioxidant capacity (AOC) and of LAB growth and survival in different fermented juices were also studied. Two new phenolic derivatives (catechin and α-punicalagin) were identified only in fermented juices. During SGD, the AOC increased together with the phenolic derivatives concentration mainly in the juices fermented with Lactobacillus. These derivatives were formed due to the LAB metabolism of the ellagitannins, epicatechin, and catechin after fermentation and during SGD. The FRAP assay performance might be associated with the degradation and biotransformation of catechin. The fermented pomegranate juices with these LAB increased the bioaccessibility of phenolic compounds, ensuring the survival of LAB after SGD, suggesting a possible prebiotic effect of phenolic compounds on LAB.

Catechins activate muscle stem cells by Myf5 induction and stimulate muscle regeneration.

PubMed

Kim, A Rum; Kim, Kyung Min; Byun, Mi Ran; Hwang, Jun-Ha; Park, Jung Il; Oh, Ho Taek; Kim, Hyo Kyeong; Jeong, Mi Gyeong; Hwang, Eun Sook; Hong, Jeong-Ho

2017-07-22

Muscle weakness is one of the most common symptoms in aged individuals and increases risk of mortality. Thus, maintenance of muscle mass is important for inhibiting aging. In this study, we investigated the effect of catechins, polyphenol compounds in green tea, on muscle regeneration. We found that (-)-epicatechin gallate (ECG) and (-)-epigallocatechin-3-gallate (EGCG) activate satellite cells by induction of Myf5 transcription factors. For satellite cell activation, Akt kinase was significantly induced after ECG treatment and ECG-induced satellite cell activation was blocked in the presence of Akt inhibitor. ECG also promotes myogenic differentiation through the induction of myogenic markers, including Myogenin and Muscle creatine kinase (MCK), in satellite and C2C12 myoblast cells. Finally, EGCG administration to mice significantly increased muscle fiber size for regeneration. Taken together, the results suggest that catechins stimulate muscle stem cell activation and differentiation for muscle regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Survey of antioxidant capacity and phenolic composition of blueberry, blackberry, and strawberry in Nanjing*

PubMed Central

Huang, Wu-yang; Zhang, Hong-cheng; Liu, Wen-xu; Li, Chun-yang

2012-01-01

Berries are a good source of natural antioxidants. In the present study, the total antioxidant capacity and phenolic composition of three berry fruits (blueberry, blackberry, and strawberry) cultivated in Nanjing were investigated. Blueberry, with a Trolox equivalent antioxidant capacity (TEAC) value of 14.98 mmol Trolox/100 g dry weight (DW), exhibited the strongest total antioxidant capacity using both the 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. Blueberry also had the highest total phenolic content (TPC, 9.44 mg gallic acid/g DW), total flavonoid content (TFC, 36.08 mg rutin/g DW), and total anthocyanidin content (TAC, 24.38 mg catechin/g DW). A preliminary analysis using high performance liquid chromatography (HPLC) showed that the blueberry, blackberry, and strawberry samples tested contained a range of phenolic acids (including gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, p-coumaric acid, ferulic acid, ellagic acid, and cinnamic acid) and various types of flavonoids (flavone: luteolin; flavonols: rutin, myricetin, quercetrin, and quercetin; flavanols: gallocatechin, epigallocatechin, catechin, and catechin gallate; anthocyanidins: malvidin-3-galactoside, malvidin-3-glucoside, and cyanidin). In particular, the blueberries had high levels of proanthocyanidins and anthocyanidins, which might be responsible for their strong antioxidant activities. These results indicate a potential market role for berries (especially blueberries) as a functional food ingredient or nutraceutical. PMID:22302422

Extraction of Epigallocatechin Gallate and Epicatechin Gallate from Tea Leaves Using β-Cyclodextrin.

PubMed

Cui, Lu; Liu, Yuxuan; Liu, Ting; Yuan, Yahong; Yue, Tianli; Cai, Rui; Wang, Zhouli

2017-02-01

Use of organic solvents to extract phenolic compounds from plants may result in environmental pollution and cause health problems in persons. Replacing organic extraction solvents by green extracting agents without affecting the extraction yield is one of the most pressing problems to be solved. The aim of this study is to evaluate the capacity of β-cyclodextrin (β-CD) to recover phenolic compounds from tea leaves. The extract obtained using the ethanol/water mixture presented the highest total phenolic content, followed by those obtained using β-CD solution and water. HPLC analysis of the extracts showed that the addition of β-CD to the extracting agent had a selective effect on the extraction of epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). The extraction yield of EGCG and ECG using 15 g/L β-CD were higher than that obtained using water and 50% ethanol. Molecular docking results indicated that the molecules of EGCG and ECG were more inclined to interact with β-CD than epigallocatechin, epicatechin, and gallocatechin. The impact of β-CD concentration, temperature, and time on EGCG and ECG extraction from tea leaves was investigated and the maximum amount of EGCG (118.7 mg/g) and ECG (54.6 mg/g) were achieved when extracted with 25 g/L aqueous β-CD solution at 60 °C for 60 min. The present study indicates that aqueous β-CD can be used as an alternative to organic solvents to recover EGCG and ECG from tea leaves. © 2017 Institute of Food Technologists®.

Effects of gut microbiota and time of treatment on tissue levels of green tea polyphenols in mice.

PubMed

Liu, Anna B; Tao, Siyao; Lee, Mao-Jung; Hu, Qi; Meng, Xiaofeng; Lin, Yong; Yang, Chung S

2018-05-08

The previous studies have shown that tea polyphenols are metabolized by gut microbiota. This study investigated the effect of gut microbiota on the bioavailability, tissue levels, and degradation of tea polyphenols. Mice were treated with antibiotics (ampicillin/sulfamethoxazole/trimethoprim) in drinking water and the control mice received water for 11 days, and they were given an AIN93M diet enriched with 0.32% of Polyphenon E. The levels of catechins and their metabolites (if present) in the serum, liver, urine, and fecal samples were determined by high-performance liquid chromatography. The results showed that treatment with antibiotics significantly increased the levels of the major polyphenol, (-)-epigallocatechin-3-gallate (EGCG), in serum and liver samples. Antibiotics also raised the levels of some catechins in urine and fecal samples but decreased the levels of their metabolites. These results suggest that antibiotics eliminated gut microbes and increased the bioavailabilities of these tea catechins. In a second study, mice were given different concentrations of green tea infusions as the drinking fluid. The plasma levels of EGCG and (-)-epicatechin-3-gallate (ECG) at day 112 were significantly lower than those at day 5. The urine levels of EGCG and ECG increased in the first 4 or 5 days, and then decreased to much lower levels at day 23 and beyond. In contrast, the levels of (-)-epigallocatechin and (-)-epicatechin showed a trend of increase during the 112-day experiment, likely owing to microbial hydrolysis of EGCG and ECG. Both sets of experiments support the idea that the degradation of EGCG and ECG by gut microbiota decreases their bioavailabilities. © 2018 BioFactors, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Carbohydrates, volatile and phenolic compounds composition, and antioxidant activity of calabura (Muntingia calabura L.) fruit.

PubMed

Pereira, Gustavo Araujo; Arruda, Henrique Silvano; de Morais, Damila Rodrigues; Eberlin, Marcos Nogueira; Pastore, Glaucia Maria

2018-06-01

Soluble carbohydrates, volatile and phenolic compounds from calabura fruit as well as its antioxidant activity were assessed. The low amount of fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) and similar amount of glucose and fructose allow us to classify the calabura berry as low-FODMAPs. The terpenes β-Farnesene and dendrolasin identified by SPME-GC-MS were the major volatile components. UHPLC-MS/MS analysis revelled gallic acid (5325 μg/g dw) and cyanidin-3-O-glucoside (171 μg/g dw) as the main phenolic compounds, followed by gentisic acid, gallocatechin, caffeic acid and protocatechuic acid. In addition, gallic acid was found mainly in esterified (2883 μg/g dw) and insoluble-bound (2272 μg/g dw) forms. Free and glycosylated forms showed however the highest antioxidant activity due to occurrence of flavonoids (0.28-27 μg/g dw) in these fractions, such as catechin, gallocatechin, epigallocatechin, naringenin, and quercetin. These findings clearly suggest that calabura is a berry with low energy value and attractive colour and flavour that may contribute to the intake of several bioactive compounds with antioxidant activity. Furthermore, this berry have great potential for use in the food industry and as functional food. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sensory-guided decomposition of roasted cocoa nibs (Theobroma cacao) and structure determination of taste-active polyphenols.

PubMed

Stark, Timo; Bareuther, Sabine; Hofmann, Thomas

2005-06-29

Sequential application of solvent extraction, gel permeation chromatography, and RP-HPLC in combination with taste dilution analyses, followed by LC-MS and 1D/2D-NMR experiments and thiolytic degradation, revealed that, besides theobromine and caffeine, the flavan-3-ols epicatechin, catechin, procyanidin B-2, procyanidin B-5, procyanidin C-1, [epicatechin-(4beta-->8)](3)-epicatechin, and [epicatechin-(4beta-->8)](4)-epicatechin were among the key compounds contributing to the bitter taste as well as the astringent mouthfeel imparted upon consumption of roasted cocoa. In addition, a series of quercetin, naringenin, luteolin, and apigenin glycopyranosides as well as a family of not previously identified amino acid amides, namely, (+)-N-[4'-hydroxy-(E)-cinnamoyl]-L-aspartic acid, (+)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-aspartic acid, (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-glutamic acid, (-)-N-[4'-hydroxy-(E)-cinnamoyl]-L-glutamic acid, (-)-N-[4'-hydroxy-(E)-cinnamoyl]-3-hydroxy-L-tyrosine, (+)-N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-aspartic acid, and (+)-N-(E)-cinnamoyl-L-aspartic acid, have been identified as key astringent compounds of roasted cocoa. Furthermore, (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-3-hydroxy-l-tyrosine (clovamide), (-)-N-[4'-hydroxy-(E)-cinnamoyl]-L-tyrosine (deoxyclovamide), and (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-tyrosine, reported previously as antioxidants, have been found as contributors of cocoa's astringent taste. By means of the half-tongue test, the taste thresholds of flavan-3-ols and glycosides have been determined.

Flavan-3-ols Are an Effective Chemical Defense against Rust Infection1[OPEN

PubMed Central

Unsicker, Sybille B.; Fellenberg, Christin; Schmidt, Axel

2017-01-01

Phenolic secondary metabolites are often thought to protect plants against attack by microbes, but their role in defense against pathogen infection in woody plants has not been investigated comprehensively. We studied the biosynthesis, occurrence, and antifungal activity of flavan-3-ols in black poplar (Populus nigra), which include both monomers, such as catechin, and oligomers, known as proanthocyanidins (PAs). We identified and biochemically characterized three leucoanthocyanidin reductases and two anthocyanidin reductases from P. nigra involved in catalyzing the last steps of flavan-3-ol biosynthesis, leading to the formation of catechin [2,3-trans-(+)-flavan-3-ol] and epicatechin [2,3-cis-(−)-flavan-3-ol], respectively. Poplar trees that were inoculated with the biotrophic rust fungus (Melampsora larici-populina) accumulated higher amounts of catechin and PAs than uninfected trees. The de novo-synthesized catechin and PAs in the rust-infected poplar leaves accumulated significantly at the site of fungal infection in the lower epidermis. In planta concentrations of these compounds strongly inhibited rust spore germination and reduced hyphal growth. Poplar genotypes with constitutively higher levels of catechin and PAs as well as hybrid aspen (Populus tremula × Populus alba) overexpressing the MYB134 transcription factor were more resistant to rust infection. Silencing PnMYB134, on the other hand, decreased flavan-3-ol biosynthesis and increased susceptibility to rust infection. Taken together, our data indicate that catechin and PAs are effective antifungal defenses in poplar against foliar rust infection. PMID:29070515

Flavan-3-ols Are an Effective Chemical Defense against Rust Infection.

PubMed

Ullah, Chhana; Unsicker, Sybille B; Fellenberg, Christin; Constabel, C Peter; Schmidt, Axel; Gershenzon, Jonathan; Hammerbacher, Almuth

2017-12-01

Phenolic secondary metabolites are often thought to protect plants against attack by microbes, but their role in defense against pathogen infection in woody plants has not been investigated comprehensively. We studied the biosynthesis, occurrence, and antifungal activity of flavan-3-ols in black poplar ( Populus nigra ), which include both monomers, such as catechin, and oligomers, known as proanthocyanidins (PAs). We identified and biochemically characterized three leucoanthocyanidin reductases and two anthocyanidin reductases from P. nigra involved in catalyzing the last steps of flavan-3-ol biosynthesis, leading to the formation of catechin [2,3-trans-(+)-flavan-3-ol] and epicatechin [2,3-cis-(-)-flavan-3-ol], respectively. Poplar trees that were inoculated with the biotrophic rust fungus ( Melampsora larici-populina ) accumulated higher amounts of catechin and PAs than uninfected trees. The de novo-synthesized catechin and PAs in the rust-infected poplar leaves accumulated significantly at the site of fungal infection in the lower epidermis. In planta concentrations of these compounds strongly inhibited rust spore germination and reduced hyphal growth. Poplar genotypes with constitutively higher levels of catechin and PAs as well as hybrid aspen ( Populus tremula × Populus alba ) overexpressing the MYB134 transcription factor were more resistant to rust infection. Silencing PnMYB134 , on the other hand, decreased flavan-3-ol biosynthesis and increased susceptibility to rust infection. Taken together, our data indicate that catechin and PAs are effective antifungal defenses in poplar against foliar rust infection. © 2017 American Society of Plant Biologists. All Rights Reserved.

Isolation of proanthocyanidins from red wine, and their inhibitory effects on melanin synthesis in vitro.

PubMed

Fujimaki, Takahiro; Mori, Shoko; Horikawa, Manabu; Fukui, Yuko

2018-05-15

The red wines made from Vitis vinifera were identified as skin-whitening effectors by using in vitro assays. OPCs in the wine were evaluated for tyrosinase activity and melanogenesis. Strong tyrosinase inhibitory activity was observed in fractions with high oligomeric proanthocyanidin (OPC) content. Among OPC dimers, a strong inhibitory effect on tyrosinase was observed with OPCs which contain (+)-catechin as an upper unit. Melanogenesis inhibitory effect was observed with OPCs which have (-)-epicatechin as upper units. Also, OPC trimers, upper and middle units joined with 4 → 8 bonds, showed stronger effects compared to trimers with 4 → 6 linkages. Interestingly, (-)-epicatechin-(4β → 8)-(-)-epicatechin 3-O-gallate, which is a unique component of grapes has potent inhibitory effects on both tyrosinase and melanogenesis. Our data provide structural information about such active compounds. These results suggest that red wines containing OPC, have high melanogenesis inhibitory effect and are supposed to have skin-whitening effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Studies on chemical constituents of Illicium simonsii].

PubMed

Shang, Xiao-Ya; Guo, Miao-Ru; Zhao, Cong-Wei; Li, Shuai

2008-11-01

To study the chemical constituents from the active fractions against HIV in vitro, a crude ethanolic extract of Illicium simonsii. The compounds were isolated with column chromatography methods. MS and NMR spectroscopic methods were used to determine the structures of the compounds. Seven compounds were isolated from the active fractions against HIV in vitro of the 90% ethanol extract and their structures were elucidated as (+)-catechin (1), (-)-epicatechin (2), (+)-catechin 3-O-alpha-L-rhamnopyranoside (3), kaempferol 3-O-alpha-L-rhamnopyranoside (4), quercetin 3-O-alpha-L-rhamnopyranoside (5), erigeside C (6) and daucosterol (7). Seven compounds were isolated from this plant for the first time, but none of them exhibited active against HIV in vitro. Compounds 3 and 6 were isolated from this genus for the first time.

Proanthocyanidins from the bark of Hamamelis virginiana exhibit antimutagenic properties against nitroaromatic compounds.

PubMed

Dauer, A; Metzner, P; Schimmer, O

1998-05-01

The antimutagenic activity of Hamamelis virginiana bark was examined in the Ames assay. A commercial tincture and a methanolic extract showed dose-dependent inhibitory effects on mutagenicity induced by 2-nitrofluorene. Tannin-free samples did not display any inhibition. Bioassay-guided fractionation resulted in the isolation of two active fractions which were shown to contain oligomeric, proanthocyanidins. They were capable of inhibiting the mutagenicity of selected nitroaromatic compounds. The mechanism of antimutagenic action was also studied. The proanthocyanidins did not act as bioantimutagens, but rather as direct-acting desmutagens. The antimutagenic effect increased with an increasing degree of polymerisation in the proanthocyanidins. The most active fraction consisted of catechin and gallocatechin oligomers with an average polymerisation degree of 9.2.

(-)-Epicatechin derivate from Orostachys japonicus as potential inhibitor of the human butyrylcholinesterase.

PubMed

Kim, Jang Hoon; Lee, Sang-Hyun; Lee, Hyun Woo; Sun, Ya Nan; Jang, Won-Hee; Yang, Seo-Young; Jang, Hae-Dong; Kim, Young Ho

2016-10-01

Cholinesterase inhibitors block the bioconversion of neurotransmitters by cholinesterase in the nervous system. Epicatechin derivatives (1, 3 and 5), polyphenols (6 and 7) from Orostachys japonicus, and catechin derivatives (2 and 4) from our in-house library were evaluated for their inhibitory activity on cholinesterase. Compound 5 exhibited IC50 values of 58.3±2.4 and 17.8±3.8μg/mL on AChE and BuChE, respectively. Compound 5 inhibited BuChE more strongly than AChE through a competitive behavior. In silico binding positions of 5 in the active site were predicted using Autodock 4.2 and processed in a 10000-ps molecular dynamics simulation to assess the stability of compound 5 binding. Copyright © 2016 Elsevier B.V. All rights reserved.

The Combination of Catechin and Epicatechin Gallate from Fructus Crataegi Potentiates β-Lactam Antibiotics Against Methicillin-Resistant Staphylococcus aureus (MRSA) in Vitro and in Vivo

PubMed Central

Qin, Rongxin; Xiao, Kangkang; Li, Bin; Jiang, Weiwei; Peng, Wei; Zheng, Jiang; Zhou, Hong

2013-01-01

Fructus crataegi (hawthorn) is the common name of all plant species in the genus Crataegus of the Rosaceae family. In the present study, three monomers of (+)-catechin (C), (−)-epicatechin gallate (ECg) and (−)-epigallocatechin (EGC) were isolated from the hawthorn under the guide of antibacterial sensitization activity. The bioactivity of the composite fraction in enhancing the antibacterial effect of oxacillin against methicillin-resistant Staphylococcus aureus (MRSA) was greater than that of the individual monomer of the hawthorn extract in vitro. Two-fold dilution and checkerboard methods were used to analyze antibacterial activity and screen for the combination and proportion of monomers with the best bioactivity. The result showed that C (128 mg/L) combined with ECg (16 mg/L) had the greatest effect and the combination also reduced the bacterial load in blood of septic mice challenged with a sublethal dose of MRSA, increased daunomycin accumulation within MRSA and down-regulated the mRNA expression of norA, norC and abcA, three important efflux pumps of MRSA. In summary, C and ECg enhanced the antibacterial effect of β-lactam antibiotics against MRSA in vitro and in vivo, which might be related to the increased accumulation of antibiotics within MRSA via suppression of important efflux pumps’ gene expression. PMID:23325048

The combination of catechin and epicatechin callate from Fructus Crataegi potentiates beta-lactam antibiotics against methicillin-resistant staphylococcus aureus (MRSA) in vitro and in vivo.

PubMed

Qin, Rongxin; Xiao, Kangkang; Li, Bin; Jiang, Weiwei; Peng, Wei; Zheng, Jiang; Zhou, Hong

2013-01-16

Fructus crataegi (hawthorn) is the common name of all plant species in the genus Crataegus of the Rosaceae family. In the present study, three monomers of (+)-catechin (C), (-)-epicatechin gallate (ECg) and (-)-epigallocatechin (EGC) were isolated from the hawthorn under the guide of antibacterial sensitization activity. The bioactivity of the composite fraction in enhancing the antibacterial effect of oxacillin against methicillin-resistant Staphylococcus aureus (MRSA) was greater than that of the individual monomer of the hawthorn extract in vitro. Two-fold dilution and checkerboard methods were used to analyze antibacterial activity and screen for the combination and proportion of monomers with the best bioactivity. The result showed that C (128 mg/L) combined with ECg (16 mg/L) had the greatest effect and the combination also reduced the bacterial load in blood of septic mice challenged with a sublethal dose of MRSA, increased daunomycin accumulation within MRSA and down-regulated the mRNA expression of norA, norC and abcA, three important efflux pumps of MRSA. In summary, C and ECg enhanced the antibacterial effect of β-lactam antibiotics against MRSA in vitro and in vivo, which might be related to the increased accumulation of antibiotics within MRSA via suppression of important efflux pumps' gene expression.

Comparison on phenolic compounds and antioxidant properties of cabernet sauvignon and merlot wines from four wine grape-growing regions in China.

PubMed

Jiang, Bao; Zhang, Zhen-Wen

2012-07-25

The antioxidant activities in the Cabernet Sauvignon and Merlot wines from four wine grape-growing regions in China were measured by different analytical assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH·), cupric reducing antioxidant capacity (CUPRAC), superoxide radical-scavenging activity (SRSA) and the contents of total phenols, total flavonoids, total flavanols and total anthocyanins were determined. The results showed that the contents of phenolic compounds and the levels of antioxidant activity in the wine samples greatly varied with cultivar and environmental factors of vine growth. The contents of phenolic compounds and antioxidant activities in Cabernet Sauvignon and Merlot wines from the Yuquanying region of Ningxia were significantly higher than other three regions, followed by the wines from Shacheng region of Hebei, and these parameters were the lowest in Cabernet Sauvignon and Merlot wines from the Changli regions of Hebei and Xiangning region of Shanxi. Taken together, a close relationship between phenolic subclasses and antioxidant activity was observed for the wine samples. Moreover, there were significant discrepancies in the individual phenolic composition and content of four regional Cabernet Sauvignon and Merlot wines, among which the individual phenolic compounds (catechin, epicatechin, cinnamic acid, quercetin-3-O-glucuronide, quercetin-3-O-glucoside, laricitrin-3-O-glucoside and isorhamnetin-3-O-glucoside) revealed a significant correlation (p < 0.05) with the antioxidant capacity in present study, especially for catechin and epicatechin.

Mineral components and anti-oxidant activities of tropical seaweeds

NASA Astrophysics Data System (ADS)

Takeshi, Suzuki; Yumiko, Yoshie-Stark; Joko, Santoso

2005-07-01

Seaweeds are known to hold substances of high nutritional value; they are the richest resources of minerals important to the biochemical reactions in the human body. Seaweeds also hold non-nutrient compounds like dietary fiber and polyphenols. However, there is not enough information on the mineral compounds of tropical seaweeds. Also we are interested in the antioxidant activities of seaweeds, especially those in the tropical area. In this study, Indonesian green, brown and red algae were used as experimental materials with their mineral components analyzed by using an atomic absorption spectrophotometer. The catechins and flavonoids of these seaweeds were extracted with methanol and analyzed by high performance liquid chromatography (HPLC); the antioxidant activities of these seaweeds were evaluated in a fish oil emulsion system. The mineral components of tropical seaweeds are dominated by calcium, potassium and sodium, as well as small amounts of copper, iron and zinc. A green alga usually contains epigallocatechin, gallocatechin, epigallocatechin gallate and catechin. However, catechin and its isomers are not found in some green and red algae. In the presence of a ferrous ion catalyst, all the methanol extracts from the seaweeds show significantly lower peroxide values of the emulsion than the control, and that of a green alga shows the strongest antioxidant activity. The highest chelation on ferrous ions is also found in the extract of this alga, which is significantly different from the other methanol extracts in both 3 and 24 h incubations.

Phenolic compounds from Byrsonima crassifolia L. bark: phytochemical investigation and quantitative analysis by LC-ESI MS/MS.

PubMed

Maldini, Mariateresa; Montoro, Paola; Pizza, Cosimo

2011-08-25

Phytochemical investigation of the methanolic extract of Byrsonima crassifolia's bark led to the isolation of 8 known phenolic compounds 5-O-galloylquinic acid, 3-O-galloylquinic acid, 3,4-di-O-galloylquinic acid, 3,5-di-O-galloylquinic acid, 3,4,5-tri-O-galloylquinic acid, (+)-epicatechin-3-gallate along with (+)-catechin and (+)-epicatechin. Due to their biological value, in the present study, a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, working in multiple reaction monitoring (MRM) mode, has been developed to quantify these compounds. B. crassifolia bark resulted in a rich source of phenolic compounds and particularly of galloyl derivates. The proposed analytical method is promising to be applied to other galloyl derivatives to quantify these bioactive compounds in raw material and final products. Copyright © 2011 Elsevier B.V. All rights reserved.

Isolation and Purification of Condensed Tannin from the Leaves and Branches of Prunus cerasifera and Its Structure and Bioactivities.

PubMed

Song, Wei; Qin, Shao-Tong; Fang, Fei-Xiang; Gao, Zhen-Jiang; Liang, Dan-Dan; Liu, Lu-Lu; Tian, Hong-Tao; Yang, Hai-Bo

2018-06-01

Prunus cerasifera has a rich resource and a weak utilization rate and its biological functions have been investigated. We found that the contents of total phenol (TP) in leaves and branches of Prunus cerasifera were 117.8 ± 8.8 and 100.04 ± 0.9 mg/g, respectively; the contents of soluble condensed tannin (SCT) were 73.95 ± 0.9 and 78.65 ± 4.1 mg/g, respectively; the structure of SCT containing afzelechin/epiafzelechin, catechin/epicatechin, and atechin/epicatechin as the main units and the SCT from leaves and branches exhibited better anti-tyrosinase and antioxidant activities. This study could clarify Prunus cerasifera condensed tannin resource availability and lay a theoretical foundation for its development as a natural antioxidant and tyrosinase inhibitor.

Cocoa-enriched diet enhances antioxidant enzyme activity and modulates lymphocyte composition in thymus from young rats.

PubMed

Ramiro-Puig, Emma; Urpí-Sardà, Mireia; Pérez-Cano, Francisco J; Franch, Angels; Castellote, Cristina; Andrés-Lacueva, Cristina; Izquierdo-Pulido, Maria; Castell, Margarida

2007-08-08

Cocoa is a rich source of flavonoids, mainly (-)-epicatechin, (+)-catechin, and procyanidins. This article reports the effect of continuous cocoa intake on antioxidant capacity in plasma and tissues, including lymphoid organs and liver, from young rats. Weaned Wistar rats received natural cocoa (4% or 10% food intake) for three weeks, corresponding to their infancy. Flavonoid absorption was confirmed through the quantification of epicatechin metabolites in urine. Total antioxidant capacity (TAC) and the activity of antioxidant enzymes, superoxide dismutase (SOD) and catalase, were examined. Cocoa intake enhanced TAC in all tissues especially in thymus. Moreover, thymus SOD and catalase activities were also dose-dependently increased by cocoa. It was also analyzed whether the enhanced antioxidant system in thymus could influence its cellular composition. An increase in the percentage of thymocytes in advanced development stage was found. In summary, cocoa diet enhances thymus antioxidant defenses and influences thymocyte differentiation.

HPLC-UV-ESI-MS analysis of phenolic compounds and antioxidant properties of Hypericum undulatum shoot cultures and wild-growing plants.

PubMed

Rainha, Nuno; Koci, Kamila; Coelho, Ana Varela; Lima, Elisabete; Baptista, José; Fernandes-Ferreira, Manuel

2013-02-01

LC-UV and LC-MS analysis were used to study the phenolic composition of water extracts of Hypericum undulatum (HU) shoot cultures and wild-growing (WG) plants. Total phenolic content (TPC), determined using the Folin-Ciocalteu assay, and the antioxidant activity measured by two complementary methods were also performed for each sample. Mass spectrometry revealed several phenolics acids with quinic acid moieties, flavonols, mostly quercetin, luteolin and apigenin glycosides, flavan-3-ols (catechin and epicatechin) and the xanthonoid mangiferin. Differences in phenolic composition profile and TPC were found between the samples. The major phenolic in HU culture-growing (CG) samples is chlorogenic acid, followed by epicatechin, quercitrin and isoquercitrin. The WG plants presents hyperoside as the main phenolic, followed by isoquercitrin, chlorogenic acid and quercetin. The TPC and antioxidant activity were higher in samples from WG plants. Copyright © 2012 Elsevier Ltd. All rights reserved.

Separation and characterization of polyphenolics from underutilized byproducts of fruit production (Choerospondias axillaris peels): inhibitory activity of proanthocyanidins against glycolysis enzymes.

PubMed

Li, Qian; Chen, Jun; Li, Ti; Liu, Chengmei; Zhai, Yuxin; McClements, David Julian; Liu, Jiyan

2015-12-01

Bioactive proanthocyanidins were isolated from the peel of Choerospondias axillaris fruit, which is a waste product of the food processing industry. Compositional analysis indicated that the proanthocyanidins had extension units mainly consisting of epicatechin gallate or epicatechin, and terminal units mainly consisting of catechin. Numerous polymeric forms of the molecules were detected, including monomers, dimers, and trimers. Certain fractions exhibited strong α-amylase or α-glucosidase inhibition in a dose-dependent manner. Furthermore, their inhibitory activities depended on their degree of polymerization and galloylation. For example, the most bioactive fraction had α-amylase and α-glucosidase inhibitory activities (IC50 values) of 541 and 3.1 μg mL(-1), respectively. This study demonstrates that proanthocyanidins from C. axillaris peels can inhibit carbohydrate digestive enzymes in vitro and may therefore serve as antidiabetic ingredients in functional or medical foods.

Antioxidant compounds and activities of the stem, flower, and leaf extracts of the anti-smoking Thai medicinal plant: Vernonia cinerea Less

PubMed Central

Ketsuwan, Nitinet; Leelarungrayub, Jirakrit; Kothan, Suchart; Singhatong, Supawatchara

2017-01-01

Vernonia cinerea (VC) Less has been proposed as a medicinal plant with interesting activities, such as an aid for smoking cessation worldwide. Despite its previous clinical success in smoking cessation by exhibiting reduced oxidative stress, it has not been approved. The aim of this study was to investigate various antioxidant activity and active compounds that have not been approved, including the protective activity in human red blood cells (RBCs), from the stem, flower, and leaf extracts of VC Less in vitro. These extracts were tested for their antioxidant activity in scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and analyzed by high-performance liquid chromatography (HPLC) for their active compounds: total tannin, five catechin (C) compounds (epicatechin gallate [ECG], C, epicatechin [EC], epigallocatechin gallate [EGCG], and (−)-epigallocatechin [EGC]), flavonoid, nitrite, nitrate, caffeine, and nicotine. Moreover, antioxidant activities of the extracts were evaluated in 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-treated RBCs. The results showed that the flower and leaf of VC Less had higher activity than the stem in scavenging DPPH radicals. The tannin content in the flower and leaf was higher than that in the stem. The leaf had the highest content of the five catechins (C, EC, EGCG, ECG, and EGC), the same as in the flavonoid, when compared to the stem and flower. Furthermore, the leaf extract had higher nitrate and nitrite than the stem. Nicotine content was found to be higher in the leaf when compared to the flower. In addition, the leaf showed protective activity in glutathione (GSH), malondialdehyde (MDA), and protein carbonyl, with a dose response in AAPH-oxidized RBCs, the same as in standard EGCG. Thus, this study concluded that radical scavenging and antioxidant compounds such as catechins, flavonoid, nitrate and nitrite, and nicotine are present in different VC Less parts and are included in the AAPH-oxidized RBC model. PMID:28243061

Antioxidant compounds and activities of the stem, flower, and leaf extracts of the anti-smoking Thai medicinal plant: Vernonia cinerea Less.

PubMed

Ketsuwan, Nitinet; Leelarungrayub, Jirakrit; Kothan, Suchart; Singhatong, Supawatchara

2017-01-01

Vernonia cinerea (VC) Less has been proposed as a medicinal plant with interesting activities, such as an aid for smoking cessation worldwide. Despite its previous clinical success in smoking cessation by exhibiting reduced oxidative stress, it has not been approved. The aim of this study was to investigate various antioxidant activity and active compounds that have not been approved, including the protective activity in human red blood cells (RBCs), from the stem, flower, and leaf extracts of VC Less in vitro. These extracts were tested for their antioxidant activity in scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and analyzed by high-performance liquid chromatography (HPLC) for their active compounds: total tannin, five catechin (C) compounds (epicatechin gallate [ECG], C, epicatechin [EC], epigallocatechin gallate [EGCG], and (-)-epigallocatechin [EGC]), flavonoid, nitrite, nitrate, caffeine, and nicotine. Moreover, antioxidant activities of the extracts were evaluated in 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-treated RBCs. The results showed that the flower and leaf of VC Less had higher activity than the stem in scavenging DPPH radicals. The tannin content in the flower and leaf was higher than that in the stem. The leaf had the highest content of the five catechins (C, EC, EGCG, ECG, and EGC), the same as in the flavonoid, when compared to the stem and flower. Furthermore, the leaf extract had higher nitrate and nitrite than the stem. Nicotine content was found to be higher in the leaf when compared to the flower. In addition, the leaf showed protective activity in glutathione (GSH), malondialdehyde (MDA), and protein carbonyl, with a dose response in AAPH-oxidized RBCs, the same as in standard EGCG. Thus, this study concluded that radical scavenging and antioxidant compounds such as catechins, flavonoid, nitrate and nitrite, and nicotine are present in different VC Less parts and are included in the AAPH-oxidized RBC model.

Transformation of proanthocyanidin A2 to its isomers under different physiological pH conditions and common cell culture medium.

PubMed

Lu, Wen-Chien; Huang, Wei-Ting; Kumaran, Alaganandam; Ho, Chi-Tang; Hwang, Lucy Sun

2011-06-08

Proanthocyanidins constitute an important class of polyphenols ubiquitously found in plants. They have been extensively studied for their antioxidant capacity and bioactivity in vitro and in animal models. However, their stability under different pH conditions and in cell culture medium has not been well documented. In the present study, it was observed that proanthocyanidin A2 (PA2) was relatively more stable in acidic condition than in weak alkaline condition. PA2 was also quite unstable in basal-Dulbecco's Modified Eagle medium (b-DMEM medium) at 37 °C. The addition of PA2 to the cell culture medium accelerated its epimerization with a half-life of <15 min, and ethylenediaminetetraacetic acid (EDTA) could not stop the reaction. The results also demonstrated that the major isomers transformed in the weak alkaline condition or cell culture medium at 37 °C were identified as epicatechin-(4β→8; 2β→O→7)-ent-catechin (proanthocyanidin A4) and epicatechin-(4β→6; 2β→O→7)-ent-catechin. The rates of transformation were dependent on the pH or the components of the medium. Therefore, the results obtained for PA2 in the cell culture bioassays, which were usually carried out for 24 h, might not represent the true activity of the original PA2. The stability and transformation of PA2 should be considered when the bioactivity of PA2 is evaluated in a given cell culture system.

Transcriptional analysis of apple fruit proanthocyanidin biosynthesis

PubMed Central

Henry-Kirk, Rebecca A.

2012-01-01

Proanthocyanidins (PAs) are products of the flavonoid pathway, which also leads to the production of anthocyanins and flavonols. Many flavonoids have antioxidant properties and may have beneficial effects for human health. PAs are found in the seeds and fruits of many plants. In apple fruit (Malus × domestica Borkh.), the flavonoid biosynthetic pathway is most active in the skin, with the flavan-3-ols, catechin, and epicatechin acting as the initiating units for the synthesis of PA polymers. This study examined the genes involved in the production of PAs in three apple cultivars: two heritage apple cultivars, Hetlina and Devonshire Quarrenden, and a commercial cultivar, Royal Gala. HPLC analysis shows that tree-ripe fruit from Hetlina and Devonshire Quarrenden had a higher phenolic content than Royal Gala. Epicatechin and catechin biosynthesis is under the control of the biosynthetic enzymes anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR1), respectively. Counter-intuitively, real-time quantitative PCR analysis showed that the expression levels of Royal Gala LAR1 and ANR were significantly higher than those of both Devonshire Quarrenden and Hetlina. This suggests that a compensatory feedback mechanism may be active, whereby low concentrations of PAs may induce higher expression of gene transcripts. Further investigation is required into the regulation of these key enzymes in apple. Abbreviations:ANOVAanalysis of varianceANRanthocyanidin reductaseDADdiode array detectorDAFBdays after full bloomDFRdihydroflavonol reductaseLARleucoanthocyanidin reductaseLC-MSliquid chromatography/mass spectrometryPAproanthocyanidinqPCRreal-time quantitative PCR PMID:22859681

Dietary flavanols and procyanidin oligomers from cocoa (Theobroma cacao) inhibit platelet function.

PubMed

Murphy, Karen J; Chronopoulos, Andriana K; Singh, Indu; Francis, Maureen A; Moriarty, Helen; Pike, Marilyn J; Turner, Alan H; Mann, Neil J; Sinclair, Andrew J

2003-06-01

Flavonoids may be partly responsible for some health benefits, including antiinflammatory action and a decreased tendency for the blood to clot. An acute dose of flavanols and oligomeric procyanidins from cocoa powder inhibits platelet activation and function over 6 h in humans. This study sought to evaluate whether 28 d of supplementation with cocoa flavanols and related procyanidin oligomers would modulate human platelet reactivity and primary hemostasis and reduce oxidative markers in vivo. Thirty-two healthy subjects were assigned to consume active (234 mg cocoa flavanols and procyanidins/d) or placebo (< or = 6 mg cocoa flavanols and procyanidins/d) tablets in a blinded parallel-designed study. Platelet function was determined by measuring platelet aggregation, ATP release, and expression of activation-dependent platelet antigens by using flow cytometry. Plasma was analyzed for oxidation markers and antioxidant status. Plasma concentrations of epicatechin and catechin in the active group increased by 81% and 28%, respectively, during the intervention period. The active group had significantly lower P selectin expression and significantly lower ADP-induced aggregation and collagen-induced aggregation than did the placebo group. Plasma ascorbic acid concentrations were significantly higher in the active than in the placebo group (P < 0.05), whereas plasma oxidation markers and antioxidant status did not change in either group. Cocoa flavanol and procyanidin supplementation for 28 d significantly increased plasma epicatechin and catechin concentrations and significantly decreased platelet function. These data support the results of acute studies that used higher doses of cocoa flavanols and procyanidins.

Comparative study of neuropharmacological, analgesic properties and phenolic profile of Ajwah, Safawy and Sukkari cultivars of date palm (Phoenix dactylifera).

PubMed

Sheikh, Bassem Yousef; Zihad, S M Neamul Kabir; Sifat, Nazifa; Uddin, Shaikh J; Shilpi, Jamil A; Hamdi, Omer A A; Hossain, Hemayet; Rouf, Razina; Jahan, Ismet Ara

2016-01-01

In addition to the rich nutritional value, date palm is also used in various ethnobotanical practices for the treatment of various disease conditions. Present investigation was undertaken to examine the neuropharmacological and antinociceptive effect of the ethanol extract of three date cultivars growing in Saudi Arabia, namely Ajwah, Safawy and Sukkari. Neuropharmacological effect was observed by pentobarbitone induced sleeping time, open field, and hole board test. Antinociceptive activity was tested by acetic acid induced writhing and hot plate test. The date extracts were also subjected to HPLC analysis to detect the presence of common bioactive polyphenols. All the three date extracts extended the pentobarbitone induced sleeping time, reduced locomotor activity in open field test and reduced exploratory behaviour in hole board test in mice. The extracts also reduced acetic acid induced writhing and delayed response time in hot plate test. The activities were stronger for Ajwah than the other two date cultivars. HPLC analysis indicated the presence of trans -ferulic acid in all three cultivars, while (+)-catechin and (-)-epicatechin only in Ajwah and Safawy. The observed neuropharmacological and analgesic activity could be partly due to the presence of (+)-catechin, (-)-epicatechin and trans -ferulic acid, three important plant polyphenols well known for their neuroprotective activity and their ability to exert antioxidant activity on brain cells. Present investigation also supports the ethnobotanical use of date palm to provide ameliorating effects in pain and CNS disorders.

Assessment of the polyphenolic composition of the organic extracts of Mauritian black teas: a potential contributor to their antioxidant functions.

PubMed

Luximon-Ramma, Amitabye; Neergheen, Vidushi S; Bahorun, Theeshan; Crozier, Alan; Zbarsky, Virginia; Datla, Krishna P; Dexter, David T; Aruoma, Okezie I

2006-01-01

There is increasing interest in the emerging view that tea improves the antioxidant status in vivo and thereby helps to lower risk of certain types of cancer, coronary heart disease and stroke and its component biofactors could provide prophylactic potential for these diseases. The polyphenolic composition and the antioxidant properties of organic extracts (acetone/methanol) of Mauritian commercial black teas were evaluated. HPLC data of the individual compounds revealed remarkably high levels (+)-Catechin ((+)-C), (-)-epicatechin ((-)-EC), (-)-epicatechin 3-gallate ((-)-ECG), (-)-epigallocatechin ((-)-EGC), (-)-epigallocatechin 3-gallate ((-)-EGCG) and gallic acid. Analysis of hydrolysed extracts indicated that quercetin was the dominant flavonol aglycone with traces of myricetin and kaempferol. Based on the Ferric Reducing Antioxidant Power (FRAP) and the Trolox Equivalent Antioxidant Capacity (TEAC) assays Extra tea from Bois Chéri exhibited the highest antioxidant potential. Linear regression analyses showed that the antioxidant capacities of the organic extracts are strongly influenced by total phenols (TEAC: r=0.95 and FRAP: r=0.96) and to a lesser extent by total proanthocyanidin and total flavonoid contents. Catechins and gallic acid seem to add up to the overall antioxidant capacity of black tea extracts. The fresh tea leaves had high levels of total phenols, total flavonoids, total proanthocyanidin and exhibited greater antioxidant potential when compared with black teas. Organic extracts of endemic teas represent useful source of phenolic antioxidants supplements for prophylactic use.

Rate of antioxidant degradation and color variations in dehydrated apples as related to water activity.

PubMed

Lavelli, Vera; Vantaggi, Claudia

2009-06-10

Dehydrated apples were studied to evaluate the effects of water activity on the stability of their antioxidants and color. Apples were freeze-dried, ground, then equilibrated, and stored at eight water activity levels, ranging from 0.058 to 0.747, at 40 degrees C. Their contents of hydroxycinnamic acids, dihydrochalcones, catechin, epicatechin, polymeric flavan-3-ols, and hydroxymethylfurfural, their antioxidant activity values, and their Hunter colorimetric parameters were analyzed at different storage times. Antioxidant degradation followed pseudo-first-order kinetics and was accelerated by increasing the water activity. The order of antioxidant stability in the products at water activity levels below 0.316 was catechin, epicatechin, and ascorbic acid < total procyanidins < dihydrochalcones and p-coumaric acid < chlorogenic acid; however, in the products at water activity levels above 0.316, the degradation of all antioxidants was very fast. The hydroxymethylfurfural formation rate increased exponentially during storage, especially at high water activity levels. The antioxidant activity of the dehydrated apples decreased during storage, consistent with antioxidant loss. The variations of the colorimetric parameters, namely, lightness (L*), redness (a*), and yellowness (b*), followed pseudo-zero-order kinetics and were accelerated by increasing water activity. All analytical indices indicated that the dehydrated apples were stable at water activity levels below 0.316, with the degradation rate accelerating upon exposure to higher relative humidities. Above 0.316, a small increase in water activity of the product would sharply increase the degradation rate constants for both antioxidant and color variations.

Antioxidant and Cytoprotective Effects of Tibetan Tea and Its Phenolic Components.

PubMed

Xie, Hong; Li, Xican; Ren, Zhenxing; Qiu, Weimin; Chen, Jianlan; Jiang, Qian; Chen, Ban; Chen, Dongfeng

2018-01-24

Tibetan tea (Kangzhuan) is an essential beverage of the Tibetan people. In this study, a lyophilized aqueous extract of Tibetan tea ( LATT ) was prepared and analyzed by HPLC. The results suggested that there were at least five phenolic components, including gallic acid, and four catechins (i.e., (+)-catechin, (-)-catechin gallate ( CG ), (-)-epicatechin gallate ( ECG ), and (-)-epigallocatechin gallate). Gallic acid, the four catechins, and LATT were then comparatively investigated by four antioxidant assays: ferric reducing antioxidant power, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•) scavenging, 1,1-diphenyl-2-picryl-hydrazl radical scavenging, and 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) radical scavenging assays. In these assays, LATT, along with the five phenolic components, increased their antioxidant effects in a concentration-dependent manner; however, the half maximal scavenging concentrations of ECG were always lower than those of CG . Gallic acid and the four catechins were also suggested to chelate Fe 2+ based on UV-visible spectral analysis. Ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) analysis suggested that, when mixed with PTIO•, the five phenolic components could yield two types of radical adduct formation (RAF) products (i.e., tea phenolic dimers and tea phenolic-PTIO• adducts). In a flow cytometry assay, (+)-catechin and LATT was observed to have a cytoprotective effect towards oxidative-stressed bone marrow-derived mesenchymal stem cells. Based on this evidence, we concluded that LATT possesses antioxidative or cytoprotective properties. These effects may mainly be attributed to the presence of phenolic components, including gallic acid and the four catechins. These phenolic components may undergo electron transfer, H⁺-transfer, and Fe 2+ -chelating pathways to exhibit antioxidative or cytoprotective effects. In these effects, two diastereoisomeric CG and ECG showed differences to which a steric effect from the 2-carbon may contribute. Phenolic component decay may cause RAF in the antioxidant process.

Estrogen and the Dietary Phytoestrogen Resveratrol as Regulators of the Rho GTPase Rac in Breast Cancer Research

DTIC Science & Technology

2009-06-01

toxicity of a red grape wine flavonoid fraction against MCF 7 cells. Breast Cancer Res Treat 85:65 79. doi:10.1023/B: BREA.0000021048.52430.c0 10...Major flavonoids in grape seeds and skins: antioxidant capacity of catechin, epicatechin, and gallic acid. J Agric Food Chem 52:255 260. doi:10.1021...The effect of the flavonoid diosmin, grape seed extract and red wine on the pul monary metastatic B16F10 melanoma. Histol Histopathol 20:1121 1129 Clin

Evaluation of Antioxidant and Free Radical Scavenging Capacities of Polyphenolics from Pods of Caesalpinia pulcherrima

PubMed Central

Hsu, Feng-Lin; Huang, Wei-Jan; Wu, Tzu-Hua; Lee, Mei-Hsien; Chen, Lih-Chi; Lu, Hsiao-Jen; Hou, Wen-Chi; Lin, Mei-Hsiang

2012-01-01

Thirteen polyphenolics were isolated from fresh pods of Caesalpinia pulcherrima using various methods of column chromatography. The structures of these polyphenolics were elucidated as gallic acid (1), methyl gallate (2), 6-O-galloyl-d-glucoside (3), methyl 6-O-galloyl-β-d-glucoside (4), methyl 3,6-di-O-galloyl-α-d-glucopyranoside (5), gentisic acid 5-O-α-d-(6′-O-galloyl)glucopyranoside (6), guaiacylglycerol 4-O-β-d-(6′-O-galloyl)glucopyranoside (7), 3-methoxy-4-hydroxyphenol 1-O-β-d-(6′-O-galloyl) glucopyranoside (8), (+)-gallocatechin (9), (+)-catechin (10), (+)-gallocatechin 3-O-gallate (11), myricetin 3-rhamnoside (12), and ampelopsin (13). All isolated compounds were tested for their antioxidant activities in the 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and peroxynitrite radicals scavenging assays. Among those compounds, 11, 12, and 2 exhibited the best DPPH-, hydroxyl-, and peroxynitrite radical-scavenging activities, respectively. Compound 7 is a new compound, and possesses better scavenging activities towards DPPH but has equivalent hydroxyl radical scavenging activity when compared to BHT. The paper is the first report on free radical scavenging properties of components of the fresh pods of Caesalpinia pulcherrima. The results obtained from the current study indicate that the free radical scavenging property of fresh pods of Caesalpinia pulcherrima may be one of the mechanisms by which this herbal medicine is effective in several free radical mediated diseases. PMID:22754350

Procyanidins protect Fao cells against hydrogen peroxide-induced oxidative stress.

PubMed

Roig, Roser; Cascón, Esther; Arola, Lluis; Bladé, Cinta; Salvadó, M Josepa

2002-08-15

In this paper, we evaluate the extent to which flavonoids in red wine (catechin, epicatechin, quercetin and procyanidins) protect against hydrogen peroxide-induced oxidative stress in Fao cells. When cells were exposed to H(2)O(2), malondialdehyde (MDA) levels, oxidized glutathione (GSSG) levels and lactate dehydrogenase (LDH) release increased, indicating membrane damage and oxidative stress. All the flavonoids studied, and in particular epicatechin and quercetin, protected the plasma membrane. Only procyanidins lowered MDA levels and LDH leakage, maintained a higher reduced/oxidized glutathione ratio, and increased catalase/superoxide dismutase and glutathione peroxidase/superoxide dismutase ratios, and glutathione reductase and glutathione transferase activities. These results show that the procyanidin mixture has a greater antioxidant effect than the individual flavonoids studied, probably due to its oligomer content and/or the additive/synergistic effect of its compounds. This suggests that the mixture of flavonoids found in wine has a greater effect than individual phenols, which may explain many of the healthy effects attributed to wine.

A new class of anthocyanin-procyanidin condensation products detected in red wine by electrospray ionization multi-stage mass spectrometry analysis.

PubMed

Sun, Baoshan; Fernandes, Tiago A; Spranger, M Isabel

2010-02-01

In our previous work, we have identified, in a model wine solution containing malvidin 3-glucoside, epicatechin and acetaldehyde, a new condensation product--hydroxylethyl-malvidin-3-glucoside-ethyl-epicatechin. The objective of this work was to verify the presence of such new condensation products in red wine. For this purpose, red wine was fractionated into various fractions by column chromatography on LiChroprep RP 18 and on Toyopearl 40 (F). The phenolic composition of each fraction was verified by HPLC-DAD and direct-infusion ESI-MS(n) analysis. In addition to the well-known anthocyanins and their acetyl and coumaroyl derivatives, and several direct and indirect anthocyanin-(epi)catechin condensation products, a new class of pigmented products, namely hydroxyethyl-anthocyanin-ethyl-flavanol compounds, have been detected in red wine. The new class of pigmented products would be expected to be the major pigments responsible for the color of aged red wine. Copyright 2010 John Wiley & Sons, Ltd.

Phytochemical Constituents, Health Benefits, and Industrial Applications of Grape Seeds: A Mini-Review

PubMed Central

Zhang, Hongxia

2017-01-01

Grapes are one of the most widely grown fruits and have been used for winemaking since the ancient Greek and Roman civilizations. Grape seeds are rich in proanthocyanidins which have been shown to possess potent free radical scavenging activity. Grape seeds are a complex matrix containing 40% fiber, 16% oil, 11% proteins, and 7% complex phenols such as tannins. Grape seeds are rich sources of flavonoids and contain monomers, dimers, trimers, oligomers, and polymers. The monomeric compounds includes (+)-catechins, (−)-epicatechin, and (−)-epicatechin-3-O-gallate. Studies have reported that grape seeds exhibit a broad spectrum of pharmacological properties against oxidative stress. Their potential health benefits include protection against oxidative damage, and anti-diabetic, anti-cholesterol, and anti-platelet functions. Recognition of such health benefits of proanthocyanidins has led to the use of grape seeds as a dietary supplement by the consumers. This paper summarizes the studies of the phytochemical compounds, pharmacological properties, and industrial applications of grape seeds. PMID:28914789

Profile of plasma and urine metabolites after the intake of almond [Prunus dulcis (Mill.) D.A. Webb] polyphenols in humans.

PubMed

Urpi-Sarda, Mireia; Garrido, Ignacio; Monagas, María; Gómez-Cordovés, Carmen; Medina-Remón, Alexander; Andres-Lacueva, Cristina; Bartolomé, Begoña

2009-11-11

Nut skins are considered to be a rich source of polyphenols and may be partially responsible for the numerous health effects associated with nut consumption. However, more bioavailability studies of nut skin polyphenols are needed to understand the health effects derived from nut consumption. The aim of the present study was to determine the profiles of both phase II and microbial-derived phenolic metabolites in plasma and urine samples before and after the intake of almond skin polyphenols by healthy human subjects (n = 2). Glucuronide, O-methyl glucuronide, sulfate, and O-methyl sulfate derivatives of (epi)catechin, as well as the glucuronide conjugates of naringenin and glucuronide and sulfate conjugates of isorhamnetin, were detected in plasma and urine samples after consumption of almond skin polyphenols. The main microbial-derived metabolites of flavanols, such as 5-(dihydroxyphenyl)-gamma-valerolactone and 5-(hydroxymethoxyphenyl)-gamma-valerolactone, were also detected in their glucuronide and sulfate forms. In addition, numerous metabolites derived from further microbial degradation of hydroxyphenylvalerolactones, including hydroxyphenylpropionic, hydroxyphenylacetic, hydroxycinnamic, hydroxybenzoic, and hydroxyhippuric acids, registered major changes in urine after the consumption of almond skin polyphenols. The urinary excretion of these microbial metabolites was estimated to account for a larger proportion of the total polyphenol ingested than phase II metabolites of (epi)catechin, indicating the important role of intestinal bacteria in the metabolism of highly polymerized almond skin polyphenols. To the authors' knowledge this study constitutes the most complete report of the absorption of almond skin polyphenols in humans.

Interaction between Ester-Type Tea Catechins and Neutrophil Gelatinase-Associated Lipocalin: Inhibitory Mechanism.

PubMed

Zhang, Wei; Li, Xiao; Hua, Fang; Chen, Wei; Wang, Wei; Chu, Gang-Xiu; Bao, Guan-Hu

2018-02-07

Tea is thought to alleviate neurotoxicity due to the antioxidative effect of ester-type tea catechins (ETC). Neutrophil gelatinase-associated lipocalin (NGAL) can sensitize β-amyloid (Aβ) induced neurotoxicity, and inhibitors of NGAL may relieve associated symptoms. As such, the interactions of ETC with NGAL were investigated by fluorescence spectrometry and molecular simulation. NGAL fluorescence is quenched regularly when being added with six processing types of tea infusion (SPTT) and ETC. Thermodynamic analyses suggest that ETC with more catechol moieties has a stronger binding capacity with NGAL especially in the presence of Fe 3+ . (-)-Epicatechin 3-O-caffeoate (ECC), a natural product isolated from Zijuan green tea, shows the strongest binding ability with NGAL (K d = 15.21 ± 8.68 nM in the presence of Fe 3+ ). All ETC are effective in protecting nerve cells against H 2 O 2 or Aβ 1-42 induced injury. The inhibitory mechanism of ETC against NGAL supports its potential use in attenuation of neurotoxicity.

Antiprotozoal, Antibacterial and Antidiarrheal Properties from the Flowers of Chiranthodendron pentadactylon and Isolated Flavonoids.

PubMed

Calzada, Fernando; Juárez, Teresa; García-Hernández, Normand; Valdes, Miguel; Ávila, Oscar; Mulia, Lilian Yepez; Velázquez, Claudia

2017-01-01

Chiranthodendron pentadactylon Larreat. (Sterculiaceae) is a Mexican plant used in traditional medicine for the treatment of heart disease symptoms and infectious diarrhea. To evaluate in vitro antiprotozoal and antibacterial activities and in vivo antidiarrheal activity from the flowers of C. pentadactylon using the extract, fractions, and major isolated flavonoids. Bioassay-guided fractionation of the methanol extract of C. pentadactylon (MECP) led to the isolation of five flavonoids, tiliroside, astragalin, isoquercitrin, (+)-catechin, and (-)-epicatechin. Antimicrobial activities were tested on two protozoa ( Entamoeba histolytica and Giardia lamblia ) and nine bacterial enteropathogens (two Escherichia coli strains, two Shigella sonnei strains, two Shigella flexneri strains, two Salmonella sp. strains, and Vibrio cholerae ) isolated from feces of children with acute diarrhea or dysentery and resistant to chloramphenicol. Also, antidiarrheal activity was tested on cholera toxin-induced diarrhea in male Balb-c mice. Epicatechin was the most potent antiamoebic and antigiardial compound with IC 50 values of 1.9 μg/mL for E. histolytica and 1.6 μg/mL for G. lamblia ; tiliroside showed moderate antiprotozoal activity against both protozoan. In contrast, in the antibacterial activity, tiliroside was the most potent compound on all microorganisms with minimum inhibitory concentration values less than 0.7 mg/mL. In the case of cholera toxin-induced diarrhea, epicatechin was the most potent flavonoid with IC 50 of 14.7 mg/kg. Epicatechin and tiliroside were the flavonoids responsible for antimicrobial andantidiarrheal activities of C. pentadactylon . Its antiprotozoal, antibacterial, and antidiarrheal properties are in good agreement with the traditional medicinal use of C. pentadactylon for the treatment of infectious diarrhea. Epicatechin was the most potent antiamoebic and antigiardial compound with IC 50 values of 1.9 μg/mL for E. histolytica and 1.6 μg/mL for G. lamblia .Tiliroside showed antibacterial activity against all microorganisms tested with MIC values less than 0.7 mg/mL.Epicatechin was the most potent flavonoid on cholera toxin-induced diarrhea with IC 50 of 14.7 mg/kg. Abbreviations used: MECP: Methanol extract of C. pentadactylon .

Evaluation of thrombin inhibitory activity of catechins by online capillary electrophoresis-based immobilized enzyme microreactor and molecular docking.

PubMed

Li, Qiao-Qiao; Yang, Feng-Qing; Wang, Yin-Zhen; Wu, Zhao-Yu; Xia, Zhi-Ning; Chen, Hua

2018-08-01

An online capillary electrophoresis (CE)-based thrombin (THR) immobilized enzyme microreactor (IMER) method was established to screen THR inhibitors in this study. S-2366 was used as chromogenic substrate for determination of THR activity and other kinetic constants. After continuously run for 50 times, the prepared IMER could still remain 89% of the initial immobilized enzyme activity. The Michaelis-Menten constant (K m ) of immobilized THR was measured as 0.514 mmol/L and the half-maximal inhibitory concentration (IC 50 ) and inhibition constant (K i ) of argatroban on THR were determined as 78.07 and 26.53 nmol/L, respectively, which indicated that CE-based THR IMER was successfully established and could be applied to screen THR inhibitors. Then the prepared IMER was used to investigate the inhibitory potency on THR of four main catechins in green tea including epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG). The results showed that ECG and EGCG had good THR inhibition activity and their inhibition rates at concentration of 200 μmol/L were 53.2 ± 3.8% and 55.8 ± 2.6%, respectively, which was in consistent with the results of microplate reader assay. Additionally, molecular docking results showed that the benzopyran groups of ECG and EGCG were inserted into the THR active pocket and interacted with residues LYS60F, TRP60D, TRY60A, IEU99, GLY216, HIS57 and SER195, but EC and EGC did not. Therefore, the developed CE-based THR IMER is reliable method for measuring THR inhibitory activity of natural inhibitors. Copyright © 2018 Elsevier B.V. All rights reserved.

A randomized, placebo-controlled, double-blind study on the effects of (-)-epicatechin on the triglyceride/HDLc ratio and cardiometabolic profile of subjects with hypertriglyceridemia: Unique in vitro effects.

PubMed

Gutiérrez-Salmeán, Gabriela; Meaney, Eduardo; Lanaspa, Miguel A; Cicerchi, Christina; Johnson, Richard J; Dugar, Sundeep; Taub, Pam; Ramírez-Sánchez, Israel; Villarreal, Francisco; Schreiner, George; Ceballos, Guillermo

2016-11-15

Cardiometabolic disruptions such as insulin resistance, obesity, high blood pressure, hyperglycemia, and dyslipidemias, are known to increase the risk for cardiovascular and metabolic diseases such as type 2 diabetes mellitus and atherosclerosis. Several screening tools for assessing cardiometabolic risk have been developed including the TG/HDLc ratio, which has been, demonstrated to possess a strong association with insulin resistance and coronary disease. Dietary modifications, together with regular moderate exercise have proven to be effective in attenuating cardiometabolic disruptions. However, they often exhibit poor long-term patient compliance. Nutraceutics, including (-)-epicatechin (EPI), have gained increasing interest as coadjuvant effective and safe therapies that are able to attenuate hypertension, hyperglycemia, hyperinsulinemia, hypertriglyceridemia and hypoalphalipoproteinemia. The aims of this study were: 1) to compare the in vitro effect of EPI vs. (+)-catechin on fructose induced triglyceride accumulation and mitochondrial function in Hep2 cells in culture, 2) to evaluate the efficacy of EPI treatment in reducing fasting blood triglycerides and improving the TG/HDLc ratio in hypertriglyceridemic patients with a total daily dose of 100mg of EPI. Secondary clinical variables included total cholesterol, LDLc, fructosamine, glucose, insulin, and high sensitivity C-reactive protein blood levels. Our results provide preliminary evidence as to favorable effects of EPI on glycemia homeostasis, lipid profile and systemic inflammation such bioactive actions are not class-effects (i.e. limited to their antioxidant potential) but instead, may result from the specific activation of associated downstream signaling pathways since catechin has no effects. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Determination of flavonoids and phenolics and their distribution in almonds.

PubMed

Milbury, Paul E; Chen, Chung-Yen; Dolnikowski, Gregory G; Blumberg, Jeffrey B

2006-07-12

Limited information is available concerning the qualitative and quantitative composition of polyphenolic compounds, especially flavonoids, in almonds. We determined total phenols, flavonoids, and phenolic acids in California almond (Prunus dulcis) skins and kernels among the principal almond varieties (Butte, Carmel, Fritz, Mission, Monterey, Nonpareil, Padre, and Price) with high-performance liquid chromatography (HPLC)/electrochemical detection and UV detection. Liquid chromatography/tandem mass spectrometry under identical HPLC conditions was utilized to verify identities of the predominant flavonoids and phenolic acids. Total phenols ranged from 127 (Fritz) to 241 (Padre) mg gallic acid equivalents/100 g of fresh weight. The analyses were compiled to produce a data set of 18 flavonoids and three phenolic acids. The predominant flavonoids were isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-glucoside (in combination), catechin, kaempferol-3-O-rutinoside, epicatechin, quercetin-3-O-galactoside, and isorhamnetin-3-O-galactoside at 16.81, 1.93, 1.17, 0.85, 0.83, and 0.50 mg/100 g of fresh weight almonds, respectively. Using the existing approach of calculating only the aglycone form of flavonoids for use in the U.S. Department of Agriculture nutrient database, whole almonds would provide the most prevalent aglycones of isorhamnetin at 11.70 (3.32), kaempferol at 0.60 (0.17), catechin at 1.93 (0.55), quercetin at 0.72 (0.20), and epicatechin at 0.85 (0.24) mg/100 g of fresh weight (mg/oz serving), respectively. These data can lead to a better understanding of the mechanisms of action underlying the relationship between almond consumption and health-related outcomes and provide values for whole and blanched almonds suitable for inclusion in nutrient databases.

Prooxidant property of green tea polyphenols epicatechin and epigallocatechin-3-gallate: implications for anticancer properties.

PubMed

Azam, S; Hadi, N; Khan, N U; Hadi, S M

2004-10-01

It is believed that anticancer and apoptosis inducing properties of green tea are mediated by it's polyphenolic constituents particularly catechins. A number of reports have shown that green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is among the most effective chemopreventive and apoptosis-inducing agents present in the beverage. Plant polyphenols are naturally occurring antioxidants but they also exhibit prooxidant properties. Over the last several years we have shown that various classes of plant polyphenols including flavonoids, curcuminoids and tannins are capable of catalyzing oxidative DNA cleavage particularly in the presence of transition metal ions such as copper and iron. With a view to understand the chemical basis of various pharmacological properties of green tea, in this paper we have compared the prooxidant properties of green tea polyphenols--EGCG and EC ((-)-epicatechin). The rate of oxidative DNA degradation as well as hydroxyl radical and superoxide anion formation was found to be greater in the case of EGCG as compared with EC. It was also shown that copper mediated oxidation of EC and EGCG possibly leads to the formation of polymerized polyphenols. Further, it was indicated that copper oxidized catechins were more efficient prooxidants as compared with their unoxidized forms. These results correlate with the observation by others that EGCG is the most effective apoptosis inducing polyphenol present in green tea. They are also in support of our hypothesis that prooxidant action of plant polyphenols may be an important mechanism of their anticancer properties. A model for binding of Cu(II) to EC has been presented where the formation of quinone and a quinone methide has been proposed.

Dietary Flavonoid Intake and Lung Cancer—A Population-based Case-control Study

PubMed Central

Cui, Yan; Morgenstern, Hal; Greenland, Sander; Tashkin, Donald P.; Mao, Jenny T.; Cai, Lin; Cozen, Wendy; Mack, Thomas M.; Lu, Qing-Yi; Zhang, Zuo-Feng

2017-01-01

BACKGROUND Laboratory studies suggest that flavonoids are antimutagenic and anticarcinogenic. To investigate the associations between commonly consumed flavonoid compounds and lung cancer, the authors conducted a population-based case–control study of 558 lung cancer cases and a group of 837 controls. METHODS Dietary intakes of flavonoids were estimated by combining the intake frequency (collected by a food frequency questionnaire), portion size, and food composition data. Unconditional logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence limits (95% CLs) with an adjustment for potential confounders, including age, sex, race-ethnicity, years of schooling, smoking status, pack-years of tobacco smoking, and daily energy intake. RESULTS Lung cancer was associated inversely with the consumption of epicatechin (in 10 mg per day increment: OR, 0.64; 95% CL, 0.46–0.88), catechin (4 mg per day increment: OR, 0.49; 95% CL, 0.35–0.70), quercetin (9 mg per day increment: OR, 0.65; 95% CL, 0.44–0.95), and kaempferol (2 mg per day increment: OR, 0.68; 95% CL, 0.51–0.90) among tobacco smokers. There was little association between lung cancer and the flavonoid compounds mentioned above among nonsmokers. Regardless of smoking status, there was little association with total flavonoids: thearubigins, hesperetin, naringenin, and myricetin. In addition, consumption of vegetables, tea, and wine, all of which are rich sources of flavonoids, was associated inversely with lung cancer among tobacco smokers. CONCLUSIONS Certain flavonoid compounds, including epicatechin, catechin, quercetin, and kaempferol, were associated inversely with lung cancer among tobacco smokers, but not among nonsmokers. Further studies of these associations may be warranted. PMID:18327817

A preliminary characterization of Aglianico (Vitis vinifera L. cv.) grape proanthocyanidins and evaluation of their reactivity towards salivary proteins.

PubMed

Rinaldi, A; Jourdes, M; Teissedre, P L; Moio, L

2014-12-01

The flavan-3-ol and proanthocyanidin composition of Aglianico seeds and skins were for the first time determined by HPLC-MS in comparison with the international grapes Merlot and Cabernet Sauvignon. Monomers [(+)-catechin C, (-)-epicatechin EC, (-)-epicatechin-3-O-gallate, ECG] and oligomers [B1, B2, B3, B4 dimers and trimer C1] were identified and quantified in grape extracts. In order to evaluate the reactivity towards salivary proteins of model wine solutions of seeds and skins monomeric/oligomeric and polymeric fractions, the Saliva Precipitation Index (SPI) was carried out. Fractions were also analyzed for their mean degree of polymerization (mDP), percentage of galloylation (%G) and of prodelphinidin (%P) by phloroglucinolysis. Aglianico was the most effective in precipitating proteins than Merlot and Cabernet Sauvignon, mainly for the high percentage of galloylation of grape fractions. The mDP and the percentage of ECG in terminal units resulted to significantly contribute to the precipitation of salivary proteins by grape proanthocyanidins. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exploration of avocado by-products as natural sources of bioactive compounds.

PubMed

Tremocoldi, Maria Augusta; Rosalen, Pedro Luiz; Franchin, Marcelo; Massarioli, Adna Prado; Denny, Carina; Daiuto, Érica Regina; Paschoal, Jonas Augusto Rizzato; Melo, Priscilla Siqueira; Alencar, Severino Matias de

2018-01-01

This study aimed to evaluate the antioxidant, anti-inflammatory, and cytotoxic properties and phenolic composition of peel and seed of avocado varieties Hass and Fuerte using green solvents. Ethanol soluble compounds were identified in peel and seed of both varieties using HPLC-MS/MS and quantified using HPLC-DAD. Agro-industrial by-products of both varieties exhibited high radical scavenging activity against synthetic free radicals (DPPH and ABTS) and reactive oxygen species (peroxyl, superoxide, and hypochlorous acid) and high ability to reduce Fe3+ to Fe2+. The main compounds with significant contribution to the antioxidant activity determined by online HPLC-ABTS●+ analyses were procyanidin B2 and epicatechin in the peel and trans-5-O-caffeoyl-D-quinic acid, procyanidin B1, catechin, and epicatechin in the seed. Peel of Fuerte significantly suppressed TNF-α and nitric oxide (NO) release (459.3 pg/mL and 8.5 μM, respectively), possibly because of the high phenolic content and antioxidant activity detected. Avocado agro-industrial by-products can be used for food and pharmaceutical purposes due to their antioxidant and anti-inflammatory properties.

Exploration of avocado by-products as natural sources of bioactive compounds

PubMed Central

Tremocoldi, Maria Augusta; Rosalen, Pedro Luiz; Franchin, Marcelo; Massarioli, Adna Prado; Denny, Carina; Daiuto, Érica Regina; Paschoal, Jonas Augusto Rizzato; Melo, Priscilla Siqueira

2018-01-01

This study aimed to evaluate the antioxidant, anti-inflammatory, and cytotoxic properties and phenolic composition of peel and seed of avocado varieties Hass and Fuerte using green solvents. Ethanol soluble compounds were identified in peel and seed of both varieties using HPLC-MS/MS and quantified using HPLC-DAD. Agro-industrial by-products of both varieties exhibited high radical scavenging activity against synthetic free radicals (DPPH and ABTS) and reactive oxygen species (peroxyl, superoxide, and hypochlorous acid) and high ability to reduce Fe3+ to Fe2+. The main compounds with significant contribution to the antioxidant activity determined by online HPLC-ABTS●+ analyses were procyanidin B2 and epicatechin in the peel and trans-5-O-caffeoyl-D-quinic acid, procyanidin B1, catechin, and epicatechin in the seed. Peel of Fuerte significantly suppressed TNF-α and nitric oxide (NO) release (459.3 pg/mL and 8.5 μM, respectively), possibly because of the high phenolic content and antioxidant activity detected. Avocado agro-industrial by-products can be used for food and pharmaceutical purposes due to their antioxidant and anti-inflammatory properties. PMID:29444125

Antioxidant capacities of ten edible North American plants.

PubMed

Acuña, Ulyana Muñoz; Atha, Daniel E; Ma, Jun; Nee, Michael H; Kennelly, Edward J

2002-02-01

The EtOAc extract obtained from ten edible North American plants, Acorus calamus, Clintonia borealis, Gaultheria shallon, Juniperus osteosperma, Opuntia polyacantha, Prunus americana, Prunus virginiana, Sambucus cerulea, Sorbus americana and Vaccinium parvifolium, were tested in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical assay. High antioxidant activity was obtained from the extracts of three fruits, Gaultheria shallon, Sambucus cerulea and Prunus americana and one extracted rhizome, Acorus calamus. Catechin and epicatechin, potent polyphenolic antioxidants, were identified in the EtOAc extracts of Gaultheria shallon and Sambucus cerulea by reversed-phase thin-layer chromatography (TLC) and reversed-phase high-performance liquid chromatography (HPLC). Copyright 2002 John Wiley & Sons, Ltd.

Qualitative variation in proanthocyanidin composition of Populus species and hybrids: genetics is the key.

PubMed

Scioneaux, Ashley N; Schmidt, Michael A; Moore, Melissa A; Lindroth, Richard L; Wooley, Stuart C; Hagerman, Ann E

2011-01-01

The literature on proanthocyanidins (tannins) in ecological systems is dominated by quantitative studies. Despite evidence that the qualitative characteristics (subunit type, polymer chain length) of these complex polyphenolics are important determinants of biological activity, little is known about genetic and environmental controls on the type of proanthocyanidins produced by plants. We tested the hypothesis that genetics, season, developmental stage, and environment determine proanthocyanidin qualitative characteristics by using four Populus "cross types" (narrowleaf [P. angustifolia], Fremont [P. fremontii], F1 hybrids, and backcrosses to narrowleaf). We used thiolysis and HPLC analysis to characterize the proanthocyanidins, and found that genetics strongly control composition. The narrowleaf plants accumulate mixed procyanidin/prodelphinidins with average composition epicatechin(11)-epigallocatechin(8)-catechin(2)-catechin((terminal)). Backcross genotypes produce mixed procyanidin/prodelphinidins similar to narrowleaf, while Fremont makes procyanidin dimers, and the F1 plants contain procyanidin heptamers. Less striking effects were noted for genotype × environment, while season and developmental zone had little effect on proanthocyanidin composition or chain length. We discuss the metabolic and ecological consequences of differences in condensed tannin qualitative traits.

Pharmaceutical and nutraceutical effects of Pinus pinaster bark extract

PubMed Central

Iravani, S.; Zolfaghari, B.

2011-01-01

In everyday life, our body generates free radicals and other reactive oxygen species which are derived either from the endogenous metabolic processes (within the body) or from external sources. Many clinical and pharmacological studies suggest that natural antioxidants can prevent oxidative damage. Among the natural antioxidant products, Pycnogenol® (French Pinus pinaster bark extract) has been received considerable attention because of its strong free radical-scavenging activity against reactive oxygen and nitrogen species. P. pinaster bark extract (PBE) contains polyphenolic compounds (these compounds consist of catechin, taxifolin, procyanidins of various chain lengths formed by catechin and epicatechin units, and phenolic acids) capable of producing diverse potentially protective effects against chronic and degenerative diseases. This herbal medication has been reported to have cardiovascular benefits, such as vasorelaxant activity, angiotensin-converting enzyme inhibiting activity, and the ability to enhance the microcirculation by increasing capillary permeability. Moreover, effects on the immune system and modulation of nitrogen monoxide metabolism have been reported. This article provides a brief overview of clinical studies describing the beneficial and health-promoting effects of PBE. PMID:22049273

A study on interactions between the insoluble fractions of different coffee infusions and major cocoa free antioxidants and different coffee infusions and dark chocolate.

PubMed

Çelik, Ecem Evrim; Gökmen, Vural

2018-07-30

This study aimed to investigate the interactions between insoluble fractions of different coffee infusions and major cocoa free antioxidants, catechin and epicatechin, as well as the interactions between different coffee infusions and dark chocolate. Espresso, filtered coffee, French press and Turkish coffee were used for this purpose. Antioxidant capacity (AC) measurements were performed by monitoring the percentage inhibition of 2,2-Diphenyl-1-picrylhydrazil (DPPH) radical. Multivariate approach was adopted for experimental design and data analysis steps. In dry basis, the AC values of infusions (mmol Trolox/kg) were ranged between 953 ± 2.6 and 1184 ± 11.3, while the AC values for their insoluble fractions were ranged between 45 ± 0.0 and 105-1.3. Interactions between the insoluble fractions of coffee infusions and catechins were synergistic for espresso and additive/antagonistic for the other infusions. Interactions between coffee infusions and chocolate were synergistic for French press and Turkish coffee and additive/antagonistic for the other infusions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Phenolic compounds and antioxidant activity of kernels and shells of Mexican pecan (Carya illinoinensis).

PubMed

de la Rosa, Laura A; Alvarez-Parrilla, Emilio; Shahidi, Fereidoon

2011-01-12

The phenolic composition and antioxidant activity of pecan kernels and shells cultivated in three regions of the state of Chihuahua, Mexico, were analyzed. High concentrations of total extractable phenolics, flavonoids, and proanthocyanidins were found in kernels, and 5-20-fold higher concentrations were found in shells. Their concentrations were significantly affected by the growing region. Antioxidant activity was evaluated by ORAC, DPPH•, HO•, and ABTS•-- scavenging (TAC) methods. Antioxidant activity was strongly correlated with the concentrations of phenolic compounds. A strong correlation existed among the results obtained using these four methods. Five individual phenolic compounds were positively identified and quantified in kernels: ellagic, gallic, protocatechuic, and p-hydroxybenzoic acids and catechin. Only ellagic and gallic acids could be identified in shells. Seven phenolic compounds were tentatively identified in kernels by means of MS and UV spectral comparison, namely, protocatechuic aldehyde, (epi)gallocatechin, one gallic acid-glucose conjugate, three ellagic acid derivatives, and valoneic acid dilactone.

Plasma appearance and correlation between coffee and green tea metabolites in human subjects.

PubMed

Renouf, Mathieu; Guy, Philippe; Marmet, Cynthia; Longet, Karin; Fraering, Anne-Lise; Moulin, Julie; Barron, Denis; Dionisi, Fabiola; Cavin, Christophe; Steiling, Heike; Williamson, Gary

2010-12-01

Coffee and green tea are two of the most widely consumed hot beverages in the world. Their respective bioavailability has been studied separately, but absorption of their respective bioactive phenolics has not been compared. In a randomised cross-over design, nine healthy subjects drank instant coffee and green tea. Blood samples were collected over 12 h and at 24 h to assess return to baseline. After green tea consumption, (-)-epigallocatechin (EGC) was the major catechin, appearing rapidly in the plasma; (-)-EGC gallate (EGCg) and (-)-epicatechin (EC) were also present, but (-)-EC gallate and C were not detected. Dihydroferulic acid and dihydrocaffeic acid were the major metabolites that appeared after coffee consumption with a long time needed to reach maximum plasma concentration, suggesting metabolism and absorption in the colon. Other phenolic acid equivalents (caffeic acid (CA), ferulic acid (FA) and isoferulic acid (iFA)) were detected earlier, and they peaked at lower concentrations. Summations of the plasma area under the curves (AUC) for the measured metabolites showed 1.7-fold more coffee-derived phenolic acids than green tea-derived catechins (P = 0.0014). Furthermore, we found a significant correlation between coffee metabolites based on AUC. Inter-individual differences were observed, but individuals with a high level of CA also showed a correspondingly high level of FA. However, no such correlation was observed between the tea catechins and coffee phenolic acids. Correlation between AUC and maximum plasma concentration was also significant for CA, FA and iFA and for EGCg. This implies that the mechanisms of absorption for these two classes of compounds are different, and that a high absorber of phenolic acids is not necessarily a high absorber of catechins.

UHPLC-UV method for the determination of flavonoids in dietary supplements and for evaluation of their antioxidant activities.

PubMed

Magiera, Sylwia; Baranowska, Irena; Lautenszleger, Anna

2015-01-01

A simple and rapid ultra-high performance liquid chromatographic (UHPLC) method coupled with an ultraviolet detector (UV) has been developed and validated for the separation and determination of 14 major flavonoids ((±)-catechin, (-)-epicatechin, glycitin, (-)-epicatechin gallate, rutin, quercitrin, hesperidine, neohesperidine, daidzein, glycitein, quercetin, genistein, hesperetin, and biochanin A) in herbal dietary supplements. The flavonoids have been separated on a Chromolith Fast Gradient Monolithic RP-18e column utilizing a mobile phase composed of 0.05% trifluoroacetic acid in water and acetonitrile in gradient elution mode. Under these conditions, flavonoids were separated in a 5 min run. The selectivity of the developed UHPLC-UV method was confirmed by comparison with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The validation parameters such as linearity, sensitivity, precision, and accuracy were found to be highly satisfactory. The optimized method was applied to determination of flavonoids in different dietary supplements. Additionally, the developed HPLC-UV method combined with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay was used in the evaluation of antioxidant activity of the selected flavonoids. Copyright © 2014 Elsevier B.V. All rights reserved.

Cocoa and Chocolate in Human Health and Disease

PubMed Central

Doughty, Kim; Ali, Ather

2011-01-01

Abstract Cocoa contains more phenolic antioxidants than most foods. Flavonoids, including catechin, epicatechin, and procyanidins predominate in antioxidant activity. The tricyclic structure of the flavonoids determines antioxidant effects that scavenge reactive oxygen species, chelate Fe2+ and Cu+, inhibit enzymes, and upregulate antioxidant defenses. The epicatechin content of cocoa is primarily responsible for its favorable impact on vascular endothelium via its effect on both acute and chronic upregulation of nitric oxide production. Other cardiovascular effects are mediated through anti-inflammatory effects of cocoa polyphenols, and modulated through the activity of NF-κB. Antioxidant effects of cocoa may directly influence insulin resistance and, in turn, reduce risk for diabetes. Further, cocoa consumption may stimulate changes in redox-sensitive signaling pathways involved in gene expression and the immune response. Cocoa can protect nerves from injury and inflammation, protect the skin from oxidative damage from UV radiation in topical preparations, and have beneficial effects on satiety, cognitive function, and mood. As cocoa is predominantly consumed as energy-dense chocolate, potential detrimental effects of overconsumption exist, including increased risk of weight gain. Overall, research to date suggests that the benefits of moderate cocoa or dark chocolate consumption likely outweigh the risks. Antioxid. Redox Signal. 15, 2779–2811. PMID:21470061

The cardiovascular benefits of dark chocolate.

PubMed

Kerimi, Asimina; Williamson, Gary

2015-08-01

Dark chocolate contains many biologically active components, such as catechins, procyanidins and theobromine from cocoa, together with added sucrose and lipids. All of these can directly or indirectly affect the cardiovascular system by multiple mechanisms. Intervention studies on healthy and metabolically-dysfunctional volunteers have suggested that cocoa improves blood pressure, platelet aggregation and endothelial function. The effect of chocolate is more convoluted since the sucrose and lipid may transiently and negatively impact on endothelial function, partly through insulin signalling and nitric oxide bioavailability. However, few studies have attempted to dissect out the role of the individual components and have not explored their possible interactions. For intervention studies, the situation is complex since suitable placebos are often not available, and some benefits may only be observed in individuals showing mild metabolic dysfunction. For chocolate, the effects of some of the components, such as sugar and epicatechin on FMD, may oppose each other, or alternatively in some cases may act together, such as theobromine and epicatechin. Although clearly cocoa provides some cardiovascular benefits according to many human intervention studies, the exact components, their interactions and molecular mechanisms are still under debate. Copyright © 2015 Elsevier Inc. All rights reserved.

Winery by-products: extraction optimization, phenolic composition and cytotoxic evaluation to act as a new source of scavenging of reactive oxygen species.

PubMed

Melo, Priscilla Siqueira; Massarioli, Adna Prado; Denny, Carina; dos Santos, Luciana Ferracini; Franchin, Marcelo; Pereira, Giuliano Elias; Vieira, Thais Maria Ferreira de Souza; Rosalen, Pedro Luiz; de Alencar, Severino Matias

2015-08-15

Nearly 20 million tons of winery by-products, with many biological activities, are discarded each year in the world. The extraction of bioactive compounds from Chenin Blanc, Petit Verdot, and Syrah grape by-products, produced in the semi-arid region in Brazil, was optimized by a Central Composite Rotatable Design. The phenolic compounds profile, antioxidant capacity against synthetic free radicals (DPPH and ABTS), reactive oxygen species (ROS; peroxyl radical, superoxide radical, hypochlorous acid), cytotoxicity assay (MTT) and quantification of TNF-α production in RAW 264.7 cells were conducted. Gallic acid, syringic acid, procyanidins B1 and B2, catechin, epicatechin, epicatechin gallate, quercetin 3-β-d-glucoside, delfinidin 3-glucoside, peonidin 3-O-glucoside, and malvidin 3-glucoside were the main phenolic compounds identified. In general, rachis showed higher antioxidant capacity than pomace extract, especially for Chenin Blanc. All extracts showed low cytotoxicity against RAW 264.7 cells and Petit Verdot pomace suppressed TNF-α liberation in vitro. Therefore, these winery by-products can be considered good sources of bioactive compounds, with great potential for application in the food and pharmaceutical industries. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cocoa and chocolate in human health and disease.

PubMed

Katz, David L; Doughty, Kim; Ali, Ather

2011-11-15

Cocoa contains more phenolic antioxidants than most foods. Flavonoids, including catechin, epicatechin, and procyanidins predominate in antioxidant activity. The tricyclic structure of the flavonoids determines antioxidant effects that scavenge reactive oxygen species, chelate Fe2+ and Cu+, inhibit enzymes, and upregulate antioxidant defenses. The epicatechin content of cocoa is primarily responsible for its favorable impact on vascular endothelium via its effect on both acute and chronic upregulation of nitric oxide production. Other cardiovascular effects are mediated through anti-inflammatory effects of cocoa polyphenols, and modulated through the activity of NF-κB. Antioxidant effects of cocoa may directly influence insulin resistance and, in turn, reduce risk for diabetes. Further, cocoa consumption may stimulate changes in redox-sensitive signaling pathways involved in gene expression and the immune response. Cocoa can protect nerves from injury and inflammation, protect the skin from oxidative damage from UV radiation in topical preparations, and have beneficial effects on satiety, cognitive function, and mood. As cocoa is predominantly consumed as energy-dense chocolate, potential detrimental effects of overconsumption exist, including increased risk of weight gain. Overall, research to date suggests that the benefits of moderate cocoa or dark chocolate consumption likely outweigh the risks.

Extracts of Phenolic Compounds from Seeds of Three Wild Grapevines—Comparison of Their Antioxidant Activities and the Content of Phenolic Compounds

PubMed Central

Weidner, Stanisław; Powałka, Anna; Karamać, Magdalena; Amarowicz, Ryszard

2012-01-01

Phenolic compounds were extracted from three wild grapevine species: Vitis californica, V. riparia and V. amurensis seeds using 80% methanol or 80% acetone. The total content of phenolic compounds was determined utilizing the Folin-Ciocalteu’s phenol reagent while the content of tannins was assayed with the vanillin and BSA precipitation methods. Additionally, the DPPH free radical scavenging activity and the reduction power of the extracts were measured. The RP-HPLC method was applied to identify the phenolic compounds in the extracts, such as phenolic acids and catechins. The seeds contained large amounts of tannins, catechins and gallic acid and observable quantities of p-coumaric acid. The total content of phenolic compounds and tannins was similar in the extracts from V. californica and V. riparia seeds. However, the total content of total phenolic compounds and tannins in the extracts from V. californica and V. riperia seeds were about two-fold higher than that in the extracts from V. amurensis seeds. Extracts from seeds of the American species (V. californica and V. riparia) contained similarly high concentrations of tannins, whereas extracts from seeds of V. amurensis had approximately half that amount of these compounds. The content of catechin and epicatechin was similar in all extracts. The highest DPPH• anti-radical scavenging activity was observed in the acetonic and methanolic extracts of V. californica and V. riparia seeds— while the acetonic extract from the V. californica seeds was the strongest reducing agent. PMID:22489161

Specific dietary polyphenols attenuate atherosclerosis in apolipoprotein E-knockout mice by alleviating inflammation and endothelial dysfunction.

PubMed

Loke, Wai Mun; Proudfoot, Julie M; Hodgson, Jonathan M; McKinley, Allan J; Hime, Neil; Magat, Maria; Stocker, Roland; Croft, Kevin D

2010-04-01

Animal and clinical studies have suggested that polyphenols in fruits, red wine, and tea may delay the development of atherosclerosis through their antioxidant and anti-inflammatory properties. We investigated whether individual dietary polyphenols representing different polyphenolic classes, namely quercetin (flavonol), (-)-epicatechin (flavan-3-ol), theaflavin (dimeric catechin), sesamin (lignan), or chlorogenic acid (phenolic acid), reduce atherosclerotic lesion formation in the apolipoprotein E (ApoE)(-/-) gene-knockout mouse. Quercetin and theaflavin (64-mg/kg body mass daily) significantly attenuated atherosclerotic lesion size in the aortic sinus and thoracic aorta (P<0.05 versus ApoE(-/-) control mice). Quercetin significantly reduced aortic F(2)-isoprostane, vascular superoxide, vascular leukotriene B(4), and plasma-sP-selectin concentrations; and augmented vascular endothelial NO synthase activity, heme oxygenase-1 protein, and urinary nitrate excretion (P<0.05 versus control ApoE(-/-) mice). Theaflavin showed similar, although less extensive, significant effects. Although (-)-epicatechin significantly reduced F(2)-isoprostane, superoxide, and endothelin-1 production (P<0.05 versus control ApoE(-/-) mice), it had no significant effect on lesion size. Sesamin and chlorogenic acid treatments exerted no significant effects. Quercetin, but not (-)-epicatechin, significantly increased the expression of heme oxygenase-1 protein in lesions versus ApoE(-/-) controls. Specific dietary polyphenols, in particular quercetin and theaflavin, may attenuate atherosclerosis in ApoE(-/-) gene-knockout mice by alleviating inflammation, improving NO bioavailability, and inducing heme oxygenase-1. These data suggest that the cardiovascular protection associated with diets rich in fruits, vegetables, and some beverages may in part be the result of flavonoids, such as quercetin.

Screening and identification of antioxidants in biological samples using high-performance liquid chromatography-mass spectrometry and its application on Salacca edulis Reinw.

PubMed

Shui, Guanghou; Leong, Lai Peng

2005-02-23

In this study, a new approach was developed for screening and identifying antioxidants in biological samples. The approach was based on significant decreases of the intensities of ion peaks obtained from high-performance liquid chromatography (HPLC) coupled with mass spectrometry (MS) upon reaction with 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals. HPLC-MS/MS was further applied to elucidate structures of antioxidant peaks characterized in a spiking test. The new approach could also be used to monitor the reactivity of antioxidants in biological sample with free radicals. The approach was successfully applied to the identification of antioxidants in salak (Salacca edulis Reinw), a tropical fruit that is reported to be a very good source of natural antioxidants, but it was still not clear which compounds were responsible for its antioxidant property. The antioxidants in salak were identified to be chlorogenic acid, (-)-epicatechin, and singly linked proanthocyanidins that mainly existed as dimers through hexamers of catechin or epicatechin. In salak, chlorogenic acid was identified to be an antioxidant of the slow reaction type as it reacted with free radicals much more slowly than either (-)-epicatechin or proanthocyanidins. The new approach was proved to be useful for the characterization and identification of antioxidants in biological samples as a mass detector combined with an HPLC separation system not only serves as an ideal tool to monitor free radical active components but also provides their possible chemical structures in a biological sample.

Isolation of phenolic compounds from hop extracts using polyvinylpolypyrrolidone: characterization by high-performance liquid chromatography-diode array detection-electrospray tandem mass spectrometry.

PubMed

Magalhães, Paulo J; Vieira, Joana S; Gonçalves, Luís M; Pacheco, João G; Guido, Luís F; Barros, Aquiles A

2010-05-07

The aim of the present work was the development of a suitable methodology for the separation and determination of phenolic compounds in the hop plant. The developed methodology was based on the sample purification by adsorption of phenolic compounds from the matrix to polyvinylpolypyrrolidone (PVPP) and subsequent desorption of the adsorbed polyphenols with acetone/water (70:30, v/v). At last, the extract was analyzed by HPLC-DAD and HPLC-ESI-MS/MS. The first phase of this work consisted of the study of the adsorption behavior of several classes of phenolic compounds (e.g. phenolic acids, flavonols, and flavanols) by PVPP in model solutions. It has been observed that the process of adsorption of the different phenolic compounds to PVPP (at low concentrations) is differentiated, depending on the structure of the compound (number of OH groups, aromatic rings, and stereochemistry hindrance). For example, within the phenolic acids class (benzoic, p-hydroxybenzoic, protocatechuic and gallic acids) the PVPP adsorption increases with the number of OH groups of the phenolic compound. On the other hand, the derivatization of OH groups (methylation and glycosylation) resulted in a greatly diminished binding. The use of PVPP revealed to be very efficient for adsorption of several phenolic compounds such as catechin, epicatechin, xanthohumol and quercetin, since high adsorption and recovery values were obtained. The methodology was further applied for the extraction and isolation of phenolic compounds from hops. With this methodology, it was possible to obtain high adsorption values (>or=80%) and recovery yield values (>or=70%) for the most important phenolic compounds from hops such as xanthohumol, catechin, epicatechin, quercetin and kaempferol glycosides, and in addition it allows the identification of about 30 phenolic compounds by HPLC-DAD and HPLC-ESI-MS/MS. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Polyphenol profiles of French cider apple varieties (Malus domestica sp.).

PubMed

Sanoner, P; Guyot, S; Marnet, N; Molle, D; Drilleau, J P

1999-12-01

The cortex of 14 French apple varieties (12 cider and 2 juice varieties), one English cider variety, and one dessert apple (i.e., Golden Delicious) were studied for their polyphenol composition. Total polyphenols were assayed by the Folin-Ciocalteu method, and the precise polyphenolic composition (monomeric catechins, proanthocyanidins, hydroxycinnamic acids, and dihydrochalcones) was obtained by HPLC following thiolysis. ESI-MS and ESI-MS/MS analyses showed that chlorogenic acid and p-coumaroylquinic acid were methylated under the conditions of thiolysis. Depending on the variety, the global polyphenol concentration varied from 1 to 7 g per kilogram of fresh cortex. Cider varieties globally showed a higher polyphenol concentration than the dessert apple Golden Delicious, bitter varieties being the more concentrated. The proportion of the polyphenol classes varied greatly from one cultivar to another. For all varieties, procyanidins were always the predominant class. They were mainly constituted of (-)-epicatechin units with a small proportion of (+)-catechin as a terminal unit. The average degree of polymerization ranged between 4.2 and 7.5 depending upon the variety with an exception for the sharp varieties Guillevic and Avrolles which showed significant concentrations of procyanidins with DPn of 40 and 50, respectively.

Population Variability of Main Secondary Metabolites in Hypericum lydium Boiss. (Hypericaceae)

PubMed Central

Çirak, Cüneyt; Radusiene, Jolita; Ivanauskas, Liudas; Jakstas, Valdas; Çamaş, Necdet

2015-01-01

In the present study, we investigated the variation in the content of naphthodianthrones hypericin and pseudohypericin, phloroglucinol derivatives hyperforin and adhyperforin, the phenolic acids as chlorogenic acid, neochlorogenic acid, 2,4-dihydroxybenzoic acid, and the flavonols, namely, hyperoside, isoquercitrin, quercitrin, quercetin, avicularin, rutin, (+)-catechin and (-)-epicatechin, and biflavonoid amentoflavone among wild H. lydium Boiss. populations from five different growing sites of Turkey for the first time. The aerial parts representing a total of 30 individuals were collected at full flowering and dissected into floral, leaf and stem tissues. After dried at room temperature, the plant materials were assayed for chemical contents by HPLC. The populations varied significantly in the content of chemical compounds. Among different plant parts, flowers were found to be main repository site of hyperforin, adhyperforin, hypericin, pseudohypericin, amentoflavone, quercetin, avicularin, rutin and (+)-catechin accumulations whereas rest of the compounds tested were accumulated primarily in leaves in all growing localities. The stems were the least accumulative organ that did not yield hyperforin, adhyperforin and rutin. The chemical diversity among the populations and plant parts is discussed as being possibly the result of different environmental, morphological and genetic factors. PMID:26330888

Bitterness in wine.

PubMed

Noble, A C

1994-12-01

Bitterness in wine is elicited primarily by flavonoid phenols, which are bitter and astringent, and by ethanol. Monomeric flavonoid phenols are primarily bitter but as the molecular weight increases upon polymerization, astringency increases more rapidly than bitterness. The chiral difference between the two wine flavan-3-ol monomers produces a significant difference in temporal perception of bitterness: (-)-epicatechin is significantly more bitter and had significantly longer duration of bitterness than (+)-catechin. Ethanol enhances bitterness intensity and duration, whereas varying wine pH has little or no effect on perceived bitterness. Whereas PROP status had no significant effect on temporal perception of bitterness or astringency, subjects with low salivary flow rates took longer to reach maximum bitterness and astringency intensity and reported longer persistence of both attributes than high-flow subjects.

Molecular Interactions between (−)-Epigallocatechin Gallate Analogs and Pancreatic Lipase

PubMed Central

Wang, Shihui; Sun, Zeya; Dong, Shengzhao; Liu, Yang; Liu, Yun

2014-01-01

The molecular interactions between pancreatic lipase (PL) and four tea polyphenols (EGCG analogs), like (−)-epigallocatechin gallate (EGCG), (−)-gallocatechin gallate (GCG), (−)-epicatechin gallate (ECG), and (−)-epigallocatechin (EC), were studied from PL activity, conformation, kinetics and thermodynamics. It was observed that EGCG analogs inhibited PL activity, and their inhibitory rates decreased by the order of EGCG>GCG>ECG>EC. PL activity at first decreased rapidly and then slowly with the increase of EGCG analogs concentrations. α-Helix content of PL secondary structure decreased dependent on EGCG analogs concentration by the order of EGCG>GCG>ECG>EC. EGCG, ECG, and EC could quench PL fluorescence both dynamically and statically, while GCG only quenched statically. EGCG analogs would induce PL self-assembly into complexes and the hydrodynamic radii of the complexes possessed a close relationship with the inhibitory rates. Kinetics analysis showed that EGCG analogs non-competitively inhibited PL activity and did not bind to PL catalytic site. DSC measurement revealed that EGCG analogs decreased the transition midpoint temperature of PL enzyme, suggesting that these compounds reduced PL enzyme thermostability. In vitro renaturation through urea solution indicated that interactions between PL and EGCG analogs were weak and non-covalent. PMID:25365042

Flavanol Quantification of Grapes via Multiple Reaction Monitoring Mass Spectrometry. Application to Differentiation among Clones of Vitis vinifera L. cv. Rufete Grapes.

PubMed

García-Estévez, Ignacio; Alcalde-Eon, Cristina; Escribano-Bailón, M Teresa

2017-08-09

The determination of the detailed flavanol composition in food matrices is not a simple task because of the structural similarities of monomers and, consequently, oligomers and polymers. The aim of this study was the development and validation of an HPLC-MS/MS-multiple reaction monitoring (MRM) method that would allow the accurate and precise quantification of catechins, gallocatechins, and oligomeric proanthocyanidins. The high correlation coefficients of the calibration curves (>0.993), the recoveries not statistically different from 100%, the good intra- and interday precisions (<5%), and the LOD and LOQ values, low enough to quantify flavanols in grapes, are good results from the method validation procedure. Its usefulness has also been tested by determining the detailed composition of Vitis vinifera L. cv. Rufete grapes. Seventy-two (38 nongalloylated and 34 galloylated) and 53 (24 procyanidins and 29 prodelphinidins) flavanols have been identified and quantified in grape seed and grape skin, respectively. The use of HCA and PCA on the detailed flavanol composition has allowed differentiation among Rufete clones.

Characterization of Phenolic Compounds in Wine Lees

PubMed Central

Zhijing, Ye; Shavandi, Amin; Harrison, Roland; Bekhit, Alaa El-Din A.

2018-01-01

The effect of vinification techniques on phenolic compounds and antioxidant activity of wine lees are poorly understood. The present study investigated the antioxidant activity of white and red wine lees generated at early fermentation and during aging. In this study, the total phenol content (TPC), total tannin content (TTC), mean degree of polymerization (mDP), and antioxidant activities of five white and eight red wine lees samples from different vinification backgrounds were determined. The results showed that vinification techniques had a significant (p < 0.05) impact on total phenol and tannin content of the samples. White wine lees had high mDP content compared with red ones. Catechin (50–62%) and epicatechin contents were the predominant terminal units of polymeric proanthocyanidin extracted from examined samples. Epigallocatechin was the predominant extension unit of white wine lees, whereas epicatechin was the predominant compound in red wine marc. The ORAC (oxygen radical absorbance capacity) assay was strongly correlated with the DPPH (α,α-diphenyl-β-picrylhydrazyl) assay, and the results showed the strong antioxidant activities associated with red wine lees (PN > 35 mg Trolox/g FDM) (PN: Pinot noir lees; FDM: Freeze-dried Material). This study indicates that tannin is one of the major phenolic compounds available in wine lees that can be useful in human and animal health applications. PMID:29587406

Characterization of Phenolic Compounds in Wine Lees.

PubMed

Zhijing, Ye; Shavandi, Amin; Harrison, Roland; Bekhit, Alaa El-Din A

2018-03-25

The effect of vinification techniques on phenolic compounds and antioxidant activity of wine lees are poorly understood. The present study investigated the antioxidant activity of white and red wine lees generated at early fermentation and during aging. In this study, the total phenol content (TPC), total tannin content (TTC), mean degree of polymerization (mDP), and antioxidant activities of five white and eight red wine lees samples from different vinification backgrounds were determined. The results showed that vinification techniques had a significant ( p < 0.05) impact on total phenol and tannin content of the samples. White wine lees had high mDP content compared with red ones. Catechin (50-62%) and epicatechin contents were the predominant terminal units of polymeric proanthocyanidin extracted from examined samples. Epigallocatechin was the predominant extension unit of white wine lees, whereas epicatechin was the predominant compound in red wine marc. The ORAC (oxygen radical absorbance capacity) assay was strongly correlated with the DPPH (α, α-diphenyl-β-picrylhydrazyl) assay, and the results showed the strong antioxidant activities associated with red wine lees (PN > 35 mg Trolox/g FDM) (PN: Pinot noir lees; FDM: Freeze-dried Material). This study indicates that tannin is one of the major phenolic compounds available in wine lees that can be useful in human and animal health applications.

Preparation of Clinically Useful Sennoside-reduced Rhubarb.

PubMed

Arai, Makoto; Nakada, Yoshinobu; Kajiwara, Kagemasa; Kimura, Minoru; Ishii, Naoaki

2016-03-20

The aim of this study was to develop a method of removing sennoside to reduce the cathartic effect of rhubarb while conserving its other pharmacological activities. Rhubarb powder was steam autoclaved at 121°C and 0.14 MPa for 20, 60, or 120 minutes, and HPLC analysis was conducted to determine levels of rhubarb components. Mice were fed non-autoclaved or 20-minute-autoclaved rhubarb extracts. Feces were collected and weighed over a 24-hour period. India ink was orally administered to determine the distance of fecal migration through the intestinal tract. Autoclaving 20, 60, and 120 minutes decreased sennoside A and B to trace levels but only autoclaving 20 minutes conserved most of the (+)-catechin, (-)-epicatechin, and (-)-epicatechin gallate contents (i.e., 69%, 90%, 88%, respectively). Therefore only rhubarb autoclaved for 20 minutes was used in subsequent experiments. Fecal output (in g) in mice treated with water (control), autoclaved rhubarb, and non-autoclaved rhubarb was 2.78 ± 0.07, 3.30 ± 0.13 (p = 0.348), and 3.81 ± 0.07 (p = 0.005). India ink migration was far less in mice treated with autoclaved rhubarb vs non-autoclaved rhubarb. Steam autoclaving the rhubarb for 20 minutes reduces sennoside levels and its cathartic activity while conserving its other pharmacological activities.

Polyphenol levels in human urine after intake of six different polyphenol-rich beverages.

PubMed

Ito, Hideyuki; Gonthier, Marie-Paule; Manach, Claudine; Morand, Christine; Mennen, Louise; Rémésy, Christian; Scalbert, Augustin

2005-10-01

Dietary polyphenols are suggested to participate in the prevention of CVD and cancer. It is essential for epidemiological studies to be able to compare intake of the main dietary polyphenols in populations. The present paper describes a fast method suitable for the analysis of polyphenols in urine, selected as potential biomarkers of intake. This method is applied to the estimation of polyphenol recovery after ingestion of six different polyphenol-rich beverages. Fifteen polyphenols including mammalian lignans (enterodiol and enterolactone), several phenolic acids (chlorogenic, caffeic, m-coumaric, gallic, and 4-O-methylgallic acids), phloretin and various flavonoids (catechin, epicatechin, quercetin, isorhamnetin, kaempferol, hesperetin, and naringenin) were simultaneously quantified in human urine by HPLC coupled with electrospray ionisation mass-MS (HPLC-electrospray-tandem mass spectrometry) with a run time of 6 min per sample. The method has been validated with regard to linearity, precision, and accuracy in intra- and inter-day assays. It was applied to urine samples collected from nine volunteers in the 24 h following consumption of either green tea, a grape-skin extract, cocoa beverage, coffee, grapefruit juice or orange juice. Levels of urinary excretion suggest that chlorogenic acid, gallic acid, epicatechin, naringenin or hesperetin could be used as specific biomarkers to evaluate the consumption of coffee, wine, tea or cocoa, and citrus juices respectively.

Characterization of Date (Deglet Nour) Seed Free and Bound Polyphenols by High-Performance Liquid Chromatography-Mass Spectrometry.

PubMed

Sirisena, Sameera; Zabaras, Dimitrios; Ng, Ken; Ajlouni, Said

2017-02-01

Date (Pheonix dactylifera L.) seeds are a valuable and abundant by-product with various potential food applications. Free polyphenols (FPPs) and bound polyphenols (BPPs) of date seeds from Deglet Nour variety grown in Australia were investigated using high-performance liquid chromatography-mass spectrometry. The FPP fraction contained the following main phenolic compounds per gram of date seed powder; procyanidin B1 (499.8 ± 7.8 μg), procyanidin B2 (288.6 ± 6.1 μg), catechin (167.6 ± 2.1 μg), epicatechin (39.44 ± 0.39 μg), and protocatechuic acid (1.77 ± 0.22 μg). Additionally, one of the 2 A-type dimers was confirmed as procyanidin A2 (24.05 ± 0.12 μg/g). A-type dimers have not been reported before in date seeds. The BPP fraction contained epicatechin (52.59 ± 0.76 μg/g) and procyanidin B2 (294.2 ± 3.7 μg/g), while several peaks exhibiting ESI - m/z of 153 indicated dihydroxybenzoic acid isomers including protocatechuic acid (2.138 ± 0.025 μg/g). These findings contributed to our knowledge of date seed phytochemicals and understanding of their contribution to the reported bioactivities. © 2017 Institute of Food Technologists®.

[Rapid analysis on phenolic compounds in Rheum palmatum based on UPLC-Q-TOF/MSE combined with diagnostic ions filter].

PubMed

Wang, Qing; Lu, Zhi-Wei; Liu, Yue-Hong; Wang, Ming-Ling; Fu, Shuang; Zhang, Qing-Qing; Zhao, Hui-Zhen; Zhang, Zhi-Xin; Xie, Zi-Ye; Huang, Zheng-Hai; Yu, Hong-Hong; Zhou, Wen-Juan; Gao, Xiao-Yan

2017-05-01

Diagnostic ions filter method was used to rapidly detect and identify the phenolic compounds in Rheum palmatum based on ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MSE). The representative authentic standards of phenolic compounds, including gallic acid, (+)-catechin, (－)-epicatechin, (－)-epicatechin-3-O-gallate and procyanidin B2, were subjected to analysis by UPLC-Q-TOF/MSE system with negative ion mode. Fragmentation patterns of each standard were summarized based on assigned fragment ions. The prominent product ions were selected as diagnostic ions. Subsequently, diagnostic ions filter was employed to rapidly recognize analogous skeletons. Combined with retention time, accurate mass, characteristic fragments and previous literature data, the structures of the filtered compounds were identified or tentatively characterized. A total 63 phenolic compounds (36 phenolic acid derivatives, 8 flavonoid derivatives and 19 tennis derivatives) in R. palmatum were identified, including 6 potential new compounds. The method of diagnostic ions filter could rapidly detect and identify phenolic compounds in R. palmatum This study provides a method for rapid detection of phenolic compounds in R. palmatum and is expected to complete the material basis of rhubarb. Copyright© by the Chinese Pharmaceutical Association.

Procyanidins from apples (Malus pumila Mill.) extend the lifespan of Caenorhabditis elegans.

PubMed

Sunagawa, Tadahiro; Shimizu, Takahiko; Kanda, Tomomasa; Tagashira, Motoyuki; Sami, Manabu; Shirasawa, Takuji

2011-01-01

Apple polyphenols (AP) mainly consist of procyanidins (PC), which are composed of (-)-epicatechins and (+)-catechins. In order to investigate the antiageing effects of PC, we measured the lifespan of CAENORHABDITIS ELEGANS worms treated with PC. Treatment with 65 µg/mL PC extended the mean lifespan of wild-type N2 and FEM-1 worms by 12.1 % and 8.4 %, respectively, i.e., to a similar extent as resveratrol. In addition, treatment with 100 µg/mL AP also significantly prolonged the mean lifespan of the same worms by 12.0 % and 5.3 %, respectively, i.e., to a similar extent as PC. In contrast, treatment with (-)-epicatechin did not extend the lifespan of the worms. PC did not modify the growth, food intake, or fecundity of C. elegans. Treatment with PC did not extend the lifespan of MEV-1 worms, which show excessive oxidative stress, indicating that PC had no antioxidant ability in the MEV-1 mutant. Moreover, treatment with PC had no effect on the longevity of SIR-2.1 worms, which lack the activity of SIR-2, a member of the sirtuin family of NAD (+)-dependent protein deacetylases. These results indicated that PC has SIR-2.1-dependent antiageing effects on C. elegans. © Georg Thieme Verlag KG Stuttgart · New York.

The polyphenolics in the aqueous extract of Psidium guajava kinetically reveal an inhibition model on LDL glycation.

PubMed

Chen, Kuan-Chou; Chuang, Chao-Ming; Lin, Li-Yun; Chiu, Wen-Ta; Wang, Hui-Er; Hsieh, Chiu-Lan; Tsai, Tsuimin; Peng, Robert Y

2010-01-01

Guava [Psidium guajava L. (Myrtaceae)] budding leaf extract (PE) has shown tremendous bioactivities. Previously, we found seven major compounds in PE, i.e., gallic acid, catechin, epicatechin, rutin, quercetin, naringenin, and kaempferol. PE showed a potentially active antiglycative effect in an LDL (low density lipoprotein) mimic biomodel, which can be attributed to its large content of polyphenolics. The glycation and antiglycative reactions showed characteristic distinct four-phase kinetic patterns. In the presence of PE, the kinetic coefficients were 0.000438, 0.000060, 0.000, and -0.0001354 ABS-mL/mg-min, respectively, for phases 1 to 4. Computer simulation evidenced the dose-dependent inhibition model. Conclusively, PE contains a large amount of polyphenolics, whose antiglycative bioactivity fits the inhibition model.

Statistical mixture design selective extraction of compounds with antioxidant activity and total polyphenol content from Trichilia catigua.

PubMed

Lonni, Audrey Alesandra Stinghen Garcia; Longhini, Renata; Lopes, Gisely Cristiny; de Mello, João Carlos Palazzo; Scarminio, Ieda Spacino

2012-03-16

Statistical design mixtures of water, methanol, acetone and ethanol were used to extract material from Trichilia catigua (Meliaceae) barks to study the effects of different solvents and their mixtures on its yield, total polyphenol content and antioxidant activity. The experimental results and their response surface models showed that quaternary mixtures with approximately equal proportions of all four solvents provided the highest yields, total polyphenol contents and antioxidant activities of the crude extracts followed by ternary design mixtures. Principal component and hierarchical clustering analysis of the HPLC-DAD spectra of the chromatographic peaks of 1:1:1:1 water-methanol-acetone-ethanol mixture extracts indicate the presence of cinchonains, gallic acid derivatives, natural polyphenols, flavanoids, catechins, and epicatechins. Copyright © 2011 Elsevier B.V. All rights reserved.

Pine Bark and Green Tea Concentrated Extracts: Antioxidant Activity and Comprehensive Characterization of Bioactive Compounds by HPLC–ESI-QTOF-MS

PubMed Central

Cádiz-Gurrea, María de la Luz; Fernández-Arroyo, Salvador; Segura-Carretero, Antonio

2014-01-01

The consumption of polyphenols has frequently been associated with low incidence of degenerative diseases. Most of these natural antioxidants come from fruits, vegetables, spices, grains and herbs. For this reason, there has been increasing interest in identifying plant extract compounds. Polymeric tannins and monomeric flavonoids, such as catechin and epicatechin, in pine bark and green tea extracts could be responsible for the higher antioxidant activities of these extracts. The aim of the present study was to characterize the phenolic compounds in pine bark and green tea concentrated extracts using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC–ESI-QTOF-MS). A total of 37 and 35 compounds from pine bark and green tea extracts, respectively, were identified as belonging to various structural classes, mainly flavan-3-ol and its derivatives (including procyanidins). The antioxidant capacity of both extracts was evaluated by three complementary antioxidant activity methods: Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Higher antioxidant activity values by each method were obtained. In addition, total polyphenol and flavan-3-ol contents, which were determined by Folin–Ciocalteu and vanillin assays, respectively, exhibited higher amounts of gallic acid and (+)-catechin equivalents. PMID:25383680

Carotenoids, Phenolic Profile, Mineral Content and Antioxidant Properties in Flesh and Peel of Prunus persica Fruits during Two Maturation Stages.

PubMed

Dabbou, Samia; Maatallah, Samira; Castagna, Antonella; Guizani, Monia; Sghaeir, Wala; Hajlaoui, Hichem; Ranieri, Annamaria

2017-03-01

Carotenoids and phenolic profile, antioxidant activity as well as concentrations of selected macronutrients (K, N, Mg, Ca and Na) and micronutrients (Zn, Cu and Mn) in flesh and peel of peach fruit were recorded at two harvest dates. Predominant mineral was potassium, followed by calcium, magnesium and sodium. The concentration of most micronutrients was greater in the peel than in the flesh especially in early season. The concentration of most elements in flesh and peel decreased during fruit maturation. Total carotenoids content varied with respect to the cultivar. β-cryptoxanthin and β-carotene were the major carotenoids in both tissues and flesh contain the lowest amounts. Neochlorogenic acid, chlorogenic acid, catechin, epicatechin, gallic acid, rutin, quercetin-3-O-galactoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, were detected in both peel and flesh, with chlorogenic acid and catechin being the predominant components. Peel extracts showed markedly higher antioxidant activities, when estimated by ABTS or DPPH assays, than the flesh counterparts, consistent with the observed higher phenolic content. Overall, total phenolics levels increased at full ripening stage in both peel and flesh. The results found herein provide important data on carotenoids, phenolic and macro- and micronutrient changes during fruit growth, and emphases peach fruit as a potential functional food.

Pine bark and green tea concentrated extracts: antioxidant activity and comprehensive characterization of bioactive compounds by HPLC-ESI-QTOF-MS.

PubMed

de la Luz Cádiz-Gurrea, María; Fernández-Arroyo, Salvador; Segura-Carretero, Antonio

2014-11-06

The consumption of polyphenols has frequently been associated with low incidence of degenerative diseases. Most of these natural antioxidants come from fruits, vegetables, spices, grains and herbs. For this reason, there has been increasing interest in identifying plant extract compounds. Polymeric tannins and monomeric flavonoids, such as catechin and epicatechin, in pine bark and green tea extracts could be responsible for the higher antioxidant activities of these extracts. The aim of the present study was to characterize the phenolic compounds in pine bark and green tea concentrated extracts using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-QTOF-MS). A total of 37 and 35 compounds from pine bark and green tea extracts, respectively, were identified as belonging to various structural classes, mainly flavan-3-ol and its derivatives (including procyanidins). The antioxidant capacity of both extracts was evaluated by three complementary antioxidant activity methods: Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Higher antioxidant activity values by each method were obtained. In addition, total polyphenol and flavan-3-ol contents, which were determined by Folin-Ciocalteu and vanillin assays, respectively, exhibited higher amounts of gallic acid and (+)-catechin equivalents.

Separation of catechins and methylxanthines in tea samples by capillary electrochromatography.

PubMed

Uysal, Ulku Dilek; Aturki, Zeineb; Raggi, Maria Augusta; Fanali, Salvatore

2009-04-01

In this paper, the simultaneous separation of several polyphenols such as (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, theophylline, caffeine in green and black teas by capillary electrochromatography (CEC) was developed. Several experimental parameters such as stationary phase type, mobile phase composition, buffer and pH, inner diameter of the columns, sample injection, were evaluated to obtain the complete separation of the analysed compounds. Baseline resolution of the studied polyphenols was achieved within 30 min by using a capillary column (id 100 microm) packed with bidentate C(18) particles for 24.5 cm and a mobile phase composed of 5 mM ammonium acetate buffer pH 4 with H(2)O/ACN (80:20, v/v). The applied voltage and the temperature were set at 30 kV and 20 degrees C. Precision, detection and quantification limits, linearity, and accuracy were investigated. A good linearity (R(2) > 0.9992) was achieved over a concentration working range of 2-100 microg/mL for all the analytes. LOD and LOQ were 1 and 2 microg/mL, respectively, for all studied compounds. The CEC method was applied to the analysis of those polyphenols in green and black tea samples after an extraction procedure. Good recovery data from accuracy studies ranged between 90% and 112% for all analytes.

Hepatoprotective and hypoglycemic effects of a tannin rich extract from Ximenia americana var. caffra root.

PubMed

Sobeh, Mansour; Mahmoud, Mona F; Abdelfattah, Mohamed A O; El-Beshbishy, Hesham A; El-Shazly, Assem M; Wink, Michael

2017-09-15

Liver diseases and diabetes are serious health disorders associated with oxidative stress and ageing. Some plant polyphenols can lower the risk of these diseases. We investigated the phytochemical profiling of a root extract from Ximenia americana var. caffra using HPLC-PDA-ESI-MS/MS. The antioxidant activities in vitro were investigated. The hepatoprotective activities were studied in rat models with d-galactosamine (d-GaIN)-induced hepatotoxicity and the antidiabetic activities in STZ-diabetic rats were also investigated. HPLC-PDA-ESI-MS/MS was used to identify plant phenolics. The antioxidant activities in vitro were determined using DPPH and FRAP assays. The in vivo hepatoprotective activities were determined for d-GaIN-induced hepatotoxicity in rats. We determined the liver markers alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT), liver peroxidation product malondialdehyde (MDA), glutathione content (GSH), albumin and total bilirubin concentration. The histopathological changes in rat liver were also studied. The antidiabetic activities were also investigated in STZ-diabetic rats and serum glucose, serum insulin hormone, and lipid peroxides were determined. The root extract is rich in tannins with 20 compounds including a series of stereoisomers of (epi)catechin, (epi)catechin-(epi)catechin, (epi)catechin-(epi)catechin-(epi)catechin, and their galloyl esters. Promising antioxidant potential was observed in vitro in DPPH assay with EC 50 of 6.5 µg extract / 26 µg raw material and in FRAP assay with 19.54 mM FeSO 4 compared with ascorbic acid (EC 50 of 2.92 µg/ml) and quercetin (FeSO 4 24.04 mM/mg), respectively. Significant reduction of serologic enzymatic markers and hepatic oxidative stress markers such as ALT, AST, MDA, GGT, and total bilirubin, as well as elevation of GSH and albumin were observed in rats with d-galactosamine-induced liver damage treated with the extract. These findings agree with a histopathological examination suggesting a hepatoprotective potential for the root extract. The root extract can mediate an antidiabetic effect by reducing elevated blood glucose and serum lipid peroxides levels and by increasing insulin in STZ-diabetic rats by -107, -31.1, +11.3%, respectively. The results of this study suggest that the tannin-rich extract from Ximenia americana var. caffra could be an interesting candidate for the treatment of several health disorders associated with oxidative stress such as hepatocellular injury and diabetes. Copyright © 2017. Published by Elsevier GmbH.

Chocolate Matrix Factors Modulate Pharmacokinetic Behavior of Cocoa Flavan-3-Ol Phase-II Metabolites Following Oral Consumption by Sprague-Dawley Rats

PubMed Central

Neilson, Andrew P.; Sapper, Teryn N.; Janle, Elsa M.; Rudolph, Ralf; Matusheski, Nathan V.; Ferruzzi, Mario G.

2010-01-01

The impact of carbohydrates and milk on the bioavailability of catechin (C) and epicatechin (EC) from chocolate has been previously studied. However, little data exists regarding potential modulation of the phase-II metabolism by these chocolate matrix factors. The objectives of this study were to assess the impact of matrix composition on qualitative and quantitative profiles of circulating catechins and their metabolites following administration of commercially relevant chocolate confections. Sprague-Dawley rats were fed 1.5 g of a confection (reference dark, high sucrose, or milk chocolate) by intragastric gavage, and plasma samples were collected over 8 h. HPLC-MS analysis was performed to quantify C, EC and their metabolites. The predominant metabolites were O-glucuronides (2 metabolites), and O-Me-O-glucuronides (3 metabolites). Plasma concentrations of metabolites were generally the highest for high sucrose treatment and lowest for milk treatment, while reference dark treatment generally resulted in intermediate concentrations. The O-Me-(±)-C/EC-O-β-glucuronide (peak 4) was significantly higher for the high sucrose treatment (2325 nM*h) versus the milk treatment (1300 nM*h). Additionally, CMAX values for (±)-C/EC-O-β-glucuronide (peak 3), and two O-Me-(±)-C/EC-O-β-glucuronides (peaks 4 and 6) were significantly higher for high sucrose treatment (4012, 518, and 2518 nM, respectively) versus the milk treatment (2590, 240, and 1670 nM, respectively). Milk and sucrose appear to modulate both metabolism and plasma pharmacokinetics, and to a lesser extent, the overall bioavailability of catechins from chocolate confections. PMID:20446738

Chocolate matrix factors modulate the pharmacokinetic behavior of cocoa flavan-3-ol phase II metabolites following oral consumption by Sprague-Dawley rats.

PubMed

Neilson, Andrew P; Sapper, Teryn N; Janle, Elsa M; Rudolph, Ralf; Matusheski, Nathan V; Ferruzzi, Mario G

2010-06-09

The impact of carbohydrates and milk on the bioavailability of catechin (C) and epicatechin (EC) from chocolate has been previously studied. However, little data exist regarding potential modulation of the phase II metabolism by these chocolate matrix factors. The objectives of this study were to assess the impact of matrix composition on qualitative and quantitative profiles of circulating catechins and their metabolites following administration of commercially relevant chocolate confections. Sprague-Dawley rats were administered 1.5 g of a confection (reference dark, high sucrose, or milk chocolate) by intragastric gavage, and plasma samples were collected over 8 h. High-performance liquid chromatography-mass spectrometry analysis was performed to quantify C, EC, and their metabolites. The predominant metabolites were O-glucuronides (two metabolites) and O-Me-O-glucuronides (three metabolites). Plasma concentrations of metabolites were generally the highest for high sucrose treatment and lowest for milk treatment, while the reference dark treatment generally resulted in intermediate concentrations. The O-Me-(+/-)-C/EC-O-beta-glucuronide (peak 4) was significantly higher for the high sucrose treatment (2325 nM h) versus the milk treatment (1300 nM h). Additionally, C(MAX) values for (+/-)-C/EC-O-beta-glucuronide (peak 3) and two O-Me-(+/-)-C/EC-O-beta-glucuronides (peaks 4 and 6) were significantly higher for the high sucrose treatment (4012, 518, and 2518 nM, respectively) versus the milk treatment (2590, 240, and 1670 nM, respectively). Milk and sucrose appear to modulate both metabolism and plasma pharmacokinetics and, to a lesser extent, the overall bioavailability of catechins from chocolate confections.

Milk decreases urinary excretion but not plasma pharmacokinetics of cocoa flavan-3-ol metabolites in humans.

PubMed

Mullen, William; Borges, Gina; Donovan, Jennifer L; Edwards, Christine A; Serafini, Mauro; Lean, Michael E J; Crozier, Alan

2009-06-01

Cocoa drinks containing flavan-3-ols are associated with many health benefits, and conflicting evidence exists as to whether milk adversely affects the bioavailability of flavan-3-ols. The objective was to determine the effect of milk on the bioavailability of cocoa flavan-3-ol metabolites. Nine human volunteers followed a low-flavonoid diet for 2 d before drinking 250 mL of a cocoa beverage, made with water or milk, that contained 45 micromol (-)-epicatechin and (-)-catechin. Plasma and urine samples were collected for 24 h, and flavan-3-ol metabolites were analyzed by HPLC with photodiode array and mass spectrometric detection. Milk affected neither gastric emptying nor the transit time through the small intestine. Two flavan-3-ol metabolites were detected in plasma and 4 in urine. Milk had only minor effects on the plasma pharmacokinetics of an (epi)catechin-O-sulfate and had no effect on an O-methyl-(epi)catechin-O-sulfate. However, milk significantly lowered the excretion of 4 urinary flavan-3-ol metabolites from 18.3% to 10.5% of the ingested dose (P = 0.016). Studies that showed protective effects of cocoa and those that showed no effect of milk on bioavailability used products that have a much higher flavan-3-ol content than does the commercial cocoa used in the present study. Most studies of the protective effects of cocoa have used drinks with a very high flavan-3-ol content. Whether similar protective effects are associated with the consumption of many commercial chocolate and cocoa products containing substantially lower amounts of flavan-3-ols, especially when absorption at lower doses is obstructed by milk, remains to be determined.

High-throughput method based on quick, easy, cheap, effective, rugged and safe followed by liquid chromatography-multi-wavelength detection for the quantification of multiclass polyphenols in wines.

PubMed

Fontana, Ariel R; Bottini, Rubén

2014-05-16

In this work, a reliable, simple, fast, inexpensive and robust sample preparation approach for the determination of multiclass polyphenols in wine samples is proposed. The polyphenols selected for this work were gallic acid, (+)-catechin, (-)-epicatechin, caffeic acid, syringic acid, coumaric acid, ferulic acid, trans-resveratrol, quercetin and cinnamic acid. The method is based on QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction technique coupled with dispersive solid-phase extraction (d-SPE) clean-up. Under optimized conditions, the analytes were extracted from 5mL wine samples (previously acidified with 1% formic acid) using 2.5mL acetonitrile. For phase separation, 1.5g NaCl and 4g anhydrous MgSO4 were added. Then, a 1mL aliquot of the partitioned supernatant was cleaned-up using d-SPE with a combination of 150mg CaCl2, 50mg primary-secondary amine (PSA) and 50mgC18 as sorbents. A 250μL aliquot of the obtained cleaned extract was concentrated to dryness and taken up with the initial mobile phase previous to liquid chromatography-multi-wavelength detection (LC-MWD). The proposed method provided limits of detection (LODs) ranging from 0.004 to 0.079μgmL(-1) and an inter-day variability below 12% RSD for all analytes in red and white wine samples. Considering external calibration (red wines) and matrix-matched calibration (white wines) as quantification techniques, the overall recoveries (accuracy) of the method ranged between 75.0% and 119.6% for red and white wine samples, respectively. The developed method was applied for the determination of polyphenols in 10 wines produced in Argentina. Nine phenolic compounds were determined, at concentrations above detectable levels in the method. The maximum concentrations corresponded to (-)-epicatechin in white wines, while gallic acid and (+)-catechin were the most abundant in red wines. Copyright © 2014 Elsevier B.V. All rights reserved.

DNA Protecting Activities of Nymphaea nouchali (Burm. f) Flower Extract Attenuate t-BHP-Induced Oxidative Stress Cell Death through Nrf2-Mediated Induction of Heme Oxygenase-1 Expression by Activating MAP-Kinases

PubMed Central

Ju, Mi-Kyoung

2017-01-01

This study was performed to investigate the antioxidant activities of Nymphaea nouchali flower (NNF) extract and the underlying mechanism using RAW 264.7 cells. The presence of gallic acid, catechin, epicatechin, epigallocatechin, epicatechin gallate, caffeic acid, quercetin, and apigenin in the NNF was confirmed by high-performance liquid chromatography (HPLC). The extract had a very potent capacity to scavenge numerous free radicals. NNF extract was also able to prevent DNA damage and quench cellular reactive oxygen species (ROS) generation induced by tert-Butyl hydroperoxide (t-BHP) with no signs of toxicity. The NNF extract was able to augment the expression of both primary and phase II detoxifying enzyme, resulting in combat the oxidative stress. This is accomplished by phosphorylation of mitogen-activated protein kinase (MAP kinase) (p38 kinase and extracellular signal-regulated kinase (ERK)) followed by enhancing the nuclear translocation of the nuclear factor erythroid 2-related factor 2 (Nrf2). This attenuates cellular ROS generation and confers protection from cell death. Altogether, the results of current study revealed that Nymphaea nouchali flower could be a source of natural phytochemicals that could lead to the development of new therapeutic agents for preventing oxidative stress associated diseases and attenuating disease progression. PMID:28956831

Membrane lipids protected from oxidation by red wine tannins: a proton NMR study.

PubMed

Furlan, Aurélien L; Jobin, Marie-Lise; Buchoux, Sébastien; Grélard, Axelle; Dufourc, Erick J; Géan, Julie

2014-12-01

Dietary polyphenols widespread in vegetables and beverages like red wine and tea have been reported to possess antioxidant properties that could have positive effects on human health. In this study, we propose a new in situ and non-invasive method based on proton liquid-state nuclear magnetic resonance (NMR) to determine the antioxidant efficiency of red wine tannins on a twice-unsaturated phospholipid, 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLiPC), embedded in a membrane model. Four tannins were studied: (+)-catechin (C), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG). The lipid degradation kinetics was determined by measuring the loss of the bis-allylic protons during oxidation induced by a radical initiator, 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH). The antioxidant efficiency, i.e. the ability of tannins to slow down the lipid oxidation rate, was shown to be higher for galloylated tannins, ECG and EGCG. Furthermore, the mixture of four tannins was more efficient than the most effective tannin, EGCG, demonstrating a synergistic effect. To better understand the antioxidant action mechanism of polyphenols on lipid membranes, the tannin location was investigated by NMR and molecular dynamics. A correlation between antioxidant action of tannins and their location at the membrane interface (inserted at the glycerol backbone level) could thus be established. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Chemical profiling of guarana seeds (Paullinia cupana) from different geographical origins using UPLC-QTOF-MS combined with chemometrics.

PubMed

da Silva, Givaldo Souza; Canuto, Kirley Marques; Ribeiro, Paulo Riceli Vasconcelos; de Brito, Edy Sousa; Nascimento, Madson Moreira; Zocolo, Guilherme Julião; Coutinho, Janclei Pereira; de Jesus, Raildo Mota

2017-12-01

Paullinia cupana, commonly known as guarana, is an Amazonian fruit whose seeds are used to produce the powdered guarana, which is rich in caffeine and consumed for its stimulating activity. The metabolic profile of guarana from the two largest producing regions was investigated using UPLC-MS combined with multivariate statistical analysis. The principal component analysis (PCA) showed significant differences between samples produced in the states of Bahia and Amazonas. The metabolites responsible for the differentiation were identified by orthogonal partial least squares discriminant analysis (OPLS-DA). Fourteen phenolic compounds were characterized in guarana powder samples, and catechin, epicatechin, B-type procyanidin dimer, A-type procyanidin trimer and A-type procyanidin dimer were the main compounds responsible for the geographical variation of the samples. Copyright © 2017. Published by Elsevier Ltd.

Identification of proanthocyanidin dimers and trimers, flavone C-Glycosides, and antioxidants in Ficus deltoidea , a malaysian herbal tea.

PubMed

Omar, Maizatul Hasyima; Mullen, William; Crozier, Alan

2011-02-23

Phenolic compounds in an aqueous infusion of leaves of Ficus deltoidea (Moraceae), a well-known herbal tea in Malaysia, were analyzed by HPLC coupled to photodiode array and fluorescence detectors and an electrospray ionization tandem mass spectrometer. Following chromatography of extracts on a reversed phase C(12) column, 25 flavonoids were characterized and/or tentatively identified with the main constituents being flavan-3-ol monomers, proanthocyanidins, and C-linked flavone glycosides. The proanthocyanidins were dimers and trimers comprising (epi)catechin and (epi)afzelechin units. No higher molecular weight proanthocyanidin polymers were detected. The antioxidant activity of F. deltoidea extract was analyzed using HPLC with online antioxidant detection. This revealed that 85% of the total antioxidant activity of the aqueous F. deltoidea infusion was attributable to the flavan-3-ol monomers and the proanthocyanidins.

Chemical Composition and Bioactivities of Two Common Chaenomeles Fruits in China: Chaenomeles speciosa and Chaenomeles sinensis.

PubMed

Miao, Jing; Zhao, Chengcheng; Li, Xia; Chen, Xuetao; Mao, Xinhui; Huang, Hanhan; Wang, Tingting; Gao, Wenyuan

2016-08-01

Contents of total flavonoids, total phenolics, total triterpenes, total condensed tannin and total saponins in peels, flesh and endocarps of Chaenomeles speciosa (CSP) and Chaenomeles sinensis (CSS) were determined by colorimetric method, while 5 phenolics (vanillic, gallic, chlorogenic, ferulic and p-coumaric acids), 2 triterpenes (oleanolic and ursolic acids), and 3 flavonoids (rutin, catechin and epicatechin) were identified and quantified by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and HPLC, and antioxidant and α-glucosidase inhibitory activities of them also were evaluated as well as their digestive characteristics. In the correlation analysis, total phenolics, vanillic acid, catechin, ursolic acid and oleanolic acid all contribute to DPPH(·) scavenge capacity, gallic acid contributes to total ferric reducing antioxidant power, while total triterpenes, total saponins, chlorogenic acid and ferullic acid contribute to α-glucosidase inhibitory activity. In the principal component analysis, endocarps of CSP and CSS both show better quality than their peels and flesh, respectively. In vitro digestion can increase contents of total flavonoids, total condensed tannin and total saponins, while contents of total phenolics and total triterpenes decreased greatly. Our study would contribute to the full use of discarded parts of the 2 Chaenomeles and be helpful to establish a good foundation for further research of CSP and CSS. © 2016 Institute of Food Technologists®

Multivariate statistical analysis of the polyphenolic constituents in kiwifruit juices to trace fruit varieties and geographical origins.

PubMed

Guo, Jing; Yuan, Yahong; Dou, Pei; Yue, Tianli

2017-10-01

Fifty-one kiwifruit juice samples of seven kiwifruit varieties from five regions in China were analyzed to determine their polyphenols contents and to trace fruit varieties and geographical origins by multivariate statistical analysis. Twenty-one polyphenols belonging to four compound classes were determined by ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry. (-)-Epicatechin, (+)-catechin, procyanidin B1 and caffeic acid derivatives were the predominant phenolic compounds in the juices. Principal component analysis (PCA) allowed a clear separation of the juices according to kiwifruit varieties. Stepwise linear discriminant analysis (SLDA) yielded satisfactory categorization of samples, provided 100% success rate according to kiwifruit varieties and 92.2% success rate according to geographical origins. The result showed that polyphenolic profiles of kiwifruit juices contain enough information to trace fruit varieties and geographical origins. Copyright © 2017 Elsevier Ltd. All rights reserved.

Potential of Fruit Wastes as Natural Resources of Bioactive Compounds

PubMed Central

Deng, Gui-Fang; Shen, Chen; Xu, Xiang-Rong; Kuang, Ru-Dan; Guo, Ya-Jun; Zeng, Li-Shan; Gao, Li-Li; Lin, Xi; Xie, Jie-Feng; Xia, En-Qin; Li, Sha; Wu, Shan; Chen, Feng; Ling, Wen-Hua; Li, Hua-Bin

2012-01-01

Fruit wastes are one of the main sources of municipal waste. In order to explore the potential of fruit wastes as natural resources of bioactive compounds, the antioxidant potency and total phenolic contents (TPC) of lipophilic and hydrophilic components in wastes (peel and seed) of 50 fruits were systematically evaluated. The results showed that different fruit residues had diverse antioxidant potency and the variation was very large. Furthermore, the main bioactive compounds were identified and quantified, and catechin, cyanidin 3-glucoside, epicatechin, galangin, gallic acid, homogentisic acid, kaempferol, and chlorogenic acid were widely found in these residues. Especially, the values of ferric-reducing antioxidant power (FRAP), trolox equivalent antioxidant capacity (TEAC) and TPC in the residues were higher than in pulps. The results showed that fruit residues could be inexpensive and readily available resources of bioactive compounds for use in the food and pharmaceutical industries. PMID:22942704

Potential of fruit wastes as natural resources of bioactive compounds.

PubMed

Deng, Gui-Fang; Shen, Chen; Xu, Xiang-Rong; Kuang, Ru-Dan; Guo, Ya-Jun; Zeng, Li-Shan; Gao, Li-Li; Lin, Xi; Xie, Jie-Feng; Xia, En-Qin; Li, Sha; Wu, Shan; Chen, Feng; Ling, Wen-Hua; Li, Hua-Bin

2012-01-01

Fruit wastes are one of the main sources of municipal waste. In order to explore the potential of fruit wastes as natural resources of bioactive compounds, the antioxidant potency and total phenolic contents (TPC) of lipophilic and hydrophilic components in wastes (peel and seed) of 50 fruits were systematically evaluated. The results showed that different fruit residues had diverse antioxidant potency and the variation was very large. Furthermore, the main bioactive compounds were identified and quantified, and catechin, cyanidin 3-glucoside, epicatechin, galangin, gallic acid, homogentisic acid, kaempferol, and chlorogenic acid were widely found in these residues. Especially, the values of ferric-reducing antioxidant power (FRAP), trolox equivalent antioxidant capacity (TEAC) and TPC in the residues were higher than in pulps. The results showed that fruit residues could be inexpensive and readily available resources of bioactive compounds for use in the food and pharmaceutical industries.

Comparing procyanidins in selected Vaccinium species by UHPLC-MS(2) with regard to authenticity and health effects.

PubMed

Jungfer, Elvira; Zimmermann, Benno F; Ruttkat, Axel; Galensa, Rudolf

2012-09-26

Cranberry procyanidins have been associated with an effect against urinary tract infections (UTI) for decades, and European health claims are requested. This study compares the procyanidin profiles and concentrations of American cranberry ( Vaccinium macrocarpon Ait.), European cranberry ( Vaccinium oxycoccus L.), and lingonberry ( Vaccinium vitis-idaea L.) analyzed using ultrahigh-performance liquid chromatoraphy coupled to a triple-quadrupole mass spectrometer with electrospray interface (UHPLC-MS(2)). Concentrations of A-type trimers, procyanidin A2, catechin, epicatechin, and B-type dimers and trimers have been evaluated and compared for the first time in the three berries. The data clearly show remarkable differences in the procyanidin profiles and concentrations, especially the lack of A-type trimers in V. oxycoccus; thus, the effectiveness against UTI may vary among the Vaccinium species. These differences can be used to prove authenticity.

Peroxynitrite induced formation of the neurotoxins 5-S-cysteinyl-dopamine and DHBT-1: implications for Parkinson's disease and protection by polyphenols.

PubMed

Vauzour, David; Ravaioli, Giulia; Vafeiadou, Katerina; Rodriguez-Mateos, Ana; Angeloni, Cristina; Spencer, Jeremy P E

2008-08-15

Mechanisms of nigral cell injury in Parkinson's disease remain unclear, although a combination of increased oxidative stress, the formation of catecholamine-quinones and the subsequent formation of neurotoxic cysteinyl-catecholamine conjugates may contribute. In the present study, peroxynitrite was observed to generate both 2-S- and 5-S-cysteinyl-dopamine and a dihydrobenzothiazine species, DHBT-1, following the reaction of dopamine with l-cysteine. The formation of 5-S-cysteinyl-dopamine and DHBT-1 in the presence of peroxynitrite induced significant neuronal injury. Pre-treatment of cortical neurons with pelargonidin, quercetin, hesperetin, caffeic acid, the 4'-O-Me derivatives of catechin and epicatechin (0.1-3.0 microM) resulted in concentration dependant protection against 5-S-cysteinyl-dopamine-induced neurotoxicity. These data suggest that polyphenols may protect against neuronal injury induced by endogenous neurotoxins relevant to the aetiology of the Parkinson disease.

Proanthocyanidins from grape seeds promote proliferation of mouse hair follicle cells in vitro and convert hair cycle in vivo.

PubMed

Takahashi, T; Kamiya, T; Yokoo, Y

1998-11-01

For the purpose of discovering natural products which possess hair growing activity, we examined about 1000 kinds of plant extracts concerning growth-promoting activity with respect to hair follicle cells. After an extensive search, we discovered that proanthocyanidins extracted from grape seeds promote proliferation of hair follicle cells isolated from mice by about 230% relative to controls (100%); and that proanthocyanidins possess remarkable hair-cycle-converting activity from the telogen phase to the anagen phase in C3H mice in vivo test systems. The profile of the active fraction of the proanthocyanidins was elucidated by thiolytic degradation and tannase hydrolysis. We found that the constitutive monomers were epicatechin and catechin; and that the degree of polymerization was 3.5. We demonstrated the possibility of using the proanthocyanidins extracted from grape seeds as agents inducing hair growth.

Characterization of polyphenols and evaluation of antioxidant capacity in grape pomace of the cv. Malbec.

PubMed

Antoniolli, Andrea; Fontana, Ariel R; Piccoli, Patricia; Bottini, Rubén

2015-07-01

Low molecular weight polyphenols (LMW-PPs) and anthocyanins, along with the antioxidant capacity, were assessed in grape pomace extract (GPE) of red grape (Vitis vinifera L.) cv. Malbec. Twenty-six phenolics (13 LMW-PPs and 13 anthocyanins) were characterized and quantified by HPLC-MWD and UPLC-ESI-MS. The maximum concentrations of LMW-PPs corresponded to the flavanols (+)-catechin and (-)-epicatechin, whereas malvidin-3-glucoside was the most abundant anthocyanin. Piceatannol, a stilbene analogue to resveratrol with higher antioxidant activity, was firstly identified and quantified in GPE of the cv. Malbec. The antioxidant activity for Malbec GPE determined by oxygen radical absorbance capacity (ORAC) assay was 2,756 μmol TEg(-1) GPE. Therefore, the data reported sustain the use of winemaking by-products as a cheap source of phenolic compounds suitable for biotechnological applications, as a strategy for sustainable oenology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Determination of phenolic constituents of biological interest in red wine by capillary electrophoresis with electrochemical detection.

PubMed

Peng, Youyuan; Chu, Qingcui; Liu, Fanghua; Ye, Jiannong

2004-01-28

A simultaneous determination of trans-resveratrol, (-)-epicatechin, and (+)-catechin in red wine by capillary electrophoresis with electrochemical detection (CE-ED) is reported. The effects of the potential of the working electrode, pH and concentration of running buffer, separation voltage, and injection time on CE-ED were investigated. Under the optimum conditions, the analytes could be separated in a 100 mmol/L borate buffer (pH 9.2) within 20 min. A 300 microm diameter carbon disk electrode has a good response at +0.85 V (vs SCE) for all analytes. The response was linear over 3 orders of magnitude with detection limit (S/N = 3) ranging from 2 x 10(-7) to 5 x 10(-7) g/mL for all analytes. This method has been used for the determination of these analytes in red wine without enrichment, and the assay result was satisfactory.

Compositional and sensory characterization of red wine polymers.

PubMed

Wollmann, Nadine; Hofmann, Thomas

2013-03-06

After isolation from red wine by means of ultrafiltration and gel adsorption chromatography, the composition of the highly astringent tasting high-molecular weight polymers was analyzed by means of HPLC-MS/MS, HPLC-UV/vis, and ion chromatography after thiolytic, alkaline, and acidic depolymerization and, on the basis of the quantitative data obtained as well as model incubation experiments, key structural features of the red wine polymers were proposed. The structural backbone of the polymers seems to be comprised of a procyanidin chain with (-)-epicatechin, (+)-catechin, (-)-epicatechin-3-O-gallate units as extension and terminal units as well as (-)-epigallocatechin as extension units. In addition, acetaldehyde was shown to link different procyanidins at the A-ring via an 1,1-ethylene bridge and anthocyanins and pyranoanthocyanins were found to be linked to the procyanidin backbone via a C-C-linkage at position C(6) or C(8), respectively. Alkaline hydrolysis demonstrated the polymeric procyanidins to be esterified with various organic acids and phenolic acids, respectively. In addition, the major part of the polysaccharides present in the red wine polymeric fraction were found not to be covalently linked to procyanidins. Interestingly, sensory evaluation of individual fractions of the red wine polymers did not show any significant difference in the astringent threshold concentrations, nor in the astringency intensity in supra-threshold concentrations and demonstrated the mean degree of polymerization as well as the galloylation degree not to have an significant influence on the astringency perception.

Grape variety effect on proanthocyanidin composition and sensory perception of skin and seed tannin extracts from bordeaux wine grapes (Cabernet Sauvignon and Merlot) for two consecutive vintages (2006 and 2007).

PubMed

Chira, Kleopatra; Schmauch, Gregory; Saucier, Cédric; Fabre, Sandy; Teissedre, Pierre-Louis

2009-01-28

Grape variety [Cabernet Sauvignon (CS) and Merlot (M)] effect on the proanthocyanidin composition and sensory perception of wine grapes from Bordeaux vineyards for two successive vintages (2006 and 2007) is reported. The flavan-3-ol monomers [(+)-catechin = C, (-)-epicatechin = EC, (-)-epicatechin-O-gallatte = ECG] and the proanthocyanidin oligomers [dimers B1, B2, B3, and B4 and trimer Cat-Cat-Epi (T)] in grape seed and skin tannin extracts were identified and quantified at harvest. Proanthocyanidin subunit compositions, percentage of galloylation (%G), and percentage of prodelphinidins (%P) as well as mean degree of polymerization (mDP) of the proanthocyanidin fraction were determined. Sensory analysis concerning the astringency and bitterness intensity of the proanthocyanidins of skin and seed tannin extracts was also performed. The results showed that proanthocyanidin composition can be greatly affected by grape variety. For both vintages between CS and M, significant differences were found on mDP (p < 0.05) in seed tannin extracts, whereas in skin tannin extracts, significant differences were observed for %G and %P (p < 0.05). Sensory analysis showed that grape variety influenced neither astringency nor bitterness intensity perception for both skin and seed tannin extracts for the two successive vintages studied. A positive correlation was found between astringency intensity, mDP, and B3 content in skin tannin extracts.

An analysis method for flavan-3-ols using high performance liquid chromatography coupled with a fluorescence detector.

PubMed

Wang, Liuqing; Yamashita, Yoko; Saito, Akiko; Ashida, Hitoshi

2017-07-01

Procyanidins belong to a family of flavan-3-ols, which consist of monomers, (+)-catechin and (-)-epicatechin, and their oligomers and polymers, and are distributed in many plant-derived foods. Procyanidins are reported to have many beneficial physiological activities, such as antihypertensive and anticancer effects. However, the bioavailability of procyanidins is not well understood owing to a lack of convenient and high-sensitive analysis methods. The aim of this study was to develop an improved method for determining procyanidin content in both food materials and biological samples. High performance liquid chromatography (HPLC) coupled with a fluorescence detector was used in this study. The limits of detection (LODs) of (+)-catechin, (-)-epicatechin, procyanidin B2, procyanidin C1, and cinnamtannin A2 were 3.0×10 -3  ng, 4.0×10 -3  ng, 14.0×10 -3  ng, 18.5×10 -3  ng, and 23.0×10 -3  ng, respectively; the limits of quantification (LOQs) were 10.0×10 -3  ng, 29.0×10 -3  ng, 28.5×10 -3  ng, 54.1×10 -3  ng, and 115.0×10 -3  ng, respectively. The LOD and LOQ values indicated that the sensitivity of the fluorescence detector method was around 1000 times higher than that of conventional HPLC coupled with a UV-detector. We applied the developed method to measure procyanidins in black soybean seed coat extract (BE) prepared from soybeans grown under three different fertilization conditions, namely, conventional farming, basal manure application, and intertillage. The amount of flavan-3-ols in these BEs decreased in the order intertillage > basal manure application > conventional farming. Commercially available BE was orally administered to mice at a dose of 250 mg/kg body weight, and we measured the blood flavan-3-ol content. Data from plasma analysis indicated that up to the tetramer oligomerization, procyanidins were detectable and flavan-3-ols mainly existed in conjugated forms in the plasma. In conclusion, we developed a highly sensitive and convenient analytical method for the analysis of flavan-3-ols, and applied this technique to investigate the bioavailability of flavan-3-ols in biological samples and to measure flavan-3-ol content in food material and plants. Copyright © 2017. Published by Elsevier B.V.

Antifungal Properties of Crude Extracts, Fractions, and Purified Compounds from Bark of Curatella americana L. (Dilleniaceae) against Candida Species

PubMed Central

Mendes de Toledo, Cleyton Eduardo; Santos, Patrícia Regina; Palazzo de Mello, João Carlos; Dias Filho, Benedito Prado; Ueda-Nakamura, Tânia

2015-01-01

The ethnomedicinal plant Curatella americana L. (Dilleniaceae) is a common shrub in the Brazilian cerrado, in which crude extract showed antifungal activity in a preliminary study. In this work, the antifungal and cytotoxic properties of the crude extract, fractions, and isolated compounds from C. americana were evaluated against the standard yeast strains Candida albicans, C. tropicalis, and C. parapsilosis, clinical isolates, and fluconazole-resistant strains. The combinatory effects between subfractions and isolated compounds and effects on cell morphology, virulence factors, and exogenous ergosterol were also evaluated. The MIC obtained against the Candida species including fluconazole-resistant strain ranged from 15.3 to 31.3 µg/mL for crude extract, 3.9 to 15.6 µg/mL for ethyl acetate fraction, and 7.8 to 31.3 µg/mL for subfractions. The isolated compounds identified as 4′-O-methyl-catechin, epicatechin-3-O-gallate, and 4′-O-methyl-catechin-3-O-gallate showed lower antifungal activity than the crude extract and fractions (MIC ranging from 31.3 to 125.0 µg/mL). The addition of exogenous ergosterol to yeast culture did not interfere in the antifungal activity of the extract and its fractions. Synergistic antifungal activity was observed between subfractions and isolated compounds. The effects on virulence factors and the different mechanisms of action compared to fluconazole and nystatin suggest that this ethnomedicinal plant may be an effective alternative treatment for candidiasis. PMID:26347790

Isolation and Characterization of cDNAs Encoding Leucoanthocyanidin Reductase and Anthocyanidin Reductase from Populus trichocarpa

PubMed Central

Lu, Wanxiang; Yang, Li; Karim, Abdul; Luo, Keming

2013-01-01

Proanthocyanidins (PAs) contribute to poplar defense mechanisms against biotic and abiotic stresses. Transcripts of PA biosynthetic genes accumulated rapidly in response to infection by the fungus Marssonina brunnea f.sp. multigermtubi, treatments of salicylic acid (SA) and wounding, resulting in PA accumulation in poplar leaves. Anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR) are two key enzymes of the PA biosynthesis that produce the main subunits: (+)-catechin and (−)-epicatechin required for formation of PA polymers. In Populus, ANR and LAR are encoded by at least two and three highly related genes, respectively. In this study, we isolated and functionally characterized genes PtrANR1 and PtrLAR1 from P. trichocarpa. Phylogenetic analysis shows that Populus ANR1 and LAR1 occurr in two distinct phylogenetic lineages, but both genes have little difference in their tissue distribution, preferentially expressed in roots. Overexpression of PtrANR1 in poplar resulted in a significant increase in PA levels but no impact on catechin levels. Antisense down-regulation of PtrANR1 showed reduced PA accumulation in transgenic lines, but increased levels of anthocyanin content. Ectopic expression of PtrLAR1 in poplar positively regulated the biosynthesis of PAs, whereas the accumulation of anthocyanin and flavonol was significantly reduced (P<0.05) in all transgenic plants compared to the control plants. These results suggest that both PtrANR1 and PtrLAR1 contribute to PA biosynthesis in Populus. PMID:23741362

Capillary liquid chromatography-mass spectrometry for the rapid identification and quantification of almond flavonoids.

PubMed

Hughey, Christine A; Wilcox, Bruce; Minardi, Carina S; Takehara, Chiyo W; Sundararaman, Meenakshi; Were, Lilian M

2008-05-30

A rapid negative ion ESI high-performance capillary liquid chromatography-mass spectrometry method was developed to identify and quantify flavonoids (e.g., flavanols, flavonols, flavanones and glycosides). Fifteen standards and two varieties of almond skin extract powder (Carmel and Nonpareil) were used to demonstrate the chromatographic separation, reproducibility and accuracy of the method that employed a 150 mm x 0.3 mm ChromXP 3C18-EP-120 column. All standards eluted in less than 10 min, providing a 9-12x reduction in analysis time compared to existing methods (90-120 min). However, isomers (e.g., catechin/epicatechin and galactosides/glucosides) were not resolved and, therefore, identified and quantified collectively. RSDs for retention time and peak area reproducibility (mass spectrometry data) were <0.5% and <5.0%, respectively. Peak area reproducibility was greatly improved (from a RSD>10%) after the implementation of a low-flow metal needle in the ESI source. Quantitation by mass spectrometry also afforded a % error less than 5% for most compounds.

Spatial and Temporal Localization of Flavonoid Metabolites in Strawberry Fruit (Fragaria × ananassa).

PubMed

Crecelius, Anna C; Hölscher, Dirk; Hoffmann, Thomas; Schneider, Bernd; Fischer, Thilo C; Hanke, Magda-Viola; Flachowsky, Henryk; Schwab, Wilfried; Schubert, Ulrich S

2017-05-03

Flavonoids are important metabolites in strawberries (Fragaria × ananassa) because they accomplish an extensive collection of physiological functions and are valuable for human health. However, their localization within the fruit tissue has not been extensively explored. Matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was employed to shed light on the spatial distribution of flavonoids during fruit development. One wild-type (WT) and two transgenic lines were compared, wherein the transgenic enzymes anthocyanidin reductase (ANRi) and flavonol synthase (FLSi), respectively, were down-regulated using an RNAi-based silencing approach. In most cases, fruit development led to a reduction of the investigated flavonoids in the fruit tissue; as a consequence, they were exclusively present in the skin of mature red fruits. In the case of (epi)catechin dimer, both the ANRi and the WT phenotypes revealed low levels in mature red fruits, whereas the ANRi line bore the lowest relative concentration, as analyzed by liquid chromatography-electrospray ionization multiple-step mass spectrometry (LC-ESI-MS n ).

The relationship between antiglycation activity and procyanidin and phenolic content in commercial grape seed products.

PubMed

Sun, Cathy; McIntyre, Kristina; Saleem, Ammar; Haddad, Pierre Selim; Arnason, John Thor

2012-02-01

Eight commercial grape seed products (GSPs) were assessed for their inhibition of the formation of advanced glycation end-products in vitro. All 8 commercial GSPs included in this study were potent inhibitors of advanced glycation end-product formation with IC(50) values ranging from 2.93 to 20.0 µg/mL. Total procyanidin content ranged from 60% to 73%. HPLC-DAD-ELSD results indicate that (+)-catechin, (-)-epicatechin, procyanidin B1, and procyanidin B2 were predominant and ubiquitously present in all the products under study, while gallic acid and procyanidin B4 were present in relatively minor amounts. The IC(50) values correlated with total phenolic content, and multiple regression analysis indicated that IC(50) is a linear function of the concentration of gallic acid and procyanidins B1, B2, and B4. Based on this study, GSPs have the potential to complement conventional diabetes medication toward disease management and prevention.

Polyphenols of Carménère Grapes

PubMed Central

Huamán-Castilla, Nils Leander; Mariotti-Celis, María Salomé; Pérez-Correa, José Ricardo

2017-01-01

Carménère is the emblematic grape of Chile. Recent studies indicate that it has a different polyphenolic profile than other commercial varieties of grape among other factors, due to its long maturation period. The grape and wine of Carménère stand out for having high concentrations of anthocyanins (malvidin), flavonols (quercetin and myricetin) and flavanols (catechin, epicatechin and epigallocatechin). These compounds are related to the distinctive characteristic of Carménère wine regarding astringency and color. In vivo and in vitro models suggest some positive effects of these polyphenols in the treatment and prevention of chronic diseases, such as atherosclerosis and cancer. Therefore, there is a high level of interest to develop scalable industrial methods in order to obtain and purify Carménère grape polyphenol extracts that could be used to improve the characteristics of wines from other varieties or produce nutraceuticals or functional foods for preventing and treating various chronic diseases. PMID:28845147

Foliar Desiccators Glyphosate, Carfentrazone, and Paraquat Affect the Technological and Chemical Properties of Cowpea Grains.

PubMed

Lindemann, Igor da Silva; Lang, Gustavo Heinrich; Hoffmann, Jessica Fernanda; Rombaldi, Cesar Valmor; de Oliveira, Maurício; Elias, Moacir Cardoso; Vanier, Nathan Levien

2017-08-16

The effects of the use of glyphosate (GLY), glyphosate plus carfentrazone (GLY/CAR), and paraquat (PAR) as plant desiccators on the technological and chemical properties of cowpea grains were investigated. All studied desiccants provided lower cooking time to freshly harvested cowpea. However, the coat color of PAR- and GLY/CAR-treated cowpea was reddish in comparison to the control treatment. Principal component analysis (PCA) from liquid chromatography-mass spectrometry (LC-MS) data sets showed a clear distinction among cowpea from the different treatments. Catechin-3-glucoside and epicatechin significantly contributed for discriminating GLY-treated cowpea, while citric acid was responsible for discriminating GLY/CAR-treated cowpea. Quercetin derivative and gluconic acid were responsible for discriminating control treatment. Residual glyphosate and paraquat content was higher than the maximum limits allowed by Codex Alimentarius and the European Union Commission. Improvements in the technological and chemical properties of cowpea may not be overlapped by the risks that those desiccants exhibit when exceeding the maximum limits of tolerance in food.

Principal components of phenolics to characterize red Vinho Verde grapes: anthocyanins or non-coloured compounds?

PubMed

Dopico-García, M S; Fique, A; Guerra, L; Afonso, J M; Pereira, O; Valentão, P; Andrade, P B; Seabra, R M

2008-06-15

Phenolic profile of 10 different varieties of red "Vinho Verde" grapes (Azal Tinto, Borraçal, Brancelho, Doçal, Espadeiro, Padeiro de Basto, Pedral, Rabo de ovelha, Verdelho and Vinhão), from Minho (Portugal) were studied. Nine Flavonols, four phenolic acids, three flavan-3-ols, one stilben and eight anthocyanins were determined. Malvidin-3-O-glucoside was the most abundant anthocyanin while the main non-coloured compound was much more heterogeneous: catechin, epicatechin, myricetin-3-O-glucoside, quercetin-3-O-glucoside or syringetin-3-O-glucoside. Anthocyanin contents ranged from 42 to 97%. Principal component analysis (PCA) was applied to analyse the date and study the relations between the samples and their phenolic profiles. Anthocyanin profile proved to be a good marker to characterize the varieties even considering different origin and harvest. "Vinhão" grapes showed anthocyanins levels until twenty four times higher than the rest of the samples, with 97% of these compounds.

Incorporation of strawberries preparation in yoghurt: impact on phytochemicals and milk proteins.

PubMed

Oliveira, Ana; Alexandre, Elisabete M C; Coelho, Marta; Lopes, Cláudia; Almeida, Domingos P F; Pintado, Manuela

2015-03-15

An immediate decrease in the total antioxidant activity (23%) and total phenolic content (14%) was observed after addition of strawberry preparations to yoghurt. The total anthocyanin content did not change immediately, but decreased 24% throughout the yoghurt shelf-life. The individual compounds, (+)-catechin (60%), (-)-epicatechin (60%), kaempferol (33%) and quercetin-3-rutinoside (29%) decreased after 24h in the yoghurt made with the strawberry preparation. During the remaining period of storage these compounds increased by 47%, 6%, 4% and 18%, respectively. Pelargonidin-3-glucoside decreased 49% after 28 d. Immediately after the addition of the strawberry preparation to yoghurt, β-lactoglobulin decreased to values lower than the limit of detection and α-lactalbumin by approximately 34%, and was reduced further slowly throughout yoghurt self-life. An immediate interaction between the carrageenan present in the strawberry preparation and β-LG was observed. The variations of both polyphenols and protein in the presence of carrageenan and the potential interactions were discussed. Copyright © 2014. Published by Elsevier Ltd.

Stability of bioactive compounds in butiá (Butia odorata) fruit pulp and nectar.

PubMed

Hoffmann, Jessica Fernanda; Zandoná, Giovana Paula; Dos Santos, Priscila Silveira; Dallmann, Camila Müller; Madruga, Francine Bonemann; Rombaldi, Cesar Valmor; Chaves, Fábio Clasen

2017-12-15

Butia odorata is a palm tree native to southern Brazil whose fruit (known as butiá) and leaves are used to make many food products and crafts. Butiá contain several biologically active compounds with potential health benefits. However, processing conditions can alter quality attributes including bioactive compound content. This study evaluated the stability of bioactive compounds in butiá pulp upon pasteurization, during 12months of frozen storage, and in butiá nectar after a 3-month storage period. Pulp pasteurization resulted in a reduction in phenolic, flavonoid, carotenoid, and ascorbic acid contents. After a 12-month frozen storage period, flavonoid, phenolic, and ascorbic acid contents decreased while carotenoid content remained unaltered. Carotenoid, ascorbic acid, and phenolic contents were unaffected by the 3-month storage of butiá nectar; however, flavonoid content and antioxidant potential were reduced. Despite bioactive compound degradation upon heat treatment and storage, butiá nectar remained rich in phenolics, especially (-)-epicatechin, rutin, and (+)-catechin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antimicrobial activity and phytochemical characterization of Carya illinoensis.

PubMed

Bottari, Nathieli Bianchin; Lopes, Leonardo Quintana Soares; Pizzuti, Kauana; Filippi Dos Santos Alves, Camilla; Corrêa, Marcos Saldanha; Bolzan, Leandro Perger; Zago, Adriana; de Almeida Vaucher, Rodrigo; Boligon, Aline Augusti; Giongo, Janice Luehring; Baldissera, Matheus Dellaméa; Santos, Roberto Christ Vianna

2017-03-01

Carya illinoensis is a widespread species, belonging to the Juglandaceae family, commonly known as Pecan. Popularly, the leaves have been used in the treatment of smoking as a hypoglycemic, cleansing, astringent, keratolytic, antioxidant, and antimicrobial agent. The following research aimed to identify for the first time the phytochemical compounds present in the leaves of C. illinoensis and carry out the determination of antimicrobial activity of aqueous and ethanolic extracts. The antimicrobial activity was tested against 20 microorganisms by determining the minimum inhibitory concentration (MIC). Phenolic acids (gallic acid and ellagic acid), flavonoids (rutin), and tannins (catechins and epicatechins) were identified by HPLC-DAD and may be partially responsible for the antimicrobial activity against Gram-positive, Gram-negative, and yeast. The results showed MIC values between 25 mg/mL and 0.78 mg/mL. The extracts were also able to inhibit the production of germ tubes by Candida albicans. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simple solution for a complex problem: proanthocyanidins, galloyl glucoses and ellagitannins fit on a single calibration curve in high performance-gel permeation chromatography.

PubMed

Stringano, Elisabetta; Gea, An; Salminen, Juha-Pekka; Mueller-Harvey, Irene

2011-10-28

This study was undertaken to explore gel permeation chromatography (GPC) for estimating molecular weights of proanthocyanidin fractions isolated from sainfoin (Onobrychis viciifolia). The results were compared with data obtained by thiolytic degradation of the same fractions. Polystyrene, polyethylene glycol and polymethyl methacrylate standards were not suitable for estimating the molecular weights of underivatized proanthocyanidins. Therefore, a novel HPLC-GPC method was developed based on two serially connected PolarGel-L columns using DMF that contained 5% water, 1% acetic acid and 0.15 M LiBr at 0.7 ml/min and 50 °C. This yielded a single calibration curve for galloyl glucoses (trigalloyl glucose, pentagalloyl glucose), ellagitannins (pedunculagin, vescalagin, punicalagin, oenothein B, gemin A), proanthocyanidins (procyanidin B2, cinnamtannin B1), and several other polyphenols (catechin, epicatechin gallate, epicallocatechin gallate, amentoflavone). These GPC predicted molecular weights represented a considerable advance over previously reported HPLC-GPC methods for underivatized proanthocyanidins. Copyright © 2011 Elsevier B.V. All rights reserved.

Dimeric procyanidins: screening for B1 to B8 and semisynthetic preparation of B3, B4, B6, And B8 from a polymeric procyanidin fraction of white willow bark (Salix alba).

PubMed

Esatbeyoglu, Tuba; Wray, Victor; Winterhalter, Peter

2010-07-14

Fifty-seven samples have been analyzed with regard to the occurrence of dimeric procyanidins B1-B8 as well as the composition of polymeric procyanidins. Fifty-two samples were found to contain polymeric procyanidins. In most of the samples, (-)-epicatechin was the predominant unit present. In white willow bark (Salix alba), however, large amounts of (+)-catechin (81.0%) were determined by means of phloroglucinolysis. White willow bark has therefore been used for the semisynthetic formation of dimeric procyanidins B3 [(+)-C-4alpha --> 8-(+)-C)], B4 [(+)-C-4alpha --> 8-(-)-EC)], B6 [(+)-C-4alpha --> 6-(+)-C)], and B8 [(+)-C-4alpha --> 6-(-)-EC)]. The reaction mixtures of the semisynthesis were successfully fractionated with high-speed countercurrent chromatography (HSCCC), and dimeric procyanidins B3, B4, B6, and B8 were obtained on a preparative scale.

Physicochemical properties and antioxidant capacity of raw, roasted and puffed cacao beans.

PubMed

Hu, SuJung; Kim, Byung-Yong; Baik, Moo-Yeol

2016-03-01

The antioxidant capacity and attributable bioactive compounds of puffed cacao beans were investigated. Roasting was carried out at 190°C for 15min and puffing was performed at 4-7kgf/cm(2). Cacao beans puffed at 4kgf/cm(2) showed the highest total polyphenols (23.16mgGAE/gsample) and total flavonoids (10.65mgCE/gsample) (p<0.05). As the puffing pressure increased, the amount of total polyphenols and total flavonoids decreased. The antioxidant capacity of cacao beans reflected the total polyphenols and flavonoids measured. The quantities of theobromine, catechin, epicatechin, and procyanidin B2 were higher in cacao beans puffed at 4kgf/cm(2) than in roasted cacao beans. Puffed cacao beans received a good sensory score in flavor, but sourness increased as puffing pressure increased. Thus, these results suggest that, in cacao bean processing, puffing could be an alternative to roasting, which provide a rich taste and high antioxidant capacity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Active compounds, antioxidant activity and α-glucosidase inhibitory activity of different varieties of Chaenomeles fruits.

PubMed

Miao, Jing; Li, Xia; Zhao, Chengcheng; Gao, Xiaoxiao; Wang, Ying; Gao, Wenyuan

2018-05-15

Chaenomeles is an important source for food industry in China, and its planting area is expanding year by year. This study was conducted to evaluate different varieties of Chaenomeles by comparing the chemical compositions, antioxidant activity and α-glucosidase inhibitory activity of peels and fleshes from twelve varieties of Chaenomeles. In the results, peels of Chaenomeles contain more phenolics, flavonoids and triterpenes, and show better antioxidant activity and α-glucosidase inhibitory activity than their fleshes. All varieties of Chaenomeles perform different depend on cultivar and climatic conditions. Oleanolic acid, ursolic acid, protocatechuic acid, rutin, catechin, caffeic acid, syringic acid, epicatechin, hyperin, quercetin, kaempferol and chlorogenic acid are main active compounds in Chaenomeles. Zheng'an, Liufu, Zimugua1, Qijiang and Changjun get Top five scores. This is the first study on the peels and fleshes of twelve varieties of Chaenomeles, and it gives insights into variety selection in the planting and production of Chaenomeles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Separation of Active Compounds from Food by-Product (Cocoa Shell) Using Subcritical Water Extraction.

PubMed

Jokić, Stela; Gagić, Tanja; Knez, Željko; Šubarić, Drago; Škerget, Mojca

2018-06-11

Large amounts of residues are produced in the food industries. The waste shells from cocoa processing are usually burnt for fuel or used as a mulch in gardens to add nutrients to soil and to suppress weeds. The objectives of this work were: (a) to separate valuable compounds from cocoa shell by applying sustainable green separation process—subcritical water extraction (SWE); (b) identification and quantification of active compounds, sugars and sugar degradation products in obtained extracts using HPLC; (c) characterization of the antioxidant activity of extracts; (d) optimization of separation process using response surface methodology (RSM). Depending on applied extraction conditions, different concentration of theobromine, caffeine, theophylline, epicatechin, catechin, chlorogenic acid and gallic acid were determined in the extracts obtained by subcritical water. Furthermore, mannose, glucose, xylose, arabinose, rhamnose and fucose were detected as well as their important degradation products such as 5-hydroxymethylfurfural (5-HMF), furfural, levulinic acid, lactic acid and formic acid.

Bactericidal activity of glutaraldehyde-like compounds from olive products.

PubMed

Medina, Eduardo; Brenes, Manuel; García, Aranzazu; Romero, Concepción; de Castro, Antonio

2009-12-01

The bactericidal effects of several olive compounds (nonenal, oleuropein, tyrosol, the dialdehydic form of decarboxymethyl elenolic acid either free [EDA] or linked to tyrosol [TyEDA] or to hydroxytyrosol [HyEDA]), other food phenolic compounds (catechin, epicatechin, eugenol, thymol, carvacrol, and carnosic acid), and commercial disinfectants (glutaraldehyde [GTA] and ortho-phthalaldehyde [OPA]), were tested against strains of Pseudomonas fluorescens, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. It was found that the bactericidal activities of olive GTA-like compounds (EDA, HyEDA, and TyEDA) were greater than those exerted by several food phenolic substances. Surprisingly, these olive antimicrobials were as active as the synthetic biocides GTA and OPA against the four bacteria studied. Thus, it has been proposed that the bactericidal activity of the main olive antimicrobials is primarily due to their dialdehydic structure, which is similar to that of the commercial biocides GTA and OPA. Our results clearly reveal that olive GTA-like compounds possess a strong bactericidal activity even greater than that of other food phenolic compounds or synthetic biocides.

Bioactive compounds and antioxidant activity in scalded Jalapeño pepper industrial byproduct (Capsicum annuum).

PubMed

Sandoval-Castro, Claudia Jaqueline; Valdez-Morales, Maribel; Oomah, B Dave; Gutiérrez-Dorado, Roberto; Medina-Godoy, Sergio; Espinosa-Alonso, L Gabriela

2017-06-01

Bioactive compounds and antioxidant activity were evaluated from industrial Jalapeño pepper byproducts and simulated non processed byproducts from two Mexican states (Chihuahua and Sinaloa) to determine their value added potential as commercial food ingredients. Aqueous 80% ethanol produced about 13% of dry extract of polar compounds. Total phenolic content increased and capsaicin and dihydrocapsaicin decreased on scalding samples (80 °C, 2 min) without affecting ascorbic acid. The major phenolic compounds, rutin, epicatechin and catechin comprised 90% of the total compounds detected by HPLC of each Jalapeño pepper byproducts. ORAC analysis showed that the origin and scalding process affected the antioxidant activity which correlated strongly with capsaicin content. Although scalding decreased capsaicinoids (up to 42%), phenolic content by (up to 16%), and the antioxidant activity (variable). Jalapeño pepper byproduct is a good source of compounds with antioxidant activity, and still an attractive ingredient to develop useful innovative products with potential food/non-food applications simultaneously reducing food loss and waste.

Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption.

PubMed

Peng, Xiaofang; Ma, Jinyu; Chao, Jianfei; Sun, Zheng; Chang, Raymond Chuen-Chung; Tse, Iris; Li, Edmund T S; Chen, Feng; Wang, Mingfu

2010-06-09

Advanced glycation endproducts (AGEs) are a group of complex and heterogeneous compounds formed from nonenzymatic reactions. The accumulation of AGEs in vivo has been implicated as a major pathogenic process in diabetic complications and other health disorders, such as atherosclerosis and Alzheimer's disease, and normal aging. In this study, we investigate the inhibitory effects of cinnamon bark proanthocyanidins, catechin, epicatechin, and procyanidin B2 on the formation of specific AGE representatives including pentosidine, N(epsilon)-(carboxymethyl)lysine (CML), and methylglyoxal (MGO) derived AGEs. These compounds displayed obvious inhibitory effects on these specific AGEs, which are largely attributed to both their antioxidant activities and carbonyl scavenging capacities. Meanwhile, in terms of their potent MGO scavenging capacities, effects of these proanthocyanidins on insulin signaling pathways interfered by MGO were evaluated in 3T3-L1 adipocytes. According to the results, proanthocyanidins exerted protective effects on glucose consumption impaired by MGO in 3T3-L1 fat cells.

Bioavailability and activity of phytosome complexes from botanical polyphenols: the silymarin, curcumin, green tea, and grape seed extracts.

PubMed

Kidd, Parris M

2009-09-01

Plant-derived polyphenols are increasingly receiving attention as dietary supplements for the homeostatic management of inflammation, to support detoxication, and for anticancer, weight loss, and other benefits. Their pro-homeostatic effects on genes, transcription factors, enzymes, and cell signaling pathways are being intensively explored, but the poor bioavailability of some polyphenols likely contributes to poor clinical trial outcomes. This review covers four polyphenol preparations with poor bioavailability and their complexation into phytosomes to bypass this problem. Silybin and the other silymarin flavonolignans from milk thistle conserve tissue glutathione, are liver-protective, and have anticancer potential. Curcumin and its related diphenolic curcuminoids have potent antioxidant, anti-inflammatory, and anti-carcinogenic properties. The green tea flavan-3-ol catechins have antioxidant, anti-inflammatory, cardio- and neuro-protective effects, and anti-carcinogenic benefits, with fat oxidation effects coupled to weight loss. The complex grape seed proanthocyanidin mix (including catechin and epicatechin monomers and oligomers) counters oxidative stress and protects the circulatory system. For each of these preparations, conversion into phytosomes has improved efficacy without compromising safety. The phytosome technology creates intermolecular bonding between individual polyphenol molecules and one or more molecules of the phospholipid, phosphatidylcholine (PC). Molecular imaging suggests that PC molecule(s) enwrap each polyphenol; upon oral intake the amphipathic PC molecules likely usher the polyphenol through the intestinal epithelial cell outer membrane, subsequently accessing the bloodstream. PC itself has proven clinical efficacy that contributes to phytosome in vivo actions. As a molecular delivery vehicle, phytosome technology substantially improves the clinical applicabilities of polyphenols and other poorly absorbed plant medicinals.

Proanthocyanidin synthesis in Theobroma cacao: genes encoding anthocyanidin synthase, anthocyanidin reductase, and leucoanthocyanidin reductase

PubMed Central

2013-01-01

Background The proanthocyanidins (PAs), a subgroup of flavonoids, accumulate to levels of approximately 10% total dry weight of cacao seeds. PAs have been associated with human health benefits and also play important roles in pest and disease defense throughout the plant. Results To dissect the genetic basis of PA biosynthetic pathway in cacao (Theobroma cacao), we have isolated three genes encoding key PA synthesis enzymes, anthocyanidin synthase (ANS), anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR). We measured the expression levels of TcANR, TcANS and TcLAR and PA content in cacao leaves, flowers, pod exocarp and seeds. In all tissues examined, all three genes were abundantly expressed and well correlated with PA accumulation levels, suggesting their active roles in PA synthesis. Overexpression of TcANR in an Arabidopsis ban mutant complemented the PA deficient phenotype in seeds and resulted in reduced anthocyanidin levels in hypocotyls. Overexpression of TcANS in tobacco resulted in increased content of both anthocyanidins and PAs in flower petals. Overexpression of TcANS in an Arabidopsis ldox mutant complemented its PA deficient phenotype in seeds. Recombinant TcLAR protein converted leucoanthocyanidin to catechin in vitro. Transgenic tobacco overexpressing TcLAR had decreased amounts of anthocyanidins and increased PAs. Overexpressing TcLAR in Arabidopsis ldox mutant also resulted in elevated synthesis of not only catechin but also epicatechin. Conclusion Our results confirm the in vivo function of cacao ANS and ANR predicted based on sequence homology to previously characterized enzymes from other species. In addition, our results provide a clear functional analysis of a LAR gene in vivo. PMID:24308601

Proanthocyanidin synthesis in Theobroma cacao: genes encoding anthocyanidin synthase, anthocyanidin reductase, and leucoanthocyanidin reductase.

PubMed

Liu, Yi; Shi, Zi; Maximova, Siela; Payne, Mark J; Guiltinan, Mark J

2013-12-05

The proanthocyanidins (PAs), a subgroup of flavonoids, accumulate to levels of approximately 10% total dry weight of cacao seeds. PAs have been associated with human health benefits and also play important roles in pest and disease defense throughout the plant. To dissect the genetic basis of PA biosynthetic pathway in cacao (Theobroma cacao), we have isolated three genes encoding key PA synthesis enzymes, anthocyanidin synthase (ANS), anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR). We measured the expression levels of TcANR, TcANS and TcLAR and PA content in cacao leaves, flowers, pod exocarp and seeds. In all tissues examined, all three genes were abundantly expressed and well correlated with PA accumulation levels, suggesting their active roles in PA synthesis. Overexpression of TcANR in an Arabidopsis ban mutant complemented the PA deficient phenotype in seeds and resulted in reduced anthocyanidin levels in hypocotyls. Overexpression of TcANS in tobacco resulted in increased content of both anthocyanidins and PAs in flower petals. Overexpression of TcANS in an Arabidopsis ldox mutant complemented its PA deficient phenotype in seeds. Recombinant TcLAR protein converted leucoanthocyanidin to catechin in vitro. Transgenic tobacco overexpressing TcLAR had decreased amounts of anthocyanidins and increased PAs. Overexpressing TcLAR in Arabidopsis ldox mutant also resulted in elevated synthesis of not only catechin but also epicatechin. Our results confirm the in vivo function of cacao ANS and ANR predicted based on sequence homology to previously characterized enzymes from other species. In addition, our results provide a clear functional analysis of a LAR gene in vivo.

Green tea extract supplementation induces the lipolytic pathway, attenuates obesity, and reduces low-grade inflammation in mice fed a high-fat diet.

PubMed

Cunha, Cláudio A; Lira, Fábio S; Rosa Neto, José C; Pimentel, Gustavo D; Souza, Gabriel I H; da Silva, Camila Morais Gonçalves; de Souza, Cláudio T; Ribeiro, Eliane B; Sawaya, Alexandra Christine Helena Frankland; Oller do Nascimento, Cláudia M; Rodrigues, Bruno; de Oliveira Carvalho, Patrícia; Oyama, Lila M

2013-01-01

The aim of this study was to evaluate the effects of green tea Camellia sinensis extract on proinflammatory molecules and lipolytic protein levels in adipose tissue of diet-induced obese mice. Animals were randomized into four groups: CW (chow diet and water); CG (chow diet and water + green tea extract); HW (high-fat diet and water); HG (high-fat diet and water + green tea extract). The mice were fed ad libitum with chow or high-fat diet and concomitantly supplemented (oral gavage) with 400 mg/kg body weight/day of green tea extract (CG and HG, resp.). The treatments were performed for eight weeks. UPLC showed that in 10 mg/mL green tea extract, there were 15 μg/mg epigallocatechin, 95 μg/mg epigallocatechin gallate, 20.8 μg/mg epicatechin gallate, and 4.9 μg/mg gallocatechin gallate. Green tea administered concomitantly with a high-fat diet increased HSL, ABHD5, and perilipin in mesenteric adipose tissue, and this was associated with reduced body weight and adipose tissue gain. Further, we observed that green tea supplementation reduced inflammatory cytokine TNFα levels, as well as TLR4, MYD88, and TRAF6 proinflammatory signalling. Our results show that green tea increases the lipolytic pathway and reduces adipose tissue, and this may explain the attenuation of low-grade inflammation in obese mice.

Antioxidant activity and phenolic profile of pistachio (Pistacia vera L., variety Bronte) seeds and skins.

PubMed

Tomaino, Antonio; Martorana, Maria; Arcoraci, Teresita; Monteleone, Domenico; Giovinazzo, Corrado; Saija, Antonella

2010-09-01

Pistachio (Pistacia vera L.; Anacardiaceae) is native of aride zones of Central and West Asia and distributed throughout the Mediterranean basin. In Italy, a pistachio cultivar of high quality is typical of Bronte (Sicily), an area around the Etna volcano, where the lava land and climate allow the production of a nut with intense green colour and aromatic taste, very appreciated in international markets. Pistachio nuts are a rich source of phenolic compounds, and have recently been ranked among the first 50 food products highest in antioxidant potential. Pistachio nuts are often used after removing the skin, which thus represents a significant by-product of pistachio industrial processing. The present study was carried out to better characterize the phenolic composition and the antioxidant activity of Bronte pistachios, with the particular aim to evaluate the differences between pistachio seeds and skins. The total content of phenolic compounds in pistachios was shown to be significantly higher in skins than in seeds. By HPLC analysis, gallic acid, catechin, eriodictyol-7-O-glucoside, naringenin-7-O-neohesperidoside, quercetin-3-O-rutinoside and eriodictyol were found both in pistachio seeds than in skins; furthermore, genistein-7-O-glucoside, genistein, daidzein and apigenin appeared to be present only in pistachio seeds, while epicatechin, quercetin, naringenin, luteolin, kaempferol, cyanidin-3-O-galactoside and cyanidin-3-O-glucoside are contained only in pistachio skins. The antioxidant activity of pistachio seeds and skins were determined by means of four different assays (DPPH assay, Folin-Ciocalteau colorimetric method and TEAC assay, SOD-mimetic assay). As expected on the basis of the chemical analyses, pistachio skins have shown to possess a better activity with respect to seeds in all tests. The excellent antioxidant activity of pistachio skins can be explained by its higher content of antioxidant phenolic compounds. By HPLC-TLC analysis, gallic acid, catechin, cyanidin-3-O-galactoside, eriodictyol-7-O-glucoside and epicatechin appeared to be responsible for the antioxidant activity of pistachio skin, together with other unidentified compounds. In conclusion, our work has contributed to clarify some particular characteristics of Bronte pistachios and the specific antioxidant power of pistachio skins. Introduction of pistachios in daily diet may be of undoubted utility to protect human health and well-being against cancer, inflammatory diseases, cardiovascular pathologies and, more generally, pathological conditions related to free radical overproduction. On the other hand, pistachio skins could be successfully employed in food, cosmetic and pharmaceutical industry. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Human O-sulfated metabolites of (-)-epicatechin and methyl-(-)-epicatechin are poor substrates for commercial aryl-sulfatases: implications for studies concerned with quantifying epicatechin bioavailability.

PubMed

Saha, S; Hollands, W; Needs, P W; Ostertag, L M; de Roos, B; Duthie, G G; Kroon, P A

2012-06-01

Epicatechin is a widely consumed dietary flavonoid and there is substantial evidence that it contributes to the health benefits reported for flavanol-rich cocoa products including dark chocolate. Numerous reports have described the appearance of epicatechin and epicatechin phase-2 conjugates (sulfates and glucuronides of epicatechin and methylepicatechin) in blood and urine samples of subjects following ingestion of epicatechin. The most widely reported method of quantifying total epicatechin in plasma and urine samples involves hydrolysis with a mixture of β-glucuronidase and sulfatase to convert the conjugates to epicatechin aglycone which is subsequently quantified. We observed a lack of hydrolysis of epicatechin sulfates and methylepicatechin sulfates using commercial sulfatases and investigated this further. Samples of urine or plasma from subjects who had consumed epicatechin were subjected to enzyme hydrolysis and then analysed using LC-MS/MS, or analysed without enzyme hydrolysis. Attempts to increase the extent of hydrolysis of epicatechin conjugates were made by increasing the amount of enzyme, hydrolysis pH and length of incubations, and using alternative sources of enzyme. The standard hydrolysis conditions failed to hydrolyse the majority of epicatechin sulfates and methylepicatechin sulfates. Even when the quantity of enzyme and incubation period was increased, the pH optimised, or alternative sources of sulfatases were used, epicatechin monosulfates and methylepicatechin monosulfates remained as major peaks in the chromatograms of the samples. An assessment of literature data strongly suggested that the majority of reports where enzyme hydrolysis was used had significantly underestimated epicatechin bioavailability in humans. Methods for quantifying epicatechin concentrations in blood and urine need to take account of the lack of hydrolysis of (methyl)epicatechin-sulfates, for example by quantifying these directly using LC-MS/MS. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dark chocolate receptors: epicatechin-induced cardiac protection is dependent on delta-opioid receptor stimulation.

PubMed

Panneerselvam, Mathivadhani; Tsutsumi, Yasuo M; Bonds, Jacqueline A; Horikawa, Yousuke T; Saldana, Michelle; Dalton, Nancy D; Head, Brian P; Patel, Piyush M; Roth, David M; Patel, Hemal H

2010-11-01

Epicatechin, a flavonoid, is a well-known antioxidant linked to a variety of protective effects in both humans and animals. In particular, its role in protection against cardiovascular disease has been demonstrated by epidemiologic studies. Low-dose epicatechin, which does not have significant antioxidant activity, is also protective; however, the mechanism by which low-dose epicatechin induces this effect is unknown. Our laboratory tested the hypothesis that low-dose epicatechin mediates cardiac protection via opioid receptor activation. C57BL/6 mice were randomly assigned to 1 of 10 groups: control, epicatechin, naloxone (nonselective opioid receptor antagonist), epicatechin + naloxone, naltrindole (δ-specific opioid receptor antagonist), epicatechin + naltrindole, norbinaltorphimine (nor-BNI, κ-specific opioid receptor antagonist), epicatechin + nor-BNI, 5-hydroxydecanoic acid [5-HD, ATP-sensitive potassium channel antagonist], and epicatechin + 5-HD. Epicatechin (1 mg/kg) or other inhibitors (5 mg/kg) were administered by oral gavage or intraperitoneal injection, respectively, daily for 10 days. Mice were subjected to 30 min coronary artery occlusion followed by 2 h of reperfusion, and infarct size was determined via planimetry. Whole heart homogenates were assayed for downstream opioid receptor signaling targets. Infarct size was significantly reduced in epicatechin- and epicatechin + nor-BNI-treated mice compared with control mice. This protection was blocked by naloxone, naltrindole, and 5-HD. Epicatechin and epicatechin + nor-BNI increased the phosphorylation of Src, Akt, and IκBα, while simultaneously decreasing the expression of c-Jun NH(2)-terminal kinase and caspase-activated DNase. All signaling effects are consistent with opioid receptor stimulation and subsequent cardiac protection. Naloxone, naltrindole, and 5-HD attenuated these effects. In conclusion, epicatechin acts via opioid receptors and more specifically through the δ-opioid receptor to produce cardiac protection from ischemia-reperfusion injury.

Effect of consuming a grape seed supplement with abundant phenolic compounds on the oxidative status of healthy human volunteers.

PubMed

Grases, Felix; Prieto, Rafel M; Fernández-Cabot, Rafel A; Costa-Bauzá, Antonia; Sánchez, Ana M; Prodanov, Marin

2015-09-09

Diverse enzymatic and non-enzymatic antioxidants provide protection against reactive oxygen species in humans and other organisms. The nonenzymatic antioxidants include low molecular mass molecules such as plant-derived phenols. This study identified the major phenolic compounds of a grape seed extract by HPLC and analyzed the effect of consumption of biscuits enriched with this extract on the urinary oxidative status of healthy subjects by measurement of urine redox potential. The major phenolic compounds were characterized in a red grape seed extract separated by HPLC with detection by a photodiode array (PDA), fluorescence (FL) and quadrupole mass spectrometer (MS). A nutritional study in a healthy volunteers group was done. Each volunteer ate eight traditional biscuits with no red grape seed extract supplementation. The second day each volunteer ate eight traditional biscuits supplemented with 0.6% (wt/wt) of grape seed extract. An overnight urine sample was obtained for each treatment. The redox potential was measured at 25 °C using a potentiometer in each urine sample. Epicatechin, catechin, procyanidin dimers B1 to B4, and the procyanidin trimer C2 were the major phenolic components in the extract. Epicatechin gallate and procyanidin dimers B1-3-G and B2-3'-G were the major galloylated flavan-3-ols. The forty-six healthy volunteers each shown a reduction of the urine redox potential after the treatment by traditional biscuits supplemented with the grape seed extract. This simple dietary intervention significantly reduced (33%) the urine redox potential, reflecting an overall increase in antioxidant status. Incorporation of plant-derived phenols in the diet may increase anti-oxidative status.

Tea enhances insulin activity.

PubMed

Anderson, Richard A; Polansky, Marilyn M

2002-11-20

The most widely known health benefits of tea relate to the polyphenols as the principal active ingredients in protection against oxidative damage and in antibacterial, antiviral, anticarcinogenic, and antimutagenic activities, but polyphenols in tea may also increase insulin activity. The objective of this study was to determine the insulin-enhancing properties of tea and its components. Tea, as normally consumed, was shown to increase insulin activity >15-fold in vitro in an epididymal fat cell assay. Black, green, and oolong teas but not herbal teas, which are not teas in the traditional sense because they do not contain leaves of Camellia senensis, were all shown to increase insulin activity. High-performance liquid chromatography fractionation of tea extracts utilizing a Waters SymmetryPrep C18 column showed that the majority of the insulin-potentiating activity for green and oolong teas was due to epigallocatechin gallate. For black tea, the activity was present in several regions of the chromatogram corresponding to, in addition to epigallocatechin gallate, tannins, theaflavins, and other undefined compounds. Several known compounds found in tea were shown to enhance insulin with the greatest activity due to epigallocatechin gallate followed by epicatechin gallate, tannins, and theaflavins. Caffeine, catechin, and epicatechin displayed insignificant insulin-enhancing activities. Addition of lemon to the tea did not affect the insulin-potentiating activity. Addition of 5 g of 2% milk per cup decreased the insulin-potentiating activity one-third, and addition of 50 g of milk per cup decreased the insulin-potentiating activity approximately 90%. Nondairy creamers and soy milk also decreased the insulin-enhancing activity. These data demonstrate that tea contains in vitro insulin-enhancing activity and the predominant active ingredient is epigallocatechin gallate.

Does epicatechin contribute to the acute vascular function effects of dark chocolate? A randomized, crossover study.

PubMed

Dower, James I; Geleijnse, Johanna M; Kroon, Paul A; Philo, Mark; Mensink, Marco; Kromhout, Daan; Hollman, Peter C H

2016-11-01

Cocoa, rich in flavan-3-ols, improves vascular function, but the contribution of specific flavan-3-ols is unknown. We compared the effects of pure epicatechin, a major cocoa flavan-3-ol, and chocolate. In a randomized crossover study, twenty healthy men (40-80 years) were supplemented with: (1) 70g dark chocolate (150 mg epicatechin) with placebo capsules; (2) pure epicatechin capsules (2 × 50 mg epicatechin) with 75g white chocolate; and (3) placebo capsules with 75 g white chocolate (0 mg epicatechin). Vascular function (flow-mediated dilation (FMD) and augmentation index (AIx)) were measured before and 2 hours after interventions. Epicatechin metabolites time-profiles were measured in blood to calculate the bioavailability. Pure epicatechin did not significantly improve FMD (+0.75%; p = 0.10) or AIx (-2.2%; p = 0.23) compared to placebo. Dark chocolate significantly improved FMD (+0.96%; p = 0.04) and AIx (-4.6%; p = 0.02). Differences in improvements in FMD (+ 0.21%; p = 0.65) or Aix (-2.4%; p = 0.20) between pure epicatechin and dark chocolate were not significant. The bioavailability of epicatechin did not differ between pure epicatechin and dark chocolate (p = 0.14). Despite differences in epicatechin dose, improvements in vascular function after pure epicatechin and chocolate were similar and the bioavailability did not differ, suggesting a role for epicatechin. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Procyanidins Negatively Affect the Activity of the Phosphatases of Regenerating Liver

PubMed Central

Stadlbauer, Sven; Rios, Pablo; Ohmori, Ken; Suzuki, Keisuke; Köhn, Maja

2015-01-01

Natural polyphenols like oligomeric catechins (procyanidins) derived from green tea and herbal medicines are interesting compounds for pharmaceutical research due to their ability to protect against carcinogenesis in animal models. It is nevertheless still unclear how intracellular pathways are modulated by polyphenols. Monomeric polyphenols were shown to affect the activity of some protein phosphatases (PPs). The three phosphatases of regenerating liver (PRLs) are close relatives and promising therapeutic targets in cancer. In the present study we show that several procyanidins inhibit the activity of all three members of the PRL family in the low micromolar range, whereas monomeric epicatechins show weak inhibitory activity. Increasing the number of catechin units in procyanidins to more than three does not further enhance the potency. Remarkably, the tested procyanidins showed selectivity in vitro when compared to other PPs, and over 10-fold selectivity toward PRL-1 over PRL-2 and PRL-3. As PRL overexpression induces cell migration compared to control cells, the effect of procyanidins on this phenotype was studied. Treatment with procyanidin C2 led to a decrease in cell migration of PRL-1- and PRL-3-overexpressing cells, suggesting the compound-dependent inhibition of PRL-promoted cell migration. Treatment with procyanidin B3 led to selective suppression of PRL-1 overexpressing cells, thereby corroborating the selectivity toward PRL-1- over PRL-3 in vitro. Together, our results show that procyanidins negatively affect PRL activity, suggesting that PRLs could be targets in the polypharmacology of natural polyphenols. Furthermore, they are interesting candidates for the development of PRL-1 inhibitors due to their low cellular toxicity and the selectivity within the PRL family. PMID:26226290

Determination of changes in the metabolic profile of avocado fruits (Persea americana) by two CE-MS approaches (targeted and non-targeted).

PubMed

Contreras-Gutiérrez, Paulina K; Hurtado-Fernández, Elena; Gómez-Romero, María; Ignacio Hormaza, José; Carrasco-Pancorbo, Alegría; Fernández-Gutiérrez, Alberto

2013-10-01

A CZE method with two different MS detection conditions (MRM and Full Scan) was developed to determine qualitative and quantitative changes in the metabolic profile of avocado fruits (Persea americana). LODs in MRM approach were found between 20.1 and 203.0 ppb for abscisic acid and perseitol, respectively, whilst in Full Scan, varied within the range 0.22–1.90 ppm for the same metabolites. The RSDs for reproducibility test did not exceed 11.45%. The two MS approaches were used to quantify 10 metabolites (phenolic acids, flavonoids, a carbohydrate, an organic acid, a vitamin and a phytohormone) in 18 samples of avocado at different ripening states, and the achieved results were compared. Perseitol, quinic, chlorogenic, trans-cinnamic, pantothenic and abscisic acids, as well as epicatechin and catechin decreased during the ripening process, whereas ferulic and p-coumaric acids showed the opposite trend. Moreover, some other unknown compounds whose concentration changed largely during ripening were also studied by MS/MS and QTOF MS to get a tentative identification.

Phenolic composition of pomegranate peel extracts using an liquid chromatography-mass spectrometry approach with silica hydride columns.

PubMed

Young, Joshua E; Pan, Zhongli; Teh, Hui Ean; Menon, Veena; Modereger, Brent; Pesek, Joseph J; Matyska, Maria T; Dao, Lan; Takeoka, Gary

2017-04-01

The peels of different pomegranate cultivars (Molla Nepes, Parfianka, Purple Heart, Wonderful and Vkunsyi) were compared in terms of phenolic composition and total phenolics. Analyses were performed on two silica hydride based stationary phases: phenyl and undecanoic acid columns. Quantitation was accomplished by developing a liquid chromatography with mass spectrometry approach for separating different phenolic analytes, initially in the form of reference standards and then with pomegranate extracts. The high-performance liquid chromatography columns used in the separations had the ability to retain a wide polarity range of phenolic analytes, as well as offering beneficial secondary selectivity mechanisms for resolving the isobaric compounds, catechin and epicatechin. The Vkunsyi peel extract had the highest concentration of phenolics (as determined by liquid chromatography with mass spectrometry) and was the only cultivar to contain the important compound punicalagin. The liquid chromatography with mass spectrometry data were compared to the standard total phenolics content as determined by using the Folin-Ciocalteu assay. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Red wine tannins fluidify and precipitate lipid liposomes and bicelles. A role for lipids in wine tasting?

PubMed

Furlan, Aurélien L; Castets, Aurore; Nallet, Frédéric; Pianet, Isabelle; Grélard, Axelle; Dufourc, Erick J; Géan, Julie

2014-05-20

Sensory properties of red wine tannins are bound to complex interactions between saliva proteins, membranes taste receptors of the oral cavity, and lipids or proteins from the human diet. Whereas astringency has been widely studied in terms of tannin-saliva protein colloidal complexes, little is known about interactions between tannins and lipids and their implications in the taste of wine. This study deals with tannin-lipid interactions, by mimicking both oral cavity membranes by micrometric size liposomes and lipid droplets in food by nanometric isotropic bicelles. Deuterium and phosphorus solid-state NMR demonstrated the membrane hydrophobic core disordering promoted by catechin (C), epicatechin (EC), and epigallocatechin gallate (EGCG), the latter appearing more efficient. C and EGCG destabilize isotropic bicelles and convert them into an inverted hexagonal phase. Tannins are shown to be located at the membrane interface and stabilize the lamellar phases. These newly found properties point out the importance of lipids in the complex interactions that happen in the mouth during organoleptic feeling when ingesting tannins.

Phenolic compounds, organic acids and antioxidant activity of grape juices produced from new Brazilian varieties planted in the Northeast Region of Brazil.

PubMed

Lima, Marcos Dos Santos; Silani, Igor de Souza Veras; Toaldo, Isabela Maia; Corrêa, Luiz Claudio; Biasoto, Aline Camarão Telles; Pereira, Giuliano Elias; Bordignon-Luiz, Marilde T; Ninow, Jorge Luiz

2014-10-15

The phenolic compounds, organic acids and the antioxidant activity were determined for grape juice samples from new Brazilian varieties grown in the Sub-middle São Francisco Valley in the Northeast Region of Brazil. The results showed that the Brazilian grape juices have high antioxidant activity, which was significantly correlated with the phenolic compounds catechin, epicatechin gallate, procyanidin B1, rutin, gallic acid, caffeic acid, p-coumaric acid, pelargonidin-3-glucoside, cyanidin-3-glucoside, cyaniding-3,5-diglucoside and delphinidin-3-glucoside. The produced juice samples showed higher concentrations of trans-resveratrol than those observed in juices made from different varieties of grapes from traditional growing regions. Organic acids concentrations were similar to those of juices produced from other classical varieties. It was demonstrated that it is possible to prepare juices from grapes of new varieties grown in the Northeast of Brazil containing a high content of bioactive compounds and typical characteristics of the tropical viticulture practised in the Sub-middle São Francisco Valley. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Non-targeted Approach to Chemical Discrimination Between Green Tea Dietary Supplements and Green Tea Leaves by HPLC/MS

PubMed Central

Sun, Jianghao; Chen, Pei; Lin, Long-Ze; Harnly, James M.

2013-01-01

Green tea-based dietary supplements (GTDSs) have gained popularity in the U.S. market in recent years. This study evaluated the phytochemical composition difference of GTDS in comparison with green tea leaves using an HPLC/MS fingerprinting technique coupled with chemometric analysis. Five components that are most responsible for class separation among samples were identified as (−) epicatechin gallate, strictinin, trigalloylglucose, quercetin-3-O-glucosylrhamnosylglucoside, and kaempferol-3-O-galactosyl-rhamnosylglucoside, according to the accurate mass measurements and MS/MS data. The similarity coefficients between the GTDSs in solid form with green tea were 0.55 to 0.91, while for the GTDSs in liquid form they were 0.12 to 0.89, which suggested that chemical composition variance across the GTDSs was significant. Flavonol aglycone concentrations were higher in GTDSs than in tea leaves, indicating the degradation of flavonol glycosides or the oxidation of catechin during the manufacturing and storage processes. In some GTDS samples, compounds were identified that were on the label. The results demonstrate the urgency of QC for GTDS products. PMID:21563682

Black soybean seed coat polyphenols prevent AAPH-induced oxidative DNA-damage in HepG2 cells

PubMed Central

Yoshioka, Yasukiyo; Li, Xiu; Zhang, Tianshun; Mitani, Takakazu; Yasuda, Michiko; Nanba, Fumio; Toda, Toshiya; Yamashita, Yoko; Ashida, Hitoshi

2017-01-01

Black soybean seed coat extract (BE), which contains abundant polyphenols such as procyanidins, cyanidin 3-glucoside, (+)-catechin, and (−)­epicatechin, has been reported on health beneficial functions such as antioxidant activity, anti-inflammatory, anti-obesity, and anti-diabetic activities. In this study, we investigated that prevention of BE and its polyphenols on 2,2'-azobis(2-methylpropionamide) dihydrochloride (AAPH)-induced oxidative DNA damage, and found that these polyphenols inhibited AAPH-induced formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker for oxidative DNA damage in HepG2 cells. Under the same conditions, these polyphenols also inhibited AAPH-induced accumulation of reactive oxygen species (ROS) in the cells. Inhibition of ROS accumulation was observed in both cytosol and nucleus. It was confirmed that these polyphenols inhibited formation of AAPH radical using oxygen radical absorbance capacity assay under the cell-free conditions. These results indicate that polyphenols in BE inhibit free radical-induced oxidative DNA damages by their potent antioxidant activity. Thus, BE is an effective food material for prevention of oxidative stress and oxidative DNA damages. PMID:28366989

Almond (Prunus dulcis (Mill.) D.A. Webb) polyphenols: from chemical characterization to targeted analysis of phenolic metabolites in humans.

PubMed

Bartolomé, Begoña; Monagas, María; Garrido, Ignacio; Gómez-Cordovés, Carmen; Martín-Alvarez, Pedro J; Lebrón-Aguilar, Rosa; Urpí-Sardà, Mireia; Llorach, Rafael; Andrés-Lacueva, Cristina

2010-09-01

In this paper, a survey of our studies on almond polyphenols including their chemical characterization and further bioavailability in humans is reported. Combination of analytical techniques (LC-DAD/fluorescence, LC/ESI-MS and MALDI-TOF-MS) allowed us, for the first time, the identification of A- and B-type procyanidin, propelargonidin and prodelphinidin polymers in almond skins. Glucuronide, O-methyl glucuronide, sulfate and O-methyl sulfate derivatives of (epi)catechin, as well as the glucuronide conjugates of naringenin and isorhamnetin, and sulfate conjugates of isorhamnetin, together with conjugates of hydroxyphenylvalerolactones were detected in plasma and urine samples after the intake of almond skin polyphenols. In addition, numerous microbial-derived metabolites, including hydroxyphenylpropionic, hydroxyphenylacetic, hydroxycinnamic, hydroxybenzoic and hydroxyhippuric acids were also identified. Depending of the type of metabolite, maximum urinary excretion was attained at different time in comparison to the control group in the course of the 24-h period of urine excretion, allowing us to establish the onset of microbial metabolism. 2010 Elsevier Inc. All rights reserved.

Combination Chemoprevention with Grape Antioxidants

PubMed Central

Singh, Chandra K.; Siddiqui, Imtiaz A.; El-Abd, Sabah; Mukhtar, Hasan; Ahmad, Nihal

2016-01-01

Antioxidant ingredients present in grape have been extensively investigated for their cancer chemopreventive effects. However, much of the work has been done on individual ingredients, especially focusing on resveratrol and quercetin. Phytochemically, whole grape represents a combination of numerous phytonutrients. Limited research has been done on the possible synergistic/additive/antagonistic interactions among the grape constituents. Among these phytochemical constituents of grapes, resveratrol, quercetin, kaempferol, catechin, epicatechin, and anthocyanins (cyanidin and malvidin) constitute more than 70% of the grape polyphenols. Therefore, these have been relatively well-studied for their chemopreventive effects against a variety of cancers. While a wealth of information is available individually on cancer chemopreventive/anti-proliferative effects of resveratrol and quercetin, limited information is available regarding the other major constituents of grape. Studies have also suggested that multiple grape antioxidants, when used in combination, alone or with other agents/drugs show synergistic or additive anti-proliferative response. Based on strong rationale emanating from published studies, it seems probable that a combination of multiple grape-ingredients alone or together with other agents could impart ‘additive synergism’ against cancer. PMID:26829056

Phytochemical profiles and antioxidant activity of 27 cultivars of tea.

PubMed

Zeng, Liang; Luo, Liyong; Li, Hongjun; Liu, Ruihai

2017-08-01

Tea, rich in phytochemicals, has been suggested to have human health benefits. The phenolic profiles, antioxidant and antiproliferative activities of 27 tea cultivars were determined. Wide ranges of variation were found in analyzed cultivars for the contents of water-soluble phenolics (121.6-223.7 mg/g dry weight (DW)), total catechins (TC) (90.5-177.2 mg/g DW), antioxidant activities (PSC values 627.3-2332.3 μmol of vitamin C equiv/g DW, ORAC values (1865.1-3489.3 μmol of vitamin C equiv/g DW), CAA values (37.7-134.3 μmol of QE/g DW without PBS wash and 25.3-75.4 μmol of QE/g DW with PBS wash) and antiproliferative activity (53.0-90.8% at the concentration of 400 μg/mL extracts). The PSC, ORAC and CAA values were significantly correlated with phenolics, epicatechin gallate (ECG), CC and TC. Knowledge of specific differences among tea cultivars is important for breeding tea cultivars and gives sights to its potential application to promote health.

Profiles of phenolic compounds and purine alkaloids during the development of seeds of Theobroma cacao cv. Trinitario.

PubMed

Pereira-Caro, Gema; Borges, Gina; Nagai, Chifumi; Jackson, Mel C; Yokota, Takao; Crozier, Alan; Ashihara, Hiroshi

2013-01-16

Changes occurring in phenolic compounds and purine alkaloids, during the growth of seeds of cacao (Theobroma cacao) cv. Trinitario, were investigated using HPLC-MS/MS. Extracts of seeds with a fresh weight of 125, 700, 1550, and 2050 mg (stages 1-4, respectively) were analyzed. The phenolic compounds present in highest concentrations in developing and mature seeds (stages 3 and 4) were flavonols and flavan-3-ols. Flavan-3-ols existed as monomers of epicatechin and catechin and as procyanidins. Type B procyanidins were major components and varied from dimers to pentadecamer. Two anthocyanins, cyanidin-3-O-arabinoside and cyanidin-3-O-galactoside, along with the N-phenylpropernoyl-l-amino acids, N-caffeoyl-l-aspartate, N-coumaroyl-l-aspartate, N-coumaroyl-3-hydroxytyrosine (clovamide), and N-coumaroyltyrosine (deoxyclovamide), and the purine alkaloids theobromine and caffeine, were present in stage 3 and 4 seeds. Other purine alkaloids, such as theophylline and additional methylxanthines, did not occur in detectable quantities. Flavan-3-ols were the only components to accumulate in detectable quantities in young seeds at developmental stages 1 and 2.

Impact of roasting on the flavan-3-ol composition, sensory-related chemistry, and in vitro pancreatic lipase inhibitory activity of cocoa beans.

PubMed

Stanley, Todd H; Van Buiten, Charlene B; Baker, Scott A; Elias, Ryan J; Anantheswaran, Ramaswamy C; Lambert, Joshua D

2018-07-30

Roasting is an important cocoa processing step, but has been reported to reduce the polyphenol content in the beans. We investigated the impact of whole-bean roasting on the polyphenol content, aroma-related chemistry, and in vitro pancreatic lipase (PL) inhibitory activity of cocoa under a range of roasting conditions. Total phenolics, (-)-epicatechin, and proanthocyanidin (PAC) dimer - pentamer content was reduced by roasting. By contrast, roasting at 150 °C or greater increased the levels of catechin and PAC hexamers and heptamers. These compounds have greater PL inhibitory potency. Consistent with these changes in PAC composition and this previous data, we found that roasting at 170 °C time-dependently increased PL inhibitory activity. Cocoa aroma-related compounds increased with roasting above 100 °C, whereas deleterious sensory-related compounds formed at more severe temperatures. Our results indicate that cocoa roasting can be optimized to increase the content of larger PACs and anti-PL activity, while maintaining a favorable aroma profile. Copyright © 2018 Elsevier Ltd. All rights reserved.

Analysis of Cocoa Proanthocyanidins Using Reversed Phase High-Performance Liquid Chromatography and Electrochemical Detection: Application to Studies on the Effect of Alkaline Processing.

PubMed

Stanley, Todd H; Smithson, Andrew T; Neilson, Andrew P; Anantheswaran, Ramaswamy C; Lambert, Joshua D

2015-07-01

Flavan-3-ols and proanthocyanidins play a key role in the health beneficial effects of cocoa. Here, we developed a new reversed phased high-performance liquid chromatography-electrochemical detection (HPLC-ECD) method for the analysis of flavan-3-ols and proanthocyanidins of degree of polymerization (DP) 2-7. We used this method to examine the effect of alkalization on polyphenol composition of cocoa powder. Treatment of cocoa powder with NaOH (final pH 8.0) at 92 °C for up to 1 h increased catechin content by 40%, but reduced epicatechin and proanthocyanidins by 23-66%. Proanthocyanidin loss could be modeled using a two-phase exponential decay model (R(2) > 0.7 for epicatchin and proanthocyanidins of odd DP). Alkalization resulted in a significant color change and 20% loss of total polyphenols. The present work demonstrates the first use of HPLC-ECD for the detection of proanthocyanidins up to DP 7 and provides an initial predictive model for the effect of alkali treatment on cocoa polyphenols.

Protein Binding and Astringent Taste of a Polymeric Procyanidin, 1,2,3,4,6-Penta-O-galloyl-β-D-glucopyranose, Castalagin and Grandinin

PubMed Central

Hofmann, Thomas; Glabasnia, Arne; Schwarz, Bernd; Wisman, Kimberly N.; Gangwer, Kelly A.; Hagerman, Ann E.

2008-01-01

The objective of the present investigation was to examine oral astringency and protein binding activity of four structurally well-defined tannins, namely procyanidin (epicatechin16(4→8)catechin), pentagalloyl glucose (1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose), castalagin, and grandinin, representing the three main structural categories of tannins, the proanthocyanidins, the gallotannins, and the ellagitannins. Astringency threshold and dose response were determined by the half-tongue test using a trained human panel. Protein binding stoichiometry and relative affinity were determined using radioiodinated bovine serum albumin in precipitation or competitive binding assays. Procyanidin and pentagalloyl glucose were perceived as highly astringent compounds and had relatively steep dose response curves but castalagin and grandinin had a lower mass threshold for detection. In vitro, procyanidin was the most effective protein precipitating agent, and grandinin the least. Increasing the temperature increased protein precipitation by the hydrolysable tannins, especially grandinin. All four polyphenols had higher relative affinity for proline-rich proteins than for bovine serum albumin. PMID:17147439

Extraction, detection, and quantification of flavano-ellagitannins and ethylvescalagin in a Bordeaux red wine aged in oak barrels.

PubMed

Saucier, Cedric; Jourdes, Michael; Glories, Yves; Quideau, Stephane

2006-09-20

An extraction procedure and an analytical method have been developed to detect and quantify for the first time a series of ellagitannin derivatives formed in wine during aging in oak barrels. The method involves a preliminary purification step on XAD7 HP resin followed by a second purification step on TSK 40 HW gel. The resulting extract is analyzed for compound identification and quantitative determination by high-performance liquid chromatography-electrospray ionization-mass spectrometry in single ion recording mode. Reference compounds, which are accessible through hemisynthesis from the oak C-glycosidic ellagitannin vescalagin, were used to build calibration curves, and chlorogenic acid was selected as an internal standard. This method enabled us to estimate the content of four flavano-ellagitannins and that of another newly identified wine polyphenol, beta-1-O-ethylvescalagin, in a Bordeaux red wine aged for 18 months in oak barrels. All five ellagitannin derivatives are derived from the nucleophilic substitution reaction of vescalagin with the grape flavan-3-ols catechin and epicatechin or ethanol.

Bioavailability and pharmacokinetic profile of grape pomace phenolic compounds in humans.

PubMed

Castello, Fabio; Costabile, Giuseppina; Bresciani, Letizia; Tassotti, Michele; Naviglio, Daniele; Luongo, Delia; Ciciola, Paola; Vitale, Marilena; Vetrani, Claudia; Galaverna, Gianni; Brighenti, Furio; Giacco, Rosalba; Del Rio, Daniele; Mena, Pedro

2018-05-15

Grape pomace, the major byproduct of the wine and juice industry, is a relevant source of bioactive phenolic compounds. However, polyphenol bioavailability in humans is not well understood, and the inter-individual variability in the production of phenolic metabolites has not been comprehensively assessed to date. The pharmacokinetic and excretive profiles of phenolic metabolites after the acute administration of a drink made from red grape pomace was here investigated in ten volunteers. A total of 35 and 28 phenolic metabolites were quantified in urine and plasma, respectively. The main circulating metabolites included phenyl-γ-valerolactones, hydroxybenzoic acids, simple phenols, hydroxyphenylpropionic acids, hydroxycinnamates, and (epi)catechin phase II conjugates. A high inter-individual variability was shown both in urine and plasma samples, and different patterns of circulating metabolites were unravelled by applying unsupervised multivariate analysis. Besides the huge variability in the production of microbial metabolites of colonic origin, an important variability was observed due to phase II conjugates. These results are of interest to further understand the potential health benefits of phenolic metabolites on individual basis. Copyright © 2018 Elsevier Inc. All rights reserved.

On-line HPLC-DPPH screening method for evaluation of radical scavenging phenols extracted from apples (Malus domestica L.).

PubMed

Bandoniene, Donata; Murkovic, Michael

2002-04-24

An on-line HPLC-DPPH screening method for phenolic antioxidants in apple methanol/water (80:20, v/v) extracts was applied. The determination of antioxidants was based on a decrease in absorbance at 515 nm after postcolumn reaction of HPLC-separated antioxidants with the 2,2'-diphenyl-1-picrylhydrazyl radicals (DPPH*). Each of the antioxidants separated by the HPLC column was observed as a negative peak corresponding to its antioxidative activity. The on-line method was applied for quantitative analysis of the antioxidants. A linear dependence of negative peak area on concentration of the reference antioxidants was observed. For validation of the on-line method the limit of detection, LOD (microg/mL), and the limit of quantification, LOQ (microg/mL), of the phenolic compounds were determined. Comparison of the UV and DPPH radical quenching chromatograms with authentic compounds identified catechin, chlorogenic acid, caffeic acid, epicatechin, and phloridzin in the apple cultivars (Lobo, Golden Delicious, and Boskoop), and the distribution of total antioxidant activity was calculated.

Antioxidant Activities of Selected Berries and Their Free, Esterified, and Insoluble-Bound Phenolic Acid Contents

PubMed Central

2018-01-01

To explore the potential of berries as natural sources of bioactive compounds, the quantities of free, esterified, and insoluble-bound phenolic acids in a number of berries were determined. In addition, the antioxidant activities of the berries were determined using 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, ferric reducing antioxidant power, and Trolox equivalent antioxidant capacity assays, in addition to determination of their metal ion chelating activities. Furthermore, several phenolic compounds were detected using high-performance liquid chromatography. Of the 6 tested berries, black chokeberry and blackberry exhibited the strongest antioxidant activities, and the various berry samples were found to contain catechin, caffeic acid, p-coumaric acid, epicatechin, vanillic acid, quercitrin, resveratrol, morin, naringenin, and apigenin. Moreover, the antioxidant activities and total phenolic contents of the fractions containing insoluble-bound phenolic acids were higher than those containing the free and esterified phenolic acids. The results imply that the insoluble-bound fractions of these berries are important natural sources of antioxidants for the preparation of functional food ingredients and preventing diseases associated with oxidative stress. PMID:29662846

Effects of Vinification Techniques Combined with UV-C Irradiation on Phenolic Contents of Red Wines.

PubMed

Tahmaz, Hande; Söylemezoğlu, Gökhan

2017-06-01

Red wines are typically high in phenolic and antioxidant capacity and both of which can be increased by vinification techniques. This study employed 3 vinification techniques to assess the increase in phenolic compounds and antioxidant capacity. Wines were obtained from Boğazkere grape cultivar by techniques of classical maceration, cold maceration combined with ultraviolet light (UV) irradiation, and thermovinification combined with UV irradiation and changes in phenolic contents were examined. Total phenolic and anthocyanin contents and trolox equivalent antioxidant capacity of wines were measured spectrophotometrically and phenolic contents (+)-catechin, (-)-epicatechin, rutin, quercetin, trans-resveratrol, and cis-resveratrol were measured by High Pressure Liquid Chromatography with Diode Array Detection (HPLC-DAD). As a result of the study, the highest phenolic content except for quercetin was measured in the wines obtained by thermovinification combined with UV irradiation. We demonstrated that the highest phenolic compounds with health effect, total phenolic compounds, total anthocyanin, and antioxidant activity were obtained from thermovinification with UV-C treatment than classical wine making. © 2017 Institute of Food Technologists®.

Correlation between changes in polyphenol composition of peels and incidence of CO₂ skin burning of 'Cameo' apples as influenced by controlled atmosphere storage.

PubMed

Harb, Jamil; Kittemann, Dominikus; Neuwald, Daniel Alexandre; Hoffmann, Thomas; Schwab, Wilfried

2013-04-17

'Cameo' apples stored under high CO₂ levels suffer from "skin burning". Accordingly, this study is aimed to correlate the incidence of skin burning with different polyphenols. After harvest, apples were sorted into bad- and good-colored fruit and further stored under either high (3%) or low (0.7%) CO₂ level. At frequent intervals, fruit were assessed for incidence of skin burning and relative concentrations of various polyphenols. Results clearly show that bad-colored apples stored under high CO₂ level had the highest incidence percentage. Concerning the polyphenol profile, good-colored and healthy apples had significantly higher concentrations of certain polyphenols, including cyanidin-3-galactoside and rutin. However, bad-colored and injured apples had significantly higher concentrations of another set of polyphenols, including phloridzin, epicatechin, and (epi)catechin→(epi)catechin isomers. Taking into account that quercetins and cyanidins account for more than 80% of antioxidants, it is logical to assume that these polyphenols might give protection to good-colored apples against skin burning.

Combination chemoprevention with grape antioxidants.

PubMed

Singh, Chandra K; Siddiqui, Imtiaz A; El-Abd, Sabah; Mukhtar, Hasan; Ahmad, Nihal

2016-06-01

Antioxidant ingredients present in grape have been extensively investigated for their cancer chemopreventive effects. However, much of the work has been done on individual ingredients, especially focusing on resveratrol and quercetin. Phytochemically, whole grape represents a combination of numerous phytonutrients. Limited research has been done on the possible synergistic/additive/antagonistic interactions among the grape constituents. Among these phytochemical constituents of grapes, resveratrol, quercetin, kaempferol, catechin, epicatechin, and anthocyanins (cyanidin and malvidin) constitute more than 70% of the grape polyphenols. Therefore, these have been relatively well studied for their chemopreventive effects against a variety of cancers. While a wealth of information is available individually on cancer chemopreventive/anti-proliferative effects of resveratrol and quercetin, limited information is available regarding the other major constituents of grape. Studies have also suggested that multiple grape antioxidants, when used in combination, alone or with other agents/drugs show synergistic or additive anti-proliferative response. Based on strong rationale emanating from published studies, it seems probable that a combination of multiple grape ingredients alone or together with other agents could impart 'additive synergism' against cancer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Immobilization of flavan-3-ols onto sensor chips to study their interactions with proteins and pectins by SPR

NASA Astrophysics Data System (ADS)

Watrelot, Aude A.; Tran, Dong Tien; Buffeteau, Thierry; Deffieux, Denis; Le Bourvellec, Carine; Quideau, Stéphane; Renard, Catherine M. G. C.

2016-05-01

Interactions between plant polyphenols and biomacromolecules such as proteins and pectins have been studied by several methods in solution (e.g. isothermal titration calorimetry, dynamic light scattering, nuclear magnetic resonance and spectrophotometry). Herein, these interactions were investigated in real time by Surface Plasmon Resonance (SPR) analysis after immobilization of flavan-3-ols onto a sensor chip surface. (-)-epicatechin, (+)-catechin and flavan-3-ol oligomers with an average degree of polymerization of 2 and 8 were chemically modified using N-(2-(tritylthio)ethyl)propiolamide in order to introduce a spacer unit onto the catecholic B ring. Modified flavan-3-ols were then immobilized onto a carboxymethylated dextran surface (CM5). Immobilization was validated and further verified by evaluating flavan-3-ol interaction with bovine serum albumin (BSA), poly-L-proline or commercial pectins. BSA was found to have a stronger association with monomeric flavan-3-ols than oligomers. SPR analysis of selected flavan-3-ols immobilized onto CM5 sensor chips showed a stronger association for citrus pectins than apple pectins, regardless of flavan-3-ol degree of polymerization.

Additive Capacity of [6]-Shogaol and Epicatechin To Trap Methylglyoxal.

PubMed

Huang, Qiju; Wang, Pei; Zhu, Yingdong; Lv, Lishuang; Sang, Shengmin

2017-09-27

Methylglyoxal (MGO), a reactive dicarbonyl species, is thought to contribute to the development of long-term pathological diabetes as a direct toxin or as an active precursor of advanced glycation end products (AGEs). Trapping MGO by dietary phenols to inhibit the MGO induced AGE formation is an approach for alleviating diabetic complications. The present study investigated whether dietary compounds with different structures and active sites have the additive capacity to trap MGO. Ginger phenolic constituent [6]-shogaol and tea flavonoid (-)-epicatechin were selected and tested under simulated physiological conditions, showing that they additively trapped about 41% MGO at a concentration of 10 μM within 24 h. Furthermore, whether [6]-shogaol and epicatechin can retain their MGO trapping efficacy in vivo or a biotransformation limits their MGO trapping capacity remain virtually unknown. An acute mouse study was carried out by giving a single dose of [6]-shogaol, epicatechin, and the combination of both ([6]-shogaol + epicatechin) through oral gavage. A mono-MGO adduct of [6]-shogaol was identified from [6]-shogaol and [6]-shogaol + epicatechin treated mice, and mono- and di-MGO adducts of epicatechin and its metabolite, 3'-O-methyl epicatichin, were detected in urine samples collected from epicatechin and [6]-shogaol + epicatechin treated mice. To our knowledge, this is the first study demonstrating the additive MGO trapping efficacy of [6]-shogaol and epicatechin and that [6]-shogaol and epicatechin retained their MGO trapping capacity in mice.

Epicatechin attenuates atherosclerosis and exerts anti-inflammatory effects on diet-induced human-CRP and NFκB in vivo.

PubMed

Morrison, Martine; van der Heijden, Roel; Heeringa, Peter; Kaijzel, Eric; Verschuren, Lars; Blomhoff, Rune; Kooistra, Teake; Kleemann, Robert

2014-03-01

Previous studies investigating flavanol-rich foods provide indications for potential cardioprotective effects of these foods, but the effects of individual flavanols remain unclear. We investigated whether the flavanol epicatechin can reduce diet-induced atherosclerosis, with particular emphasis on the cardiovascular risk factors dyslipidaemia and inflammation. ApoE*3-Leiden mice were fed a cholesterol-containing atherogenic diet with or without epicatechin (0.1% w/w) to study effects on early- and late-stage atherosclerosis (8 w and 20 w). In vivo effects of epicatechin on diet-induced inflammation were studied in human-CRP transgenic mice and NFκB-luciferase reporter mice. Epicatechin attenuated atherosclerotic lesion area in ApoE*3-Leiden mice by 27%, without affecting plasma lipids. This anti-atherogenic effect of epicatechin was specific to the severe lesion types, with no effect on mild lesions. Epicatechin mitigated diet-induced increases in plasma SAA (in ApoE*3-Leiden mice) and plasma human-CRP (in human-CRP transgenic mice). Microarray analysis of aortic gene expression revealed an attenuating effect of epicatechin on several diet-induced pro-atherogenic inflammatory processes in the aorta (e.g. chemotaxis of cells, matrix remodelling), regulated by NFκB. These findings were confirmed immunohistochemically by reduced lesional neutrophil content in HCE, and by inhibition of diet-induced NFκB activity in epicatechin-treated NFκB-luciferase reporter mice. Epicatechin attenuates development of atherosclerosis and impairs lesion progression from mild to severe lesions in absence of an effect on dyslipidaemia. The observed reduction of circulating inflammatory risk factors by epicatechin (e.g. SAA, human-CRP), as well as its local anti-inflammatory activity in the vessel wall, provide a rationale for epicatechin's anti-atherogenic effects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

(-)-Epicatechin-induced relaxation of isolated human saphenous vein: Roles of K+ and Ca2+ channels.

PubMed

Marinko, Marija; Jankovic, Goran; Nenezic, Dragoslav; Milojevic, Predrag; Stojanovic, Ivan; Kanjuh, Vladimir; Novakovic, Aleksandra

2018-02-01

In this study, we aimed to investigate relaxant effect of flavanol (-)-epicatechin on the isolated human saphenous vein (HSV), as a part of its cardioprotective action, and to define the mechanisms underlying this vasorelaxation. (-)-Epicatechin induced a concentration-dependent relaxation of HSV pre-contracted by phenylephrine. Among K + channel blockers, 4-aminopyridine, margatoxin, and iberiotoxin significantly inhibited relaxation of HSV, while glibenclamide considerably reduced effects of the high concentrations of (-)-epicatechin. Additionally, (-)-epicatechin relaxed contraction induced by 80 mM K + , whereas in the presence of nifedipine produced partial relaxation of HSV rings pre-contracted by phenylephrine. In Ca 2+ -free solution, (-)-epicatechin relaxed contraction induced by phenylephrine, but had no effect on contraction induced by caffeine. A sarcoplasmic reticulum Ca 2+ -ATPase inhibitor, thapsigargin, significantly reduced relaxation of HSV produced by (-)-epicatechin. These results demonstrate that (-)-epicatechin produces endothelium-independent relaxation of isolated HSV rings. Vasorelaxation to (-)-epicatechin probably involves activation of 4-aminopyridine- and margatoxin-sensitive K V channels, BK Ca channels, and at least partly, K ATP channels. In addition, not only the inhibition of extracellular Ca 2+ influx, but regulation of the intracellular Ca 2+ release, via inositol-trisphosphate receptors and reuptake into sarcoplasmic reticulum, via stimulation of Ca 2+ -ATPase, as well, most likely participate in (-)-epicatechin-induced relaxation of HSV. Copyright © 2017 John Wiley & Sons, Ltd.

NMR and molecular modeling: application to wine ageing

NASA Astrophysics Data System (ADS)

Saucier, C.; Pianet, I.; Laguerre, M.; Glories, Y.

1998-02-01

Red wine contains polyphenols called tannins which are very important for its taste and longevity. These polymers consist in repeating units of catechin and its epimer epicatechin. During ageing, slow condensation reactions take place which lead to new chemical structures. Among the possible reactions, we have focused our attention on acetaldehyde cross-linking. Catechin was used as a model for the production of polymers with acetaldehyde. Two reaction product fractions have been isolated by liquid chromatography. Mass measurement indicated that these fractions contain dimers. NMR (1D and 2D) and molecular modelling were then used to study the structure and conformations of these products. The first product consist in a pure dimer with the two catechin moieties connected with an ethyl bridge on the carbon 6 and 8. The second fraction was a mixture of two dimers (50/50). NMR measurements showed that it could be two symmetrical dimers involving the same carbon for each catechin moiety (6 or8). Le vin rouge contient des polyphénols appelés tanins qui sont très importants pour son goût et sa longévité. Il s'agit principalement de polymères de catéchine et d'épicatéchine. Durant le vieillissement du vin, des réactions de condensation interviennent lentement et conduisent à de nouvelles structures. Parmi les réactions possibles, nous avons plus spécialement étudié la polymérisation par pontage avec l'éthanal. La catéchine a été utilisée comme modèle de tannin et mise en présence d'éthanal en milieu acide proche du vin. Deux fractions de produits de réaction ont été isolées par chromatographie liquide. La spectrométrie de masse a révélé la présence de dimères. La RMN (1D et 2D) et la modélisation moléculaire ont ensuite été utilisées pour déterminer la structure et la conformation de ces produits. La première fraction a été identifiée comme étant un dimère de deux unités catéchines reliées par un pont éthyle par leur carbones6 et8. La seconde fraction isolée est un mélange de deux dimères (50/50). Les mesures RMN montrent qu'il pourrait s'agir de dimères symétriques reliés par le même carbone (6-6 et 8-8).

Bioavailability of epicatechin and effects on nitric oxide metabolites of an apple flavanol-rich extract supplemented beverage compared to a whole apple puree: a randomized, placebo-controlled, crossover trial.

PubMed

Hollands, Wendy J; Hart, David J; Dainty, Jack R; Hasselwander, Oliver; Tiihonen, Kirsti; Wood, Richard; Kroon, Paul A

2013-07-01

Flavanol-rich foods are known to exert beneficial effects on cardiovascular health. The biological effects depend on bioavailability of flavanols which may be influenced by food matrix and dose ingested. We compared the bioavailability and dose-response of epicatechin from whole apple and an epicatechin-rich extract, and the effects on plasma and urinary nitric oxide (NO) metabolites. In a randomized, placebo-controlled, crossover trial, subjects consumed drinks containing 70 and 140 mg epicatechin from an apple extract and an apple puree containing 70 mg epicatechin. Blood and urine samples were collected for 24 h post ingestion. Maximum plasma concentration, AUC(0-24 h) , absorption and urinary excretion were all significantly higher after ingestion of both epicatechin drinks compared with apple puree (p < 0.05). Time to maximum plasma concentration was significantly later for the puree compared with the drinks (p < 0.01). Epicatechin bioavailability was >2-fold higher after ingestion of the 140 mg epicatechin drink compared to the 70 mg epicatechin drink (p < 0.05). Excretion of NO metabolites was higher for all test products compared with placebo, which was significant for the high dose drink (p = 0.016). Oral bioavailability of apple epicatechin increases at higher doses, is reduced by whole apple matrix and has the potential to increase NO bioavailability. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

(–)-Epicatechin enhances fatigue resistance and oxidative capacity in mouse muscle

PubMed Central

Nogueira, Leonardo; Ramirez-Sanchez, Israel; Perkins, Guy A; Murphy, Anne; Taub, Pam R; Ceballos, Guillermo; Villarreal, Francisco J; Hogan, Michael C; Malek, Moh H

2011-01-01

Abstract The flavanol (–)-epicatechin, a component of cacao (cocoa), has been shown to have multiple health benefits in humans. Using 1-year-old male mice, we examined the effects of 15 days of (–)-epicatechin treatment and regular exercise on: (1) exercise performance, (2) muscle fatigue, (3) capillarity, and (4) mitochondrial biogenesis in mouse hindlimb and heart muscles. Twenty-five male mice (C57BL/6N) were randomized into four groups: (1) water, (2) water–exercise (W-Ex), (3) (–)-epicatechin ((–)-Epi), and (4) (–)-epicatechin–exercise ((–)-Epi-Ex). Animals received 1 mg kg−1 of (–)-epicatechin or water (vehicle) via oral gavage (twice daily). Exercise groups underwent 15 days of treadmill exercise. Significant increases in treadmill performance (∼50%) and enhanced in situ muscle fatigue resistance (∼30%) were observed with (–)-epicatechin. Components of oxidative phosphorylation complexes, mitofilin, porin, nNOS, p-nNOS, and Tfam as well as mitochondrial volume and cristae abundance were significantly higher with (–)-epicatechin treatment for hindlimb and cardiac muscles than exercise alone. In addition, there were significant increases in skeletal muscle capillarity. The combination of (–)-epicatechin and exercise resulted in further increases in oxidative phosphorylation-complex proteins, mitofilin, porin and capillarity than (–)-epicatechin alone. These findings indicate that (–)-epicatechin alone or in combination with exercise induces an integrated response that includes structural and metabolic changes in skeletal and cardiac muscles resulting in greater endurance capacity. These results, therefore, warrant the further evaluation of the underlying mechanism of action of (–)-epicatechin and its potential clinical application as an exercise mimetic. PMID:21788351

Regulation of NF-{kappa}B activity in astrocytes: effects of flavonoids at dietary-relevant concentrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spilsbury, Alison; Vauzour, David; Spencer, Jeremy P.E.

Highlights: Black-Right-Pointing-Pointer We tested the hypothesis that low concentrations of flavonoids inhibit NF-{kappa}B in astrocytes. Black-Right-Pointing-Pointer Primary cultured astrocytes possess a functional {kappa}B-system, measured using luciferase assays. Black-Right-Pointing-Pointer Seven flavonoids (100 nM-1 {mu}M) failed to reduce NF-{kappa}B activity in astrocytes. Black-Right-Pointing-Pointer Four flavonoids (100 nM-1 {mu}M) failed to reduce TNFa-stimulated NF-{kappa}B activity in astrocytes. Black-Right-Pointing-Pointer (-)-Epicatechin did not regulate nuclear translocation of the NF-{kappa}B subunit, p65. -- Abstract: Neuroinflammation plays an important role in the progression of neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Sustained activation of nuclear transcription factor {kappa}B (NF-{kappa}B) is thought to play an importantmore » role in the pathogenesis of neurodegenerative disorders. Flavonoids have been shown to possess antioxidant and anti-inflammatory properties and we investigated whether flavonoids, at submicromolar concentrations relevant to their bioavailability from the diet, were able to modulate NF-{kappa}B signalling in astrocytes. Using luciferase reporter assays, we found that tumour necrosis factor (TNF{alpha}, 150 ng/ml) increased NF-{kappa}B-mediated transcription in primary cultures of mouse cortical astrocytes, which was abolished on co-transfection of a dominant-negative I{kappa}B{alpha} construct. In addition, TNF{alpha} increased nuclear localisation of p65 as shown by immunocytochemistry. To investigate potential flavonoid modulation of NF-{kappa}B activity, astrocytes were treated with flavonoids from different classes; flavan-3-ols ((-)-epicatechin and (+)-catechin), flavones (luteolin and chrysin), a flavonol (kaempferol) or the flavanones (naringenin and hesperetin) at dietary-relevant concentrations (0.1-1 {mu}M) for 18 h. None of the flavonoids modulated constitutive or TNF{alpha}-induced NF-{kappa}B activity. Therefore, we conclude that NF-{kappa}B signalling in astrocytes is not a major target for flavonoids.« less

Dark chocolate inhibits platelet isoprostanes via NOX2 down-regulation in smokers.

PubMed

Carnevale, R; Loffredo, L; Pignatelli, P; Nocella, C; Bartimoccia, S; Di Santo, S; Martino, F; Catasca, E; Perri, L; Violi, Francesco

2012-01-01

Dark chocolate is reported to decrease platelet activation but the underlying mechanism is still undefined. Dark chocolate is rich in polyphenols that could exert an antiplatelet action via inhibition of oxidative stress. The aim of the present study was to assess if dark chocolate inhibits platelet reactive oxidant species (ROS) formation and platelet activation. Twenty healthy subjects (HS) and 20 smokers were randomly allocated to receive 40 g of dark (cocoa > 85%) or milk chocolate (cocoa < 35%) in a cross-over, single-blind study. There was an interval of 7 days between the two phases of the study. At baseline and 2 h after chocolate ingestion, platelet recruitment (PR), platelet ROS, platelet isoprostane 8-ISO-prostaglandin F2α (8-iso-PGF2α), Thromboxane (TxA2) and platelet activation of NOX2, the catalytic sub-unit of NADPH oxidase, and serum epicatechin were measured. Compared with HS, smokers showed enhanced PR, platelet formation of ROS and eicosanoids and NOX2 activation. After dark chocolate, platelet ROS (-48%, P < 0.001), 8-iso-PGF2α (-10%, P < 0.001) and NOX2 activation (-22%, P < 0.001) significantly decreased; dark chocolate did not affect platelet variables in HS. No effect of milk chocolate was detected in both groups. Serum epicatechin increased after dark chocolate in HS (from 0.454 ± 0.3 nm to 118.3 ± 53.7 nm) and smokers (from 0.5 ± 0.28 nm to 120.9 ± 54.2 nm). Platelet incubation with 0.1-10 μm catechin significantly reduced PR, platelet 8-iso-PGF2α and ROS formation and NOX2 activation only in platelets from smokers. Dark chocolate inhibits platelet function by lowering oxidative stress only in smokers; this effect seems to be dependent on its polyphenolic content. © 2011 International Society on Thrombosis and Haemostasis.

Maillard reaction and enzymatic browning affect the allergenicity of Pru av 1, the major allergen from cherry (Prunus avium).

PubMed

Gruber, Patrick; Vieths, Stefan; Wangorsch, Andrea; Nerkamp, Jörg; Hofmann, Thomas

2004-06-16

The influence of thermal processing and nonenymatic as well as polyphenoloxidase-catalyzed browning reaction on the allergenicity of the major cherry allergen Pru av 1 was investigated. After thermal treatment of the recombinant protein rPru av 1 in the absence or presence of carbohydrates, SDS-PAGE, enzyme allergosorbent tests, and inhibition assays revealed that thermal treatment of rPru av 1 alone did not show any influence on the IgE-binding activity of the protein at least for 30 min, thus correlating well with the refolding of the allergen in buffer solution as demonstrated by CD spectroscopic experiments. Incubation of the protein with starch and maltose also showed no effect on IgE-binding activity, whereas reaction with glucose and ribose and, even more pronounced, with the carbohydrate breakdown products glyceraldehyde and glyoxal induced a strong decrease of the IgE-binding capacity of rPru av 1. In the second part of the study, the effect of polyphenoloxidase-catalyzed oxidation of polyphenols on food allergen activity was investigated. Incubation of rPru av 1 with epicatechin in the presence of tyrosinase led to a drastic decrease in IgE-binding activity of the protein. Variations of the phenolic compound revealed caffeic acid and epicatechin as the most active inhibitors of the IgE-binding activity of rPru av 1, followed by catechin and gallic acid, and, finally, by quercetin and rutin, showing significantly lower activity. On the basis of these data, reactive intermediates formed during thermal carbohydrate degradation as well as during enzymatic polyphenol oxidation are suggested as the active chemical species responsible for modifying nucleophilic amino acid side chains of proteins, thus inducing an irreversible change in the tertiary structure of the protein and resulting in a loss of conformational epitopes of the allergen.

In Depth Proteome Analysis of Ripening Muscadine Grape Berry cv. Carlos Reveals Proteins Associated with Flavor and Aroma Compounds.

PubMed

Kambiranda, Devaiah; Basha, Sheikh M; Singh, Rakesh K; He, Huan; Calvin, Kate; Mercer, Roger

2016-09-02

Ripening in nonclimacteric fruits such as grape involves complex chemical changes that have a profound influence on the accumulation of flavor and aroma compounds distinct to a particular grape genotype. In this study, proteome characterization of wine type bronze muscadine grape (Vitis rotundifolia cv. Carlos), primarily grown in the Southeastern United States was performed during berry ripening. Stage-specific protein expression was obtained among different stages of berries. Differential analysis showed the expression of 522 proteins that regulate diverse biological processes and metabolic pathways. Of these, 30 proteins are associated with the production of key phenolic compounds, whereas 25 are associated with the production of muscadine aroma compounds. These proteins are involved in the phenylpropanoid pathway, terpene synthesis, fatty acid derived volatiles and esters that affect muscadine berry flavor and aroma characteristics. Further, gene expression analysis during ripening validated the expression pattern of 12 proteins. Catechin, epicatechin, and four stilbenes were quantified to correlate observed proteome changes. This study not only revealed biochemical changes during muscadine berry ripening but also offers indicators for marker-assisted breeding to enhance organoleptic properties of muscadine grape to improve its flavor and aroma properties.

Antioxidant activity of commercial food grade tannins exemplified in a wine model.

PubMed

Ricci, Arianna; Olejar, Kenneth J; Parpinello, Giuseppina P; Mattioli, Alessia U; Teslić, Nemanja; Kilmartin, Paul A; Versari, Andrea

2016-12-01

Although commercial tannins are widely used in foods and beverages, an improved understanding of the structure and composition of vegetable tannins is needed to promote the exploitation of agri-food by-products and waste and their valorisation in more sustainable industrial applications. This study aims to characterise the phytochemical composition and antioxidant activity of 13 food grade tannins using multiple analytical approaches, including spectrophotometry and HPLC-ECD to determine the amount of targeted polyphenolic compounds. Moreover, the antioxidant activity of tannins was assessed in terms of radical scavenging activity (DPPH• assay), reducing power (FRAP assay), and redox properties (cyclic voltammetry, CV). A statistical univariate and multivariate correlation analysis was performed on 17 parameters including tannin content (range: 0.71-1.62 mM), gallic acid, (+)-catechin, syringic acid and (‒)-epicatechin. The compositional profile of tannins was related to their chemical moiety, antioxidant activity and the botanical origin of the extracts. In particular, the CV signal at 500 mV was highly correlated with DPPH• value due to the catechol ring of flavonoids and trigalloyl moieties of gallic acid-based compounds. Practical examples of tannins application in winemaking are discussed.

Polyphenolic compounds in date fruit seed (Phoenix dactylifera): characterisation and quantification by using UPLC-DAD-ESI-MS.

PubMed

Habib, Hosam M; Platat, Carine; Meudec, Emmanuelle; Cheynier, Veronique; Ibrahim, Wissam H

2014-04-01

Date fruit seeds have been demonstrated to possess high antioxidant activities due to their high content of flavonoids and phenolic compounds. The objective of this work was to identify and quantify the phenolic composition of date seeds. Two UPLC-DAD-ESI-MS analyses were performed on the seed of the Khalas variety as follows: (1) an analysis of simple phenolic compounds [phenolic acids, hydroxycinnamic acids, flavonols, flavones, flavan-3-ols (monomers, dimers and trimers)]; and (2) an analysis of all flavan-3-ols (monomers, and proanthocyanidin oligomers and polymers) after depolymerisation. The amount of total phenolic compounds before depolymerisation was found to be 2.194 ± 0.040 g kg(-1) date seed. The analysis of flavan-3-ol monomers and constitutive units of proanthocyanidins after depolymerisation revealed 50.180 ± 1.360 g kg(-1) flavan-3-ols with 46.800 ± 1.012 g kg(-1) epicatechin and 3.380 ± 0.349 g kg(-1) catechin. The results indicate that date seeds are a very rich source of bioactive compounds, thus constituting strong candidates for functional food additives and nutraceuticals. © 2013 Society of Chemical Industry.

Isolation and quantification of oligomeric pyranoanthocyanin-flavanol pigments from red wines by combination of column chromatographic techniques.

PubMed

He, Jingren; Santos-Buelga, Celestino; Mateus, Nuno; de Freitas, Victor

2006-11-17

A combination of column chromatography on Toyopearl gel HW-40 (S) and polyamide resin has been developed for the preparative isolation and further determination of pyranoanthocyanins of oligomeric nature formed after reaction between anthocyanins and different flavanols in a complex wine matrix. Polyamide chromatography was found to be exceptionally useful to separate oligomeric pyanoanthocyanins from other classes of wine flavonoids and polymerized pigments into an advanced state of purity for further identification and quantification by HPLC-diode array detector coupled with electrospray ionization mass spectrometry (HPLC-DAD/ESI-MS). Fractionation on Toyopearl gel chromatography allowed the separation of pyranoanthocyanins bearing the same flavanols (catechin, epicatechin and procyanidin dimers) but with different anthocyanin moieties (either acylated or non-acylated in the glucose residue) in order to allow further isolation of individual oligomeric pigments on C18 chromatography. A quantitative procedure for analyzing the major pyranoanthocyanin-flavanol derivatives in different aged wines is proposed for the first time. Results obtained showed good reproducibility and recovery regarding sample pretreatment and quantitative method for all analyzed oligomeric pyranoanthocyanins. The combination of these two chromatographic separations is likely to be applicable to the preparative isolation of other anthocyanin-derived pigments.

Characterization of critical physical and mechanical properties of freeze-dried grape powder for development of a clinical patient delivery system.

PubMed

Hu, Daniel; Haware, Rahul V; Hamad, Mazen L; Morris, Kenneth R

2013-02-01

Grapes are hypothesized to be a "food medicine." Freeze-dried grape powder (FDGP) is being used to test clinical activity for a variety of applications and a reproducible and reliable delivery system was required. The FDGP was characterized using traditional physico-chemical methods to generate the data needed to identify its primary liability, i.e. moisture sorption. Above a threshold level of moisture content (~25% w/w, at RT), the material becomes both difficult to handle and exhibits significant degradation of several potentially clinically important chemical components (catechin, epicatechin, resveratrol). A moisture sorption isotherm was then used to tie the threshold to the exposure relative humidity above which this occurs. Kinetic uptake studies were used to estimate the maximum safe exposure time at a given humidity (a square root time dependence of moisture uptake was observed). Armed with this knowledge, a FDGP compact coated with a compression coat [100% bees wax or combinations of carnauba wax (70%) with HPC (30%) or Avicel(®) PH 102 (30%) or lactose monohydrate (30%)] was developed that will insure the shelf life of the material without the need for special handling for approximately more than 3 months.

Protective effects of Merlot red wine extract and its major polyphenols in PC12 cells under oxidative stress conditions.

PubMed

Martín, Sara; González-Burgos, Elena; Carretero, M Emilia; Gómez-Serranillos, M Pilar

2013-01-01

The potential effect of the extracts from free-run and pressed Merlot red wine has been evaluated in PC12 cells under oxidative stress situation. Comparing both vinification process, pressed Merlot red wine extract possessed higher neuroprotective activity than the free run wine, possibly attributed to the major content in all global polyphenolic families. High performance liquid chromatography determination of individual polyphenols showed that the major compounds found in Merlot red wine extract were quercetin, catechin, epicatechin, tyrosol, gallic acid, and procyanidins. Pretreatments with these polyphenolic compounds (0.25 mM and 0.1 mM, 24 h) significantly increased cell viability of H(2)O(2) and Fenton reaction treated cells. Moreover, these polyphenols attenuated ROS production and decreased the Redox Index of glutathione (RI = GSSG/GSH + GSSG) in cells treated only with Fenton reaction. Furthermore, some polyphenols induced antioxidant enzymes activity and protein expression. Quercetin was the most active. These results support the beneficial effects of red wine extracts and some of its polyphenols under oxidative stress conditions. This research provides evidences of the preventive properties of wine extracts and its major polyphenols under oxidative stress conditions. © 2012 Institute of Food Technologists®

Evaluation of ozonation technique for pesticide residue removal and its effect on ascorbic acid, cyanidin-3-glucoside, and polyphenols in apple (Malus domesticus) fruits.

PubMed

Swami, Saurabh; Muzammil, Raunaq; Saha, Supradip; Shabeer, Ahammed; Oulkar, Dasharath; Banerjee, Kaushik; Singh, Shashi Bala

2016-05-01

Ozonated water dip technique was evaluated for the detoxification of six pesticides, i.e., chlorpyrifos, cypermethrin, azoxystrobin, hexaconazole, methyl parathion, and chlorothalonil from apple fruits. Results revealed that ozonation was better than washing alone. Ozonation for 15 min decreased residues of the test pesticides in the range of from 26.91 to 73.58%, while ozonation for 30 min could remove the pesticide residues by 39.39-95.14 % compared to 19.05-72.80 % by washing. Cypermethrin was the least removed pesticide by washing as well as by ozonation. Chlorothalonil, chlorpyrifos, and azoxystrobin were removed up to 71.45-95.14 % in a 30-min ozonation period. In case of methyl parathion removal, no extra advantage could be obtained by ozonation. The HPLC analysis indicated that ozonation also affected adversely the ascorbic acid and cyanidin-3-glucoside content of apples. However, 11 polyphenols studied showed a mixed trend. Gallic acid, 3,4-dihydroxybenzoic acid, catechin, epicatechin, p-coumaric acid, quercetin-3-O-glucoside, quercetin, and kaempferol were found to decrease while syringic acid, rutin, and resveratrol were found to increase in 30-min ozonation.

Proanthocyanidins-Will they effectively restrain conspicuous bacterial strains devolving on urinary tract infection?

PubMed

Jagannathan, Venkataseshan; Viswanathan, Pragasam

2018-05-18

Struvite or infection stones are one of the major clinical burdens among urinary tract infection, which occur due to the interaction between microbes and urine mineral components. Numerous urinary tract infection (UTI) causing microbes regulate through biofilm formation for survival from host defense, it is often found difficult in its eradication with simple anti-microbial agents and also the chance of recurrence and resistance development is significantly high. Cranberry consumption and maintenance of urinary tract health have been supported by clinical, epidemiological, and mechanistic studies. It predominantly contains proanthocyanidins that belong to the class of polyphenols with repeating catechin and epicatechin monomeric units. Numerous studies have correlated proanthocyanidin consumption and prevention of bacterial adhesion to uroepithelial cells. Quorum sensing (QS) is the prime mechanism that drives bacteria to coordinate biofilm development and virulence expression. Reports have shown that proanthocyanidins are effective in disrupting cell-cell communication by quenching signal molecules. Overall, this review assesses the merits of proanthocyanidins and its effective oppression on adherence, motility, QS, and biofilm formation of major UTI strains such as Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis by comparing and evaluating results from many significant findings. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of engineered yeast for biosorption of beer haze-active polyphenols.

PubMed

Cejnar, Rudolf; Hložková, Kateřina; Jelínek, Lukáš; Kotrba, Pavel; Dostálek, Pavel

2017-02-01

Compared to most other alcoholic beverages, the shelf life of beer is much more limited due to its instability in the bottle. That instability is most likely to appear as turbidity (haze), even sedimentation, during storage. The haze in beer is mostly caused by colloidal particles formed by interactions between proteins and polyphenols within the beer. Therefore, beers are usually stabilized by removing at least one of these components. We developed and constructed a Saccharomyces cerevisiae strain with a proline-rich QPF peptide attached to the cell wall, using the C-terminal anchoring domain of α-agglutinin. The QPF peptide served to bind polyphenols during fermentation and, thus, to decrease their concentration. Strains displaying QPF were able to bind about twice as much catechin and epicatechin as a control strain displaying only the anchoring domain. All these experiments were done with model solutions. Depending on the concentration of yeast, uptake of polyphenols was 1.7-2.5 times higher. Similarly, the uptake of proanthocyanidins was increased by about 20 %. Since the modification of yeasts with QPF did not affect their fermentation performance under laboratory conditions, the display of QPF appears to be an approach to increase the stability of beer.

Microspore development of three coniferous species: affinity of nuclei for flavonoids.

PubMed

Feucht, Walter; Treutter, Dieter; Dithmar, Heike; Polster, Jürgen

2008-12-01

The nuclear localization of blue-staining flavanols was investigated histochemically throughout microsporogenesis in yellow cypress (Callitropsis nootkatensis (D. Don) Oerst., formerly Cupressus nootkatensis), juniper (Juniperus communis L.) and yew (Taxus baccata L.). During meiotic development, both the cytoplasm and nuclei of microspores of all species contained varying amounts of flavanols; however, the flavanols were largely confined to the nuclei in microspores just released from tetrads. Quantification by HPLC analysis indicated that, in all species, catechin and epicatechin were the dominant nuclear flavanols. At the early free microspore stage, the nuclear flavanols were barely detectable in all species, but they increased fivefold on incubation in the presence of 0.1 mM benzylaminopurine (BA) or zeatin. Histochemical studies revealed that, in addition to non-fluorescing flavanols, microspores contained yellow-fluorescing flavonoids, which yielded a distinct HPLC flavonoid profile for each species. In yellow cypress, the hydrolyzed flavonoids were identified as quercetin, apigenin, kaempferol and luteolin, whereas only quercetin and myricetin were found in microspores of juniper and in anthers of yew. Application of a UV-VIS titration technique revealed that the aglycone quercetin seems to interact more strongly with histone H3 than either glycoside rutin or kaempferol.

Antioxidant dietary fibre recovery from Brazilian Pinot noir grape pomace.

PubMed

Beres, Carolina; Simas-Tosin, Fernanda F; Cabezudo, Ignacio; Freitas, Suely P; Iacomini, Marcello; Mellinger-Silva, Caroline; Cabral, Lourdes M C

2016-06-15

Brazilian grape pomace was extracted in hot water, and a factorial experiment was used to evaluate polysaccharide recovery. The dependent variables were the temperature, particle size and solute:solvent ratio. Polysaccharide yields varied from 3% to 10%, and the highest sugar content was observed when extraction was carried out at 100 °C from finely sized particles (⩽249 μm) in a 1:12 solute:solvent ratio. The monosaccharide composition of extracts obtained from flours were, on average, Rha:Ara:Xyl:Man:Gal:Glc:GalA in a 3:32:2:13:11:20:19 M ratio, with varying Glc:GalA ratios. (13)C NMR and HSQC spectra confirmed the presence of pectic- and glucose-based polysaccharides in the extracts. Phenolic compounds were found after pomace extraction, and catechin, gallic acid and epicatechin were the principal compounds identified. The extracts also had ABTS radical scavenging capacity (from 8.00 to 46.60 mMol Trolox/100 g pomace). These findings indicate that these grape pomace flours are rich in antioxidant dietary fibre and have a potential use as food ingredients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electron-beam irradiation effects on phytochemical constituents and antioxidant capacity of pecan kernels [ Carya illinoinensis (Wangenh.) K. Koch] during storage.

PubMed

Villarreal-Lozoya, Jose E; Lombardini, Leonardo; Cisneros-Zevallos, Luis

2009-11-25

Pecans kernels (Kanza and Desirable cultivars) were irradiated with 0, 1.5, and 3.0 kGy using electron-beam (E-beam) irradiation and stored under accelerated conditions [40 degrees C and 55-60% relative humidity (RH)] for 134 days. Antioxidant capacity (AC) using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays, phenolic (TP) and condensed tannin (CT) content, high-performance liquid chromatography (HPLC) phenolic profile, tocopherol content, peroxide value (PV), and fatty acid profiles were determined during storage. Irradiation decreased TP and CT with no major detrimental effects in AC. Phenolic profiles after hydrolysis were similar among treatments (e.g., gallic and ellagic acid, catechin, and epicatechin). Tocopherol content decreased with irradiation (>21 days), and PV increased at later stages (>55 days), with no change in fatty acid composition among treatments. Color lightness decreased, and a reddish brown hue developed during storage. A proposed mechanism of kernel oxidation is presented, describing the events taking place. In general, E-beam irradiation had slight effects on phytochemical constituents and could be considered a potential tool for pecan kernel decontamination.

Effect of fermentation and drying on cocoa polyphenols.

PubMed

Albertini, Barbara; Schoubben, Aurélie; Guarnaccia, Davide; Pinelli, Filippo; Della Vecchia, Mirco; Ricci, Maurizio; Di Renzo, Gian Carlo; Blasi, Paolo

2015-11-18

Cocoa seed polyphenols have demonstrated interesting beneficial effects in humans. Most polyphenols contained in fresh seeds are chemically modified during fermentation, drying, and cocoa powder or chocolate production. The improvement of these procedures to obtain a high-polyphenol-content cocoa is highly desirable. To this aim, a field investigation on the effect of fermentation and natural drying on fine flavor National cocoa (cacao Nacional) was performed. Cocoa seeds were fermented for 6 days and, every day, samples were sun-dried and analyzed for polyphenol content and antioxidant power. During the first 2 days of fermentation, Folin-Ciocalteu and FRAP tests evidenced a significant reduction of polyphenol content and antioxidant capacity, respectively. Changes during the following days of fermentation were less significant. Epicatechin, the most studied member of the catechin family, followed a similar pathway of degradation. Data confirmed the high impact of fermentation and drying on cocoa seed polyphenols. Fermentation and drying are, on the one hand, necessary to obtain cocoa flavor and palatability but, on the other hand, are responsible for greatly compromising polyphenol content. To obtain high-polyphenol-content cocoa, the existing fermentation, drying, and manufacturing protocols should be scientifically reviewed to understand and modify the critical steps.

Determination of phenolic compounds content and antioxidant activity in skin, pulp, seed, cane and leaf of five native grape cultivars in West Azerbaijan province, Iran.

PubMed

Farhadi, Khalil; Esmaeilzadeh, Forough; Hatami, Mehdi; Forough, Mehrdad; Molaie, Rahim

2016-05-15

In the present work, the phenolic compounds content and antioxidant activity in the skin, pulp, seed, cane and leaf of one international (Muscat) and five native (Hosseini, Ghara Shira, Agh Shani, Ghara Shani and Ghara Ghandome) grape cultivated in West Azerbaijan, Iran were investigated. Ghara Shani grape skin was found to contain the highest content of total phenolic and anthocyanin and cane of Ghara Shani contains the highest amount of flavonoid. A remarkable DPPH radical scavenging activity up to 95% and consequently, the lowest IC50 was found for skin of Ghara Shani. According to RP-HPLC experiments, the highest concentration of phenolic compounds was identified as catechin (945 μg/g), epicatechin (482 μg/g), gallic acid (319 μg/g) and resveratrol (29.8 μg/g) in skin of Ghara Shani, quercetin in cane of Ghara Shani (956 μg/g), rutin in skin of Ghara Shira (298 μg/g) and caffeic acid in cane of Ghara Shira (17.4 μg/g). Copyright © 2015 Elsevier Ltd. All rights reserved.

Short-term postharvest carbon dioxide treatments induce selective molecular and metabolic changes in grape berries.

PubMed

Becatti, Elisa; Chkaiban, Lamia; Tonutti, Pietro; Forcato, Claudio; Bonghi, Claudio; Ranieri, Anna Maria

2010-07-14

Detached wine grapes ( Vitis vinifera cv. 'Trebbiano', white skinned) were treated for 3 days with 30 kPa of CO(2) and then transferred to air for an additional 9 days to partially dehydrate (about 20% weight loss). At the end of the CO(2) treatment on withering berries, total polyphenols and flavonoids were maintained in the skin, but to a more limited extent in the pulp. An induction of the proanthocyanidin synthesis appeared to be one of the responses to the treatment because both (+)-catechin and (-)-epicatechin concentrations increased in the skin. The skin and pulp of the grape berries showed different molecular responses to a high CO(2) treatment. As revealed by microarray hybridizations, 217 and 75 genes appeared differentially expressed in the skin and pulp of treated samples, respectively. Functional categorization and gene enrichment analyses pointed out that epicarp cells undergo more pronounced changes in transcript profiling at the end of the incubation period. Highly represented categories in both tissues were related to protein, stress, transcript, RNA, and hormone (ethylene, ABA) metabolism. Fermentation, CHO metabolism, and redox regulation functional categories were represented only in the skin.

Profiling of the Major Phenolic Compounds and Their Biosynthesis Genes in Sophora flavescens Aiton.

PubMed

Lee, Jeongyeo; Jung, Jaeeun; Son, Seung-Hyun; Kim, Hyun-Bi; Noh, Young-Hee; Min, Sung Ran; Park, Kun-Hyang; Kim, Dae-Soo; Park, Sang Un; Lee, Haeng-Soon; Kim, Cha Young; Kim, Hyun-Soon; Lee, Hyeong-Kyu; Kim, HyeRan

2018-01-01

Sophorae Radix ( Sophora flavescens Aiton) has long been used in traditional medicine in East Asia due to the various biological activities of its secondary metabolites. Endogenous contents of phenolic compounds (phenolic acid, flavonol, and isoflavone) and the main bioactive compounds of Sophorae Radix were analyzed based on the qualitative HPLC analysis and evaluated in different organs and at different developmental stages. In total, 11 compounds were detected, and the composition of the roots and aerial parts (leaves, stems, and flowers) was significantly different. trans-Cinnamic acid and p -coumaric acid were observed only in the aerial parts. Large amounts of rutin and maackiain were detected in the roots. Four phenolic acid compounds (benzoic acid, caffeic acid, ferulic acid, and chlorogenic acid) and four flavonol compounds (kaempferol, catechin hydrate, epicatechin, and rutin) were higher in aerial parts than in roots. To identify putative genes involved in phenolic compounds biosynthesis, a total of 41 transcripts were investigated. Expression patterns of these selected genes, as well as the multiple isoforms for the genes, varied by organ and developmental stage, implying that they are involved in the biosynthesis of various phenolic compounds both spatially and temporally.

Mediterranean Way of Drinking and Longevity.

PubMed

Giacosa, Attilio; Barale, Roberto; Bavaresco, Luigi; Faliva, Milena Anna; Gerbi, Vincenzo; La Vecchia, Carlo; Negri, Eva; Opizzi, Annalisa; Perna, Simone; Pezzotti, Mario; Rondanelli, Mariangela

2016-01-01

The relation between alcohol consumption and mortality is a J-shaped curve in most of the many studies published on this topic. The Copenhagen Prospective Population Studies demonstrated in the year 2000 that wine intake may have a beneficial effect on all cause mortality that is additive to that of alcohol. Wine contains various poliphenolic substances which may be beneficial for health and in particular flavonols (such as myricetin and quercetin), catechin and epicatechin, proanthocyanidins, anthocyanins, various phenolic acids and the stilbene resveratrol. In particular, resveratrol seems to play a positive effect on longevity because it increases the expression level of Sirt1, besides its antioxidant, anti-inflammatory and anticarcinogenic properties. Moderate wine drinking is part of the Mediterranean diet, together with abundant and variable plant foods, high consumption of cereals, olive oil as the main (added) fat and a low intake of (red) meat. This healthy diet pattern involves a "Mediterranean way of drinking," that is a regular, moderate wine consumption mainly with food (up to two glasses a day for men and one glass for women). Moderate wine drinking increases longevity, reduces the risk of cardiovascular diseases and does not appreciably influence the overall risk of cancer.

Profiling of the Major Phenolic Compounds and Their Biosynthesis Genes in Sophora flavescens Aiton

PubMed Central

Son, Seung-Hyun; Kim, Hyun-Bi; Noh, Young-Hee; Min, Sung Ran; Park, Kun-Hyang; Kim, Dae-Soo; Lee, Haeng-Soon; Kim, Cha Young; Lee, Hyeong-Kyu

2018-01-01

Sophorae Radix (Sophora flavescens Aiton) has long been used in traditional medicine in East Asia due to the various biological activities of its secondary metabolites. Endogenous contents of phenolic compounds (phenolic acid, flavonol, and isoflavone) and the main bioactive compounds of Sophorae Radix were analyzed based on the qualitative HPLC analysis and evaluated in different organs and at different developmental stages. In total, 11 compounds were detected, and the composition of the roots and aerial parts (leaves, stems, and flowers) was significantly different. trans-Cinnamic acid and p-coumaric acid were observed only in the aerial parts. Large amounts of rutin and maackiain were detected in the roots. Four phenolic acid compounds (benzoic acid, caffeic acid, ferulic acid, and chlorogenic acid) and four flavonol compounds (kaempferol, catechin hydrate, epicatechin, and rutin) were higher in aerial parts than in roots. To identify putative genes involved in phenolic compounds biosynthesis, a total of 41 transcripts were investigated. Expression patterns of these selected genes, as well as the multiple isoforms for the genes, varied by organ and developmental stage, implying that they are involved in the biosynthesis of various phenolic compounds both spatially and temporally. PMID:29686587

Inhibition of FLT3 Expression by Green Tea Catechins in FLT3 Mutated-AML Cells

PubMed Central

Ly, Bui Thi Kim; Chi, Hoang Thanh; Yamagishi, Makoto; Kano, Yasuhiko; Hara, Yukihiko; Nakano, Kazumi; Sato, Yuko; Watanabe, Toshiki

2013-01-01

Acute myeloid leukemia (AML) is a heterogeneous disease characterized by a block in differentiation and uncontrolled proliferation. FLT3 is a commonly mutated gene found in AML patients. In clinical trials, the presence of a FLT3-ITD mutation significantly correlates with an increased risk of relapse and dismal overall survival. Therefore, activated FLT3 is a promising molecular target for AML therapies. In this study, we have shown that green tea polyphenols including (−)-epigallocatechin-3-gallate (EGCG), (−)-epigallocatechin (EGC), and (−)-epicatechin-3-gallate (ECG) suppress the proliferation of AML cells. Interestingly, EGCG, EGC and ECG showed the inhibition of FLT3 expression in cell lines harboring FLT3 mutations. In the THP-1 cells harboring FLT3 wild-type, EGCG showed the suppression of cell proliferation but did not suppress the expression of FLT3 even at the concentration that suppress 100% cell proliferation. Moreover, EGCG-, EGC-and ECG-treated cells showed the suppression of MAPK, AKT and STAT5 phosphorylation. Altogether, we suggest that green tea polyphenols could serve as reagents for treatment or prevention of leukemia harboring FLT3 mutations. PMID:23840454

Cinnamon bark proanthocyanidins as reactive carbonyl scavengers to prevent the formation of advanced glycation endproducts.

PubMed

Peng, Xiaofang; Cheng, Ka-Wing; Ma, Jinyu; Chen, Bo; Ho, Chi-Tang; Lo, Clive; Chen, Feng; Wang, Mingfu

2008-03-26

Cinnamon bark has been reported to be effective in the alleviation of diabetes through its antioxidant and insulin-potentiating activities. In this study, the inhibitory effect of cinnamon bark on the formation of advanced glycation endproducts (AGEs) was investigated in a bovine serum albumin (BSA)-glucose model. Several phenolic compounds, such as catechin, epicatechin, and procyanidin B2, and phenol polymers were identified from the subfractions of aqueous cinnamon extract. These compounds showed significant inhibitory effects on the formation of AGEs. Their antiglycation activities were not only brought about by their antioxidant activities but also related to their trapping abilities of reactive carbonyl species such as methylglyoxal (MGO), an intermediate reactive carbonyl of AGE formation. Preliminary study on the reaction between MGO and procyanidin B2 revealed that MGO-procyanidin B2 adducts are primary products which are supposed to be stereoisomers. This is the first report that proanthocyanidins can effectively scavenge reactive carbonyl species and thus inhibit the formation of AGEs. As proanthocyanidins behave in a similar fashion as aminoguanidine (AG), the first AGE inhibitor explored in clinical trials, they show great potential to be developed as agents to alleviate diabetic complications.

Varietal differences among the polyphenol profiles of seven table grape cultivars studied by LC-DAD-MS-MS.

PubMed

Cantos, Emma; Espín, Juan Carlos; Tomás-Barberán, Francisco A

2002-09-25

Polyphenols present in red table grape varieties Red Globe, Flame Seedless, Crimson Seedless, and Napoleon, and the white varieties Superior Seedless, Dominga, and Moscatel Italica were analyzed by HPLC-DAD-MS. The anthocyanins peonidin 3-glucoside, cyanidin 3-glucoside (and their corresponding p-coumaroyl derivatives), malvidin 3-glucoside, petunidin 3-glucoside, and delphinidin 3-glucoside were found. In addition, caffeoyltartaric acid, p-coumaroyltartaric acid, and the flavonols quercetin 3-glucuronide, quercetin 3-rutinoside, quercetin 3-glucoside, kaempferol 3-galactoside, kaempferol 3-glucoside, and isorhamnetin 3-glucoside were detected. Flavan-3-ols were also detected, and were identified as gallocatechin, procyanidin B1, procyanidin B2, procyanidin B4, procyanidin C1, catechin, and epigallocatechin. These phenolics were present only in the skin, as the flesh of these grape cultivars was almost devoid of these compounds. Anthocyanins were the main phenolics in red grapes ranging from 69 (Crimson Seedless) to 151 (Flame Seedless) mg/kg fresh weight of grapes, whereas flavan-3-ols were the most abundant phenolics in the white varieties ranging from 52 (Dominga) to 81 (Moscatel Italica) mg/kg fresh weight of grapes. Total phenolics ranged from 115 (Dominga) to 361 (Flame Seedless) mg/kg fresh weight of grapes. This means that a serving of unpeeled table grapes (200 g) could provide up to 72 mg of total phenolics (Flame Seedless). These results indicate that the intake of unpeeled table grapes should be recommended in dietary habits as a potential source of antioxidant and anticarcinogenic phenolic compounds.

A biochemical, electrocardiographic, electrophoretic, histopathological and in vitro study on the protective effects of (-)epicatechin in isoproterenol-induced myocardial infarcted rats.

PubMed

Prince, Ponnian Stanely Mainzen

2011-12-05

(-) Epicatechin rich foods and (-) epicatechin improve cardiovascular function. Consumption of diets rich in flavonoids is associated with reduced risk of cardiovascular diseases. Oxidative stress resulting from increased production of free radicals associated with decreased levels of antioxidants in the myocardium plays a major role in the pathogenesis of myocardial infarction. This study aims to evaluate the preventive effects of (-) epicatechin on oxidative stress in isoproterenol-induced myocardial infarcted rats. Male Wistar rats were pretreated with (-) epicatechin (20mg/kg body weight) daily for 21 days. After pretreatment, isoproterenol (100mg/kg body weight) was injected into the rats at an interval of 24h for two days to induce myocardial infarction. Isoproterenol induced rat's electrocardiogram showed elevated ST segments and significant increase in the activity of serum creatine kinase-MB, level of serum troponin-T and increased intensities of serum lactate dehydrogenase 1 and 2-isoenzymes. The rats also showed significant increased levels of heart lipid peroxidation products and significant decreased activities of heart superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and levels of reduced glutathione. Pretreatment with (-) epicatechin revealed significant protective effects on all the biochemical parameters and electrocardiogram investigated. Histopathology of myocardium confirmed the present findings. The in vitro study on the effects of (-) epicatechin on scavenging free radical 1,1-diphenyl-2-picrylhydrazyl revealed the free radical scavenging potential of (-) epicatechin. Thus, (-) epicatechin exerts protective effects against isoproterenol-induced oxidative stress thereby reducing cardiac tissue damage by its free radical scavenging and antioxidant effects. Copyright © 2011 Elsevier B.V. All rights reserved.

Identification of Intestinal UDP-Glucuronosyltransferase Inhibitors in Green Tea (Camellia sinensis) Using a Biochemometric Approach: Application to Raloxifene as a Test Drug via In Vitro to In Vivo Extrapolation.

PubMed

Tian, Dan-Dan; Kellogg, Joshua J; Okut, Neşe; Oberlies, Nicholas H; Cech, Nadja B; Shen, Danny D; McCune, Jeannine S; Paine, Mary F

2018-05-01

Green tea ( Camellia sinensis ) is a popular beverage worldwide, raising concern for adverse interactions when co-consumed with conventional drugs. Like many botanical natural products, green tea contains numerous polyphenolic constituents that undergo extensive glucuronidation. As such, the UDP-glucuronosyltransferases (UGTs), particularly intestinal UGTs, represent potential first-pass targets for green tea-drug interactions. Candidate intestinal UGT inhibitors were identified using a biochemometrics approach, which combines bioassay and chemometric data. Extracts and fractions prepared from four widely consumed teas were screened (20-180 μ g/ml) as inhibitors of UGT activity (4-methylumbelliferone glucuronidation) in human intestinal microsomes; all demonstrated concentration-dependent inhibition. A biochemometrics-identified fraction rich in UGT inhibitors from a representative tea was purified further and subjected to second-stage biochemometric analysis. Five catechins were identified as major constituents in the bioactive subfractions and prioritized for further evaluation. Of these catechins, (-)-epicatechin gallate and (-)-epigallocatechin gallate showed concentration-dependent inhibition, with IC 50 values (105 and 59 μ M, respectively) near or below concentrations measured in a cup (240 ml) of tea (66 and 240 μ M, respectively). Using the clinical intestinal UGT substrate raloxifene, the K i values were ∼1.0 and 2.0 μ M, respectively. Using estimated intestinal lumen and enterocyte inhibitor concentrations, a mechanistic static model predicted green tea to increase the raloxifene plasma area under the curve up to 6.1- and 1.3-fold, respectively. Application of this novel approach, which combines biochemometrics with in vitro-in vivo extrapolation, to other natural product-drug combinations will refine these procedures, informing the need for further evaluation via dynamic modeling and clinical testing. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

Selectivity mapping of the binding sites of (E)-resveratrol imprinted polymers using structurally diverse polyphenolic compounds present in Pinot noir grape skins.

PubMed

Hashim, Shima N N S; Schwarz, Lachlan J; Danylec, Basil; Potdar, Mahesh K; Boysen, Reinhard I; Hearn, Milton T W

2016-12-01

This investigation describes a general procedure for the selectivity mapping of molecularly imprinted polymers, using (E)-resveratrol-imprinted polymers as the exemplar, and polyphenolic compounds present in Pinot noir grape skin extracts as the test compounds. The procedure is based on the analysis of samples generated before and after solid-phase extraction of (E)-resveratrol and other polyphenols contained within the Pinot noir grape skins using (E)-resveratrol-imprinted polymers. Capillary reversed-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionisation tandem mass spectrometry (ESI MS/MS) was then employed for compound analysis and identification. Under optimised solid-phase extraction conditions, the (E)-resveratrol-imprinted polymer showed high binding affinity and selectivity towards (E)-resveratrol, whilst no resveratrol was bound by the corresponding non-imprinted polymer. In addition, quercetin-3-O-glucuronide and a dimer of catechin-methyl-5-furfuraldehyde, which share some structural features with (E)-resveratrol, were also bound by the (E)-resveratrol-imprinted polymer. Polyphenols that were non-specifically retained by both the imprinted and non-imprinted polymer were (+)-catechin, a B-type procyanidin and (-)-epicatechin. The compounds that did not bind to the (E)-resveratrol molecularly imprinted polymer had at least one of the following molecular characteristics in comparison to the (E)-resveratrol template: (i) different spatial arrangements of their phenolic hydroxyl groups, (ii) less than three or more than four phenolic hydroxyl groups, or (iii) contained a bulky substituent moiety. The results show that capillary RP-HPLC in conjunction with ESI MS/MS represent very useful techniques for mapping the selectivity of the binding sites of imprinted polymer. Moreover, this procedure permits performance monitoring of the characteristics of molecularly imprinted polymers intended for solid-phase extraction of bioactive and nutraceutical molecules from diverse agricultural waste sources. Copyright © 2016 Elsevier B.V. All rights reserved.

Wine as a biological fluid: history, production, and role in disease prevention.

PubMed

Soleas, G J; Diamandis, E P; Goldberg, D M

1997-01-01

Wine has been part of human culture for 6,000 years, serving dietary and socio-religious functions. Its production takes place on every continent, and its chemical composition is profoundly influenced by enological techniques, the grape cultivar from which it originates, and climatic factors. In addition to ethanol, which in moderate consumption can reduce mortality from coronary heart disease by increasing high-density lipoprotein cholesterol and inhibiting platelet aggregation, wine (especially red wine) contains a range of polyphenols that have desirable biological properties. These include the phenolic acids (p-coumaric, cinnamic, caffeic, gentisic, ferulic, and vanillic acids), trihydroxy stilbenes (resveratrol and polydatin), and flavonoids (catechin, epicatechin, and quercetin). They are synthesized by a common pathway from phenylalanine involving polyketide condensation reactions. Metabolic regulation is provided by competition between resveratrol synthase and chalcone synthase for a common precursor pool of acyl-CoA derivatives. Polymeric aggregation gives rise, in turn to the viniferins (potent antifungal agents) and procyanidins (strong antioxidants that also inhibit platelet aggregation). The antioxidant effects of red wine and of its major polyphenols have been demonstrated in many experimental systems spanning the range from in vitro studies (human low-density lipoprotein, liposomes, macrophages, cultured cells) to investigations in healthy human subjects. Several of these compounds (notably catechin, quercetin, and resveratrol) promote nitric oxide production by vascular endothelium; inhibit the synthesis of thromboxane in platelets and leukotriene in neutrophils, modulate the synthesis and secretion of lipoproteins in whole animals and human cell lines, and arrest tumour growth as well as inhibit carcinogenesis in different experimental models. Target mechanisms to account for these effects include inhibition of phospholipase A2 and cyclo-oxygenase, inhibition of phosphodiesterase with increase in cyclic nucleotide concentrations, and inhibition of several protein kinases involved in cell signalling. Although their bioavailability remains to be fully established, red wine provides a more favourable milieu than fruits and vegetables, their other dietary source in humans.

Galloylated polyphenols efficiently reduce alpha-tocopherol radicals in a phospholipid model system composed of sodium dodecyl sulfate (SDS) micelles.

PubMed

Pazos, Manuel; Torres, Josep Lluís; Andersen, Mogens L; Skibsted, Leif H; Medina, Isabel

2009-06-10

The ability of several polyphenolic fractions from grape ( Vitis vinifera ) pomace, pine ( Pinus pinaster ) bark, and witch hazel ( Hammamelis virginiana ) bark to repair alpha-tocopherol (alpha-TOH) through reduction of the alpha-tocopheroxyl radical was investigated in a homogeneous hexane system and a phospholipid-like system based on SDS micelles. These natural polyphenols were compared with pure related phenolics (epicatechin, gallic acid, epigallocatechin gallate, quercetin, and rutin) and ascorbic acid, which is a substance with a well-recognized capacity for regenerating alpha-TOH. alpha-Tocopheroxyl radicals were monitored and quantified by electron spin resonance (ESR) spectroscopy in the absence and presence of phenolics. Polyphenols from grape and pine bark were essentially catechin monomers and proanthocyanidins differing in the content of galloyl residues; those from pine bark had a negligible degree of galloylation. Polyphenolic fractions from witch hazel bark were composed of approximately 80% hydrolyzable tannins rich in galloyl moieties, together with a smaller amount of catechin monomers and proanthocyanidins. In the homogeneous hexane system, polyphenols from grape and pine bark exhibited similar activities, reducing the alpha-tocopheroxyl radicals by over 27-40%, whereas phenols from witch hazel were more highly effective, reducing 80% of alpha-TOH. In contrast, pine bark polyphenols were found to be significantly less active than the grape fractions in SDS micelles, reducing 30 and 70% of alpha-tocopheroxyl radicals, respectively. Polyphenolic fractions from witch hazel were also able to reduce the highest amount of alpha-TOH in SDS-micelles. The reducing capacity on alpha-tocopheroxyl radical of polyphenolic fractions was found to be pH-dependent and more effective at higher pH in the range of pH studied (5.8-7.8). These results stress the potential role of polyphenols, in particular those rich in galloyl groups, to maintain intact endogenous alpha-TOH in biological membranes through reduction of alpha-tocopheroxyl radicals.

Evaluation of the Antidiabetic Activity and Chemical Composition of Geranium collinum Root Extracts-Computational and Experimental Investigations.

PubMed

Numonov, Sodik; Edirs, Salamet; Bobakulov, Khayrulla; Qureshi, Muhammad Nasimullah; Bozorov, Khurshed; Sharopov, Farukh; Setzer, William N; Zhao, Haiqing; Habasi, Maidina; Sharofova, Mizhgona; Aisa, Haji Akber

2017-06-13

The root of Geranium collinum Steph is known in Tajik traditional medicine for its hepatoprotective, antioxidant, and anti-inflammatory therapeutic effects. The present study was conducted to evaluate of potential antidiabetic, antioxidant activities, total polyphenolic and flavonoid content from the different extracts (aqueous, aqueous-ethanolic) and individual compounds isolated of the root parts of G. collinum . The 50% aqueous-ethanolic extract possesses potent antidiabetic activity, with IC 50 values of 0.10 μg/mL and 0.09 μg/mL for the enzymes protein-tyrosine phosphatase (1B PTP-1B) and α-glucosidase, respectively. Phytochemical investigations of the 50% aqueous-ethanolic extract of G. collinum , led to the isolation of ten pure compounds identified as 3,3',4,4'-tetra- O -methylellagic acid ( 1 ), 3,3'-di- O -methylellagic acid ( 2 ), quercetin ( 3 ), caffeic acid ( 4 ), (+)-catechin ( 5 ), (-)-epicatechin ( 6 ), (-)-epigallocatechin ( 7 ), gallic acid ( 8 ), β-sitosterol-3- O -β-d-glucopyranoside ( 9 ), and corilagin ( 10 ). Their structures were determined based on 1D and 2D NMR and mass spectrometric analyses. Three isolated compounds exhibited strong inhibitory activity against PTP-1B, with IC 50 values below 0.9 μg/mL, more effective than the positive control (1.46 μg/mL). Molecular docking analysis suggests polyphenolic compounds such as corilagin, catechin and caffeic acid inhibit PTP-1B and β-sitosterol-3- O -β-d-gluco-pyranoside inhibits α-glucosidase. The experimental results suggest that the biological activity of G. collinum is related to its polyphenol contents. The results are also in agreement with computational investigations. Furthermore, the potent antidiabetic activity of the 50% aqueous-ethanolic extract from G. collinum shows promise for its future application in medicine. To the best of our knowledge, we hereby report, for the first time, the antidiabetic activity of G. collinum.

Epicatechin breaks preformed glycated serum albumin and reverses the retinal accumulation of advanced glycation end products.

PubMed

Kim, Junghyun; Kim, Chan-Sik; Moon, Min Kyong; Kim, Jin Sook

2015-02-05

The accumulation of advanced glycation end products (AGEs) is associated with many of the complications of diabetes mellitus, including diabetic retinopathy. AGE-breakers, such as N-phenacylthiazolium and alagebrium, have been proposed as therapeutic agents for reversing the increase in protein crosslinking in diabetes. (-)-Epicatechin is a major dietary flavonoid with a wide range of health-promoting biological activities. The aim of this study was to determine the potential effect of (-)-epicatechin in reducing the burden of AGEs in vitro and in vivo and to evaluate whether the reduced AGE burden could translate into improvement in retinal vascular function in exogenously AGE-injected rats. Glycated human serum albumin was purified from patients with diabetes. The breakdown of the already formed AGEs was studied by treating glycated human serum albumin with (-)-epicatechin. To study the effect of (-)-epicatechin on retinal vascular function, exogenously AGE-injected rats were treated with (-)-epicatechin (50 and 100 mg/kg i.p.) for two weeks. Apoptosis of retinal vascular cells was quantified using TUNEL staining. The AGE load in the retinas was determined via immunohistochemical staining and western blot analysis. (-)-Epicatechin was able to break preformed glycated human serum albumin in vitro as well as reduce AGE accumulation in retinas in vivo in a dose dependent manner. In exogenously AGE-injected rats, treatment with (-)-epicatechin was evidenced by an improved retinal vascular apoptosis. AGE burden in retinas was also reduced upon treatment. This study suggests that (-)-epicatechin could represent a valuable drug for the treatment of diabetic retinopathy by reducing the AGE burden. Copyright © 2014 Elsevier B.V. All rights reserved.

(-)-Epicatechin-induced recovery of mitochondria from simulated diabetes: Potential role of endothelial nitric oxide synthase.

PubMed

Ramírez-Sánchez, Israel; Rodríguez, Alonso; Moreno-Ulloa, Aldo; Ceballos, Guillermo; Villarreal, Francisco

2016-05-01

(-)-Epicatechin increases indicators associated with mitochondrial biogenesis in endothelial cells and myocardium. We investigated endothelial nitric oxide synthase involvement on (-)-epicatechin-induced increases in indicators associated with mitochondrial biogenesis in human coronary artery endothelial cells cultured in normal-glucose and high-glucose media, as well as to restore indicators of cardiac mitochondria from the effects of simulated diabetes. Here, we demonstrate the role of endothelial nitric oxide synthase on (-)-epicatechin-induced increases in mitochondrial proteins, transcription factors and sirtuin 1 under normal-glucose conditions. In simulated diabetes endothelial nitric oxide synthase function, mitochondrial function-associated and biogenesis-associated indicators were adversely impacted by high glucose, effects that were reverted by (-)-epicatechin. As an animal model of type 2 diabetes, 2-month old C57BL/6 mice were fed a high-fat diet for 16 weeks. Fasting and fed blood glucose levels were increased and NO plasma levels decreased. High-fat-diet-fed mice myocardium revealed endothelial nitric oxide synthase dysfunction, reduced mitochondrial activity and markers of mitochondrial biogenesis. The administration of 1 mg/kg (-)-epicatechin for 15 days by oral gavage shifted these endpoints towards control mice values. Results suggest that endothelial nitric oxide synthase mediates (-)-epicatechin-induced increases of indicators associated with mitochondrial biogenesis in endothelial cells. (-)-Epicatechin also counteracts the negative effects that high glucose or simulated type 2 diabetes has on endothelial nitric oxide synthase function. © The Author(s) 2016.

(-) Epicatechin attenuates mitochondrial damage by enhancing mitochondrial multi-marker enzymes, adenosine triphosphate and lowering calcium in isoproterenol induced myocardial infarcted rats.

PubMed

Stanely Mainzen Prince, P

2013-03-01

Cardiac mitochondrial damage plays an important role in the pathology of myocardial infarction. The protective effects of (-) epicatechin on cardiac mitochondrial damage in isoproterenol induced myocardial infarction were evaluated in rats. Rats were pretreated with (-) epicatechin (20 mg/kg body weight) daily for a period of 21 days. After the pretreatment period, isoproterenol (100 mg/kg body weight) was injected subcutaneously into rats twice at an interval of 24 h to induce myocardial infarction. Isoproterenol induced myocardial infarcted rats showed a significant increase in the levels of cardiac diagnostic markers, heart mitochondrial lipid peroxidation, calcium, and a significant decrease in the activities/levels of heart mitochondrial glutathione peroxidase, glutathione reductase, reduced glutathione, isocitrate, succinate, malate, α-ketoglutarate and NADH-dehydrogenases, cytochrome-C-oxidase and adenosine triphosphate. (-) Epicatechin pretreatment showed significant protective effects on all the biochemical parameters evaluated. The in vitro study revealed the superoxide and hydroxyl radical scavenging activity of (-) epicatechin. The possible mechanisms for the beneficial effects of (-) epicatechin on cardiac mitochondria could be attributed to scavenging of free radicals, decreasing calcium, increasing multi-enzymes (antioxidant, tricarboxylic acid cycle and respiratory chain enzymes), reduced glutathione and adenosine triphosphate. Thus, (-) epicatechin attenuated mitochondrial damage in isoproterenol induced myocardial infarcted rats. Copyright © 2012 Elsevier Ltd. All rights reserved.

Association of (+)-catechin and catechin-(4a-8)-catechin with oligopeptides

Treesearch

Tsutomu Hatano; Richard W. Hemingway

1996-01-01

NOE studies on the complexation of (poly)flavanoids with peptides containing proline residues in aqueous solutions reveal site specific approach directed by hydrophobic interaction of the aromatic rings of catechin and its dimer, catechin-(4α→8)-catechin, to conformationally accessible regions of peptides without strong preferencef or interaction...

Extraction and isolation of catechins from tea.

PubMed

Vuong, Quan V; Golding, John B; Nguyen, Minh; Roach, Paul D

2010-11-01

Tea is a major source of catechins, which have become well known for their antioxidant potential. Numerous human, animal, and in vitro studies have linked tea catechins with prevention of certain types of cancers, reduction of the risks for obesity, diabetes, and cardiovascular disease, and improvement of the immune system. Tea catechins are widely used in various neutraceuticals, pharmaceuticals, and cosmetics for either enhancing product shelf-life or for enhancing human health. Thus, the demand for catechins has increased considerably. Catechins have been extracted and isolated from tea leaves by numerous methods through several steps including: treatment of the tea leaves, extraction of catechins from teas into solvents, isolation of catechins from other extracted components, and drying the preparations to obtain catechin extracts in a powder form. This paper outlines the physical and chemical properties of the tea catechins and reviews the extraction steps of the various extraction methods, as a basis to improve and further develop the extraction and isolation of the tea catechins.

Effects of (−)Epicatechin on the Pathology of APP/PS1 Transgenic Mice

PubMed Central

Zeng, Yue-Qin; Wang, Yan-Jiang; Zhou, Xin-Fu

2014-01-01

Background: Alzheimer’s disease (AD) is a multifactorial disorder characterized by the progressive deterioration of neuronal networks. The clearance of Aβ from the brain and anti-inflammation are potential important strategies to prevent and treat disease. In a previous study, we demonstrated the grape seed extract (GSE) could reduce brain Aβ burden and microglia activation, but which polyphenol plays a major role in these events is not known. Here, we tested pharmacological effects of (−)epicatechin, one principle polyphenol compound in GSE, on transgenic AD mice. Methods: APP/PS1 transgenic mice were fed with (−)epicatechin diet (40 mg/kg/day) and curcumin diet (47 mg/kg/day) at 3 months of age for 9 months, the function of liver, Aβ levels in the brain and serum, AD-type neuropathology, plasma levels of inflammatory cytokines were measured. Results: Toward the end of the experiment, we found long-term feeding of (−)epicatechin diet was well tolerated without fatality, changes in food consumption, body weight, or liver function. (−)Epicatechin significantly reduced total Aβ in brain and serum by 39 and 40%, respectively, compared with control diet. Microgliosis and astrocytosis in the brain of Alzheimer’s mice were also reduced by 38 and 35%, respectively. The (−)epicatechin diet did not alter learning and memory behaviors in AD mice. Conclusion: This study has provided evidence on the beneficial role of (−)epicatechin in ameliorating amyloid-induced AD-like pathology in AD mice, but the impact of (−)epicatechin on tau pathology is not clear, also the mechanism needs further research. PMID:24847308

Concentrations of the Allelochemical (+/-)-catechin IN Centaurea maculosa soils.

PubMed

Perry, Laura G; Thelen, Giles C; Ridenour, Wendy M; Callaway, Ragan M; Paschke, Mark W; Vivanco, Jorge M

2007-12-01

The phytotoxin (+/-)-catechin has been proposed to mediate invasion and autoinhibition by the Eurasian plant Centaurea maculosa (spotted knapweed). The importance of (+/-)-catechin to C. maculosa ecology depends in part on whether sufficient catechin concentrations occur at appropriate times and locations within C. maculosa soil to influence neighboring plants. Previous research on catechin in C. maculosa soils has yielded conflicting results, with some studies finding high soil catechin concentrations and other, more recent studies finding little or no catechin in field soils. Here, we report the most extensive study of soil catechin concentrations to date. We examined soil catechin concentrations in 402 samples from 11 C. maculosa sites in North America sampled in consecutive months over 1 yr, excluding winter months. One site was sampled on seven dates, another was sampled twice, and the remaining nine sites were each sampled once on a range of sampling dates. Methods used were similar to those with which we previously measured high soil catechin concentrations. We detected catechin only in the site that was sampled on seven dates and only on one sampling date in that site (May 16 2006), but in all samples collected on that date. The mean soil catechin concentration on that date was 0.65 +/- 0.45 (SD) mg g(-1), comparable to previously reported high concentrations. There are a number of possible explanations for the infrequency with which we detected soil catechin in this work compared to previous studies. Differences in results could reflect spatial and temporal variation in catechin exudation or degradation, as we examined different sites in a different year from most previous studies. Also, large quantities of catechin were detected in blanks for two sampling periods in the present study, leading us to discard those data. This contamination suggests that previous reports of high catechin concentrations that did not include blanks should be viewed with caution. Our results suggest that pure catechin is only rarely present in C. maculosa bulk soils. Thus, although catechin may play a role in C. maculosa invasion, the infrequency of soil catechin that we determined in this study suggests that we cannot be as certain of its role as previous reports of high soil catechin concentrations suggested.

Delineating the anti-cytotoxic and anti-genotoxic potentials of catechin hydrate against cadmium toxicity in human peripheral blood lymphocytes.

PubMed

Alshatwi, Ali A; Hasan, Tarique N; Alqahtani, Ali M; Syed, Naveed A; Shafi, Gowhar; Al-Assaf, Abdullah H; Al-Khalifa, Abdulrahmann S

2014-09-01

Catechins (flavan-3-ol) are a type of natural phenol and well-studied antioxidants. Catechin hydrate, also known as taxifolin; is non-mutagenic, low in toxicity compared to other immunomodulator antioxidants. We aimed to determine the potential of catechin hydrate to prevent the cyto-genotoxic effects of cadmium in lymphocytes; demonstrate the immuno-protective activity of catechin hydrate. Our previous study indicated that cadmium is apoptogenic. Lymphocytes were treated with catechin hydrate or cadmium and catechine hydrate combinations (range 0.1-100μM) to determine their effects on cell viability. Lymphocytes treated with 100μM catechin hydrate and 100μM cadmium showed cell viability 70.65±6.92% and 5.69±2.27%, respectively. In our previous study cadmium (10 and 20μM) induced apoptosis in 31.8% and 44.4% of lymphocytes, respectively. However, the percentage of apoptotic cells after treatment with the combination of cadmium and catechin hydrate was not significantly different from that of catechin hydrate (P>0.05). Only 7.3% and 10.5% of the lymphocytes were apoptotic after treatment with 10μM cadmium+10μM catechin hydrate and 20μM cadmium+20μM catechin hydrate, respectively. The anti-geno-cytotoxic and immuno-protective potential of catechin hydrate was also demonstrated by the non-significant expression of apoptosis-related genes after treatment with catechin hydrate. Copyright © 2014 Elsevier B.V. All rights reserved.

Condensed tannins: Preferential substitution at the interflavanoid bond by sulphite ion

Treesearch

L. Yeap Foo; Gerald W. McGraw; Richard W. Hemingway

1983-01-01

The reaction of loblolly pine (Pinus taeda L.) bark tannins with sodium hydrogen sulphite gave sodium epicatechin-(4β)-sulphonate(1) and sodium epicatechin-(4β→8)-epicatechin-(4β)-sulphonate(2) in high yield with only a minor amount of sodium 1-(3,4-dihydroxyphenyl)-2-hydroxy-3-(2,4,6-trihydroxyphenyl)-propane-1-...

Natural product HTP screening for antibacterial (E.coli 0157:H7) and anti-inflammatory agents in (LPS from E. coli O111:B4) activated macrophages and microglial cells; focus on sepsis.

PubMed

Mazzio, Elizabeth A; Li, Nan; Bauer, David; Mendonca, Patricia; Taka, Equar; Darb, Mohammed; Thomas, Leeshawn; Williams, Henry; Soliman, Karam F A

2016-11-15

Acute systemic inflammatory response syndrome arising from infection can lead to multiple organ failure and death, with greater susceptibility occurring in immunocompromised individuals. Moreover, sub-acute chronic inflammation is a contributor to the pathology of diverse degenerative diseases (Parkinson's disease, Alzheimer's disease and arthritis). Given the known limitations in Western medicine to treat a broad range of inflammatory related illness as well as the emergence of antibiotic resistance, there is a renewed interest in complementary and alternative medicines (CAMs) to achieve these means. A high throughput (HTP) screening of >1400 commonly sold natural products (bulk herbs, cooking spices, teas, leaves, supplement components, nutraceutical food components, fruit and vegetables, rinds, seeds, polyphenolics etc.) was conducted to elucidate anti-inflammatory substances in lipopolysaccharide (LPS) (E. coli serotype O111:B4) monocytes: RAW 264.7 macrophages [peripheral], BV-2 microglia [brain]) relative to hydrocortisone, dexamethasone and L-N6-(1Iminoethyl)lysine (L-NIL). HTP evaluation was also carried out for lethal kill curves against E.coli 0157:H7 1x10 6 CFU/mL relative to penicillin. Validation studies were performed to assess cytokine profiling using antibody arrays. Findings were corroborated by independent ELISAs and NO2-/iNOS expression quantified using the Griess Reagent and immunocytochemistry, respectively. For robust screening, we developed an in-vitro efficacy paradigm to ensure anti-inflammatory parameters were observed independent of cytotoxicity. This caution was taken given that many plants exert tumoricidal and anti-inflammatory effects at close range through similar signaling pathways, which could lead to false positives. The data show that activated BV-2 microglia cells (+ LPS 1μg/ml) release >10-fold greater IL-6, MIP1/2, RANTES and nitric oxide (NO2-), where RAW 264.7 macrophages (+ LPS 1μg/ml) produced > 10-fold rise in sTNFR2, MCP-1, IL-6, GCSF, RANTES and NO2-. Data validation studies establish hydrocortisone and dexamethasone as suppressing multiple pro-inflammatory processes, where L-NIL suppressed NO2-, but had no effect on iNOS expression or IL-6. The screening results demonstrate relative few valid hits with anti-inflammatory effects at < 250μg/ml for the following: Bay Leaf (Laurus nobilis), Elecampagne Root (Inula helenium), Tansy (Tanacetum vulgare),Yerba (Eriodictyon californicum) and Centipeda (Centipeda minima), Ashwagandha (Withania somnifera), Feverfew (Tanacetum parthenium), Rosemary (Rosmarinus officinalis), Turmeric Root (Curcuma Longa), Osha Root (Ligusticum porteri), Green Tea (Camellia sinensis) and constituents: cardamonin, apigenin, quercetin, biochanin A, eupatorin, (-)-epigallocatechin gallate (EGCG) and butein. Natural products lethal against [E. coli 0157:H7] where the LC 50 < 100 μg/ml included bioactive silver hydrosol-Argentyn 23, green tea (its constituents EGCG > Polyphenon 60 > (-)-Gallocatechin > Epicatechin > (+)-Catechin), Grapeseed Extract (Vitis vinifera), Chinese Gallnut (its constituents gallic acid > caffeic acid) and gallic acid containing plants such as Babul Chall Bark (Acacia Arabica), Arjun (Terminalia Arjuna) and Bayberry Root Bark (Morella Cerifera). These findings emphasize and validate the previous work of others and identify the most effective CAM anti-inflammatory, antibacterial compounds using these models. Future work will be required to evaluate potential combination strategies for long-term use to prevent chronic inflammation and possibly lower the risk of sepsis in immunocompromised at risk populations.

Singlet Oxygen Reactions with Flavonoids. A Theoretical – Experimental Study

PubMed Central

Morales, Javier; Günther, Germán; Zanocco, Antonio L.; Lemp, Else

2012-01-01

Detection of singlet oxygen emission, λmax = 1270 nm, following laser excitation and steady-state methods were employed to measure the total reaction rate constant, kT, and the reactive reaction rate constant, kr, for the reaction between singlet oxygen and several flavonoids. Values of kT determined in deuterated water, ranging from 2.4×107 M−1s−1 to 13.4×107 M−1s−1, for rutin and morin, respectively, and the values measured for kr, ranging from 2.8×105 M−1s−1 to 65.7×105 M−1s−1 for kaempferol and morin, respectively, being epicatechin and catechin chemically unreactive. These results indicate that all the studied flavonoids are good quenchers of singlet oxygen and could be valuable antioxidants in systems under oxidative stress, in particular if a flavonoid-rich diet was previously consumed. Analysis of the dependence of rate constant values with molecular structure in terms of global descriptors and condensed Fukui functions, resulting from electronic structure calculations, supports the formation of a charge transfer exciplex in all studied reactions. The fraction of exciplex giving reaction products evolves through a hydroperoxide and/or an endoperoxide intermediate produced by singlet oxygen attack on the double bond of the ring C of the flavonoid. PMID:22802966

Singlet oxygen reactions with flavonoids. A theoretical-experimental study.

PubMed

Morales, Javier; Günther, Germán; Zanocco, Antonio L; Lemp, Else

2012-01-01

Detection of singlet oxygen emission, λ(max) = 1270 nm, following laser excitation and steady-state methods were employed to measure the total reaction rate constant, k(T), and the reactive reaction rate constant, k(r), for the reaction between singlet oxygen and several flavonoids. Values of k(T) determined in deuterated water, ranging from 2.4×10(7) M(-1) s(-1) to 13.4×10(7) M(-1) s(-1), for rutin and morin, respectively, and the values measured for k(r), ranging from 2.8×10(5) M(-1) s(-1) to 65.7×10(5) M(-1) s(-1) for kaempferol and morin, respectively, being epicatechin and catechin chemically unreactive. These results indicate that all the studied flavonoids are good quenchers of singlet oxygen and could be valuable antioxidants in systems under oxidative stress, in particular if a flavonoid-rich diet was previously consumed. Analysis of the dependence of rate constant values with molecular structure in terms of global descriptors and condensed Fukui functions, resulting from electronic structure calculations, supports the formation of a charge transfer exciplex in all studied reactions. The fraction of exciplex giving reaction products evolves through a hydroperoxide and/or an endoperoxide intermediate produced by singlet oxygen attack on the double bond of the ring C of the flavonoid.

Effects of cooking methods on phenolic compounds in xoconostle (Opuntia joconostle).

PubMed

Cortez-García, Rosa María; Ortiz-Moreno, Alicia; Zepeda-Vallejo, Luis Gerardo; Necoechea-Mondragón, Hugo

2015-03-01

Xoconostle, the acidic cactus pear fruit of Opuntia joconostle of the Cactaceae family, is the source of several phytochemicals, such as betalain pigments and numerous phenolic compounds. The aim of the present study was to analyze the effect of four cooking procedures (i.e., boiling, grilling, steaming and microwaving) on the total phenolic content (TPC) and antioxidant activity (measured by ABTS, DPPH, reducing power, and BCBA) of xoconostle. In addition, HPLC-DAD analyses were performed to identify and quantify individual phenolic compounds. After microwaving and steaming xoconostle, the TPC remained the same that in fresh samples, whereas both grilling and boiling produced a significant, 20% reduction (p ≤ 0.05). Total flavonoids remained unchanged in boiled and grilled xoconostle, but steaming and microwaving increased the flavonoid content by 13 and 20%, respectively. Steaming and microwaving did not produce significant changes in the antioxidant activity of xoconostle, whereas boiling and grilling result in significant decreases. The phenolic acids identified in xoconostle fruits were gallic, vanillic, 4-hydroxybenzoic, syringic, ferulic and protocatechuic acids; the flavonoids identified were epicatechin, catechin, rutin, quercitrin, quercetin and kaempferol. Based on the results, steaming and microwaving are the most suitable methods for retaining the highest level of phenolic compounds and flavonoids in xoconostle.

Inhibition of Ca2+-activated Cl- channels by gallotannins as a possible molecular basis for health benefits of red wine and green tea.

PubMed

Namkung, Wan; Thiagarajah, Jay R; Phuan, Puay-Wah; Verkman, A S

2010-11-01

TMEM16A was found recently to be a calcium-activated Cl(-) channel (CaCC). CaCCs perform important functions in cell physiology, including regulation of epithelial secretion, cardiac and neuronal excitability, and smooth muscle contraction. CaCC modulators are of potential utility for treatment of hypertension, diarrhea, and cystic fibrosis. Screening of drug and natural product collections identified tannic acid as an inhibitor of TMEM16A, with IC(50) ∼ 6 μM and ∼100% inhibition at higher concentrations. Tannic acid inhibited CaCCs in multiple cell types but did not affect CFTR Cl(-) channels. Structure-activity analysis indicated the requirement of gallic or digallic acid substituents on a macromolecular scaffold (gallotannins), as are present in green tea and red wine. Other polyphenolic components of teas and wines, including epicatechin, catechin, and malvidin-3-glucoside, poorly inhibited CaCCs. Remarkably, a 1000-fold dilution of red wine and 100-fold dilution of green tea inhibited CaCCs by >50%. Tannic acid, red wine, and green tea inhibited arterial smooth muscle contraction and intestinal Cl(-) secretion. Gallotannins are thus potent CaCC inhibitors whose biological activity provides a potential molecular basis for the cardioprotective and antisecretory benefits of red wine and green tea.

Cardioprotective effects of cocoa: clinical evidence from randomized clinical intervention trials in humans.

PubMed

Arranz, Sara; Valderas-Martinez, Palmira; Chiva-Blanch, Gemma; Casas, Rosa; Urpi-Sarda, Mireia; Lamuela-Raventos, Rosa M; Estruch, Ramon

2013-06-01

Cocoa is an important source of polyphenols, which comprise 12-18% of its total dry weight. The major phenolic compounds in cocoa and cocoa products are mainly flavonoids such as epicatechin, catechin, and proanthocyanidins. These products contain higher amounts of flavonoids than other polyphenol-rich foods. However, the bioavailability of these compounds depends on other food constituents and their interactions with the food matrix. Many epidemiological and clinical intervention trials have concluded that the ingestion of flavonoids reduces the risk factors of developing cardiovascular disease. This review summarizes the new findings regarding the effects of cocoa and chocolate consumption on cardiovascular risk factors. The mechanisms involved in the cardioprotective effects of cocoa flavonoids include reduction of oxidative stress, inhibition of low-density lipoproteins oxidation and platelet aggregation, vasodilatation of blood vessels, inhibition of the adherence of monocytes to vascular endothelium, promotion of fibrinolysis, and immunomodulatory and anti-inflammatory activity. Scientific evidence supports a cause and effect relationship between consumption of cocoa flavonoids and the maintenance of normal endothelium-dependent vasodilation, which contributes to normal blood flow. However, larger randomized trials are required to definitively establish the impact of cocoa and cocoa products consumption on hard cardiovascular outcomes. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Variation in proanthocyanidin content and composition among commonly grown North American cranberry cultivars (Vaccinium macrocarpon).

PubMed

Carpenter, Jessica L; Caruso, Frank L; Tata, Anuradha; Vorsa, Nicholi; Neto, Catherine C

2014-10-01

Cranberry fruit (Vaccinium macrocarpon) is rich in polyphenols, particularly oligomeric proanthocyanidins (PACs) possessing antimicrobial and antioxidant properties. PACs may play a role in resistance to fruit rot. Although many cranberry cultivars are grown for use in foods, beverages and nutraceuticals, data on PAC content among cultivars is limited. Eight cultivars were sampled from four growing regions during the 2010 season and analyzed for PAC content and composition. MALDI-TOF MS showed that isolated PACs had similar oligomer profiles among cultivars. The major constituents were A-type (epi)catechin oligomers of two to eight degrees of polymerization. Total PAC content ranged between 18 and 92 g PAC kg⁻¹ dried fruit, quantified as procyanidin A2 by the dimethylaminocinnamaldehyde method. Among the cultivars sampled, Howes had the highest total PACs (76-92 g kg⁻¹), followed by Mullica Queen and Early Black (48-82 g kg⁻¹). Ben Lear, a disease-susceptible variety, was significantly lower in PACs than the other cultivars (P < 0.001). Several traditional and newer cultivars of cranberry from various growing regions in North America are excellent sources of PACs, particularly the Howes, Mullica Queen and Early Black cultivars. PAC content may play a role in keeping quality. © 2014 Society of Chemical Industry.

The chemistry of wine polyphenolic C-glycosidic ellagitannins targeting human topoisomerase II.

PubMed

Quideau, Stéphane; Jourdes, Michael; Lefeuvre, Dorothée; Montaudon, Danièle; Saucier, Cédric; Glories, Yves; Pardon, Patrick; Pourquier, Philippe

2005-11-04

Polyphenolic nonahydroxyterphenoyl-containing C-glycosidic oak ellagitannins are found in wine as a result of the aging of this beverage in oak-made barrels. Once in the slightly acidic wine (pH approximately 3-4), some of these complex natural products such as (-)-vescalagin (1), but not its C-1 epimer (-)-castalagin (2), can capture grape-derived nucleophilic entities such as ethanol, the flavanols catechin (10a) and epicatechin (10b), the anthocyanin oenin (13b), and the thiolic glutathione (16) to furnish condensation products with retention of configuration at the C-1 locus. A computer-aided rationale of this high diastereoselectivity is given. These condensation products can contribute to the modulation of organoleptic properties of the wine, as evidenced by the 23 nm bathochromic shift color absorbance observed with the novel oenin-based anthocyano-ellagitannin (15b). Hydrolysis of 1 under solvolytic conditions furnished another novel compound that we refer to as vescalene (21), in addition to the known (-)-vescalin (18). Of pharmacological importance is the fact that most of these found-in-wine water-soluble ellagitannin derivatives are much more potent than etoposide (VP-16) at inhibiting top2-mediated DNA decatenation in vitro (top2=topoisomerase II)). The known (-)-vescalin (18) and the novel vescalene (21) fully inhibited top2 at 10 microM concentration!

The Photostabilizing Effect of Grape Seed Extract on Three Common Sunscreen Absorbers.

PubMed

Martincigh, Bice S; Ollengo, Moses A

2016-11-01

The photostabilizing ability of grape seed extract on three common sunscreen absorbers, 2-ethylhexyl-p-methoxycinnamate (EHMC), benzophenone-3 (BP3) and tert-butylmethoxy dibenzoylmethane (BMDBM), was investigated. Samples were exposed to simulated solar radiation and monitored by spectrophotometric and chromatographic methods. The chemical composition of the grape seed extract was determined by GC-MS and HPLC-MS, and the major secondary metabolites were found to be epicatechin and catechin. Exposure of the extract to UV radiation increased the UV absorption capacity of the extract. All sunscreens showed an improved photostability in the extract. The inherent photo-instability of BMDBM when exposed to UV radiation was almost eliminated in the presence of grape seed extract. A mixture of all three sunscreens in the extract showed very high photostability and a red shift covering the entire UVB and UVA regions, thereby improving the broad-spectrum protection. The incorporation of grape seed extract in sunscreen and other cosmetic formulations for topical application boosts photoprotection by stabilizing the UV filters and enhancing broad-spectrum coverage. This in turn helps in reducing the amounts of absorbers and other additives incorporated in a sunscreen product and consequently lowers the risk of an unprecedented buildup of photoproducts whose toxicities are currently unknown. © 2016 The American Society of Photobiology.

Cross-reactivity of antibodies with phenolic compounds in pistachios during quantification of ochratoxin A by commercial enzyme-linked immunosorbent assay kits.

PubMed

Lee, Hyun Jung; Meldrum, Alexander D; Rivera, Nicholas; Ryu, Dojin

2014-10-01

Ochratoxin A (OTA), a nephrotoxic mycotoxin, naturally occurs in wide range of agricultural commodities. Typical screening of OTA involves various enzyme-linked immunosorbent assay (ELISA) methods. Pistachio (Pistacia vera L.) is a rich source of phenolic compounds that may result in a false positive due to structural similarities to OTA. The present study investigated the cross-reactivity profiles of phenolic compounds using two commercial ELISA test kits. High-performance liquid chromatography was used to confirm the concentration of OTA in the pistachio samples and compared with the results obtained from ELISA. When the degree of interaction and 50 % inhibitory concentration of phenolic compounds were determined, the cross-reactivity showed a pattern similar to that observed with the commercial ELSIA kits, although quantitatively different. In addition, the degree of interaction increased with the increasing concentration of phenolic compounds. The ELISA value had stronger correlations with the content of total phenolic compound, gallic acid, and catechin (R(2) = 0.757, 0.732, and 0.729, respectively) compared with epicatechin (R(2) = 0.590). These results suggest that phenolic compounds in pistachio skins may cross-react with the OTA antibody and lead to a false positive or to an overestimation of OTA concentration in ELISA-based tests.

Effect of polyphenols from coffee and grape on gene expression in myoblasts.

PubMed

Priftis, Alexandros; Goutzourelas, Nikolaos; Halabalaki, Maria; Ntasi, Georgia; Stagos, Dimitrios; Amoutzias, Grigorios D; Skaltsounis, Leandros A; Kouretas, Dimitrios

2018-06-01

Coffee and grape contain various bioactive compounds like polyphenols that may exert beneficial effects, especially antioxidant activity, on human health upon consumption. However, the molecular mechanisms through which these effects are achieved are not fully elucidated. Thus, in the present study in order to investigate these mechanisms, a whole genome expression DNA microarray analysis was carried out in myoblasts treated with polyphenols of coffee and grape pomace at concentrations that improved the redox status. Grape was composed of catechin, epicatechin, cyanidin, malvidin, delphinidin, petunidin, myrtillin, kuromanin, oenin, peonidin, quercetin, gallic acid and caftaric acid as LC-MS revealed, with a total polyphenolic content (TPC) of 648 mg of gallic acid equivalents/g of dry matter. Coffee had a TPC of 42.61 mg GAE/g coffee and was composed of 3-chlorogenic acid (16.61 mg/g), 4- and 5-chlorogenic acids (13.62 mg/g), as UHPLC-HRMS revealed. According to the results, grape polyphenols altered mainly the expression of cytoskeleton and differentiation-associated genes, while coffee compounds had a more profound effect, on the expression levels of many metabolic and antioxidant genes possibly through the nuclear factor (erythroid-derived 2) like-2 (Nrf2) pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhibitory effect of hot-water extract from dried fruit of Crataegus pinnatifida on low-density lipoprotein (LDL) oxidation in cell and cell-free systems.

PubMed

Chu, Chia-Yih; Lee, Miao-Jane; Liao, Chuen-Lan; Lin, Wea-Lung; Yin, Yu-Fang; Tseng, Tsui-Hwa

2003-12-17

The dried fruit of Crataegus pinnatifida, a local soft drink material and medical herb, was found to possess potential against oxidative stress. In the preliminary study, the antioxidant potential of a hot-water extract obtained from the dried fruit of C. pinnatifida (CF-H) was evaluated in terms of its capacity of quenching 1,1-diphenyl-2-picrylhydrazyl free radicals (EC(50) = 0.118 mg/mL). After content analysis, it was found that CF-H is mainly composed of polyphenols including flavonoids (6.9%), procyanidins (2.2%), (+)-catechin (0.5%), and (-)-epicatechin (0.2%). The antioxidative bioactivity of CF-H had been assess previously using the models of CuSO(4) as cell-free system and sodium nitroprusside (SNP) plus macrophage RAW 264.7 cells as cell system to induce human low-density lipoprotein oxidation. CF-H was found to inhibit relative electrophoretic mobility and thiobarbituric acid reactive substances at the concentration of 0.5-1.0 mg/mL in the cell-free system and at 0.01-0.10 mg/mL in the cell system. Furthermore, it was found that CF-H decreased the SNP-induced cell lipid peroxidation and reduced glutathione depletion.

Assessment of antibacterial properties and the active ingredient of plant extracts and its effect on the performance of crucian carp (Carassius auratus gibelio var. E'erqisi, Bloch).

PubMed

Lu, Chunxia; Luo, Xiaoling; Luo, Ruifeng; Chen, Xia; Xing, Lijie; Tang, Zonggui; Li, Hongmin

2013-03-15

In this study, the antibacterial properties and active ingredient of plant extracts and its effect on the performance of crucian carp (Carassius auratus gibelio var. E'erqisi, Bloch) were assessed. The transmission electron microscopy and flow cytometric analysis showed that the antibacterial activity of plant extracts is due to the disruption of the cell membrane and the leakage of cytoplasmic contents. The UPLC-MS/MS analysis showed that the contents of gallic acid, (-)-epigallocatechin, (+)-catechin, (-)-epigallocatechin gallate, (-)-epicatechin gallate, aloe-emodin, rhein, emodin, chrysophanol, and physcion, were 5.27%, 3.30%, 1.08%, 19.32%, 5.46%, 0.23%, 0.56%, 1.28%, 0.75% and 0.39% in plant extracts, respectively. Results of feeding experiment showed that feeding crucian carp with 1.0% and 2.0% plant extracts significantly enhanced specific growth rate, serum total protein, lysozyme, catalase and superoxide dismutase activities, and decreased the feed conversion rate, malondialdehyde contents and the mortality rate (P < 0.05). It can be concluded that plant extracts added to fish feed can act as natural antimicrobial and immunostimulants to prevent pathogenic infection, enhance immune response, and promote growth of the fish. © 2012 Society of Chemical Industry.

Separation of polyphenols and arecoline from areca nut (Areca catechu L.) by solvent extraction, its antioxidant activity, and identification of polyphenols.

PubMed

Chavan, Yogita V; Singhal, Rekha S

2013-08-15

Areca nut (Areca catechu L.) or betel nut, a commercial cash crop, is a rich source of polyphenols but also contains toxic alkaloids, mainly arecoline. Separation of these bioactive polyphenols from toxic constituents could propel the safe and beneficial use of betel nut; also it will help arecanut processing industries to produce arecoline-free products. With the aim to develop an effective method for maximum extraction of polyphenols with minimum arecoline, several factors such as nature of the solvent, pH (2-10), substrate concentration (6-14 %) and extraction time (30-150 min) under shaking conditions were evaluated. Qualitative analysis was done using spectrophotometry and high-performance liquid chromatography (HPLC). Maximum extraction of polyphenols (407.47 mg GAE g(-1)), total tannin and its antioxidant activity with minimum arecoline (1.73 mg g(-1) of sample) was achieved by using 80% acetone at pH 4 for 90 min with 10% w/v substrate under shaking conditions. Solvent extraction under optimized parameters gave maximum polyphenols with minimum extraction of arecoline, and highest ratio of polyphenols to arecoline. HPLC and liquid chromatography-mass spectrometry results confirmed the presence of catechin and epicatechin in the extract, which suggests its potential as a source of bioactives. © 2013 Society of Chemical Industry.

Antioxidant and protective effect of inulin and catechin grafted inulin against CCl4-induced liver injury.

PubMed

Liu, Jun; Lu, Jian-feng; Wen, Xiao-yuan; Kan, Juan; Jin, Chang-hai

2015-01-01

In this study, the antioxidant activity and hepatoprotective effect of inulin and catechin grafted inulin (catechin-g-inulin) against carbon tetrachloride (CCl4)-induced acute liver injury were investigated. Results showed that both inulin and catechin-g-inulin had moderate scavenging activity on superoxide radical, hydroxyl radical and H2O2, as well as lipid peroxidation inhibition effect. The antioxidant activity decreased in the order of Vc > catechin >catechin-g-inulin > inulin. Administration of inulin and catechin-g-inulin could significantly reduce the elevated levels of serum aspartate transaminase, alanine transaminase and alkaline phosphatase as compared to CCl4 treatment group. Moreover, inulin and catechin-g-inulin significantly increased the levels of hepatic superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione and total antioxidant capacity, whereas markedly decreased the malondialdehyde level when compared with CCl4 treatment group. Notably, catechin-g-inulin showed higher hepatoprotective effect than inulin. In addition, the hepatoprotective effect of catechin-g-inulin was comparable to positive standard of silymarin. Our results suggested that catechin-g-inulin had potent antioxidant activity and potential protective effect against CCl4-induced acute liver injury. Copyright © 2014 Elsevier B.V. All rights reserved.

A dose-response effect from chocolate consumption on plasma epicatechin and oxidative damage.

PubMed

Wang, J F; Schramm, D D; Holt, R R; Ensunsa, J L; Fraga, C G; Schmitz, H H; Keen, C L

2000-08-01

Evidence from epidemiological studies suggests that a diet high in plant foods and rich in polyphenols is inversely associated with a risk for cardiovascular and other chronic diseases. Chocolate, like red wine and green tea, is a polyphenol-rich food, primarily containing procyanidin polyphenols. These polyphenols are hypothesized to provide cardioprotective effects due to their ability to scavenge free radicals and inhibit lipid oxidation. Herein, we demonstrate that 2 h after the ingestion of a procyanidin-rich chocolate containing 5.3 mg total procyanidin/g, of which 1.3 mg/g was (-)-epicatechin (epicatechin), plasma levels of epicatechin increased 133 +/- 27, 258 +/- 29 and 355 +/- 49 nmol/L in individuals who consumed 27, 53 and 80 g of chocolate, respectively. That the rise in plasma epicatechin levels was functionally significant is suggested by observations of trends for dose-response increases in the plasma antioxidant capacity and decreases in plasma lipid oxidation products. The above data support the theories that in healthy adults, 1) a positive relationship exists between procyanidin consumption and plasma procyanidin concentration and 2) the rise in plasma epicatechin contributes to the ability of plasma to scavenge free radicals and to inhibit lipid peroxidation.

Aqueous extract from pecan nut [Carya illinoinensis (Wangenh) C. Koch] shell show activity against breast cancer cell line MCF-7 and Ehrlich ascites tumor in Balb-C mice.

PubMed

Hilbig, Josiane; Policarpi, Priscila de Britto; Grinevicius, Valdelúcia Maria Alves de Souza; Mota, Nádia Sandrine Ramos Santos; Toaldo, Isabela Maia; Luiz, Marilde Terezinha Bordignon; Pedrosa, Rozangela Curi; Block, Jane Mara

2018-01-30

In Brazil many health disorders are treated with the consumption of different varieties of tea. Shell extracts of pecan nut (Carya illinoinensis), which have significant amounts of phenolic compounds in their composition, are popularly taken as tea to prevent diverse pathologies. Phenolic compounds from pecan nut shell extract have been associated with diverse biological effects but the effect on tumor cells has not been reported yet. The aim of the current work was to evaluate the relationship between DNA fragmentation, cell cycle arrest and apoptosis induced by pecan nut shell extract and its antitumor activity. Cytotoxicity, proliferation, cell death and cell cycle were evaluated in MCF-7 cells by MTT, colony assay, differential coloring and flow cytometry assays, respectively. DNA damage effects were evaluated through intercalation into CT-DNA and plasmid DNA cleavage. Tumor growth inhibition, survival time increase, apoptosis and cell cycle arrest were assessed in Ehrlich ascites tumor in Balb/C mice. The cytotoxic effect of pecan nut shell extracts, the induction of cell death by apoptosis and also the cell cycle arrest in MCF-7 cells have been demonstrated. The survival time in mice with Ehrlich ascites tumor increased by 67%. DNA damage was observed in the CT-DNA, plasmid DNA and comet assays. The mechanism involved in the antitumor effect of pecan nut shell extracts may be related to the activation of key proteins involved in apoptosis cell death (Bcl-XL, Bax and p53) and on the cell cycle regulation (cyclin A, cyclin B and CDK2). These results were attributed to the phenolic profile of the extract, which presented compounds such as gallic, 4-hydroxybenzoic, chlorogenic, vanillic, caffeic and ellagic acid, and catechin, epicatechin, epigallocatechin and epicatechin gallate. The results indicated that pecan nut shell extracts are effective against tumor cells growth and may be considered as an alternative to the treatment of cancer. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Changes in the structural and gel properties of pork myofibrillar protein induced by catechin modification.

PubMed

Jia, Na; Wang, Letian; Shao, Junhua; Liu, Dengyong; Kong, Baohua

2017-05-01

Different concentrations of catechin (0, 10, 50, 100 and 200μmol/g protein) were added to pork myofibrillar protein (MP) suspensions, and the related changes in protein conformational and gel properties were investigated. The results showed that catechin at 200μmol/g protein led to the greatest increase in the surface hydrophobicity of MP. A significant loss of thiols (SH) content was observed in MP in the presence of catechin. The low concentration of catechin of 10μmol/g led to slight changes in the MP gel strength and water-holding capacity. However, catechin at higher concentrations (50, 100 and 200μmol/g protein) caused severe deterioration of MP gelation. The microstructure and dynamic rheological properties confirmed the unfavorable effect of catechin on the MP gel properties. The results indicate that catechin caused changes in MP conformational and gel properties, which may be due to the catechin-MP covalent interactions and the exposure of hydrophobic domains caused by catechin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Catechin is a phytotoxin and a pro-oxidant secreted from the roots of Centaurea stoebe

PubMed Central

Kaushik, Shail; Biedrzycki, Meredith L; Venkatachalam, Lakshmannan

2010-01-01

When applied to the roots of Arabidopsis thaliana, the phytotoxin (±)-catechin triggers a wave of reactive oxygen species (ROS), leading to a cascade of genome-wide changes in gene expression and, ultimately, death of the root system. Biochemical links describing the root secreted phytotoxin, (±)-catechin, represent one of most well studied systems to describe biochemically based negative plant-plant interactions, but of late have also sparked controversies on phytotoxicity and pro-oxidant behavior of (±)-catechin. The studies originating from two labs1–3 maintained that (±)-catechin is not at all phytotoxic but has strong antioxidant activity. The step-wise experiments performed and the highly correlative results reported in the present study clearly indicate that (±)-catechin indeed is phytotoxic against A. thaliana and Festuca idahoensis. Our results show that catechin dissolved in both organic and aqueous phase inflicts phytotoxic activity against both A. thaliana and F. idahoensis. We show that the deviation in results highlighted by the two labs1–3 could be due to different media conditions and a group effect in catechin treated seedlings. We also determined the presence of catechin in the growth medium of C. stoebe to support the previous studies. One of the largest functional categories observed for catechin-responsive genes corresponded to gene families known to participate in cell death and oxidative stress. Our results showed that (±)-catechin treatment to A. thaliana plants resulted in activation of signature cell death genes such as accelerated cell death (acd2) and constitutively activated cell death 1 (cad1). Further, we confirmed our earlier observation of (±)-catechin induced ROS mediated phytotoxicity in A. thaliana. We also provide evidence that (±)-catechin induced ROS could be aggravated in the presence of divalent transition metals. These observations have significant impact on our understanding regarding catechin phytotoxicity and pro-oxidant activity. Our data also illustrates that precise conditions are needed to evaluate the effect of catechin phytotoxicity. PMID:20505358

Stimulation or Inhibition: Conflicting evidence for (+/-)-catechin's role as a chemical facilitator and disease protecting agent.

PubMed

Bais, Harsh P; Venkatachalam, L; Biedrzycki, Meredith L

2010-03-01

The occurrence of plant hormesis is a poorly understood phenomenon, wherein low doses of phytotoxins unusually promote growth responses in higher plants. In contrast, negative plant-plant interactions mediated through secreted small molecular weight compounds initiate growth inhibitory responses. Studies related to (+/-)-catechin mediated allelopathy have transpired both novel information and generated significant controversy. Specifically, studies related to the phytotoxicity responses mediated by (+/-)-catechins have been seriously debated. The pronged opinion that (+/-)-catechin is phytotoxic versus non-phytotoxic relies more on the target plant systems and the conditions used to test phytotoxic responses. It is reported that lower than MIC dosage supplementation of (+/-)-catechin could promote growth responses in the model plant Arabidopsis thaliana. Furthermore, it was shown that sub-MIC levels of (+/-)-catechin supplementation leads to elicitation of disease resistance against Pseudomonas syringae DC3000 (hereafter DC3000). Intrigued by the unique hormesis response observed, we tested whether (+/-)-catechin indeed promotes growth responses in A. thaliana. In our hands, we observed no growth promotion responses of (+/-)-catechin against A. thaliana under in vitro or in soil conditions. We also evaluated the previously reported disease protecting properties of (+/-)-catechin in A. thaliana against DC3000. The systematic observations to evaluate disease protecting properties entailing colony counts, disease incidences and loss of chlorophyll studies showed no disease protecting properties of (+/-)-catechin. The transcriptional response for a marker pathogenesis related PR1 defense gene showed no induction post (+/-)-catechin supplementation. The cell death genes (ACD2 and CAD1) associated with programmed cell death revealed unchanged expression levels in plants treated with sub-MIC levels of (+/-)-catechin. Further, we report supplementation of sub-MIC levels of (+/-)-catechin negates any change in the expression of an auxin responsive gene. Our results refute the previous claims of growth and defense inducing effects of (+/-)-catechin, thus suggesting that a thorough reexamination is required to evaluate the hormetic effect of (+/-)-catechin under both controlled and natural conditions.

[Morphologic studies of the protective role of catechin on kanamycin otoneurotoxicity in SD rats].

PubMed

Liu, Guo-hui; Xie, Ding-hua; Wu, Wei-jing

2002-12-28

To determine the protection of catechin on aminoglycoside antibiotics otoneurotoxicity in SD rats, and observe the morphologic changes of cochlear efferent nerve terminals and outer hair cells after the injection of kanamycin and the feeding of catechin by the stomach tube. Thirty-eight SD rats were randomly assigned into three experimental groups (KM-treated, catechin-treated, KM and catechin in combination) and one control group. The KM-treated group was given kanamycin in a dose of 500 mg.(kg.d)-1 for 14 days. The catechin-treated group was given catechin once by the stomach tube in a dose of 400 mg.(kg.d)-1. Two kinds of medicine were simultaneously given in the KM+ catechin group. Transmission electron microscopy was utilized to observe the subcellular structure of efferent nerve fibers and outer hair cells. The densities of efferent nerve fibers and terminals were examined and the numbers of efferent nerve fibers and terminals were numerated by the surface preparation using modified histochemical staining for acetylcholinesterase (AchE). The damage in the group protected by catechin was relieved compared with the unprotected group. No damage was found in the catechin-treated alone group and controls. The densities and numbers of efferent nerve fibers and terminals were obviously fewer in the unprotected group than in the protected group and controls(P < 0.05). There was no significant difference in the numbers of efferent nerve fibers and terminals of the group protected by catechin compared with the controls and the catechin-treated group (P > 0.05). Catechin significantly protects MOC efferent nerves in kanamycin otoneurotoxicity.

(+/-)-catechin: chemical weapon, antioxidant, or stress regulator?

PubMed

Chobot, Vladimir; Huber, Christoph; Trettenhahn, Guenter; Hadacek, Franz

2009-08-01

(+/-)-Catechin is a flavan-3-ol that occurs in the organs of many plant species, especially fruits. Health-beneficial effects have been studied extensively, and notable toxic effects have not been found. In contrast, (+/-)-catechin has been implicated as a 'chemical weapon' that is exuded by the roots of Centaurea stoebe, an invasive knapweed of northern America. Recently, this hypothesis has been rejected based on (+/-)-catechin's low phytotoxicity, instability at pH levels higher than 5, and poor recovery from soil. In the current study, (+/-)-catechin did not inhibit the development of white and black mustard to an extent that was comparable to the highly phytotoxic juglone, a naphthoquinone that is allegedly responsible for the allelopathy of the walnut tree. At high stress levels, caused by sub-lethal methanol concentrations in the medium, and a 12 h photoperiod, (+/-)-catechin even attenuated growth retardation. A similar effect was observed when (+/-)-catechin was assayed for brine shrimp mortality. Higher concentrations reduced the mortality caused by toxic concentrations of methanol. Further, when (+/-)-catechin was tested in variants of the deoxyribose degradation assay, it was an efficient scavenger of reactive oxygen species (ROS) when they were present in higher concentrations. This antioxidant effect was enhanced when iron was chelated directly by (+/-)-catechin. Conversely, if iron was chelated to EDTA, pro-oxidative effects were demonstrated at higher concentrations; in this case (+/-)-catechin reduced molecular oxygen and iron to reagents required by the Fenton reaction to produce hydroxyl radicals. A comparison of cyclic voltammograms of (+/-)-catechin with the phytotoxic naphthoquinone juglone indicated similar redox-cycling properties for both compounds although juglone required lower electrochemical potentials to enter redox reactions. In buffer solutions, (+/-)-catechin remained stable at pH 3.6 (vacuole) and decomposed at pH 7.4 (cytoplasm) after 24 h. The results support the recent rejection of the hypothesis that (+/-)-catechin may serve as a 'chemical weapon' for invasive plants. Instead, accumulation and exudation of (+/-)-catechin may help plants survive periods of stress.

Using Defatted Rice Bran as a Bioadsorbent for Carrying Tea Catechins.

PubMed

Shi, Meng; Yang, Ya-Ping; Jin, Jing; Huang, Long-Yue; Ye, Jian-Hui; Liang, Yue-Rong

2015-10-01

The potential of rice bran as a bioabsorbent for tea catechins was examined. Defatted rice bran had the highest adsorption capacity for tea catechins and the best selectivity for (-)-epigallocatechin gallate over total catechins among water-washed rice bran and untreated rice bran. The adsorption characteristics of tea catechins onto defatted rice bran were determined over a range of concentration (0.5 to 2.5 g/L) and temperatures (10, 25, and 45 °C). The adsorption of tea catechins onto defatted rice bran showed excellent fitness with the pseudo-second-order model at different temperature. Both the Langmuir and Freundlich models adequately describe the isothermal adsorption of tea catechins onto defatted rice bran. The adsorption of total catechins on rice bran decreased from 10 to 25 °C, whereas was greatly enhanced at 45 °C. The adsorption system of bioadsorbent with multiconstituents may not be as simple as the single-force-driving adsorption system. Protein and cellulose are the main contributors to the adsorption of tea catechins on defatted rice bran. Rice bran is regarded as a good fibre source that can be added to various food products and health supplements, which is a potential biocarrier for bioactives. Our study showed that defatted rice bran had a high affinity for tea catechins but caffeine, and provided a promising way for selective enrichment of catechins on defatted rice bran under practical condition. Protein and cellulose are the main contributors to the adsorption of tea catechins on defatted rice bran. © 2015 Institute of Food Technologists®

Synthesis and structural characterization of oaklin-catechins.

PubMed

Sousa, André; Fernandes, Ana; Mateus, Nuno; De Freitas, Victor

2012-02-15

Condensation reactions of procyanidin dimer B4 with two representative oak wood cinnamic aldehydes (coniferaldehyde and sinapaldehyde) were conducted in winelike model solutions. Coniferaldehyde led to the formation of guaiacylcatechin-pyrylium-catechin (GCP-catechin, 737 m/z), whereas sinapaldehyde led to the formation of syringylcatechin-pyrylium-catechin (SCP-catechin, 767 m/z). The former was also structurally characterized by 1D and 2D NMR, allowing an elucidation of the formation mechanism of these oaklin-catechin adducts and demonstrating the importance of procyanidins in the formation of colored compounds through the reaction with cinnamic aldehydes extracted from oaks during storage.

Evolution of microbiological and chemical parameters during red wine making with extended post-fermentation maceration.

PubMed

Francesca, Nicola; Romano, Raffaele; Sannino, Ciro; Le Grottaglie, Laura; Settanni, Luca; Moschetti, Giancarlo

2014-02-03

The aim of the present work was to investigate the microbiological, chemical, and sensory characteristics of red wine subjected to post-fermentation maceration that was extended to 90 days. For this purpose, the 'Aglianico di Taurasi' grape was used as a case study. The total yeast concentration increased until day 40 of maceration and decreased thereafter, whereas the concentration of lactic acid bacteria slightly increased. Dekkera/Brettanomyces spp. and acetic acid bacteria were not detected. The yeast community was composed of Saccharomyces cerevisiae, Zygosaccharomyces bisporus, Metschnikowia pulcherrima, Hanseniaspora guilliermondii, Hanseniaspora uvarum, Pichia guilliermondii, Aureobasidium pullulans and Debaryomyces carsonii. Nine S. cerevisiae strains were detected at high levels at different times of maceration. The results of all the conventional chemical analyses of the wines were in agreement with the regulations of commercial production and, interestingly, the changes in terms of concentration demonstrated the presence of yeast and LAB populations that were not only alive but also in a metabolically active state until day 90 of maceration. The alcohol and glycerol contents slightly increased until day 90. The concentrations of malic acid decreased, whereas those of lactic acid slightly increased throughout the maceration process. Furthermore, different durations of maceration resulted in significant differences in the total polyphenol content, which was higher at 40-50 days. The main phenolic compounds were benzoic and cinnamic acids and catechins. Interestingly, the highest ratio between (+)-catechin and (-)-epicatechin was found on day 40. In addition, the highest antioxidant activity was observed between days 40 and 50. The concentration of volatile organic compounds, which were mainly represented by alcohols, increased until the end of the maceration process. Sensory analysis revealed that samples that were subjected to maceration for a long period of time showed the highest odour and taste complexity and no off-odours and/or off-flavours were detected. These data confirmed that extending post-fermentation maceration to 90 days has no negative impact on the microbiological, chemical and sensory composition of wines, but affects the polyphenol content and potential health benefits of the resulting wine. Copyright © 2013 Elsevier B.V. All rights reserved.

Investigation of the flavan-3-ol patterns in willow species during one growing-season.

PubMed

Wiesneth, Stefan; Aas, Gregor; Heilmann, Jörg; Jürgenliemk, Guido

2018-01-01

Flavonoids, proanthocyanidins (PAs) and salicylic alcohol derivatives are the main groups of ingredients in Salix needed as defensive tools and signal molecules, but have also pharmaceutical importance. The present study investigated total PA content, complete PA pattern, the oligomeric/total PAs quotient and the contents of catechin and epicatechin during one growing-season for the leaves and this year's sprouts in ten willows (Salix pentandra L. ♂, S. alba L. ♂, S. fragilis L. ♀, S. caprea L. ♂ & ♀, S. cinerea L. ♂, S. caprea x cinerea ♂, S. daphnoidesVill. ♂ & ♀ and S. purpurea L. ♀; all Salicaceae). Comparison of the different species revealed distinct seasonal fluctuations of the oligomeric and polymeric PA fractions, but the contents of both groups always developed in the same direction. All willows prefer the synthesis of PAs with DP-2 - DP-4 within the oligomeric fraction (DP-2 - DP-10) and species with rather low PA contents like S. purpurea (0.1-2.6 mg/g) as well as species with rather high PA contents like S. alba (3.8-14.7 mg/g) were found. Only slight gender specific differences could be observed for both sexes of S. daphnoides and S. caprea. The PA pattern of the hybrid S. caprea x cinerea seems to be influenced by both parents. Thus, the accumulation of the oligomeric PAs accorded to S. caprea and the polymeric PAs matched S. cinerea resulting in an overall depression of PAs in the sprouts and a varying seasonal trend in the leaves. In contrast, the content of catechin remained high and seemed to be not influenced in the hybrid. Although only one individual of each Salix species could be considered in this screening study, the present results demonstrate the variability of the flavan-3-ol pattern within the genus Salix but also some preliminary correlations could be observed. Future studies with more Salix species will provide more insights into chemotaxonomic correlations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Detection of the antiviral activity of epicatechin isolated from Salacia crassifolia (Celastraceae) against Mayaro virus based on protein C homology modelling and virtual screening.

PubMed

Ferreira, P G; Ferraz, A C; Figueiredo, J E; Lima, C F; Rodrigues, V G; Taranto, A G; Ferreira, J M S; Brandão, G C; Vieira-Filho, S A; Duarte, L P; de Brito Magalhães, C L; de Magalhães, J C

2018-06-01

Mayaro fever, caused by Mayaro virus (MAYV) is a sub-lethal disease with symptoms that are easily confused with those of dengue fever, except for polyarthralgia, which may culminate in physical incapacitation. Recently, outbreaks of MAYV have been documented in metropolitan areas, and to date, there is no therapy or vaccine available. Moreover, there is no information regarding the three-dimensional structure of the viral proteins of MAYV, which is important in the search for antivirals. In this work, we constructed a three-dimensional model of protein C of MAYV by homology modelling, and this was employed in a manner similar to that of receptors in virtual screening studies to evaluate 590 molecules as prospective antiviral agents. In vitro bioassays were utilized to confirm the potential antiviral activity of the flavonoid epicatechin isolated from Salacia crassifolia (Celastraceae). The virtual screening showed that six flavonoids were promising ligands for protein C. The bioassays showed potent antiviral action of epicatechin, which protected the cells from almost all of the effects of viral infection. An effective concentration (EC 50 ) of 0.247 μmol/mL was observed with a selectivity index (SI) of 7. The cytotoxicity assay showed that epicatechin has low toxicity, with a 50% cytotoxic concentration (CC 50 ) greater than 1.723 µmol/mL. Epicatechin was found to be twice as potent as the reference antiviral ribavirin. Furthermore, a replication kinetics assay showed a strong inhibitory effect of epicatechin on MAYV growth, with a reduction of at least four logs in virus production. Our results indicate that epicatechin is a promising candidate for further testing as an antiviral agent against Mayaro virus and other alphaviruses.

Enzymatic lipophilization of epicatechin with free fatty acids and its effect on antioxidative capacity in crude camellia seed oil.

PubMed

Chen, Sa-Sa; Luo, Shui-Zhong; Zheng, Zhi; Zhao, Yan-Yan; Pang, Min; Jiang, Shao-Tong

2017-02-01

Crude camellia seed oil is rich in free fatty acids, which must be removed to produce an oil of acceptable quality. In the present study, we reduced the free fatty acid content of crude camellia seed oil by lipophilization of epicatechin with these free fatty acids in the presence of Candida antarctica lipase B (Novozym 435), and this may enhance the oxidative stability of the oil at the same time. The acid value of crude camellia seed oil reduced from 3.7 to 2.5 mgKOH g -1 after lipophilization. Gas chomatography-mass spectrometry analysis revealed that epicatechin oleate and epicatechin palmitate were synthesized in the lipophilized oil. The peroxide, p-anisidine, and total oxidation values during heating of the lipophilized oil were much lower than that of the crude oil and commercially available camellia seed oil, suggesting that lipophilized epicatechin derivatives could help enhance the oxidative stability of edible oil. The enzymatic process to lipophilize epicatechin with the free fatty acids in crude camellia seed oil described in the present study could decrease the acid value to meet the quality standards for commercial camellia seed oil and, at the same time, obtain a new edible camellia seed oil product with good oxidative stability. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Stimulation or Inhibition Conflicting evidence for (±)-catechin’s role as a chemical facilitator and disease protecting agent

PubMed Central

Venkatachalam, L; Biedrzycki, Meredith L

2010-01-01

The occurrence of plant hormesis is a poorly understood phenomenon, wherein low doses of phytotoxins unusually promote growth responses in higher plants. In contrast, negative plant-plant interactions mediated through secreted small molecular weight compounds initiate growth inhibitory responses. Studies related to (±)-catechin mediated allelopathy have transpired both novel information and generated significant controversy. Specifically, studies related to the phytotoxicity responses mediated by (±)-catechins have been seriously debated. The pronged opinion that (±)-catechin is phytotoxic versus non-phytotoxic relies more on the target plant systems and the conditions used to test phytotoxic responses. It is reported that lower than MIC dosage supplementation of (±)-catechin could promote growth responses in the model plant Arabidopsis thaliana. Furthermore, it was shown that sub-MIC levels of (±)-catechin supplementation leads to elicitation of disease resistance against Pseudomonas syringae DC3000 (hereafter DC3000). Intrigued by the unique hormesis response observed, we tested whether (±)-catechin indeed promotes growth responses in A. thaliana. In our hands, we observed no growth promotion responses of (±)-catechin against A. thaliana under in vitro or in soil conditions. We also evaluated the previously reported disease protecting properties of (±)-catechin in A. thaliana against DC3000. The systematic observations to evaluate disease protecting properties entailing colony counts, disease incidences and loss of chlorophyll studies showed no disease protecting properties of (±)-catechin. The transcriptional response for a marker pathogenesis related PR1 defense gene showed no induction post (±)-catechin supplementation. The cell death genes (AC D2 and CA D1) associated with programmed cell death revealed unchanged expression levels in plants treated with sub-MIC levels of (±)-catechin. Further, we report supplementation of sub-MIC levels of (±)-catechin negates any change in the expression of an auxin responsive gene. Our results refute the previous claims of growth and defense inducing effects of (±)-catechin, thus suggesting that a thorough reexamination is required to evaluate the hormetic effect of (±)-catechin under both controlled and natural conditions. PMID:20023372

Catechin prodrugs and analogs: a new array of chemical entities with improved pharmacological and pharmacokinetic properties.

PubMed

Bansal, Sumit; Vyas, Sandeep; Bhattacharya, Shoumyo; Sharma, Manu

2013-10-11

Extensive research on tea catechins, mainly (-)-epigallocatechin gallate, has shown numerous health promoting effects. However, various clinical studies demonstrated several issues associated with tea catechins which account for their poor systemic bioavailability. In order to improve pharmacological activity and bioavailability of natural tea catechins, two major strategies have been adopted to date which include synthesizing catechin analogs/prodrugs and the development of novel drug delivery systems. In this review, we provide a detailed account of novel synthetic analogs/prodrugs as well as novel drug delivery approaches used for natural tea catechins to make them therapeutically potent drug-like molecules.

Using tea stalk lignocellulose as an adsorbent for separating decaffeinated tea catechins.

PubMed

Ye, J H; Jin, J; Liang, H L; Lu, J L; Du, Y Y; Zheng, X Q; Liang, Y R

2009-01-01

Lignocelluloses prepared from woody tea stalk, pine sawdust and sugarcane bagasse were used as adsorbents to isolate decaffeinated catechins from tea extracts and compared with synthetic macroporous resin HPD 600. HPD 600 had the highest adsorption capacity to catechins, followed by tea stalk lignocellulose while lignocelluloses of pine sawdust and bagasse the least. Tea stalk lignocellulose absorbed preferentially tea catechins and showed a good selectivity. HPD 600 absorbed caffeine and tea catechins simultaneously. The kinetics data of tea stalk lignocellulose showed a good fit with the Langmuir isotherm model. It is considered that tea stalk lignocellulose is an alternative low-cost adsorbent for preparing decaffeinated tea catechins.

Catechin secretion and phytotoxicity: Fact not fiction.

PubMed

Bais, Harsh P; Kaushik, Shail

2010-09-01

Research indicates that the invasiveness of Centaurea stoebe is attributed to the stronger allelopathic effects on the native North American species than on the related European species, which is one of the unquestionable aspects of the "novel weapons hypothesis (NWH)." Studies originating from controlled to field conditions have shown that C. stoebe utilizes its biochemical potential to exert its invasiveness. The roots of C. stoebe secrete a potent phytotoxin, catechin, which has a detrimental effect on the surrounding plant species. Although, studies on catechin secretion and phytotoxicity represent one of the most well studied systems describing negative plant-plant interactions, it has also sparked controversies lately due to its phytotoxicity dosages and secretion effluxes. Previous reports negate the phytotoxic and pro-oxidant nature of catechin.1-3 In our recent study we have shown that catechin is highly phytotoxic against Arabidopsis thaliana and Festuca idahoensis. We also show that (±) catechin applied to roots of A. thaliana induces reactive oxygen species (ROS) confirming the pro-oxidant nature of catechin. In addition, activation of signature cell death genes such as acd2 and cad1 post catechin treatment in A. thaliana ascertains the phytotoxic nature of catechin.

Catechin secretion and phytotoxicity

PubMed Central

Kaushik, Shail

2010-01-01

Research indicates that the invasiveness of Centaurea stoebe is attributed to the stronger allelopathic effects on the native North American species than on the related European species, which is one of the unquestionable aspects of the “novel weapons hypothesis (NWH).” Studies originating from controlled to field conditions have shown that C. stoebe utilizes its biochemical potential to exert its invasiveness. The roots of C. stoebe secrete a potent phytotoxin, catechin, which has a detrimental effect on the surrounding plant species. Although, studies on catechin secretion and phytotoxicity represent one of the most well studied systems describing negative plant-plant interactions, it has also sparked controversies lately due to its phytotoxicity dosages and secretion effluxes. Previous reports negate the phytotoxic and pro-oxidant nature of catechin.1–3 In our recent study we have shown that catechin is highly phytotoxic against Arabidopsis thaliana and Festuca idahoensis. We also show that (±) catechin applied to roots of A. thaliana induces reactive oxygen species (ROS) confirming the pro-oxidant nature of catechin. In addition, activation of signature cell death genes such as acd2 and cad1 post catechin treatment in A. thaliana ascertains the phytotoxic nature of catechin. PMID:21057643

Separation and identification of twelve catechins in tea using liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry.

PubMed

Zeeb, D J; Nelson, B C; Albert, K; Dalluge, J J

2000-10-15

A method has been developed for the direct microscale determination of 12 catechins in green and black tea infusions. The method is based on liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS). Standard catechin mixtures and tea infusions were analyzed by LC/APCI-MS with detection of protonated molecular ions and characteristic fragment ions for each compound. The identities of eight major catechins and caffeine in tea were established based on LC retention times and simultaneously recorded mass spectra. In addition, monitoring of the catechin-specific retro Diels-Alder fragment ion at m/z 139 throughout the chromatogram provided a unique fingerprint for catechin content in the samples that led to the identification of four minor chemically modified catechin derivatives in the infusions. This report is the first to describe the comprehensive determination of all 12 reported catechins in a single analysis. The utility of LC/APCI-MS for providing routine separation and identification of catechins at femtomole to low-picomole levels without extraction or sample pretreatment, and its potential as a standard analytical tool for the determination of polyphenols in natural products and biological fluids, are discussed.

Protective effect of catechin in type I Gaucher disease cells by reducing endoplasmic reticulum stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Yea-Jin; Kim, Sung-Jo, E-mail: sungjo@hoseo.edu; Heo, Tae-Hwe, E-mail: thhur92@catholic.ac.kr

Highlights: {yields} Catechin reduces the expression level of ER stress marker protein in type I Gaucher disease cells. {yields} Catechin induces the proliferation rate of GD cells similar levels to normal cells. {yields} Catechin improves wound healing activity. {yields} Catechin-mediated reductions in ER stress may be associated with enhanced cell survival. {yields} We identified catechin as a protective agent against ER stress in GD cells. -- Abstract: Gaucher disease (GD) is the most common lysosomal storage disorder (LSD) and is divided into three phenotypes, I, II, and III. Type I is the most prevalent form and has its onset inmore » adulthood. The degree of endoplasmic reticulum (ER) stress is one of the factors that determine GD severity. It has recently been reported that antioxidants reduce ER stress and apoptosis by scavenging the oxidants that cause oxidative stress. For this report, we investigated the possibility that catechin can act on type I GD patient cells to alleviate the pathogenic conditions of GD. We treated GD cells with catechin and examined the expression level of GRP78/BiP (an ER stress marker) by western blots and fluorescence microscopy, the proliferation rate of GD cells, and scratch-induced wound healing activity. Our results show that catechin reduces the expression level of GRP78/BiP, leads to cell proliferation rates of GD cells similar levels to normal cells, and improves wound healing activity. We conclude that catechin protects against ER stress in GD cells and catechin-mediated reductions in ER stress may be associated with enhanced cell survival.« less

Electrophilic aromatic substitution of catechins: Bromination and benzylation

Treesearch

G.W. McGraw; Richard W. Hemingway

1982-01-01

Relative yields of C-6, C-8. and C-6 and C-8 substituted catechins obtained from the reaction of (+)-catechin or 3',4',5-7-tetra-O-methyl-(+)-catechin with pyridinium hydrobromide-perbromide, bromine, p-hydroxybenzyl alcohol, or o-hydroxybenzyl alcohol showed differing selectivities depending upon the...

Effects of the pure flavonoids epicatechin and quercetin on vascular function and cardiometabolic health: a randomized, double-blind, placebo-controlled, crossover trial.

PubMed

Dower, James I; Geleijnse, Johanna M; Gijsbers, Lieke; Zock, Peter L; Kromhout, Daan; Hollman, Peter C H

2015-05-01

Prospective cohort studies showed inverse associations between the intake of flavonoid-rich foods (cocoa and tea) and cardiovascular disease (CVD). Intervention studies showed protective effects on intermediate markers of CVD. This may be due to the protective effects of the flavonoids epicatechin (in cocoa and tea) and quercetin (in tea). We investigated the effects of supplementation of pure epicatechin and quercetin on vascular function and cardiometabolic health. Thirty-seven apparently healthy men and women aged 40-80 y with a systolic blood pressure (BP) between 125 and 160 mm Hg at screening were enrolled in a randomized, double-blind, placebo-controlled, crossover trial. CVD risk factors were measured before and after 4 wk of daily flavonoid supplementation. Participants received (-)-epicatechin (100 mg/d), quercetin-3-glucoside (160 mg/d), or placebo capsules for 4 wk in random order. The primary outcome was the change in flow-mediated dilation from pre- to postintervention. Secondary outcomes included other markers of CVD risk and vascular function. Epicatechin supplementation did not change flow-mediated dilation significantly (1.1% absolute; 95% CI: -0.1%, 2.3%; P = 0.07). Epicatechin supplementation improved fasting plasma insulin (Δ insulin: -1.46 mU/L; 95% CI: -2.74, -0.18 mU/L; P = 0.03) and insulin resistance (Δ homeostasis model assessment of insulin resistance: -0.38; 95% CI: -0.74, -0.01; P = 0.04) and had no effect on fasting plasma glucose. Epicatechin did not change BP (office BP and 24-h ambulatory BP), arterial stiffness, nitric oxide, endothelin 1, or blood lipid profile. Quercetin-3-glucoside supplementation had no effect on flow-mediated dilation, insulin resistance, or other CVD risk factors. Our results suggest that epicatechin may in part contribute to the cardioprotective effects of cocoa and tea by improving insulin resistance. It is unlikely that quercetin plays an important role in the cardioprotective effects of tea. This study was registered at clinicaltrials.gov as NCT01691404. © 2015 American Society for Nutrition.

Preparation of tea catechins using polyamide.

PubMed

Ye, Jian-Hui; Wang, Liu-Xiang; Chen, Hao; Dong, Jun-Jie; Lu, Jian-Liang; Zheng, Xin-Qiang; Wu, Ming-Yan; Liang, Yue-Rong

2011-02-01

An adsorption separation method using Polyamide-6 (PA) as an adsorbent was developed to separate catechins from green tea extract. The adsorption capacity of total catechins for PA was 193.128 mg g⁻¹ with an adsorption selectivity coefficient K(A)(B) of total catechins over caffeine 21.717, which was better than macroporous resin model HPD 600. The Langmuir model and the pseudo-second order mode were primely fitted to describe its equilibrium data and adsorption kinetics, respectively. PA column separation by two-step elution using water and 80% (v/v) aqueous ethanol was established to prepare catechins complex which contained 670.808 mg g⁻¹ total catechins and 1.828 mg g⁻¹ caffeine. It is considered that PA was a promising adsorbent for selective isolation of catechins. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

The protective activity of tea catechins against experimental infection by Vibrio cholerae O1.

PubMed

Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Hara, Y; Shimamura, T

1992-01-01

Tea catechins inhibited the fluid accumulation induced by cholera toxin in sealed adult mice. The catechins also reduced fluid accumulation by Vibrio cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea catechins may possess protective activity against V. cholerae O1.

Co-delivery of hydrophobic curcumin and hydrophilic catechin by a water-in-oil-in-water double emulsion.

PubMed

Aditya, N P; Aditya, Sheetal; Yang, Hanjoo; Kim, Hye Won; Park, Sung Ook; Ko, Sanghoon

2015-04-15

Curcumin and catechin are naturally occurring phytochemicals with extreme sensitivity to oxidation and low bioavailability. We fabricated a water-in-oil-in-water (W/O/W) double emulsion encapsulating hydrophilic catechin and hydrophobic curcumin simultaneously. The co-loaded emulsion was fabricated using a two-step emulsification method, and its physicochemical properties were characterised. Volume-weighted mean size (d43) of emulsion droplets was ≈3.88 μm for blank emulsions, whereas it decreased to ≈2.8-3.0 μm for curcumin and/or catechin-loaded emulsions, which was attributed to their capacity to act as emulsifiers. High entrapment efficiency was observed for curcumin and/or catechin-loaded emulsions (88-97%). Encapsulation of catechin and curcumin within an emulsion increased their stability significantly in simulated gastrointestinal fluid, which resulted in a four-fold augmentation in their bioaccessibility compared to that of freely suspended curcumin and catechin solutions. Co-loading of curcumin and catechin did not have adverse effects on either compound's stability or bioaccessibility. Copyright © 2014 Elsevier Ltd. All rights reserved.

Green tea catechins: defensive role in cardiovascular disorders.

PubMed

Bhardwaj, Pooja; Khanna, Deepa

2013-07-01

Green tea, Camellia sinensis (Theaceae), a major source of flavonoids such as catechins, has recently shown multiple cardiovascular health benefits through various experimental and clinical studies. These studies suggest that green tea catechins prevent the incidence of detrimental cardiovascular events, and also lower the cardiovascular mortality rate. Catechins present in green tea have the ability to prevent atherosclerosis, hypertension, endothelial dysfunction, ischemic heart diseases, cardiomyopathy, cardiac hypertrophy and congestive heart failure by decreasing oxidative stress, preventing inflammatory events, reducing platelet aggregation and halting the proliferation of vascular smooth muscle cells. Catechins afford an anti-oxidant effect by inducing anti-oxidant enzymes, inhibiting pro-oxidant enzymes and scavenging free radicals. Catechins present anti-inflammatory activity through the inhibition of transcriptional factor NF-κB-mediated production of cytokines and adhesion molecules. Green tea catechins interfere with vascular growth factors and thus inhibit vascular smooth muscle cell proliferation, and also inhibit thrombogenesis by suppressing platelet adhesion. Additionally, catechins could protect vascular endothelial cells and enhance vascular integrity and regulate blood pressure. In this review various experimental and clinical studies suggesting the role of green tea catechins against the markers of cardiovascular disorders and the underlying mechanisms for these actions are discussed. Copyright © 2013 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Influence of genetic and vintage factors in flavan-3-ol composition of grape seeds of a segregating Vitis vinifera population.

PubMed

Hernández, Maria M; Song, Shiren; Menéndez, Cristina M

2017-01-01

Flavan-3-ol compounds are important secondary metabolites which show high antioxidant activity and are responsible for bitterness and astringency of food products. The aim of this work was to evaluate the potential for selecting grape materials with higher seed flavanol content from a breeding population. The composition and content of flavan-3-ols from 151 genotypes obtained from crossing wine grape varieties was evaluated by UPLC in three consecutive years. Chromatograms of flavan-3-ol compounds showed the same 12 compounds for all samples, but quantitative differences were observed between genotypes as well as parental varieties. The most abundant compounds were (-)-epicatechin and (+)-catechin followed by proanthocyanidins A2 and B2. Progeny showed higher values than the parental genotypes for every detected compound indicating directional transgressive segregation. With these results genotypes with as much as five times more flavanols than their parents could be identified. The year effect was significant; however, high correlations between years for each compound indicated that there is a strong genetic component in the determination of flavanol content. Higher contents of seed flavan-3-ols can be obtained by hybridisation, and those genotypes could be used for extracting healthy phytochemicals, adding value to seeds as a sub-product in wine elaboration. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Characterization of cocoa liquors by GC-MS and LC-MS/MS: focus on alkylpyrazines and flavanols.

PubMed

Magi, Emanuele; Bono, Luca; Di Carro, Marina

2012-09-01

Flavor is one of the most important characteristics of chocolate products and is due to a complex volatile fraction, depending both on the cocoa bean genotype and the several processes occurring during chocolate production (fermentation, drying, roasting and conching). Alkylpyrazines are among the most studied volatiles, being one of the main classes of odorant compounds in cocoa products. In this work, a mass spectrometric approach was used for the comparison of cocoa liquors from different countries. A headspace solid-phase microextraction gas chromatography-mass spectrometry method was developed for the qualitative study of the volatile fraction; the standard addition method was then used for the quantitative determination of five pyrazines (2-methylpyrazine, 2,3-dimethylpyrazine, 2,5-dimethylpyrazine, 2,3,5-trimethylpyrazine and tetramethylpyrazine). Satisfactory figures of merit were obtained: Limits of quantitation were in the range 0.1-2.7 ng/g; repeatability and reproducibility varied between 3% and 7% and between 8% and 14%, respectively. The total content of the pyrazines was remarkably different in the considered samples, ranging from 99 to 708 ng/g. Tetramethylpyrazine showed the highest concentration in all samples, with a maximum value of 585 ng/g. A preliminary study was also performed on the nonvolatile fraction using LC-MS/MS, identifying some flavanols such as catechin, epicatechin and procyanidins. Copyright © 2012 John Wiley & Sons, Ltd.

Identification, quantitation, and method validation for flavan-3-ols in fermented ready-to-drink teas from the Italian market using HPLC-UV/DAD and LC-MS/MS.

PubMed

Cordero, Chiara; Canale, Francesca; Del Rio, Daniele; Bicchi, Carlo

2009-11-01

The present study is focused on flavan-3-ols characterizing the antioxidant properties of fermented tea (Camellia sinensis). These bioactive compounds, object of nutritional claims in commercial products, should be quantified with rigorous analytical procedures whose accuracy and precision have been stated with a certain level of confidence. An HPLC-UV/DAD method, able to detect and quantify flavan-3-ols in infusions and ready-to-drink teas, has been developed for routine analysis and validated by characterizing several performance parameters. The accuracy assessment has been run through a series of LC-MS/MS analyses. Epigallocatechin, (+)-catechin, (-)-epigallocatechingallate, (-)-epicatechin, (-)-gallocatechingallate, (-)-epicatechingallate, and (-)-catechingallate were chosen as markers of the polyphenolic fraction. Quantitative results showed that samples obtained from tea leaves infusion were richer in polyphenolic antioxidants than those obtained through other industrial processes. The influence of shelf-life and packaging material on the flavan-3-ols content was also considered; markers decreased, with an exponential trend, as a function of time within the shelf life while packaging materials demonstrated to influence differently the flavan-3-ol fraction composition over time. The method presented here provides quantitative results with a certain level of confidence and is suitable for a routine quality control of iced teas whose antioxidant properties are object of nutritional claim.

Metabolomics assisted fingerprint of Hypericum perforatum chemotypes and assessment of their cytotoxic activity.

PubMed

Sarrou, Eirini; Giassafaki, Lefki-Pavlina; Masuero, Domenico; Perenzoni, Daniele; Vizirianakis, Ioannis S; Irakli, Maria; Chatzopoulou, Paschalina; Martens, Stefan

2018-04-01

Hypericum perforatum is known as an important medicinal plant, used for the treatment of several diseases, while its pharmacological properties are attributed to the presence of a wide range of secondary metabolites. Due to the great chemotypic variability of Hypericum species in the nature, and the demand for standardized herbal products, a detailed phytochemical investigation was carried out on different parts (herba, leaf, flowers) from wild collected and cultivated populations, using advanced chromatographic tools. Liquid Chromatographic analysis (LC-MS/MS MRM) revealed significant variability in the secondary metabolites content of the examined methanolic extracts. The most common derivatives belong to 9 groups i.e. benzoic acids, phenylpropanoids, coumarins, flavones, flavonols, flavan-3-ols, anthocyanins, phloroglucinols and naphtodianthrones. The main polyphenolic compounds were catechin, epicatechin, quercetin, quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, neochlorogenic acid, proanthocyanidins (A and B series) and cyanidin-3-O-glucoside. In addition, the content of the characteristic compounds hypericin and hyperforin in herba crude extracts ranged between 0.5 and 1.7 mg/g and 0.6-3.3 mg/g respectively. The cytotoxic activity of the crude extracts was assessed at concentrations ranged between 0.01 and 100 μg/mL, on Caco-2 intestinal cancer cell cultures, and a cytotoxic behavior was shown only at the highest concentration of 100 μg/mL. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ultraviolet-B component of sunlight stimulates photosynthesis and flavonoid accumulation in variegated Plectranthus coleoides leaves depending on background light.

PubMed

Vidović, Marija; Morina, Filis; Milić, Sonja; Zechmann, Bernd; Albert, Andreas; Winkler, Jana Barbro; Veljović Jovanović, Sonja

2015-05-01

We used variegated Plectranthus coleoides as a model plant with the aim of clarifying whether the effects of realistic ultraviolet-B (UV-B) doses on phenolic metabolism in leaves are mediated by photosynthesis. Plants were exposed to UV-B radiation (0.90 W m(-2) ) combined with two photosynthetically active radiation (PAR) intensities [395 and 1350 μmol m(-2)  s(-1) , low light (LL) and high light (HL)] for 9 d in sun simulators. Our study indicates that UV-B component of sunlight stimulates CO2 assimilation and stomatal conductance, depending on background light. UV-B-specific induction of apigenin and cyanidin glycosides was observed in both green and white tissues. However, all the other phenolic subclasses were up to four times more abundant in green leaf tissue. Caffeic and rosmarinic acids, catechin and epicatechin, which are endogenous peroxidase substrates, were depleted at HL in green tissue. This was correlated with increased peroxidase and ascorbate peroxidase activities and increased ascorbate content. The UV-B supplement to HL attenuated antioxidative metabolism and partly recovered the phenolic pool indicating stimulation of the phenylpropanoid pathway. In summary, we propose that ortho-dihydroxy phenolics are involved in antioxidative defence in chlorophyllous tissue upon light excess, while apigenin and cyanidin in white tissue have preferentially UV-screening function. © 2014 John Wiley & Sons Ltd.

Effect of roasting on phenolic content and antioxidant activities of whole cashew nuts, kernels, and testa.

PubMed

Chandrasekara, Neel; Shahidi, Fereidoon

2011-05-11

The effect of roasting on the content of phenolic compounds and antioxidant properties of cashew nuts and testa was studied. Whole cashew nuts, subjected to low-temperature (LT) and high-temperature (HT) treatments, were used to determine the antioxidant activity of products. Antioxidant activities of cashew nut, kernel, and testa phenolics extracted increased as the roasting temperature increased. The highest activity, as determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, oxygen radical absorbance capacity (ORAC), hydroxyl radical scavenging capacity, Trolox equivalent antioxidant activity (TEAC), and reducing power, was achieved when nuts were roasted at 130 °C for 33 min. Furthermore, roasting increased the total phenolic content (TPC) in both the soluble and bound extracts from whole nut, kernel, and testa but decreased that of the proanthocyanidins (PC) except for the soluble extract of cashew kernels. In addition, cashew testa afforded a higher extract yield, TPC, and PC in both soluble and bound fractions compared to that in whole nuts and kernels. Phenolic acids, namely, syringic (the predominant one), gallic, and p-coumaric acids, were identified. Flavonoids, namely, (+)-catechin, (-)-epicatechin, and epigallocatechin, were also identified, and their contents increased with increasing temperature. The results so obtained suggest that HT-short time (HTST) roasting effectively enhances the antioxidant activity of cashew nuts and testa.

Ultra-fast liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry for the rapid phenolic profiling of red maple (Acer rubrum) leaves.

PubMed

Li, Chunting; Seeram, Navindra P

2018-03-07

The red maple (Acer rubrum) species is economically important to North America because of its sap, which is used to produce maple syrup. In addition, various other red maple plant parts, including leaves, were used as a traditional medicine by the Native Americans. Currently, red maple leaves are being used for nutraceutical and cosmetic applications but there are no published analytical methods for comprehensive phytochemical characterization of this material. Herein, a rapid and sensitive method using liquid chromatography with electrospray ionization time-of-flight tandem mass spectrometry was developed to characterize the phenolics in a methanol extract of red maple leaves and a proprietary phenolic-enriched red maple leaves extract (Maplifa™). Time-of-flight mass spectrometry and tandem mass spectrometry experiments led to the identification of 106 phenolic compounds in red maples leaves with the vast majority of these compounds also detected in Maplifa™. The compounds included 68 gallotannins, 25 flavonoids, gallic acid, quinic acid, catechin, epicatechin, and nine other gallic acid derivatives among which 11 are potentially new and 75 are being reported from red maple for the first time. The developed method to characterize red maple leaves phenolics is rapid and highly sensitive and could aid in future standardization and quality control of this botanical ingredient. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The influence of condensed tannin structure on rate of microbial mineralization and reactivity to chemical assays.

PubMed

Norris, Charlotte E; Preston, Caroline M; Hogg, Karen E; Titus, Brian D

2011-03-01

We examined how tannin structure influences reactivity in tannin assays and carbon and nitrogen mineralization. Condensed tannins from the foliage of ten tree and shrub species and from pecan shells (Carya illinoensis) had different proportions of: (a) epicatechin (cis) and catechin (trans) isomers, (b) procyanidin (PC) and prodelphinidin (PD) monomers, and (c) different chain lengths. The response of each tannin to several widely used tannin assays was determined. Although there was some variation in response to proanthocyanidin (butanol/HCl) and Folin Ciocalteu assays, we did not deduce any predictable relationship between tannin structure and response to either assay. There was little variation in protein precipitation among the different tannins. To assess biological activity, six of the tannins were incubated with forest humus for 22 days. We determined that, while PC-based tannins remained at least partly extractable for the duration of the incubation, tannins with a high proportion of PD subunits rapidly became unextractable from soil. There was a positive correlation between net nitrogen mineralization and cis chemical structure. Carbon mineralization was enhanced initially by the addition of tannins to humus, but after 22 days, a negative correlation between the proportion of cis subunits and respiration was determined. Overall, we were not able to demonstrate consistent effects of structure on either microbial mineralization or reactivity to chemical assays; such relationships remain elusive.

Secondary metabolites of seven Hypericum species growing in Turkey.

PubMed

Cirak, Cuneyt; Radusiene, Jolita; Jakstas, Valdas; Ivanauskas, Liudas; Seyis, Fatih; Yayla, Fatih

2016-10-01

Context The genus Hypericum (Hypericaceae) has attracted remarkable scientific interest as its members have yielded many bioactive compounds. Objective The current study presents investigations on the accumulation of hypericin, pseudohypericin, hyperforin, adhyperforin, chlorogenic acid, neochlorogenic acid, caffeic acid, 2,4-dihydroxybenzoic acid, 13,118-biapigenin, hyperoside, isoquercitrin, quercitrin, quercetin, avicularin, rutin, (+)-catechin and (-)-epicatechin in seven Hypericum (Hypericaceae) species growing wild in Turkey, namely, H. aviculariifolium Jaup. and Spach subsp. aviculariifolium (Freyn and Bornm.) Robson var. albiflorum (endemic), H. bithynicum Boiss., H. calycinum L., H. cardiophyllum Boiss., H. elongatum L. subsp. microcalycinum (Boiss. and Heldr.) Robson, H. hirsutum L. and H. xylosteifolium (Spach) N. Robson. Materials and methods The plant materials were collected at flowering period and dissected in different tissues. Air-dried plant material including stems, leaves and flowers was mechanically powdered with a laboratory mill and samples (0.1 g) were extracted in 10 mL of 100% methanol by ultrasonication at 40 °C for 30 min for HPLC-PDA analyses. Results Accumulation levels of the investigated compounds varied greatly depending on species and plant part. Discussion For the first time, the detailed chemical profiles of corresponding Turkish Hypericum species were reported and the results were discussed from a phytochemical point of view. Conclusions The present data have importance in evaluation of plant resources of Hypericum genus in selecting the new potential sources of bioactive compounds.

Valorization of solid wastes from chestnut industry processing: Extraction and optimization of polyphenols, tannins and ellagitannins and its potential for adhesives, cosmetic and pharmaceutical industry.

PubMed

Aires, Alfredo; Carvalho, Rosa; Saavedra, Maria José

2016-02-01

The aim of the current study was to evaluate the potential of chestnut peels to produce pomaces enhanced with tannins to be used in the formulations of wood adhesives, leather tanning or as natural antioxidants in food, cosmetic and pharmaceutical industry. An analytical procedure was planned as 2 factorial design to analyze the influence of solvent (water, Na2SO3 and NaOH at different concentrations of 1, 2, 4, and 8% in water) and extraction time (30, 60, and 120, 240, 480 and 960min) on extraction yield, pH, Stiasny index, and tannins. HPLC-diode array detector equipped with an ionization mass spectrophotometer was used to assess the polyphenol composition. Our results showed that both extraction properties and phytochemicals were significantly affected (P<0.001) by all independent factors. The main tannins identified were the hydrolyzable gallic acid, vescalagin castalagin and ellagic acid, and the condensed epigallocatechin, catechin and epicatechin. The solvent 1% Na2SO3 was more effective to extract the condensed tannins whilst hydrolyzable tannins were extracted efficiently by 1% NaOH. The multivariable analysis and the Pearson's correlation coefficients showed a direct association between Stiasny number and the average levels of condensed tannins. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biochemical characterization of Aspergillus oryzae native tannase and the recombinant enzyme expressed in Pichia pastoris.

PubMed

Mizuno, Toshiyuki; Shiono, Yoshihito; Koseki, Takuya

2014-10-01

In this study, the biochemical properties of the recombinant tannase from Aspegillus oryzae were compared with those of the native enzyme. Extracellular native tannase was purified from a commercial enzyme source. Recombinant tannase highly expressed in Pichia pastoris was prepared as an active extracellular protein. Purified native and recombinant tannases produced smeared bands with apparent molecular masses of 45-80 kDa and 45-75 kDa, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After N-deglycosylation, the native enzyme yielded molecular masses of 33 kDa and 30 kDa, whereas the recombinant enzyme yielded molecular masses of 34 kDa and 30 kDa. Purified native and recombinant tannases had an optimum pH of 4.0-5.0 and 5.0, respectively, and were stable up to 40°C. After N-deglycosylation, both enzymes exhibited reduced thermostability. Catalytic efficiencies of both purified enzymes were greater with natural substrates, such as (-)-catechin, (-)-epicatechin, and (-)-epigallocatechin gallates, than those with synthetic substrates, such as methyl, ethyl, and propyl gallates. However, there were no activities against the methyl esters of ferulic, p-coumaric, caffeic, and sinapic acids, which indicate feruloyl esterase activity, or the ethyl, propyl, and butyl esters of 4-hydroxybenzoic acid, which indicate paraben hydrolase activity. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Red grape (Vitis vinifera L.) flavonoids down-regulate collagen type III expression after UV-A in primary human dermal blood endothelial cells.

PubMed

Di Francesco, Serena; Savio, Monica; Bloise, Nora; Borroni, Giovanni; Stivala, Lucia Anna; Borroni, Riccardo G

2018-05-09

Red grape (Vitis vinifera L.) flavonoids including flavan-3-ols (e.g., catechin and epicatechin), flavonols (e.g., quercetin) and anthocyanins (e.g., malvidin) exert anti-inflammatory and antioxidant activities. In the skin they also have a photoprotective action, and their effects have been extensively investigated in keratinocytes, melanocytes and fibroblasts. Despite their known effects also on blood vasculature, little is known on their activities on human dermal blood endothelial cells (HDBECs), which are critically involved in skin homeostasis as well as in the pathogenesis of neoplastic and inflammatory skin diseases. We sought to study the biological effects of selected red grape flavonoids in preventing the consequences of ultraviolet (UV)-A irradiation in vitro. Our results show that red grape flavonoids prevent UV-A-induced sICAM-1 release in HDBECs, suggesting that this cell type could represent an additional target of the anti-inflammatory activity of flavonoids. In addition, flavonoids effectively inhibited UV-A-induced synthesis of collagen type III at both RNA and protein level, indicating that dermal blood microvasculature could be actively involved in ECM remodelling as a consequence of skin photo-ageing, and that this can be prevented by red grape flavonoids. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

[Cacoa and dark chocolate in cardiovascular prevention?].

PubMed

Belz, G G; Mohr-Kahaly, S

2011-12-01

It has been shown that the consumption of cocoa has a positive influence on a number of cardiovascular surrogate parameters such as arterial vasodilatation and a moderate decrease in blood pressure in humans. In the blood, a decrease in platelet aggregation and an increase in angiogenetic progenitor cells was noted. Furthermore, anti-inflammatory effects, an amelioration of the lipid profile and glucose metabolism was described. An increase of endothelial NO production following the ingestion of the antioxidant cocoa flavanols catechin and epicatechin seems to be the leading mechanism causing these effects. In animal studies of myocardial reperfusion, a decrease in infarct size was noted. In several prospective cohort studies from Europe and the United States, a 50 % reduction of mortality mostly due to a reduction of myocardial infarction was published. Consumption up to about 25 g daily of a flavanol rich dark chocolate (ca. 85 % cocoa content) can be recommended for cardiovascular prevention. In this moderate dosage, the potentially harmful effects due to weight gain and cadmium intake will be minimal. However, controlled randomized trials with well defined clinical endpoints are needed to prove the positive effects described so far. At this point, in time based on the information described in this article, a moderate consumption of flavanol rich cocoa products seems to be effective in the prevention of coronary artery disease and myocardial infarction. © Georg Thieme Verlag KG Stuttgart · New York.

Oxygen radical absorbance capacity (ORAC) of cyclodextrin-solubilized flavonoids, resveratrol and astaxanthin as measured with the ORAC-EPR method

PubMed Central

Sueishi, Yoshimi; Ishikawa, Misa; Yoshioka, Daisuke; Endoh, Nobuyuki; Oowada, Shigeru; Shimmei, Masashi; Fujii, Hirotada; Kotake, Yashige

2012-01-01

Recently, we proposed an oxygen radical absorbance capacity method that directly quantifies the antioxidant’s scavenging capacity against free radicals and evaluated the radical scavenging abilities for water soluble antioxidant compounds. In this study, we determined the radical scavenging abilities of lipophilic antioxidants which were solubilized by cyclodextrin in water. Commonly employed fluorescence-based method measures the antioxidant’s protection capability for the fluorescent probe, while we directly quantify free-radical level using electron paramagnetic resonance spin trapping technique. In addition, the spin trapping-based method adopted controlled UV-photolysis of azo-initiator for free radical generation, but in fluorescence-based method, thermal decomposition of azo-initiator was utilized. We determined the radical scavenging abilities of seven well-known lipophilic antioxidants (five flavonoids, resveratrol and astaxanthin), using methylated β-cyclodextrin as a solubilizer. The results indicated that the agreement between spin trapping-based and fluorescence-based values was only fair partly because of a large variation in the previous fluorescence-based data. Typical radical scavenging abilities in trolox equivalent unit are: catechin 0.96; epicatechin 0.94; epigallocatechin gallate 1.3; kaempferol 0.37; myricetin 3.2; resveratrol 0.64; and astaxanthin 0.28, indicating that myricetin possesses the highest antioxidant capacity among the compounds tested. We sorted out the possible causes of the deviation between the two methods. PMID:22448093

Oxygen radical absorbance capacity (ORAC) of cyclodextrin-solubilized flavonoids, resveratrol and astaxanthin as measured with the ORAC-EPR method.

PubMed

Sueishi, Yoshimi; Ishikawa, Misa; Yoshioka, Daisuke; Endoh, Nobuyuki; Oowada, Shigeru; Shimmei, Masashi; Fujii, Hirotada; Kotake, Yashige

2012-03-01

Recently, we proposed an oxygen radical absorbance capacity method that directly quantifies the antioxidant's scavenging capacity against free radicals and evaluated the radical scavenging abilities for water soluble antioxidant compounds. In this study, we determined the radical scavenging abilities of lipophilic antioxidants which were solubilized by cyclodextrin in water. Commonly employed fluorescence-based method measures the antioxidant's protection capability for the fluorescent probe, while we directly quantify free-radical level using electron paramagnetic resonance spin trapping technique. In addition, the spin trapping-based method adopted controlled UV-photolysis of azo-initiator for free radical generation, but in fluorescence-based method, thermal decomposition of azo-initiator was utilized. We determined the radical scavenging abilities of seven well-known lipophilic antioxidants (five flavonoids, resveratrol and astaxanthin), using methylated β-cyclodextrin as a solubilizer. The results indicated that the agreement between spin trapping-based and fluorescence-based values was only fair partly because of a large variation in the previous fluorescence-based data. Typical radical scavenging abilities in trolox equivalent unit are: catechin 0.96; epicatechin 0.94; epigallocatechin gallate 1.3; kaempferol 0.37; myricetin 3.2; resveratrol 0.64; and astaxanthin 0.28, indicating that myricetin possesses the highest antioxidant capacity among the compounds tested. We sorted out the possible causes of the deviation between the two methods.

Effect of drying of figs (Ficus carica L.) on the contents of sugars, organic acids, and phenolic compounds.

PubMed

Slatnar, Ana; Klancar, Urska; Stampar, Franci; Veberic, Robert

2011-11-09

Fresh figs were subjected to two different drying processes: sun-drying and oven-drying. To assess their effect on the nutritional and health-related properties of figs, sugars, organic acids, single phenolics, total phenolics, and antioxidant activity were determined before and after processing. Samples were analyzed three times in a year, and phenolic compounds were determined using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). In figs, monomer sugars predominate, which is important nutritional information, and the content of sugars as well as organic acids in fresh figs was lower than in dried fruits. However, the best sugar/organic acid ratio was measured after the sun-drying process. Analysis of individual phenolic compounds revealed a higher content of all phenolic groups determined after the oven-drying process, with the exception of cyanidin-3-O-rutinoside. Similarly, higher total phenolic content and antioxidant activity were detected after the drying process. With these results it can be concluded that the differences in analyzed compounds in fresh and dried figs are significant. The differences between the sun-dried and oven-dried fruits were determined in organic acids, sugars, chlorogenic acid, catechin, epicatechin, kaempferol-3-O-glucoside, luteolin-8-C-glucoside, and total phenolic contents. The results indicate that properly dried figs can be used as a good source of phenolic compounds.

New perspectives on proanthocyanidin biochemistry and molecular regulation.

PubMed

Marles, M A Susan; Ray, Heather; Gruber, Margaret Y

2003-09-01

Our understanding of proanthocyanidin (syn. condensed tannin) synthesis has been recently extended by substantial developments concerning both structural and regulatory genes. A gene encoding leucoanthocyanidin reductase has been obtained from the tropical forage, Desmodium uncinatum, with the latter enzyme catalyzing formation of (+)-catechin. The BANYULS gene in Arabidopsis thaliana, previously proposed to encode leucoanthocyanidin reductase or to regulate proanthocyanidin biosynthesis, has been shown instead to encode anthocyanidin reductase, which in turn converts anthocyanidins (pelargonidin, cyanidin, or delphinidin) into 2,3-cis-2R,3R-flavan-3-ols (respectively, (-)-epiafzelechin, (-)-epicatechin and (-)-epigallocatechin). However, the enzyme which catalyzes the polymerization reaction remains unknown. Nevertheless, a vacuolar transmembrane protein TT12, defined by the Arabidopsis tt12 mutant, is involved in transport of proanthocyanidin polymer into the vacuole for accumulation. Six different types of regulatory elements, e.g. TFIIIA-like, WD-40-like, WRKY-like, MADS-box-like, myb-like, and bHLH (myc-like), have been cloned and identified using mutants from Arabidopsis (tt1, ttg1, ttg2, tt2, tt16, tt2, tt8) and two other species (Hordeum vulgare [ant13] and Lotus spp [tan1]). Accordingly, increases in proanthocyanidin levels have been induced in the the world's major forage, alfalfa. These advances may now lead to a detailed understanding of how PA synthesis is controlled and to useful alterations in proanthocyanidin concentration for the improvement of forage species, pulses, and other crop plants.

Green tea catechins and their metabolites in human skin before and after exposure to ultraviolet radiation.

PubMed

Clarke, Kayleigh A; Dew, Tristan P; Watson, Rachel E B; Farrar, Mark D; Osman, Joanne E; Nicolaou, Anna; Rhodes, Lesley E; Williamson, Gary

2016-01-01

Dietary flavonoids may protect against sunburn inflammation in skin. Preliminary reports using less complete analysis suggest that certain catechins and their metabolites are found in skin biopsies and blister fluid after consumption of green tea; however, it is not known if they are affected by solar-simulated ultraviolet radiation (UVR) or whether conjugated forms, with consequently altered bioactivity, are present. The present study tested the hypothesis that UVR affects the catechin levels in the skin of healthy volunteers after consumption of green tea and how catechins in the plasma are related to their presence in skin tissue samples. In an open oral intervention study, 11 subjects consumed green tea and vitamin C supplements daily for 3months. Presupplementation and postsupplementation plasma samples, suction blister fluid and skin biopsies were collected; the latter two samples were collected both before and after UVR. A sensitive high-performance liquid chromatography/mass spectrometric assay was used to measure the intact catechin metabolites, conjugates and free forms. Seven green tea catechins and their corresponding metabolites were identified postsupplementation in skin biopsies, 20 in blister fluid and 26 in plasma, with 15 green tea catechin metabolites present in both blister fluid and plasma. The valerolactone, O-methyl-M4-O-sulfate, a gut microbiota metabolite of catechins, was significantly increased 1.6-fold by UVR in blister fluid samples. In conclusion, there were some common catechin metabolites in the plasma and blister fluid, and the concentration was always higher in plasma. The results suggest that green tea catechins and metabolites are bioavailable in skin and provide a novel link between catechin metabolites derived from the skin and gut microbiota. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Green tea catechins and their metabolites in human skin before and after exposure to ultraviolet radiation☆☆☆★

PubMed Central

Clarke, Kayleigh A.; Dew, Tristan P.; Watson, Rachel E.B.; Farrar, Mark D.; Osman, Joanne E.; Nicolaou, Anna; Rhodes, Lesley E.; Williamson, Gary

2016-01-01

Dietary flavonoids may protect against sunburn inflammation in skin. Preliminary reports using less complete analysis suggest that certain catechins and their metabolites are found in skin biopsies and blister fluid after consumption of green tea; however, it is not known if they are affected by solar-simulated ultraviolet radiation (UVR) or whether conjugated forms, with consequently altered bioactivity, are present. The present study tested the hypothesis that UVR affects the catechin levels in the skin of healthy volunteers after consumption of green tea and how catechins in the plasma are related to their presence in skin tissue samples. In an open oral intervention study, 11 subjects consumed green tea and vitamin C supplements daily for 3 months. Presupplementation and postsupplementation plasma samples, suction blister fluid and skin biopsies were collected; the latter two samples were collected both before and after UVR. A sensitive high-performance liquid chromatography/mass spectrometric assay was used to measure the intact catechin metabolites, conjugates and free forms. Seven green tea catechins and their corresponding metabolites were identified postsupplementation in skin biopsies, 20 in blister fluid and 26 in plasma, with 15 green tea catechin metabolites present in both blister fluid and plasma. The valerolactone, O-methyl-M4-O-sulfate, a gut microbiota metabolite of catechins, was significantly increased 1.6-fold by UVR in blister fluid samples. In conclusion, there were some common catechin metabolites in the plasma and blister fluid, and the concentration was always higher in plasma. The results suggest that green tea catechins and metabolites are bioavailable in skin and provide a novel link between catechin metabolites derived from the skin and gut microbiota. PMID:26454512

(-) Epicatechin prevents alterations in lysosomal glycohydrolases, cathepsins and reduces myocardial infarct size in isoproterenol-induced myocardial infarcted rats.

PubMed

Prince, Ponnian Stanely Mainzen

2013-04-15

The preventive effects of (-) epicatechin on oxidative stress, cardiac mitochondrial damage, altered membrane bound adenosine triphosphatases and minerals were reported previously in isoproterenol-induced myocardial infarction model. Leakage of lysosomal glycohydrolases and cathepsins play an important role in the pathology of myocardial infarction. This study was aimed to evaluate the preventive effects of (-) epicatechin on alterations in lysosomal glycohydrolases, cathepsins and myocardial infarct size in isoproterenol-induced myocardial infarcted rats. Male albino Wistar rats were pretreated with (-) epicatechin (20mg/kg body weight) daily for a period of 21 days. After the pretreatment period, isoproterenol (100mg/kg body weight) was injected subcutaneously into the rats at an interval of 24h for two days to induce myocardial infarction. The levels of serum cardiac troponin-I and the activities of serum and heart lysosomal enzymes (β-glucuronidase, β-N-acetyl glucosaminidase, β-galactosidase, cathepsin-B and cathepsin-D) were increased significantly (P<0.05) and the activities of β-glucuronidase and cathepsin-D in the heart lysosomal fractions were significantly (P<0.05) decreased in isoproterenol-induced myocardial infarcted rats. The in vitro study revealed the potent antioxidant action of (-) epicatechin. Pretreatment with (-) epicatechin daily for a period of 21 days prevented the leakage of cardiac marker, lysosomal glycohydrolases, cathepsins, and reduced infarct size, thereby protecting the lysosomal membranes in isoproterenol-induced myocardial infarcted rats, by virtue of its membrane stabilizing property. Copyright © 2013 Elsevier B.V. All rights reserved.

Flavonoids uptake and their effect on cell cycle of human colon adenocarcinoma cells (Caco2)

PubMed Central

Salucci, M; Stivala, L A; Maiani, G; Bugianesi, R; Vannini, V

2002-01-01

Green tea, mainly through its constituents epigallocatechin gallate, epigallocatechin, epicatechin gallate and epicatechin, has demonstrated anticarcinogenic activity in several animal models, including those for skin, lung and gastro-intestinal tract cancer, although less is known about colorectal cancer. Quercetin, the major flavonoid present in vegetables and fruit, exerts potential anticarcinogenic effects in animal models and cell cultures, but less is known about quercetin glucosides. The objectives of this study were to investigate (i) the antioxidant activity of the phenolic compounds epicatechin, epigallocatechin gallate, gallic acid and quercetin-3-glucoside; (ii) the cytotoxicity of different concentrations of epicatechin, epigallocatechin gallate, and gallic acid; (iii) the cellular uptake of epicatechin, epigallocatechin gallate, gallic acid and quercetin-3-glucoside and (iv) their effect on the cell cycle. Human colon adenocarcinoma cells were used as experimental model. The results of this study indicate that all dietary flavonoids studied (epicatechin, epigallocatechin gallate, gallic acid and quercetin-3-glucoside) show a significant antioxidant effect in a chemical model system, but only epigallocatechin gallate or gallic acid are able to interfere with the cell cycle in Caco2 cell lines. These data suggest that the antioxidant activity of flavonoids is not related to the inhibition of cellular growth. From a structural point of view, the galloyl moiety appears to be required for both the antioxidant and the antiproliferative effects. British Journal of Cancer (2002) 86, 1645–1651. DOI: 10.1038/sj/bjc/6600295 www.bjcancer.com © 2002 Cancer Research UK PMID:12085217

Antibacterial activity of nitric oxide releasing silver nanoparticles

NASA Astrophysics Data System (ADS)

Seabra, Amedea B.; Manosalva, Nixson; de Araujo Lima, Bruna; Pelegrino, Milena T.; Brocchi, Marcelo; Rubilar, Olga; Duran, Nelson

2017-06-01

Silver nanoparticles (AgNPs) are well known potent antimicrobial agents. Similarly, the free radical nitric oxide (NO) has important antibacterial activity, and due to its instability, the combination of NO and nanomaterials has been applied in several biomedical applications. The aim of this work was to synthesize, characterize and evaluate the antibacterial activity of a new NO-releasing AgNPs. Herein, AgNPs were synthesized by the reduction of silver ions (Ag+) by catechin, a natural polyphenol and potent antioxidant agent, derived from green tea extract. Catechin acts as a reducing agent and as a capping molecule on the surface of AgNPs, minimizing particle agglomeration. The as-synthesized nanoparticles were characterized by different techniques. The results showed the formation of AgNPs with average hydrodynamic size of 44 nm, polydispersity index of 0.21, and zeta potential of -35.9 mV. X-ray diffraction and Fourier transform infrared spectroscopy revealed the presence of the AgNP core and cathecin as capping agent. The low molecular weight mercaptosuccinic acid (MSA), which contain free thiol group, was added on the surface of catechin-AgNPs, leading to the formation of MSA-catechin-AgNPs (the NO precursor nanoparticle). Free thiol groups of MSA-catechin-AgNPs were nitrosated leading to the formation of S-nitroso-mercaptosuccinic acid (S-nitroso-MSA), the NO donor. The amount of 342 ± 16 µmol of NO was released per gram of S-nitroso-MSA-catechin-AgNPs. The antibacterial activities of catechin-AgNPs, MSA-catechin-AgNPs, and S-nitroso-MSA-catechin-AgNPs were evaluated towards different resistant bacterial strains. The results demonstrated an enhanced antibacterial activity of the NO-releasing AgNP. For instance, the minimal inhibitory concentration values for Pseudomonas aeruginosa (ATCC 27853) incubated with AgNPs-catechin, AgNPs-catechin-MSA, and AgNPs-catechin-S-nitroso-MSA were found to be 62, 125 and 3 µg/mL, respectively. While in the case of Klebsiella pneumoniae (ATCC 700603) the minimum bactericidal concentration values for treatments with AgNPs-catechin, AgNPs-catechin-MSA, and AgNPs-catechin-S-nitroso-MSA were found to be 1000, 500, and 125 µg/mL, respectively. The antibacterial actions of the NO-releasing nanoparticle were superior in comparison with the antibacterial effects of AgNPs, in most of the tested antibiotic resistant bacteria strains. These results highlight the promising uses of NO-releasing AgNPs against resistant bacteria in several biomedical applications.

Synthesis of modified proanthocyanidins: introduction of acyl substituents at C-8 of catechin. Selective synthesis of a C-4-->O-->C-3 ether-linked procyanidin-like dimer.

PubMed

Beauhaire, Josiane; Es-Safi, Nour-Eddine; Boyer, François-Didier; Kerhoas, Lucien; Guernevé, Christine le; Ducrot, Paul-Henri

2005-02-01

The regioselective introduction of substituents at C-8 of (+)-catechin is described, leading to the synthesis of several catechin derivatives with various substitution patterns to be used for the further synthesis of modified proanthocyanidins. Thereafter, a new 3-O-4 ether-linked procyanidin-like derivative was synthesized. Its formation was selectively achieved through TiCl(4)-catalyzed condensation of 4-(2-hydroxyethoxy)tetra-O-benzyl catechin with the 8-trifluoroacetyl adduct of tetra-O-benzyl catechin.

The effect of copper(II), iron(II) sulphate, and vitamin C combinations on the weak antimicrobial activity of (+)-catechin against Staphylococcus aureus and other microbes.

PubMed

Holloway, Andrew C; Mueller-Harvey, Irene; Gould, Simon W J; Fielder, Mark D; Naughton, Declan P; Kelly, Alison F

2012-12-01

Few attempts have been made to improve the activity of plant compounds with low antimicrobial efficacy. (+)-Catechin, a weak antimicrobial tea flavanol, was combined with putative adjuncts and tested against different species of bacteria. Copper(II) sulphate enhanced (+)-catechin activity against Pseudomonas aeruginosa but not Staphylococcus aureus, Proteus mirabilis or Escherichia coli. Attempts to raise the activity of (+)-catechin against two unresponsive species, S. aureus and E. coli, with iron(II) sulphate, iron(III) chloride, and vitamin C, showed that iron(II) enhanced (+)-catechin against S. aureus, but not E. coli; neither iron(III) nor combined iron(II) and copper(II), enhanced (+)-catechin activity against either species. Vitamin C enhanced copper(II) containing combinations against both species in the absence of iron(II). Catalase or EDTA added to active samples removed viability effects suggesting that active mixtures had produced H(2)O(2)via the action of added metal(II) ions. H(2)O(2) generation by (+)-catechin plus copper(II) mixtures and copper(II) alone could account for the principal effect of bacterial growth inhibition following 30 minute exposures as well as the antimicrobial effect of (+)-catechin-iron(II) against S. aureus. These novel findings about a weak antimicrobial flavanol contrast with previous knowledge of more active flavanols with transition metal combinations. Weak antimicrobial compounds like (+)-catechin within enhancement mixtures may therefore be used as efficacious agents. (+)-Catechin may provide a means of lowering copper(II) or iron(II) contents in certain crop protection and other products.

Inhibition of proliferation of human lung cancer cells by green tea catechins is mediated by upregulation of let-7

PubMed Central

ZHONG, ZHIWEI; DONG, ZHUO; YANG, LIHUA; CHEN, XIAOQIANG; GONG, ZHAOHUI

2012-01-01

Green tea catechins are known to function as anticancer agents via inhibition of carcinogenesis during the initiation, promotion and progression stages. Many potential mechanisms have been proposed, yet the precise mechanism of lung cancer prevention by green tea catechins remains unclear. microRNAs (miRs) are a class of 21–24 nucleotide small non-coding RNAs and play critical roles throughout cellular development and regulation. Emerging evidence demonstrates that tea catechins influence the expression of miRs in human cancer cells to inhibit tumorigenesis. Both let-7a-1 and let-7g were detected in the human lung cancer cells treated with tea catechins. The cell viability and cell cycle were analyzed after tea catechins treatment. In the present study, we found that tea catechins upregulated the tumor-suppressor miRs, let-7a-1 and let-7g, in lung cancer cell lines. The upregulation of let-7a/7g repressed the expression of their targets, C-MYC and the regulatory protein of LIN-28, at the mRNA and protein levels. Moreover, the cell growth assay indicated that tea catechins significantly inhibited cell proliferation, and the flow cytometric analysis revealed an increase in the number of cells in the G2/M phase and a decrease in the number of cells in the S phase after treatment with tea catechins. These observations suggest that green tea catechins mediate the inhibition of proliferation of lung cancer cells through the let-7 signaling pathway. PMID:22970031

The effects of co-administration of butter on the absorption, metabolism and excretion of catechins in rats after oral administration of tea polyphenols.

PubMed

Zhang, Liang; Han, Yuhui; Xu, Liwei; Liang, Yuhong; Chen, Xin; Li, Junsong; Wan, Xiaochun

2015-07-01

In Southwest China, tea polyphenols are usually utilized by way of butter tea. Tea polyphenols inhibit the absorption and biosynthesis of fatty acids in vivo, but the effects of butter on the pharmacokinetics of tea polyphenols have drawn less concern. A rapid UHPLC-MS/MS method was used to quantitatively determine the catechins in the plasma, feces and bile of rats after the oral administration of tea polyphenol or its combination with butter. In comparison with the single tea polyphenol treatment, the maximum plasma concentrations (Cmax) of the free EGCG, EGC, EC, GCG, GC and ECG significantly decreased after the co-administration of butter. The mean residence times (MRT) of the free EGCG, EGC, EC, GC and ECG were also significantly prolonged. When the plasma samples were treated with β-glucuronidase and arylsulfatase, the pharmacokinetic parameters of the total catechins (free and conjugated forms) were not affected by the co-administration of butter. These results indicated that the total absorption of catechins was not affected by butter, but the metabolism of catechins had been changed. Furthermore, the fecal catechins were significantly increased by butter. The total fecal amount and excretion ratio of all catechins were increased highly. The biliary excretion of EGCG, EGC, EC, GCG and GC was significantly increased by the co-administration of butter. To sum up, the butter changed the metabolism of catechins in vivo by decreasing the plasma concentration of the free catechins but increasing the conjugated catechins.

Synthesis and Property of Ag(NP)/catechin/Gelatin Nanofiber

NASA Astrophysics Data System (ADS)

Nasir, Muhamad; Apriani, Dita

2017-12-01

Nanomaterial play important role future industry such as for the medical, food, pharmaceutical and cosmetic industry. Ag (NP) and catechin exhibit antibacterial property. Ag(NP) with diameter around 15 nm was synthesis by microwaved method. We have successfully produce Ag(NP)/catechin/gelatin nanofiber composite by electrospinning process. Ag(NP)/catechin/gelatin nanofiber was synthesized by using gelatin from tuna fish, polyethylene oxide (PEO), acetic acid as solvent and silver nanoparticle(NP)/catechin as bioactive component, respectively. Morphology and structure of bioactive catechin-gelatin nanofiber were characterized by scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR), respectively. SEM analysis showed that morphology of nanofiber composite was smooth and had average diameter 398.97 nm. FTIR analysis results were used to confirm structure of catechin-gelatin nanofiber. It was confirmed by FTIR that specific vibration band peak amide A (N-H) at 3286,209 cm-1, amide B (N-H) 3069,396 cm-1, amide I (C=O) at 1643,813 cm-1, amide II (N-H and CN) at 1538,949 cm-1, amide III (C-N) at 1276,789 cm-1, C-O-C from polyethylene oxide at 1146,418 cm-1, respectively. When examined to S. Aureus bacteria, Ag/catechin/gelatin nanofiber show inhabitation performance around 40.44%. Ag(NP)/catechin/gelatin nanofiber has potential application antibacterial medical application.

Green tea (Camellia sinensis) catechins and vascular function.

PubMed

Moore, Rosalind J; Jackson, Kim G; Minihane, Anne M

2009-12-01

The health benefits of green tea (Camellia sinensis) catechins are becoming increasingly recognised. Amongst the proposed benefits are the maintenance of endothelial function and vascular homeostasis and an associated reduction in atherogenesis and CVD risk. The mounting evidence for the influential effect of green tea catechins on vascular function from epidemiological, human intervention and animal studies is subject to review together with exploration of the potential mechanistic pathways involved. Epigallocatechin-3-gallate, one of the most abundant and widely studied catechin found in green tea, will be prominent in the present review. Since there is a substantial inconsistency in the published data with regards to the impact of green tea catechins on vascular function, evaluation and interpretation of the inter- and intra-study variability is included. In conclusion, a positive effect of green tea catechins on vascular function is becoming apparent. Further studies in animal and cell models using physiological concentrations of catechins and their metabolites are warranted in order to gain some insight into the physiology and molecular basis of the observed beneficial effects.

Structure-dependent phytotoxicity of catechins and other flavonoids: flavonoid conversions by cell-free protein extracts of Centaurea maculosa (spotted knapweed) roots.

PubMed

Bais, Harsh Pal; Walker, Travis S; Kennan, Alan J; Stermitz, Frank R; Vivanco, Jorge M

2003-02-12

Invasive plants are believed to succeed in part by secretion of allelochemicals, thus displacing competing plant species. Centaurea maculosa (spotted knapweed) provides a classic example of this process. We have previously reported that spotted knapweed roots secrete (+/-)-catechin and that (-)-catechin, but not (+)-catechin, is phytotoxic and hence may be a major contributor to C. maculosa's invasive behavior in the rhizosphere. In this communication, we explore both structure/activity relationships for flavonoid phytotoxicity and possible biosynthetic pathways for root production of (+/-)-catechin. Kaempferol and dihydroquercetin were shown to be phytotoxic, while quercetin was not. Kaempferol was converted to dihydroquercetin and (+/-)-catechin when treated with total root protein extracts from C. maculosa, but quercetin was not. This finding suggests an alteration in the standard flavonoid biosynthetic pathway in C. maculosa roots, whereby kaempferol is not a dead-end product but serves as a precursor to dihydroquercetin, which in turn leads to (+/-)-catechin production.

Magnetic catechin-dextran conjugate as targeted therapeutic for pancreatic tumour cells.

PubMed

Vittorio, Orazio; Voliani, Valerio; Faraci, Paolo; Karmakar, Biswajit; Iemma, Francesca; Hampel, Silke; Kavallaris, Maria; Cirillo, Giuseppe

2014-06-01

Catechin-dextran conjugates have recently attracted a lot of attention due to their anticancer activity against a range of cancer cells. Magnetic nanoparticles have the ability to concentrate therapeutically important drugs due to their magnetic-spatial control and provide opportunities for targeted drug delivery. Enhancement of the anticancer efficiency of catechin-dextran conjugate by functionalisation with magnetic iron oxide nanoparticles. Modification of the coating shell of commercial magnetic nanoparticles (Endorem) composed of dextran with the catechin-dextran conjugate. Catechin-dextran conjugated with Endorem (Endo-Cat) increased the intracellular concentration of the drug and it induced apoptosis in 98% of pancreatic tumour cells placed under magnetic field. The conjugation of catechin-dextran with Endorem enhances the anticancer activity of this drug and provides a new strategy for targeted drug delivery on tumour cells driven by magnetic field. The ability to spatially control the delivery of the catechin-dextran by magnetic field makes it a promising agent for further application in cancer therapy.

Role of chlorogenic acid quinone and interaction of chlorogenic acid quinone and catechins in the enzymatic browning of apple.

PubMed

Amaki, Kanako; Saito, Eri; Taniguchi, Kumiko; Joshita, Keiko; Murata, Masatsune

2011-01-01

Chlorogenic acid (CQA) is one of the major polyphenols in apple and a good substrate for the polyphenol oxidase (PPO) in apple. Apple contains catechins as well as CQA, and the role of CQA quinone and its interaction with catechins in the enzymatic browning of apple were examined. Browning was repressed and 2-cysteinyl-CQA was formed when cysteine was added to apple juice. CQA quinone was essential for browning to occur. Although catechins and CQA were oxidized by PPO, some catechins seemed to be non-enzymatically oxidized by CQA quinone.

An Intracellular Laccase Is Responsible for Epicatechin-Mediated Anthocyanin Degradation in Litchi Fruit Pericarp1[OPEN

PubMed Central

Fang, Fang; Zhang, Xue-lian; Gong, Yi-hui; Li, Wen-jun; Shi, Zhao-wan; He, Quan; Wu, Qing; Li, Lu; Jiang, Lin-lin; Cai, Zhi-gao; Oren-Shamir, Michal; Zhang, Zhao-qi

2015-01-01

In contrast to the detailed molecular knowledge available on anthocyanin synthesis, little is known about its catabolism in plants. Litchi (Litchi chinensis) fruit lose their attractive red color soon after harvest. The mechanism leading to quick degradation of anthocyanins in the pericarp is not well understood. An anthocyanin degradation enzyme (ADE) was purified to homogeneity by sequential column chromatography, using partially purified anthocyanins from litchi pericarp as a substrate. The purified ADE, of 116 kD by urea SDS-PAGE, was identified as a laccase (ADE/LAC). The full-length complementary DNA encoding ADE/LAC was obtained, and a polyclonal antibody raised against a deduced peptide of the gene recognized the ADE protein. The anthocyanin degradation function of the gene was confirmed by its transient expression in tobacco (Nicotiana benthamiana) leaves. The highest ADE/LAC transcript abundance was in the pericarp in comparison with other tissues, and was about 1,000-fold higher than the polyphenol oxidase gene in the pericarp. Epicatechin was found to be the favorable substrate for the ADE/LAC. The dependence of anthocyanin degradation by the enzyme on the presence of epicatechin suggests an ADE/LAC epicatechin-coupled oxidation model. This model was supported by a dramatic decrease in epicatechin content in the pericarp parallel to anthocyanin degradation. Immunogold labeling transmission electron microscopy suggested that ADE/LAC is located mainly in the vacuole, with essential phenolic substances. ADE/LAC vacuolar localization, high expression levels in the pericarp, and high epicatechin-dependent anthocyanin degradation support its central role in pigment breakdown during pericarp browning. PMID:26514808

Determination of catechin in lotus rhizomes by high-performance liquid chromatography.

PubMed

Yan, Shou-Lei; Wang, Qing-Zhang; Peng, Guang-Hua

2009-08-01

A novel method was developed to analyze lotus rhizome polyphenolic catechin using high-performance liquid chromatography (HPLC). The retain time of catechin was 14.72 min under the optimized condition. Mass spectrometry was further employed to qualify and quantify the purity of the catechin peak. Good linearity (R=0.9997) was obtained within the range of 50-1,000 ng. The coefficient of variance was determined as 5.2%, with a recovery rate of 97%. The detection and quantification limitations of catechin were 23 ng and 50 ng, respectively. The catechin level was 0.0025% in the lotus rhizome, and 0.011% in the knot of the lotus rhizome (Nelumbo nucifera cv. 'damao jie'). The optimized conditions of HPLC for catechin detection in the lotus rhizome matrix were as follows: the SuperlcosIL™ LC-18 analytical column (150 mm×4.6 mm, 5 µm), methanol-water-acetic acid (10:90:1, volume ratio) as the mobile phase, an UV detector at 280 nm, a flow rate of 0.8 ml/min, column temperature at 30°C, and an injection volume of 10 µl.

Accumulation of catechins in tea in relation to accumulation of mRNA from genes involved in catechin biosynthesis.

PubMed

Eungwanichayapant, P D; Popluechai, S

2009-02-01

Catechins are a group of polyphenols found in tea (Camellia sinensis var. sinensis) at high levels. They are beneficial for health. From the study on accumulation of catechins in shoots and mature leaves of a tea cultivar, Oolong No. 17, using high-performance liquid chromatography (HPLC), it was found that the amounts of most catechins in the shoots were higher than those in the mature leaves, with an exception of catechins gallate (CG) that was found in trace amounts in both the shoots and mature leaves. mRNA accumulation of genes involved in catechin synthesis was studied using reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that the mRNA accumulation of the genes were higher in the shoots than in the mature leaves. These genes included genes of phenylalanine ammonia-lyase 1 (PAL1; EC 4.3.1.5), chalcone synthase (CHS; EC 2.3.1.74), dihydroflavonol 4-reductase (DFR; EC 1.1.1.219), leucoanthocyanidin reductase (LCR; EC 1.17.1.3), and flavanone 3-hydroxylase (F3H; EC 1.14.11.9).

Pharmacokinetic study of gallocatechin-7-gallate from Pithecellobium clypearia Benth. in rats.

PubMed

Li, Chao; Song, Xiaowei; Song, Junke; Pang, Xiaocong; Wang, Zhe; Zhao, Ying; Lian, Wenwen; Liu, Ailin; Du, Guanhua

2016-01-01

The pharmacokinetic profile of gallocatechin-7-gallate (J10688) was studied in rats after intravenous administration. Male and female Sprague-Dawley (SD) rats received 1, 3, and 10 mg/kg (i.v.) of J10688 and plasma drug concentrations were determined by a high performance liquid chromatography-mass spectrometry (LC-MS) method. The pharmacokinetic software Data Analysis System (Version 3.0) was used to calculate the pharmacokinetic parameters. For different i.v. doses of J10688, the mean peak plasma concentration (C 0) values ranged from 11.26 to 50.82 mg/L, and mean area under the concentration-time curve (AUC0-t ) values ranged from 1.75 to 11.80 (mg·h/L). J10688 lacked dose-dependent pharmacokinetic properties within doses between 1 and 10 mg/kg, based on the power model. The method developed in this study was sensitive, precise, and stable. The pharmacokinetic properties of J10688 in SD rats were shown to have rapid distribution and clearance values. These pharmacokinetic results may contribute to an improved understanding of the pharmacological actions of J10688.

An Intracellular Laccase Is Responsible for Epicatechin-Mediated Anthocyanin Degradation in Litchi Fruit Pericarp.

PubMed

Fang, Fang; Zhang, Xue-lian; Luo, Hong-hui; Zhou, Jia-jian; Gong, Yi-hui; Li, Wen-jun; Shi, Zhao-wan; He, Quan; Wu, Qing; Li, Lu; Jiang, Lin-lin; Cai, Zhi-gao; Oren-Shamir, Michal; Zhang, Zhao-qi; Pang, Xue-qun

2015-12-01

In contrast to the detailed molecular knowledge available on anthocyanin synthesis, little is known about its catabolism in plants. Litchi (Litchi chinensis) fruit lose their attractive red color soon after harvest. The mechanism leading to quick degradation of anthocyanins in the pericarp is not well understood. An anthocyanin degradation enzyme (ADE) was purified to homogeneity by sequential column chromatography, using partially purified anthocyanins from litchi pericarp as a substrate. The purified ADE, of 116 kD by urea SDS-PAGE, was identified as a laccase (ADE/LAC). The full-length complementary DNA encoding ADE/LAC was obtained, and a polyclonal antibody raised against a deduced peptide of the gene recognized the ADE protein. The anthocyanin degradation function of the gene was confirmed by its transient expression in tobacco (Nicotiana benthamiana) leaves. The highest ADE/LAC transcript abundance was in the pericarp in comparison with other tissues, and was about 1,000-fold higher than the polyphenol oxidase gene in the pericarp. Epicatechin was found to be the favorable substrate for the ADE/LAC. The dependence of anthocyanin degradation by the enzyme on the presence of epicatechin suggests an ADE/LAC epicatechin-coupled oxidation model. This model was supported by a dramatic decrease in epicatechin content in the pericarp parallel to anthocyanin degradation. Immunogold labeling transmission electron microscopy suggested that ADE/LAC is located mainly in the vacuole, with essential phenolic substances. ADE/LAC vacuolar localization, high expression levels in the pericarp, and high epicatechin-dependent anthocyanin degradation support its central role in pigment breakdown during pericarp browning. © 2015 American Society of Plant Biologists. All Rights Reserved.

Preparation of catechin extracts and nanoemulsions from green tea leaf waste and their inhibition effect on prostate cancer cell PC-3

PubMed Central

Tsai, Yin-Jieh; Chen, Bing-Huei

2016-01-01

Green tea is one of the most commonly consumed natural health beverages in Taiwan’s market, with the major functional component catechin being shown to possess several biological activities such as antioxidation, anticancer, and prevention of cardiovascular disease. The objectives of this study were to develop a high-performance liquid chromatography–mass spectrometry method to determine the variety and content of catechins in green tea leaf waste, a by-product obtained during processing of tea beverage. In addition, catechin nanoemulsion was prepared to study its inhibition effect on prostate cancer cell PC-3. Results showed that a total of eight catechin standards were separated within 25 minutes by using a Gemini C18 column and a gradient mobile phase of 0.1% formic acid (A) and acetonitrile (B) with flow rate at 1 mL/min, column temperature at 30°C, and detection wavelength at 280 nm. Among various extraction solvents, 50% ethanol generated the highest yield of total catechins from tea leaf waste, of which five catechins were identified and quantified. The catechin nanoemulsion was composed of catechin extract, lecithin, Tween 80, and deionized water in an appropriate proportion, with the mean particle size being 11.45 nm, encapsulation efficiency 88.1%, and zeta potential −66.3 mV. A high stability of catechin nanoemulsion was shown over a storage period of 120 days at 4°C. Both catechin extract and nanoemulsion could inhibit growth of PC-3 tumor cells, with the half maximal inhibitory concentration being 15.4 μg/mL and 8.5 μg/mL, respectively. The PC-3 cell cycle was arrested at S phase through elevation of P27 expression and decline of cyclin A, cyclin B, cyclin-dependent kinase 2, and cyclin-dependent kinase 1 expression. In addition, both catechin extract and nanoemulsion could induce apoptosis of PC-3 cells through decrease in B-cell lymphoma 2 (bcl-2) expression and increase in cytochrome c expression for activation of caspase-3, caspase-8, and caspase-9. Taken together, both caspase-dependent and caspase-independent pathways may be involved in apoptosis of PC-3 cells. PMID:27226712

Evaluation of medicinal plant extracts and isolated compound epicatechin from Ricinus communis against Paramphistomum cervi.

PubMed

Zahir, Abdul Abduz; Rahuman, Abdul Abdul; Bagavan, Asokan; Geetha, Kannappan; Kamaraj, Chinnaperumal; Elango, Gandhi

2012-10-01

The purpose of this study is to determine the efficacies of hexane, chloroform, ethyl acetate, acetone, and methanol leaf extracts of Euphorbia hirta L., Psidium guajava L., Ricinus communis L., Solanum trilobatum L., and Tridax procumbens L. against sheep fluke Paramphistomum cervi (Digenea: Paramphistomatidae). All plant extracts showed moderate effects after 24 h of exposure; however, the highest parasite mortality was found in the methanol extract of R. communis. In the present study, bioassay-guided fractionation of methanol extract of R. communis led to the separation and identification of epicatechin as a potential new compound (LC(50) = 31.2; LC(90) = 105.0 ppm) against P. cervi. The structures were established from infrared, ultraviolet, (1)H-nuclear magnetic resonance (NMR), (13)C-NMR, and mass spectral data which confirmed the identification of the compound epicatechin from R. communis. Results of this study showed that the methanol extract of R. communis may be considered as a potent source and epicatechin as a new natural parasitic agent.

Proteomic evaluation of myofibrillar carbonylation in chilled fish mince and its inhibition by catechin.

PubMed

Pazos, Manuel; Maestre, Rodrigo; Gallardo, José M; Medina, Isabel

2013-01-01

The present study investigates the susceptibility of individual myofibrillar proteins from mackerel (Scomber scombrus) mince to undergo carbonylation reactions during chilled storage, and the antioxidant capacity of (+)-catechin to prevent oxidative processes of proteins. The carbonylation of each particular protein was quantified by combining the labelling of protein carbonyls by fluorescein-5-thiosemicarbazide (FTSC) with 1-D or 2-D gel electrophoresis. Alpha skeletal actin, glycogen phosphorylase, unnamed protein product (UNP) similar to enolase, pyruvate kinase, isoforms of creatine kinase, aldolase A and an isoform of glyceraldehyde 3-phosphate dehydrogenase (G3PDH) showed elevated oxidation in chilled non-supplemented mince. Myosin heavy chain (MHC) was not carbonylated in chilled muscle, but an extensive MHC degradation was observed in those samples. The supplementation of catechin reduced protein oxidation and lipid oxidation in a concentration-dependent manner: control>25>100≈200ppm. Therefore, the highest catechin concentrations (100 and 200ppm) exhibited the strongest antioxidant activity. Catechin (200ppm) reduced significantly carbonylation of protein spots identified as glycogen phosphorylase, pyruvate kinase muscle isozyme, isoforms of creatine kinase. Conversely, catechin was ineffective to inhibit the oxidation of actin and UNP similar to enolase. These results draw attention to the inefficiency of catechin to prevent actin oxidation, in contrast to the extremely high efficiency of catechin in inhibiting oxidation of lipids and other proteins. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dextran-Catechin: An anticancer chemically-modified natural compound targeting copper that attenuates neuroblastoma growth

PubMed Central

Vittorio, Orazio; Brandl, Miriam; Cirillo, Giuseppe; Kimpton, Kathleen; Hinde, Elizabeth; Gaus, Katharina; Yee, Eugene; Kumar, Naresh; Duong, Hien; Fleming, Claudia; Haber, Michelle; Norris, Murray; Boyer, Cyrille; Kavallaris, Maria

2016-01-01

Neuroblastoma is frequently diagnosed at advanced stage disease and treatment includes high dose chemotherapy and surgery. Despite the use of aggressive therapy survival rates are poor and children that survive their disease experience long term side effects from their treatment, highlighting the need for effective and less toxic therapies. Catechin is a natural polyphenol with anti-cancer properties and limited side effects, however its mechanism of action is unknown. Here we report that Dextran-Catechin, a conjugated form of catechin that increases serum stability, is preferentially and markedly active against neuroblastoma cells having high levels of intracellular copper, without affecting non-malignant cells. Copper transporter 1 (CTR1) is the main transporter of copper in mammalian cells and it is upregulated in neuroblastoma. Functional studies showed that depletion of CTR1 expression reduced intracellular copper levels and led to a decrease in neuroblastoma cell sensitivity to Dextran-Catechin, implicating copper in the activity of this compound. Mechanistically, Dextran-Catechin was found to react with copper, inducing oxidative stress and decreasing glutathione levels, an intracellular antioxidant and regulator of copper homeostasis. In vivo, Dextran-Catechin significantly attenuated tumour growth in human xenograft and syngeneic models of neuroblastoma. Thus, Dextran-Catechin targets copper, inhibits tumour growth, and may be valuable in the treatment of aggressive neuroblastoma and other cancers dependent on copper for their growth. PMID:27374085

Comparison of the bioavailability of quercetin and catechin in rats.

PubMed

Manach, C; Texier, O; Morand, C; Crespy, V; Régérat, F; Demigné, C; Rémésy, C

1999-12-01

Quercetin and catechin are present in noticeable amounts in human diet and these polyphenolic compounds are supposed to exert beneficial effects on human health. However, their metabolic fates in the organism have never been compared. In the present study, rats were fed a 0.25% quercetin or a 0.25% catechin diet. Quercetin and catechin metabolites were analyzed in plasma and liver samples by high-performance liquid chromatography coupled to an ultraviolet or a multielectrode coulometric detection. All plasma metabolites were present as conjugated forms, but catechin metabolites were mainly constituted by glucuronidated derivatives, whereas quercetin metabolites were sulfo- and glucurono-sulfo conjugates. Quercetin was more intensively methylated than catechin in plasma. The plasma quercetin metabolites are well maintained during the postabsorptive period (approximately 50 microM), whereas the concentration of catechin metabolites dropped dramatically between 12- and 24-h after an experimental meal (from 38.0 to 4.5 microM). In the liver, the concentrations of quercetin and catechin derivatives were lower than in plasma, and no accumulation was observed when the rats were adapted for 14 d to the supplemented diets. The hepatic metabolites were intensively methylated (90-95%), but in contrast to plasma, some free aglycones could be detected. Thus, it clearly appears that studies dealing with the biological impact of these polyphenols should take into account the feature of their bioavailability, particularly the fact that their circulating metabolites are conjugated derivatives.

Microemulsion formulation design and evaluation for hydrophobic compound: Catechin topical application.

PubMed

Lin, Yu-Hsiang; Tsai, Ming-Jun; Fang, Yi-Ping; Fu, Yaw-Syan; Huang, Yaw-Bin; Wu, Pao-Chu

2018-01-01

The aim of the present study was to design a microemulsion for catechin topical application. A mixture experimental design with five independent variables (X 1 : oil, X 2 : surfactant, X 3 : catechin, X 4 : cosurfactant and X 5 : water) was developed, and the response surface methodology was used to study the effect of formulation components on physiochemical characteristics and penetration capacity of a catechin-loaded microemulsion, and to obtain an optimal microemulsion formulation. The results showed that the drug-loaded microemulsion formation and characteristics were related to many parameters of the components. The transdermal amounts in receiver cells and skin deposition amount remarkably increased about 4.1-111.6-fold and 0.6-7.6-fold respectively. The lag time was significantly shortened from 10h to 1.0-6.7h. The optimal formulation with 20% surfactant, 30% cosurfactant and 2.6% Catechin was subjected to stability and irritation tests. The results showed that the physicochemical characteristics and catechin level of the drug-loaded microemulsion did not show significant degradation after 3 months of storage at 25°C.The catechin-loaded microemulsion did not cause significant irritation compared to the water-treated group. Copyright © 2017 Elsevier B.V. All rights reserved.

Complexing of Green Tea Catechins with Food Constituents and Degradation of the Complexes by Lactobacillus plantarum

PubMed Central

HAYASHI, Taeko; UEDA, Shuhei; TSURUTA, Hiroki; KUWAHARA, Hiroshige; OSAWA, Ro

2012-01-01

Complexing of green tea catechins with food constituents and their hydrolysis by tannase-producing Lactobacillus plantarum strains, were investigated. Our observations indicated that 1) epigallocatechin gallate (EGCg) and other catechin galloyl esters bound with food ingredients (i.e., proteins) to form a complex that is likely to be unabsorbable through the intestinal wall, whereas most catechins not esterified with gallic acid (GA) remain in free form, not complexing with food ingredients; 2) tannase activity of L. plantarum is strain dependent, possibly grouped into those with high tannase activity hydrolyzing EGCg to epigallocatechin and GA and those with the low activity; and 3) L. plantarum strains with high tannase activity are capable of hydrolyzing not only intact EGCg but also EGCg and other catechin galloyl esters complexed with dietary proteins to free non-galloyl ester catechins and GA. The evidence suggests that L. plantarum with high tannase activity, if it colonizes the human intestine, would release free non-galloyl-ester catechins and GA that are readily absorbed through the human intestinal epithelia from the complexes, thereby ensuring maximum delivery of the bioactive polyphenols of green tea to the host. PMID:24936346

Topical application of ointment containing 0.5% green tea catechins suppresses tongue oxidative stress in 5-fluorouracil administered rats.

PubMed

Miyai, Hisataka; Maruyama, Takayuki; Tomofuji, Takaaki; Yoneda, Toshiki; Azuma, Tetsuji; Mizuno, Hirofumi; Sugiura, Yoshio; Kobayashi, Terumasa; Ekuni, Daisuke; Morita, Manabu

2017-10-01

The purpose of this study was to investigate the preventive effects of topical application of green tea catechins on tongue oxidative stress induced by 5-fluorouracil (5-FU) administration in rats. Male Wistar rats (n=28, 8 weeks old) were divided into four groups of seven rats each: a negative control group (saline administration and application of ointment without green tea catechins), a positive control group (5-FU administration and application of ointment without green tea catechins), and two experimental groups (5-FU administration and application of ointment containing 0.1% or 0.5% green tea catechins). Topical application of each ointment to the ventral surface of the tongue was performed once a day for 5days. The level of 8-hydroxydeoxyguanosine (8-OHdG) was determined to evaluate oxidative stress. Fluorescence staining was also performed to confirm nuclear factor erythroid 2-related factor 2 (Nrf2) translocation to the nucleus. After the experimental period, the ratios of 8-OHdG-positive cells in the ventral tongue tissue were higher in the positive control group than in the negative control group (P<0.05). On the other hand, those in the 0.5% green tea catechin group, but not in the 0.1% green tea catechin group, were lower than the positive control group (P<0.05). In addition, Nrf2 translocation to the nucleus was greater in the 0.5% green tea catechin group than in the positive control group (P<0.05). Topical application of ointment containing 0.5% green tea catechins could prevent tongue oxidative stress in 5-FU administered rats, via up-regulation of the Nrf2 signaling pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

Non-classic androgen actions in Sertoli cell membrane in whole seminiferous tubules: effects of nandrolone decanoate and catechin.

PubMed

Cavalari, Fernanda Carvalho; de Castro, Alexandre Luz; Fracasso, Bianca de Moraes; Loss, Eloísa da Silveira

2012-01-01

Studies show a mechanism of action of testosterone, nandrolone and catechin as agonists of the membrane androgen receptor. The aim of this work is to investigate the non-classical effect of androgens and catechin in Sertoli cells from immature rats. The membrane potential of Sertoli cells in whole seminiferous tubules was recorded using a standard single microelectrode technique. It was performed a topical application of testosterone (1 μM), nandrolone (0.1, 0.5 and 1 μM) and the flavonoid catechin (0.1, 0.5 and 1 μM) alone and also after infusion with flutamide (1 μM), diazoxide (100 μM) or U73122 (1 μM). The immature testes were incubated for 5 min in KRb with (45)Ca(2+), with or without nandrolone (1 μM). The results were given as mean±SEM. The data were analyzed using ANOVA for repeated measures with Bonferroni post-test. Testosterone produces a depolarization in the membrane potential at 120 s after application. Catechin (1 μM) and nandrolone (1 μM) have shown a similar response to testosterone: depolarization at 120 s after the application. The same response of catechin and nandrolone was observed at different doses. The effects of testosterone, catechin and nandrolone were not affected after perfusion with flutamide. Perfusion with diazoxide and U73122 nullified the effect of nandrolone (1 μM) and catechin (1 μM). Nandrolone and testosterone increased (45)Ca(2+) uptake with or without flutamide within 5min. These results indicate that nandrolone and catechin act through a receptor on the plasmatic membrane, as well as testosterone, showing a non-classical pathway in Sertoli cells from immature rat testes. Copyright © 2011 Elsevier Inc. All rights reserved.

Impact of (+/-)-catechin on soil microbial communities.

PubMed

Inderjit; Kaur, Rajwant; Kaur, Surinder; Callaway, Ragan M

2009-01-01

Catechin is a highly studied but controversial allelochemical reported as a component of the root exudates of Centaurea maculosa. Initial reports of high and consistent exudation rates and soil concentrations have been shown to be highly inaccurate, but the chemical has been found in root exudates at and much less frequently in soil but sporadically at high concentrations. Part of the problem of detection and measuring phytotoxicity in natural soils may be due to the confounding effect of soil microbes, and little is known about interactions between catechin and soil microbes. Here we tested the effect of catechin on soil microbial communities and the feedback of these effects to two plant species. We found that catechin inhibits microbial activity in the soil we tested, and by doing so appears to promote plant growth in the microbe-free environment. This is in striking contrast to other in vitro studies, emphasizing the highly conditional effects of the chemical and suggesting that the phytotoxic effects of catechin may be exerted through the microbes in some soils.

Impact of (±)-catechin on soil microbial communities

PubMed Central

Kaur, Rajwant; Kaur, Surinder

2009-01-01

Catechin is a highly studied but controversial allelochemical reported as a component of the root exudates of Centaurea maculosa. Initial reports of high and consistent exudation rates and soil concentrations have been shown to be highly inaccurate, but the chemical has been found in root exudates at and much less frequently in soil but sporadically at high concentrations. Part of the problem of detection and measuring phytotoxicity in natural soils may be due to the confounding effect of soil microbes, and little is known about interactions between catechin and soil microbes. Here we tested the effect of catechin on soil microbial communities and the feedback of these effects to two plant species. We found that catechin inhibits microbial activity in the soil we tested, and by doing so appears to promote plant growth in the microbe-free environment. This is in striking contrast to other in vitro studies, emphasizing the highly conditional effects of the chemical and suggesting that the phytotoxic effects of catechin may be exerted through the microbes in some soils. PMID:19704908

Plasticized poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends incorporated with catechin intended for active food-packaging applications.

PubMed

Arrieta, Marina Patricia; Castro-López, María del Mar; Rayón, Emilio; Barral-Losada, Luis Fernando; López-Vilariño, José Manuel; López, Juan; González-Rodríguez, María Victoria

2014-10-15

Active biobased packaging materials based on poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends were prepared by melt blending and fully characterized. Catechin incorporation, as antioxidant compound, enhanced the thermal stability, whereas its release was improved by the addition of acetyl(tributyl citrate) (ATBC) as plasticizer. Whereas the incorporation of ATBC resulted in a reduction of elastic modulus and hardness, catechin addition produced more rigid materials due to hydrogen-bonding interactions between catechin hydroxyl groups and carbonyl groups of PLA and PHB. The quantification of catechin released into a fatty food simulant and the antioxidant effectiveness after the release process were demonstrated. The effect of the materials' exposure to a food simulant was also investigated. PHB-added materials maintained their structural and mechanical properties after 10 days in a test medium that represents the worst foreseeable conditions of the intended use. Thus, plasticized PLA-PHB blends with catechin show their potential as biobased active packaging for fatty food.

Diversity of Catechin in Northeast Indian Tea Cultivars

PubMed Central

Sabhapondit, Santanu; Karak, Tanmoy; Bhuyan, Lakshi Prasad; Goswami, Bhabesh Chandra; Hazarika, Mridul

2012-01-01

Tea (Camellia sinensis L.) leaf contains a large amount of catechins (a group of very active flavonoids) which contribute to major quality attributes of black tea. Based on morphological characters tea plants were classified as Assam, China, and Cambod varieties. The present study is an attempt for biochemical fingerprinting of the tea varieties based on catechin composition in green leaf of cultivars grown in Northeast India. Assam variety cultivars contained the highest level of catechins followed by Cambod and China. The average catechin contents were 231 ± 7 mg g−1, 202 ± 5 mg g−1, and 157 ± 4 mg g−1 of dry weight of green leaf for Assam, Cambod, and China cultivars, respectively. Among the individual catechins the variations in epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were the most prominent among the varieties. High EGC content was found to be a characteristic of Assam variety which was further corroborated through multivariate analysis. PMID:22448135

Dietary Plants for the Prevention and Management of Kidney Stones: Preclinical and Clinical Evidence and Molecular Mechanisms

PubMed Central

Nirumand, Mina Cheraghi; Hajialyani, Marziyeh; Rahimi, Roja; Farzaei, Mohammad Hosein; Nabavi, Seyed Mohammad

2018-01-01

Kidney stones are one of the oldest known and common diseases in the urinary tract system. Various human studies have suggested that diets with a higher intake of vegetables and fruits play a role in the prevention of kidney stones. In this review, we have provided an overview of these dietary plants, their main chemical constituents, and their possible mechanisms of action. Camellia sinensis (green tea), Rubus idaeus (raspberry), Rubia cordifolia (common madder), Petroselinum crispum (parsley), Punica granatum (pomegranate), Pistacia lentiscus (mastic), Solanum xanthocarpum (yellow-fruit nightshade), Urtica dioica (stinging nettle), Dolichos biflorus (horse gram), Ammi visnaga (khella), Nigella sativa (black-cumin), Hibiscus sabdariffa (roselle), and Origanum vulgare (oregano) have received considerable interest based on scientific evidence. Beside these dietary plants, phytochemicals—such as catechin, epicatechin, epigallocatechin-3-gallate, diosmin, rutin, quercetin, hyperoside, and curcumin—as antioxidant dietary phyto-phenols were found to be effective for the prevention of urolithiasis (the process of stone formation in the urinary tract). The main underlying mechanisms of these dietary plants and their isolated phytonutrients in the management of urolithiasis include diuretic, antispasmodic, and antioxidant activity, as well as an inhibitory effect on crystallization, nucleation, and aggregation of crystals. The results as presented in this review demonstrate the promising role of dietary plants and phytophenols in the prevention and management of kidney stones. Further investigations are required to confirm the safety and efficacy of these compounds. PMID:29518971

Dietary Plants for the Prevention and Management of Kidney Stones: Preclinical and Clinical Evidence and Molecular Mechanisms.

PubMed

Nirumand, Mina Cheraghi; Hajialyani, Marziyeh; Rahimi, Roja; Farzaei, Mohammad Hosein; Zingue, Stéphane; Nabavi, Seyed Mohammad; Bishayee, Anupam

2018-03-07

Kidney stones are one of the oldest known and common diseases in the urinary tract system. Various human studies have suggested that diets with a higher intake of vegetables and fruits play a role in the prevention of kidney stones. In this review, we have provided an overview of these dietary plants, their main chemical constituents, and their possible mechanisms of action. Camellia sinensis (green tea), Rubus idaeus (raspberry), Rubia cordifolia (common madder), Petroselinum crispum (parsley), Punica granatum (pomegranate), Pistacia lentiscus (mastic), Solanum xanthocarpum (yellow-fruit nightshade), Urtica dioica (stinging nettle), Dolichos biflorus ( horse gram ), Ammi visnaga (khella), Nigella sativa (black-cumin), Hibiscus sabdariffa (roselle), and Origanum vulgare (oregano) have received considerable interest based on scientific evidence. Beside these dietary plants, phytochemicals-such as catechin, epicatechin, epigallocatechin-3-gallate, diosmin, rutin, quercetin, hyperoside, and curcumin-as antioxidant dietary phyto-phenols were found to be effective for the prevention of urolithiasis (the process of stone formation in the urinary tract). The main underlying mechanisms of these dietary plants and their isolated phytonutrients in the management of urolithiasis include diuretic, antispasmodic, and antioxidant activity, as well as an inhibitory effect on crystallization, nucleation, and aggregation of crystals. The results as presented in this review demonstrate the promising role of dietary plants and phytophenols in the prevention and management of kidney stones. Further investigations are required to confirm the safety and efficacy of these compounds.

Simultaneous determination of phenolic acids and flavonoids in rice using solid-phase extraction and RP-HPLC with photodiode array detection.

PubMed

Irakli, Maria N; Samanidou, Victoria F; Biliaderis, Costas G; Papadoyannis, Ioannis N

2012-07-01

An analytical method based on an optimized solid-phase extraction procedure and followed by high-performance liquid chromatography (HPLC) separation with diode array detection was developed and validated for the simultaneous determination of phenolic acids (gallic, protocatechuic, 4-hydroxy-benzoic, vanillic, caffeic, syringic, p-coumaric, ferulic, sinapic, and cinnamic acids), flavanols (catechin and epicatechin), flavonols (myricetin, quercetin, kaempferol, quercetin-3-O-glucoside, hyperoside, and rutin), flavones (luteolin and apigenin) and flavanones (naringenin and hesperidin) in rice flour (Oryza sativa L.). Chromatographic separation was carried out on a PerfectSil Target ODS-3 (250 mm × 4.6 mm, 3 μm) column at temperature 25°C using a mobile phase, consisting of 0.5% (v/v) acetic acid in water, methanol, and acetonitrile at a flow rate 1 mL min(-1) , under gradient elution conditions. Application of optimum extraction conditions, elaborated on both Lichrolut C(18) and Oasis HLB cartridges, have led to extraction of phenolic acids and flavonoids from rice flour with mean recoveries 84.3-113.0%. The developed method was validated in terms of linearity, accuracy, precision, stability, and sensitivity. Repeatability (n = 5) and inter-day precision (n = 4) revealed relative standard deviation (RSD) <13%. The optimized method was successfully applied to the analysis of phenolic acids and flavonoids in pigmented (red and black rice) and non-pigmented rice (brown rice) samples. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous separation and identification of oligomeric procyanidins and anthocyanin-derived pigments in raw red wine by HPLC-UV-ESI-MSn.

PubMed

Pati, S; Losito, I; Gambacorta, G; La Notte, E; Palmisano, F; Zambonin, P G

2006-07-01

Samples of raw red wine (Primitivo di Manduria, Apulia, Southern Italy) were analysed without any pre-treatment (except 1:2 dilution with water) using HPLC with detection based on UV absorbance and Electrospray Ionisation Sequential Mass Spectrometry (ESI-MSn, with n = 1-3) in a series configuration. In particular, absorbance at 520 nm was monitored for UV detection in order to identify pigments responsible for wine colour. On the other hand, two subsequent stages of MS detection based on positive ions were adopted. The first consisted of an explorative MS acquisition, aimed at the individuation of the m/z ratios for positively charged compounds; the second was based on fragmentation of the detected ions within an ion trap analyser, followed by MS/MS and, if required, MS3 acquisitions. The synergy between UV detection and MSn analysis led to the identification of 41 pigments, which can be classified into five groups: grape anthocyanins, pyranoanthocyanins, vinyl-linked anthocyanin-flavanol pigments, ethyl-bridged anthocyanin-flavanol pigments and flavanol-anthocyanin compounds. Many isomeric and oligomeric structures were found within each group. A further class of compounds, not absorbing in the visible spectrum, could be also characterised by ESI-MSn and corresponded to B-type procyanidins, i.e. proanthocyanidins arising from C4-->C8/C4-->C6 couplings between catechin or epicatechin units. In particular, oligomeric structures (from dimers to pentamers), often present with several isomers, were identified and their fragmentation patterns clarified.

Increase of antioxidative potential of rat plasma by oral administration of proanthocyanidin-rich extract from grape seeds.

PubMed

Koga, T; Moro, K; Nakamori, K; Yamakoshi, J; Hosoyama, H; Kataoka, S; Ariga, T

1999-05-01

The effect of a single oral administration of proanthocyanidins, oligomeric and polymeric polyhydroxyflavan-3-ol units, on the antioxidative potential of blood plasma was studied in rats. Proanthocyanidin-rich extract from grape seeds was administered by intragastric intubation to fasted rats at 250 mg/kg of body weight. The plasma obtained from water- or proanthocyanidin-administered rats was oxidized by incubation with copper sulfate or 2, 2'-azobis(2-amidinopropane) dihydrochloride (AAPH) at 37 degrees C, and the formation of cholesteryl ester hydroperoxides (CE-OOH) was followed. The plasma obtained from proanthocyanidin-administered rats was significantly more resistant against both copper ion-induced and AAPH-induced formation of CE-OOH than that from control rats. The lag phase in the copper ion-induced oxidation of rat plasma was remarkably increased at 15 min after administration of proanthocyanidins and reached a maximum level at 30 min. When the plasma from proanthocyanidin-administered rat was hydrolyzed by sulfatase and beta-glucuronidase following analysis by high-performance liquid chromatography with electrochemical detection, metabolites of proanthocyanidins occurred in rat plasma at 15 min after administration, three peaks of which were identified as gallic acid, (+)-catechin, and (-)-epicatechin. These results suggest that the intake of proanthocyanidins, the major polyphenols in red wine, increases the resistance of blood plasma against oxidative stress and may contribute to physiological functions of plant food including wine through their in vivo antioxidative ability.

Euphorbia denticulata Lam.: A promising source of phyto-pharmaceuticals for the development of novel functional formulations.

PubMed

Zengin, Gokhan; Uysal, Ahmet; Aktumsek, Abdurrahman; Mocan, Andrei; Mollica, Adriano; Locatelli, Marcello; Custodio, Luisa; Neng, Nuno R; Nogueira, José M F; Aumeeruddy-Elalfi, Zaahira; Mahomoodally, M Fawzi

2017-03-01

In this study, Methanolic extracts of Euphorbia denticulata parts (flowers, leaf, stem, and mix of aerial parts) were assessed for a panoply of bioactivities. Inhibitory potential against key enzymes involved in diabetes (α-glucosidase and α-amylase), obesity (pancreatic lipase), neurodegenerative diseases (cholinesterases), and hyperpigmentation (tyrosinase) was evaluated. The antioxidant and antibacterial properties were also assessed. The total phenolic, flavonoid, and phytochemical profile were established using HPLC/DAD and molecular modelling studies on specific target compounds were performed in silico. The flower extract was found to be rich in phenolics and flavonoids, (60.11±1.40mgGAE/g and 42.04±0.16mgRE/g respectively), which tend to correlate with the high radical scavenging activity of this extract (120.34±3.33mgTE/g and 165.42±2.16mgTE/g for DPPH and ABTS respectively). Catechin, epicatechin, gallic acid, p-OH-Benzoic acid, rosmarinic acid, and epigallocatechin gallate, found in significant abundance in the extracts were assessed using molecular modelling with the aim to study their docking properties on a set of six enzymes used in this study. The extracts were moderately effective with MIC values ranging between 1.56 to 6.25mg/ml, but potent growth inhibitors of MRSA strains. Results amassed herein can be used as a stimulus for further studies geared towards the development of novel phyto-pharmaceuticals. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Chemical profile and antioxidant capacity verification of Psidium guajava (Myrtaceae) fruits at different stages of maturation

PubMed Central

Araújo, Heverton M.; Rodrigues, Fabíola F. G.; Costa, Wégila D.; Nonato, Carla de F. A.; Rodrigues, Fábio F. G.; Boligon, Aline A.; Athayde, Margareth L.; Costa, José G. M.

2015-01-01

Psidium guajava (Myrtaceae), a common plant in Cariri region, Ceara, Brazil, as well as in various parts of the world, contains high concentrations of bioactive compounds and in many communities its parts are used for therapeutic purposes. Studies describe antioxidant, antimicrobial and anti-diarrheal actions from extracts obtained from leaves, but information about the activities of the fruits and comparison of these at different maturity stages (immature, partially mature and mature) are scarce. This study aims to evaluate the antioxidant properties by quantifying the levels of phenolic and flavonoid compounds, carotenoids and vitamin C of P. guajava fruits at different stages of maturation. The content of phenolic compounds for the immature fruit, partially mature and mature were: 22.41; 34.61 and 32.92 mg of AG/g fraction. The flavonoid content for immature fruits, intermediate and mature were: 2.83; 5.10 and 5.65 mg RUT/g fraction, respectively. Following the same standards of maturation stages, the ascorbic acid content was determined with values of 0.48; 0.38 and 0.21 mg AA/g fraction, respectively. HPLC analysis identified and quantified the presence of gallic acid, catechin, chlorogenic acid, caffeic acid, epicatechin, rutin, quercitrin, isoquercitrin, quercetin, kaempferol, glycosylated campeferol, tocopherol, β-carotene and lycopene. The antioxidant activity carried out by DPPH method showed the mature fruits bearing the best results, whereas chelation of Fe2+ ions showed higher percentage for the immature fruit. The results obtained by lipidic peroxidation were not satisfactory. PMID:26933403

Modulatory effects of Cassia fistula fruits against free radicals and genotoxicity of mutagens.

PubMed

Kaur, Sandeep; Kumar, Manish; Kaur, Paramjeet; Kaur, Varinder; Kaur, Satwinderjeet

2016-12-01

Cassia fistula L. (Fabaceae) fruits are highly recommended in folklore medicine for curing various ailments. In the current study, methanol (CaFM), hexane (CaFH), chloroform (CaFCl), ethyl acetate (CaFE), butanol (CaFB) and aqueous (CaFA) fractions of C. fistula fruits were investigated for their potential to inhibit the genotoxicity of mutagens and free radicals. The antimutagenicity of fractions was evaluated against the reactive carcinogenic ester generating mutagen, 2-aminofluorene (2-AF) and frame-shift mutation inducing mutagen, 4-nitro-o-phenylenediamine (NPD) in Ames Salmonella typhimurium TA98 tester strain. Among the fractions, CaFE showed strongest protective effect against the mutagenicity of both S9-dependent and direct-acting mutagen with an inhibitory percentage of 81% and 64% at the concentration of 1 × 10 3 and 2.5 × 10 3 respectively. All the fractions were analyzed for free radical scavenging activity using DPPH, nitric oxide, lipid peroxidation and superoxide anion assays. CaFE fraction showed maximum antioxidant activity in comparison to other fractions with an IC 50 of 97.01, 172.36, 144 and 264.79 μg/ml respectively. High performance liquid chromatography showed the presence of catechin, epicatechin and umbelliferone in appreciable amount which may account for its efficacy in combating free radicals and also showed protective effect against the mutagenicity of S9-dependent mutagen, 2-AF. Copyright © 2016 Elsevier Ltd. All rights reserved.

Factors affecting the conversion of apple polyphenols to phenolic acids and fruit matrix to short-chain fatty acids by human faecal microbiota in vitro.

PubMed

Bazzocco, Sarah; Mattila, Ismo; Guyot, Sylvain; Renard, Catherine M G C; Aura, Anna-Marja

2008-12-01

Proanthocyanidins (PAs) in apples are condensed tannins comprised mostly of (-)-epicatechin units with some terminal (+)-catechins. PAs, especially those having a long chain-length, are absorbed in the upper intestine only to a small extent and are passed to the colon. In the colon they are subjected to microbial metabolism by colonic microbiota. In the present article, the ability of human microbiota to ferment apple PAs is studied. Freeze-dried fruit preparations (apple, enzymatically digested apple, isolated cell-walls, isolated PAs or ciders) from two varieties, Marie Ménard and Avrolles, containing PAs of different chain lengths, were compared. Fermentation studies were performed in an in vitro colon model using human faecal microbiota as an inoculum. The maximal extent of conversion to known microbial metabolites, was observed at late time point for Marie Ménard cider, having short PAs. In this case, the initial dose also contributed to the extent of conversion. Long-chain PAs were able to inhibit the in vitro microbial metabolism of PAs shown as low maxima at early time points. Presence of isolated PAs also suppressed SCFA formation from carbohydrates as compared with that from apple cell wall or faecal suspension without substrates. The low maximal extents at early time points suggest that there is a competition between the inhibitory effect of the PAs on microbial activity, and the ability to convert PAs by the microbiota.

NMR, ESI/MS, and MALDI-TOF/MS analysis of pear juice polymeric proanthocyanidins with potent free radical scavenging activity.

PubMed

Es-Safi, Nour-Eddine; Guyot, Sylvain; Ducrot, Paul-Henri

2006-09-20

The structure of a polymeric proanthocyanidin fraction isolated from pear juice was characterized by NMR, ESI/MS, and MALDI-TOF/MS analyses, and its antioxidant activity was investigated using the DPPH free radical scavenging method. The results obtained from 13C NMR analysis showed the predominance of signals representative of procyanidins. Typical signals in the chemical shift region between 70 and 90 ppm demonstrated the exclusive presence of epicatechin units. The results obtained through negative ESI/MS analysis showed singly and doubly charged ions corresponding to the molecular mass of procyanidins with a degree of polymerization up to 22. The spectra obtained through MALDI-TOF/MS analysis revealed the presence of two series of tannin oligomers. Supporting the observations from NMR spectroscopy, the first series consists of well-resolved tannin identified as procyanidin polymers units with chain lengths of up to 25. A second series of monogalloyl flavan-3-ols polymers with polymerization degree up to 25 were also detected. This is the first mass spectrometric evidence confirming the existence of galloylated procyanidin oligomers in pear fruits. Within each of these oligomers, various signals exist suggesting the presence of several oligomeric tannins. The antioxidant properties of the polymeric fraction were investigated through reduction of the DPPH free radical, and the results obtained showed that the polymeric fraction exhibited a higher antioxidant power compared to those of (+)-catechin and B3 procyanidin dimer.

Physicochemical and Antioxidant Properties of Honeys from the Sundarbans Mangrove Forest of Bangladesh

PubMed Central

Islam, M Rabiul; Pervin, Tahmina; Hossain, Hemayet; Saha, Badhan; Hossain, Sheikh Julfikar

2017-01-01

This study evaluated the physicochemical, nutritional, antioxidant, and phenolic properties of ten honey samples from the Sundarbans mangrove forest, Bangladesh. The average pH, electrical conductivity, total dissolved solid, ash, moisture, hydroxymethyl furfural, titrable acidity, and absorbance were 4.3, 0.38 mS/cm, 187.5 ppm, 0.14%, 17.88%, 4.4 mg/kg, 37.7 meq/kg, and 483 mAU, respectively. In the honeys, the average contents of Ca, Cu, Fe, K, Mg, Mn, and Na were 95.5, 0.19, 6.4, 302, 39.9, 3.4, and 597 ppm, respectively, whereas Cd, Cr, Pb, and Ni were not found. The average contents of total sugar, protein, lipid, vitamin C, polyphenols, flavonoids, and anthocyanins in the honeys were 69.3%, 0.8%, 0.29%, 107.3 mg/kg, 757.2 mg gallic acid equivalent/kg, 43.1 mg chatechin equivalent/kg, and 5.4 mg/kg, respectively. The honeys had strong 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity, reducing power and total antioxidant capacity. High-performance liquid chromatography analysis of the honey fractions revealed the quantification of six polyphenols namely, (+)-catechin, (−)-epicatechin, p-caumeric acid, syringic acid, trans-cinnamic acid, and vanillic acid at 194.98, 330.34, 74.64, 218.97, 49.55, and 118.84 mg/kg, respectively. Therefore, the honeys in the Sundarbans are of excellent quality and a prospective source of polyphenols, and antioxidants. PMID:29333387

Total phenolic compounds, flavonoids, and radical scavenging activity of 21 selected tropical plants.

PubMed

Mustafa, R A; Abdul Hamid, A; Mohamed, S; Bakar, F Abu

2010-01-01

Free radical scavenging activity of 21 tropical plant extracts was evaluated using 1,1-diphenyl-2-picrylhydrazyl assay (DPPH). Total phenolic compounds and flavonoids were determined using Folin-Ciocalteu and HPLC, respectively. Results of the study revealed that all the plants tested exhibited excellent antioxidant activity with IC(50) in the range of 21.3 to 89.6 microg/mL. The most potent activity was demonstrated by Cosmos caudatus (21.3 microg/mL) and Piper betle (23.0 microg/mL) that are not significantly different than that of -tocopherol or BHA. L. inermis extract was found to consist of the highest concentration of phenolics, catechin, epicatechin, and naringenin. High content of quercetin, myricetin, and kaempferol were identified in Vitex negundo, Centella asiatica, and Sesbania grandiflora extracts, respectively. Luteolin and apigenin, on the other hand, were found in Premna cordifolia and Kaempferia galanga extracts. Strong correlation (R = 0.8613) between total phenolic compounds and total flavonoids (R = 0.8430) and that of antioxidant activity of the extracts were observed. The study revealed that phenolic, in particular flavonoids, may be the main contributors to the antioxidant activity exhibited by the plants. Potent antioxidant from natural sources is of great interest to replace the use of synthetic antioxidants. In addition, some of the plants have great potential to be used in the development of functional ingredients/foods that are currently in demand for the health benefits associated with their use.

Grape skin phenolics as inhibitors of mammalian α-glucosidase and α-amylase--effect of food matrix and processing on efficacy.

PubMed

Lavelli, V; Sri Harsha, P S C; Ferranti, P; Scarafoni, A; Iametti, S

2016-03-01

Type-2 diabetes is continuously increasing worldwide. Hence, there is a need to develop functional foods that efficiently alleviate damage due to hyperglycaemia complications while meeting the criteria for a sustainable food processing technology. Inhibition of mammalian α-amylase and α-glucosidase was studied for white grape skin samples recovered from wineries and found to be higher than that of the drug acarbose. In white grape skins, quercetin and kaempferol derivatives, analysed by UPLC-DAD-MS, and the oligomeric series of catechin/epicatechin units and their gallic acid ester derivatives up to nonamers, analysed by MALDI-TOF-MS were identified. White grape skin was then used for enrichment of a tomato puree (3%) and a flat bread (10%). White grape skin phenolics were found in the extract obtained from the enriched foods, except for the higher mass proanthocyanidin oligomers, mainly due to their binding to the matrix and to a lesser extent to heat degradation. Proanthocyanidin solubility was lower in bread, most probably due to formation of binary proanthocyanin/protein complexes, than in tomato puree where possible formation of ternary proanthocyanidin/protein/pectin complexes can enhance solubility. Enzyme inhibition by the enriched foods was significantly higher than for unfortified foods. Hence, this in vitro approach provided a platform to study potential dietary agents to alleviate hyperglycaemia damage and suggested that grape skin phenolics could be effective even if the higher mass proanthocyanidins are bound to the food matrix.

Pouteria torta epicarp as a useful source of α-amylase inhibitor in the control of type 2 diabetes.

PubMed

de Sales, Paloma Michelle; de Souza, Paula Monteiro; Dartora, Mariana; Resck, Inês Sabioni; Simeoni, Luiz Alberto; Fonseca-Bazzo, Yris Maria; de Oliveira Magalhães, Pérola; Silveira, Dâmaris

2017-11-01

Type 2 diabetes plays a major role in public health, affecting about 400 million adults. One of the used strategies to control type 2 diabetes is the inhibition of α-amylase activity to reduce post-prandial blood glucose levels. Therefore, in past decades, the search of new α-amylase inhibitors has led to the evaluation of natural products as a source of these compounds. Pouteria torta (Sapotaceae) is widespread in Brazil and bears edible fruits. Epicarp and pulp crude extracts of fresh fruits were studied for in vitro α-amylase inhibition activity. The pulp did not present activity while epicarp, usually considered as waste, showed a high α-amylase inhibitory capacity when compared with acarbose and Triticum aestivum. Therefore, an assay-guided fractionation study of epicarp crude extract was performed. Fraction VI shows very high inhibitory activity with IC 50 of 9 μg/mL. However, subsequent fractionation led to lower inhibition potential (IC 50 of 22.1 μg/mL). The qualitative characterization of fraction VI were performed by chromatographic and spectrometric analysis and showed the presence of epicatechin, catechin, sucrose, glucose, and fructose. Total phenolic and flavonoid contents and antioxidant capacity were also assessed and there seemed to be no correlation between phenolic or flavonoids-rich fractions and antioxidant capacity or α-amylase inhibitory activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anticancer activity of rhamnoallosan against DU-145 cells is kinetically complementary to coexisting Polyphenolics in Psidium guajava budding leaves.

PubMed

Chen, Kuan-Chou; Hsieh, Chiu-Lan; Huang, Kuan-Dar; Ker, Yaw-Bee; Chyau, Charng-Cherng; Peng, Robert Y

2009-07-22

Psidium guajava L. is a valuable farm fruit plant having many medicinal uses. Previously its budding leaves (PE) were shown to contain huge amounts of soluble polyphenolics (SP) including (in mg/g) gallic acid (348), catechin (102), epicatechin (60), rutin (100), quercetin (102), and rutin (100) and to exhibit potent anticancer activity. However, reconstitution of these polyphenolics recovered only 40% of the original bioactivity, and the soluble carbohydrate (SC) portion in PE was suspected to contribute the remaining. PE contained a novel rhamnoallosan, which had a carbohydrate/protein (w/w) ratio = 29.06%/10.27% (=2.83, average molecular mass of 5029 kDa), characteristically evidencing a peptidoglycan, consisting of a composition (mole % ratio) of rhamnose/allose/arabinose/tallose/xylose/fucose/glucose/mannose/galactose = 36.05:24.24:8.76:7.95:7.37:5.90:3.69:3.19:2.85 and of amino acid (in wt %) glycine/leucine/proline/alanine/methionine/isoleucine/valine/histidine/tyrosine/phenylalanine/cysteine/aspartic acid/lysine/glutamic acid = 37.12:12.68:10.05:8.97:5.99:4.89:4.83:4.25:4.05:2.78:1.86:1.10:0.73:0.70. Kinetic analysis showed comparable apparent cell-killing rate coefficients (k(app)) to be 4.03 x 10(3) and 2.92 x 10(3) cells mg(-1) h(-1), respectively, by SP and SC, evidencing the complementary anti-DU-145 bioactivity in nature.

Effect of phenolic aldehydes and flavonoids on growth and inactivation of Oenococcus oeni and Lactobacillus hilgardii.

PubMed

Figueiredo, Ana Rita; Campos, Francisco; de Freitas, Víctor; Hogg, Tim; Couto, José António

2008-02-01

The aim of this work was to investigate the effect of wine phenolic aldehydes, flavonoids and tannins on growth and viability of strains of Oenococcus oeni and Lactobacillus hilgardii. Cultures were grown in ethanol-containing MRS/TJ medium supplemented with different concentrations of phenolic aldehydes or flavonoids and monitored spectrophotometrically. The effect of tannins was evaluated by monitoring the progressive inactivation of cells in ethanol-containing phosphate buffer supplemented with grape seed extracts with different molecular weight tannins. Of the phenolic aldehydes tested, sinapaldehyde, coniferaldehyde, p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde and 3,4,5-trihydroxybenzaldehyde significantly inhibited the growth of O. oeni VF, while vanillin and syringaldehyde had no effect at the concentrations tested. Lact. hilgardii 5 was only inhibited by sinapaldehyde and coniferaldehyde. Among the flavonoids, quercetin and kaempferol exerted an inhibitory effect especially on O. oeni VF. Myricetin and the flavan-3-ols studied (catechin and epicatechin) did not affect considerably the growth of both strains. Condensed tannins (particularly tetramers and pentamers) were found to strongly affect cell viability, especially in the case of O. oeni VF. In general, this strain was found to be more sensitive than Lact. hilgardii 5 to the phenolic compounds studied. This work contributes to the knowledge of the effect of different phenolic compounds on the activity of wine lactic acid bacteria, which, especially in the case of aldehydes and of different molecular weight fractions of tannins, is very scarce.

Physicochemical and Antioxidant Properties of Honeys from the Sundarbans Mangrove Forest of Bangladesh.

PubMed

Islam, M Rabiul; Pervin, Tahmina; Hossain, Hemayet; Saha, Badhan; Hossain, Sheikh Julfikar

2017-12-01

This study evaluated the physicochemical, nutritional, antioxidant, and phenolic properties of ten honey samples from the Sundarbans mangrove forest, Bangladesh. The average pH, electrical conductivity, total dissolved solid, ash, moisture, hydroxymethyl furfural, titrable acidity, and absorbance were 4.3, 0.38 mS/cm, 187.5 ppm, 0.14%, 17.88%, 4.4 mg/kg, 37.7 meq/kg, and 483 mAU, respectively. In the honeys, the average contents of Ca, Cu, Fe, K, Mg, Mn, and Na were 95.5, 0.19, 6.4, 302, 39.9, 3.4, and 597 ppm, respectively, whereas Cd, Cr, Pb, and Ni were not found. The average contents of total sugar, protein, lipid, vitamin C, polyphenols, flavonoids, and anthocyanins in the honeys were 69.3%, 0.8%, 0.29%, 107.3 mg/kg, 757.2 mg gallic acid equivalent/kg, 43.1 mg chatechin equivalent/kg, and 5.4 mg/kg, respectively. The honeys had strong 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity, reducing power and total antioxidant capacity. High-performance liquid chromatography analysis of the honey fractions revealed the quantification of six polyphenols namely, (+)-catechin, (-)-epicatechin, p -caumeric acid, syringic acid, trans -cinnamic acid, and vanillic acid at 194.98, 330.34, 74.64, 218.97, 49.55, and 118.84 mg/kg, respectively. Therefore, the honeys in the Sundarbans are of excellent quality and a prospective source of polyphenols, and antioxidants.

Systematic identification and quantification of tetracyclic monoterpenoid oxindole alkaloids in Uncaria rhynchophylla and their fragmentations in Q-TOF-MS spectra.

PubMed

Xie, Shuanglu; Shi, Yuanyuan; Wang, Yixiang; Wu, Chunyong; Liu, Wenyuan; Feng, Feng; Xie, Ning

2013-01-01

Uncaria rhynchophylla (UR) is a species of Uncaria that is distributed mainly in China and Japan. In this study, the chemical constituents, including alkaloids, flavonoids, and quinic acids, in UR have been systematically identified and quantified by a developed method of high-performance liquid chromatography coupled with diode-array detection and quadrupole time-of-flight mass spectrometry (Q-TOF-MS). Tetracyclic monoterpenoid oxindole alkaloids (TMOAs) are characteristic compounds in this herb, and their fragmentations in Q-TOF-MS have been investigated. Diagnostic fragmentation ions (DFIs) were first delineated for isorhynchophylline-type (7S, C20-ethyl) and corynoxeine-type (7R, C20-vinyl) TMOAs, and these were used for identification of these alkaloids in UR. In this study, a total of 29 compounds, comprising 18 alkaloids, six flavonoids, and five quinic acids, were identified. Among them, there are four novel TMOAs, named as 22-O-β-glucopyranosyl isorhynchophyllic acid (10), 22-O-β-glucopyranosyl rhynchophyllic acid (11), 9-hydroxy isocorynoxeine (16), and 9-hydroxy corynoxeine (20), which have not been reported previously. Furthermore, eight marker compounds, namely chlorogenic acid (3), catechin (8), epicatechin (9), isocorynoxeine (24), rhynchophylline (25), isorhynchophylline (27), vincoside lactam (28), and corynoxeine (29), have been simultaneously quantified. The developed method has been validated and successfully applied to analyze three samples of UR from Jiangxi Province. The contents of the marker compounds have been detected and compared. Copyright © 2013 Elsevier B.V. All rights reserved.

Molecular binding of catechins to biomembranes:Relationship to biolgical activity

USDA-ARS?s Scientific Manuscript database

Molecular dynamics simulations were used to study the interactions of four catechins commonly found in tea with lipid bilayers of cell membranes. Experimental studies in the literature have shown that catechins are linked to beneficial health effects, specifically as they are related to interaction...

The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta-analysis

USDA-ARS?s Scientific Manuscript database

Different outcomes of the effect of catechin-caffeine mixtures and caffeine-only supplementation on energy expenditure and fat oxidation have been reported in short-term studies. Therefore, a meta-analysis was conducted to elucidate whether catechin-caffeine mixtures and caffeine-only supplementatio...

Suppressive Effects of Tea Catechins on Breast Cancer

PubMed Central

Xiang, Li-Ping; Wang, Ao; Ye, Jian-Hui; Zheng, Xin-Qiang; Polito, Curt Anthony; Lu, Jian-Liang; Li, Qing-Sheng; Liang, Yue-Rong

2016-01-01

Tea leaf (Camellia sinensis) is rich in catechins, which endow tea with various health benefits. There are more than ten catechin compounds in tea, among which epigallocatechingallate (EGCG) is the most abundant. Epidemiological studies on the association between tea consumption and the risk of breast cancer were summarized, and the inhibitory effects of tea catechins on breast cancer, with EGCG as a representative compound, were reviewed in the present paper. The controversial results regarding the role of tea in breast cancer and areas for further study were discussed. PMID:27483305

Simultaneous preparation of naturally abundant and rare catechins by tannase-mediated biotransformation combining high speed counter current chromatography.

PubMed

Xia, Guobin; Hong, Shan; Liu, Songbai

2014-05-15

Simultaneous preparation of naturally rare catechins, EGC and EC, has been realized by tannase-mediated biotransformation combining high speed counter current chromatography. In addition, simultaneous preparation of the four catechins, EGCG, ECG, EGC, and EC in green tea extract has also been achieved by HSCCC under the normal phase and the reversed phase modes. The identity of the catechins was determined by HPLC-DAD-ESI-MS and quantification of the catechins was performed by HPLC-DAD. In a typical HSCCC separation, 27.2 mg 98.8% EGCG, 14.1 mg 94.7% EGC, and 9.3 mg 97.5% EC were obtained. This new method is efficient, time-saving and valuable for biological studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Protection of brain and pancreas from high-fat diet: effects of catechin and caffeine.

PubMed

Unno, Keiko; Yamamoto, Hiroyuki; Maeda, Ken-Ichi; Takabayashi, Fumiyo; Yoshida, Hirotoshi; Kikunaga, Naomi; Takamori, Nina; Asahina, Shunsuke; Iguchi, Kazuaki; Sayama, Kazutoshi; Hoshino, Minoru

2009-02-16

To investigate the effect of a high-fat diet on brain and pancreas functions, we used SAMP10 mice that have characteristics of brain atrophy and cognitive dysfunction with aging. Simultaneously, we investigated the effect of green tea catechin consumption on high-fat diet feeding, because green tea catechin has been reported to improve brain atrophy, brain dysfunction and obesity. The body weight of mice fed a high-fat diet from 2 to 12 months was higher than that of the control, although the calorie intake was not. The high-fat diet also increased insulin secretion; however, the hypersecretion of insulin and obesity were suppressed when mice were fed a high-fat diet with green tea catechin and caffeine. Furthermore, brain atrophy was suppressed and the working memory, tested using Y-maze, improved in mice fed a high-fat diet containing green tea catechin and caffeine. The secretion of insulin might affect both obesity and brain function. A strong correlation was found between working memory and insulin release in mice fed a high-fat diet with green tea catechin and/or caffeine. The results indicate the protective effect of green tea catechin and caffeine on the functions of brain and pancreas in mice fed a high-fat diet.

Influence of roasting on the antioxidant activity and HMF formation of a cocoa bean model systems.

PubMed

Oliviero, Teresa; Capuano, Edoardo; Cämmerer, Bettina; Fogliano, Vincenzo

2009-01-14

During the roasting of cocoa beans chemical reactions lead to the formation of Maillard reaction (MR) products and to the degradation of catechin-containing compounds, which are very abundant in these seeds. To study the modifications occurring during thermal treatment of fat and antioxidant rich foods, such as cocoa, a dry model system was set up and roasted at 180 degrees C for different times. The role played in the formation of MR products and in the antioxidant activity of the system by proteins, catechin, and cocoa butter was investigated by varying the model system formulation. Results showed that the antioxidant activity decreased during roasting, paralleling catechin concentration, thus suggesting that this compound is mainly responsible for the antioxidant activity of roasted cocoa beans. Model system browning was significantly higher in the presence of catechin, which contributed to the formation of water-insoluble melanoidins, which are mainly responsible for browning. HMF concentration was higher in casein-containing systems, and its formation was strongly inhibited in the presence of catechin. No effects related to the degree of lipid oxidation could be observed. Data from model systems obtained by replacing fat with water showed a much lower rate of MR development and catechin degradation but the same inhibitory effect of catechin on HMF formation.

Insulin mimetic impact of Catechin isolated from Cassia fistula on the glucose oxidation and molecular mechanisms of glucose uptake on Streptozotocin-induced diabetic Wistar rats.

PubMed

Daisy, P; Balasubramanian, K; Rajalakshmi, M; Eliza, J; Selvaraj, J

2010-01-01

Diabetes mellitus is the most common and serious metabolic disorder among people all over the world. Many plants have successfully been used to overcome this problem. Cassia fistula, an ethnomedicnal plant, is widely used in Indian medicine to treat diabetes. Methanol extract of stem of plant, reduced the blood glucose levels in Streptozotocin-induced diabetic rats. Bioassay guided fractionation was followed to isolate Catechin from methanol extract. Catechin was administered to Streptozotocin (60mg/kg b.w.)-induced diabetic male Wistar rats at different doses (5, 10, 20mg/kg b.w.) for 6 weeks to assess its effect on fasting plasma glucose. The plasma glucose was significantly (p<0.05) reduced when compared to the control. Oral administration of Catechin (20mg/kg b.w.) markedly increased tissue glycogen, and (14)C-glucose oxidation without any change in plasma insulin and C-peptide. Catechin restored the altered Glucokinase, glucose-6 Phosphatase, Glycogen Synthase and Glycogen Phosphorylase levels to near normal. GLUT4 mRNA and protein expression were enhanced after Catechin treatment. The results of this experimental study indicated that Catechin possesses hypo-glycemic, Glucose oxidizing and insulin mimetic activities and hence it could be used as a drug for treating diabetes.

Role of catechins on ET-1 induced stimulation of PLD and NADPH oxidase activities in pulmonary smooth muscle cells: Determination of the probable mechanism by molecular docking studies.

PubMed

Chakraborti, Sajal; Sarkar, Jaganmay; Bhuyan, Rajabrata; Chakraborti, Tapati

2017-12-05

Treatment of human pulmonary artery smooth muscle cells with ET-1 stimulated PLD and NADPH oxidase activities, which were inhibited upon pretreatment with bosentan (ET-1 receptor antagonist), FIPI (PLD inhibitor), apocynin (NADPH oxidase inhibitor) and EGCG & ECG (catechins having galloyl group), but not EGC & EC (catechins devoid of galloyl group). Herein, we determined the probable mechanism by which the galloyl group containing catechins inhibit ET-1 induced stimulation of PLD activity by molecular docking analyses based on our biochemical studies. ET-1 induced stimulation of PLD activity was inhibited by SecinH3 (inhibitor of cytohesin). Arf-6 and cytohesin-1 were associated in the cell membrane, which was not inhibited by the catechins during ET-1 treatment to the cells. However, EGCG and ECG inhibited binding of GTPγS with Arf-6 even in presence of cytohesin-1. The molecular docking analyses revealed that the galloyl group containing catechins (EGCG/ECG) with cytohesin1-Arf6GDP, but not the non-galloyl-containing catechins (EGC and EC), prevents GDP/GTP exchange in Arf-6 which seems to be an important mechanism for inhibition of ET-1 induced activation of PLD and subsequently increase in NADPH oxidase activities.

Dipole moment, solution, and solid state structure (-)-epicatechin, a monomer unit of procyanidin polymers

Treesearch

Frank R. Fronczek; Garret Gannuch; Wayne L. Mattice; Fred L. Tobiason; Jeff L. Broker; Richard W. Hemingway

1984-01-01

The structure of (-)-epicatechin has been determined in the crystalline state. Crystals are orthorhombic. P212121, a=670.8(1), b=1329.1 (3), c=1426.2(4) pm, Z=4. Dc=1.516 g cm-3, R=0.041 for 1624 observations. Intramolecular hydrogen bonds are absent. The...

Anti-diarrheal activity of (-)-epicatechin from Chiranthodendron pentadactylon Larreat: experimental and computational studies.

PubMed

Velázquez, Claudia; Correa-Basurto, José; Garcia-Hernandez, Normand; Barbosa, Elizabeth; Tesoro-Cruz, Emiliano; Calzada, Samuel; Calzada, Fernando

2012-09-28

Chiranthodendron pentadactylon Larreat is frequently used in Mexican traditional medicine as well as in Guatemalan for several medicinal purposes, including their use in the control of diarrhea. This work was undertaken to obtain additional information that support the traditional use of Chiranthodendron pentadactylon Larreat, on pharmacological basis using the major antisecretory isolated compound from computational, in vitro and in vivo experiments. (-)-Epicatechin was isolated from ethyl acetate fraction of the plant crude extract. In vivo toxin (Vibrio cholera or Escherichia coli)-induced intestinal secretion in rat jejunal loops models and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis on Vibrio cholera toxin were used in experimental studies while the molecular docking technique was used to conduct computational study. The antisecretory activity of epicatechin was tested against Vibrio cholera and Escherichia coli toxins at oral dose 10 mg/kg in the rat model. It exhibited the most potent activity on Vibrio cholera toxin (56.9% of inhibition). In the case of Escherichia coli toxin its effect was moderate (24.1% of inhibition). SDS-PAGE analysis revealed that both (-)-epicatechin and Chiranthodendron pentadactylon extract interacted with the Vibrio cholera toxin at concentration from 80 μg/mL and 300 μg/mL, respectively. Computational molecular docking showed that epicatechin interacted with four amino acid residues (Asn 103, Phe 31, Phe 223 and The 78) in the catalytic site of Vibrio cholera toxin, revealing its potential binding mode at molecular level. The results derived from computational, in vitro and in vivo experiments on Vibrio cholera and Escherichia coli toxins confirm the potential of epicatechin as a new antisecretory compound and give additional scientific support to anecdotal use of Chiranthodendron pentadactylon Larreat in Mexican traditional medicine to treat gastrointestinal disorders such as diarrhea. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Grape seed and tea extracts and catechin 3-gallates are potent inhibitors of α-amylase and α-glucosidase activity.

PubMed

Yilmazer-Musa, Meltem; Griffith, Anneke M; Michels, Alexander J; Schneider, Erik; Frei, Balz

2012-09-12

This study evaluated the inhibitory effects of plant-based extracts (grape seed, green tea, and white tea) and their constituent flavan-3-ol monomers (catechins) on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. To evaluate the relative potency of extracts and catechins, their concentrations required for 50 and 90% inhibition of enzyme activity were determined and compared to the widely used pharmacological glucosidase inhibitor, acarbose. Maximum enzyme inhibition was used to assess relative inhibitory efficacy. Results showed that grape seed extract strongly inhibited both α-amylase and α-glucosidase activity, with equal and much higher potency, respectively, than acarbose. Whereas tea extracts and catechin 3-gallates were less effective inhibitors of α-amylase, they were potent inhibitors of α-glucosidase. Nongallated catechins were ineffective. The data show that plant extracts containing catechin 3-gallates, in particular epigallocatechin gallate, are potent inhibitors of α-glucosidase activity and suggest that procyanidins in grape seed extract strongly inhibit α-amylase activity.