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Sample records for acylated flavonol glycosides

  1. Acylated flavonol glycoside from Platanus orientalis.

    PubMed

    Tantry, Mudasir A; Akbar, Seema; Dar, Javid A; Irtiza, Syed; Galal, Ahmed; Khuroo, Mohammad A; Ghazanfar, Khalid

    2012-03-01

    The ethylacetate and n-butanol fractions of ethanolic extract of Platanus orientalis leaves led to the isolation of new acylated flavonol glycoside as 3',5,7-trihydroxy-4'-methoxyflavonol 3-[O-2-O-(2,4-Dihydroxy)-E-cinnamoyl-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl (1→2)]-β-D-glucopyranoside, along with seven known compounds. All the compounds were characterized by NMR including 2D NMR techniques. The isolates were evaluated for NF-κB, nitric oxide (NO), aromatase and QR2 chemoprevention activities and some of them appeared to be modestly active.

  2. Acylated flavonol glycosides from the flower of Elaeagnus angustifolia L.

    PubMed

    Bendaikha, Sarah; Gadaut, Méredith; Harakat, Dominique; Magid, Alabdul

    2014-07-01

    Seven acylated flavonol glycosides named elaeagnosides A-G, in addition to seven known flavonoids were isolated from the flowers of Elaeagnus angustifolia. Their structures were elucidated by different spectroscopic methods including 1D, 2D NMR experiments and HR-ESI-MS analysis. In order to identify natural antioxidant and tyrosinase inhibitor agents, the abilities of these flavonoids to scavenge the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and to inhibit tyrosinase activity were evaluated. Results revealed that two of these compounds had significant anti-oxidant effect and one compound showed weak tyrosinase-inhibitory activity compared with kojic acid, quercetin, or ascorbic acid, which were used as positive control.

  3. Acylated flavonol glycosides from Tagetes minuta with antibacterial activity.

    PubMed

    Shahzadi, Irum; Shah, Mohammad M

    2015-01-01

    Wild marigold (Tagetes minuta), a flowering plant of the family Asteraceae contains compounds of pharmaceutical and nutritional importance especially essential oils and flavonols. Identification, characterization of flavonols and determination of their antibacterial activity were major objectives of the current study. The isolation and purification of flavonols was accomplished using chromatographic techniques while structural elucidation was completed by LC-MS and NMR spectroscopy. The extracts and purified compounds were tested against various bacterial strains for antibacterial activity. A total of 19 flavonols were isolated from this species. Of these, 17 were of butanol and two of ethyl acetate extracts. Based on the concentration and purity, eight potential flavonols were selected and structurally elucidated. Four flavonols, 6-hydroxyquercetin 7-O-β-(6''-galloylglucopyranoside; 2), 6-hydroxykaempferol 7-O-β-glucopyranoside (5), 6-hydroxykaempferol 7-O-β-(6''-galloylglucopyranoside; 7), 6-hydroxyquercetin 7-O-β-(6''-caffeoylglucopyranoside; 9), were identified for the first time from T. minuta. Butanol and ethyl acetate extracts of flowers and seeds showed significant antibacterial activity against Micrococcus leteus, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas pikettii. Among the isolated flavonols only 1, 2, and 18 were found to possess significant antibacterial activity against M. luteus. The extracts and purified flavonols from T. minuta can be potential candidates for antibacterial drug discovery and support to ethnopharmacological use.

  4. Identification, quantification and antioxidant activity of acylated flavonol glycosides from sea buckthorn (Hippophae rhamnoides ssp. sinensis).

    PubMed

    Chen, Chu; Xu, Xue-Min; Chen, Yang; Yu, Meng-Yao; Wen, Fei-Yan; Zhang, Hao

    2013-12-01

    A novel acylated flavonol glycoside: isorhamnetin (3-O-[(6-O-E-sinapoyl)-β-D-glucopyranosyl-(1→2)]-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside) (1), together with two known acylated flavonol glycosides: quercetin (3-O-[(6-O-E-sinapoyl)-β-D-glucopyranosyl-(1→2)]-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside) (2) and kaempferol (3-O-[(6-O-E-sinapoyl)-β-D-glucopyranosyl-(1→2)]-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside) (3) were isolated from the n-butanol fraction of sea buckthorn (Hippophae rhamnoides ssp. sinensis) berries for the first time by chromatographic methods, and their structures were elucidated using UV, MS, (1)H and (13)C NMR, and 2D NMR. Compounds 1-3 showed good scavenging activities, with respective IC50 values of 8.91, 4.26 and 30.90 μM toward the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical; respective Trolox equivalent antioxidant capacities of 2.89, 4.04 and 2.44 μM μM(-1) toward 2,2'-azino-bis-3-ethyl-benzothiazoline-6-sulphonate (ABTS) radical. The quantitative analysis of the isolated acylated flavonol glycosides was performed by HPLC-DAD method. The contents of compounds 1-3 were in the range of 12.2-31.4, 4.0-25.3, 7.5-59.7 mg/100 g dried berries and 9.1-34.5, 75.1-182.1, 29.2-113.4 mg/100 g dried leaves, respectively.

  5. New Acylated Flavonol Glycosides and a Phenolic Profile of Pritzelago alpina, a Forgotten Edible Alpine Plant.

    PubMed

    Corradi, Elisabetta; De Mieri, Maria; Cadisch, Larissa; Abbet, Christian; Hamburger, Matthias; Potterat, Olivier

    2016-02-01

    Thirteen acylated flavonoid glycosides, 1-13, including eleven new congeners, 3-13, were isolated from the aerial parts of Pritzelago alpina (Brassicaceae) by a combination of column chromatography on Sephadex LH-20, and preparative and semi-preparative HPLC. The structures were established by extensive NMR and MS experiments in combination with acid hydrolysis and sugar analysis by GC/MS. The new compounds were shown to be kaempferol and quercetin glycosides acylated for most of them by a branched short chain fatty acid or a hydroxycinnamic acid residue on the sugar portion. As shown by a HPLC-DAD analysis of a MeOH extract, these compounds are the main phenolic constituents in the aerial parts of the plant.

  6. Flavonol Glycosides from Gaura Biennis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytochemical investigation of the native American plant Gaura biennis led to the isolation of three new flavonol glycosides (1-3), along with eight known ones. Their structures were established primarily by spectroscopic data as quercetin 3-O-(2"-O-a-L-rhamnopyranosyl-6"-O-E-p-coumaroyl)-ß-D- gluco...

  7. Flavonol glycosides from distilled petals of Rosa damascena Mill.

    PubMed

    Schiber, Andreas; Mihalev, Kiril; Berardini, Nicolai; Mollov, Plamen; Carle, Reinhold

    2005-01-01

    Flavonol glycosides were extracted from petals of Rosa damascena Mill. after industrial distillation for essential oil recovery and characterized by high-performance liquid chromatography-electrospray ionization mass spectrometry. Among the 22 major compounds analyzed, only kaempferol and quercetin glycosides were detected. To the best of our knowledge, the presence of quercetin 3-O-galactoside and quercetin 3-O-xyloside has so far not been reported within the genus Rosa. In addition, based on their fragmentation patterns, several acylated quercetin and kaempferol glycosides, some of them being disaccharides, were identified for the first time. The kaempferol glycosides, along with the kaempferol aglycone, accounted for 80% of the total compounds that were quantified, with kaempferol 3-O-glucoside being the predominant component. The high flavonol content of approximately 16 g/kg on a dry weight basis revealed that distilled rose petals represent a promising source of phenolic compounds which might be used as functional food ingredients, as natural antioxidants or as color enhancers.

  8. Enhanced profiling of flavonol glycosides in the fruits of sea buckthorn (Hippophae rhamnoides).

    PubMed

    Fang, Rui; Veitch, Nigel C; Kite, Geoffrey C; Porter, Elaine A; Simmonds, Monique S J

    2013-04-24

    Use of enhanced LC-MS/MS methods to identify common glycosyl groups of flavonoid glycosides enabled better characterization of the flavonoids in fruits of sea buckthorn (Hippophae rhamnoides). The saccharide moieties of 48 flavonol O-glycosides detected in a methanol extract were identified by these methods. Several of the flavonol glycosides were acylated, two of which were isolated and found to be new compounds. Their structures were determined using spectroscopic and chemical methods as isorhamnetin 3-O-(6-O-E-sinapoyl-β-D-glucopyranosyl)-(1→2)-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside (24) and isorhamnetin 3-O-(6-O-E-feruloyl-β-D-glucopyranosyl)-(1→2)-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside (30). Analysis of the acylated glycosyl groups of 24 and 30 by serial mass spectrometry provided evidence to suggest the acylation position of 11 other minor flavonol glycosides acylated with hydroxycinnamic or hydroxybenzoic acids. The nitric oxide scavenging activities of 24 and 30 were compared with those of other flavonoids and with ascorbic acid and the potassium salt of 2-(4-carboxyphenyl)-4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazolyl-1-oxy-3-oxide (carboxy-PTIO).

  9. New flavonol glycosides from the leaves of Caragana brachyantha.

    PubMed

    Perveen, Shagufta; Al-Taweel, Areej Mohammad; Al-Musayeib, Nawal; Fawzy, Ghada Ahmed; Khan, Afsar; Mehmood, Rashad; Malik, Abdul

    2015-01-01

    Two new flavonol glycosides, brachysides C and D, together with three known flavonol glycosides, were isolated from the leaves of Caragana brachyantha. The structures of brachysides C and D were elucidated on the basis of detailed spectroscopic analysis as quercetin 5-O-[α-L-rhamnopyranosyl-(1 → 6)-β-D-glucopyranoside]-7-O-[α-L-rhamnopyranoside] and quercetin 5-O-[α-L-rhamnopyranosyl-(1 → 6)-β-D-glucopyranoside]-7-O-[α-L-rhamnopyranoside]-4'-O-[α-L-rhamnopyranoside], respectively. The presence of flavonol tetra- and triglycosides bearing a sugar moiety at position 5 was the first report from this genus Caragana.

  10. Three new flavonol glycosides from Suaeda maritima.

    PubMed

    Abd El-Latif, Rasha R; Mansour, Ragaa M A; Sharaf, Mohamed; Farag, Ahmad

    2014-01-01

    Three new flavonol glycosides isolated from the 70% methanol extract of Suaeda maritima (Chenopodiaceae) were characterized based on spectroscopic and chemical methods as quercetin 3-O-α-l-rhamnopyranosyl(1″' → 6″)-β-d-galactopyranoside-7-O-β-d-glucopyranosyl(1″″' → 2″″)-glucopyranoside, kaempferol 3-O-α-l-rhamnopyranosyl(1″' → 6″)-β-d-galactopyranoside-7-O-β-d-glucopyranosyl(1″″' → 2″″)-glucopyranoside, and kaempferol 3-O-α-l-rhamnopyranosyl(1″' → 6″)-β-d-galactopyranoside-7-O-(2″″'-O-trans-feruloyl)-β-d-glucopyranosyl-(1″″' → 2″″)-β-d-glucopyranoside. In addition, four known compounds, namely, quercetin and kaempferol, methyl cis, trans-ferulate, and methyl trans-ferulate were identified. The plant extract and these compounds showed cytotoxic activity against the human tumor cell lines MCF7, HCT116, and HEPG2.

  11. Antioxidant flavonol glycosides from Schinus molle.

    PubMed

    Marzouk, Mohamed S; Moharram, Fatma A; Haggag, Eman G; Ibrahim, Magda T; Badary, Osama A

    2006-03-01

    Chromatographic separation of aqueous MeOH extract of the leaves of Schinus molle L. has yielded two new acylated quercetin glycosides, named isoquercitrin 6''-O-p-hydroxybenzoate (12) and 2''-O-alpha-L-rhamnopyranosyl-hyperin 6''-O-gallate (13), together with 12 known polyphenolic metabolites for the first time from this species, namely gallic acid (1), methyl gallate (2), chlorogenic acid (3), 2''-alpha-L-rhamnopyranosyl-hyperin (4), quercetin 3-O-beta-D-neohesperidoside (5), miquelianin (6), quercetin 3-O-beta-D-galacturonopyranoside (7), isoquercitrin (8), hyperin (9), isoquercitrin 6''-gallate (10), hyperin 6''-O-gallate (11) and (+)-catechin (14). Their structures were established on the basis of chromatographic properties, chemical, spectroscopic (UV, 1H, 13C NMR) and ESI-MS (positive and negative modes) analyses. Compounds 4-9 and 11 exhibited moderate to strong radical scavenging properties on lipid peroxidation, hydroxyl radical and superoxide anion generations with the highest activities shown by 6 and 7 in comparison with that of quercetin as a positive control in vitro.

  12. Malonylated flavonol glycosides from the petals of Clitoria ternatea.

    PubMed

    Kazuma, Kohei; Noda, Naonobu; Suzuki, Masahiko

    2003-01-01

    Three flavonol glycosides, kaempferol 3-O-(2"-O-alpha-rhamnosyl-6"-O-malonyl)-beta-glucoside, quercetin 3-O-(2"-O-alpha-rhamnosyl-6"-O-malonyl)-beta-glucoside, and myricetin 3-O-(2",6"-di-O-alpha-rhamnosyl)-beta-glucoside were isolated from the petals of Clitoria ternatea cv. Double Blue, together with eleven known flavonol glycosides. Their structures were identified using UV, MS, and NMR spectroscopy. They were characterized as kaempferol and quercetin 3-(2(G)- rhamnosylrutinoside)s, kaempferol, quercetin, and myricetin 3-neohesperidosides, 3-rutinosides, and 3-glucosides in the same tissue. In addition, the presence of myricetin 3-O-(2"-O-alpha-rhamnosyl-6"-O-malonyl)-beta-glucoside was inferred from LC/MS/MS data for crude petal extracts. The flavonol compounds identified in the petals of C. ternatea differed from those reported in previous studies.

  13. Antioxidant activities and structural characterization of flavonol O-glycosides from seeds of Japanese horse chestnut (Aesculus turbinata BLUME).

    PubMed

    Kimura, Hideto; Ogawa, Satoshi; Ishihara, Tomoe; Maruoka, Mahoko; Tokuyama-Nakai, Shota; Jisaka, Mitsuo; Yokota, Kazushige

    2017-08-01

    We attempted to evaluate the contents and distribution of antioxidants in the whole seeds, seed shells, and peeled seeds of the Japanese horse chestnut. The seed shells exhibited the highest antioxidant activities due to the presence of highly polymeric proanthocyanidins as we have reported recently. On the other hand, the peeled seeds predominantly contained flavonols such as quercetin and kaempferol at a high level of 66.7% of total polyphenols, also contributing to the predominant antioxidant activities. The instrumental analysis of the extract from the whole seeds revealed the identification of eight flavonol O-glycosides, including six compounds with quercetin and two species with kaempferol as aglycones. The isolated species exhibited different antioxidant activities depending on the types of aglycones, glycosides, and acylated moieties. The results indicate that the peeled seeds are a good source of flavonol O-glycosides serving as antioxidants to be used for food additives and dietary supplements.

  14. Two new flavonol glycosides from Gymnema sylvestre and Euphorbia ebracteolata.

    PubMed

    Liu, Xin; Ye, Wencai; Yu, Biao; Zhao, Shouxun; Wu, Houming; Che, Chuntao

    2004-03-15

    Two new flavonol glycosides, namely kaempferol 3-O-beta-D-glucopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-galactopyranoside (1) and quercetin 3-O-6"-(3-hydroxyl-3-methylglutaryl)-beta-D-glucopyranoside (2), have been isolated from the aerial parts of Gymnema sylvestre and Euphorbia ebracteolata, respectively. Their structures were determined on the basis of chemical and spectroscopic methods.

  15. Acylated pregnane glycosides from Caralluma russeliana.

    PubMed

    Abdel-Sattar, Essam; Ahmed, Ahmed A; Hegazy, Mohamed-Elamir F; Farag, Mohamed A; Al-Yahya, Mohammad Abdul-Aziz

    2007-05-01

    The chloroform extract of the aerial parts of Caralluma russeliana yielded four acylated pregnane glycosides, namely russeliosides E-H, three were found now. The structures of the compounds were elucidated using MS, 1H NMR, 13C NMR, 1H-1H COSY, HMQC, NOESY and HMBC experiments.

  16. Flavonol glycosides in the petal of Rosa species as chemotaxonomic markers.

    PubMed

    Sarangowa, Ochir; Kanazawa, Tsutomu; Nishizawa, Makoto; Myoda, Takao; Bai, Changxi; Yamagishi, Takashi

    2014-11-01

    Thirteen flavonol glycosides were isolated from the petals of Rosa species belonging to the section Gallicanae, and their structures were identified from their spectroscopic data. These flavonol glycosides, along with two flavonol glycosides isolated from Rosa rugosa, in the petals of 31 Rosa species belonging to sections Gallicanae, Cinnamomeae, Caninae, and Synstylae were quantitatively analyzed by UPLC. The results indicated that the species belonging to these sections could be classified into four types (Type A, B, C and D) based on the pattern of flavonol glycoside contents, whereas the R. rugosa flavonol glycosides were detected only in section Cinnamomeae. A principal components analysis (PCA) calculated from the 15 flavonol glycosides contained in these samples supported the presence of four types. The distribution of the species in Type D (a group of Cinnamomeae) was shown to reflect close interrelationships, but species in Type B (one group of Gallicanae) could be subdivided into two groups, one of which contained species in section Synstylae. Moreover, the flavonol glycosides were grouped by sugar moieties: a disaccharide composed of two hexoses (S1), a hexose (S2), including a hexose with galloyl group, a pentose (S3), and a disaccharide composed of a hexose and a pentose (S4). The ratios of the amounts of S1-S4 to total flavonol glycoside content indicated that differences among the four sections were more distinctive than the amounts of the 15 flavonol glycosides. The 31 samples were divided into Type B, composed of one type of Gallicanae and Synstylae, Type A+C, composed of another type of Gallicanae and Caninae, and Type D, composed of Cinnamomeae. The R. rugosa flavonol glycosides were shown to be important chemotaxonomic markers for the classification of species in Cinnamomeae, and this method of using flavonol glycosides as chemotaxonomic markers could be useful for the identification of Rosa species belonging to sections Gallicanae, Cinnamomeae

  17. Determination of catechins and flavonol glycosides in Chinese tea varieties.

    PubMed

    Wu, Chunyan; Xu, Hairong; Héritier, Julien; Andlauer, Wilfried

    2012-05-01

    A standardised profiling method based on high performance liquid chromatography combined with ultraviolet (UV) and mass spectrometric detection (MS) was established to analyse the phenolic compounds of selected tea varieties used for manufacturing of green, black and oolong teas. The composition and content of 24 tea constituents were analysed, including catechins, flavonol and flavones glycosides, phenolic acids and purine alkaloids. Each tea variety had a unique chemical profile. The compositions of catechins were lower in the tea varieties for green tea manufacturing, while the content of myricetin glycosides was the lowest in the tea variety for oolong tea manufacturing. The content of individual phenolic compounds in the selected tea varieties is highly variable. However, the content of total catechins is proposed to be helpful to classify tea according to the future application as non fermented green and fermented oolong or black tea.

  18. Quantification of flavonol glycosides in Camellia sinensis by MRM mode of UPLC-QQQ-MS/MS.

    PubMed

    Wu, Yahui; Jiang, Xiaolan; Zhang, Shuxiang; Dai, Xinlong; Liu, Yajun; Tan, Huarong; Gao, Liping; Xia, Tao

    2016-04-01

    Phenolic compounds are major components of tea flavour, in which catechins and flavonol glycosides play important roles in the astringent taste of tea infusion. However, the flavonol glycosides are difficult to quantify because of the large variety, as well as the inefficient seperation on chromatography. In this paper, a total of 15 flavonol glycosides in the tea plant (Camellia sinensis) were identified by the high performance liquid chromatography (HPLC) coupled to a time-of-flight mass spectrometer (TOF-MS), and a quantitative method was established based on multiple reaction monitoring (MRM) mode of ultra-high performance liquid chromatography (UPLC) coupled to a triple quadrupole mass spectrometer (QQQ-MS/MS). It provided the limit of detection and quantification to the order of picogram, which was more sensitive than the HPLC detection of the order of nanogram. The relative standard deviations of the intra- and inter-day variations in retention time and signal intensity (peak area) of six analytes were less than 0.26% and 4%, respectively. The flavonol glycosides of four tea cultivars were relatively quantified using the signal intensity (peak area) of product ion, in which six flavonol glycosides were quantified by the authentic standards. The results showed that the flavonol mono-, di- and tri-glycoside mostly accumulated in young leaves of the four tea cultivars. Notably, the myricetin 3-O-galactoside was the major component among the six flavonol glycosides detected.

  19. A new flavonol glycoside from the medicinal halophyte Suaeda fruticosa.

    PubMed

    Oueslati, Samia; Ksouri, Riadh; Pichette, André; Lavoie, Serge; Girard-Lalancette, Karl; Mshvildadze, Vakhtang; Abdelly, Chedly; Legault, Jean

    2014-01-01

    A new flavonol glycoside, namely 3-(α-rhamnopyranosyl-(1 → 2)-[β-xylopyranosyl-(1 → 6)]-β-glucopyranosyloxy) isorhamnetin was reported from methanol extracts of aerial parts of Suaeda fruticosa for the first time. In this work, liquid chromatography coupled to atmospheric pressure chemical ionisation mass spectrometry, high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy were used to identify this new compound. Structure was elucidated on the basis of extensive spectroscopic analysis, including HSQC, HMBC and (1)H-(1)H COSY. Antioxidant potentialities of a pure compound were evaluated. The estimation of antioxidant capacities using oxygen radical absorbance capacity (ORAC method) and a cell based-assay (WS1) indicated that this new flavonol exhibited the highest antioxidant activities with an ORAC value of 5.0 ± 0.3 μmol Trolox/μmol and inhibited the tBH-induced oxidation of 2',7'-dichlorofluorescin with an IC50 value of 4.9 ± 0.6 μM.

  20. Analysis of supercooling-facilitating (anti-ice nucleation) activity of flavonol glycosides.

    PubMed

    Kasuga, Jun; Fukushi, Yukiharu; Kuwabara, Chikako; Wang, Donghui; Nishioka, Atsushi; Fujikawa, Emiko; Arakawa, Keita; Fujikawa, Seizo

    2010-04-01

    Deep supercooling xylem parenchyma cells (XPCs) of katsura tree (Cercidiphyllum japonicum) contain four kinds of flavonol glycosides with high supercooling-facilitating (anti-ice nucleation) activities. These flavonol glycosides have very similar structures, but their supercooling-facilitating activities are very different. In this study, we analyzed the supercooling-facilitating activities of 12 kinds of flavonol glycosides in order to determine the chemical structures that might affect supercooling-facilitating activity. All of the flavonol glycosides tested showed supercooling-facilitating activity, although the magnitudes of activity differed among the compounds. It was clear that the combination of the position of attachment of the glycosyl moiety, the kind of attached glycosyl moiety and the structure of aglycone determined the magnitude of anti-ice nucleation activity. However, there is still some ambiguity preventing the exact identification of features that affect the magnitude of supercooling-facilitating activity.

  1. Acylated pregnane glycosides from Caralluma quadrangula.

    PubMed

    Abdallah, Hossam M; Osman, Abdel-Moneim M; Almehdar, Hussein; Abdel-Sattar, Essam

    2013-04-01

    In a previous study, the methanolic extract as well as the chloroform fraction of the aerial parts of Caralluma quadrangula (Forssk.) N.E.Br. indigenous to Saudi Arabia showed significant in vitro cytotoxic activity against breast cancer (MCF7) cell line. In a biologically-guided fractionation approach, four acylated pregnane glycosides were isolated from the chloroform fraction of C. quadrangula. The structures of the isolated compounds were elucidated by the analysis of their MS and NMR data. The compounds were identified as 12,20-di-O-benzoylboucerin 3-O-β-D-digitoxopyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (1), 12,20-di-O-benzoylboucerin 3-O-β-D-cymaropyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (2), 12,20-di-O-benzoylboucerin 3-O-β-D-glucopyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (3) and 12,20-di-O-benzoyl-3β,5α,12β,14β,20-pentahydroxy-(20R)-pregn-6-ene 3-O-β-D-glucopyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (4). The isolated compounds were tested for their cytotoxic activity against breast cancer (MCF7) cell line.

  2. HPLC-MSn identification and quantification of flavonol glycosides in 28 wild and cultivated berry species.

    PubMed

    Mikulic-Petkovsek, Maja; Slatnar, Ana; Stampar, Franci; Veberic, Robert

    2012-12-15

    Berries and red fruits are rich dietary sources of polyphenols with reported health benefits. More than 50 different flavonols (glycosides of quercetin, myricetin, kaempferol, isorhamnetin, syringetin and laricitrin) have been detected and quantified with HPLC-MS(n) in fruits of blueberry, bilberry, cranberry, lingonberry, eastern shadbush, Japanese wineberry, black mulberry, chokeberry, red, black and white currants, jostaberry, red and white gooseberry, hardy kiwifruit, goji berry, rowan, dog rose, Chinese and midland hawthorn, wild and cultivated species of blackberry, raspberry, strawberry and elderberry. The phenolic constituents and contents varied considerably among the analyzed berry species. Elderberry contained the highest amount of total flavonols (450-568 mgkg(-1) FW), followed by berry species, containing more than 200 mgkg(-1) FW of total: chokeberry (267mgkg(-1)), eastern shadbush (261 mgkg(-1)), wild grown blackberry (260 mgkg(-1)), rowanberry (232 mgkg(-1)), american cranberry (213 mgkg(-1)) and blackcurrants (204 mgkg(-1)). Strawberry (10.5 mgkg(-1)) and white currants (4.5 mgkg(-1)) contained the lowest amount of total flavonols. Quercetins represent the highest percentage (46-100%) among flavonols in most analyzed berries. In wild strawberry and gooseberry the prevailing flavonols belong to the group of isorhamnetins (50-62%) and kaempferols, which represent the major part of flavonols in currants (49-66%). Myricetin glycosides could only be detected in chokeberry, rowanberry and species from the Grossulariaceae, and Adoxaceae family and Vaccinium genus. Wild strawberry and blackberry contained from 3- to 5-fold higher total flavonols than the cultivated one.

  3. DPPH radical scavenging activity of two flavonol glycosides from Aconitum napellus sp. lusitanicum.

    PubMed

    Luis, J C; Valdés, F; Martín, R; Carmona, A J; Díaz, Jesús G

    2006-09-01

    The DPPH radical scavenging activity of two flavonol glycosides obtained from ethanolic extracts of Aconitum napellus sp. lusitanicum was studied. The results showed a high DPPH antiradical activity of compound 1 (quercetin 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranosyl-7-O-alpha-rhamnopyranoside) when compared with compound 2 (quercetin-3-sophoroside-7-rhamnopyranoside), rutin and ascorbic acid. The relationship between the caffeoyl and rhamnopyranoside groups in the flavonol glycosides structures and the DPPH antiradical activity was also discussed.

  4. Flavonol glycosides and steroidal saponins from the leaves of Cestrum nocturnum and their cytotoxicity.

    PubMed

    Mimaki, Y; Watanabe, K; Ando, Y; Sakuma, C; Sashida, Y; Furuya, S; Sakagami, H

    2001-01-01

    Phytochemical analysis of the leaves of Cestrum nocturnum (Solanaceae) resulted in the isolation of two new flavonol glycosides (1, 2) and seven steroidal saponins (3-9), including four new ones (4, 6, 7, and 9). The structures of the new compounds were determined by spectroscopic analysis, including 2D NMR data, and the results of hydrolytic cleavage. Cytotoxic activities of the isolated compounds against human oral squamous cell carcinoma-(HSC-2) cells and normal human gingival fibroblasts are reported.

  5. Systematic identification of flavonols, flavonol glycosides, triterpene and siraitic acid glycosides from Siraitia grosvenorii using high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry combined with a screening strategy.

    PubMed

    Qing, Zhi-Xing; Zhao, Huan; Tang, Qi; Mo, Chang-Ming; Huang, Peng; Cheng, Pi; Yang, Peng; Yang, Xue-Yi; Liu, Xiu-Bin; Zheng, Ya-Jie; Zeng, Jian-Guo

    2017-05-10

    The fruits of Siraitia grosvenorii are considered to be health-promoting because of the diversity of their bioactive ingredients. In the present study, a screening method, using high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (HPLC-Q-TOF-MS) combined with a screening strategy, has been established. The technology was used to systematically screening the targeted metabolites, primarily from the complex matrix of S. grosvenorii. The compounds were then identified by their exact masses and characteristic fragment ions, in comparison with the fragmentation behaviors of 19 references. Finally, 122 compounds, including 53 flavonols and flavonol glycosides, 59 triterpene glycosides and 10 siraitic acid glycosides, were screened and identified in 10-, 50- and 80-day fruits, roots, stems and leaves of S. grosvenorii. 98 of them were reported for the first time. Additionally, the distribution of all identified components in different parts of the plant was determined and metabolic networks for flavonol and triterpene glycosides were proposed.

  6. Acylated pregnane glycosides from Caralluma sinaica.

    PubMed

    Al-Massarani, Shaza M; Bertrand, Samuel; Nievergelt, Andreas; El-Shafae, Azza M; Al-Howiriny, Tawfeq A; Al-Musayeib, Nawal M; Cuendet, Muriel; Wolfender, Jean-Luc

    2012-07-01

    Caralluma sinaica is sold on local markets of Saudi Arabia for various health benefits however no phytochemical study has specifically been performed on this species. NMR and UHPLC-ESI-TOF-MS profilings of the ethanolic extract of the whole plant reveal a very complex phytochemical composition dominated by pregnanes. Detailed information on its constituents was obtained after isolation. Six pregnane glycosides were obtained and characterized based on the extensive spectroscopic analysis (including IR, ¹H NMR, ¹³C NMR and MS data), in addition to ten known compounds (seven pregnanes and three flavonoids). The compounds were identified as 12β-O-benzoyl-20-O-acetyl boucerin-3-O-6-deoxy-3-O-methyl-β-D-glucopyranosyl-(1-->4)-β-D-cymaropyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-O-tigloyl-20-O-acetyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-O-benzoyl-20-O-acetyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-β-D-digitalopyranosyl-(1-->4)-β-D-cymaropyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-O-benzoyl-20-O-acetyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-hevetopyranosyl-(1-->4)-β-D-cymaropyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-O-benzoyl-20-O-tigloyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-20-O-dibenzoyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-β-D-cymaropyranosyl-(1-->4)-β-D-cymaropyranoside. Finally, the isolated compounds were evaluated for their quinone reductase induction.

  7. A new flavonol glycoside from the florets of Carthamus tinctorius L.

    PubMed

    Xie, Xue; Zhou, Jianming; Sun, Lin; Zhang, Hongda; Zhao, Yiwu; Song, Yaling; Wang, Xuejing; Ni, Fuyong; Huang, Wenzhe; Wang, Zhenzhong; Xiao, Wei

    2016-01-01

    One new flavonol glycoside, 6-hydroxykaempferol-3-O-β-D-glucoside-7-O-β-D-glucuronide (1), together with eight known flavonoids and three known quinochalcones, was isolated from the florets of Carthamus tinctorius L. Their structures were determined by extensive spectroscopic analyses. Their cardioprotective effects against H2O2-induced apoptosis in H9c2 cells were also evaluated; compounds 1, 2, 4-5, 7-10 and 12 provided significant protective effects on H2O2-induced H9c2 cells at the concentration of 25 μg/mL.

  8. Anti-inflammatory activity of a novel flavonol glycoside from the Bauhinia variegata Linn.

    PubMed

    Yadava, R N; Reddy, V Madhu Sudhan

    2003-06-01

    Bauhinia variegata Linn. (Leguminosae) is commonly known as 'Kachnar' in Hindi. It is distributed almost throught India. Its powdered bark is traditionally used for tonic, astrain, ulcers. It is also useful in skin diseases. The roots are used as antidote to snake poison. The present article deals with the isolation and structural elucidation of a novel flavonol glycoside 5,7,3',4'-tetrahydroxy-3-methoxy-7-O-alpha-L-rhamnopyranosyl(1-->3)-O-beta-galactopyranoside (1) from the roots of Bauhinia Variegata and its structure was identified by spectral analysis and chemical degradations. The novel compound (1) showed anti-inflammatory activity.

  9. Acylated quercetagetin glycosides with antioxidant activity from Tagetes maxima.

    PubMed

    Parejo, Irene; Bastida, Jaume; Viladomat, Francesc; Codina, Carles

    2005-10-01

    The fractionation of a methanolic extract of Tagetes maxima guided for antioxidant activity resulted in the isolation of three acylated quercetagetin glycosides, quercetagetin-7-O-(6-O-caffeoyl-beta-D-glucopyranoside), quercetagetin-7-O-(6-O-p-coumaroyl-beta-D-glucopyranoside) and quercetagetin-7-O-(6-O-galloyl-beta-D-glucopyranoside), as well as four known flavonoid glycosides. The structural elucidation was accomplished by spectroscopic methods (ESI-MS/MS and NMR). The antioxidant activity of fractions and isolated compounds was determined by checking the scavenging activity against three different radicals: 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH*), hydroxyl (*OH), and superoxide (O2*-). The three isolated compounds exhibited a high radical scavenging activity in comparison with reference compounds.

  10. A general approach to quantification of hydroxycinnamic acid derivatives and flavones, flavonols, and their glycosides by UV spectrophotometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A general method was developed for the quantification of hydroxycinnamic acid derivatives and flavones, flavonols, and their glycosides based on the UV molar relative response factors (MRRF) of the standards. Each of these phenolic compounds contains a cinnamoyl structure and has a maximum absorban...

  11. Flavonol glycosides of sea buckthorn (Hippophaë rhamnoides ssp. sinensis) and lingonberry (Vaccinium vitis-idaea) are bioavailable in humans and monoglucuronidated for excretion.

    PubMed

    Lehtonen, Henna-Maria; Lehtinen, Outi; Suomela, Jukka-Pekka; Viitanen, Matti; Kallio, Heikki

    2010-01-13

    Glucuronidation and excretion of sea buckthorn and lingonberry flavonols were investigated in a postprandial trial by analyzing the intact forms of flavonol glycosides as well as glucuronides in plasma, urine, and feces. Four study subjects consumed sea buckthorn (study day 1) and lingonberry (study day 2) breakfasts, and blood, urine, and fecal samples were collected for 8, 24, and 48 h, respectively. Both glycosides and glucuronides of the flavonol quercetin as well as kaempferol glucuronides were detected in urine and plasma samples after the consumption of lingonberries; 14% of flavonols in urine were glycosides, and 86% were glucuronidated forms (wt %). After the consumption of sea buckthorn, 5% of flavonols excreted in urine were detected intact, and 95% as the glucuronides (wt %). Solely glucuronides of flavonols isorhamnetin and quercetin were found in plasma after the consumption of sea buckthorn berries. Only glycosides were detected in the feces after each berry trial. Flavonol glycosides and glucuronides remained in blood and urine quite long, and the peak concentrations appeared slightly later than previously described. The berries seemed to serve as a good flavonol supply, providing steady flavonol input for the body for a relatively long time.

  12. [Determination of flavonol glycosides in tea samples by ultra-high performance liquid chromatography-photodiode array detection-tandem mass spectrometry].

    PubMed

    Wang, Zhicong; Sha, Yuebing; Yu, Xiaobo; Liang, Yuerong

    2015-09-01

    An ultra-high performance liquid chromatography-photodiode array detection-tandem mass spectrometry (UPLC-PDA-MS/MS) method was developed for the determination of flavonol glycosides in tea samples. The chromatographic separation was performed on an UPLC HSS T3 column by gradient elution with the mobile phases of acetonitrile and water both containing 0.1% (v/v) formic acid. A total of 15 flavonol glycosides which include 3 myricetin glycosides, 6 quercetin glycosides and 6 kaempferol glycosides were positively identified in green and black tea samples by comparing the retention times and mass spectra of the samples with standards and publications. The quantities of flavonol glycosides were relatively calculated with the stand- ard quercetin-3-rhamnosylglucoside (Q-GRh) which was calibrated with external quantification method using multi-reaction monitoring (MRM) mode. The results showed that there were different flavonol glycoside distributions in green tea and black tea. The total amount of flavonol glycosides in green tea was 1. 7 times of that in black tea. The major flavonol glycosides in green tea were myricetin-3-galactoside (M-Ga), myricetin-3-glucoside (M-G), quercetin-3-glucosyl-rhamnosyl-galactoside (Q-GaRhG), quercetin-3-glucosyl-rhamnosyl-glucoside (Q-GRhG), kaempferol-3-glucosyl-rhamnosyl-galactoside (K-GaRhG) and kaempferol-3-glucosyl- rhamnosyl-glucoside (K-GRhG), but for black tea, the major flavonol glycosides were quercetin-3-rhamnosylglucoside (Q-GRh), quercetin-3-glucoside (Q-G), kaempferol-3-rhamnosylglucoside (K-GRh) and kaempferol-3-galactoside (K-Ga). The present method is accurate, convenient for the rapid identification of flavonol glycosides and analysis of constituent distribution for green and black teas.

  13. Acylated flavonol tri- and tetraglycosides in the flavonoid metabolome of Cladrastis kentukea (Leguminosae).

    PubMed

    Kite, Geoffrey C; Rowe, Emily R; Lewis, Gwilym P; Veitch, Nigel C

    2011-04-01

    The foliar metabolome of Cladrastis kentukea (Leguminosae) contains a complex mixture of flavonoids including acylated derivatives of the 3-O-rhamnosyl(1→2)[rhamnosyl(1→6)]-galactosides of kaempferol and quercetin and their 7-O-rhamnosides, together with an array of non-acylated kaempferol and quercetin di-, tri- and tetraglycosides. Thirteen of the acylated flavonoids, 12 of which had not been reported previously, were characterised by spectroscopic and chemical methods. Eight of these were the four isomers of kaempferol 3-O-α-l-rhamnopyranosyl(1→2)[α-l-rhamnopyranosyl(1→6)]-(3/4-O-E/Z-p-coumaroyl-β-d-galactopyranoside) and their 7-O-α-l-rhamnopyranosides, and three were isomers of quercetin 3-O-α-l-rhamnopyranosyl(1→2)[α-l-rhamnopyranosyl(1→6)]-(3/4-O-E/Z-p-coumaroyl-β-d-galactopyranoside) - the remaining 4Z isomer was identified by LC-UV-MS analysis of a crude extract. The final two acylated flavonoids characterised by NMR were the 3E and 4E isomers of kaempferol 3-O-α-l-rhamnopyranosyl(1→2)[α-l-rhamnopyranosyl(1→6)]-(3/4-O-E-feruloyl-β-d-galactopyranoside)-7-O-α-l-rhamnopyranoside while the 3Z and 4Z isomers were again detected by LC-UV-MS. Using the observed fragmentation behaviour of the isolated compounds following a variety of MS experiments, a further 18 acylated flavonoids were given tentative structures by LC-MS analysis of a crude extract. Acylated flavonoids were absent from the flowers of C. kentukea, which contained an array of non-acylated kaempferol and quercetin glycosides. Immature fruits contained kaempferol 3-O-α-rhamnopyranosyl(1→2)[α-rhamnopyranosyl(1→6)]-β-galactopyranoside and its 7-O-α-rhamnopyranoside as the major flavonoids with acylated flavonoids, different from those in the leaves, only present as minor constituents. The presence of acylated flavonoids distinguishes the foliar flavonoid metabolome of C. kentukea from that of a closely related legume, Styphnolobium japonicum, which contains a similar

  14. New flavonol glycosides from the flowers of Aconitum napellus ssp. tauricum.

    PubMed

    Fico, G; Braca, A; Bilia, A R; Tomè, F; Morelli, I

    2001-04-01

    From the methanolic extract of the flowers of A. napellus spp. tauricum four new flavonol glycosides: quercetin 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7- O-alpha-rhamnopyranoside (1), kaempferol 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta- glucopyranoside-7-O-alpha-rhamnopyranoside (2), quercetin 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta- glucopyranoside-7-O-alpha-rhamnopyranoside (3), and kaempferol 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta- glucopyranoside-7-O-alpha-rhamnopyranoside (4), together with the known beta-3,4-dihydroxyphenethyl beta-glucopyranoside were isolated. The structural elucidation of all compounds was deduced on the basis of 1H- and 13C-NMR spectral data, including those derived from 2D-NMR, as well as on HPLC-MS results.

  15. New flavonol glycoside from Scabiosa prolifera L. aerial parts with in vitro antioxidant and cytotoxic activities.

    PubMed

    Al-Qudah, Mahmoud A; Otoom, Noor K; Al-Jaber, Hala I; Saleh, Ayman M; Abu Zarga, Musa H; Afifi, Fatma U; Abu Orabi, Sultan T

    2017-03-24

    Phytochemical investigation of the chemical constituents of the aerial parts of Scabiosa prolifera L. led to the isolation of one new flavonol glycoside, kaempferol-3-O-(4″,6″-di-E-p-coumaroyl)-β-D-galactopyranoside (1), along with ten other known compounds including luteolin-7-O-(2″-O-ethyl-β-glucopyranoside), β-sitosterol, β-sitosterylglucoside, ursolic acid, corosolic acid, ursolic acid 3-O-β-D-arabinopyranoside, apigenin, methyl-α-D-glucopyranoside, luteolin-7-O-β-glucopyranoside and isoorientin. The structures of all isolated compounds were established using chemical methods and spectroscopic methods including IR, UV, NMR (1D and 2D) and HRESIMS. All compounds were isolated for the first time from the plant. The antioxidant and cytotoxic activities of compounds 1 and 2 were also investigated.

  16. Rapid identification of acylated flavonol tetraglycosides in oolong teas using HPLC-MSn.

    PubMed

    Dou, Jianpeng; Lee, Viola S Y; Tzen, Jason T C; Lee, Maw-Rong

    2008-01-01

    A method was developed to separate and identify acylated flavonol tetraglycosides (AFTGs) by combining isocratic HPLC with electrospray ionisation tandem mass spectrometry. Better separation was obtained for oolong tea infusion using a manually packed Sephadex LH-20 mini-column than with an ACCUBOND ODS solid-phase column. Seven unknown and one known AFTGs were found in oolong teas prepared by various semi-fermentation processes and their structures were identified by mass spectrometry. According to the analyses of diverse oolong teas including Dongding Oolong, Tieguanyin, Wuyi Oolong, Fenghuang Oolong, Gaoshan Shibi, Laocong Shuixian and Baihao Oolong, AFTGs seemed to be universally present, and each oolong tea could be classified into one of three groups (Dongding Oolong, Tieguanyin and Wuyi Oolong) on the basis of its AFTGs profile. The results suggest that the developed method is rapid and sensitive for identifying natural compounds.

  17. Change of supercooling capability in solutions containing different kinds of ice nucleators by flavonol glycosides from deep supercooling xylem parenchyma cells in trees.

    PubMed

    Kuwabara, Chikako; Kasuga, Jun; Wang, Donghui; Fukushi, Yukiharu; Arakawa, Keita; Koyama, Toshie; Inada, Takaaki; Fujikawa, Seizo

    2011-12-01

    Deep supercooling xylem parenchyma cells (XPCs) in Katsura tree contain flavonol glycosides with high supercooling-facilitating capability in solutions containing the ice nucleation bacterium (INB) Erwinia ananas, which is thought to have an important role in deep supercooling of XPCs. The present study, in order to further clarify the roles of these flavonol glycosides in deep supercooling of XPCs, the effects of these supercooling-facilitating (anti-ice nucleating) flavonol glycosides, kaempferol 3-O-β-D-glucopyranoside (K3Glc), kaempferol 7-O-β-D-glucopyranoside (K7Glc) and quercetin 3-O-β-D-glucopyranoside (Q3Glc), in buffered Milli-Q water (BMQW) containing different kinds of ice nucleators, including INB Xanthomonas campestris, silver iodide and phloroglucinol, were examined by a droplet freezing assay. The results showed that all of the flavonol glycosides promoted supercooling in all solutions containing different kinds of ice nucleators, although the magnitudes of supercooling capability of each flavonol glycoside changed in solutions containing different kinds of ice nucleators. On the other hand, these flavonol glycosides exhibited complicated nucleating reactions in BMQW, which did not contain identified ice nucleators but contained only unidentified airborne impurities. Q3Glc exhibited both supercooling-facilitating and ice nucleating capabilities depending on the concentrations in such water. Both K3Glc and K7Glc exhibited only ice nucleation capability in such water. It was also shown by an emulsion freezing assay in BMQW that K3Glc and Q3Glc had no effect on homogeneous ice nucleation temperature, whereas K7Glc increased ice nucleation temperature. The results indicated that each flavonol glycoside affected ice nucleation by very complicated and varied reactions. More studies are necessary to determine the exact roles of these flavonol glycosides in deep supercooling of XPCs in which unidentified heterogeneous ice nucleators may exist.

  18. Flavonol glycosides in berries of two major subspecies of sea buckthorn (Hippophaë rhamnoides L.) and influence of growth sites.

    PubMed

    Ma, Xueying; Laaksonen, Oskar; Zheng, Jie; Yang, Wei; Trépanier, Martin; Kallio, Heikki; Yang, Baoru

    2016-06-01

    Flavonol glycosides of wild sea buckthorn (Hippophaë rhamnoides ssp. sinensis) berries from China and cultivated berries (H. rhamnoides ssp. mongolica) from Finland and Canada were identified and quantified. Twenty-six flavonol glycosides were found with isorhamnetin and quercetin as the major aglycones. The contents of flavonol glycosides ranged 23-250 mg/100 g fresh berries and were significantly higher in the berries of ssp. sinensis than in those of ssp. mongolica. Among the cultivars of ssp. mongolica, the berries of 'Oranzhevaya' had the lowest (23 mg/100 g) content, and those of 'Prevoshodnaya' the highest content of flavonol glycosides (80 mg/100 g). Within the ssp. mongolica, the samples from Kittilä (Northern Finland) had higher levels of most flavonol glycosides than those from Turku (Southern Finland) and Québec. Among the ssp. sinensis berries of different growth sites, increasing trends were detected in the contents of most of the compounds as the altitude increased and as the latitude decreased. The wild berries (ssp. sinensis) from Sichuan had remarkably high contents and unique profiles of flavonol glycosides.

  19. Low and moderate photosynthetically active radiation affects the flavonol glycosides and hydroxycinnamic acid derivatives in kale (Brassica oleracea var. sabellica) dependent on two low temperatures.

    PubMed

    Neugart, Susanne; Fiol, Michaela; Schreiner, Monika; Rohn, Sascha; Zrenner, Rita; Kroh, Lothar W; Krumbein, Angelika

    2013-11-01

    Kale (Brassica oleracea var. sabellica) contains a large number of naturally occurring structurally different non-acylated and acylated flavonol glycosides as well as hydroxycinnamic acid derivatives. The objective of this study was to determine the effect of low and moderate photosynthetic active radiation (PAR) and how these levels interact with low temperature in these phenolic compounds. Juvenile kale plants were treated with PAR levels from 200 to 800 μmol m(-2) s(-1) at 5 and 10 °C under defined conditions in climate chambers. Of the investigated 20 compounds, 11 and 17 compounds were influenced by PAR and temperature, respectively. In addition, an interaction between PAR and temperature was found for eight compounds. The response of the phenolic compounds to PAR was structure-dependent. While quercetin triglycosides increased with higher PAR at 5 and 10 °C, the kaempferol triglycosides exhibited the highest concentrations at 400 μmol m(-2) s(-1). In contrast, kaempferol diglycosides exhibited the highest concentrations at increased PAR levels of 600 and 800 μmol m(-2) s(-1) at 10 °C. However, key genes of flavonol biosynthesis were influenced by temperature but remained unaffected by PAR. Furthermore, there was no interaction between the PAR level and the low temperature in the response of hydroxycinnamic acid derivatives in kale with the exception of caffeoylquinic acid, which decreased with higher PAR levels of 600 and 800 μmol m(-2) s(-1) and at a lower temperature. In conclusion, PAR and its interaction with temperature could be a suitable tool for modifying the profile of phenolic compounds.

  20. Flavonol Glycosides in Currant Leaves and Variation with Growth Season, Growth Location, and Leaf Position.

    PubMed

    Yang, Wei; Alanne, Aino-Liisa; Liu, Pengzhan; Kallio, Heikki; Yang, Baoru

    2015-10-28

    Flavonol glycosides (FG) were analyzed in the leaves of six currant cultivars (Ribes spp.) with HPLC-DAD, HPLC-MS/MS, and NMR. The average amounts of the 12 major, identified FG constituted 86-93% (9.6-14.1 mg/g DW) of the total of 27 FG found. Quercetin and kaempferol were the major aglycones with trace amounts of myricetin. Quercetin-3-O-(2,6-α-dirhamnopyranosyl-β-glucopyranoside), quercetin-3-O-(2-β-xylopyranosyl-6-α-rhamnopyranosyl-β-glucopyranoside), and kaempferol-3-O-(3,6-α-dirhamnopyranosyl-β-glucopyranoside) were identified for the first time in currant leaves and existed in a white currant cultivar 'White Dutch' only. Kaempferol-3-O-β-(6'-malonyl)glucopyranoside was also a new compound existing in abundance in five cultivars but not in the white one. The results show the primary importance of the genetic background of the cultivars. The content of malonylated FG of special importance in cardiovascular health decreased regularly during summer. Time of collection and leaf position were more prominent factors affecting the composition than were the year of harvest or the growth latitude. Randomly collected leaves differed in their FG profiles from those collected from the middle position of new branches.

  1. A new proline-containing flavonol glycoside from Caragana leucophloea Pojark.

    PubMed

    Luo, Chao; Wang, Ali; Wang, Xiaohan; Li, Jing; Liu, Hongwei; Wang, Mingan; Wang, Lan; Lai, Daowan; Zhou, Ligang

    2015-01-01

    One new proline-containing flavonol glycoside, namely kaempferol-3-O-methyl-7-O-β-D-glucopyranosyl-8-(1-methyleneproline)-4'-O-β-D-glucopyranoside (1), together with 15 known flavonoids, 3-O-methylkaempferol (2), 3-O-methylquercetin (3), quercetin (4), kaempferol (5), apigenin (6), rhamnazin (7), astragalin (8), alquds (9), quercitrin (10), rutin (11), isoquercitrin (12), apigetrin (13), myricitrin (14), hesperidin (15) and calycosin-7-O-β-D-glucopyranoside (16) were isolated from the aerial parts of Caragana leucophloea Pojark. (Leguminosae). Their structures were determined on the basis of spectroscopic analyses and by comparison with literature data. Compounds 2-4 revealed a strong antimicrobial activity with minimum inhibitory concentration values of 12.5-150 μg/mL and median inhibitory concentration (IC50) values of 7.42-76.61 μg/mL. Compounds 3, 4, 6-8, 10-12 and 14 showed strong antioxidant activity. Compounds 2-7 exhibited moderate antinematodal activity on Caenorhabditis elegans with IC50 values of 40.51-68.05 μg/mL.

  2. Flavonol glycosides and other phenolic compounds in buds and leaves of different varieties of black currant (Ribes nigrum L.) and changes during growing season.

    PubMed

    Liu, Pengzhan; Kallio, Heikki; Yang, Baoru

    2014-10-01

    Phenolic compounds in buds and leaves of three varieties of black currant in Finland were identified by HPLC-DAD-ESI-MS/MS. Forty-three phenolic compounds of flavonol glycosides, proanthocyanidins and phenolic acids were found in variety "Mikael" whereas only thirty-five in "Mortti" and "Jaloste n:o 15". Glycosides of quercetin and kaempferol were the major phenolics. Rutin, hyperoside, isoquercitrin, kaempferol-3-O-rutinoise, kaempferol-3-O-glucoside, quercetin-3-O-(6″-malonyl)-glucoside and a kaempferol-malonylhexoside were the most abundant flavonol glycosides. The contents of flavonol glycosides ranged from 1 to 7 mg/g fresh weight in leaves showing typically an increasing trend from July to August, reaching the highest values in early October in "Mikael" and the end of August in "Mortti" and "Jaloste n:o 15". This is the first systematic report of the composition and content of phenolic compounds in buds and leaves of black currant.

  3. A new flavonol glycoside and biological activities of Adenanthera pavonina L. leaves.

    PubMed

    Mohammed, R S; Abou Zeid, A H; El-Kashoury, E A; Sleem, A A; Waly, D A

    2014-01-01

    Adenanthera pavonina is a plant belonging to family Fabaceae. The 95% ethanol extract (EtOH) of the dried powdered leaves of the plant and successive extracts with solvents of increasing polarities were prepared. Fractionation of the successive aqueous EtOH extract on polyamide column and purification of the isolated compounds on Sephadex LH20 led to the isolation of a new methoxy flavonol glycoside named as quercetin 3-O-α-dirhamnopyranosyl-(1‴ → 2″,1″″ → 6″)-β-glucopyranoside-4'-methoxy (1), as well as kaempferol-3-O-α-dirhamnopyranosyl-(1‴ → 2″,1″″ → 6″)-β-glucopyranoside (2), isovitexin (3), quercetin-3-O-rhamnopyranosyl(1‴ → 4″)-β-glucopyranoside (4), quercetin-3-O-β-glucopranoside-4'-O-rhamnopyranoside (5), kaempferol-3-O-α-rhamnopyranosyl(1‴ → 2″)-β-glucopyranoside (6), quercetin-3-O-rhamnopyranosyl(1‴ → 2″)-β-glucopyranoside (7), quercetin-3-O-β-glucopyranoside (8), kaempferol (9) and quercetin (10). Structures of the isolated compounds were established by spectroscopic analysis. Antioxidant activities of EtOH extract, successive extracts and compounds 1 and 2 were evaluated. The ethyl acetate (EtOAc) extract and EtOH extract showed 62.67% and 49.30% free radical scavenging activity, respectively. Cytotoxic activities of the EtOH extract and compounds (1) and (2) were evaluated. The EtOH extract showed a significant cytotoxic activity against Hep G-2 (IC50 = 2.50 μg) as compared with cisplatin (IC50>10 μg).

  4. Improved cryopreservation by diluted vitrification solution with supercooling-facilitating flavonol glycoside.

    PubMed

    Kami, Daisuke; Kasuga, Jun; Arakawa, Keita; Fujikawa, Seizo

    2008-12-01

    The effect of kaempferol-7-O-glucoside (KF7G), one of the supercooling-facilitating flavonol glycosides which was originally found in deep supercooling xylem parenchyma cells of the katsura tree and was found to exhibit the highest level of supercooling-facilitating activity among reported substances, was examined for successful cryopreservation by vitrification procedures, with the aim of determining the possibility of using diluted vitrification solution (VS) to reduce cryoprotectant toxicity and also to inhibit nucleation at practical cooling and rewarming by the effect of supplemental KF7G. Examination was performed using shoot apices of cranberry and plant vitrification solution 2 (PVS2) with dilution. Vitrification procedures using the original concentration (100%) of PVS2 caused serious injury during treatment with PVS2 and resulted in no regrowth after cooling and rewarming (cryopreservation). Dilution of the concentration of PVS2 to 75% or 50% (with the same proportions of constituents) significantly reduced injury by PVS2 treatment, but regrowth was poor after cryopreservation. It is thought that dilution of PVS2 reduced injury by cryoprotectant toxicity, but such dilution caused nucleation during cooling and/or rewarming, resulting in poor survival. On the other hand, addition of 0.5mg/ml (0.05% w/v) KF7G to the diluted PVS2 resulted in significantly (p<0.05) higher regrowth rates after cryopreservation. It is thought that addition of supercooling-facilitating KF7G induced vitrification even in diluted PVS2 probably due to inhibition of ice nucleation during cooling and rewarming and consequently resulted in higher regrowth. The results of the present study indicate the possibility that concentrations of routinely used VSs can be reduced by adding supercooling-facilitating KF7G, by which more successful cryopreservation might be achieved for a wide variety of biological materials.

  5. Identification of flavonol and xanthone glycosides from mango (Mangifera indica L. Cv. "Tommy Atkins") peels by high-performance liquid chromatography-electrospray ionization mass spectrometry.

    PubMed

    Schieber, Andreas; Berardini, Nicolai; Carle, Reinhold

    2003-08-13

    Flavonol O- and xanthone C-glycosides were extracted from mango (Mangifera indica L. cv. "Tommy Atkins") peels and characterized by high-performance liquid chromatography-electrospray ionization mass spectrometry. Among the fourteen compounds analyzed, seven quercetin O-glycosides, one kaempferol O-glycoside, and four xanthone C-glycosides were found. On the basis of their fragmentation pattern, the latter were identified as mangiferin and isomangiferin and their respective galloyl derivatives. A flavonol hexoside with m/z 477 was tentatively identified as a rhamnetin glycoside, which to the best of our knowledge, has not yet been reported in mango peels. The results obtained in the present study confirm that peels originating from mango fruit processing are a promising source of phenolic compounds that might be recovered and used as natural antioxidants or functional food ingredients.

  6. Novel flavonol glycosides from the aerial parts of lentil (Lens culinaris).

    PubMed

    Żuchowski, Jerzy; Pecio, Łukasz; Stochmal, Anna

    2014-11-06

    While the phytochemical composition of lentil (Lens culinaris) seeds is well described in scientific literature, there is very little available data about secondary metabolites from lentil leaves and stems. Our research reveals that the aerial parts of lentil are a rich source of flavonoids. Six kaempferol and twelve quercetin glycosides were isolated, their structures were elucidated using NMR spectroscopy and chemical methods. This group includes 16 compounds which have not been previously described in the scientific literature: quercetin 3-O-β-D-glucopyranosyl(1→2)-β-D-galactopyranoside-7-O-β-D-glucuropyranoside (1), kaempferol 3-O-β-D-glucopyranosyl(1→2)-β-D-galacto-pyranoside-7-O-β-D-glucuropyranoside (3), their derivatives 4-10,12-15,17,18 acylated with caffeic, p-coumaric, ferulic, or 3,4,5-trihydroxycinnamic acid and kaempferol 3-O-{[(6-O-E-p-coumaroyl)-β-D-glucopyranosyl(1→2)]-α-L-rhamnopyranosyl(1→6)}-β-D-galactopyranoside-7-O-α-L-rhamnopyranoside (11). Their DPPH scavenging activity was also evaluated. This is probably the first detailed description of flavonoids from the aerial parts of lentil.

  7. [Flavonol glycosides of leaves and fruits of dill (Anethum graveolens L.). II. Phenolics of spices (author's transl)].

    PubMed

    Teuber, H; Herrmann, K

    1978-08-30

    From the leaves of dill (Anethum graveolens L.) ten flavonol glycosides have been isolated by means of polyamide, paper and thin-layer chromatography and could be identified by the usual procedures. The two major flavonoids, quercetin 3-O-beta-D-glucuronide and isorhamnetin 3-O-beta-D-glucuronide, were obtained crystalline. The minor components were found to be the 3-glucosides, 3-galactosides and 3-rhamnoglucosides of quercetin and isorhamnetin. Two other 3-glycosides of quercetin and isorhamnetin occur with the component sugars galactose, xylose, and arabinose. Besides these there are probably other two flavonoids present in trace amounts. In addition, the fruits of dill contain kaempferol 3-glucuronide as main component thought this component is completely absent in leaves.--This is probably the first time that isorhamnetin 3-O-beta-D-glucuronide has been obtained crystalline from a plant.

  8. Antioxidant and free radical scavenging activity of flavonol glycosides from different Aconitum species.

    PubMed

    Braca, Alessandra; Fico, Gelsomina; Morelli, Ivano; De Simone, Francesco; Tomè, Franca; De Tommasi, Nunziatina

    2003-05-01

    Bioassay-guided fractionation by 1,1-diphenyl-2-dipicrylhydrazyl (DPPH) radical scavenging test of polar extracts of some Italian Aconitum species (A. napellus subsp. tauricum, A. napellus subsp. neomontanum, A. paniculatum, A. vulparia) led to the isolation of 13 flavonol glycosides: quercetin 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (1), kaempferol 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (2), quercetin 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (3), kaempferol 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (4), quercetin 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (5), kaempferol 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (6), kaempferol 7-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (7), kaempferol 3-O-beta-(2"-acetyl)galactopyranoside (8), kaempferol 3-O-beta-(2"-acetyl)galactopyranoside-7-O-alpha-arabinopyranoside (9), quercetin 3-O-beta-(2"-acetyl)galactopyranoside-7-O-alpha-arabinopyranoside (10), quercetin 3,7-di-O-alpha-rhamnopyranoside (11), kaempferol 3,7-di-O-alpha-rhamnopyranoside (12) and quercetin 3-O-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (13). Their antioxidant activity (AA) was determined by measuring free radical scavenging activity by DPPH test and the coupled oxidation of beta-carotene and linoleic acid assay. The results showed that 5 is the most active compound in the DPPH free-radical scavenging test (IC(50) 1.9 microM) while in the coupled oxidation of beta-carotene and linoleic acid assay compound 1 has the highest inhibitory ratio after 1h (58.9%). Some structure-activity relationships on the AA were obtained.

  9. Comparative analyses of total phenols, antioxidant activity, and flavonol glycoside profile of cladode flours from different varieties of Opuntia spp.

    PubMed

    Santos-Zea, Liliana; Gutierrez-Uribe, Janet A; Serna-Saldivar, Sergio O

    2011-07-13

    The phenolic, flavonoid, and antioxidant contents of methanol extracts of nine samples of Mexican cactus ( Opuntia spp.) cladodes processed into flours were studied. Opuntia undulata contained the highest amount of phenols [905.08 ± 64.51 μg of gallic acid equivalents (GAE)/g]. The oxygen radical absorbance capacity (ORAC) of the cladode flour extracts indicated that Opuntia robusta var. Gavia [738.8 ± 89.9 μmol of Trolox equivalents (TE)/g] contained the highest antioxidant capacity. ORAC values significantly correlated to total phenols but not to flavonoid contents and were comparable to cranberries and blackberries. Glycosidic forms of isorhamnetin and kaempferol were identified via high-performance liquid chromatography-photodiode array (HPLC-PDA) and HPLC-mass spectrometry (MS), with isorhamnetin being the most abundant flavonol in all samples, except for Opuntia lindheimeri . The effectiveness of acid hydrolysis varied among species because of the different flavonol profiles. For some varieties, the triglycosidic forms were partially acid-hydrolyzed, giving an increase in the content of diglycosides. Optimization of hydrolysis for each species is required to estimate the total amount of each flavonol.

  10. Determination of flavonol glycosides in green tea, oolong tea and black tea by UHPLC compared to HPLC.

    PubMed

    Jiang, Heyuan; Engelhardt, Ulrich H; Thräne, Claudia; Maiwald, Beate; Stark, Janina

    2015-09-15

    An UHPLC method for the determination of flavonol glycosides (FOG) from green and oolong tea vs. black tea has been developed for the first time. Sample clean-up method by means of polyamide column chromatography was optimized with multiple-step elution. Using UHPLC and HPLC with gradient elution and photodiode array detection, eighteen FOG compounds were determined with the aid of electrospray tandem mass spectrometry. These FOG compounds were qualified on both UHPLC and HPLC, and this UHPLC method successfully separated rutin (quercetin-3-O-rutinoside) and K-grg (kaempferol-3-O-glucorhamnoglucoside) while conventional HPLC method did not. The total amounts of FOG compounds in the tea samples were 2.32-5.67g/kg dry weight (calculated as aglycones), and there is no significant difference for the total FOG content among green tea, oolong tea and black tea. However, kaempferol glycosides are more abundant in green teas, while oolong tea has more quercetin and myricetin glycosides. In black tea quercetin glycosides were most abundant.

  11. Influence of Light and Temperature on Gene Expression Leading to Accumulation of Specific Flavonol Glycosides and Hydroxycinnamic Acid Derivatives in Kale (Brassica oleracea var. sabellica).

    PubMed

    Neugart, Susanne; Krumbein, Angelika; Zrenner, Rita

    2016-01-01

    Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plants were grown either at 400 μmol m(-2) s(-1) or 100 μmol m(-2) s(-1) at 10°C, or at 400 μmol m(-2) s(-1) with 5 or 15°C. The higher light intensity overall increased flavonol content of leaves, favoring the main quercetin glycosides, a caffeic acid monoacylated kaempferol triglycoside, and disinapoyl-gentiobiose. The higher temperature mainly increased the hydroxycinnamic acid derivative disinapoyl-gentiobiose, while at lower temperature synthesis is in favor of very complex sinapic acid acylated flavonol tetraglycosides such as kaempferol-3-O-sinapoyl-sophoroside-7-O-diglucoside. A global analysis of light and temperature dependent alterations of gene expression in B. oleracea var. sabellica leaves was performed with the most comprehensive Brassica microarray. When compared to the light experiment much less genes were differentially expressed in kale leaves grown at 5 or 15°C. A structured evaluation of differentially expressed genes revealed the expected enrichment in the functional categories of e.g. protein degradation at different light intensities or phytohormone metabolism at different temperature. Genes of the secondary metabolism namely phenylpropanoids are significantly enriched with both treatments. Thus, the genome of B. oleracea was screened for predicted genes putatively involved in the biosynthesis of flavonoids and hydroxycinnamic acid derivatives. All identified B. oleracea genes were analyzed for their most specific 60-mer oligonucleotides present on the

  12. Influence of Light and Temperature on Gene Expression Leading to Accumulation of Specific Flavonol Glycosides and Hydroxycinnamic Acid Derivatives in Kale (Brassica oleracea var. sabellica)

    PubMed Central

    Neugart, Susanne; Krumbein, Angelika; Zrenner, Rita

    2016-01-01

    Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plants were grown either at 400 μmol m−2 s−1 or 100 μmol m−2 s−1 at 10°C, or at 400 μmol m−2 s−1 with 5 or 15°C. The higher light intensity overall increased flavonol content of leaves, favoring the main quercetin glycosides, a caffeic acid monoacylated kaempferol triglycoside, and disinapoyl-gentiobiose. The higher temperature mainly increased the hydroxycinnamic acid derivative disinapoyl-gentiobiose, while at lower temperature synthesis is in favor of very complex sinapic acid acylated flavonol tetraglycosides such as kaempferol-3-O-sinapoyl-sophoroside-7-O-diglucoside. A global analysis of light and temperature dependent alterations of gene expression in B. oleracea var. sabellica leaves was performed with the most comprehensive Brassica microarray. When compared to the light experiment much less genes were differentially expressed in kale leaves grown at 5 or 15°C. A structured evaluation of differentially expressed genes revealed the expected enrichment in the functional categories of e.g. protein degradation at different light intensities or phytohormone metabolism at different temperature. Genes of the secondary metabolism namely phenylpropanoids are significantly enriched with both treatments. Thus, the genome of B. oleracea was screened for predicted genes putatively involved in the biosynthesis of flavonoids and hydroxycinnamic acid derivatives. All identified B. oleracea genes were analyzed for their most specific 60-mer oligonucleotides present on the

  13. Identification of complex, naturally occurring flavonoid glycosides in kale (Brassica oleracea var. sabellica) by high-performance liquid chromatography diode-array detection/electrospray ionization multi-stage mass spectrometry.

    PubMed

    Schmidt, Susanne; Zietz, Michaela; Schreiner, Monika; Rohn, Sascha; Kroh, Lothar W; Krumbein, Angelika

    2010-07-30

    Kale is a member of the Brassicaceae family and has a complex profile of flavonoid glycosides. Therefore, kale is a suitable matrix to discuss in a comprehensive study the different fragmentation patterns of flavonoid glycosides. The wide variety of glycosylation and acylation patterns determines the health-promoting effects of these glycosides. The aim of this study is to investigate the naturally occurring flavonoids in kale. A total of 71 flavonoid glycosides of quercetin, kaempferol and isorhamnetin were identified using a high-performance liquid chromatography diode-array detection/electrospray ionization multi-stage mass spectrometry (HPLC-DAD/ESI-MS(n)) method. Of these 71 flavonol glycosides, 27 were non-acylated, 30 were monoacylated and 14 were diacylated. Non-acylated flavonol glycosides were present as mono-, di-, tri- and tetraglycosides. This is the first time that the occurrence of four different fragmentation patterns of non-acylated flavonol triglycosides has been reported in one matrix simultaneously. In addition, 44 flavonol glycosides were acylated with p-coumaric, caffeic, ferulic, hydroxyferulic or sinapic acid. While monoacylated glycosides existed as di-, tri- and tetraglycosides, diacylated glycosides occurred as tetra- and pentaglycosides. To the best of our knowledge, 28 compounds in kale are reported here for the first time. These include three acylated isorhamnetin glycosides (isorhamnetin-3-O-sinapoyl-sophoroside-7-O-D-glucoside, isorhamnetin-3-O-feruloyl-sophoroside-7-O-diglucoside and isorhamnetin-3-O-disinapoyl-triglucoside-7-O-diglucoside) and seven non-acylated isorhamnetin glycosides.

  14. Acylated pregnane glycosides from Caralluma tuberculata and their antiparasitic activity.

    PubMed

    Abdel-Sattar, Essam; Harraz, Fathalla M; Al-ansari, Soliman Mohammed Abdullah; El-Mekkawy, Sahar; Ichino, Chikara; Kiyohara, Hiroaki; Ishiyama, Aki; Otoguro, Kazuhiko; Omura, Satoshi; Yamada, Haruki

    2008-08-01

    Five pregnane glycosides were isolated from Caralluma tuberculata (1-5), in addition to a known one (russelioside E, 6). The structures of the isolated compounds were elucidated by the analysis of NMR data and FAB-MS experiments. All the isolated compounds were tested for their antimalarial and antitrypanosomal activities as well as their cytotoxicity against human diploid embryonic cell line (MRC5).

  15. UHPLC-PDA-ESI/HRMS/MSn analysis of anthocyanins, flavonol glycosides, and hydroxycinnamic acid derivatives in red mustard green (Brassica juncea (L) Coss variety)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An UHPLC-PDA-ESI/HRMS/MSn profiling method was used for a comprehensive study of the polyphenols in red mustard greens and identified 209 phenolic compounds: 67 anthocyanin, 102 flavonol glycosides, and 40 hydroxycinnamic acid derivatives. The glycosylation patterns of the flavonoids were assigned ...

  16. Identification of new flavonol O-glycosides from indigo (Polygonum tinctorium Lour) leaves and their inhibitory activity against 3-hydroxy-3-methylglutaryl-CoA reductase.

    PubMed

    Kimura, Hideto; Tokuyama, Shota; Ishihara, Tomoe; Ogawa, Satoshi; Yokota, Kazushige

    2015-04-10

    Indigo plant (Polygonum tinctorium Lour) has been utilized as a medicinal plant with a variety of biological activities. We have recently detected higher levels of flavonoids in indigo leaves. This study was undertaken to conduct the simultaneous analysis of those flavonoids using total extracts from indigo leaves by ultra-performance liquid chromatography-electrospray ionization-time-of-flight/mass spectrometry(E) (UPLC-ESI-TOF/MS(E)). The analysis by UPLC-ESI-TOF/MS(E) allowed us to determine 11 peaks of flavonoid species. The chemical structures of these compounds were identified as flavonol O-glycosides with different types of aglycones by the combination of spectroscopic and chemical methods. The predominant compounds were flavonol O-glycosides with 3,5,4'-trihydroxy-6,7-methylenedioxyflavone as an aglycone. Of these, three compounds were elucidated as new compounds. All the isolated flavonol O-glycosides exhibited the inhibitory activity against 3-hydroxy-3-methylglutaryl-CoA reductase in a dose-dependent manner with different potencies. Taken together, our results suggest the potential usefulness of the major flavonol O-glycosides from indigo leaves in controlling cholesterol biosynthesis.

  17. Inhibition of dipeptidyl peptidase activity by flavonol glycosides of guava (Psidium guajava L.): a key to the beneficial effects of guava in type II diabetes mellitus.

    PubMed

    Eidenberger, Thomas; Selg, Manuel; Krennhuber, Klaus

    2013-09-01

    Based on the traditional use in popular medicine, the effect of extracts from Psidium guajava L. leaves and of the main flavonol-glycoside components on dipeptidyl-peptidase IV (DP-IV), a key enzyme of blood glucose homoeostasis, has been investigated in-vitro. An ethanolic extract was prepared from dried, powdered leaves of guava and was found to contain seven main flavonol-glycosides, which were isolated by semipreparative HPLC and tested individually. The ethanolic guava leave extract was shown to exert a dose-dependent inhibition of DP-IV, with an IC50 of 380 μg/ml test assay solution. Also the individual flavonol-glycosides inhibited DP-IV dose-dependently, with variations of the effects by a factor of 10, and an overall effect accounting for 100% of that observed for the total guava extract. The recovery of individual flavonol-glycosides in CaCo-2 epithelial cells, a model of gastrointestinal tract absorption, amounted to 2.3-5.3% of the amount available for absorption over 60 min at 37°C.

  18. Two new flavonol glycosides and a metabolite profile of Bryophyllum pinnatum, a phytotherapeutic used in obstetrics and gynaecology.

    PubMed

    Fürer, Karin; Raith, Melanie; Brenneisen, Rudolf; Mennet, Monica; Simões-Wüst, Ana Paula; von Mandach, Ursula; Hamburger, Matthias; Potterat, Olivier

    2013-11-01

    Bryophyllum pinnatum is a succulent perennial plant native to Madagascar which is used in anthroposophical medicine to treat psychiatric disorders and as a tocolytic agent to prevent premature labour. We performed a metabolite profiling study in order to obtain a comprehensive picture of the constituents in B. pinnatum leaves and to identify chromatographic markers for quality control and safety assessment of medicinal preparations. Preliminary HPLC-PDA-ESIMS analyses revealed that flavonoid glycosides were the main UV-absorbing constituents in the MeOH extract of B. pinnatum. Two phenolic glucosides, syringic acid β-D-glucopyranosyl ester (1) and 4'-O-β-D-glucopyranosyl-cis-p-coumaric acid (2), as well as nine flavonoids (3-11) including kaempferol, quercetin, myricetin, acacetin, and diosmetin glycosides were unambiguously identified by 1H and 2D NMR analysis after isolation from a MeOH extract. The flavonol glycosides quercetin 3-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranoside 7-O-β-D-glucopyranoside (3) and myricetin 3-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranoside (4) were new natural products. With the aid of HPLC-PDA-APCIMS and authentic references isolated from the related species B. daigremontianum, the presence of four bufadienolides, bersaldegenin-1-acetate (12), bryophyllin A (13), bersaldegenin-3-acetate (14), and bersaldegenin-1,3,5-orthoacetate (15) was detected in B. pinnatum.

  19. Natural variation in flavonol accumulation in Arabidopsis is determined by the flavonol glucosyltransferase BGLU6

    PubMed Central

    Ishihara, Hirofumi; Tohge, Takayuki; Viehöver, Prisca; Fernie, Alisdair R.; Weisshaar, Bernd; Stracke, Ralf

    2016-01-01

    Flavonols are colourless secondary metabolites, primarily regarded as UV-protection pigments that are deposited in plants in their glycosylated forms. The glycosylation of flavonols is mainly catalysed by UDP-sugar-dependent glycosyltransferases (UGTs). Although the structures of flavonol glycosides accumulating in Arabidopsis thaliana are known, many genes involved in the flavonol glycosylation pathway are yet to be discovered. The flavonol glycoside profiles of seedlings from 81 naturally occurring A. thaliana accessions were screened using high performance thin layer chromatography. A qualitative variation in flavonol 3-O-gentiobioside 7-O-rhamnoside (F3GG7R) content was identified. Ler × Col-0 recombinant inbred line mapping and whole genome association mapping led to the identification of a glycoside hydrolase family 1-type gene, At1g60270/BGLU6, that encodes a homolog of acyl-glucose-dependent glucosyltransferases involved in the glycosylation of anthocyanins, possibly localized in the cytoplasm, and that is co-expressed with genes linked to phenylpropanoid biosynthesis. A causal single nucleotide polymorphism introducing a premature stop codon in non-producer accessions was found to be absent in the producers. Several other naturally occurring loss-of-function alleles were also identified. Two independent bglu6 T-DNA insertion mutants from the producer accessions showed loss of F3GG7R. Furthermore, bglu6 mutant lines complemented with the genomic Ler BGLU6 gene confirmed that BGLU6 is essential for production of F3GGR7. We have thus identified an accession-specific gene that causes a qualitative difference in flavonol glycoside accumulation in A. thaliana strains. This gene encodes a flavonol 3-O-glucoside: 6″-O-glucosyltransferase that does not belong to the large canonical family of flavonol glycosyltransferases that use UDP-conjugates as the activated sugar donor substrate. PMID:26717955

  20. Functional Differentiation of the Glycosyltransferases That Contribute to the Chemical Diversity of Bioactive Flavonol Glycosides in Grapevines (Vitis vinifera)[W][OA

    PubMed Central

    Ono, Eiichiro; Homma, Yu; Horikawa, Manabu; Kunikane-Doi, Satoshi; Imai, Haruna; Takahashi, Seiji; Kawai, Yosuke; Ishiguro, Masaji; Fukui, Yuko; Nakayama, Toru

    2010-01-01

    We identified two glycosyltransferases that contribute to the structural diversification of flavonol glycosides in grapevine (Vitis vinifera): glycosyltransferase 5 (Vv GT5) and Vv GT6. Biochemical analyses showed that Vv GT5 is a UDP-glucuronic acid:flavonol-3-O-glucuronosyltransferase (GAT), and Vv GT6 is a bifunctional UDP-glucose/UDP-galactose:flavonol-3-O-glucosyltransferase/galactosyltransferase. The Vv GT5 and Vv GT6 genes have very high sequence similarity (91%) and are located in tandem on chromosome 11, suggesting that one of these genes arose from the other by gene duplication. Both of these enzymes were expressed in accordance with flavonol synthase gene expression and flavonoid distribution patterns in this plant, corroborating their significance in flavonol glycoside biosynthesis. The determinant of the specificity of Vv GT5 for UDP-glucuronic acid was found to be Arg-140, which corresponded to none of the determinants previously identified for other plant GATs in primary structures, providing another example of convergent evolution of plant GAT. We also analyzed the determinants of the sugar donor specificity of Vv GT6. Gln-373 and Pro-19 were found to play important roles in the bifunctional specificity of the enzyme. The results presented here suggest that the sugar donor specificities of these Vv GTs could be determined by a limited number of amino acid substitutions in the primary structures of protein duplicates, illustrating the plasticity of plant glycosyltransferases in acquiring new sugar donor specificities. PMID:20693356

  1. Acylated pelargonidin glycosides in the red-purple flowers of Pharbitis nil.

    PubMed

    Lu, T S; Saito, N; Yokoi, M; Shigihara, A; Honda, T

    1992-01-01

    Four acylated pelargonidin glycosides and pelargonidin 3-sophoroside-5-glucoside were isolated from 23 red-purple cultivars of Pharbitis nil. The acylated anthocyanins were all based on pelargonidin 3-sophoroside-5-glucoside and were identified as the 3-O-[2-O-(beta-D-glucopyranosyl)-6-O-(trans-caffeyl)-beta-D- glucopyranoside]-5-O-(beta-D-glucopyranoside), the 3-O-[2-O-(6-O-(trans-3-O-(beta-D-glucopyranosyl)caffeyl)-beta- D-glucopyranosyl)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), the 3-O-[2-O-(6-O-(trans-3-O-(beta-D-glucopyranosyl)caffeyl)-beta- D-glucopyranosyl)-6-O-(trans-caffeyl)-beta-D-glucopyranoside]-5-O-(beta- D-glucopyranoside); and the 3-O-[2-O-(6-O-(trans-3-O-(beta-D-glucopyranosyl)caffeyl)-beta-D- glucopyranosyl)-6-O-(trans-4-O-(6-O-(trans-3-O-(beta-D- glucopyranosyl)caffeyl)- beta-D-glucopyranosyl)caffeyl)-beta-D-glucopyranoside]-5-O-(beta-D- glucopyranoside). By the analysis of these anthocyanin constituents variously in 23 cultivars, it was found that the red flower colour gradually changed into more bluish colour with increasing numbers of caffeic acid residues in the acylated pelargonidin glycosides. The stabilities of these anthocyanins increased in the order of increasing caffeyl substitution.

  2. Acylated flavone glycosides from the roots of Saussurea lappa and their antifungal activity.

    PubMed

    Rao, Kolisetty Sambasiva; Babu, Goriparthi Venu; Ramnareddy, Yemireddy Venkata

    2007-03-07

    The isolation of four novel acylated flavonoid glycosides from the roots of Saussurea lappa and their identification using a combination of 1D and 2D NMR and mass spectrometry is described. The in vitro antifungal and antibacterial activities of the isolated compounds and their mixture were tested on nine fungal and four bacterial strains, using the microdilution method. The compounds and mixture showed moderate to high antifungal activity against most of the fungi tested, compared to a miconazole standard, while only one compound and the mixture showed antibacterial activity against all strains tested.

  3. A new acylated quercetin glycoside from the leaves of Stevia rebaudiana Bertoni.

    PubMed

    Li, Jun; Jiang, Hua; Shi, Renbing

    2009-01-01

    A new acylated quercetin glycoside quercetin-3-O-(4'''-O-trans-caffeoyl)-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-galacopyranoside (1), along with luteolin (2), quercetin (3), luteolin-7-O-beta-D-glucoside (4), apigenin-7-O-beta-D-glucoside (5), quercitrin (6), quercetin-3-O-beta-D-arabinoside (7) and 4,5-di-O-caffeoyl quinic acid (8) have been isolated from the leaves of Stevia rebaudiana Bertoni. The structures of these compounds were determined by spectroscopic methods (1H- and 13C-NMR, IR and MS) and by 2D-NMR experiments.

  4. Deep supercooling xylem parenchyma cells of katsura tree (Cercidiphyllum japonicum) contain flavonol glycosides exhibiting high anti-ice nucleation activity.

    PubMed

    Kasuga, Jun; Hashidoko, Yasuyuki; Nishioka, Atsushi; Yoshiba, Megumi; Arakawa, Keita; Fujikawa, Seizo

    2008-09-01

    Xylem parenchyma cells (XPCs) of boreal hardwood species adapt to sub-freezing temperatures by deep supercooling to maintain a liquid state of intracellular water near -40 degrees C. Our previous study found that crude xylem extracts from such tree species exhibited anti-ice nucleation activity to promote supercooling of water. In the present study, thus, we attempted to identify the causative substances of supercooling. Crude xylem extracts from katsura tree (Cercidiphyllum japonicum), of which XPCs exhibited deep supercooling to -40 degrees C, were prepared by methanol extraction. The crude extracts were purified by liquid-liquid extraction and then by silica gel column chromatography. Although all the fractions obtained after each purification step exhibited some levels of anti-ice nucleation activity, only the most active fraction was retained to proceed to the subsequent level of purification. High-performance liquid chromatography (HPLC) analysis of a fraction with the highest level of activity revealed four peaks with high levels of anti-ice nucleation activity in the range of 2.8-9.0 degrees C. Ultraviolet (UV), mass and nuclear magnetic resonance (NMR) spectra revealed that these four peaks corresponded to quercetin-3-O-beta-glucoside (Q3G), kaempferol-7-O-beta-glucoside (K7G), 8-methoxykaempferol-3-O-beta-glucoside (8MK3G) and kaempferol-3-O-beta-glucoside (K3G). Microscopic observations confirmed the presence of flavonoids in cytoplasms of XPCs. These results suggest that diverse kinds of anti-ice nucleation substances, including flavonol glycosides, may have important roles in deep supercooling of XPCs.

  5. Purification of berry flavonol glycosides by long-bed gel permeation chromatography.

    PubMed

    Riihinen, Kaisu R; Gödecke, Tanja; Pauli, Guido F

    2012-06-29

    While Sephadex LH-20 gel is frequently employed as a stationary phase during pre-separations and in open column chromatography systems, its separation power in long-bed gel permeation chromatography (GPC) applications is much less prevalent. Aimed at the characterization of bioactive constituents, a long-bed GPC protocol was established for lingonberry juice concentrate. The method included pre-fractionation over HP-20 resin to eliminate sugars and organic acids as well as a major part of other predominant berry flavonoids (anthocyanins, flavan-3-ols and proanthocyanidins), prior to the elution of the fraction containing 10% (w/w) of quercetin glycosides (QGs). Subsequently, seven major QGs were purified using a 10-m Sephadex LH-20 system and isocratic elution with methanol. The total mass recovery was 99.3±1.4%, after eluting the highly-retained compounds from the employed pre-column with 70% acetone. Injecting 1070 mg per run, the yield of purified QGs ranged from 2 to 6 mg per collected single fraction. The LC-UV/PDA purities of isolated Q-3-O-α-rhamnoside and Q-3-O-β-galactoside were 82 and 94 area% at 250 nm, while the three Q-pentosides showed purities of 59, 30, and 57 area%. By comparison, purity assessment of these isolates by quantitative ¹H NMR (total integral and modified 100% method) led to significantly lower purities of 70 and 52% for Q-rha and Q-gal and 38, 25 and 46% for Q-pentosides, respectively. This can be explained by the presence of hidden residual complexity (RC), which is revealed by the quantitative NMR method. This finding has potentially broader implication as it reveals an unexpected degree of RC in GPC fractions. Despite remarkable separation power for congeneric flavonoids, long-bed GPC on Sephadex LH-20 produces materials, which require careful analysis of purity before interpreting bioassay results.

  6. Interaction of moderate UV-B exposure and temperature on the formation of structurally different flavonol glycosides and hydroxycinnamic acid derivatives in kale (Brassica oleracea var. sabellica).

    PubMed

    Neugart, Susanne; Fiol, Michaela; Schreiner, Monika; Rohn, Sascha; Zrenner, Rita; Kroh, Lothar W; Krumbein, Angelika

    2014-05-07

    Kale has a high number of structurally different flavonol glycosides and hydroxycinnamic acid derivatives. In this study we investigated the interaction of moderate UV-B radiation and temperature on these compounds. Kale plants were grown at daily mean temperatures of 5 or 15 °C and were exposed to five subsequent daily doses (each 0.25 kJ m(-2) d(-1)) of moderate UV-B radiation at 1 d intervals. Of 20 phenolic compounds, 11 were influenced by an interaction of UV-B radiation and temperature, e.g., monoacylated quercetin glycosides. Concomitantly, enhanced mRNA expression of flavonol 3'- hydroxylase showed an interaction of UV-B and temperature, highest at 0.75 kJ m(-2) and 15 °C. Kaempferol glycosides responded diversely and dependent on, e.g., the hydroxycinnamic acid residue. Compounds containing a catechol structure seem to be favored in the response to UV-B. Taken together, subsequent exposure to moderate UV-B radiation is a successful tool for enhancing the flavonoid profile of plants, and temperature should be considered.

  7. Direct analysis of 18 flavonol glycosides, aglycones and terpene trilactones in Ginkgo biloba tablets by matrix solid phase dispersion coupled with ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry.

    PubMed

    Liu, Xin-Guang; Yang, Hua; Cheng, Xiao-Lan; Liu, Lei; Qin, Yong; Wang, Qi; Qi, Lian-Wen; Li, Ping

    2014-08-01

    Analysis and quality control of Ginkgo biloba have been comprehensively studied. However, little attention has been devoted to the simultaneous extraction and analysis of flavonols and terpene trilactones, especially for direct quantification of flavonol glycosides. This work described a rapid strategy for one-step extraction and quantification of the components. A matrix solid phase dispersion (MSPD) method was designed for the extraction of ginkgo ingredients and compared with the heat-reflux and ultrasonic extraction methods. An ultra-high performance liquid chromatography (UHPLC)-tandem-triple-quadrupole-mass spectrometry (QQQ-MS) method was developed for detection of the 18 components, including 10 original flavonol glycosides, 3 aglycones, and 5 lactones. Subsequently, the proposed strategy was used for the analysis of 12 G. biloba tablets. Results showed that MSPD produced comparable extraction efficiency but consumed less time and required lower solvent volumes compared with conventional methods. Without hydrolysis, the concentration detected was much closer to the original in the sample. The total flavonol glycoside contents in ginkgo tablets ranged from 3.59 to 125.21μgmg(-1), and the terpene trilactone varied from 3.45 to 57.8μgmg(-1) among different manufacturers. In conclusion, the proposed MSPD and UHPLC-QQQ-MS is rapid and sensitive in providing comprehensive profile of chemical constituents especially the genuine flavonol glycosides for improved quality control of ginkgo products.

  8. Comparative characterization of total flavonol glycosides and terpene lactones at different ages, from different cultivation sources and genders of Ginkgo biloba leaves.

    PubMed

    Yao, Xin; Shang, Erxin; Zhou, Guisheng; Tang, Yuping; Guo, Sheng; Su, Shulan; Jin, Chun; Qian, Dawei; Qin, Yong; Duan, Jin-Ao

    2012-01-01

    The extract from Ginkgo biloba leaves has become a very popular plant medicine and herbal supplement for its potential benefit in alleviating symptoms associated with peripheral vascular disease, dementia, asthma and tinnitus. Most research on G. biloba leaves focus on the leaves collected in July and August from four to seven year-old trees, however a large number of leaves from fruit cultivars (trees older than 10 years) are ignored and become obsolete after fruit harvest season (November). In this paper, we expand the tree age range (from one to 300 years) and first comparatively analyze the total flavonol glycosides and terpene lactones at different ages, from different cultivation sources and genders of G. biloba leaves collected in November by using the validated HPLC-ELSD and HPLC-PDA methods. The results show that the contents of total terpene lactones and flavonol glycosides in the leaves of young ginkgo trees are higher than those in old trees, and they are higher in male trees than in female trees. Geographical factors appear to have a significant influence on the contents as well. These results will provide a good basis for the comprehensive utilization of G. biloba leaves, especially the leaves from fruit cultivars.

  9. Computer-aided method for identification of major flavone/flavonol glycosides by high-performance liquid chromatography-diode array detection-tandem mass spectrometry (HPLC-DAD-MS/MS).

    PubMed

    Wang, Zhengfang; Lin, Longze; Harnly, James M; Harrington, Peter de B; Chen, Pei

    2014-11-01

    A new computational tool is proposed here for tentatively identifying major (UV quantifiable) flavone/flavonol glycoside peaks of high performance liquid chromatogram (HPLC)-diode array detection (DAD)-tandem mass spectrometry (MS/MS) profiles based on a MATLAB-based script implementing an in-house algorithm. The HPLC-DAD-MS/MS profiles of red onion, Chinese lettuce, carrot leaf, and celery seed extracts were analyzed by the proposed computer-aided screening method for identifying possible flavone/flavonol glycoside peaks from the HPLC-UV and MS total ion current (TIC) chromatograms. The number of identified flavone/flavonol glycoside peaks of the HPLC-UV chromatograms is four, four, six, and nine for red onion, Chinese lettuce, carrot leaf, and celery seed, respectively. These results have been validated by human(s) experts. For the batch processing of nine HPLC-DAD-MS/MS profiles of celery seed extract, the entire script execution time was within 15 s while manual calculation of only one HPLC-DAD-MS/MS profile by a flavonoid expert could take hours. Therefore, this MATLAB-based screening method is able to facilitate the HPLC-DAD-MS/MS analysis of flavone/flavonol glycosides in plants to a large extent.

  10. Flavonol glycosides with lipid accumulation inhibitory activity and simultaneous quantitative analysis of 15 polyphenols and caffeine in the flower buds of Camellia sinensis from different regions by LCMS.

    PubMed

    Morikawa, Toshio; Ninomiya, Kiyofumi; Miyake, Sohachiro; Miki, Yoshinobu; Okamoto, Masaki; Yoshikawa, Masayuki; Muraoka, Osamu

    2013-09-01

    A simultaneous quantitative analytical method for 15 major polyphenols, e.g. five catechins (1-5) and 10 flavonols (6-15), as functional constituents in the extracts of "tea flowers", the flower buds of Camellia sinensis (Theaceae), has been developed. The content of caffeine (16), which showed similar chromatographic behaviour under the analytical conditions, was also determined. To approve the validity of the newly developed protocol, thirteen extracts of the plant's flower buds collected from different regions, i.e. China, Taiwan, Japan and India, were evaluated. The results indicated that the assay was reproducible and precise, and could be readily underutilised for the quality evaluation of tea flowers on the basis of polyphenols' contents. It was noteworthy that the contents of two major constituents, kaempferol 3-O-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (10) and kaempferol 3-O-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→6)-β-D-galactopyranoside (11), varied by region where the flower buds were produced. A new flavonol glycoside, chakaflavonoside B (17), which was isolated in the course of this analytical study, was found to show oleic acid-albumin-induced lipid accumulation inhibitory activity.

  11. Screening of mango (Mangifera indica L.) cultivars for their contents of flavonol O- and xanthone C-glycosides, anthocyanins, and pectin.

    PubMed

    Berardini, Nicolai; Fezer, Ramona; Conrad, Jürgen; Beifuss, Uwe; Carle, Reinhold; Schieber, Andreas

    2005-03-09

    With respect to their browning potential and in consideration of a combined recovery of pectin and phenolic compounds, peels of 14 cultivars and the flesh of nine cultivars of mango (Mangifera indica L.) fruits were analyzed for their contents of flavonol O- and xanthone C-glycosides by high-performance liquid chromatography (HPLC)-diode array detection-electrospray ionization mass spectrometry (ESI-MS). While total amounts of up to 4860 mg/kg dry matter demonstrated the peels to be a rich source of phenolic compounds, only traces could be detected in the flesh. The profile of flavonol glycosides of the peels proved to be highly characteristic and may therefore serve as a tool for authenticity control of mango puree concentrate, which is often produced from unpeeled fruits and represents an important intermediate for the production of mango nectars. Two compounds were isolated by preparative HPLC, and their structures were elucidated on the basis of ESI-MS as well as NMR spectroscopy, establishing the two compounds as rhamnetin 3-O-beta-galactopyranoside and rhamnetin 3-O-beta-glucopyranoside, respectively. In the peels of red-colored cultivars, cyanidin 3-O-galactoside and an anthocyanidin hexoside so far not reported in mango could tentatively be identified. The contents and degrees of esterification of pectins extracted from the lyophilized peels ranged from 12.2 to 21.2% and from 56.3 to 65.6%, respectively, suggesting mango peels also as a promising source of high-quality pectin.

  12. Simultaneous characterisation and quantitation of flavonol glycosides and aglycones in noni leaves using a validated HPLC-UV/MS method.

    PubMed

    Deng, Shixin; West, Brett J; Jensen, C Jarakae

    2008-11-15

    The leaves of Morinda citrifolia L. (noni) have been utilized in a variety of commercial products marketed for their health benefits. This paper reports on a rapid and selective HPLC method for simultaneous characterization and quantitation of four flavonols in an ethanolic extract of noni leaves by using dual detectors of UV (365nm) and ESI-MS (negative mode). The limits of detection and quantitation were between 0.012 and 0.165μg/mL. The intra- and inter-assay precisions, in terms of percent relative standard deviation, are less than 4.38% and 3.50%, respectively. The accuracy, in terms of recovery percentage, ranged from 96.66% to 100.03%. Good linearity (correlation coefficient >0.999) for each calibration curve of standards was achieved in the range investigated. The contents of four flavonoids in the noni leaves varied from 1.16 to 371.6mg/100g dry weight.

  13. Acylated glycosides of hydroxy fatty acid methyl esters generated from the crude resin glycoside (pharbitin) of seeds of Pharbitis nil by treatment with indium(III) chloride in methanol.

    PubMed

    Ono, Masateru; Takigawa, Ayako; Mineno, Tomoko; Yoshimitsu, Hitoshi; Nohara, Toshihiro; Ikeda, Tsuyoshi; Fukuda-Teramachi, Emiko; Noda, Naoki; Miyahara, Kazumoto

    2010-11-29

    Treatment of the crude ether-insoluble resin glycoside (convolvulin) from seeds of Pharbitis nil (Pharbitis Semen), called pharbitin, with indium(III) chloride in methanol provided seven oligoglycosides of hydroxy fatty acid methyl esters partially acylated by 2-methyl-3-hydroxybutyric (nilic) and 2S-methylbutyric acids. Their structures were elucidated on the basis of NMR and MS data and chemical conversions.

  14. Quantitative Analysis and Comparison of Four Major Flavonol Glycosides in the Leaves of Toona sinensis (A. Juss.) Roemer (Chinese Toon) from Various Origins by High-Performance Liquid Chromatography-Diode Array Detector and Hierarchical Clustering Analysis

    PubMed Central

    Sun, Xiaoxiang; Zhang, Liting; Cao, Yaqi; Gu, Qinying; Yang, Huan; Tam, James P.

    2016-01-01

    Background: Toona sinensis (A. Juss.) Roemer is an endemic species of Toona genus native to Asian area. Its dried leaves are applied in the treatment of many diseases; however, few investigations have been reported for the quantitative analysis and comparison of major bioactive flavonol glycosides in the leaves harvested from various origins. Objective: To quantitatively analyze four major flavonol glycosides including rutinoside, quercetin-3-O-β-D-glucoside, quercetin-3-O-α-L-rhamnoside, and kaempferol-3-O-α-L-rhamnoside in the leaves from different production sites and classify them according to the content of these glycosides. Materials and Methods: A high-performance liquid chromatography-diode array detector (HPLC-DAD) method for their simultaneous determination was developed and validated for linearity, precision, accuracy, stability, and repeatability. Moreover, the method established was then employed to explore the difference in the content of these four glycosides in raw materials. Finally, a hierarchical clustering analysis was performed to classify 11 voucher specimens. Results: The separation was performed on a Waters XBridge Shield RP18 column (150 mm × 4.6 mm, 3.5 μm) kept at 35°C, and acetonitrile and H2O containing 0.30% trifluoroacetic acid as mobile phase was driven at 1.0 mL/min during the analysis. Ten microliters of solution were injected and 254 nm was selected to monitor the separation. A strong linear relationship between the peak area and concentration of four analytes was observed. And, the method was also validated to be repeatable, stable, precise, and accurate. Conclusion: An efficient and reliable HPLC-DAD method was established and applied in the assays for the samples from 11 origins successfully. Moreover, the content of those flavonol glycosides varied much among different batches, and the flavonoids could be considered as biomarkers to control the quality of Chinese Toon. SUMMARY Four major flavonol glycosides in the leaves

  15. Characterization of acylated flavonoid-O-glycosides and methoxylated flavonoids from Tagetes maxima by liquid chromatography coupled to electrospray ionization tandem mass spectrometry.

    PubMed

    Parejo, Irene; Jáuregui, Olga; Viladomat, Francesc; Bastida, Jaume; Codina, Carles

    2004-01-01

    Liquid chromatography coupled to negative electrospray ionization (ESI) tandem mass spectrometry (MS/MS) employing a triple quadrupole mass spectrometer was used in the structural determination of acylated flavonoid-O-glycosides and methoxylated flavonoids occurring in Tagetes maxima. The compounds were identified by experiments in full scan mode (MS), and tandem mass experiments (MS/MS) of precursor ion scan, product ion scan, and neutral loss scan modes. In order to characterize the aglycones of the flavonoid glycosides, in-source fragmentation of the deprotonated molecule [M-H]- followed by product ion scan of the resulting aglycone [A-H]- were performed. This combined approach allowed the identification of 51 phenolic compounds, including flavonoid-O-glycosides acylated with galloyl, protocatechuoyl, coumaroyl or caffeoyl groups, methoxylated flavonoids, and hydroxycinnamic acid and phenolic acid derivatives, none of them previously reported in Tagetes maxima.

  16. Separation of four flavonol glycosides from Solanum rostratum Dunal using aqueous two-phase flotation followed by preparative high-performance liquid chromatography.

    PubMed

    Chang, Lin; Shao, Qian; Xi, Xingjun; Chu, Qiao; Wei, Yun

    2017-02-01

    Aqueous two-phase flotation followed by preparative high-performance liquid chromatography was used to separate four flavonol glycosides from Solanum rostratum Dunal. In the aqueous two-phase flotation section, the effects of sublation solvent, solution pH, (NH4 )2 SO4 concentration in aqueous solution, cosolvent, N2 flow rate, flotation time, and volumes of the polyethylene glycol phase on the recovery were investigated in detail, and the optimal conditions were selected: 50 wt% polyethylene glycol 1000 ethanol solvent as the flotation solvent, pH 4, 350 g/L of (NH4 )2 SO4 concentration in aqueous phase, 40 mL/min of N2 flow rate, 30 min of flotation time, 10.0 mL of flotation solvent volume, and two times. After aqueous two-phase flotation concentration, the flotation products were purified by preparative high-performance liquid chromatography. The purities of the final products A and B were 98.1 and 99.0%. Product B was the mixture of three compounds based on the analysis of high-performance liquid chromatography at the temperature of 10°C, while product A was hyperoside after the identification by nuclear magnetic resonance. Astragalin, 3'-O-methylquercetin 3-O-β-d-galactopyranoside, and 3'-O-methylquercetin 3-O-β-d-glucopyranoside were obtained with the purity of 93.8, 97.1, and 99.2%, respectively, after the further separation of product B using preparative high-performance liquid chromatography.

  17. Batatinosides II-VI, acylated lipooligosaccharides from the resin glycosides of sweet potato.

    PubMed

    Escalante-Sánchez, Edgar; Rosas-Ramírez, Daniel; Linares, Edelmira; Bye, Robert; Pereda-Miranda, Rogelio

    2008-10-22

    Sweet potato ( Ipomoea batatas) belongs to the Convolvulaceae (morning glory family) and is native to Mexico and Central America. Its edible tuberous roots have been much appreciated since pre-Hispanic times in Mesoamerica and now play an important role as a basic diet staple and a medicinal plant worldwide. The hexane-soluble extract from roots, through preparative-scale recycling HPLC, yielded five new lipophilic oligosaccharides of jalapinolic acid, batatinosides II-VI ( 1- 5), as well as the known pescapreins I ( 6) and VII ( 7) and murucoidin I ( 8), which are part of the purgative resin glycoside mixture. NMR spectroscopy and FAB mass spectrometry were used to characterize their structures. Compounds 1 and 2 are tetraglycosidic lactones of operculinic acid C. The pentasaccharide structures for compounds 3 and 4 were confirmed to be macrolactones of simonic acid B, and that characterized for 5 was derived from operculinic acid A. The lactonization site of the aglycone was placed at C-3 of the second saccharide unit in all compounds except 4, where it was placed at C-2. All compounds contain an esterifying residue that is composed of a long-chain fatty acid, n-decanoic acid (capric) or n-dodecanoic acid (lauric). In compound 3, an additional short-chain fatty acid, (2 S)-methylbutyric acid, was also identified.

  18. Cucurbitosides F-M, acylated phenolic glycosides from the seeds of Cucurbita pepo.

    PubMed

    Li, Wei; Koike, Kazuo; Tatsuzaki, Masaru; Koide, Atsushi; Nikaido, Tamotsu

    2005-12-01

    Eight new phenolic glycosides, cucurbitosides F-M (1-8), were isolated from the seeds of Cucurbita pepo. Their structures were elucidated as 4-(2-hydroxyethyl)phenyl 5-O-(2-S-2-methylbutyryl)-beta-d-apiofuranosyl(l-->2)-beta-d-glucopyranoside (1), 4-(2-hydroxyethyl)phenyl 5-O-(3-methylbutyryl)-beta-d-apiofuranosyl(l-->2)-beta-d-glucopyranoside (2), 4-(2-hydroxyethyl)phenyl 5-O-nicotinyl-beta-d-apiofuranosyl(l-->2)-beta-d-glucopyranoside (3), 4-(2-hydroxyethyl)phenyl 5-O-(4-aminobenzoyl)-beta-d-apiofuranosyl(l-->2)-beta-d-glucopyranoside (4), 4-(2-hydroxyethyl)-2-methoxyphenyl 5-O-(2-S-2-methylbutyryl)-beta-d-apiofuranosyl(l-->2)-beta-d-glucopyranoside (5), 4-(hydroxymethyl)phenyl 5-O-(2-S-2-methylbutyryl)-beta-d-apiofuranosyl(l-->2)-beta-d-glucopyranoside (6), 4-(hydroxymethyl)phenyl 5-O-nicotinyl-beta-d-apiofuranosyl(l-->2)-beta-d-glucopyranoside (7), and 4-(hydroxymethyl)phenyl 5-O-(4-aminobenzoyl)-beta-d-apiofuranosyl(l-->2)-beta-d-glucopyranoside (8) on the basis of various spectroscopic analyses and analyses of hydrolysis products.

  19. Identification and Structural Characterization of Acylgluconic Acids, Flavonol Glycosides, Limonoids and Alkaloids from the Fruits of Evodia Rutaecarpa by High Performance Liquid Chromatography Coupled to Electrospray Ionization and Quadrupole Time-of-Flight Mass Spectrometry.

    PubMed

    Ling, Yun; Hu, Pei; Zhang, Lifang; Jin, Hongguang; Chen, Jian; Tao, Zhi; Huang, Ling; Ren, Ruoyu

    2016-07-15

    The dried fruit of Evodia rutaecarpa (Juss.) Benth. (ER) is a well-known traditional Chinese medicine and has been used in treatment of headache, abdominal pain, migraine, chill limbs, diarrhea, nausea, hyperbaropathy, dysmenorrheal and postpartum hemorrhage. In this work, a comprehensive characterization of chemical constituents in ER extract is carried out by high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry. The increased power of higher mass resolution and exact mass measurements for precursor and fragment ions lead to detection of 3 acylgluconic acids, 3 flavonol glycosides, 6 limonoids and 24 alkaloids in ER, of which 6 quinolone alkaloids has not been reported previously to our best knowledge. This research enriches our knowledge of chemical constituents of ER and provides a reliable guide for further pharmacology and active mechanism study on this herb.

  20. Biosynthesis of malonylated flavonoid glycosides on the basis of malonyltransferase activity in the petals of Clitoria ternatea.

    PubMed

    Kogawa, Koichiro; Kazuma, Kohei; Kato, Naoki; Noda, Naonobu; Suzuki, Masahiko

    2007-07-01

    The crude malonyltransferase from the petals of Clitoria ternatea was characterized enzymatically to investigate its role on the biosynthetic pathways of anthocyanins and flavonol glycosides. In C. ternatea, a blue flower cultivars (DB) and mauve flower variety (WM) accumulate polyacylated anthocyanins (ternatins) and delphinidin 3-O-(6''-O-malonyl)-beta-glucoside which is one of the precursors of ternatins, respectively. Moreover, WM accumulates minor delphinidin glycosides - 3-O-beta-glucoside, 3-O-(2''-O-alpha-rhamnosyl)-beta-glucoside, 3-O-(2''-O-alpha-rhamnosyl-6''-O-malonyl)-beta-glucoside of delphinidin. These glycosidic patterns for minor anthocyanins in WM are also found among the minor flavonol glycosides in all the varieties including a white flower variety (WW) although the major flavonol glycosides are 3-O-(2''-O-alpha-rhamnosyl)-beta-glucoside, 3-O-(6''-O-alpha-rhamnosyl)-beta-glucoside, 3-O-(2'',6''-di-O-alpha-rhamnosyl)-beta-glucoside of kaempferol, quercetin, and myricetin. How do the enzymatic characteristics affect the variety of glycosidic patterns in the flavonoid glycoside biosynthesis among these varieties? While the enzyme from DB highly preferred delphinidin 3-O-beta-glucoside in the presence of malonyl-CoA, it also has a preference for other anthocyanidin 3-O-beta-glucosides. It could use flavonol 3-O-beta-glucosides in much lower specific activities than anthocyanins; however, it could not utilize 3-O-(2''-O-alpha-rhamnosyl)-beta-glucosides of anthocyanins and flavonols, and 3,3'-di- and 3,3',5'-tri-O-beta-glucoside of delphinidin - other possible precursors in ternatins biosynthesis. It highly preferred malonyl-CoA as an acyl donor in the presence of delphinidin 3-O-beta-glucoside. The crude enzymes prepared from WM and WW had the same enzymatic characteristics. These results suggested that 3-O-(2''-O-alpha-rhamnosyl-6''-O-malonyl)-beta-glucosides of flavonoids were synthesized via 3-O-(6''-O-malonyl)-beta-glucosides rather than via 3-O

  1. Ultra performance liquid chromatography-tandem quadrupole mass spectrometry profiling of anthocyanins and flavonols in cowpea (Vigna unguiculata) of varying genotypes.

    PubMed

    Ojwang, Leonnard O; Dykes, Linda; Awika, Joseph M

    2012-04-11

    The structure of flavonoids in food plants affects bioactivity and important nutritional attributes, like micronutrient bioavailability. This study investigated flavonol and anthocyanin compositions of cowpea (Vigna unguiculata) of varying genotypes. Black, red, green, white, light brown, and golden brown cowpea phenotypes were analyzed for anthocyanins and flavonols using ultra performance liquid chromatography-tandem quadrupole mass spectrometry. Eight anthocyanins and 23 flavonols (15 newly identified in cowpea) were characterized. Mono-, di-, and tri(acyl)glycosides of quercetin were predominant in most phenotypes; myricetin and kaempferol glycosides were present only in specific phenotypes. The red phenotypes had the highest flavonol content (880-1060 μg/g), whereas green and white phenotypes had the lowest (270-350 μg/g). Only black (1676-2094 μg/g) and green (875 μg/g) phenotypes had anthocyanins, predominantly delphinidin and cyanidin 3-O-glucosides. Cowpea phenotype influenced the type and amount of flavonoids accumulated in the seed; this may have implications in selecting varieties for nutrition and health applications.

  2. β-Hydroxydihydrochalcone and flavonoid glycosides along with triterpene saponin and sesquiterpene from the herbs of Pimpinella rhodantha Boiss.

    PubMed

    Özbek, Hilal; Güvenalp, Zühal; Kuruüzüm-Uz, Ay E; Kazaz, Cavit; Demirezer, L Ömür

    2016-01-01

    A new β-hydroxydihydrochalcone glycoside named ziganin (1) and a new acylated flavonol glycoside named isorhamnetin-3-O-α-L-(2″,3″-di-O-trans-coumaroyl)-rhamnopyranoside) (2), along with two known flavonoid glycosides, a β-hydroxydihydrochalcone glycoside, a hydroxybenzoic acid derivative, a trinorguaiane type sesquiterpenoid, a triterpenic saponin and a polyol were isolated from the herbs of Pimpinella rhodantha Boiss. Their structures were elucidated on the basis of spectroscopic analyses including 1D-and 2D-NMR, UV, IR, CD, ESI-MS, APCI-MS, HR-ESI-MS techniques. The isolated compounds were evaluated for their antioxidant capacity through the DPPH free-radical scavenging assay and ferrous ion-chelating power test.

  3. Fluorescence imaging of soybean flavonol isolines

    NASA Astrophysics Data System (ADS)

    Kim, Moon S.; Lee, Edward H.; Mulchi, Charles L.; McMurtrey, James E., III; Chappelle, Emmett W.; Rowland, Randy A.

    1998-07-01

    Experiments were conducted to characterize the fluorescence emission of leaves from four soybean ('Harosoy') plants containing different concentrations of flavonols (kaempferol glycosides). The investigation utilized genetically mutated soybean flavonol isolines grown in a constant environment, thus limiting factors known to affect fluorescence emission characteristics other than different kaempferol glycosides concentrations. Flavonol isolines included OX922, OX941, OX942, OX944. The first two isolines contain kaempferol (K) glycosides; K3, K6, and K9, and the latter two did not have K3, K6, and K9. A fluorescence imaging system (FIS) was used to characterize steady state florescence images of the sample leaves measured at wavelengths centered at 450, 550, 680, and 740 nm with an excitation at 360 nm. Images taken with FIS greatly complement non-imaging fluorescence measurements by characterizing the spatial variation of fluorescence within leaves. We also acquired fluorescence emission spectra to characterize spectral features of the soybean flavonol isolines. The emission spectral shape of the fluorescence emission characteristics were not significantly different between the soybeans that contain kaempferol glycosides and the ones that do not contain kaempferol glycosides. Typical emission maxima of green vegetation in the blue, green, red, and far-red bands were noticed in all four soybean isolines. However, plants containing kaempferol glycosides, OX922 and OX941 had significantly lower intensities throughout the wavelength regions. These results imply that fluorescence emission intensities in the fluorescence emission bands studied are significantly affected by the presence and absence of kaempferol glycosides concentrations (UV radiation screening compounds). Pure kaempferol glycoside dissolved in solution show minimal fluorescence emission when excited with the absorption maximum radiation at 365 nm. However, a broad band emission can be seen in the green

  4. Characterization of flavonols in cranberry (Vaccinium macrocarpon) powder.

    PubMed

    Vvedenskaya, Irina O; Rosen, Robert T; Guido, Jane E; Russell, David J; Mills, Kent A; Vorsa, Nicholi

    2004-01-28

    Flavonoids were extracted from cranberry powder with acetone and ethyl acetate and subsequently fractionated with Sephadex LH-20 column chromatography. The fraction eluted with a 60% methanol solution was composed primarily of phenolic constituents with maximum absorbance at 340 nm. A high-performance liquid chromatography procedure was developed, which resolved 22 distinct peaks with UV/vis and mass spectra corresponding to flavonol glycoside conjugates. Six new constituents not previously reported in cranberry or in cranberry products were determined through NMR spectroscopy to be myricetin-3-beta-xylopyranoside, quercetin-3-beta-glucoside, quercetin-3-alpha-arabinopyranoside, 3'-methoxyquercetin-3-alpha-xylopyranoside, quercetin-3-O-(6' '-p-coumaroyl)-beta-galactoside, and quercetin-3-O-(6' '-benzoyl)-beta-galactoside. Quercetin-3-O-(6' '-p-coumaroyl)-beta-galactoside and quercetin-3-O-(6' '-benzoyl)-beta-galactoside represent a new class of cranberry flavonol compounds with three conjugated components consisting of a flavonol, sugar, and carboxylic acid (benzoic or hydroxycinnamic acids). This is also the first report identifying quercetin-3-arabinoside in both furanose and pyranose forms in cranberry. Elucidation of specific flavonol glycosides in cranberry is significant since the specificity of the sugar moiety may play a role in the bioavailability of the flavonol glycosides in vivo.

  5. 7-Rhamnosylated Flavonols Modulate Homeostasis of the Plant Hormone Auxin and Affect Plant Development*

    PubMed Central

    Kuhn, Benjamin M.; Errafi, Sanae; Bucher, Rahel; Dobrev, Petre; Geisler, Markus; Bigler, Laurent; Zažímalová, Eva; Ringli, Christoph

    2016-01-01

    Flavonols are a group of secondary metabolites that affect diverse cellular processes. They are considered putative negative regulators of the transport of the phytohormone auxin, by which they influence auxin distribution and concomitantly take part in the control of plant organ development. Flavonols are accumulating in a large number of glycosidic forms. Whether these have distinct functions and diverse cellular targets is not well understood. The rol1-2 mutant of Arabidopsis thaliana is characterized by a modified flavonol glycosylation profile that is inducing changes in auxin transport and growth defects in shoot tissues. To determine whether specific flavonol glycosides are responsible for these phenotypes, a suppressor screen was performed on the rol1-2 mutant, resulting in the identification of an allelic series of UGT89C1, a gene encoding a flavonol 7-O-rhamnosyltransferase. A detailed analysis revealed that interfering with flavonol rhamnosylation increases the concentration of auxin precursors and auxin metabolites, whereas auxin transport is not affected. This finding provides an additional level of complexity to the possible ways by which flavonols influence auxin distribution and suggests that flavonol glycosides play an important role in regulating plant development. PMID:26742840

  6. 7-Rhamnosylated Flavonols Modulate Homeostasis of the Plant Hormone Auxin and Affect Plant Development.

    PubMed

    Kuhn, Benjamin M; Errafi, Sanae; Bucher, Rahel; Dobrev, Petre; Geisler, Markus; Bigler, Laurent; Zažímalová, Eva; Ringli, Christoph

    2016-03-04

    Flavonols are a group of secondary metabolites that affect diverse cellular processes. They are considered putative negative regulators of the transport of the phytohormone auxin, by which they influence auxin distribution and concomitantly take part in the control of plant organ development. Flavonols are accumulating in a large number of glycosidic forms. Whether these have distinct functions and diverse cellular targets is not well understood. The rol1-2 mutant of Arabidopsis thaliana is characterized by a modified flavonol glycosylation profile that is inducing changes in auxin transport and growth defects in shoot tissues. To determine whether specific flavonol glycosides are responsible for these phenotypes, a suppressor screen was performed on the rol1-2 mutant, resulting in the identification of an allelic series of UGT89C1, a gene encoding a flavonol 7-O-rhamnosyltransferase. A detailed analysis revealed that interfering with flavonol rhamnosylation increases the concentration of auxin precursors and auxin metabolites, whereas auxin transport is not affected. This finding provides an additional level of complexity to the possible ways by which flavonols influence auxin distribution and suggests that flavonol glycosides play an important role in regulating plant development.

  7. [Biologically active substances of plant origin. Flavonols and flavones: prevalence, dietary sourses and consumption].

    PubMed

    Tutel'ian, V A; Lashneva, N V

    2013-01-01

    Flavonoids are the most numerous group of natural polyphenolic compounds, the secondary metabolites of plants that may play an important role in human health protection. Flavonols and flavones constitute the main two classes of flavonoids, whose antioxidant properties and high biological activity have been proofed both in vitro and in vivo. This review summarizes data, concerning the structure, occurrence and content of the main flavonols (quercetin, kaempherol, myricetin, isorhamnetin) and flavones (apigenin, luteolin) in some most widely consumed foodstuffs, including vegetables, fruits, berries, nuts, beverages and other products of plant origin. The products with high content of these biologically active food compounds--the major dietary sources of them--are noted. Forms of flavonols and flavones more often distributed among edible plants are characterized and some of their known glycosides occurred in foods are enumerated. Some peculiarities, characteristic to flavonol sand flavones glycosilation (O- and/or C-glycosides formation) are described. The data for flavonol and flavone glycosides composition (profiles) of some commonly consumed commodities rich by these flavonoids (onions, cabbage, apples at al.) are shown. Information about levels of daily dietary intake of total and individual flavonols and flavones in several countries is presented. The questions about dietary habits and lifestyle factors and the contribution of certain foods to flavonols and flavones in daily dietary consumption values are also discussed.

  8. Genetic Variation of Flavonols Quercetin, Myricetin, and Kaempferol in the Sri Lankan Tea (Camellia sinensis L.) and Their Health-Promoting Aspects

    PubMed Central

    Jeganathan, Brasathe; Kottawa-Arachchi, J. Dananjaya; Ranatunga, Mahasen A. B.; Abeysinghe, I. Sarath B.; Gunasekare, M. T. Kumudini; Bandara, B. M. Ratnayake

    2016-01-01

    Flavonol glycosides in tea leaves have been quantified as aglycones, quercetin, myricetin, and kaempferol. Occurrence of the said compounds was reported in fruits and vegetable for a long time in association with the antioxidant potential. However, data on flavonols in tea were scanty and, hence, this study aims to envisage the flavonol content in a representative pool of accessions present in the Sri Lankan tea germplasm. Significant amounts of myricetin, quercetin, and kaempferol have been detected in the beverage type tea accessions of the Sri Lankan tea germplasm. This study also revealed that tea is a good source of flavonol glycosides. The Camellia sinensis var. sinensis showed higher content of myricetin, quercetin, and total flavonols than var. assamica and ssp. lasiocalyx. Therefore flavonols and their glycosides can potentially be used in chemotaxonomic studies of tea germplasm. The nonbeverage type cultivars, especially Camellia rosaflora and Camellia japonica Red along with the exotic accessions resembling China type, could be useful in future germplasm studies because they are rich sources of flavonols, namely, quercetin and kaempferol, which are potent antioxidants. The flavonol profiles can be effectively used in choosing parents in tea breeding programmes to generate progenies with a wide range of flavonol glycosides. PMID:27366737

  9. Acylated Glycosidic Acid Methyl Esters Generated from the Convolvulin Fraction of Rhizoma Jalapae Braziliensis by Treatment with Indium(III) Chloride in Methanol.

    PubMed

    Ono, Masateru; Oda, Satoko; Yasuda, Shin; Mineno, Tomoko; Okawa, Masafumi; Kinjo, Junei; Miyashita, Hiroyuki; Yoshimitsu, Hitoshi; Nohara, Toshihiro; Miyahara, Kazumoto

    2017-01-01

    Four hexaglycosides of methyl 3S,12S-dihydroxyhexadecanoate (1-4) were provided after treatment of the crude convolvulin fraction from Rhizoma Jalapae Braziliensis (the root of Ipomoea operculata (GOMES) MART., Convolvulaceae) with indium(III) chloride in methanol. The structures of 1-4 were elucidated on the basis of spectroscopic and chemical methods. Their sugar moieties were partially acylated with organic acids including (3S,9R)-3,6:6,9-diepoxydecanoic (exogonic) acid, (E)-2-methylbut-2-enoic (tiglic) acid, and isovaleric acid.

  10. Characterization and content of flavonol derivatives of Allium ursinum L. plant.

    PubMed

    Oszmiański, J; Kolniak-Ostek, J; Wojdyło, A

    2013-01-09

    The phenolic compounds were extracted from green and yellow leaves, stalks, and seeds of garlic ( Allium ursinum L.). The extracts were analyzed by liquid chromatography-photodiode array detector-electrospray ionization-tandem mass spectrometry (LC-PDA-ESI-MS/MS). In total, 21 compounds were detected. The flavonol derivatives were identified on the basis of their ultraviolet (UV) spectra and fragmentation patterns in collision-induced dissociation experiments. On the basis of accurate MS and MS/MS data, six compounds were newly identified in bear's garlic, mainly the kaempferol derivatives. As far as the investigated parts of garlic are concerned, the kaempferol derivatives were found to be predominant in yellow leaves [2362.96 mg/100 g of dry matter (dm)], followed by green leaves (1856.31 mg/100 g of dm). Seeds contained the minimal phenolic compounds, less than stalks. The yellow leaves of A. ursinum possessed a much larger content of compounds acylated with p-coumaric acid than green leaves (1299.97 versus 855.67 mg/100 g of dm, respectively). The stalks and seeds contained much more non-acetylated than acetylated flavonoid glycosides with p-coumaric acid compounds (162.4 versus 62.82 mg/100 g of dm and 105.49 versus 24.18 mg/100 g of dm, respectively).

  11. Five new resin glycoside derivatives isolated from the convolvulin fraction of seeds of Quamoclit pennata after treatment with indium(III) chloride in methanol.

    PubMed

    Akiyama, Kousuke; Yamamoto, Kazutaka; Mineno, Tomoko; Okawa, Masafumi; Kinjo, Junei; Yoshimitsu, Hitoshi; Nohara, Toshihiro; Ono, Masateru

    2014-01-01

    Three new acylated methyl glycosides and two new acylated glycosidic acid methyl esters were isolated after treatment of the crude ether-insoluble resin glycoside (convolvulin) fraction from seeds of Quamoclit pennata BOJER (Convolvulaceae) with indium(III) chloride in methanol. Their structures were elucidated on the basis of spectroscopic data and chemical conversions.

  12. Phytosteryl glycosides reduce cholesterol absorption: mechanisms in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytosteryl glycosides occur in natural foods but little is known about their metabolism and bioactivity. Purified acylated steryl glycosides (ASG) were compared with phytosteryl esters (PSE) in mice. Animals on a phytosterol-free diet received ASG or PSE by gavage in purified soybean oil along with...

  13. A new C-methylated flavonoid glycoside from Pinus densiflora.

    PubMed

    Jung, M J; Choi, J H; Chung, H Y; Jung, J H; Choi, J S

    2001-12-01

    A new C-methyl flavonol glycoside, 5,7,8,4'-tetrahydroxy-3-methoxy-6-methylflavone 8-O-beta-D-glucopyranoside (1), has been isolated from the needles of Pinus densiflora, together with kaempferol 3-O-beta-(6"-acetyl)-galactopyranoside.

  14. Flavonol Glycosides from Euphorbia microsciadia Bioss. with their Immunomodulatory Activities

    PubMed Central

    Ghanadian, Syed Mustafa; Ayatollahi, Abdul Majid; Afsharypour, Suleiman; Hareem, Sumaira; Abdalla, Omer Mohamed; Jules Kezetas Bankeu, Jean

    2012-01-01

    Four known flavonoids: quercetin 3-O-β-D-rutinoside (Q3Rut), myricetin 3-O-β-D-galactopyranoside (M3Gal), quercetin 3-O-β-D-galactopyranoside (Q3Gal) and quercetin 3-O-β-D-glucopyranoside (Q3Glc), for the first time were isolated from aerial parts of Euphorbia microsciadia. The chemical structure of them was elucidated on the basis of 1 and 2 D-NMR spectra and different spectroscopic techniques. The immunomodulatory activities of isolated compounds were compared using standard T-cell proliferation assay. These data showed that lymphocyte suppression activity of flavonoids (1-4) were comparatively lower than prednisolon as a standard drug. Immunosuppressive activity of flavonoids with hydroxyl groups at both 3′-and 4′-positions in their B-ring (Q3Gal) were more than those with 3′-,4′-and 5′-hydroxyl substitution (M3Gal). In these compounds, Q3Gal showed the most inhibitory activity, whereas M3Gal showed the least lymphocyte antiprolifeartive activity. PMID:24250520

  15. Kaempferol glycosides in the flowers of carnation and their contribution to the creamy white flower color.

    PubMed

    Iwashina, Tsukasa; Yamaguchi, Masa-atsu; Nakayama, Masayoshi; Onozaki, Takashi; Yoshida, Hiroyuki; Kawanobu, Shuji; Onoe, Hiroshi; Okamura, Masachika

    2010-12-01

    Three flavonol glycosides were isolated from the flowers of carnation cultivars 'White Wink' and 'Honey Moon'. They were identified from their UV, MS, 1H and 13C NMR spectra as kaempferol 3-O-neohesperidoside, kaempferol 3-O-sophoroside and kaempferol 3-O-glucosyl-(1 --> 2)-[rhamnosyl-(1 --> 6)-glucoside]. Referring to previous reports, flavonols occurring in carnation flowers are characterized as kaempferol 3-O-glucosides with additional sugars binding at the 2 and/or 6-positions of the glucose. The kaempferol glycoside contents of a nearly pure white flower and some creamy white flower lines were compared. Although the major glycoside was different in each line, the total kaempferol contents of the creamy white lines were from 5.9 to 20.9 times higher than the pure white line. Thus, in carnations, kaempferol glycosides surely contribute to the creamy tone of white flowers.

  16. New benzophenone and quercetin galloyl glycosides from Psidium guajava L.

    PubMed Central

    Matsuzaki, Keiichi; Ishii, Rie; Kobiyama, Kaori

    2010-01-01

    New benzophenone and flavonol galloyl glycosides were isolated from an 80% MeOH extract of Psidium guajava L. (Myrtaceae) together with five known quercetin glycosides. The structures of the novel glycosides were elucidated to be 2,4,6-trihydroxybenzophenone 4-O-(6″-O-galloyl)-β-d-glucopyranoside (1, guavinoside A), 2,4,6-trihydroxy-3,5-dimethylbenzophenone 4-O-(6″-O-galloyl)-β-d-glucopyranoside (2, guavinoside B), and quercetin 3-O-(5″-O-galloyl)-α-l-arabinofuranoside (3, guavinoside C) by NMR, MS, UV, and IR spectroscopies. Isolated phenolic glycosides showed significant inhibitory activities against histamine release from rat peritoneal mast cells, and nitric oxide production from a murine macrophage-like cell line, RAW 264.7. PMID:20354804

  17. Acylated and non-acylated flavonol monoglycosides from the Indian minor spice Nagkesar (Mammea longifolia).

    PubMed

    Jagan Mohan Rao, Lingamallu; Yada, Hiroshi; Ono, Hiroshi; Yoshida, Mitsuru

    2002-05-22

    A methanol extract of nagkesar (buds of Mammea longifolia), which showed strong radical scavenging activity, yielded 13 compounds by separations using column chromatography and HPLC. Structure elucidation of these compounds was achieved by (1)H and (13)C NMR, including DQF-COSY, TOCSY, DEPT, HMQC, HSQC, and HMBC. They include two new compounds, quercetin 3-O-(2' ',4' 'di-E-p-coumaroyl)-alpha-L-rhamno-pyranoside and quercetin 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, along with known compounds kaempferol, quercetin, the isopropylidenedioxy derivative of shikimic acid, kaempferol 3-O-(2' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-alpha-L-rhamnopyranoside, shikimic acid, kaempferol 3-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-glucopyranoside, and beta-sitosterol 3-O-beta-D-glucopyranoside.

  18. A novel cytotoxic flavonoid glycoside from Physalis angulata.

    PubMed

    Ismail, N; Alam, M

    2001-08-01

    A new flavonol glycoside, myricetin 3-O-neohesperidoside (1) was isolated from a cytotoxic MeOH extract of the leaves of Physalis angulata. Compound 1 showed remarkable cytotoxicity in vitro against murine leukemia cell line P-388, epidermoid carcinoma of the nasopharynx KB-16 cells, and lung adenocarcinoma A-549 with ED(50) values of 0.048, 0.50 and 0.55 microg ml(-1), respectively.

  19. Biochemical and Molecular Characterization of a Flavonoid 3-O-glycosyltransferase Responsible for Anthocyanins and Flavonols Biosynthesis in Freesia hybrida

    PubMed Central

    Sun, Wei; Liang, Lingjie; Meng, Xiangyu; Li, Yueqing; Gao, Fengzhan; Liu, Xingxue; Wang, Shucai; Gao, Xiang; Wang, Li

    2016-01-01

    The glycosylation of flavonoids increases their solubility and stability in plants. Flowers accumulate anthocyanidin and flavonol glycosides which are synthesized by UDP-sugar flavonoid glycosyltransferases (UFGTs). In our previous study, a cDNA clone (Fh3GT1) encoding UFGT was isolated from Freesia hybrida, which was preliminarily proved to be invovled in cyanidin 3-O-glucoside biosynthesis. Here, a variety of anthocyanin and flavonol glycosides were detected in flowers and other tissues of F. hybrida, implying the versatile roles of Fh3GT1 in flavonoids biosynthesis. To further unravel its multi-functional roles, integrative analysis between gene expression and metabolites was investigated. The results showed expression of Fh3GT1 was positively related to the accumulation of anthocyanins and flavonol glycosides, suggesting its potential roles in the biosynthesis of both flavonoid glycosides. Subsequently, biochemical analysis results revealed that a broad range of flavonoid substrates including flavonoid not naturally occurred in F. hybrida could be recognized by the recombinant Fh3GT1. Both UDP-glucose and UDP-galactose could be used as sugar donors by recombinant Fh3GT1, although UDP-galactose was transferred with relatively low activity. Furthermore, regiospecificity analysis demonstrated that Fh3GT1 was able to glycosylate delphinidin at the 3-, 4-′, and 7- positions in a sugar-dependent manner. And the introduction of Fh3GT1 into Arabidopsis UGT78D2 mutant successfully restored the anthocyanins and flavonols phenotypes caused by lost-of-function of the 3GT, indicating that Fh3GT1 functions as a flavonoid 3-O-glucosyltransferase in vivo. In summary, these results demonstrate that Fh3GT1 is a flavonoid 3-O-glycosyltransferase using UDP-glucose as the preferred sugar donor and may involve in flavonoid glycosylation in F. hybrida. PMID:27064818

  20. Flavonols: old compounds for old roles

    PubMed Central

    Pollastri, Susanna; Tattini, Massimiliano

    2011-01-01

    Background New roles for flavonoids, as developmental regulators and/or signalling molecules, have recently been proposed in eukaryotic cells exposed to a wide range of environmental stimuli. In plants, these functions are actually restricted to flavonols, the ancient and widespread class of flavonoids. In mosses and liverworts, the whole set of genes for flavonol biosynthesis – CHS, CHI, F3H, FLS and F3′H – has been detected. The flavonol branch pathway has remained intact for millions of years, and is almost exclusively involved in the responses of plants to a wide array of stressful agents, despite the fact that evolution of flavonoid metabolism has produced >10 000 structures. Scope Here the emerging functional roles of flavonoids in the responses of present-day plants to different stresses are discussed based on early, authoritative views of their primary functions during the colonization of land by plants. Flavonols are not as efficient as other secondary metabolites in absorbing wavelengths in the 290–320 nm spectral region, but display the greatest potential to keep stress-induced changes in cellular reactive oxygen species homeostasis under control, and to regulate the development of individual organs and the whole plant. Very low flavonol concentrations, as probably occurred in early terrestrial plants, may fully accomplish these regulatory functions. Conclusions During the last two decades the routine use of genomic, chromatography/mass spectrometry and fluorescence microimaging techniques has provided new insights into the regulation of flavonol metabolism as well as on the inter- and intracellular distribution of stress-responsive flavonols. These findings offer new evidence on how flavonols may have performed a wide array of functional roles during the colonization of land by plants. In our opinion this ancient flavonoid class is still playing the same old and robust roles in present-day plants. PMID:21880658

  1. Flavonol galactoside caffeiate ester and homoisoflavones from Caesalpinia millettii HOOK. et ARN.

    PubMed

    Chen, Ping; Yang, Jun-Shan

    2007-04-01

    Chemical examination of the stems of Caesalpinia millettii HOOK. et ARN. led to the isolation of new flavonol glycoside caffeiate ester (1) and homoisoflavone (2), along with four known homoisoflavones: eucomin (3), bonducellin (4), 8-methoxybonducellin (5) and intricatinol (6). The structures of 1 and 2 were established to be tamarixetin 3-O-(6''-O-E-caffeoyl)-beta-D-galactopyranoside (1) and (Z)-7-hydroxy-8-methoxy-3-(4-methoxybenzyl) chroman-4-one (2) on the basis of detailed analyses of physical, chemical, and spectral data. Compounds 3-6 were isolated from this plant for the first time.

  2. [Hypoglycemic and hypolipidemic effects of quercetin and its glycosides].

    PubMed

    Yan, Shu-xia; Li, Xian; Sun, Chong-de; Chen, Kun-song

    2015-12-01

    Quercetin and its glycosides are important flavonols in traditional herbal drugs and plant-derived food, and they have diverse hiological activities such as antioxidant, anticarcinogenic, anti-inflammatory, hypoglycemic and hypolipidemic activities. Numerous studies have demonstrated that quercetin and its glycosides were effective in the prevention and treatment of non-infectious chronic disease such as diabetes, obesity, and hyperlipidemia. They can regulate glucose and lipid metaholism through different mechanisms. They can decrease blood glucose via protecting pancreatic/p cells or/and improving insulin sensitivity. Also, they have lipid-lowering effects, which may be the result of regulation of lipid catabolism or/and anabolism. Their distributions, as well as the hypoglycemic and hypolipidemic effects are reviewed in this paper. In addition, further bioactivities as well as their dose-activity relationship, structure-activity relationship, bioavailability, and future clinical application of quercetin and its glycosides are discussed and proposed.

  3. High-flavonol tomatoes resulting from the heterologous expression of the maize transcription factor genes LC and C1.

    PubMed

    Bovy, Arnaud; de Vos, Ric; Kemper, Mark; Schijlen, Elio; Almenar Pertejo, Maria; Muir, Shelagh; Collins, Geoff; Robinson, Sue; Verhoeyen, Martine; Hughes, Steve; Santos-Buelga, Celestino; van Tunen, Arjen

    2002-10-01

    Flavonoids are a group of polyphenolic plant secondary metabolites important for plant biology and human nutrition. In particular flavonols are potent antioxidants, and their dietary intake is correlated with a reduced risk of cardiovascular diseases. Tomato fruit contain only in their peel small amounts of flavonoids, mainly naringenin chalcone and the flavonol rutin, a quercetin glycoside. To increase flavonoid levels in tomato, we expressed the maize transcription factor genes LC and C1 in the fruit of genetically modified tomato plants. Expression of both genes was required and sufficient to upregulate the flavonoid pathway in tomato fruit flesh, a tissue that normally does not produce any flavonoids. These fruit accumulated high levels of the flavonol kaempferol and, to a lesser extent, the flavanone naringenin in their flesh. All flavonoids detected were present as glycosides. Anthocyanins, previously reported to accumulate upon LC expression in several plant species, were present in LC/C1 tomato leaves but could not be detected in ripe LC/C1 fruit. RNA expression analysis of ripening fruit revealed that, with the exception of chalcone isomerase, all of the structural genes required for the production of kaempferol-type flavonols and pelargonidin-type anthocyanins were induced strongly by the LC/C1 transcription factors. Expression of the genes encoding flavanone-3'-hydroxylase and flavanone-3'5'-hydroxylase, which are required for the modification of B-ring hydroxylation patterns, was not affected by LC/C1. Comparison of flavonoid profiles and gene expression data between tomato leaves and fruit indicates that the absence of anthocyanins in LC/C1 fruit is attributable primarily to an insufficient expression of the gene encoding flavanone-3'5'-hydroxylase, in combination with a strong preference of the tomato dihydroflavonol reductase enzyme to use the flavanone-3'5'-hydroxylase reaction product dihydromyricetin as a substrate.

  4. A new isorhamnetin glycoside and other phenolic compounds from Callianthemum taipaicum.

    PubMed

    Wang, Dong-Mei; Pu, Wen-Jun; Wang, Yong-Hong; Zhang, Yu-Juan; Wang, Shan-Shan

    2012-04-17

    A new flavonol glycoside together with five known phenolic compounds were isolated from the whole herb of Callianthemum taipaicum. The compounds were identified as isorhamnetin-3-O-α-L-arabinoside-7-O-β-D-glucoside (1), isorhamnetin-3-O-β-D-glucoside (2), dibutyl phthalate (3), (+)-1-hydroxylpinoresinol-4'-β-D-glucoside (4), pinoresinol-4'-O-β-D-glucoside (5) and 2-phenylethyl-β-primeveroside (6). Compound 1 was identified as a new flavonol glycoside. The compound 6 was isolated for the first time as natural product. All compounds were isolated for the first time from the Callianthemum genus. Furthermore, the 2D-NMR data of the four known compounds 2-5 are given for the first time in this paper. All the structures were identified on the basis of detailed spectral analysis. The compounds 1 and 4 exhibited certain antifungal activity.

  5. Iridoid glycosides isolated from Scrophularia dentata Royle ex Benth. and their anti-inflammatory activity.

    PubMed

    Zhang, Liuqiang; Zhu, Tiantian; Qian, Fei; Xu, Jinwen; Dorje, Gaawe; Zhao, Zhili; Guo, Fujiang; Li, Yiming

    2014-10-01

    Scrodentosides A-E (1-5), five new acylated iridoid glycosides, together with 19 known ones, were isolated from the whole plant of Scrophularia dentata Royle ex Benth. The structures of these isolated glycosides were elucidated by spectroscopic methods. Bioassay showed that compounds 7 and 11 had significant inhibitory effect against NF-κB activation with IC50 value of 43.7 μM and 1.02 μM respectively.

  6. Antitrypanosomal activity of some pregnane glycosides isolated from Caralluma species.

    PubMed

    Abdel-Sattar, Essam; Shehab, Naglaa G; Ichino, Chikara; Kiyohara, Hiroaki; Ishiyama, Aki; Otoguro, Kazuhiko; Omura, Satoshi; Yamada, Haruki

    2009-06-01

    Pregnane glycosides previously isolated from genus Caralluma (C. Penicillata, C. tuberculata and C. russelliana) were tested for their antitrypanosomal activity. Penicilloside E showed the highest antitrypanosomal activity (IC(50) 1.01 microg/ml) followed by caratuberside C (IC(50) 1.85 microg/ml), which exhibited the highest selectivity index (SI 12.04). It was noticed that acylation is required for the antitrypanosomal activity while glycosylation at C-20 has no significant effect on the activity.

  7. Oxidative acylation using thioacids

    NASA Technical Reports Server (NTRS)

    Liu, R.; Orgel, L. E.

    1997-01-01

    Several important prebiotic reactions, including the coupling of amino acids into polypeptides by the formation of amide linkages, involve acylation. Theae reactions present a challenge to the understanding of prebiotic synthesis. Condensation reactions relying on dehydrating agents are either inefficient in aqueous solution or require strongly acidic conditions and high temperatures. Activated amino acids such as thioester derivatives have therefore been suggested as likely substrates for prebiotic peptide synthesis. Here we propose a closely related route to amide bond formation involving oxidative acylation by thioacids. We find that phenylalanine, leucine and phenylphosphate are acylated efficiently in aqueous solution by thioacetic acid and an oxidizing agent. From a prebiotic point of view, oxidative acylation has the advantage of proceeding efficiently in solution and under mild conditions. We anticipate that oxidative acylation should prove to be a general method for activating carboxylic acids, including amino acids.

  8. Characterization of Brassica napus Flavonol Synthase Involved in Flavonol Biosynthesis in Brassica napus L.

    PubMed

    Vu, Tien Thanh; Jeong, Chan Young; Nguyen, Hoai Nguyen; Lee, Dongho; Lee, Sang A; Kim, Ji Hye; Hong, Suk-Whan; Lee, Hojoung

    2015-09-09

    Recently, Brassica napus has become a very important crop for plant oil production. Flavonols, an uncolored flavonoid subclass, have a high antioxidative effect and are known to have antiproliferative, antiangiogenic, and neuropharmacological properties. In B. napus, some flavonoid structural genes have been identified, such as, BnF3H-1, BnCHS, and BnC4H-1. However, no studies on FLS genes in B. napus have been conducted. Thus, in this study, we cloned and characterized the function of BnFLS gene B. napus. By overexpression of the BnFLS gene, flavonol (kaempferol and quercetin) levels were recovered in the Arabidopsis atfls1-ko mutant. In addition, we found that the higher endogenous flavonol levels of BnFLS-ox in vitro shoots correlated with slightly higher ROS scavenging activities. Thus, our results indicate that the BnFLS gene encodes for a BnFLS enzyme that can be manipulated to specifically increase flavonol accumulation in oilseed plants and other species such as Arabidopsis.

  9. Cardiac glycoside overdose

    MedlinePlus

    ... found in the leaves of the digitalis (foxglove) plant. This plant is the original source of this medicine. People ... Digitoxin (Crystodigin) Digoxin (Lanoxicaps, Lanoxin) Besides the foxglove plant, cardiac glycosides also occur naturally in plants such ...

  10. Iridoid glycosides from Globularia trichosantha.

    PubMed

    Caliş, I; Kirmizibekmez, H; Sticher, O

    2001-01-01

    A new iridoid glycoside, deacetylalpinoside (2), was isolated from the aerial parts of Globularia trichosantha together with nine known iridoid glycosides: catalpol, 10-O-benzoyl-catalpol, aucubin, asperuloside, deacetylasperuloside, asperulosidic acid, scandoside, geniposidic acid, and alpinoside (1). From the underground parts of the same plant, two new bisiridoid glycosides, globulosides A (3) and B (4); a known iridoid glycoside, globularidin; a lignan glycoside, liriodendrin; and seven phenylethanoid glycosides, arenarioside, verbascoside (= acteoside), isoacteoside, crenatoside, isocrenatoside, and trichosanthosides A and B, were isolated. Compounds 2-4 are new iridoids containing an 8,9 double bond representing a rare carbon skeleton. Their structures were established by spectroscopic methods.

  11. Varietal differences in the flavonol content of mulberry (Morus spp.) leaves and genetic analysis of quercetin 3-(6-malonylglucoside) for component breeding.

    PubMed

    Sugiyama, Mari; Katsube, Takuya; Koyama, Akio; Itamura, Hiroyuki

    2013-09-25

    The varietal differences in the flavonol glycosides rutin, isoquercitrin, kaempferol 3-(6-rhamnosylglucoside), quercetin 3-(6-malonylglucoside), astragalin, quercetin 3-(6-acetylglucoside), and kaempferol 3-(6-malonylglucoside) contained in mulberry leaves were elucidated. This information was used for breeding mulberry cultivars with a high concentration of functional components. The flavonol content, composition, and proportion in leaves varied widely. 'Kobuchizawa 1' had the highest level of total flavonols (1819 mg/100 g of dry weight), 5 times higher than that of 'Mikurasima 15' (393 mg/100 g of dry weight). Quercetin 3-(6-malonylglucoside) was the most abundant flavonol, although it was not found in all cultivars. Quercetin 3-(6-acetylglucoside) was only found in 'Keguwa'. From the quercetin 3-(6-malonylglucoside) content in crossbred offspring, malonyltransferase, an enzyme involved in quercetin 3-(6-malonylglucoside) synthesis, was acquired according to Mendelian inheritance. An offspring with a higher quercetin 3-(6-malonylglucoside) level than both parents was obtained from the crossing. This suggested that crossbreeding was effective for acquiring cultivars with a higher content of quercetin 3-(6-malonylglucoside).

  12. Steviol glycoside biosynthesis.

    PubMed

    Brandle, J E; Telmer, P G

    2007-07-01

    Steviol glycosides are found in high concentrations in the leaves of the Paraguayan perennial herb Stevia rebaudiana and their intense sweetness, as well as high concentration in Stevia leaf tissue, has made them the subject of research interest for over 100 years. Steviol glycosides are diterpenoids whose biosynthetic pathways share four steps in common with gibberellic acid formation. The convergence of genomics and plant biochemistry has led to the rapid elucidation of the genes coding for the various enzymes in the biosynthetic pathway. Functional characterization of the enzymes coded for by those genes is on-going. The first committed step in the pathway is the synthesis of the aglycone steviol and the various glycosides found in the leaf tissue result from the elaboration of steviol by a number of glucosyltransferases.

  13. Flavonol Intake and Cognitive Decline in Middle-Aged Adults.

    PubMed

    Root, Martin; Ravine, Erin; Harper, Anne

    2015-12-01

    Cognitive decline occurs with age and may be slowed by dietary measures, including increased intake of dietary phytochemicals. However, evidence from large and long-term studies of flavonol intake is limited. Dietary intakes of flavonols were assessed from a large biracial study of 10,041 subjects, aged 45-64, by analysis of a food frequency questionnaire administered at visit 1 of triennial visits. Cognitive function was assessed at visits 2 and 4 with the following three cognitive performance tests: the delayed word recall test, the revised Wechsler Adult Intelligence Scale digit symbol subtest, and the word fluency test of the Multilingual Aphasia Examination. The change in each score over 6 years was calculated, and a combined standardized change score was calculated. Generalized linear models controlled for age, ethnicity, gender, education level, energy intake, current smoking, physical activity, body mass index, diabetes, and vitamin C intake. Total flavonols across quintiles of intake were positively associated with preserved combined cognitive function (P<.001). This pattern with preserved combined cognitive function was consistent for the three major individual flavonols in the diet, myricetin, kaempferol, and quercetin (each P<.001). The positive association with total flavonols was strongest for the digit symbol subtest (P<.001). In this cohort, flavonol intake was correlated with protected cognitive function over time.

  14. Acyl-Lipid Metabolism

    PubMed Central

    Li-Beisson, Yonghua; Shorrosh, Basil; Beisson, Fred; Andersson, Mats X.; Arondel, Vincent; Bates, Philip D.; Baud, Sébastien; Bird, David; DeBono, Allan; Durrett, Timothy P.; Franke, Rochus B.; Graham, Ian A.; Katayama, Kenta; Kelly, Amélie A.; Larson, Tony; Markham, Jonathan E.; Miquel, Martine; Molina, Isabel; Nishida, Ikuo; Rowland, Owen; Samuels, Lacey; Schmid, Katherine M.; Wada, Hajime; Welti, Ruth; Xu, Changcheng; Zallot, Rémi; Ohlrogge, John

    2010-01-01

    Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables. PMID:22303259

  15. Acyl-Lipid Metabolism

    PubMed Central

    Li-Beisson, Yonghua; Shorrosh, Basil; Beisson, Fred; Andersson, Mats X.; Arondel, Vincent; Bates, Philip D.; Baud, Sébastien; Bird, David; DeBono, Allan; Durrett, Timothy P.; Franke, Rochus B.; Graham, Ian A.; Katayama, Kenta; Kelly, Amélie A.; Larson, Tony; Markham, Jonathan E.; Miquel, Martine; Molina, Isabel; Nishida, Ikuo; Rowland, Owen; Samuels, Lacey; Schmid, Katherine M.; Wada, Hajime; Welti, Ruth; Xu, Changcheng; Zallot, Rémi; Ohlrogge, John

    2013-01-01

    Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables. PMID:23505340

  16. Flavonol pentaglycosides of Cordyla (Leguminosae: Papilionoideae: Swartzieae): distribution and taxonomic implications.

    PubMed

    Veitch, Nigel C; Kite, Geoffrey C; Lewis, Gwilym P

    2008-09-01

    A survey of foliar flavonoids in the swartzioid legume genus Cordyla s.l. revealed that three species, C. haraka, C. pinnata and C. richardii, were rich in flavonol pentaglycosides. Their structures were elucidated by spectroscopic and chemical methods as the 3-O-alpha-L-rhamnopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->2)[alpha-L-rhamnopyranosyl(1-->6)]-beta-D-galactopyranoside-7-O-alpha-L-rhamnopyranosides of quercetin and kaempferol (cordylasins A and B, respectively). These compounds were not found in the remaining species, C. africana, C. densiflora, C. madagascariensis (two subspecies) and C. somalensis, which exhibited different profiles of flavonoid glycosides. The distribution of flavonol pentaglycosides in Cordyla s.l. does not support a recent proposal to place both C. haraka and C. madagascariensis in the genus Dupuya [Kirkbride, J.H., 2005. Dupuya, a new genus of Malagasy legumes (Fabaceae). Novon 15, 305-314]. The generic relationship between Cordyla s.l. and Mildbraediodendron is also reassessed on the basis of chemical characters, as the O-linked tetrasaccharide that characterises cordylasins A and B is the same as that found in mildbraedin (kaempferol 3-O-alpha-l-rhamnopyranosyl(1-->3)-alpha-l-rhamnopyranosyl(1-->2)[alpha-l-rhamnopyranosyl(1-->6)]-beta-D-galactopyranoside), the main foliar flavonoid of Mildbraediodendron excelsum. Mildbraedin itself was found to be a minor constituent of leaflet extracts of C. haraka, C. pinnata and C. richardii, and a major constituent of C. somalensis.

  17. Auxin and ethylene induce flavonol accumulation through distinct transcriptional networks.

    PubMed

    Lewis, Daniel R; Ramirez, Melissa V; Miller, Nathan D; Vallabhaneni, Prashanthi; Ray, W Keith; Helm, Richard F; Winkel, Brenda S J; Muday, Gloria K

    2011-05-01

    Auxin and ethylene are key regulators of plant growth and development, and thus the transcriptional networks that mediate responses to these hormones have been the subject of intense research. This study dissected the hormonal cross talk regulating the synthesis of flavonols and examined their impact on root growth and development. We analyzed the effects of auxin and an ethylene precursor on roots of wild-type and hormone-insensitive Arabidopsis (Arabidopsis thaliana) mutants at the transcript, protein, and metabolite levels at high spatial and temporal resolution. Indole-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) differentially increased flavonol pathway transcripts and flavonol accumulation, altering the relative abundance of quercetin and kaempferol. The IAA, but not ACC, response is lost in the transport inhibitor response1 (tir1) auxin receptor mutant, while ACC responses, but not IAA responses, are lost in ethylene insensitive2 (ein2) and ethylene resistant1 (etr1) ethylene signaling mutants. A kinetic analysis identified increases in transcripts encoding the transcriptional regulators MYB12, Transparent Testa Glabra1, and Production of Anthocyanin Pigment after hormone treatments, which preceded increases in transcripts encoding flavonoid biosynthetic enzymes. In addition, myb12 mutants were insensitive to the effects of auxin and ethylene on flavonol metabolism. The equivalent phenotypes for transparent testa4 (tt4), which makes no flavonols, and tt7, which makes kaempferol but not quercetin, showed that quercetin derivatives are the inhibitors of basipetal root auxin transport, gravitropism, and elongation growth. Collectively, these experiments demonstrate that auxin and ethylene regulate flavonol biosynthesis through distinct signaling networks involving TIR1 and EIN2/ETR1, respectively, both of which converge on MYB12. This study also provides new evidence that quercetin is the flavonol that modulates basipetal auxin transport.

  18. Variants of glycoside hydrolases

    DOEpatents

    Teter, Sarah; Ward, Connie; Cherry, Joel; Jones, Aubrey; Harris, Paul; Yi, Jung

    2013-02-26

    The present invention relates to variants of a parent glycoside hydrolase, comprising a substitution at one or more positions corresponding to positions 21, 94, 157, 205, 206, 247, 337, 350, 373, 383, 438, 455, 467, and 486 of amino acids 1 to 513 of SEQ ID NO: 2, and optionally further comprising a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2 a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2, wherein the variants have glycoside hydrolase activity. The present invention also relates to nucleotide sequences encoding the variant glycoside hydrolases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  19. Variants of glycoside hydrolases

    DOEpatents

    Teter, Sarah; Ward, Connie; Cherry, Joel; Jones, Aubrey; Harris, Paul; Yi, Jung

    2011-04-26

    The present invention relates to variants of a parent glycoside hydrolase, comprising a substitution at one or more positions corresponding to positions 21, 94, 157, 205, 206, 247, 337, 350, 373, 383, 438, 455, 467, and 486 of amino acids 1 to 513 of SEQ ID NO: 2, and optionally further comprising a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2 a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2, wherein the variants have glycoside hydrolase activity. The present invention also relates to nucleotide sequences encoding the variant glycoside hydrolases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  20. Quinoid glycosides from Forsythia suspensa.

    PubMed

    Li, Chang; Dai, Yi; Zhang, Shu-Xiang; Duan, Ying-Hui; Liu, Ming-Li; Chen, Liu-Yuan; Yao, Xin-Sheng

    2014-08-01

    Phytochemical investigation on Forsythia suspensa (Thunb.) Vahl afforded 10 compounds, including quinoid glycosides, lignan glycosides, phenylethanoid glycoside and allylbenzene glycoside together with 13 known ones. Their structures were established based on extensive spectroscopic data analyses, including IR, UV, HRESIMS, 1D NMR and 2D NMR. Absolute configurations were determined by ECD calculation method and chemical degradation. In addition, all compounds were evaluated for their antiviral activity against influenza A (H1N1) virus and several were further evaluated against respiratory syncytial virus (RSV) in vitro. Among them, two previously known compounds showed significant activities against RSV with EC50 values of 3.43 and 6.72 μM.

  1. Transgenic rice seed expressing flavonoid biosynthetic genes accumulate glycosylated and/or acylated flavonoids in protein bodies

    PubMed Central

    Ogo, Yuko; Mori, Tetsuya; Nakabayashi, Ryo; Saito, Kazuki; Takaiwa, Fumio

    2016-01-01

    Plant-specialized (or secondary) metabolites represent an important source of high-value chemicals. In order to generate a new production platform for these metabolites, an attempt was made to produce flavonoids in rice seeds. Metabolome analysis of these transgenic rice seeds using liquid chromatography-photodiode array-quadrupole time-of-flight mass spectrometry was performed. A total of 4392 peaks were detected in both transgenic and non-transgenic rice, 20–40% of which were only detected in transgenic rice. Among these, 82 flavonoids, including 37 flavonols, 11 isoflavones, and 34 flavones, were chemically assigned. Most of the flavonols and isoflavones were O-glycosylated, while many flavones were O-glycosylated and/or C-glycosylated. Several flavonoids were acylated with malonyl, feruloyl, acetyl, and coumaroyl groups. These glycosylated/acylated flavonoids are thought to have been biosynthesized by endogenous rice enzymes using newly synthesized flavonoids whose biosynthesis was catalysed by exogenous enzymes. The subcellular localization of the flavonoids differed depending on the class of aglycone and the glycosylation/acylation pattern. Therefore, flavonoids with the intended aglycones were efficiently produced in rice seeds via the exogenous enzymes introduced, while the flavonoids were variously glycosylated/acylated by endogenous enzymes. The results suggest that rice seeds are useful not only as a production platform for plant-specialized metabolites such as flavonoids but also as a tool for expanding the diversity of flavonoid structures, providing novel, physiologically active substances. PMID:26438413

  2. Transgenic rice seed expressing flavonoid biosynthetic genes accumulate glycosylated and/or acylated flavonoids in protein bodies.

    PubMed

    Ogo, Yuko; Mori, Tetsuya; Nakabayashi, Ryo; Saito, Kazuki; Takaiwa, Fumio

    2016-01-01

    Plant-specialized (or secondary) metabolites represent an important source of high-value chemicals. In order to generate a new production platform for these metabolites, an attempt was made to produce flavonoids in rice seeds. Metabolome analysis of these transgenic rice seeds using liquid chromatography-photodiode array-quadrupole time-of-flight mass spectrometry was performed. A total of 4392 peaks were detected in both transgenic and non-transgenic rice, 20-40% of which were only detected in transgenic rice. Among these, 82 flavonoids, including 37 flavonols, 11 isoflavones, and 34 flavones, were chemically assigned. Most of the flavonols and isoflavones were O-glycosylated, while many flavones were O-glycosylated and/or C-glycosylated. Several flavonoids were acylated with malonyl, feruloyl, acetyl, and coumaroyl groups. These glycosylated/acylated flavonoids are thought to have been biosynthesized by endogenous rice enzymes using newly synthesized flavonoids whose biosynthesis was catalysed by exogenous enzymes. The subcellular localization of the flavonoids differed depending on the class of aglycone and the glycosylation/acylation pattern. Therefore, flavonoids with the intended aglycones were efficiently produced in rice seeds via the exogenous enzymes introduced, while the flavonoids were variously glycosylated/acylated by endogenous enzymes. The results suggest that rice seeds are useful not only as a production platform for plant-specialized metabolites such as flavonoids but also as a tool for expanding the diversity of flavonoid structures, providing novel, physiologically active substances.

  3. Medicinal flowers. XXII. Structures of chakasaponins V and VI, chakanoside I, and chakaflavonoside A from flower buds of Chinese tea plant (Camellia sinensis).

    PubMed

    Yoshikawa, Masayuki; Sugimoto, Sachiko; Nakamura, Seikou; Matsuda, Hisashi

    2008-09-01

    Two acylated oleanane-type triterpene oligoglycosides, chakasaponins V and VI, an aromatic glycoside, chakanoside I, and an acylated flavonol oligoglycoside, chakaflavonoside A, were isolated from the flower buds of Chinese tea plant [Camellia sinensis (L.) O. KUNTZE]. The chemical structures of those new glycosides were elucidated on the basis of chemical and physicochemical evidence.

  4. Glycoside vs. Aglycon: The Role of Glycosidic Residue in Biological Activity

    NASA Astrophysics Data System (ADS)

    Křen, Vladimír

    A large number of biologically active compounds are glycosides. Sometimes the glycosidic residue is crucial for their activity, in other cases glycosylation only improves pharmacokinetic parameters. Recent developments in molecular glycobiology brought better understanding of aglycon vs. glycoside activities, and made possible the development of new, more active or more effective glycodrugs based on these findings - a very illustrative recent example is vancomycin. The new enzymatic methodology "glycorandomization" enabled preparation of glycoside libraries and opened up paths to the preparation of optimized or entirely novel glycoside antibiotics. This chapter deals with an array of glycosidic compounds currently used in medicine but also covers the biological activity of some glycosidic metabolites of known drugs. The chapter discusses glycosides of vitamins, polyphenolic glycosides (flavonoids), alkaloid glycosides, glycosides of antibiotics, glycopeptides, cardiac glycosides, steroid and terpenoid glycosides etc. The physiological role of the glycosyl moiety and structure-activity relations (SAR) in the glycosidic moiety (-ies) are also discussed.

  5. Differential stress-response expression of two flavonol synthase genes and accumulation of flavonols in tartary buckwheat.

    PubMed

    Li, Xiaohua; Kim, Yeon Bok; Kim, Yeji; Zhao, Shicheng; Kim, Haeng Hoon; Chung, Eunsook; Lee, Jai-Heon; Park, Sang Un

    2013-12-15

    Flavonoids are ubiquitously present in plants and play important roles in these organisms as well as in the human diet. Flavonol synthase (FLS) is a key enzyme of the flavonoid biosynthetic pathway, acting at the diverging point into the flavonol subclass branch. We isolated and characterized a FLS isoform gene, FtFLS2, from tartary buckwheat (Fagopyrum tataricum). FtFLS2 shares 48% identity and 67% similarity with the previously reported FtFLS1, whereas both genes share 47-65% identity and 65-69% similarity with FLSs from other plant species. Using quantitative real-time PCR and high-performance liquid chromatography (HPLC), the expression of FtFLS1/2 and the production of 3 main flavonols (kaempferol, myricetin and quercetin) was detected in roots, leaves, stems, flowers and different stages of developing seeds. The relationship between the expression of the 2 FLS genes and the accumulation of the 3 basic flavonols was analyzed in 2 tartary buckwheat cultivars. FtFLS1 and FtFLS2 exhibited differential transcriptional levels between the tartary buckwheat cultivars 'Hokkai T10' and 'Hokkai T8'. Generally, higher transcript levels of FtFLS1 and FtFLS2 and a higher amount of flavonols were observed in the 'Hokkai T10' cultivar than 'Hokkai T8'. The content of flavonols showed tissue-specific accumulation between the 2 cultivars. The transcription of FtFLS1 was inhibited by the exogenous application of abscisic acid (ABA), salicylic acid (SA) and sodium chloride (NaCl), while FtFLS2 was not affected by ABA but up-regulated by SA and NaCl. These data indicate that the 2 FtFLS isoforms of buckwheat have different functions in the response of buckwheat to environmental stress.

  6. Two new phenylpropanoid glycosides with interesterification from Scrophularia dentata Royle ex Benth

    NASA Astrophysics Data System (ADS)

    Zhang, Liuqiang; Yang, Zhuo; Jia, Qi; Dorje, Gaawe; Zhao, Zhili; Guo, Fujiang; Li, Yiming

    2013-10-01

    Two new phenylpropanoid glycosides (1-2), along with seven known ones (3-9), were isolated from the whole plant of Scrophularia dentata Royle ex Benth. Their structures were elucidated by spectroscopic methods. Among them, compounds 1 and 2 failed to separated, because they can easily transform into each other by acyl migrant reaction. In this paper, the interesterification mechanism was discussed firstly and the rule can be used in the similar structure elucidation in future.

  7. Flavonoid glycosides from Eugenia jambos.

    PubMed

    Slowing, K; Söllhuber, M; Carretero, E; Villar, A

    1994-09-01

    Two flavonol diglycosides isolated from the leaves of Eugenia jambos were characterized as quercetin and myricetin 3-O-beta-D-xylopyranosyl(1-->2) alpha-L-rhamnopyranosides by means of spectral analyses applying 2D NMR techniques and NOE experiments.

  8. A flavonoid 3-O-glucoside:2″-O-glucosyltransferase responsible for terminal modification of pollen-specific flavonols in Arabidopsis thaliana

    PubMed Central

    Yonekura-Sakakibara, Keiko; Nakabayashi, Ryo; Sugawara, Satoko; Tohge, Takayuki; Ito, Takuya; Koyanagi, Misuzu; Kitajima, Mariko; Takayama, Hiromitsu; Saito, Kazuki

    2014-01-01

    Flavonol 3-O-diglucosides with a 1→2 inter-glycosidic linkage are representative pollen-specific flavonols that are widely distributed in plants, but their biosynthetic genes and physiological roles are not well understood. Flavonoid analysis of four Arabidopsis floral organs (pistils, stamens, petals and calyxes) and flowers of wild-type and male sterility 1 (ms1) mutants, which are defective in normal development of pollen and tapetum, showed that kaempferol/quercetin 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosides accumulated in Arabidopsis pollen. Microarray data using wild-type and ms1 mutants, gene expression patterns in various organs, and phylogenetic analysis of UDP-glycosyltransferases (UGTs) suggest that UGT79B6 (At5g54010) is a key modification enzyme for determining pollen-specific flavonol structure. Kaempferol and quercetin 3-O-glucosyl-(1→2)-glucosides were absent from two independent ugt79b6 knockout mutants. Transgenic ugt79b6 mutant lines transformed with the genomic UGT79B6 gene had the same flavonoid profile as wild-type plants. Recombinant UGT79B6 protein converted kaempferol 3-O-glucoside to kaempferol 3-O-glucosyl-(1→2)-glucoside. UGT79B6 recognized 3-O-glucosylated/galactosylated anthocyanins/flavonols but not 3,5- or 3,7-diglycosylated flavonoids, and prefers UDP-glucose, indicating that UGT79B6 encodes flavonoid 3-O-glucoside:2″-O-glucosyltransferase. A UGT79B6-GUS fusion showed that UGT79B6 was localized in tapetum cells and microspores of developing anthers. PMID:24916675

  9. Determination of flavone C-glycosides in tea.

    PubMed

    Engelhardt, U H; Finger, A; Kuhr, S

    1993-09-01

    An HPLC method for the determination of flavone C-glycosides (FCG) from black tea has been developed. Sample clean-up was accomplished by means of polyamide column chromatography, followed by enzyme hydrolysis of interfering compounds such was flavonol glycosides and a second polyamide column chromatographic step. Using HPLC with gradient elution and photodiode array detection eight FCG were separated. Seven FCG were isolated by means of preparative HPLC. Identification was carried out using co-chromatography, FAB(Fast Atom Bombardment)-mass spectrometry and various nuclear magnetic resonance techniques. Apigenin 6-C-glucosyl-8-arabinoside (schaftoside) and apigenin 6-C-arabinosyl-8-C-glucoside (isoschaftoside) as well as luteolin 8-C-glucoside (orientin) and luteolin 6-C-glucoside (isoorientin) have been detected in tea for the first time. Three of the other compounds have been identified as apigenin 8-C-glucoside (vitexin), apigenin 6-C-glucoside (isovitexin) and apigenin 6,8-di-C-glucoside (vicenin-2). Their occurrence in tea has been previously reported. From its UV spectrum another compound was concluded to be an apigenin glycoside. The FCG were quantified in a variety of teas of different origins (16 black, two green and one oolong). The total amounts of the FCG were 0.48-2.69 g/kg dry weight. The FCG pattern of teas of different origins were similar to each other and no origin-dependent characteristics have yet been observed. Small amounts of FCG (1.2-2.2 mg/kg) were detected in hydrolysates of high relative molecular mass fractions (Mr > 5000) of a black tea liquor.

  10. Cytotoxicity of pregnane glycosides of Cynanchum otophyllum.

    PubMed

    Zhang, Mi; Li, Xiang; Xiang, Cheng; Qin, Yi; He, Jing; Li, Bao-Cai; Li, Peng

    2015-12-01

    Fourteen new pregnane glycosides, including nine caudatin glycosides (1-9), three qinyangshengenin glycosides (10-12), one kidjoranin glycosides (13) and one gagaminin glycosides (14), along with twelve known analogs (15-26) were isolated from roots of Cynanchum otophyllum Schneid. Their structures were deduced by detailed analysis of 1D and 2D NMR spectra, as well as HRESIMS. In this study, all pregnane glycosides obtained (1-26) were evaluated for their cytotoxic activities using three cancer cell lines (HepG2, Hela, U251). As results, except 6 and 10, other twenty-four pregnane glycosides showed cytotoxicities at different degrees against three cell lines.

  11. Preparative isolation and purification of five flavonoid glycosides and one benzophenone galloyl glycoside from Psidium guajava by high-speed counter-current chromatography (HSCCC).

    PubMed

    Zhu, Yindi; Liu, Yue; Zhan, Ying; Liu, Lin; Xu, Yajuan; Xu, Tunhai; Liu, Tonghua

    2013-12-16

    Psidium guajava leaves have a diverse phytochemical composition including flavonoids, phenolics, meroterpenoids and triterpenes, responsible for the biological activities of the medicinal parts. In particular, flavonol glycosides show beneficial effects on type II diabetes mellitus. A simple and efficient HSCCC method has been developed for the preparative separation of five flavonoid glycosides and one diphenylmethane glycoside from P. guajava. A solvent system composed of n-hexane-ethyl acetate-methanol-water (0.7:4:0.8:4, v/v/v/v) was optimized for the separation. The upper phase was used as the stationary phase, and the lower phase was used as the mobile phase. Under the optimized conditions, hyperoside (15.3 mg), isoquercitrin (21.1 mg), reynoutrin (65.2 mg), quercetin-3-O-β-D-arabinopyranoside (71.7 mg), quercetin-3-O-α-L-arabinofuranoside (105.6 mg) and 2,4,6-trihydroxy-3,5-dimethylbenzophenone 4-O-(6''-O-galloyl)-β-D-glucopyranoside (98.4 mg) were separated from crude sample (19.8 g). The structures of all the isolates were identified by ESI-MS, 1H- and 13C-NMR analyses and their purities (>95%) were determined using HPLC.

  12. Acylation of Ferrocene: A Greener Approach

    ERIC Educational Resources Information Center

    Birdwhistell, Kurt R.; Nguyen, Andy; Ramos, Eric J.; Kobelja, Robert

    2008-01-01

    The acylation of ferrocene is a common reaction used in organic laboratories to demonstrate Friedel-Crafts acylation and the purification of compounds using column chromatography. This article describes an acylation of ferrocene experiment that is more eco-friendly than the conventional acylation experiment. The traditional experiment was modified…

  13. Iron reduction potentiates hydroxyl radical formation only in flavonols.

    PubMed

    Macáková, Kateřina; Mladěnka, Přemysl; Filipský, Tomáš; Říha, Michal; Jahodář, Luděk; Trejtnar, František; Bovicelli, Paolo; Proietti Silvestri, Ilaria; Hrdina, Radomír; Saso, Luciano

    2012-12-15

    Flavonoids, substantial components of the human diet, are generally considered to be beneficial. However, they may possess possible pro-oxidative effects, which could be based on their reducing potential. The aims of this study were to evaluate the ability of 26 flavonoids to reduce ferric ions at relevant pH conditions and to find a possible relationship with potentiation of hydroxyl radical production. A substantial ferric ions reduction was achieved under acidic conditions, particularly by flavonols and flavanols with the catecholic ring B. Apparently corresponding bell-shaped curves displaying the pro-oxidant effect of flavonols quercetin and kaempferol on iron-based Fenton reaction were documented. Several flavonoids were efficient antioxidants at very low concentrations but rather inefficient or pro-oxidative at higher concentrations. Flavonols, morin and rutin were progressively pro-oxidant, while 7-hydroxyflavone and hesperetin were the only flavonoids with dose-dependent inhibition of hydroxyl radical production. Conclusively, administration of flavonoids may lead to unpredictable consequences with few exceptions.

  14. Structure-activity relationship studies of flavonol analogues on pollen germination.

    PubMed

    Forbes, Alaina M; Meier, G Patrick; Haendiges, Stacey; Taylor, Loverine P

    2014-03-12

    Flavonoids are polyphenolic compounds required in the fertilization process in many, if not all, plants. However, the exact biological mechanism(s) and the interacting proteins are unknown. To determine the characteristics important in activating or inhibiting the pollination sequence, a structure-activity relationship analysis of natural and synthetic flavonols was conducted. Flavonol analogues were synthesized through a modified "one-pot" procedure that utilized a Baker-Venkataraman type rearrangement and a Suzuki-Miyaura cross-coupling of a halo-flavonol with an organotrifluoroborate. Of the flavonols tested, kaempferol was the only compound to act as a full agonist. The other smaller, less sterically hindered flavonols (galangin, kaempferide, and 4'-methyl flavonol) acted as partial agonists. Larger more hydrophobic flavonol analogues (3'- and 4'-benzoyl, 3'- and 4'-phenyl, and 3'- and 4'-iodo flavonols) had minimal or no agonist activity. Competition assays between kaempferol and these minimally activating flavonols showed that these analogues inhibited the action of kaempferol in a manner consistent with noncompetitive antagonism. The results suggest that steric hindrance is the most important factor in determining a good agonist. Hydrogen bonding also had a positive effect as long as the substituent did not cause any steric hindrance.

  15. Flavanone glycosides as oviposition stimulants in a papilionid butterfly,Papilio protenor.

    PubMed

    Honda, K

    1986-10-01

    Identification of chemical compounds responsible for the oviposition behavior in a Rutaceae feeder,Papilio protenor demetrius, was undertaken with the epicarp of sour orange (Citrus natsudaidai) which exhibited potent stimulatory activity as did its leaves for egg-laying by the females. The stimulants were present in the hydrosoluble fraction, and the kairomonal activity displayed by the peel was regarded as originating from the synergistic effect of the total chemical complex. One of the active compounds was identified as a flavanone glycoside, naringin (naringenin-7β-neohesperidoside), which, although showing no appreciable effectiveness when bioassayed alone, elicited positive response at the concentration of 0.2% either when admixed with other unidentified components or provided the females had been conditioned with them in advance. Another flavanone glycoside, hesperidin (hesperetin-7β-rutinoside) that was contained in a trace amount in the peel also had a positive effect comparable to that of naringin under similar conditions, while their corresponding aglycones were less active or inactive. In contrast, a flavone glycoside, rhoifolin, coexisting in the peel, and some other flavones and flavonols tested as possible candidates for oviposition stimulants were all found entirely ineffective.

  16. Effects of flavonol-rich green tea cultivar (Camellia sinensis L.) on plasma oxidized LDL levels in hypercholesterolemic mice.

    PubMed

    Nomura, Sachiko; Monobe, Manami; Ema, Kaori; Matsunaga, Akiko; Maeda-Yamamoto, Mari; Horie, Hideki

    2016-01-01

    To examine the possible benefits of tea flavonols, we compared anti-atherogenic effects between common and flavonol-rich tea cultivars. The tea infusion made from a flavonol-rich cultivar, but not a common cultivar, significantly decreased the plasma oxidized low-density lipoprotein level in mice fed a high-cholesterol diet. The result suggests that tea flavonols have the potential to protect against cardiovascular diseases.

  17. Anti-inflammatory activity of flavonol glycosides from Erythrospermum monticolum depending on single or repeated local TPA administration.

    PubMed

    del Carmen Recio, M; Giner, R M; Máñez, S; Talens, A; Cubells, L; Gueho, J; Julien, H R; Hostettmann, K; Rios, J L

    1995-12-01

    Two anti-inflammatory principles were isolated from the methanol extract of the leaves of Erythrospermum monticolum (Flacourtiaceae). The isolation was based on a guided bioassay of the inhibitory activity on TPA-induced ear edema in mice. These compounds were identified as quercetin 3-O-xylosyl(1-->2) rhamnoside and quercetin 3-O-rhamnoside. In addition, their effects on a chronic topic inflammation model were evaluated.

  18. Constituents with radical scavenging effect from Opuntia dillenii: structures of new alpha-pyrones and flavonol glycoside.

    PubMed

    Qiu, Yingkun; Chen, Yingjie; Pei, Yupin; Matsuda, Hisashi; Yoshikawa, Masayuki

    2002-11-01

    The aqueous ethanolic extract from the fresh stems of Opuntia dillenii HAW. showed potent radical scanvenging activity. Three new compounds, opuntioside I, 4-ethoxyl-6-hydroxymethyl-alpha-pyrone, and kaempferol 7-O-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranoside, were isolated from the extract. The structures of the new compounds were determined on the basis of chemical and physicochemical evidence and the radical scavenging effects of principal constituents were examined.

  19. Ghrelin acylation and metabolic control.

    PubMed

    Al Massadi, O; Tschöp, M H; Tong, J

    2011-11-01

    Since its discovery, many physiologic functions have been ascribed to ghrelin, a gut derived hormone. The presence of a median fatty acid side chain on the ghrelin peptide is required for the binding and activation of the classical ghrelin receptor, the growth hormone secretagogue receptor (GHSR)-1a. Ghrelin O-acyl transferase (GOAT) was recently discovered as the enzyme responsible for this acylation process. GOAT is expressed in all tissues that have been found to express ghrelin and has demonstrated actions on several complex endocrine organ systems such as the hypothalamus-pituitary-gonadal, insular and adrenal axis as well as the gastrointestinal (GI) tract, bone and gustatory system. Ghrelin acylation is dependent on the function of GOAT and the availability of substrates such as proghrelin and short- to medium-chain fatty acids (MCFAs). This process is governed by GOAT activity and has been shown to be modified by dietary lipids. In this review, we provided evidence that support an important role of GOAT in the regulation of energy homeostasis and glucose metabolism by modulating acyl ghrelin (AG) production. The relevance of GOAT and AG during periods of starvation remains to be defined. In addition, we summarized the recent literature on the metabolic effects of GOAT specific inhibitors and shared our view on the potential of targeting GOAT for the treatment of metabolic disorders such as obesity and type 2 diabetes.

  20. Chemical Reporters for Exploring Protein Acylation

    PubMed Central

    Thinon, Emmanuelle; Hang, Howard C.

    2015-01-01

    Proteins are acylated by a variety of metabolites that regulates many important cellular pathways in all kingdoms of life. Acyl groups in cells can vary in structure from the smallest unit, acetate, to modified long chain fatty acids, all of which can be activated and covalently attached to diverse amino acid side chains and consequently modulate protein function. For example, acetylation of Lys residues can alter the charge state of proteins and generate new recognition elements for protein–protein interactions. Alternatively, long chain fatty-acylation targets proteins to membranes and enables spatial control of cell signalling. To facilitate the analysis of protein acylation in biology, acyl analogues bearing alkyne or azide tags have been developed that enable fluorescent imaging and proteomic profiling of modified proteins using bioorthogonal ligation methods. Herein, we summarize the currently available acylation chemical reporters and highlight their utility to discover and quantify the roles of protein acylation in biology. PMID:25849926

  1. Steroidal glycosides from Reineckia carnea.

    PubMed

    Song, Xiaomei; Zhang, Dongdong; He, Hao; Li, Yuze; Yang, Xinjie; Deng, Chong; Tang, Zhishu; Cui, Jiucheng; Yue, Zhenggang

    2015-09-01

    Three new steroidal glycosides (1-3) and a novel natural product 4 firstly obtained from a plant source, together with two known steroidal glycosides (5-6) have been isolated from the whole plant of Reineckia carnea. Their structures were determined by physicochemical properties and spectroscopic methods, and their cytotoxic activities against human 1299 tumor cells were evaluated by the MTT method. Compounds 4, 5 and 6 exhibited cytotoxicity with IC50 values of 50.3 μmol·L(-1), 67.2 μmol·L(-1) and 61.8 μmol·L(-1), while compounds 1, 2, and 3 showed no cytotoxicity with the cells.

  2. Microbial hydrolysis of steviol glycosides.

    PubMed

    Renwick, A G; Tarka, S M

    2008-07-01

    A review of the role of gut microbiota in the metabolism of the steviol glycosides, stevioside and rebaudioside A, indicates that they are not absorbed intact but undergo hydrolysis by the intestinal microflora to steviol. Steviol is not metabolized by the intestinal flora and is absorbed from the intestine. The rate of hydrolysis for stevioside is greater than for rebaudioside A. Recent studies using mass spectrometry have shown that steviol-16,17-epoxide is not a microbial metabolite of steviol glycosides. Bacteroides species are primarily responsible for hydrolysis via their beta-glucosidase activity. Fecal incubation studies with both human and animal mixed flora provide similar results, and this indicates that the rat is an appropriate model for studies on steviol glycosides. Given the similarity in the microbial metabolism of stevioside and rebaudioside A with the formation of steviol as the single hydrolysis product that is absorbed from the intestinal tract, the toxicological data on stevioside are relevant to the risk assessment of rebaudioside A.

  3. The chemical synthesis of aryltetralin glycosides.

    PubMed

    Sun, Jian-Song; Liu, Hui; Guo, Xiao-Hong; Liao, Jin-Xi

    2016-01-28

    Led by etoposide and teniposide, the synthesis of aryltetralin glycosides has been experiencing flourishing development in the past five decades. Herein, a review focusing on the total synthesis of aryltetralin glycosides is provided. The main body of this review is composed of two parts, one is the enantioselective synthesis of aryltetralin derivatives and the other one is the construction of key glycosidic linkages. In each part the contents are organised based on the different strategies or protocols applied in the original documents. The total synthesis of aryltetralin glycosides represents the developing direction of this field, and sooner or later will replace the currently applied semi-total synthesis method, using the aglycon residue acquired directly from natural sources. This account provides a comprehensive and deep insight into the field of aryltetralin glycoside synthesis for chemists who have the intention of committing themselves to the development of aryltetralin glycoside medicine.

  4. Aroma Glycosides in Grapes and Wine.

    PubMed

    Liu, Jibin; Zhu, Xiao-Lin; Ullah, Niamat; Tao, Yong-Sheng

    2017-02-01

    The major aroma components in grapes and wine include free volatile compounds and glycosidic nonvolatile compounds. The latter group of compounds is more than 10 times abundant of the former, and constitutes a big aroma reserve in grapes and wine. This review summarizes the research results obtained recently for the identification of aroma glycosides in grapes and wine, including grape glycoside structures, differences in aroma glycosides among grape varieties, hydrolysis mechanisms, and the factors that influence them. It also presents the analytical techniques used to identify the glycosidic aroma precursors. The operational strategies, challenges, and improvements of each step encountered in the analysis of glycosidic aroma precursors are described. This review intends to provide a convenient reference for researchers interested in the methods used for the determination of the aroma glucosides composition and the recognition of their chemical structures.

  5. Facile synthesis of aminooxy glycosides by gold(III)-catalyzed glycosidation.

    PubMed

    Thadke, Shivaji A; Neralkar, Mahesh; Hotha, Srinivas

    2016-07-22

    The O-glycosidation of hydroxysuccinimides and hydroxyphthalimides with a variety of aldose derived propargyl 1,2-orthoesters under the gold(III)-catalyzed glycosidation conditions is reported. A wide range of hydroxysuccinimidyl and hydroxyphthalimidyl glycosides were synthesized from corresponding glycosyl orthoesters including glucosyl, mannosyl, galactosyl, ribofuranosyl, arabinofuranosyl, lyxofuranosyl and xylofuranosyl using gold catalysis repertoire. The protocol is identified to be compatible for the synthesis of aminooxy glycosides of higher oligosaccharides as well.

  6. Evolution and Expression of Tandem Duplicated Maize Flavonol Synthase Genes

    PubMed Central

    Falcone Ferreyra, María Lorena; Casas, María Isabel; Questa, Julia Irene; Herrera, Andrea Lorena; DeBlasio, Stacy; Wang, Jing; Jackson, David; Grotewold, Erich; Casati, Paula

    2012-01-01

    Flavonoids are specialized compounds widely distributed and with diverse functions throughout the plant kingdom and with several benefits for human health. In particular, flavonols, synthesized by flavonol synthase (FLS), protect plants against UV-B radiation and are essential for male fertility in maize and other plants. We have recently characterized a UV-B inducible ZmFLS1, corresponding to the first to be described in monocot plants. Interestingly, the new assembly of the B73 maize genome revealed the presence of a second putative FLS gene (ZmFLS2), with very high identity with ZmFLS1. ZmFLSs expression was analyzed in different maize tissues, and by combining electrophoretic mobility shift assays and transient expression experiments, we show that both genes are direct targets of anthocyanin (C1/PL1 + R/B) and 3-deoxy flavonoid (P1) transcriptional regulators. ZmFLS expression analyses show higher levels of both transcripts in high altitude landraces than inbred lines, and both genes are regulated by UV-B radiation in all lines analyzed. Moreover, the high sequence conservation of the ZmFLS promoters between maize lines suggests that the differences observed in ZmFLS expression are due to allelic variations in the transcription factors that regulate their activities. Finally, we generated pFLS1::FLS1-RFP transgenic plants and analyzed ZmFLS1 expression in different maize tissues; we found that this enzyme is localized in the ER and the perinuclear region. PMID:22654889

  7. Oxidation of the flavonol fisetin by polyphenol oxidase.

    PubMed

    Jiménez, M; Escribano-Cebrián, J; García-Carmona, F

    1998-11-27

    The present study demonstrates the antiradical efficiency of fisetin, a flavonol widely distributed in fruits and vegetables, by its ability to react with two different free radicals, ABTS; and DPPH;. The polyphenolic nature of fisetin led us to consider whether it might be oxidised by polyphenol oxidase (PPO), and the results reported show that it can be oxidised by PPO extracted and partially purified from broad bean seeds. The reaction was followed by recording spectral changes with time, with maximal spectral changes being observed at 282 nm (increase in absorbance) and at 362 nm (decrease). The presence of two isosbectic points (at 265 and 304 nm) suggested that only one absorbent product was formed. These spectral changes were not observed in the absence of PPO. The oxidation rate varied with the pH, reaching its highest value at pH 5.5. The fisetin oxidation rate increased in the presence of sodium dodecyl sulfate, an activator of polyphenol oxidase. Maximal activity was obtained at 0.87 mM sodium dodecyl sulfate. The following kinetic parameters were determined: Vmax=49 microM/min, Km=0.6 mM, Vmax/Km=8.2x10-2 min-1. Flavonol oxidation was inhibited by selective PPO inhibitors such as cinnamic acid (a classical competitive inhibitor, Ki=1.4 mM) and 4-hexylresorcinol, which behaved as a slow-binding inhibitor. The results reported show that fisetin oxidation was strictly dependent on the presence of polyphenol oxidase.

  8. New lignan glycosides from Justicia procumbens.

    PubMed

    Jin, Hong; Yang, Shu; Dong, Jun-Xing

    2017-01-01

    Four new lignan glycosides (1-4), named procumbenosides I, K, L, and M, together with cleistanthin B (5) reported for the first time in the genus Justicia, and 5 other known arylnaphthalene lignan glycosides (6-10) were isolated from the whole plant of Justicia procumbens. The structures of the new compounds were elucidated by extensive one-dimensional (1D) and two-dimensional (2D) NMR experiments and mass spectrometry. Procumbenoside M (4) was a rare sesquilignan glycoside never previously reported in the species of Justicia. The paper also provided insight into the conformational equilibria existing in the lignan glycosides of the plant.

  9. Bioconversion of steroid glycosides by Nocardia restricta.

    PubMed

    Belic, I; Kastelic-Suhadolc, T; Kralj, B

    1985-09-01

    The bioconversion of steroid alkaloid tomatine by Nocardia restricta yields the conjugate with lactic acid. We studied the bioconversion of some steroid glycosides without a nitrogen atom in the molecule to determine the effect of the nitrogen atom. The glycosides were of three different types: sterol glycosides, bufadienolide rhamnoside and steroid saponine. The results of bioconversions showed that Nocardia restricta converts steroid glycosides differently according to the sugar bound to the steroid aglycone. It can be concluded that in the absence of a nitrogen atom in the steroid molecule no conjugation with lactic acid by Nocardia restricta occurs.

  10. Lipoxygenase-inhibiting phenolic glycosides and monoterpene glycosides from Paeonia lactiflora.

    PubMed

    Zou, Liang; Hu, Lin-Feng; Guo, Yi-Dong; Song, Yu; Fu, Qiang

    2015-01-01

    The EtOH extract of the roots of Paeonia lactiflora afforded a new phenolic glycoside paenoside A (1) and a new monoterpene glycoside paeonin D (2), and five known monoterpene glycosides. Their structures were elucidated on the basis of spectroscopic means and hydrolysis products. All compounds displayed inhibitory potential against enzyme lipoxygenase.

  11. Fluorescent analysis of interaction of flavonols with hemoglobin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Sentchouk, V. V.; Bondaryuk, E. V.

    2007-09-01

    We have studied the fluorescent properties of flavonols (quercetin, fisetin, morin, rutin) with the aim of studying possible interaction with hemoglobin and bovine serum albumin (BSA). We observed an increase in the intensity of intrinsic fluorescence for all the flavonols except rutin in the presence of BSA. From the changes in the fluorescence spectra, we concluded that tautomeric forms are formed on interaction with hemoglobin. We determined the interconnection between the structure of related flavonols and their fluorescent properties on interaction with proteins, and we determined the binding constants for binding with BSA and hemoglobin.

  12. Identification and quantification of galloyl derivatives, flavonoid glycosides and anthocyanins in leaves of Pistacia lentiscus L.

    PubMed

    Romani, A; Pinelli, P; Galardi, C; Mulinacci, N; Tattini, M

    2002-01-01

    Separation, identification and quantification of polyphenols was carried out on leaves of Pistacia lentiscus L., an evergreen member of the family Anacardiaceae, using semi-preparative HPLC, HPLC-photodiode array detection and HPLC-MS analysis, together with 1H- and 13C NMR. Three major classes of secondary metabolites were detected: (i) gallic acid and galloyl derivatives of both glucose and quinic acid; (ii) flavonol glycosides, i.e. myricetin and quercetin glycosides; and (iii) anthocyanins, namely delphinidin 3-O-glucoside and cyanidin 3-O-glucoside. Low amounts of catechin were also detected. The concentration of galloyl derivatives was extremely high, representing 5.3% of the leaf dry weight, and appreciable amounts of myricetin derivatives were also detected (1.5% on a dry weight basis). These findings may be useful in establishing a relationship between the chemical composition of the leaf extract and the previously reported biological activity of P. lentiscus, and may also assign a new potential role of P. lentiscus tissue extracts in human health care.

  13. Impact of different stages of juice processing on the anthocyanin, flavonol, and procyanidin contents of cranberries.

    PubMed

    White, Brittany L; Howard, Luke R; Prior, Ronald L

    2011-05-11

    Juice is the most common form in which cranberries are consumed; however there is limited information on the changes of polyphenolic content of the berries during juice processing. This study investigated the effects of three different pretreatments (grinding plus blanching; only grinding; only blanching) for cranberry juice processing on the concentrations of anthocyanins, flavonols, and procyanidins throughout processing. Flavonols and procyanidins were retained in the juice to a greater extent than anthocyanins, and pressing resulted in the most significant losses in polyphenolics due to removal of the seeds and skins. Flavonol aglycones were formed during processing as a result of heat treatment. Drying of cranberry pomace resulted in increased extraction of flavonols and procyanidin oligomers but lower extraction of polymeric procyanidins. The results indicate that cranberry polyphenolics are relatively stable during processing compared to other berries; however, more work is needed to determine their fate during storage of juices.

  14. Development of Marker-Free Transgenic Potato Tubers Enriched in Caffeoylquinic Acids and Flavonols.

    PubMed

    Li, Yang; Tang, Wenzhao; Chen, Jing; Jia, Ru; Ma, Lianjie; Wang, Shaoli; Wang, Jiao; Shen, Xiangling; Chu, Zhaohui; Zhu, Changxiang; Ding, Xinhua

    2016-04-13

    Potato (Solanum tuberosum L.) is a major crop worldwide that meets human economic and nutritional requirements. Potato has several advantages over other crops: easy to cultivate and store, cheap to consume, and rich in a variety of secondary metabolites. In this study, we generated three marker-free transgenic potato lines that expressed the Arabidopsis thaliana flavonol-specific transcriptional activator AtMYB12 driven by the tuber-specific promoter Patatin. Marker-free potato tubers displayed increased amounts of caffeoylquinic acids (CQAs) (3.35-fold increases on average) and flavonols (4.50-fold increase on average). Concentrations of these metabolites were associated with the enhanced expression of genes in the CQA and flavonol biosynthesis pathways. Accumulation of CQAs and flavonols resulted in 2-fold higher antioxidant capacity compared to wild-type potatoes. Tubers from these marker-free transgenic potatoes have therefore improved antioxidant properties.

  15. The Physiology of Protein S-acylation

    PubMed Central

    Chamberlain, Luke H.; Shipston, Michael J.

    2015-01-01

    Protein S-acylation, the only fully reversible posttranslational lipid modification of proteins, is emerging as a ubiquitous mechanism to control the properties and function of a diverse array of proteins and consequently physiological processes. S-acylation results from the enzymatic addition of long-chain lipids, most typically palmitate, onto intracellular cysteine residues of soluble and transmembrane proteins via a labile thioester linkage. Addition of lipid results in increases in protein hydrophobicity that can impact on protein structure, assembly, maturation, trafficking, and function. The recent explosion in global S-acylation (palmitoyl) proteomic profiling as a result of improved biochemical tools to assay S-acylation, in conjunction with the recent identification of enzymes that control protein S-acylation and de-acylation, has opened a new vista into the physiological function of S-acylation. This review introduces key features of S-acylation and tools to interrogate this process, and highlights the eclectic array of proteins regulated including membrane receptors, ion channels and transporters, enzymes and kinases, signaling adapters and chaperones, cell adhesion, and structural proteins. We highlight recent findings correlating disruption of S-acylation to pathophysiology and disease and discuss some of the major challenges and opportunities in this rapidly expanding field. PMID:25834228

  16. Two New Triterpene Glycosides from Centella asiatica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytochemical investigation of the leaves of Centella asiatica resulted in the isolation and characterization of one new ursane type triterpene glycoside; asiaticoside G along with nine known compounds, that were characterized as ursane type triterpenes and /or their glycoside; asiatic acid (2), mad...

  17. Neuroprotective actions of flavones and flavonols: mechanisms and relationship to flavonoid structural features.

    PubMed

    Dajas, Federico; Andrés, Abin-Carriquiry Juan; Florencia, Arredondo; Carolina, Echeverry; Felicia, Rivera-Megret

    2013-03-01

    Epidemiological studies have shown positive preventive action of flavonoids on cardiovascular and neurodegenerative events. Among the six groups in which flavonoids are classified, the flavones and flavonols, based on the backbone of 2-phenylchromen-4-one (2-phenyl-1-benzopyran-4-one) are the most commonly encountered within the families and genera of the higher plants. Numerous studies support a neuroprotective activity of flavones such as luteolin and flavonols such as kaempherol and quercetin in experimental focal ischemia and models of neurodegeneration. Antioxidation, modulation of signaling cascades and gene expression as well as anti-inflammation appear as the main protective mechanisms and mitochondria are a likely main target mediating the preventive actions against oxidative stress. Flavones and flavonols re-establish the redox regulation of proteins, transcription factors and signaling cascades that are otherwise inhibited by elevated oxidative stress. The final survival or death of the neuron depends on flavone and flavonol concentrations, time of exposure and, mainly, metabolic and oxidative neuronal circumstances. Neuroprotection appears to be linked to specific structural motifs, beyond those involved in antioxidation. By themselves or as templates for synthetic compounds, flavone and flavonol molecules show potential as multi-targeted therapeutic tools for protecting the brain. Nonetheless, more research needs to be done on the correlation of potential beneficial effects of flavones and flavonols and their mechanisms of action.

  18. Cloning and regulation of flavonol 3-sulfotransferase in cell-suspension cultures of Flaveria bidentis.

    PubMed Central

    Ananvoranich, S; Varin, L; Gulick, P; Ibrahim, R

    1994-01-01

    Flaveria spp. accumulate flavonol sulfate esters whose biosynthesis is catalyzed by a number of position-specific flavonol sulfotransferases. Although the accumulation of sulfated flavonols appears to be tissue specific and developmentally regulated and to vary among related species, little is known about the mechanism of regulation controlling the synthesis of these metabolites. In the present work, we report the isolation of a cDNA clone from Flaveria bidentis (pBFST3) encoding flavonol 3-sulfotransferase (F3-ST), which catalyzes the first step in the biosynthesis of flavonol polysulfates. This clone (pBFST3) was expressed in Escherichia coli and produced an F3-ST with high affinity for the flavonol aglycones, quercetin, and its 7-methyl derivative, rhamnetin. In addition, the synthetic auxin 2,4-dichlorophenoxyacetic acid was shown to induce F3-ST enzyme activity and F3-ST mRNA transcript levels in cell cultures of F. bidentis. The F3-ST mRNA levels increased within the first 3 h, reaching a maximum after 24 h of treatment, and remained elevated for up to 48 h. Treatments with either quercetin 3-sulfate or quercetin 3,7,4'-trisulfate reduced F3-ST enzyme activity in cell cultures but had no effect on the transcript levels. These results are discussed in relation to the putative role of flavonoid conjugates in the regulation of auxin transport. PMID:7991681

  19. Involvement of P-glycoprotein in regulating cellular levels of Ginkgo flavonols: quercetin, kaempferol, and isorhamnetin.

    PubMed

    Wang, Yi; Cao, Jiang; Zeng, Su

    2005-06-01

    Quercetin, kaempferol, and isorhamnetin were the most important flavonoid constituents in extracts from Ginkgo biloba leaves. Transport studies of Ginkgo flavonols were performed in Caco-2 cell mono-layers. Their apparent permeability in absorptive and secretion directions was determined, and quercetin, kaempferol and isorhamnetin displayed polarized transport, with the Papp,B-A being higher than the Papp,A-B (P<0.01 for quercetin, P<0.001 for kaempferol and isorhamnetin, Student's t-test). Bcap37/MDR1 cells, which were transfected with a P-glycoprotein (P-gp) gene construct, were treated with quercetin, kaempferol or isorhamnetin. The concentrations of Ginkgo flavonol in Bcap37/MDR1 cells were lower than those in parent cells (P<0.05 for quercetin, P<0.01 for isorhamnetin, Mann-Whitney U test). The concentrations of the flavonol in transfected cells increased when incubated with the P-gp inhibitor verapamil (P<0.05 for kaempferol, Mann-WhitneyU test). A colorometric assay for ATPase activity was applied to the detection of interaction of flavonol with P-gp. Quercetin and kaempferol inhibited the ATPase activity, and isorhamnetin stimulated the ATPase activity (P<0.05 for isorhamnetin, Mann Whitney U test). The results indicated that Ginkgo flavonols quercetin, kaempferol and isorhamnetin were substrates of P-gp. The P-gp type efflux pump might limit the bioavailability of Ginkgo flavonols.

  20. Modified acyl-ACP desaturase

    DOEpatents

    Cahoon, E.B.; Shanklin, J.; Lindgvist, Y.; Schneider, G.

    1998-01-06

    Disclosed is a method for modifying the chain length and double bond positional specificities of a soluble plant fatty acid desaturase. More specifically, the method involves modifying amino acid contact residues in the substrate binding channel of the soluble fatty acid desaturase which contact the fatty acid. Specifically disclosed is the modification of an acyl-ACP desaturase. Amino acid contact residues which lie within the substrate binding channel are identified, and subsequently replaced with different residues to effect the modification of activity. 1 fig.

  1. The Passiflora tripartita (Banana Passion) fruit: a source of bioactive flavonoid C-glycosides isolated by HSCCC and characterized by HPLC–DAD–ESI/MS/MS.

    PubMed

    Simirgiotis, Mario J; Schmeda-Hirschmann, Guillermo; Bórquez, Jorge; Kennelly, Edward J

    2013-01-28

    The banana passion fruit (Passiflora tripartita Breiter, Passifloraceae) known as "tumbo" is very appreciated in tropical and subtropical countries of South America. Methanolic extracts from peel and the fruit juice of P. tripartita growing in Chile were analyzed for antioxidant capacity as well as for flavonoid and phenolic content. A chromatographic method was developed for the rapid identification of the main phenolics in the samples by HPLC-DAD and HPLC-MS. The fast fingerprint analysis allowed the detection of eighteen flavonoid C-glycosides and four flavonoid O-glycoside derivatives which were characterized by UV spectra and ESI-MS-MS analysis. Several of the C-glycosides detected are structurally related to the orientin derivative 4'-methoxy-luteolin-8-C-(6"acetyl)-b-D-glucopyranoside (31), fully elucidated by spectroscopic methods. The antioxidant derivative 31 along with schaftoside, vicenin II, orientin and vitexin were isolated from the fruit extract by high-speed countercurrent chromatography (HSCCC). A suitable method for the preparative isolation of flavonol C-glycosides from "tumbo" extracts by HSCCC is reported. The pulp of the fruits showed good antioxidant capacity (12.89 ± 0.02 mg/mL in the DPPH assay). The peel presented the highest content of flavonoids (56.03 ± 4.34 mg quercetin/100 g dry weight) which is related to the highest antioxidant power (10.41 ± 0.01 mg/mL in the DPPH assay).

  2. Chelation behavior of various flavonols and transfer of flavonol-chelated zinc(II) to alanylaspartic dipeptide: A PCM/DFT investigation

    NASA Astrophysics Data System (ADS)

    Yasarawan, Nuttawisit; Thipyapong, Khajadpai; Ruangpornvisuti, Vithaya

    2016-03-01

    Alanylaspartic dipeptide (AlaAsp) and zinc(II)-flavonol complex could represent a metal-binding site in proteins and a metal-ion releasing agent, respectively. Chelation of zinc(II) by either AlaAsp or flavonol ligands in aqueous solution has been examined using DFT methods with polarizable continuum model (PCM/DFT). Coordination geometry, complexation stoichiometry, coordination bond strength, preferable metal-binding site on ligands and effect of water coordination on the stability of complexes have been addressed. In several cases, the long-range corrected density functional CAM-B3LYP allows the most accurate prediction of both structural and spectroscopic data. The preferential transfer of flavonol-chelated zinc(II) to AlaAsp under solvation is attainable through the ligand-exchange reaction. The energy barrier of such reaction is significantly dependent on the degree of hydrogen bonding within the transition state. In summary, either hydroxylation or methoxylation at particular positions on the 3-hydroxyflavone backbone significantly affects the reactivity of flavonol chelates in the metal-ion transfer.

  3. Triterpenoidal glycosides from Justicia betonica.

    PubMed

    Kanchanapoom, Tripetch; Noiarsa, Pawadee; Ruchirawat, Somsak; Kasai, Ryoji; Otsuka, Hideaki

    2004-09-01

    dFrom the aerial portion of Justicia betonica L., four triterpenoidal glycosides (justiciosides A-D) were isolated. Their structures were established through chemical and NMR spectroscopic analyses as olean-12-ene-1beta,3beta,11alpha,28-tetraol 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside, olean-12-ene-1beta,3beta,11alpha,28-tetraol 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside, 11alpha-methoxy-olean-12-ene-1beta,3beta,28-triol 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside, 11alpha-methoxy-olean-12-ene-1beta,3beta,28-triol 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside, respectively.

  4. HPLC-DAD-ESI/MS(n) profiling of phenolic compounds from Lathyrus cicera L. seeds.

    PubMed

    Ferreres, F; Magalhães, S C Q; Gil-Izquierdo, A; Valentão, P; Cabrita, A R J; Fonseca, A J M; Andrade, P B

    2017-01-01

    Lathyrus cicera L. seeds are of interest for food and feed purposes. Despite the recognized antioxidant activity of the seeds, arising from the phenolic fraction, their phenolic compounds have not been studied in depth yet. Therefore, to determine the phenolics profile of these seeds, a target analysis was performed using high-performance liquid chromatography coupled to photodiode-array detection and electrospray ionization/ion trap mass spectrometry (HPLC-DAD-ESI/MS(n)). Thirty-seven glycosylated flavonoids were identified for the first time in the seeds of this species and, according to their MS fragmentation, clustered in flavonol-3-O-di-/tri-glycosides-7-O-rhamnosides and other flavonol-glycosides, and flavonol-3-O-(cinnamoyl)glycoside-7-O-rhamnosides, flavonol-3-O-(dihydrophaseoyl, cinnamoyl)glycoside-7-O-rhamnosides and flavonol-3-O-(malonyl)glycoside-7-O-rhamnosides. Glycosides of kaempferol were the main flavonoids found (10 non-acylated and 21 acylated), followed by those of quercetin (3) and those of isorhamnetin, apigenin and luteolin (1). The most abundant flavonols were identified as kaempferol-3-O-(2-hexosyl)hexoside-7-O-rhamnosides. The methodology used allowed to increase the knowledge on a relevant phytochemical class of seeds from L. cicera.

  5. Glycosides from the root of Iodes cirrhosa.

    PubMed

    Gan, Maoluo; Zhang, Yanling; Lin, Sheng; Liu, Mingtao; Song, Weixia; Zi, Jiachen; Yang, Yongchun; Fan, Xiaona; Shi, Jiangong; Hu, Jinfeng; Sun, Jiandong; Chen, Naihong

    2008-04-01

    Seven new neolignan glycosides ( 1- 7), two arylglycerol glycosides ( 8, 9), and 18 known glycosides have been isolated from an ethanolic extract of the root of Iodes cirrhosa. Their structures including absolute configurations were determined by spectroscopic and chemical methods. Based on analysis of the NMR data of threo and erythro 8-4'-oxyneolignans and arylglycerols in different solvents, the validity of J 7,8 and Deltadelta C8-C7 values to distinguish threo and erythro derivatives was discussed. In the in vitro assays, compound 4 and liriodendrin ( 17) both showed activity against glutamate-induced PC12 cell damage at 10 (-5) M.

  6. Four new phenolic glycosides from Baoyuan decoction.

    PubMed

    Ma, Xiaoli; Guo, Xiaoyu; Zhao, Mingbo; Tu, Pengfei; Jiang, Yong

    2017-03-01

    Four new phenolic glycosides, including two flavonoid glycosides (1 and 2) and two lignan glycosides (3 and 4), were isolated from the traditional Chinese medicine formula, Baoyuan decoction. Their structures were established by detailed analysis of the NMR and HR-ESI-MS spectroscopic data and their absolute configurations were determined by the experimental electronic circular dichroism data as well as chemical methods. Furthermore, the sources of the four new compounds were determined by the UPLC-Qtrap-MS method, which proved that 1 and 2 are originated from Glycyrrhiza uralensis, and 3 and 4 are from Cinnamomum cassia.

  7. Approach to the study of flavone di-C-glycosides by high performance liquid chromatography-tandem ion trap mass spectrometry and its application to characterization of flavonoid composition in Viola yedoensis.

    PubMed

    Cao, Jie; Yin, Chengle; Qin, Yan; Cheng, Zhihong; Chen, Daofeng

    2014-10-01

    The mass spectrometric (MS) analysis of flavone di-C-glycosides has been a difficult task due to pure standards being unavailable commercially and to that the reported relative intensities of some diagnostic ions varied with MS instruments. In this study, five flavone di-C-glycoside standards from Viola yedoensis have been systematically studied by high performance liquid chromatography-electrospray ionization-tandem ion trap mass spectrometry (HPLC-ESI-IT-MS(n)) in the negative ion mode to analyze their fragmentation patterns. A new MS(2) and MS(3) hierarchical fragmentation for the identification of the sugar nature (hexoses or pentoses) at C-6 and C-8 is presented based on previously established rules of fragmentation. Here, for the first time, we report that the MS(2) and MS(3) structure-diagnostic fragments about the glycosylation types and positions are highly dependent on the configuration of the sugars at C-6 and C-8. The base peak ((0,2) X1 (0,2) X(2)(-) ion) in MS(3) spectra of di-C-glycosides could be used as a diagnostic ion for flavone aglycones. These newly proposed fragmentation behaviors have been successfully applied to the characterization of flavone di-C-glycosides found in V. yedoensis. A total of 35 flavonoid glycosides, including 1 flavone mono-C-hexoside, 2 flavone 6,8-di-C-hexosides, 11 flavone 6,8-di-C-pentosides, 13 flavone 6,8-C-hexosyl-C-pentosides, 5 acetylated flavone C-glycosides and 3 flavonol O-glycosides, were identified or tentatively identified on the base of their UV profiles, MS and MS(n) (n = 5) data, or by comparing with reference substances. Among these, the acetylated flavone C-glycosides were reported from V. yedoensis for the first time.

  8. Recent developments in β-C-glycosides: synthesis and applications.

    PubMed

    Lalitha, Krishnamoorthy; Muthusamy, Kumarasamy; Prasad, Y Siva; Vemula, Praveen Kumar; Nagarajan, Subbiah

    2015-01-30

    In the last few years, considerable progress has been made in the synthesis of C-glycosides. Despite its challenging chemistry, due to its versatility, C-glycosides play a pivotal role in developing novel materials, surfactants and bioactive molecules. In this review, we present snapshots of various synthetic methodologies developed for C-glycosides in the recent years and the potential application of C-glycosides derived from β-C-glycosidic ketones.

  9. A general synthetic strategy and the anti-proliferation properties on prostate cancer cell lines for natural phenylethanoid glycosides.

    PubMed

    Mulani, Shaheen K; Guh, Jih-Hwa; Mong, Kwok-Kong Tony

    2014-05-14

    A general strategy for the synthesis of phenylethanoid glycosides (PhG) including echinacoside 1, acteoside 2, calceolarioside-A 3 and calceolarioside-B 4 is reported. The strategy features the application of low substrate concentration glycosylation and N-formyl morpholine modulated glycosylation methods for the construction of 1,2-trans β- and α-glycosidic bonds. The reported strategy does not invoke the use of the participatory acyl protecting function, which is incompatible with the ester function present in target PhG compounds. A preliminary study of the anti-proliferation properties of the PhG compounds 1–4 was performed; the acteoside 2 exhibited the best inhibition on the prostatic cancer cell proliferation.

  10. Hepta-, hexa-, penta-, tetra-, and trisaccharide resin glycosides from three species of Ipomoea and their antiproliferative activity on two glioma cell lines.

    PubMed

    León-Rivera, Ismael; Del Río-Portilla, Federico; Enríquez, Raúl G; Rangel-López, Edgar; Villeda, Juana; Rios, María Yolanda; Navarrete-Vázquez, Gabriel; Hurtado-Días, Israel; Guzmán-Valdivieso, Ulises; Núñez-Urquiza, Verónica; Escobedo-Martínez, Carolina

    2017-03-01

    Six new partially acylated resin glycosides were isolated from convolvulin of Ipomoea purga, Ipomoea stans, and Ipomoea murucoides (Convolvulaceae). The structures of compounds 1-6 were elucidated by a combination of NMR spectroscopy and mass spectrometry. The structure of jalapinoside B (1) consists of a hexasaccharide core bonded to an 11-hydroxytetradecanoic (convolvulinic) acid forming a macrolactone acylated by a 2-methylbutanoyl, a 3-hydroxy-2-methylbutanoyl, and a quamoclinic acid B units. Purginoic acid A (2) contains a hexasaccharide core bonded to a convolvulinic acid acylated by a 3-hydroxy-2-methylbutanoyl unit. Stansin A (4) is an ester-type heterodimer, and consists of two stansoic acid A (3) units, acylated by 2-methylbutanoic and 3-hydroxy-2-methylbutanoic acids. The site of lactonization was located at C-3 of Rhamnose, and the position for the ester linkage of the monomeric unit B on the macrolactone unit A was established as C-4 of the terminal rhamnose. Compounds 5 and 6 are glycosidic acids. Murucinic acid II (5) is composed of a pentasaccharide core bonded to an 11-hydroxyhexadecanoic (jalapinolic) acid, acylated by an acetyl unit. Stansinic acid I (6) is a tetrasaccharide core bonded to a jalapinolic acid, acylated by 2-methylbutanoyl and 3-hydroxy-2-methylbutanoyl units. Preliminary testing showed the cytotoxicity of compounds 1-6 toward OVCAR and UISO-SQC-1 cancer cell lines. In addition, compound 1 showed an antiproliferative activity on glioma C6 and RG2 tumor cell lines. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Antiviral Effect of Methylated Flavonol Isorhamnetin against Influenza

    PubMed Central

    Dayem, Ahmed Abdal; Choi, Hye Yeon; Kim, Young Bong; Cho, Ssang-Goo

    2015-01-01

    Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3′, and 4′ positions of the 15-carbon flavonoid skeleton, and found that the strongest antiviral effect was induced by isorhamnetin. Similar to quercetin and kaempferol, isorhamnetin possesses a hydroxyl group on the C ring, but it has a 3′-methyl group on the B ring that is absent in quercetin and kaempferol. Co-treatment and pre-treatment with isorhamnetin produced a strong antiviral effect against the influenza virus A/PR/08/34(H1N1). However, isorhamnetin showed the most potent antiviral potency when administered after viral exposure (post-treatment method) in vitro. Isorhamnetin treatment reduced virus-induced ROS generation and blocked cytoplasmic lysosome acidification and the lipidation of microtubule associated protein1 light chain 3-B (LC3B). Oral administration of isorhamnetin in mice infected with the influenza A virus significantly decreased lung virus titer by 2 folds, increased the survival rate which ranged from 70–80%, and decreased body weight loss by 25%. In addition, isorhamnetin decreased the virus titer in ovo using embryonated chicken eggs. The structure-activity relationship (SAR) of isorhamnetin could explain its strong anti-influenza virus potency; the methyl group located on the B ring of isorhamnetin may contribute to its strong antiviral potency against influenza virus in comparison with other flavonoids. PMID:25806943

  12. Antiviral effect of methylated flavonol isorhamnetin against influenza.

    PubMed

    Abdal Dayem, Ahmed; Choi, Hye Yeon; Kim, Young Bong; Cho, Ssang-Goo

    2015-01-01

    Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3', and 4' positions of the 15-carbon flavonoid skeleton, and found that the strongest antiviral effect was induced by isorhamnetin. Similar to quercetin and kaempferol, isorhamnetin possesses a hydroxyl group on the C ring, but it has a 3'-methyl group on the B ring that is absent in quercetin and kaempferol. Co-treatment and pre-treatment with isorhamnetin produced a strong antiviral effect against the influenza virus A/PR/08/34(H1N1). However, isorhamnetin showed the most potent antiviral potency when administered after viral exposure (post-treatment method) in vitro. Isorhamnetin treatment reduced virus-induced ROS generation and blocked cytoplasmic lysosome acidification and the lipidation of microtubule associated protein1 light chain 3-B (LC3B). Oral administration of isorhamnetin in mice infected with the influenza A virus significantly decreased lung virus titer by 2 folds, increased the survival rate which ranged from 70-80%, and decreased body weight loss by 25%. In addition, isorhamnetin decreased the virus titer in ovo using embryonated chicken eggs. The structure-activity relationship (SAR) of isorhamnetin could explain its strong anti-influenza virus potency; the methyl group located on the B ring of isorhamnetin may contribute to its strong antiviral potency against influenza virus in comparison with other flavonoids.

  13. Stereoselective Synthesis of β-manno-Glycosides

    NASA Astrophysics Data System (ADS)

    Ishiwata, Akihiro; Ito, Yukishige

    Among the various types of O-glycosides with biological relevance, the β-glycoside of D-mannose (β-manno-glycoside) has been considered as one of the most challenging targets from a synthetic point of view. The majority of synthetic approaches to β-manno-glycoside can be put into two categories (the direct glycosylation and the glycosylation-inversion approaches). Additionally, a variety of intriguing approaches have been investigated with substantial success (alkylative glycosylation of 1,2-stannylene acetal, reductive manipulation of orthoester, intramolecular aglycon delivery, and enzymatic glycosylation). In this chapter, progress in the conceptually demanding β-mannosylation technology will be discussed, including current state of the art, with particular focus upon applications related to the synthesis of glycoprotein-related oligosaccharides.

  14. Two new coumarin glycosides from Peucedanum praeruptorum.

    PubMed

    Chang, Hai-Tao; Okada, Yoshihito; Ma, Ting-Jun; Okuyama, Toru; Tu, Peng-Fei

    2008-01-01

    Two new coumarin glycosides, praerosides VI (1) and VII (2), were isolated from the roots of Peucedanum praeruptorum Dunn. Their structures were elucidated by chemical reaction and NMR spectroscopic methods.

  15. Three new glycosides from Hylocereus undatus.

    PubMed

    Wu, Xin; Wang, Ying; Huang, Xiao-Jun; Fan, Chun-Lin; Wang, Guo-Cai; Zhang, Xiao-Qi; Zhang, Qin-Wen; Ye, Wen-Cai

    2011-08-01

    Three new glycosides, undatusides A-C (1-3), and 11 known compounds (4-14) were isolated from the flowers of Hylocereus undatus. Their structures were elucidated on the basis of spectroscopic data and chemical method.

  16. Solvent-free bismuth oxycarbonate-mediated mechanochemical glycosylation: A simple greener alternative to access O-/S-glycosides efficiently.

    PubMed

    Sethi, Kashmir Prasad; Kartha, K P Ravindranathan

    2016-11-03

    Preparation of a variety of per-O-acylated O- and S-glycosides of a set of commonly encountered mono- and disaccharides has been achieved effectively by solvent-free grinding of the corresponding acetylated/benzoylated glycosyl bromide and the desired acceptor alcohol/thiol in the presence of bismuth carbonate in a planetary ball mill. The method is simple, requires short reaction time periods and is practical allowing it to be performed at a milligram-to multi-gram scale as required. In the cases where the product is crystalline, it was often obtained in practically pure form by crystallization (and without the need for chromatographic isolation).

  17. Partial Purification and Characterization of Three Flavonol-Specific Sulfotransferases from Flaveria chloraefolia1

    PubMed Central

    Varin, Luc; Ibrahim, Ragai K.

    1989-01-01

    Three distinct flavonol-specific sulfotransferases were partially purified from the shoot tips of Flaveria chloraefolia A. Gray by fractional precipitation with ammonium sulfate, followed by gel filtration on Sephacryl S-200, 3′-phosphoadenosine 5-phosphate-Agarose affinity chromatography and chromatofocusing on Mono P. These enzymes exhibited expressed specificity for positions 3 of various flavonol acceptors and of 3′ and 4′ of flavonol 3-sulfate. The three sulfotransferases had similar molecular weights (35,000), exhibited no requirement for divalent cations and were not inhibited by SH group reagents. Their Km values for both the sulfate donor and the flavonol acceptors were of the same order of magnitude (ca. 0.2-0.4 micromolar). Except for the 3-sulfotransferase, which exhibited two optima at pH 6.5 and 8.5, the 3′ and the 4′-sulfotransferases had a pH optimum of 7.5. The three enzymes could be resolved only by chromatofocusing and were eluted at pH 5.4, pH 6.0, and pH 5.1 for the 3-, 3′- and 4′-sulfotransferases, respectively. The substrate specificity of these three enzymes is discussed in relation to the biosynthesis of polysulfated flavonols in F. chloraefolia. PMID:16666908

  18. Anthocyanins and flavonols are responsible for purple color of Lablab purpureus (L.) sweet pods.

    PubMed

    Cui, Baolu; Hu, Zongli; Zhang, Yanjie; Hu, Jingtao; Yin, Wencheng; Feng, Ye; Xie, Qiaoli; Chen, Guoping

    2016-06-01

    Lablab pods, as dietary vegetable, have high nutritional values similar to most of edible legumes. Moreover, our studies confirmed that purple lablab pods contain the natural pigments of anthocyanins and flavonols. Compared to green pods, five kinds of anthocyanins (malvidin, delphinidin and petunidin derivatives) were found in purple pods by HPLC-ESI-MS/MS and the major contents were delphinidin derivatives. Besides, nine kinds of polyphenol derivatives (quercetin, myricetin, kaempferol and apigenin derivatives) were detected by UPLC-ESI-MS/MS and the major components were quercetin and myricetin derivatives. In order to discover their molecular mechanism, expression patterns of biosynthesis and regulatory gens of anthocyanins and flavonols were investigated. Experimental results showed that LpPAL, LpF3H, LpF3'H, LpDFR, LpANS and LpPAP1 expressions were significantly induced in purple pods compared to green ones. Meanwhile, transcripts of LpFLS were more abundant in purple pods than green or yellow ones, suggestind that co-pigments of anthocyanins and flavonols are accumulated in purple pods. Under continuously dark condition, no anthocyanin accumulation was detected in purple pods and transcripts of LpCHS, LpANS, LpFLS and LpPAP1 were remarkably repressed, indicating that anthocyanins and flavonols biosynthesis in purple pods was regulated in light-dependent manner. These results indicate that co-pigments of anthocyanins and flavonols contribute to purple pigmentations of pods.

  19. Triterpenoid glycosides from Ladenbergia hexandra Klotzsch.

    PubMed

    Furukawa, Megumi; Kamo, Satoshi; Makino, Mitsuko; Kurita, Masahiro; Tabata, Keiichi; Matsuzaki, Keiichi; Suzuki, Takashi; Uchiyama, Taketo

    2017-04-01

    From the bark of Ladenbergia hexandra Klotzsch, ten triterpenoid glycosides were isolated along with five known compounds, and their structures were determined based on extensive NMR and mass spectroscopic, GC and HPLC analyses. Some triterpenoid glycosides contained 6-deoxy-D-allose or D-allose as a sugar moiety. The absolute stereochemical assignment of the sugars was determined by comparison with synthetic samples, as well as by GC and HPLC analysis.

  20. Pregnane glycosides from Caralluma adscendens var. fimbriata.

    PubMed

    Kunert, Olaf; Rao, Vijayalakshmi Gurunath; Babu, Gummadi Sridhar; Sujatha, Palatheeya; Sivagamy, Malayalam; Anuradha, Sandala; Rao, Belvotagi Venkatrao Adavi; Kumar, Bobbala Ravi; Alex, Robert Michael; Schühly, Wolfgang; Kühnelt, Doris; Rao, Ghanakota Venkateshwara; Rao, Achanta Venkata Narasimha Appa

    2008-02-01

    Eleven novel pregnane glycosides, 2-7 and 9-13, of which four, i.e., 10-13, comprised a new pregnane-type genin exhibiting a hydroxymethylene instead of a Me group at C(19), and the known pregnane glycoside stalagmoside V (8) were isolated from whole plants of Caralluma adscendens var. fimbriata, a native Indian succulent plant. Their structures were elucidated by extensive 2D-NMR spectroscopic studies.

  1. New pregnane glycosides from Caralluma dalzielii.

    PubMed

    De Leo, Marinella; De Tommasi, Nunziatina; Sanogo, Rokia; Autore, Giuseppina; Marzocco, Stefania; Pizza, Cosimo; Morelli, Ivano; Braca, Alessandra

    2005-08-01

    Twenty-seven new pregnane glycosides were isolated from the whole plant of Caralluma dalzielii, and their structures elucidated from extensive 2D NMR analysis as well as ESI-MS experiments. All isolated compounds were tested for their antiproliferative activity on J774.A1, HEK-293, and WEHI-164 cell lines. Moderate to high potency of cytotoxicities were found in almost all tested compounds, confirming the significant cytotoxic activity of pregnane glycosides.

  2. Characterization of flavonoid glycosides from fenugreek (Trigonella foenum-graecum) crude seeds by HPLC-DAD-ESI/MS analysis.

    PubMed

    Benayad, Zakia; Gómez-Cordovés, Carmen; Es-Safi, Nour Eddine

    2014-11-11

    Fenugreek (Trigonella foenum-graecum) is a medicinal plant which is widely used for its pharmacological properties. In this study the phenolic composition of fenugreek crude seeds originating from Morocco has been investigated. Extraction was performed from defatted seeds by a hydromethanolic solution using an Accelerated Solvent Extractor. HPLC technique coupled to negative ion electrospray ionization mass spectrometry and diode array detection was employed to identify the polyphenol in the obtained extract. The obtained results allowed the detection of 32 phenolic compounds among which various flavonoid glycosides and phenolic acids have been tentatively identified on the basis of their UV and MS spectra, and comparisons with standards when available, as well as with literature data. A systematic study of the obtained MS spectra and the observed fragmentation showed that most of the identified compounds were acylated and non-acylated flavonoids with apigenin, luteolin and kaempferol as aglycons. Hydroxycinnamic acids mostly dominated by caffeic acid derivatives were also detected. The quantitative analysis of the identified compounds showed that the phenolic composition of the studied crude fenugreek seeds was predominantly acylated and non-acylated flavone derivatives with apigenin as the main aglycon.

  3. Apple flavonols and n-3 polyunsaturated fatty acid-rich fish oil lowers blood C-reactive protein in rats with hypercholesterolemia and acute inflammation.

    PubMed

    Sekhon-Loodu, Satvir; Catalli, Adriana; Kulka, Marianna; Wang, Yanwen; Shahidi, Fereidoon; Rupasinghe, H P Vasantha

    2014-06-01

    Both quercetin glycosides and omega-3 polyunsaturated fatty acids (n-3 PUFA) are well established for their individual health benefits in ameliorating metabolic disease. However, their combined effects are not well documented. It was hypothesized that the beneficial properties of quercetin glycosides can be enhanced when provided in combination with n-3 PUFA. Therefore, the aim of the present study was to investigate the effects of apple flavonols (AF) and fish oil (FO), alone and in combination, on proinflammatory biomarkers and lipid profiles in rats fed a high-fat diet. Sixty male Wistar rats were randomly divided into 5 groups (n = 12) and fed a high-fat diet for 4 weeks. One of the 5 groups of rats was used as the high-fat control. The other 4 groups of rats were injected with lipopolysaccharide (LPS) (5 mg/kg body weight) intraperitoneally, 5 hours before euthanization. One of these 4 groups was used as the hypercholerolemic and inflammatory control (high-fat with lipopolysaccharide [HFL]), and the other 3 received AF (HFL + 25 mg/kg per day AF), FO (HFL + 1 g/kg per day FO), or the combination (HFL + AF + FO). Compared to the HFL group, the AF, FO, and AF + FO groups showed lower serum concentrations of interleukin-6 and C-reactive protein (CRP) levels. The AF, FO, and AF + FO also had lowered serum triacylglycerol and non-high-density lipoprotein cholesterol (HDL-C) concentrations, but higher HDL-C levels relative to the HFL group. An additive effect was observed on serum CRP in the AF + FO group as compared with the AF or FO groups. The results demonstrated that AF and FO inhibited the production of proinflammatory mediators and showed an improved efficacy to lower serum CRP when administered in combination, and they significantly improved blood lipid profiles in rats with diet-induced hyperlipidemia and LPS-induced acute inflammation.

  4. Biosynthesis of plant-specific flavones and flavonols in Streptomyces venezuelae.

    PubMed

    Park, Sung Ryeol; Paik, Ji Hye; Ahn, Mi Sun; Park, Je Won; Yoon, Yeo Joon

    2010-09-01

    Recently, recombinant Streptomyces venezuelae has been established as a heterologous host for microbial production of flavanones and stilbenes, a class of plant-specific polyketides. In the present work, we expanded the applicability of the S. venezuelae system to the production of more diverse plant polyketides including flavones and flavonols. A plasmid with the synthetic codon-optimized flavone synthase I gene from Petroselium crispum was introduced to S. venezuelae DHS2001 bearing a deletion of the native pikromycin polyketide synthase gene, and the resulting strain generated flavones from exogenously fed flavanones. In addition, a recombinant S. venezuelae mutant expressing a codon-optimized flavanone 3beta-hydroxylase gene from Citrus siensis and a flavonol synthase gene from Citrus unshius also successfully produced flavonols.

  5. Hydroxycinnamic acids and flavonols in native edible berries of South Patagonia.

    PubMed

    Ruiz, Antonieta; Bustamante, Luis; Vergara, Carola; von Baer, Dietrich; Hermosín-Gutiérrez, Isidro; Obando, Luis; Mardones, Claudia

    2015-01-15

    Diverse edible berries are native to the Patagonian region of Southern Chile. These berries are underused because their nutritional properties are relatively unknown. In this work, the profiles and concentrations of hydroxycinnamic acid derivatives and flavonols, and the antioxidant capacity of the berry extracts, were studied using HPLC-DAD-ESI-MS/MS and CUPRAC assays, respectively. In total, 46 compounds were identified, including 17 hydroxycinnamic acid derivatives and 26 flavonols. Caffeoylquinic acid isomers were the most abundant compounds, and quercetin and myricetin derivatives were the main flavonols found. The berries from Ribes genera showed a high diversity and concentration of these 2 families of compounds and contained 3-caffeoylquinic acid and quercetin-3-rutinoside at the highest concentrations. The Patagonian berries, especially the berries of Rubus and Ribes genera, had high cupric reducing antioxidant capacity, comparable with that described for berries from the Northern hemisphere. These results contribute to promote the nutritional study of these fruits.

  6. Flavonols Stimulate Development, Germination, and Tube Growth of Tobacco Pollen 1

    PubMed Central

    Ylstra, Bauke; Touraev, Alisher; Moreno, Rosa Maria Benito; Stöger, Eva; van Tunen, Arjen J.; Vicente, Oscar; Mol, Joseph N. M.; Heberle-Bors, Erwin

    1992-01-01

    The effect of anther-derived substances on pollen function was studied using pollen produced by in vitro culture of immature pollen of tobacco (Nicotiana tabacum L.) and petunia (Petunia hybrida). Addition of conditioned medium consisting of diffusates from in situ matured pollen strongly increased pollen germination frequency and pollen tube growth, as well as seed set after in situ pollination. Thin-layer chromatography and depletion of phenolic substances by Dowex treatment indicated that flavonols are present in the diffusate and may be the active compounds. When added to the germination medium, flavonols (quercetin, kaempferol, myricetin) but not other flavonoids strongly promoted pollen germination frequency and pollen tube growth in vitro. The best results were obtained at very low concentrations of the flavonols (0.15-1.5 μm), indicating a signaling function. The same compounds were also effective when added during pollen development in vitro. Images Figure 1 Figure 5 PMID:16653074

  7. Acyl hydrolases from trans-AT polyketide synthases target acetyl units on acyl carrier proteins.

    PubMed

    Jenner, Matthew; Afonso, Jose P; Kohlhaas, Christoph; Karbaum, Petra; Frank, Sarah; Piel, Jörn; Oldham, Neil J

    2016-04-18

    Acyl hydrolase (AH) domains are a common feature of trans-AT PKSs. They have been hypothesised to perform a proofreading function by removing acyl chains from stalled sites. This study determines the substrate tolerance of the AH PedC for a range of acyl-ACPs. Clear preference towards short, linear acyl-ACPs is shown, with acetyl-ACP the best substrate. These results imply a more targeted housekeeping role for PedC: namely the removal of unwanted acetyl groups from ACP domains caused by erroneous transfer of acetyl-CoA, or possibly by decarboxylation of malonyl-ACP.

  8. Characterization of a citrus R2R3-MYB transcription factor that regulates the flavonol and hydroxycinnamic acid biosynthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavonols and hydroxycinnamic acids are important phenylpropanoid metabolites in plants. In this study, we isolated and characterized a citrus R2R3-MYB transcription factor CsMYBF1, encoding a protein belonging to the flavonol-specific MYB subgroup. Ectopic expression of CsMYBF1 in tomato led to an ...

  9. Fatty acyl-CoA reductase

    SciTech Connect

    Reiser, Steven E.; Somerville, Chris R.

    1998-12-01

    The present invention relates to bacterial enzymes, in particular to an acyl-CoA reductase and a gene encoding an acyl-CoA reductase, the amino acid and nucleic acid sequences corresponding to the reductase polypeptide and gene, respectively, and to methods of obtaining such enzymes, amino acid sequences and nucleic acid sequences. The invention also relates to the use of such sequences to provide transgenic host cells capable of producing fatty alcohols and fatty aldehydes.

  10. Steroidal glycosides from the leaves of Cestrum nocturnum.

    PubMed

    Mimaki, Yoshihiro; Watanabe, Kazuki; Sakagami, Hiroshi; Sashida, Yutaka

    2002-12-01

    Further phytochemical analysis aimed at the steroidal glycoside constituents of the leaves of Cestrum nocturnum has resulted in the isolation of eight new steroidal glycosides (1-8), which were classified into a spirostanol saponin (1), a furostanol saponin (2), a pseudo-furostanol saponin (3), two pregnane glycosides (4, 5), two cholestane glycosides (6, 7), and pregnane-carboxylic acid gamma-lactone glycoside (8), and of two known spirostanol glycosides (9, 10). The structures of the new compounds were elucidated on the basis of chemical and spectroscopic evidence.

  11. Ultraviolet-B radiation and water deficit interact to alter flavonol and anthocyanin profiles in grapevine berries through transcriptomic regulation.

    PubMed

    Martínez-Lüscher, Johann; Sánchez-Díaz, Manuel; Delrot, Serge; Aguirreolea, Jone; Pascual, Inmaculada; Gomès, Eric

    2014-11-01

    UV-B radiation and water deficit may trigger flavonol and anthocyanin biosynthesis in plant tissues. In addition, previous research has showed strong qualitative effects on grape berry skin flavonol and anthocyanin profiles in response to UV-B and water deficit. The aim of this study is to identify the mechanisms leading to quantitative and qualitative changes in flavonol and anthocyanin profiles, in response to separate and combined UV-B and water deficit. Grapevines (Vitis vinifera L. cv. Tempranillo) were exposed to three levels of UV-B radiation (0, 5.98 and 9.66 kJ m(-2) day(-1)) and subjected to two water regimes. A strong effect of UV-B on flavonol and anthocyanin biosynthesis was found, resulting in an increased anthocyanin concentration and a change in their profile. Concomitantly, two key biosynthetic genes (FLS1 and UFGT) were up-regulated by UV-B, leading to increased flavonol and anthocyanin skin concentration. Changes in flavonol and anthocyanin composition were explained to a large extend by transcript levels of F3'H, F3'5'H and OMT2. A significant interaction between UV-B and water deficit was found in the relative abundance of 3'4' and 3'4'5' substituted flavonols, but not in their anthocyanin homologues. The ratio between 3'4'5' and 3'4' substituted flavonols was linearly related to the ratios of F3'5'H and FLS1 transcription, two steps up-regulated independently by water deficit and UV-B radiation, respectively. Our results indicate that changes in flavonol profiles in response to environmental conditions are not only a consequence of changes in the expression of flavonoid hydroxylases; but also the result of the competition of FLS, F3'5'H and F3'H enzymes for the same flavonol substrates.

  12. Diterpene glycosides from Stevia phlebophylla A. Gray.

    PubMed

    Ceunen, Stijn; Wim, De Borggraeve; Compernolle, Frans; Mai, Anh Hung; Geuns, Jan M C

    2013-09-20

    The rare Mexican species Stevia phlebophylla A. Gray was long considered to be the only known Stevia species, beside the well-known S. rebaudiana, containing the highly sweet diterpenoid steviol glycosides. We report a re-evaluation of this claim after phytochemically screening leaves obtained from two herbarium specimens of S. phlebophylla for the presence of steviol glycosides. Despite extensive MS analyses, no steviol glycosides could be unambiguously verified. Instead, the main chromatographic peak eluting at retention times similar to those of steviol glycosides was identified as a new compound, namely 16β-hydroxy-17-acetoxy-ent-kauran-19-oic acid-(6-O-β-D-xylopyranosyl-β-D-glucopyranosyl) ester (1) on the basis of extensive NMR and MS data as well as the characterization of its acid hydrolysate. Seven more compounds were detected by ESIMS which are possibly structurally related to 1. It can therefore be concluded that S. phlebophylla is unlikely to contain significant amounts of steviol glycosides, if any.

  13. Sterol glycosides and cerebrosides accumulate in Pichia pastoris, Rhynchosporium secalis and other fungi under normal conditions or under heat shock and ethanol stress.

    PubMed

    Sakaki, T; Zähringer, U; Warnecke, D C; Fahl, A; Knogge, W; Heinz, E

    2001-06-01

    The occurrence of glycolipids such as sterol glycosides, acylated sterol glycosides, cerebrosides and glycosyldiacylglycerols was examined in the three yeast species Candida albicans, Pichia pastoris and Pichia anomala, as well as in the six fungal species Sordaria macrospora, Pyrenophora teres, Ustilago maydis, Acremonium chrysogenum, Penicillium olsonii and Rhynchosporium secalis. Cerebroside was found in all organisms tested, whereas acylated sterol glycosides and glycosyldiacylglycerols were not found in any organism. Sterol glycosides were detected in P. pastoris strain GS115, U. maydis, S. macrospora and R. secalis. This glycolipid occurred in both yeast and filamentous forms of U. maydis but in neither form of C. albicans. This suggests that sterol glycoside is not correlated with the separately grown dimorphic forms of these organisms. Cerebrosides and sterol glycosides from P. pastoris and R. secalis were purified and characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. The cerebrosides are beta-glucosyl ceramides consisting of a saturated alpha-hydroxy or non-hydroxy fatty acid and a Delta4,8-diunsaturated, C9-methyl-branched sphingobase. Sterol glycoside from P. pastoris was identified as ergosterol-beta-D-glucopyranoside, whereas the sterol glucosides from R. secalis contain two derivatives of ergosterol. The biosynthesis of sterol glucoside in P. pastoris CBS7435 and GS115 depended on the culture conditions. The amount of sterol glucoside in cells grown in complete medium was much lower than in cells from minimal medium and a strong increase in the content of sterol glucoside was observed when cells were subjected to stress conditions such as heat shock or increased ethanol concentrations. From these data we suggest that, in addition to Saccharomyces cerevisiae, new yeast and fungal model organisms should be used to study the physiological functions of glycolipids in eukaryotic cells. This suggestion is based on the

  14. New triterpenoid glycosides from the roots of Ilex asprella.

    PubMed

    Wang, Lei; Cai, Yan; Zhang, Xiao-Qi; Fan, Chun-Lin; Zhang, Qing-Wen; Lai, Xiao-Ping; Ye, Wen-Cai

    2012-02-15

    Eight new triterpenoid glycosides, named ilexasosides A-H, were isolated from the roots of Ilex asprella. Their structures were elucidated by spectroscopic and chemical analyses. Ilexasosides B and D are rare sulfated derivatives of ursane-type triterpenoid glycosides.

  15. Iridoid and megastigmane glycosides from Phlomis aurea.

    PubMed

    Kamel, M S; Mohamed, K M; Hassanean, H A; Ohtani, K; Kasai, R; Yamasaki, K

    2000-10-01

    From the leaves of Phlomis aurea, two new iridoids of unique structures named 3-epiphlomurin (1) and phlomurin (2), a new megastigmane glucoside phlomuroside (3) and a new benzyl alcohol glycoside having the structure benzyl alcohol-O-beta-xylopyranosyl-(1-->2)-beta-glucopyranoside (4) have been isolated together with four known iridoids auroside, lamiide, 8-epiloganin and ipolamiide, two known phenolic glycosides acteoside (verbascoside) and syringin, one known phenylethanoid glycoside 2-phenylethyl-O-beta-xylopyranosyl-(1-->2)-beta-glucopyranoside, one known lignan liriodendrin and three known flavonoids chrysoeriol-7-O-beta-glucopyranoside, acacetin-7-O-beta-glucopyranoside and luteolin-7-O-beta-glucopyranoside. The structures of the isolated compounds were verified by means of mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectral analyses.

  16. Bioactive spirostane glycosides from Tacca plantaginea.

    PubMed

    Liu, Zhen-Hua; Yan, Huan; Si, Yong-Ai; Ni, Wei; Chen, Yu; He, Li; Liu, Hai-Yang

    2016-02-01

    Eight new spirostane glycosides, taccaosides E-L (2-7, 11, and 14), along with 7 known spirostane glycosides were isolated from the extract of the whole plants of Tacca plantaginea (Hance) Drenth. Their structures were established on the basis of physical data, spectroscopic analysis (MS, 1D and 2D NMR), and chemical methods. The cytotoxicities of the isolates were evaluated in vitro against two human cancer cell lines (HEK293 and HepG2). The results showed that compound 1 had the strongest cytotoxic activity with IC50 values of 1.7 μM and 1.2 μM against the two cancer cell lines, respectively. Furthermore, the spirostane glycosides with 17α-hydroxyl group at their aglycones (10, 12, and 15) were tested for the induced platelet aggregation activity.

  17. Steviol glycosides: chemical diversity, metabolism, and function.

    PubMed

    Ceunen, Stijn; Geuns, Jan M C

    2013-06-28

    Steviol glycosides are a group of highly sweet diterpene glycosides discovered in only a few plant species, most notably the Paraguayan shrub Stevia rebaudiana. During the past few decades, the nutritional and pharmacological benefits of these secondary metabolites have become increasingly apparent. While these properties are now widely recognized, many aspects related to their in vivo biochemistry and metabolism and their relationship to the overall plant physiology of S. rebaudiana are not yet understood. Furthermore, the large size of the steviol glycoside pool commonly found within S. rebaudiana leaves implies a significant metabolic investment and poses questions regarding the benefits S. rebaudiana might gain from their accumulation. The current review intends to thoroughly discuss the available knowledge on these issues.

  18. New kaurene diterpenoid glycosides from fenugreek seeds.

    PubMed

    Pang, Xu; Kang, Li-Ping; Yu, He-Shui; Zhao, Yang; Xiong, Cheng-Qi; Zhang, Jie; Ma, Bai-Ping

    2013-01-01

    Two new kaurene diterpenoid glycosides, named Graecumoside A (1) and B (2), were isolated from fenugreek seeds, along with three known flavonoid-C-glycosides, isoorientin (3), isovitexin (4) and vitexin (5). By combined analyses of 1D- and 2D-NMR, and MS spectroscopy, the structures of two new compounds were elucidated as 3-O-β- D-glucopyranosyl kaur-5, 16-dien-3β, 6, 13β-trihydroxy-7-oxo-18-oic acid methyl ester and 3-O-β-neohesperidosyl kaur-5, 16-dien-3β, 6, 13β-trihydroxy-7-oxo-18-oic acid methyl ester, respectively. The kaurene diterpenoid glycosides were first isolated and identified from fenugreek seeds.

  19. Concordance between antioxidant activities and flavonol contents in different extracts and fractions of Cuscuta chinensis.

    PubMed

    Yen, Feng-Lin; Wu, Tzu-Hui; Lin, Liang-Tzung; Cham, Thau-Ming; Lin, Chun-Ching

    2008-05-15

    Chinese herbs employed in traditional Chinese medicine (TCM) have been used for centuries in the practice of medicated diet and dietetic therapy. The seed of Cuscuta chinensis Lam. (Convolvulaceae), a commonly used traditional Chinese herb, is frequently added in Chinese cooking and preparation of refreshments, including porridge and alcoholic beverages, to nourish the human body. In the present study, we compared the antioxidant activities of water and ethanol extracts from the seeds C. chinensis and also of its different organic fractions, including n-hexane, ethyl acetate, n-butanol and organic water, by assessing their DPPH (1,1-diphenyl-2-picryl hydrazine) free radical-scavenging, superoxide anion scavenging, anti-superoxide anion formation and anti-lipid peroxidation abilities. The flavonol contents of all test samples were analyzed by high-performance liquid chromatography with an ultraviolet (HPLC-UV) detector. The results showed that there is a direct correlation of the flavonol content with the antioxidant activities from the extracts and fractions of C. chinensis. Moreover, the ethyl acetate fraction demonstrated significantly better and higher antioxidant effects, and also had a higher flavonol content than had the remaining samples (P<0.05). The water fractions, however, exhibited the weakest antioxidant activity, and had low concentrations of flavonols. Thus, we suggest that the ethanol extract of C. chinensis, but not its water extract, could be used as a dietary nutritional supplement to promote human health and prevent oxidation-related diseases, due to its antioxidant properties.

  20. Fatty acid, flavonol, and mineral composition variability among seven macrotyloma uniflorum (Lam.) verdc. accessions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Horse gram [Macrotyloma uniflorum (Lam.) Verdc.] seeds containing high concentrations of fatty acids, flavonols and minerals will provide government, public and private organizations with a nutritious and healthy food for use by malnourished and food deprived people worldwide. Seeds from seven horse...

  1. A new acylated anthocyanin from the red flowers of Camellia hongkongensis and characterization of anthocyanins in the section Camellia species.

    PubMed

    Li, Jian-Bin; Hashimoto, Fumio; Shimizu, Keiichi; Sakata, Yusuke

    2009-06-01

    Twelve anthocyanins (1-12) were isolated from the red flowers of Camellia hongkongensis Seem. by chromatography using open columns. Their structures were elucidated on the basis of spectroscopic analyses, that is, proton-nuclear magnetic resonance, carbon 13-nuclear magnetic resonance, heteronuclear multiple quantum correlation, heteronuclear multiple bond correlation, high resolution electrospray ionization mass and ultraviolet visible spectroscopies. Out of these anthocyanins, a novel acylated anthocyanin, cyanidin 3-O-(6-O-(Z)-p-coumaroyl)-beta-galactopyranoside (6), two known acylated anthocyanins, cyanidin 3-O-(6-O-(E)-p-coumaroyl)-beta-galactopyranoside (7) and cyanidin 3-O-(6-O-(E)-caffeoyl)-beta-galactopyranoside (8), and three known delphinidin glycosides (10-12) were for the first time isolated from the genus Camellia. Furthermore, pigment components in C. japonica L., C. chekiangoleosa Hu and C. semiserrata Chi were studied. The results indicated that the distribution of anthocyanins was differed among these species. Delphinidin glycoside was only detected in the flowers of C. hongkongensis, which is a special and important species in the section Camellia. Based on the characterization of anthocyanins in the section Camellia species, there is a close relationship among these species, and C. hongkongensis might be an important parent for creating new cultivars with bluish flower color.

  2. Cytotoxic phenylpropanoid glycosides from Cirsium japonicum.

    PubMed

    Shang, Dong-Li; Ma, Qin-Ge; Wei, Rong-Rui

    2016-12-01

    Three new phenylpropanoid glycosides 1-3, along with nine known phenylpropanoid glycosides 4-12, were isolated from the aerial parts of Cirsium japonicum. The structures of isolated compounds were elucidated by chemical and spectroscopic methods. Compounds 1, 3, 6, 8, and 11 showed moderate cytotoxicities against MCF-7, U87, HCT116, and A549 cell lines with IC50 values in the range of 1.35-11.32 μM. The known compounds 4-12 were obtained from this plant for the first time.

  3. Polyoxypregnane glycosides from Caralluma retrospiciens.

    PubMed

    Halaweish, Fathi T; Huntimer, Eric; Khalil, Ashaf T

    2004-01-01

    Six related polyoxypregnane glycosides were isolated and characterised from Caralluma retrospiciens leaves. The compounds were identified as 12beta-benzoyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[3-O-methyl-6-deoxy-beta-D-allopyranosyl-(1 --> 4)-beta-D-cymaropyranosyl-(1 --> 4)-]-beta-D-cymaropyranoside], 12beta-benzoyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-allopyranosyl-(1 --> 4)-beta-D-cymaropyranosyl-(1 --> 4)-beta-D-cymaropyranoside], 12beta-benzoyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranoside], 12beta-benzoyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranoside], 12beta-benzoyloxy-11alpha-isovaleroyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranoside], and 12beta-benzoyloxy-11alpha-isovaleroyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl (1 --> 4)-3-O-methyl-6-deoxy-beta-D-allopyranosyl-(1 --> 4)-beta-D-cymaropyranosyl-(1 --> 4)-beta-D-cymaropyranoside]. The structures were determined by detailed analysis of one- and two-dimensional NMR spectra as well as by chemical means. The compounds showed cytotoxic activities towards brine shrimp having IC50 values of 1.19 x 10(-4), 8.83 x 10(-5), 2.64 x 10(-4), 2.26 x 10(-4), 2.39 x 10(-4) and 1.70 x 10(-4) M, respectively. This is the first report of the isolation of these compounds from a natural source.

  4. Regioselective Glucuronidation of Flavonols by Six Human UGT1A Isoforms

    PubMed Central

    Wu, Baojian; Hu, Ming

    2012-01-01

    Purpose Flavonols, a class of polyphenols, show a variety of biological activities such as antioxidant and anticancer. However, rapid in vivo O-glucuronidation posed a challenge to develop them as therapeutic agents. The objective of this paper is to determine the regioselective glucuronidation of flavonols by UGT1A isoforms (i.e., UGT1A1, UGT1A3, UGT1A7, UGT1A8, UGT1A9 and UGT1A10). Methods The kinetics of UGT1A1-, 1A3- and 1A7~1A10-mediated metabolisms of four flavonols that contain 7-OH group were characterized and kinetic parameters (Km, Vmax and intrinsic clearance (CLint=Vmax/Km)) were determined. Results UGT1A1 and 1A3 regioselectively metabolized 7-OH, whereas UGT1A7~1A10 preferred to glucuronidate 3-OH group. UGT1A1 and UGT1A9 were the most efficient conjugating enzymes with Km of ≤1 µM and Vmax/Km of >3 ml/min/mg protein, resulting in a CLint value as high as 6 ml/min/mg protein. Additionally, the four flavonols generally strongly self-inhibited the UGT1A1-mediated glucuronidation, with Ks (substrate inhibition constant) of ≤ 5.4 µM. Conclusion UGT1A isoforms displayed distinct positional preferences between 3-OH and 7-OH in the glucuronidation of flavonols. The differentiated kinetics properties between 3-O- and 7-O- glucuronidation indicated that at least two distinct binding modes within the catalytic domain were responsible for the formation of these two glucuronide isomers. PMID:21472492

  5. Flavonol-carbon nanostructure hybrid systems: a DFT study on the interaction mechanism and UV/Vis features.

    PubMed

    García, Gregorio; Atilhan, Mert; Aparicio, Santiago

    2016-02-14

    Flavonols are a class of natural compounds with potential biological and pharmacological applications. They are also natural pigments responsible for the diversity of colors in plants. Flavonols offer the possibility of tuning their features through chemical functionalization as well as the presence of an aromatic backbone, which could lead to non-covalent interactions with different nanostructures or aromatic molecules. In this work, a protocol based on ONIOM (QM/QM) calculations to investigate the structural features (binding energies, intermolecular interactions) of flavonols interacting with the surface of several carbon nanostructures (such as graphene, fullerene C60 and carbon nanotubes) is developed. The confinement of flavonols inside carbon nanotubes has also been studied. Three flavonols, galangin, quercetin and myricetin, as well as pristine flavone were selected. Special attention has also been paid to the changes in UV/Vis features of flavonols due to the interaction with carbon nanostructures. Our results point out that π-stacking interactions are the driving force for the adsorption onto carbon nanostructures as well as for the confinement inside carbon nanotubes. Likewise, UV/Vis features of flavonols could be fine-tuned through the interaction with suitable carbon nanostructures.

  6. ROMPgel beads in IRORI format: acylations revisited.

    PubMed

    Roberts, Richard S

    2005-01-01

    Functionalized "designer" polymers derived from ring-opening metathesis polymerization (ROMPgels) are attractive for their high loading, high purity, and ease of synthesis. Their physical state may vary from liquid to gel to granular solid, making a general method of handling these polymers difficult. By incorporating a suitable norbornene-substituted linker on standard Wang beads, ROMPgels can be easily grafted onto the resin, adding the convenience of a bead format while still maintaining the high loading and excellent site accessibility. This advantage is demonstrated by the use of an N-hydroxysuccinimide ROMPgel (3.3 mmol g(-1), a 3-fold increase from the parent linker resin) in IRORI Kan format. Conditions for the acylation of these IRORI-formatted ROMPgels are reported, along with the scope and limitations of the choice of acylating reagents. Yields are greatly improved by the use of perfluorinated solvents as a nonparticipating cosolvent in the acylation process. A simple titration method for the quantification of the acylated ROMPgels is also reported. Spent Kans are regenerated after each use without apparent loss of activity or purity after several cycles. Due to the high loading and reduced swelling of the ROMPgel resin, up to 0.39 mmol acyl group has successfully been recovered from a single IRORI miniKan, demonstrating the high capacity of the resin and applicability to both lead discovery and optimization programs.

  7. In silico prediction of acyl glucuronide reactivity

    NASA Astrophysics Data System (ADS)

    Potter, Tim; Lewis, Richard; Luker, Tim; Bonnert, Roger; Bernstein, Michael A.; Birkinshaw, Timothy N.; Thom, Stephen; Wenlock, Mark; Paine, Stuart

    2011-11-01

    Drugs and drug candidates containing a carboxylic acid moiety, including many widely used non-steroidal anti-inflammatory drugs (NSAIDs) are often metabolized to form acyl glucuronides (AGs). NSAIDs such as Ibuprofen are amongst the most widely used drugs on the market, whereas similar carboxylic acid drugs such as Suprofen have been withdrawn due to adverse events. Although the link between these AG metabolites and toxicity is not proven, there is circumstantial literature evidence to suggest that more reactive acyl glucuronides may, in some cases, present a greater risk of exhibiting toxic effects. We wished therefore to rank the reactivity of potential new carboxylate-containing drug candidates, and performed kinetic studies on synthetic acyl glucuronides to benchmark our key compounds. Driven by the desire to quickly rank the reactivity of compounds without the need for lengthy synthesis of the acyl glucuronide, a correlation was established between the degradation half-life of the acyl glucuronide and the half life for the hydrolysis of the more readily available methyl ester derivative. This finding enabled a considerable broadening of chemical property space to be investigated. The need for kinetic measurements was subsequently eliminated altogether by correlating the methyl ester hydrolysis half-life with the predicted 13C NMR chemical shift of the carbonyl carbon together with readily available steric descriptors in a PLS model. This completely in silico prediction of acyl glucuronide reactivity is applicable within the earliest stages of drug design with low cost and acceptable accuracy to guide intelligent molecular design. This reactivity data will be useful alongside the more complex additional pharmacokinetic exposure and distribution data that is generated later in the drug discovery process for assessing the overall toxicological risk of acidic drugs.

  8. Twisting of glycosidic bonds by hydrolases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Patterns of scissile bond twisting have been found in crystal structures of glycoside hydrolases (GHs) that are complexed with substrates and inhibitors. To estimate the increased potential energy in the substrates that results from this twisting, we have plotted torsion angles for the scissile bond...

  9. Anticancer activity of sea cucumber triterpene glycosides.

    PubMed

    Aminin, Dmitry L; Menchinskaya, Ekaterina S; Pisliagin, Evgeny A; Silchenko, Alexandra S; Avilov, Sergey A; Kalinin, Vladimir I

    2015-03-06

    Triterpene glycosides are characteristic secondary metabolites of sea cucumbers (Holothurioidea, Echinodermata). They have hemolytic, cytotoxic, antifungal, and other biological activities caused by membranotropic action. These natural products suppress the proliferation of various human tumor cell lines in vitro and, more importantly, intraperitoneal administration in rodents of solutions of some sea cucumber triterpene glycosides significantly reduces both tumor burden and metastasis. The anticancer molecular mechanisms include the induction of tumor cell apoptosis through the activation of intracellular caspase cell death pathways, arrest of the cell cycle at S or G2/M phases, influence on nuclear factors, NF-κB, and up-down regulation of certain cellular receptors and enzymes participating in cancerogenesis, such as EGFR (epidermal growth factor receptor), Akt (protein kinase B), ERK (extracellular signal-regulated kinases), FAK (focal adhesion kinase), MMP-9 (matrix metalloproteinase-9) and others. Administration of some glycosides leads to a reduction of cancer cell adhesion, suppression of cell migration and tube formation in those cells, suppression of angiogenesis, inhibition of cell proliferation, colony formation and tumor invasion. As a result, marked growth inhibition of tumors occurs in vitro and in vivo. Some holothurian triterpene glycosides have the potential to be used as P-gp mediated MDR reversal agents in combined therapy with standard cytostatics.

  10. Anticancer Activity of Sea Cucumber Triterpene Glycosides

    PubMed Central

    Aminin, Dmitry L.; Menchinskaya, Ekaterina S.; Pisliagin, Evgeny A.; Silchenko, Alexandra S.; Avilov, Sergey A.; Kalinin, Vladimir I.

    2015-01-01

    Triterpene glycosides are characteristic secondary metabolites of sea cucumbers (Holothurioidea, Echinodermata). They have hemolytic, cytotoxic, antifungal, and other biological activities caused by membranotropic action. These natural products suppress the proliferation of various human tumor cell lines in vitro and, more importantly, intraperitoneal administration in rodents of solutions of some sea cucumber triterpene glycosides significantly reduces both tumor burden and metastasis. The anticancer molecular mechanisms include the induction of tumor cell apoptosis through the activation of intracellular caspase cell death pathways, arrest of the cell cycle at S or G2/M phases, influence on nuclear factors, NF-κB, and up-down regulation of certain cellular receptors and enzymes participating in cancerogenesis, such as EGFR (epidermal growth factor receptor), Akt (protein kinase B), ERK (extracellular signal-regulated kinases), FAK (focal adhesion kinase), MMP-9 (matrix metalloproteinase-9) and others. Administration of some glycosides leads to a reduction of cancer cell adhesion, suppression of cell migration and tube formation in those cells, suppression of angiogenesis, inhibition of cell proliferation, colony formation and tumor invasion. As a result, marked growth inhibition of tumors occurs in vitro and in vivo. Some holothurian triterpene glycosides have the potential to be used as P-gp mediated MDR reversal agents in combined therapy with standard cytostatics. PMID:25756523

  11. Antiproliferative steroidal glycosides from Digitalis ciliata.

    PubMed

    Perrone, Angela; Capasso, Anna; Festa, Michela; Kemertelidze, Ether; Pizza, Cosimo; Skhirtladze, Alexandre; Piacente, Sonia

    2012-04-01

    Two new compounds, a furostanol glycoside (1) and a pregnane glycoside (4), along with eight known compounds, belonging to the classes of spirostane (2,3), pregnane (5-7) and cardenolide (8-10) glycosides, were isolated from the seeds of Digitalis ciliata. Their structures were elucidated by 1D and 2D-NMR experiments as well as ESI-MS analysis. For the first time pregnane glycosides of the diginigenin series have been isolated from D. ciliata. The cytotoxic effects of compounds 1-10 on cell viability of several cancer cell lines, namely human breast cancer (MCF-7), human glioblastoma (T98G), human lung adenocarcinoma (A549), human colon carcinoma (HT-29), and human prostate cancer (PC-3) cell lines were evaluated. Compounds 1, 4, 7 and 8 showed antiproliferative effects against MCF-7, HT-29 and A549 cancer cells with IC₅₀ values ranging from 8.3 to 20 μM. The effects of compounds 1-10 on cell proliferation were evaluated on these three cancer cell lines by cell cycle analysis of DNA content using flow cytometry. Compounds 7, 8 and 10 induced significant changes in G₂/M cell cycle phase of all analyzed cells. The obtained results indicate that compounds 7, 8 and 10 are cytostatic compounds effective in reducing cell proliferation by inducing accumulation of the cells in the G₂/M phase of the cell cycle.

  12. Glycosides of the Magydaris pastinacea L.

    PubMed

    Cerri, R; Dessì, G; Manconi, P M; Serra, D; Pau, A

    1988-12-01

    From the alcoholic extract of fresh rhizomes from Magydaris pastinacea the glycosidic fraction was separated: it appears to be made up of seven different constituents one of which, 7-0-beta-D-glucopyranosil-8(2',3'-dihydroxy-3'methyl)-butylcoum arin isolated and identified by us, is relatively more abundant.

  13. A new isoflavone glycoside from Pueraria alopecuroides.

    PubMed

    Yang, Junlin; Fan, Qingfei; Zhang, Huanli; Song, Qishi

    2016-01-01

    A new isoflavone glycoside, (-)-tuberosin-3-O-β-D-glucopyranoside (1), along with 10 known compounds 1a-10, was isolated from Pueraria alopecuroides. Their structures were determined on the basis of spectral data including 1D and 2D NMR and HREIMS. These compounds were isolated from this plant for the first time.

  14. New oxypregnane glycosides from Caralluma penicillata.

    PubMed

    Abdel-Sattar, Essam; Meselhy, Meselhy R; Al-Yahya, Mohammed Abdul-Aziz

    2002-05-01

    The ether fraction of the defatted ethanol extract of the aerial parts of Caralluma penicillata (defl) M. E. Br. (Asclepiadaceae) yielded four new oxypregnane glycosides, penicillosides D-G. The structures of the isolated compounds were established by different spectroscopic methods.

  15. Triterpene glycosides of sea cucumbers (Holothuroidea, Echinodermata) as taxonomic markers.

    PubMed

    Kalinin, Vladimir I; Avilov, Sergey A; Silchenko, Alexandra S; Stonik, Valentin A

    2015-01-01

    Triterpene glycosides are characteristic metabolites of sea cucumbers (Holothurioidea, Echinodermata). The majority of the glycosides belong to the holostane type {lanostane derivatives with an 18(20)-lactone}. Carbohydrate chains of these glycosides contain xylose, glucose, quinovose, 3-O-methylglucose, and, rarely, 3-O-methylxylose, 3-O-methylglucuronic acid, 3-O-methylquinovose, and 6-O-acetyl-glucose. The glycosides are specific for genera, groups of genera and even for species. The advantages and problems in the use of triterpene glycosides as taxonomic markers in the systematics of sea cucumbers are discussed.

  16. Enzymatic Processing of Bioactive Glycosides from Natural Sources

    NASA Astrophysics Data System (ADS)

    Weignerová, Lenka; Křen, Vladimír

    A number of biologically active natural products are glycosides. Often, the glycosidic residue is crucial for their activity. In other cases, glycosylation only improves their pharmacokinetic parameters. Enzymatic modification of these glycosides - both extension of the glycoside moiety and its selective trimming - is advantageous due to their selectivity and mildness of the reaction conditions in the presence of reactive and sensitive complex aglycones. Enzymatic reactions enable the resulting products to be used as "natural products", e.g., in nutraceuticals. This chapter concentrates on naturally occurring glycosides used in medicine but also in the food and flavor industry (e.g., sweeteners). Both "classical" and modern methods will be discussed.

  17. Acyl-coenzyme A:cholesterol acyltransferases

    PubMed Central

    Chang, Ta-Yuan; Li, Bo-Liang; Chang, Catherine C. Y.; Urano, Yasuomi

    2009-01-01

    The enzymes acyl-coenzyme A (CoA):cholesterol acyltransferases (ACATs) are membrane-bound proteins that utilize long-chain fatty acyl-CoA and cholesterol as substrates to form cholesteryl esters. In mammals, two isoenzymes, ACAT1 and ACAT2, encoded by two different genes, exist. ACATs play important roles in cellular cholesterol homeostasis in various tissues. This chapter summarizes the current knowledge on ACAT-related research in two areas: 1) ACAT genes and proteins and 2) ACAT enzymes as drug targets for atherosclerosis and for Alzheimer's disease. PMID:19141679

  18. Acyl silicates and acyl aluminates as activated intermediates in peptide formation on clays

    NASA Technical Reports Server (NTRS)

    White, D. H.; Kennedy, R. M.; Macklin, J.

    1984-01-01

    Glycine reacts with heating on dried clays and other minerals to give peptides in much better yield than in the absence of mineral. This reaction was proposed to occur by way of an activated intermediate such as an acyl silicate or acyl aluminate analogous to acyl phosphates involved in several biochemical reactions including peptide bond synthesis. The proposed mechanism has been confirmed by trapping the intermediate, as well as by direct spectroscopic observation of a related intermediate. The reaction of amino acids on periodically dried mineral surfaces represents a widespead, geologically realistic setting for prebiotic peptide formation via in situ activation.

  19. Advance on the Flavonoid C-glycosides and Health Benefits.

    PubMed

    Xiao, Jianbo; Capanoglu, Esra; Jassbi, Amir Reza; Miron, Anca

    2016-07-29

    The dietary flavonoids, especially their glycosides, are the most vital phytochemicals in diets and are of great general interest due to their diverse bioactivity. Almost all natural flavonoids exist as their O-glycoside or C-glycoside forms in plants. The dietary flavonoid C-glycosides have received less attention than their corresponding O-glycosides. This review summarizes current knowledge regarding flavonoid C-glycosides and their influence on human health. Among the flavonoid C-glycosides, flavone C-glycosides, especially vitexin, isoorientin, orientin, isovitexin and their multiglycosides are more frequently mentioned than others. Flavonoid C-monoglycosides are poorly absorbed in human beings with very few metabolites in urine and blood and are deglycosylated and degraded by human intestinal bacteria in colon. However, flavonoid C-multiglycosides are absorbed unchanged in the intestine and distributed to other tissues. Flavonoid C-glycosides showed significant antioxidant activity, anticancer and antitumor activity, hepatoprotective activity, anti-inflammatory activity, anti-diabetes activity, antiviral activity, antibacterial and antifungal activity, and other biological effects. It looks like that the C-glycosylflavonoids in most cases showed higher antioxidant and anti-diabetes potential than their corresponding O-glycosylflavonoids and aglycones. However, there is a lack of in vivo data on the biological benefits of flavonoid C-glycosides. It is necessary to investigate more on how flavonoid C-glycosides prevent and handle the diseases.

  20. Acyl anion free N-heterocyclic carbene organocatalysis.

    PubMed

    Ryan, Sarah J; Candish, Lisa; Lupton, David W

    2013-06-21

    Reaction discovery using N-heterocyclic carbene organocatalysis has been dominated by the chemistry of acyl anion equivalents. Recent studies demonstrate that NHCs are far more diverse catalysts, with a variety of reactions discovered that proceed without acyl anion equivalent formation. In this tutorial review selected examples of acyl anion free NHC catalysis using carbonyl compounds are presented.

  1. A novel glucosylation reaction on anthocyanins catalyzed by acyl-glucose-dependent glucosyltransferase in the petals of carnation and delphinium.

    PubMed

    Matsuba, Yuki; Sasaki, Nobuhiro; Tera, Masayuki; Okamura, Masachika; Abe, Yutaka; Okamoto, Emi; Nakamura, Haruka; Funabashi, Hisakage; Takatsu, Makoto; Saito, Mikako; Matsuoka, Hideaki; Nagasawa, Kazuo; Ozeki, Yoshihiro

    2010-10-01

    Glucosylation of anthocyanin in carnations (Dianthus caryophyllus) and delphiniums (Delphinium grandiflorum) involves novel sugar donors, aromatic acyl-glucoses, in a reaction catalyzed by the enzymes acyl-glucose-dependent anthocyanin 5(7)-O-glucosyltransferase (AA5GT and AA7GT). The AA5GT enzyme was purified from carnation petals, and cDNAs encoding carnation Dc AA5GT and the delphinium homolog Dg AA7GT were isolated. Recombinant Dc AA5GT and Dg AA7GT proteins showed AA5GT and AA7GT activities in vitro. Although expression of Dc AA5GT in developing carnation petals was highest at early stages, AA5GT activity and anthocyanin accumulation continued to increase during later stages. Neither Dc AA5GT expression nor AA5GT activity was observed in the petals of mutant carnations; these petals accumulated anthocyanin lacking the glucosyl moiety at the 5 position. Transient expression of Dc AA5GT in petal cells of mutant carnations is expected to result in the transfer of a glucose moiety to the 5 position of anthocyanin. The amino acid sequences of Dc AA5GT and Dg AA7GT showed high similarity to glycoside hydrolase family 1 proteins, which typically act as β-glycosidases. A phylogenetic analysis of the amino acid sequences suggested that other plant species are likely to have similar acyl-glucose-dependent glucosyltransferases.

  2. High acyl gellan as an emulsion stabilizer.

    PubMed

    Vilela, Joice Aline Pires; da Cunha, Rosiane Lopes

    2016-03-30

    High acyl gellan (0.01-0.2% w/w) was used as stabilizer in oil in water emulsions containing 30% (w/w) of sunflower oil and prepared under different process conditions. Stable emulsions to phase separation could be obtained using high acyl gellan (HA) content above 0.05% (w/w), while low acyl gellan (LA) prepared at the same conditions could not stabilize emulsions. Emulsions properties depended on the process used to mix the oil and gellan dispersion since high pressure homogenization favored stabilization while very high energy density applied by ultrasound led to systems destabilization. Emulsions prepared using high pressure homogenization showed zeta potential values ranging from -50 up to -59 mV, suggesting that electrostatic repulsion could be contributing to the systems stability. Rheological properties of continuous phase were also responsible for emulsions stabilization, since HA gellan dispersions showed high viscosity and gel-like behavior. The high viscosity of the continuous phase could be associated to the presence of high acyl gellan microgels/aggregates. Disentanglement of these aggregates performed by ultrasound strongly decreased the viscosity and consequently affected the emulsions behavior, reducing the stability to phase separation.

  3. Domestication in Murtilla (Ugni molinae) Reduced Defensive Flavonol Levels but Increased Resistance Against a Native Herbivorous Insect.

    PubMed

    Chacón-Fuentes, Manuel; Parra, Leonardo; Rodriguez-Saona, Cesar; Seguel, Ivette; Ceballos, Ricardo; Quiroz, Andres

    2015-06-01

    Plant domestication can have negative consequences for defensive traits against herbivores, potentially reducing the levels of chemical defenses in plants and consequently their resistance against herbivores. We characterized and quantified the defensive flavonols from multiple cultivated ecotypes with wild ancestors of murtilla, Ugni molinae Turcz, an endemic plant from Chile, at different times of the year, and examined their effects on a native insect herbivore, Chilesia rudis Butler (Lepidoptera: Arctiidae). We hypothesized that domestication results in a decrease in flavonol levels in U. molinae plants, and that this negatively affected C. rudis performance and preference. Ethanolic extracts were made from leaves, stems, and fruit of murtilla plants for flavonol analysis. Flavonols identified were kaempferol, quercetin, rutin, and quercetin 3-D-β-glucoside, the last two being the most abundant. More interestingly, we showed differences in flavonol composition between wild and cultivated U. molinae that persisted for most of the year. Relative amounts of all four flavonols were higher in wild U. molinae leaves; however, no differences were found in the stem and fruit between wild and cultivated plants. In choice and no-choice assays, C. rudis larvae gained more mass on, and consumed more leaf material of, wild as compared with cultivated U. molinae plants. Moreover, when applied to leaves, larvae ate more leaf material with increasing concentrations of each flavonol compound. Our study demonstrates that domestication in U. molinae reduced the amount of flavonols in leaves as well as the performance and preference of C. rudis, indicating that these compounds stimulate feeding of C. rudis.

  4. Synthesis of glycosyl amino acids by light-induced coupling of photoreactive amino acids with glycosylamines and 1-C-aminomethyl glycosides.

    PubMed

    Simo, Ondrej; Lee, Vincent P; Davis, Alexander S; Kreutz, Christian; Gross, Paul H; Jones, Patrick R; Michael, Katja

    2005-03-21

    The glycosylamines of O-acetyl-protected GlcNAc and chitobiose, as well as two partially unprotected 1-C-aminomethyl glucosides, were photochemically coupled with orthogonally protected N-aspartyl-5-bromo-7-nitroindoline derivatives. The reactions proceeded under neutral conditions by irradiation with near-UV light. The glycosyl asparagines with N- or C-glycosyl linkages were afforded in 60-85% yield on a 10-70 mg scale. Moreover, the ability of a highly photoreactive N-glutamyl-4-methoxy-7-nitroindoline derivative to acylate amino saccharides was tested. Upon irradiation in the presence of a dimeric 1-C-aminomethyl glycoside, or a glycosylamine, the corresponding glycosyl glutamines were obtained in 50% and 30% yield, respectively. Preparations of the photoreactive aspartates and the 1-C-aminomethyl glycosides are also described.

  5. Flower color changes in three Japanese hibiscus species: further quantitative variation of anthocyanin and flavonols.

    PubMed

    Shimokawa, Satoshi; Iwashina, Tsukasa; Murakami, Noriaki

    2015-03-01

    One anthocyanin and four flavonols were detected from the petals of Hibiscus hamabo, H. tiliaceus and H. glaber. They were identified as cyanidin 3-0- sambubioside, gossypetin 3-O-glucuronide-8-O-glucoside, quercetin 7-O-rutinoside, gossypetin 3-O-glucoside and gossypetin 8-O-glucuronide by UV spectra, LC-MS, acid hydrolysis and HPLC. The flavonoid composition was essentially the same among the petals ofH. hamabo, H. tiliaceus and H. glaber, and there was little quantitative variation, except for cyanidin 3-O-sambubioside, the content of which in the petals ofH. tiliaceus and H. glaber was much higher than in that of H. hamabo. Flower colors of H. tiliaceus and H. glaber change from yellow to red, and that of H. hamabo changes from yellow to orange. These changes were caused by contents of anthocyanin and flavonols, which increased after flowering of H. hamabo, H. tiliaceus and H. glaber.

  6. Glucosinolates, myrosinase hydrolysis products, and flavonols found in rocket (Eruca sativa and Diplotaxis tenuifolia).

    PubMed

    Bell, Luke; Wagstaff, Carol

    2014-05-21

    Rocket species have been shown to have very high concentrations of glucosinolates and flavonols, which have numerous positive health benefits with regular consumption. This review highlights how breeders and processors of rocket species can utilize genomic and phytochemical research to improve varieties and enhance the nutritive benefits to consumers. Plant breeders are increasingly looking to new technologies such as HPLC, UPLC, LC-MS, and GC-MS to screen populations for their phytochemical content to inform plant selections. This paper collates the research that has been conducted to date in rocket and summarizes all glucosinolate and flavonol compounds identified in the species. The paper emphasizes the importance of the broad screening of populations for phytochemicals and myrosinase degradation products, as well as unique traits that may be found in underutilized gene bank resources. This review also stresses that collaboration with industrial partners is becoming essential for long-term plant breeding goals through research.

  7. Acylation of the Type 3 Secretion System Translocon Using a Dedicated Acyl Carrier Protein

    PubMed Central

    Agrebi, Rym; Canestrari, Mickaël J.; Mignot, Tâm; Lebrun, Régine; Bouveret, Emmanuelle

    2017-01-01

    Bacterial pathogens often deliver effectors into host cells using type 3 secretion systems (T3SS), the extremity of which forms a translocon that perforates the host plasma membrane. The T3SS encoded by Salmonella pathogenicity island 1 (SPI-1) is genetically associated with an acyl carrier protein, IacP, whose role has remained enigmatic. In this study, using tandem affinity purification, we identify a direct protein-protein interaction between IacP and the translocon protein SipB. We show, by mass spectrometry and radiolabelling, that SipB is acylated, which provides evidence for a modification of the translocon that has not been described before. A unique and conserved cysteine residue of SipB is identified as crucial for this modification. Although acylation of SipB was not essential to virulence, we show that this posttranslational modification promoted SipB insertion into host-cell membranes and pore-forming activity linked to the SPI-1 T3SS. Cooccurrence of acyl carrier and translocon proteins in several γ- and β-proteobacteria suggests that acylation of the translocon is conserved in these other pathogenic bacteria. These results also indicate that acyl carrier proteins, known for their involvement in metabolic pathways, have also evolved as cofactors of new bacterial protein lipidation pathways. PMID:28085879

  8. Molar absorptivity and color characteristics of acylated and non-acylated pelargonidin-based anthocyanins.

    PubMed

    Giusti, M M; Rodríguez-Saona, L E; Wrolstad, R E

    1999-11-01

    The effects of glycosylation and acylation on the spectral characteristics, molar absorptivity, and color attributes of purified acylated and non-acylated pelargonidin derivatives were compared. Pigments were obtained from strawberries, radishes, red-fleshed potatoes, and partially hydrolyzed radish pigments. Individual pigments were isolated by using semipreparative HPLC. Spectral and color (CIELch) attributes of purified pigments were measured. Molar absorptivity ranged from 15 600 to 39 590 for pelargonidin-3-glucoside (pg-3-glu) and pg-3-rutinoside-5-glucoside acylated with p-coumaric acid, respectively. The presence of cinnamic acid acylation had a considerable impact on spectral and color characteristics, causing a bathochromic shift of lambda(max). Sugar substitution also played an important role, with a hypsochromic shift caused by the presence of glycosylation. Pg-3, 5-diglu and pg-3,5-triglu possessed a higher hue angle (>40 degrees ) than the other pg derivatives at pH 1.0, corresponding to the yellow-orange region of the color solid. Acylation with malonic acid did not affect lambda(max) and showed little effect on color characteristics. The solvent system had an effect not only on the molar absorptivity, but also on the visual color characteristic of the pigments.

  9. Flavonols enhanced production of anti-inflammatory substance(s) by Bifidobacterium adolescentis: prebiotic actions of galangin, quercetin, and fisetin.

    PubMed

    Kawabata, Kyuichi; Sugiyama, Yuta; Sakano, Taiken; Ohigashi, Hajime

    2013-01-01

    The gut microbiota is capable of the bioconversion of flavonoids whereas influences of probiotic anaerobes on the bioactivities of flavonoids and vice versa are still unclear. Here, we investigated functional interactions with respect to the anti-inflammatory activity between flavonols and probiotic bacteria. Ten enteric (6 probiotic and 4 indigenous) bacteria were incubated with flavonols (galangin, kaempferol, quercetin, myricetin, and fisetin) under anaerobic conditions, and the supernatants were assessed for their effects on nitric oxide (NO) production in lipopolysaccaride-stimulated RAW264 cells. Although the conditioned medium from the flavonol mono-culture and almost all of the tested co-cultures failed to inhibit NO production, the medium from the Bifidobacterium adolescentis/flavonols (galangin, quercetin, and fisetin) co-culture highly suppressed NO production. This activity increased during the 1-6 H incubation in a time-dependent manner and was not observed in the co-culture using heat-inactivated B. adolescentis. Interestingly, when the B. adolescentis cell number was increased, the supernatant from the mono-culture of the bacteria showed NO suppression, suggesting that B. adolescentis may produce NO suppressant(s), and flavonols may have a promoting effect. These findings indicate that flavonols have a prebiotic-like effect on the anti-inflammatory activity of B. adolescentis.

  10. The antiradical activity of some selected flavones and flavonols. Experimental and quantum mechanical study.

    PubMed

    Sroka, Zbigniew; Żbikowska, Beata; Hładyszowski, Jerzy

    2015-12-01

    The aim of the study was to examine the antiradical and antioxidant activity of some flavones and flavonols with different models of hydroxylation and methoxylation. Antiradical activity was measured using ABTS and DPPH radicals and ferric ions (FRAP test). The reduction potential of the compounds was also investigated by determination of minimal hydrogen abstraction energy for each of the hydroxyl hydrogens of all compounds using quantum chemistry methods. Quercetin appeared to be a strong antioxidant when the FRAP test was performed and the strongest for ABTS and DPPH tests whereas genkwanin was the weakest antioxidant for three tests (FRAP, ABTS, and DPPH). Flavonols appeared to have much stronger antiradical activity than flavones. An exception was luteolin, which belongs to flavones but exhibited antiradical activity comparable to that of flavonols, probably due to the presence of a hydroxyl group in the B ring at the 3' position next to another hydroxyl group at position 4'. The study using UB3LYP/6-31G(d,p) model chemistry of density functional theory (DFT) showed the lowest hydrogen abstraction energy (HAE) for the hydroxyl group situated at 3' or 5' of myricetin. Based on the experimental results and computational studies, we conclude that the hydroxyl group situated at 4' in the B ring in flavonoids, and to a lesser at the 3' and 3 position in flavonols is the most important for antioxidant activity of flavonoids. We observe strong negative Spearman's rank order correlations between minimal HAE and antiradical activity of flavonoids in all three tests and double-tailed rejection P values are less than 0.001.

  11. Protective Role of Ternatin Anthocyanins and Quercetin Glycosides from Butterfly Pea (Clitoria ternatea Leguminosae) Blue Flower Petals against Lipopolysaccharide (LPS)-Induced Inflammation in Macrophage Cells.

    PubMed

    Nair, Vimal; Bang, Woo Young; Schreckinger, Elisa; Andarwulan, Nuri; Cisneros-Zevallos, Luis

    2015-07-22

    Twelve phenolic metabolites (nine ternatin anthocyanins and three glycosylated quercetins) were identified from the blue flowers of Clitoria ternatea by high-performance liquid chromatography diode array detection and electrospray ionization/mass spectrometry (HPLC-DAD-ESI/MS(n)). Three anthocyanins not reported in this species before show fragmentation pattern of the ternatin class. Extracts were fractionated in fractions containing flavonols (F3) and ternatin anthocyanins (F4). In general, C. ternatea polyphenols showed anti-inflammatory properties in lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells with distinct molecular targets. Flavonols (F3) showed strong inhibition of COX-2 activity and partial ROS suppression. On the other hand, the ternatin anthocyanins (F4) inhibited nuclear NF-κB translocation, iNOS protein expression, and NO production through a non-ROS suppression mechanism. Accordingly, quercetin glycosides and ternatin anthocyanins from the blue flower petals of C. ternatea may be useful in developing drugs or nutraceuticals for protection against chronic inflammatory diseases by suppressing the excessive production of pro-inflammatory mediators from macrophage cells.

  12. Cloning and Characterization of a Flavonol Synthase Gene from Scutellaria baicalensis

    PubMed Central

    Kim, Yeon Bok; Kim, KwangSoo; Kim, YeJi; Tuan, Pham Anh; Kim, Haeng Hoon; Cho, Jin Woong; Park, Sang Un

    2014-01-01

    Flavonols are the most abundant of all the flavonoids and play pivotal roles in a variety of plants. We isolated a cDNA clone encoding flavonol synthase from Scutellaria baicalensis (SbFLS). The SbFLS cDNA is 1011 bp long, encodes 336 amino acid residues, and belongs to a family of 2-oxoglutarate-dependent dioxygenases. The overall structure of SbFLS is very similar to that of Arabidopsis thaliana anthocyanidin synthase (AtANS), with a β jelly-roll fold surrounded by tens of short and long α-helices. SbFLS was constitutively expressed in the roots, stems, leaves, and flowers, with particularly high expression in the roots and flowers. SbFLS transcript levels in the roots were 376-, 70-, and 2.5-fold higher than in the leaves, stems, and flowers. The myricetin content was significantly higher than that of kaempferol and quercetin. Therefore, we suggest that SbFLS mediates flavonol formation in the different organs of S. baicalensis. Our study may contribute to the knowledge of the role of FLS in S. baicalensis. PMID:24672406

  13. Functional Analysis of a Predicted Flavonol Synthase Gene Family in Arabidopsis1[W][OA

    PubMed Central

    Owens, Daniel K.; Alerding, Anne B.; Crosby, Kevin C.; Bandara, Aloka B.; Westwood, James H.; Winkel, Brenda S.J.

    2008-01-01

    The genome of Arabidopsis (Arabidopsis thaliana) contains five sequences with high similarity to FLAVONOL SYNTHASE1 (AtFLS1), a previously characterized flavonol synthase gene that plays a central role in flavonoid metabolism. This apparent redundancy suggests the possibility that Arabidopsis uses multiple isoforms of FLS with different substrate specificities to mediate the production of the flavonols, quercetin and kaempferol, in a tissue-specific and inducible manner. However, biochemical and genetic analysis of the six AtFLS sequences indicates that, although several of the members are expressed, only AtFLS1 encodes a catalytically competent protein. AtFLS1 also appears to be the only member of this group that influences flavonoid levels and the root gravitropic response in seedlings under nonstressed conditions. This study showed that the other expressed AtFLS sequences have tissue- and cell type-specific promoter activities that overlap with those of AtFLS1 and encode proteins that interact with other flavonoid enzymes in yeast two-hybrid assays. Thus, it is possible that these “pseudogenes” have alternative, noncatalytic functions that have not yet been uncovered. PMID:18467451

  14. Variation of Select Flavonols and Chlorogenic Acid Content of Elderberry Collected Throughout the Eastern United States

    PubMed Central

    Mudge, Elizabeth; Applequist, Wendy L.; Finley, Jamie; Lister, Patience; Townesmith, Andrew K.; Walker, Karen M.; Brown, Paula N.

    2016-01-01

    American elderberries are commonly collected from wild plants for use as food and medicinal products. The degree of phytochemical variation amongst wild populations has not been established and might affect the overall quality of elderberry dietary supplements. The three major flavonols identified in elderberries are rutin, quercetin and isoquercetin. Variation in the flavonols and chlorogenic acid was determined for 107 collections of elderberries from throughout the eastern United States using an optimized high performance liquid chromatography with ultraviolet detection method. The mean content was 71.9 mg per 100g fresh weight with variation ranging from 7.0 to 209.7 mg per 100 g fresh weight within the collected population. Elderberries collected from southeastern regions had significantly higher contents in comparison with those in more northern regions. The variability of the individual flavonol and chlorogenic acid profiles of the berries was complex and likely influenced by multiple factors. Several outliers were identified based on unique phytochemical profiles in comparison with average populations. This is the first study to determine the inherent variability of American elderberries from wild collections and can be used to identify potential new cultivars that may produce fruits of unique or high-quality phytochemical content for the food and dietary supplement industries. PMID:26877585

  15. A novel glycoside from Acanthus hirsutus (Acanthaceae).

    PubMed

    Capanlar, Seval; Böke, Nazli; Yaşa, Ihsan; Kirmizigül, Süheyla

    2010-04-01

    A novel glycoside, hirsutusoide (1), characterized as 2-(o-hydroxyphenyl)-2-hydroxyethenyl-O-beta-glucopyranoside, was isolated from the endemic Acanthus hirsutus Boiss. In addition to compound 1, three known glycosides, luteolin-7-O-beta-D-glucuronide (2), beta-sitosterol-3-O-beta-D-glucopyranoside (3) and (2R)-2-O-beta-D-glucopyranosyl-2H-1,4-benzoxazin-3(4H)-one (4), were also isolated. Compound 2 was the first report from this genus. Antimicrobial and antioxidant activity of the extracts and the novel compound were investigated by determining MIC (microg/mL) and IC50 (microg/mL) values, respectively.

  16. Phenolic glycosides from berries of Pimenta dioica.

    PubMed

    Kikuzaki, Hiroe; Miyajima, Yoshiko; Nakatani, Nobuji

    2008-05-01

    Four new phenolic glycosides, (2-hydroxy-3-methoxy-5-allyl)phenyl beta- d-(6-O-E-sinapoyl)glucopyranoside (1), (1' R,5' R)-5-(5-carboxymethyl-2-oxocyclopentyl)-3 Z-pentenyl beta-D-(6-O-galloyl)glucopyranoside (2), (S)-alpha-terpinyl [alpha-L-(2-O-galloyl)arabinofuranosyl]-(1-->6)-beta-D-glucopyranoside (3), and (R)-alpha-terpinyl [alpha-L-(2-O-galloyl)arabinofuranosyl]-(1-->6)-beta-D-glucopyranoside (4), were isolated from the berries of Pimenta dioica together with eight known flavonoids. The structures of 1-4 were elucidated on the basis of MS and NMR data and enzymatic hydrolysis. All four glycosides showed radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals.

  17. New pregnane glycosides from Gymnema sylvestre.

    PubMed

    Xu, Rui; Yang, Yu; Zhang, Yang; Ren, Fengxia; Xu, Jinlong; Yu, Nengjiang; Zhao, Yimin

    2015-02-12

    Four new pregnane glycosides 1-4 were isolated from the ethanol extract of the stem of Gymnema sylvestre and named gymsylvestrosides A-D. Hydrolysis of compound 1 under the catalysis of Aspergilus niger β-glucosidase afforded compound 5 (gymsylvestroside E). Their structures were determined by spectroscopic methods such as HRESIMS, 1D and 2D NMR, as well as HMQC-TOCSY experiment. Compounds 1-4 were screened for Saccharomyces cerevisiae α-glucosidase inhibitory activity.

  18. A new phenol glycoside from Physalis angulata.

    PubMed

    Sun, Cheng-Peng; Nie, Xiu-Fang; Kang, Ning; Zhao, Feng; Chen, Li-Xia; Qiu, Feng

    2017-05-01

    A new phenol glycoside, physanguloside A (1), was isolated from Physalis angulata together with four known compounds. We report herein, for the first time, the presence of compounds 2-5 in the genus Physalis. The structures of all the compounds were established by NMR, IR, UV and HRESIMS spectroscopic analyses, and comparison with the literature data. All isolated compounds were assayed for inhibitory activity on nitric oxide production by LPS-induced in RAW 264.7 macrophages.

  19. Triterpenoid glycosides from bark of Meliosma lanceolata.

    PubMed

    Abe, F; Yamauchi, T; Shibuya, H; Kitagawa, I

    1996-06-01

    From the bark of Meliosma lanceolate, nine triterpenoid glycosides including the 28-O-beta-D-glucopyranosyl ester of bayogenin-3-O-beta-D-glucuronopyranoside, its 4'-O-beta-D-galactopyranoside and 4'-O-alpha-L-arabinopyranoside were isolated and the structures characterized along with that of 28-O-beta-D-glucopyranosyl-bayogenin-3-O-beta-D-4'-anhydro-4', 5'-didehydroglucuronopyranoside. Bisdesmosidic triosides of hederagenin were obtained as minor components.

  20. Four Pentasaccharide Resin Glycosides from Argyreia acuta.

    PubMed

    Yu, Bang-Wei; Sun, Jing-Jing; Pan, Jie-Tao; Wu, Xiu-Hong; Yin, Yong-Qin; Yan, You-Shao; Hu, Jia-Yan

    2017-03-11

    Four pentasaccharide resin glycosides, acutacoside F-I (1-4), were isolated from the aerial parts of Argyreia acuta. These compounds were characterized as a group of macrolactones of operculinic acid A, and their lactonization site of 11S-hydroxyhexadecanoic acid was esterified at the second saccharide moiety (Rhamnose) at C-2. The absolute configuration of the aglycone was S. Their structures were elucidated by established spectroscopic and chemical methods.

  1. ent-Kaurene Glycosides from Ageratina cylindrica.

    PubMed

    Bustos-Brito, Celia; Sánchez-Castellanos, Mariano; Esquivel, Baldomero; Calderón, José S; Calzada, Fernando; Yépez-Mulia, Lilian; Joseph-Nathan, Pedro; Cuevas, Gabriel; Quijano, Leovigildo

    2015-11-25

    The aqueous extract of the leaves of Ageratina cylindrica afforded six new ent-kaurenoic acid glycosides together with the known diterpenoid paniculoside V, the flavonoid astragalin, chlorogenic acid, and L-chiro-inositol. The structures were elucidated mainly by NMR and MS methods, and the absolute configuration was established by vibrational circular dichroism spectroscopy. The new compounds showed moderate antiprotozoal activity against Entamoeba histolytica and Giardia lamblia trophozoites.

  2. A new lignan glycoside from Eleutherococcus senticosus.

    PubMed

    Li, X C; Barnes, D L; Khan, I A

    2001-11-01

    A new lignan glycoside, named eleutheroside E(2) (1), has been isolated from the roots of Eleutherococcus senticosus (known as "Siberian ginseng"), along with isomaltol 3-O-alpha-D-glucopyranoside (2), eleutherosides B, E and E(1), and thymidine. The structure of 1 was established by spectral interpretations as episyringaresinol 4"-O-beta-D-glucopyranoside. Compound 2 is described here for the first time as a naturally occurring compound.

  3. Head-group acylation of monogalactosyldiacylglycerol is a common stress response, and the acyl-galactose acyl composition varies with the plant species and applied stress.

    PubMed

    Vu, Hieu Sy; Roth, Mary R; Tamura, Pamela; Samarakoon, Thilani; Shiva, Sunitha; Honey, Samuel; Lowe, Kaleb; Schmelz, Eric A; Williams, Todd D; Welti, Ruth

    2014-04-01

    Formation of galactose-acylated monogalactosyldiacylglycerols has been shown to be induced by leaf homogenization, mechanical wounding, avirulent bacterial infection and thawing after snap-freezing. Here, lipidomic analysis using mass spectrometry showed that galactose-acylated monogalactosyldiacylglycerols, formed in wheat (Triticum aestivum) and tomato (Solanum lycopersicum) leaves upon wounding, have acyl-galactose profiles that differ from those of wounded Arabidopsis thaliana, indicating that different plant species accumulate different acyl-galactose components in response to the same stress. Additionally, the composition of the acyl-galactose component of Arabidopsis acMGDG (galactose-acylated monogalactosyldiacylglycerol) depends on the stress treatment. After sub-lethal freezing treatment, acMGDG contained mainly non-oxidized fatty acids esterified to galactose, whereas mostly oxidized fatty acids accumulated on galactose after wounding or bacterial infection. Compositional data are consistent with acMGDG being formed in vivo by transacylation with fatty acids from digalactosyldiacylglycerols. Oxophytodienoic acid, an oxidized fatty acid, was more concentrated on the galactosyl ring of acylated monogalactosyldiacylglycerols than in galactolipids in general. Also, oxidized fatty acid-containing acylated monogalactosyldiacylglycerols increased cumulatively when wounded Arabidopsis leaves were wounded again. These findings suggest that, in Arabidopsis, the pool of galactose-acylated monogalactosyldiacylglycerols may serve to sequester oxidized fatty acids during stress responses.

  4. Oleandrin: A cardiac glycosides with potent cytotoxicity

    PubMed Central

    Kumar, Arvind; De, Tanmoy; Mishra, Amrita; Mishra, Arun K.

    2013-01-01

    Cardiac glycosides are used in the treatment of congestive heart failure and arrhythmia. Current trend shows use of some cardiac glycosides in the treatment of proliferative diseases, which includes cancer. Nerium oleander L. is an important Chinese folk medicine having well proven cardio protective and cytotoxic effect. Oleandrin (a toxic cardiac glycoside of N. oleander L.) inhibits the activity of nuclear factor kappa-light-chain-enhancer of activated B chain (NF-κB) in various cultured cell lines (U937, CaOV3, human epithelial cells and T cells) as well as it induces programmed cell death in PC3 cell line culture. The mechanism of action includes improved cellular export of fibroblast growth factor-2, induction of apoptosis through Fas gene expression in tumor cells, formation of superoxide radicals that cause tumor cell injury through mitochondrial disruption, inhibition of interleukin-8 that mediates tumorigenesis and induction of tumor cell autophagy. The present review focuses the applicability of oleandrin in cancer treatment and concerned future perspective in the area. PMID:24347921

  5. Appetite suppressing pregnane glycosides from the roots of Cynanchum auriculatum.

    PubMed

    Liu, Shuangzhu; Chen, Zhenhua; Wu, Jian; Wang, Luoyi; Wang, Hongmin; Zhao, Weimin

    2013-09-01

    In the search for plant alternatives to Hoodia gordonii containing P57, a pregnane glycoside with potential appetite suppressant effect, the roots of Cynanchum auriculatum were investigated. As a result, 15 pregnane glycosides including nine never previously reported were isolated. Their structures were elucidated on the basis of extensive spectroscopic analyses and chemical methods. Appetite suppressant effect and body weight loss were observed when tested with the most abundant pregnane glycoside, wilfoside K1N, in an in vivo test with rats.

  6. New oxypregnane glycosides from appetite suppressant herbal supplement Hoodia gordonii.

    PubMed

    Pawar, Rahul S; Shukla, Yatin J; Khan, Shabana I; Avula, Bharathi; Khan, Ikhlas A

    2007-06-01

    Hoodigosides A-K (1-11), eleven new oxypregnane glycosides and a previously reported oxypregnane glycoside P57AS3 were isolated from the aerial parts of Hoodia gordonii. The structures of these 12-O-beta-tigloyl isoramanone glycosides were determined on the basis of chemical evidence and extensive spectroscopic methods that include one-dimensional and two-dimensional NMR. Cytotoxicity and antioxidant activities of these compounds were tested in cell based assays where they were found to be inactive.

  7. The Identification of Perillyl Alcohol Glycosides with Improved Antiproliferative Activity

    PubMed Central

    2015-01-01

    A facile route to perillyl alcohol (POH) differential glycosylation and the corresponding synthesis of a set of 34 POH glycosides is reported. Subsequent in vitro studies revealed a sugar dependent antiproliferative activity and the inhibition of S6 ribosomal protein phosphorylation as a putative mechanism of representative POH glycosides. The most active glycoside from this cumulative study (4′-azido-d-glucoside, PG9) represents one of the most cytotoxic POH analogues reported to date. PMID:25121720

  8. Cardiac glycosides from Yellow Oleander (Thevetia peruviana) seeds.

    PubMed

    Kohls, Sarah; Scholz-Böttcher, Barbara M; Teske, Jörg; Zark, Patrick; Rullkötter, Jürgen

    2012-03-01

    Thevetia cardiac glycosides can lead to intoxication, thus they are important indicators for forensic and pharmacologic surveys. Six thevetia cardiac glycosides, including two with unknown structures, were isolated from the seeds of the Yellow Oleander (Thevetia peruviana (Pers.) K. Shum., Apocynaceae). LC-ESI⁺-MS(/MS) analysis under high-resolution conditions used as a qualitative survey of the primary glycosides did not lead to fragmentation of the aglycones. Acid hydrolysis of the polar and non-volatile thevetia glycosides under severe conditions yielded the aglycones of the thevetia glycosides and made them amenable to GC-MS analysis. Comparison of mass spectral fragmentation patterns of the aglycones, as well as high-resolution mass spectrometric and NMR data of four of the primary thevetia glycosides including the two unknowns, revealed the structures of the complete set of six thevetia glycosides. The identified compounds are termed thevetin C and acetylthevetin C and differ by an 18,20-oxido-20,22-dihydro functionality from thevetin B and acetylthevetin B, respectively. The absence of an unsaturated lactone ring renders the glycosides cardio-inactive. The procedures developed in this study and the sets of analytical data obtained will be useful for screening and structure assessment of other, particularly polar, cardiac glycosides.

  9. Antifungal active triterpene glycosides from sea cucumber Holothuria scabra.

    PubMed

    Han, Hua; Yi, Yang-Hua; Li, Ling; Liu, Bao-Shu; La, Ming-Ping; Zhang, Hong-Wei

    2009-06-01

    To study the new antifungal active triterpene glycosides of sea cucumber Holothuria scabra. Triterpene glycosides from Holothuria scabra were separated and purified by silica gel chromatography, reversed-phase silica gel chromatography and RP-HPLC. Their structures were elucidated on the basis of spectral data and chemical evidence. Three triterpene glycosides were identified as scabraside A (1), echinoidea A (2) and holothurin A1 (3). Scabraside A (1) is a new triterpene glycoside, and compounds 2 and 3 were isolated from Holothuria scabra for the first time. They showed antifungal activities (1 < or = MIC80 < or = 16 microg mL(-1)).

  10. Acyl glucuronides: the good, the bad and the ugly.

    PubMed

    Regan, Sophie L; Maggs, James L; Hammond, Thomas G; Lambert, Craig; Williams, Dominic P; Park, B Kevin

    2010-10-01

    Acyl glucuronidation is the major metabolic conjugation reaction of most carboxylic acid drugs in mammals. The physiological consequences of this biotransformation have been investigated incompletely but include effects on drug metabolism, protein binding, distribution and clearance that impact upon pharmacological and toxicological outcomes. In marked contrast, the exceptional but widely disparate chemical reactivity of acyl glucuronides has attracted far greater attention. Specifically, the complex transacylation and glycation reactions with proteins have provoked much inconclusive debate over the safety of drugs metabolised to acyl glucuronides. It has been hypothesised that these covalent modifications could initiate idiosyncratic adverse drug reactions. However, despite a large body of in vitro data on the reactions of acyl glucuronides with protein, evidence for adduct formation from acyl glucuronides in vivo is limited and potentially ambiguous. The causal connection of protein adduction to adverse drug reactions remains uncertain. This review has assessed the intrinsic reactivity, metabolic stability and pharmacokinetic properties of acyl glucuronides in the context of physiological, pharmacological and toxicological perspectives. Although numerous experiments have characterised the reactions of acyl glucuronides with proteins, these might be attenuated substantially in vivo by rapid clearance of the conjugates. Consequently, to delineate a relationship between acyl glucuronide formation and toxicological phenomena, detailed pharmacokinetic analysis of systemic exposure to the acyl glucuronide should be undertaken adjacent to determining protein adduct concentrations in vivo. Further investigation is required to ascertain whether acyl glucuronide clearance is sufficient to prevent covalent modification of endogenous proteins and consequentially a potential immunological response.

  11. Multiple acyl-CoA dehydrogenation deficiency as decreased acyl-carnitine profile in serum.

    PubMed

    Wen, Bing; Li, Duoling; Li, Wei; Zhao, Yuying; Yan, Chuanzhu

    2015-06-01

    We report a case with late onset riboflavin-responsive multiple acyl-CoA dehydrogenation deficiency (MADD) characterized by decreased acyl-carnitine profile in serum which is consistent with primary systemic carnitine deficiency (CDSP) while just the contrary to a typical MADD. This patient complained with muscle weakness, muscle pain and intermittent vomiting, and was diagnosed as polymyositis, received prednisone therapy before consulted with us. Muscle biopsy revealed mild lipid storage. The findings of serum acyl-carnitines were consistent with CDSP manifesting as decreased free and total carnitines in serum. But oral L-carnitine supplementation was not very effective to this patient and mutation analysis of the SLC22A5 gene for CDSP was normal. Later, another acyl-carnitine analysis revealed a typical MADD profile in serum, which was characterized by increased multiple acyl-carnitines. Compound heterozygous mutations were identified in electron transferring-flavoprotein dehydrogenase (ETFDH) gene which confirmed the diagnosis of MADD. After administration of riboflavin, he improved dramatically, both clinically and biochemically. Thus, late onset riboflavin-responsive MADD should be included in the differential diagnosis for adult carnitine deficiency.

  12. Fatty Acyl Chains of Mycobacterium marinum Lipooligosaccharides

    PubMed Central

    Rombouts, Yoann; Alibaud, Laeticia; Carrère-Kremer, Séverine; Maes, Emmanuel; Tokarski, Caroline; Elass, Elisabeth; Kremer, Laurent; Guérardel, Yann

    2011-01-01

    We have recently established the fine structure of the glycan backbone of lipooligosaccharides (LOS-I to LOS-IV) isolated from Mycobacterium marinum, a close relative of Mycobacterium tuberculosis. These studies culminated with the description of an unusual terminal N-acylated monosaccharide that confers important biological functions to LOS-IV, such as macrophage activation, that may be relevant to granuloma formation. It was, however, also suggested that the lipid moiety was required for LOSs to exert their immunomodulatory activity. Herein, using highly purified LOSs from M. marinum, we have determined through a combination of mass spectrometric and NMR techniques, the structure and localization of the fatty acids composing the lipid moiety. The occurrence of two distinct polymethyl-branched fatty acids presenting specific localizations is consistent with the presence of two highly related polyketide synthases (Pks5 and Pks5.1) in M. marinum and presumably involved in the synthesis of these fatty acyl chains. In addition, a bioinformatic search permitted us to identify a set of enzymes potentially involved in the biosynthesis or transfer of these lipids to the LOS trehalose unit. These include MMAR_2343, a member of the Pap (polyketide-associated protein) family, that acylates trehalose-based glycolipids in M. marinum. The participation of MMAR_2343 to LOS assembly was demonstrated using a M. marinum mutant carrying a transposon insertion in the MMAR_2343 gene. Disruption of MMAR_2343 resulted in a severe LOS breakdown, indicating that MMAR_2343, hereafter designated PapA4, fulfills the requirements for LOS acylation and assembly. PMID:21803773

  13. Triterpene glycosides from the deep-water North-Pacific sea cucumber Synallactes nozawai Mitsukuri.

    PubMed

    Silchenko, Alexandra S; Avilov, Sergey A; Antonov, Alexandr A; Kalinin, Vladimir I; Kalinovsky, Anatoly I; Smirnov, Alexey V; Riguera, Ricardo; Jiménez, Carlos

    2002-12-01

    Five non-sulfated triterpene glycosides, synallactosides A(1) (1), A(2) (2), B(1) (3), B(2) (4), and C (5), have been isolated from the sea cucumber Synallactes nozawai. Their structures have been deduced by extensive analysis of NMR and mass spectra. The glycosides 2-5 are new glycosides. Glycosides 2-4 have carbohydrate chains without precedent in the glycosides from sea cucumbers. This is the first time glycosides are found in members of the family Synallactidae.

  14. Physiological Consequences of Compartmentalized Acyl-CoA Metabolism*

    PubMed Central

    Cooper, Daniel E.; Young, Pamela A.; Klett, Eric L.; Coleman, Rosalind A.

    2015-01-01

    Meeting the complex physiological demands of mammalian life requires strict control of the metabolism of long-chain fatty acyl-CoAs because of the multiplicity of their cellular functions. Acyl-CoAs are substrates for energy production; stored within lipid droplets as triacylglycerol, cholesterol esters, and retinol esters; esterified to form membrane phospholipids; or used to activate transcriptional and signaling pathways. Indirect evidence suggests that acyl-CoAs do not wander freely within cells, but instead, are channeled into specific pathways. In this review, we will discuss the evidence for acyl-CoA compartmentalization, highlight the key modes of acyl-CoA regulation, and diagram potential mechanisms for controlling acyl-CoA partitioning. PMID:26124277

  15. The Balance of Expression of Dihydroflavonol 4-reductase and Flavonol Synthase Regulates Flavonoid Biosynthesis and Red Foliage Coloration in Crabapples.

    PubMed

    Tian, Ji; Han, Zhen-yun; Zhang, Jie; Hu, YuJing; Song, Tingting; Yao, Yuncong

    2015-07-20

    Red leaf color is an attractive trait of Malus families, including crabapple (Malus spp.); however, little is known about the molecular mechanisms that regulate the coloration. Dihydroflavonols are intermediates in the production of both colored anthocyanins and colorless flavonols, and this current study focused on the gene expression balance involved in the relative accumulation of these compounds in crabapple leaves. Levels of anthocyanins and the transcript abundances of the anthocyanin biosynthetic gene, dihydroflavonol 4-reductase (McDFR) and the flavonol biosynthetic gene, flavonol synthase (McFLS), were assessed during the leaf development in two crabapple cultivars, 'Royalty' and 'Flame'. The concentrations of anthocyanins and flavonols correlated with leaf color and we propose that the expression of McDFR and McFLS influences their accumulation. Further studies showed that overexpression of McDFR, or silencing of McFLS, increased anthocyanin production, resulting in red-leaf and red fruit peel phenotypes. Conversely, elevated flavonol production and green phenotypes in crabapple leaves and apple peel were observed when McFLS was overexpressed or McDFR was silenced. These results suggest that the relative activities of McDFR and McFLS are important determinants of the red color of crabapple leaves, via the regulation of the metabolic fate of substrates that these enzymes have in common.

  16. Characterization of a Citrus R2R3-MYB Transcription Factor that Regulates the Flavonol and Hydroxycinnamic Acid Biosynthesis

    PubMed Central

    Liu, Chaoyang; Long, Jianmei; Zhu, Kaijie; Liu, Linlin; Yang, Wei; Zhang, Hongyan; Li, Li; Xu, Qiang; Deng, Xiuxin

    2016-01-01

    Flavonols and hydroxycinnamic acids are important phenylpropanoid metabolites in plants. In this study, we isolated and characterized a citrus R2R3-MYB transcription factor CsMYBF1, encoding a protein belonging to the flavonol-specific MYB subgroup. Ectopic expression of CsMYBF1 in tomato led to an up-regulation of a series of genes involved in primary metabolism and the phenylpropanoid pathway, and induced a strong accumulation of hydroxycinnamic acid compounds but not the flavonols. The RNAi suppression of CsMYBF1 in citrus callus caused a down-regulation of many phenylpropanoid pathway genes and reduced the contents of hydroxycinnamic acids and flavonols. Transactivation assays indicated that CsMYBF1 activated several promoters of phenylpropanoid pathway genes in tomato and citrus. Interestingly, CsMYBF1 could activate the CHS gene promoter in citrus, but not in tomato. Further examinations revealed that the MYBPLANT cis-elements were essential for CsMYBF1 in activating phenylpropanoid pathway genes. In summary, our data indicated that CsMYBF1 possessed the function in controlling the flavonol and hydroxycinnamic acid biosynthesis, and the regulatory differences in the target metabolite accumulation between two species may be due to the differential activation of CHS promoters by CsMYBF1. Therefore, CsMYBF1 constitutes an important gene source for the engineering of specific phenylpropanoid components. PMID:27162196

  17. The Balance of Expression of Dihydroflavonol 4-reductase and Flavonol Synthase Regulates Flavonoid Biosynthesis and Red Foliage Coloration in Crabapples

    PubMed Central

    Tian, Ji; Han, Zhen-yun; Zhang, Jie; Hu, YuJing; Song, Tingting; Yao, Yuncong

    2015-01-01

    Red leaf color is an attractive trait of Malus families, including crabapple (Malus spp.); however, little is known about the molecular mechanisms that regulate the coloration. Dihydroflavonols are intermediates in the production of both colored anthocyanins and colorless flavonols, and this current study focused on the gene expression balance involved in the relative accumulation of these compounds in crabapple leaves. Levels of anthocyanins and the transcript abundances of the anthocyanin biosynthetic gene, dihydroflavonol 4-reductase (McDFR) and the flavonol biosynthetic gene, flavonol synthase (McFLS), were assessed during the leaf development in two crabapple cultivars, ‘Royalty’ and ‘Flame’. The concentrations of anthocyanins and flavonols correlated with leaf color and we propose that the expression of McDFR and McFLS influences their accumulation. Further studies showed that overexpression of McDFR, or silencing of McFLS, increased anthocyanin production, resulting in red-leaf and red fruit peel phenotypes. Conversely, elevated flavonol production and green phenotypes in crabapple leaves and apple peel were observed when McFLS was overexpressed or McDFR was silenced. These results suggest that the relative activities of McDFR and McFLS are important determinants of the red color of crabapple leaves, via the regulation of the metabolic fate of substrates that these enzymes have in common. PMID:26192267

  18. Flavonols modulate the effector functions of healthy individuals' immune complex-stimulated neutrophils: a therapeutic perspective for rheumatoid arthritis.

    PubMed

    Santos, Everton O L; Kabeya, Luciana M; Figueiredo-Rinhel, Andréa S G; Marchi, Larissa F; Andrade, Micássio F; Piatesi, Fabiana; Paoliello-Paschoalato, Adriana B; Azzolini, Ana Elisa C S; Lucisano-Valim, Yara M

    2014-07-01

    Rheumatoid arthritis (RA) patients usually exhibit immune complex (IC) deposition and increased neutrophil activation in the joint. In this study, we assessed how four flavonols (galangin, kaempferol, quercetin, and myricetin) modulate the effector functions of healthy individuals' and active RA patients' IC-stimulated neutrophils. We measured superoxide anion and total reactive oxygen species production using lucigenin (CL-luc)- and luminol (CL-lum)-enhanced chemiluminescence assays, respectively. Galangin, kaempferol, and quercetin inhibited CL-lum to the same degree (mean IC50=2.5 μM). At 2.5 μM, quercetin and galangin suppressed nearly 65% CL-lum of active RA patients' neutrophils. Quercetin inhibited CL-luc the most effectively (IC50=1.71±0.36 μM). The four flavonols diminished myeloperoxidase activity, but they did not decrease NADPH oxidase activity, phagocytosis, microbial killing, or cell viability of neutrophils. The ability of the flavonols to scavenge hypochlorous acid and chloramines, but not H2O2, depended on the hydroxylation degree of the flavonol B-ring. Therefore, at physiologically relevant concentrations, the flavonols partially inhibited the oxidative metabolism of IC-stimulated neutrophils without affecting the other investigated effector functions. Using these compounds to modulate IC-mediated neutrophil activation is a promising safe therapeutic strategy to control inflammation in active RA patients.

  19. Phenylethanoid glycosides and phenolic glycosides from stem bark of Magnolia officinalis.

    PubMed

    Xue, Zhenzhen; Yan, Renyi; Yang, Bin

    2016-07-01

    An investigation of the hydrophilic constituents of the stem bark of Magnolia officinalis was performed and which led to isolation and identification of twenty-one previously unreported glycosides. These included eleven phenylethanoid glycosides, magnolosides F-P, and ten phenolic glycosides, magnolosides Q-Z, along with eight known compounds. Their structures were elucidated on the basis of extensive spectroscopic analyses and chemical hydrolysis methods, as well as by comparison with literature data. Most of the phenylethanoid glycosides contained an allopyranose moiety, which is rare in the plant kingdom. Magnolosides I and K as well as 2-(3,4-dihydroxyphenyl) ethanol 1-O-[4-O-caffeoyl-2-O-α-l-rhamnopyranosyl-3-O-α-l-rhamnopyranosyl-6-O-β-d-glucopyranosyl]-β-d-glucopyranoside showed more potent α-glucosidase inhibitory effects (IC50 values of 0.13, 0.27, and 0.29mM, respectively) than the positive control, acarbose (IC50 value of 1.09mM) in vitro. Magnolosides H, E and D also showed moderate cytotoxicity against MGC-803 and HepG2 cells with IC50 values of 13.59-17.16μM and 29.53-32.46μM, respectively.

  20. A new iridoid glycoside from Scrophularia ningpoensis.

    PubMed

    Niu, Zheng-Rui; Wang, Ru-Feng; Shang, Ming-Ying; Cai, Shao-Qing

    2009-01-01

    A new iridoid glycoside, named 6'-O-cinnamoylharpagide (1), has been isolated from the roots of Scrophularia ningpoensis (Scrophulariaceae) together with nine known compounds, harpagide (2), harpagoside (3), 8-O-feruloylharpagide (4), 8-O-(p-coumaroyl)harpagide (5), 6-O-methylcatalpol (6), aucubin (7), buergerinin B (8), teuhircoside (9) and 6-O-cinnamoyl-D-glucopyranose (10). Compound 10 was obtained as an inseparable mixture of 6-O-cinnamoyl-alpha-D-glucopyranose and 6-O-cinnamoyl-beta-D-glucopyranose at a ratio of 1 : 1, which is presumably formed by cleavage of compound 1. Their structures were elucidated on the basis of chemical and spectral analysis.

  1. Three new triterpene glycosides from Ilex asprella.

    PubMed

    Zhang, Zhen-Xia; Fu, Qiang; Zheng, Ken Yu-Zhong

    2013-01-01

    Three new sulfated triterpene glycosides, asprellanosides C-E (1-3), were isolated from the roots of Ilex asprella. Their structures were elucidated as 3β-[(2-O-sulfo-β-d-xylopyranosyl)oxy]urs-12,19(29)-diene-28-oic acid 28-β-d-glucopyranoside (1), 3β-[(2-O-sulfo-β-d-xylopyranosyl)oxy]urs-12,19-diene-28-oic acid 28-β-d-glucopyranoside (2), and 3β-[(2-O-sulfo-β-d-xylopyranosyl)oxy]urs-12,19-diene-28-oic acid (3) on the basis of the spectral and chemical methods.

  2. Bioavailability of the flavonol quercetin in neonatal calves after oral administration of quercetin aglycone or rutin.

    PubMed

    Maciej, J; Schäff, C T; Kanitz, E; Tuchscherer, A; Bruckmaier, R M; Wolffram, S; Hammon, H M

    2015-06-01

    Polyphenols, such as flavonoids, are secondary plant metabolites with potentially health-promoting properties. In newborn calves flavonoids may improve health status, but little is known about the systemically availability of flavonoids in calves to exert biological effects. The aim of this study was to investigate the oral bioavailability of the flavonol quercetin, applied either as quercetin aglycone (QA) or as its glucorhamnoside rutin (RU), in newborn dairy calves. Twenty-one male newborn German Holstein calves were fed equal amounts of colostrum and milk replacer according to body weight. On d 2 and 29 of life, 9 mg of quercetin equivalents/kg of body weight, either fed as QA or as RU, or no quercetin (control group) were fed together with the morning meal. Blood samples were taken before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 12, 24, and 48 h after feed intake. Quercetin and quercetin metabolites with an intact flavonol structure (isorhamnetin, tamarixetin, and kaempferol) were analyzed in blood plasma after treatment with glucuronidase or sulfatase by HPLC with fluorescence detection. Maximum individual plasma concentration was depicted from the concentration-time-curve on d 2 and 29, respectively. Additional blood samples were taken to measure basal plasma concentrations of total protein, albumin, urea, and lactate as well as pre- and postprandial plasma concentrations of glucose, nonesterified fatty acids, insulin, and cortisol. Plasma concentrations of quercetin and its metabolites were significantly higher on d 2 than on d 29 of life, and administration of QA resulted in higher plasma concentrations of quercetin and its metabolites than RU. The relative bioavailability of total flavonols (sum of quercetin and its metabolites isorhamnetin, tamarixetin, and kaempferol) from RU was 72.5% on d 2 and 49.6% on d 29 when compared with QA (100%). Calves fed QA reached maximum plasma concentrations of total flavonols much earlier than did RU-fed calves. Plasma

  3. A new flavonol glucoside from the aerial parts of Sida glutinosa.

    PubMed

    Das, Niranjan; Achari, Basudev; Harigaya, Yoshihiro; Dinda, Biswanath

    2011-10-01

    Phytochemical investigation on the dried aerial parts of Sida glutinosa has led to the isolation of a new flavonol glucoside, glutinoside (1), along with seven known compounds, 24(28)-dehydromakisterone A (2), 1,2,3,9-tetrahydropyrrolo[2,1-b]-quinazolin-3-amine (3), docosanoic acid, 1-triacontanol, campesterol, stigmasterol, and β-sitosterol. The structures of these compounds were elucidated by means of extensive spectroscopic techniques as well as GC/MS analysis (for sterols) and comparison with the literature data. All these seven known compounds are reported from this plant for the first time.

  4. Enzymatic hydrolysis of steryl ferulates and steryl glycosides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Steryl ferulates and steryl glycosides are phytosterol conjugates found characteristically in cereals. Their properties in enzymatic hydrolysis are, however, not yet well known. Steryl ferulates and steryl glycosides were extracted and purified from rye and wheat bran. Their rates of hydrolysis with...

  5. Evaluating the Cancer Therapeutic Potential of Cardiac Glycosides

    PubMed Central

    Calderón-Montaño, José Manuel; Burgos-Morón, Estefanía; Orta, Manuel Luis; Maldonado-Navas, Dolores; García-Domínguez, Irene; López-Lázaro, Miguel

    2014-01-01

    Cardiac glycosides, also known as cardiotonic steroids, are a group of natural products that share a steroid-like structure with an unsaturated lactone ring and the ability to induce cardiotonic effects mediated by a selective inhibition of the Na+/K+-ATPase. Cardiac glycosides have been used for many years in the treatment of cardiac congestion and some types of cardiac arrhythmias. Recent data suggest that cardiac glycosides may also be useful in the treatment of cancer. These compounds typically inhibit cancer cell proliferation at nanomolar concentrations, and recent high-throughput screenings of drug libraries have therefore identified cardiac glycosides as potent inhibitors of cancer cell growth. Cardiac glycosides can also block tumor growth in rodent models, which further supports the idea that they have potential for cancer therapy. Evidence also suggests, however, that cardiac glycosides may not inhibit cancer cell proliferation selectively and the potent inhibition of tumor growth induced by cardiac glycosides in mice xenografted with human cancer cells is probably an experimental artifact caused by their ability to selectively kill human cells versus rodent cells. This paper reviews such evidence and discusses experimental approaches that could be used to reveal the cancer therapeutic potential of cardiac glycosides in preclinical studies. PMID:24895612

  6. Systematic qualitative and quantitative assessment of anthocyanins, flavones and flavonols in the petals of 108 lotus (Nelumbo nucifera) cultivars.

    PubMed

    Deng, Jiao; Chen, Sha; Yin, Xiaojian; Wang, Kun; Liu, Yanling; Li, Shaohua; Yang, Pingfang

    2013-08-15

    Petal colour is one of the major characteristics that determine the ornamental value of lotus. To assess the contribution of different flavonoids to this character, composition and content of anthocyanins, flavones and flavonols were analysed through high performance liquid chromatography coupled with photodiode array detection tandem electrospray ionisation triple quad mass spectrometry in 108 lotus cultivars with red, pink, yellow, white and red/white pied petal colours. Totally, five anthocyanins and fourteen flavones and flavonols were detected and quantified. In general, the yellow, white and pied species hardly contained any anthocyanins; red cultivars contain more than pink cultivars. Among the five anthocyanins, malvidin 3-O-glucoside was the most abundant one in all the cultivars that contain anthocyanin. The fourteen flavones and flavonols belonged to four groups based on their aglycones. Except for the yellow cultivars, kaempferol-derivatives were the most abundant one. These data might be helpful in lotus breeding for different colours.

  7. Hydrolysis of soybean isoflavonoid glycosides by Dalbergia beta-glucosidases.

    PubMed

    Chuankhayan, Phimonphan; Rimlumduan, Thipwarin; Svasti, Jisnuson; Cairns, James R Ketudat

    2007-03-21

    Two beta-glucosidases from the legumes Dalbergia cochinchinensis and Dalbergia nigrescens were compared for their ability to hydrolyze isoflavonoid glycosides from soybean. Both D. nigrescens and D. cochinchinensis beta-glucosidases could hydrolyze conjugated soybean glycosides, but D. nigrescens beta-glucosidase hydrolyzed both conjugated and nonconjugated glycosides in crude soybean extract more rapidly. The kinetic properties Km, kcat, and kcat/Km of the Dalbergia beta-glucosidases toward conjugated isoflavonoid glycosides, determined using high-performance liquid chromatography, confirmed the higher efficiency of the D. nigrescens beta-glucosidase in hydrolyzing these substrates. The D. nigrescens beta-glucosidase could also efficiently hydrolyze isoflavone glycosides in soy flour suspensions, suggesting its application to increase free isoflavones in soy products.

  8. Ultra(high)-pressure liquid chromatography-electrospray ionization-time-of-flight-ion mobility-high definition mass spectrometry for the rapid identification and structural characterization of flavonoid glycosides from cauliflower waste.

    PubMed

    Gonzales, Gerard Bryan; Raes, Katleen; Coelus, Sofie; Struijs, Karin; Smagghe, Guy; Van Camp, John

    2014-01-03

    In this paper, a strategy for the detection and structural elucidation of flavonoid glycosides from a complex matrix in a single chromatographic run using U(H)PLC-ESI-IMS-HDMS/MS(E) is presented. This system operates using alternative low and high energy voltages that is able to perform the task of conventional MS/MS in a data-independent way without re-injection of the sample, which saves analytical time. Also, ion mobility separation (IMS) was employed as an additional separation technique for compounds that are co-eluting after U(H)PLC separation. First, the fragmentation of flavonoid standards were analyzed and criteria was set for structural elucidation of flavonoids in a plant extract. Based on retention times, UV spectra, exact mass, and MS fragment characteristics, such as abundances of daughter ions and the presence of radical ions ([Y0-H](-)), a total 19 flavonoid glycosides, of which 8 non-acylated and 11 acylated, were detected and structurally characterized in a cauliflower waste extract. Kaempferol and quercetin were the main aglycones detected while sinapic and ferulic acid were the main phenolic acids. C-glycosides were also found although their structure could not be elucidated. The proposed method can be used as a rapid screening test for flavonoid identification and for routine analysis of plant extracts, such as these derived from cauliflower waste. The study also confirms that agroindustrial wastes, such as cauliflower leaves, could be seen as a valuable source of different bioactive phenolic compounds.

  9. Disequilibrium of Flavonol Synthase and Dihydroflavonol-4-Reductase Expression Associated Tightly to White vs. Red Color Flower Formation in Plants

    PubMed Central

    Luo, Ping; Ning, Guogui; Wang, Zhen; Shen, Yuxiao; Jin, Huanan; Li, Penghui; Huang, Shasha; Zhao, Jian; Bao, Manzhu

    2016-01-01

    Flower color is the main character throughout the plant kingdom. Though substantial information exists regarding the structural and regulatory genes involved in anthocyanin and flavonol biosynthesis, little is known that what make a diverse white vs. red color flower in natural species. Here, the contents of pigments in seven species from varied phylogenetic location in plants with red and white flowers were determined. Flavonols could be detected in red and white flowers, but anthocyanins were almost undetectable in the white cultivar. Comparisons of expression patterns of gene related to the flavonoid biosynthesis indicated that disequilibrium expression of flavonol synthase (FLS) and dihydroflavonol-4-reductase (DFR) genes determined the accumulation of flavonols and anothcyanins in both red and white flowers of seven species. To further investigate the role of such common regulatory patterns in determining flower color, FLS genes were isolated from Rosa rugosa (RrFLS1), Prunus persica (PpFLS), and Petunia hybrida (PhFLS), and DFR genes were isolated from Rosa rugosa (RrDFR1) and Petunia hybrida (PhDFR). Heterologous expression of the FLS genes within tobacco host plants demonstrated conservation of function, with the transgenes promoting flavonol biosynthesis and inhibiting anthocyanin accumulation, so resulting in white flowers. Conversely, overexpression of DFR genes in tobacco displayed down-regulation of the endogenous NtFLS gene, and the promotion of anthocyanin synthesis. On this basis, we propose a model in which FLS and DFR gene-products compete for common substrates in order to direct the biosynthesis of flavonols and anthocyanins, respectively, thereby determining white vs. red coloration of flowers. PMID:26793227

  10. Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed.

    PubMed

    Cahoon, E B; Coughlan, S J; Shanklin, J

    1997-04-01

    A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1delta9)* and cis-vaccenic (18:1delta11) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed delta9 desaturation of acyl-ACP substrates, and the recombinant enzyme exhibited seven- to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known delta9-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized delta9-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of a delta9-18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities.

  11. Acyl-acyl carrier protein as a source of fatty acids for bacterial bioluminescence

    SciTech Connect

    Byers, D.M.; Meighen, E.A.

    1985-09-01

    Pulse-chase experiments with (/sup 3/H)tetradecanoic acid and ATP showed that the bioluminescence-related 32-kDa acyltransferase from Vibrio harveyi can specifically catalyze the deacylation of a /sup 3/H-labeled 18-kDa protein observed in extracts of this bacterium. The 18-kDa protein has been partially purified and its physical and chemical properties strongly indicate that it is fatty acyl-acyl carrier protein (acyl-ACP). Both this V. harveyi (/sup 3/H)acylprotein and (/sup 3/H)palmitoyl-ACP from Escherichia coli were substrates in vitro for either the V. harveyi 32-kDa acyltransferase or the analogous enzyme (34K) from Photobacterium phosphoreum. TLC analysis indicated that the hexane-soluble product of the reaction is fatty acid. No significant cleavage of either E. coli or V. harveyi tetradecanoyl-ACP was observed in extracts of these bacteria unless the 32-kDa or 34K acyltransferase was present. Since these enzymes are believed to be responsible for the supply of fatty acids for reduction to form the aldehyde substrate of luciferase, the above results suggest that long-chain acyl-ACP is the source of fatty acids for bioluminescence.

  12. Accumulation of Flavonols over Hydroxycinnamic Acids Favors Oxidative Damage Protection under Abiotic Stress

    PubMed Central

    Martinez, Vicente; Mestre, Teresa C.; Rubio, Francisco; Girones-Vilaplana, Amadeo; Moreno, Diego A.; Mittler, Ron; Rivero, Rosa M.

    2016-01-01

    Efficient detoxification of reactive oxygen species (ROS) is thought to play a key role in enhancing the tolerance of plants to abiotic stresses. Although multiple pathways, enzymes, and antioxidants are present in plants, their exact roles during different stress responses remain unclear. Here, we report on the characterization of the different antioxidant mechanisms of tomato plants subjected to heat stress, salinity stress, or a combination of both stresses. All the treatments applied induced an increase of oxidative stress, with the salinity treatment being the most aggressive, resulting in plants with the lowest biomass, and the highest levels of H2O2 accumulation, lipid peroxidation, and protein oxidation. However, the results obtained from the transcript expression study and enzymatic activities related to the ascorbate-glutathione pathway did not fully explain the differences in the oxidative damage observed between salinity and the combination of salinity and heat. An exhaustive metabolomics study revealed the differential accumulation of phenolic compounds depending on the type of abiotic stress applied. An analysis at gene and enzyme levels of the phenylpropanoid metabolism concluded that under conditions where flavonols accumulated to a greater degree as compared to hydroxycinnamic acids, the oxidative damage was lower, highlighting the importance of flavonols as powerful antioxidants, and their role in abiotic stress tolerance. PMID:27379130

  13. Competition between anthocyanin and flavonol biosynthesis produces spatial pattern variation of floral pigments between Mimulus species.

    PubMed

    Yuan, Yao-Wu; Rebocho, Alexandra B; Sagawa, Janelle M; Stanley, Lauren E; Bradshaw, Harvey D

    2016-03-01

    Flower color patterns have long served as a model for developmental genetics because pigment phenotypes are visually striking, yet generally not required for plant viability, facilitating the genetic analysis of color and pattern mutants. The evolution of novel flower colors and patterns has played a key role in the adaptive radiation of flowering plants via their specialized interactions with different pollinator guilds (e.g., bees, butterflies, birds), motivating the search for allelic differences affecting flower color pattern in closely related plant species with different pollinators. We have identified LIGHT AREAS1 (LAR1), encoding an R2R3-MYB transcription factor, as the causal gene underlying the spatial pattern variation of floral anthocyanin pigmentation between two sister species of monkeyflower: the bumblebee-pollinated Mimulus lewisii and the hummingbird-pollinated Mimulus cardinalis. We demonstrated that LAR1 positively regulates FLAVONOL SYNTHASE (FLS), essentially eliminating anthocyanin biosynthesis in the white region (i.e., light areas) around the corolla throat of M. lewisii flowers by diverting dihydroflavonol into flavonol biosynthesis from the anthocyanin pigment pathway. FLS is preferentially expressed in the light areas of the M. lewisii flower, thus prepatterning the corolla. LAR1 expression in M. cardinalis flowers is much lower than in M. lewisii, explaining the unpatterned phenotype and recessive inheritance of the M. cardinalis allele. Furthermore, our gene-expression analysis and genetic mapping results suggest that cis-regulatory change at the LAR1 gene played a critical role in the evolution of different pigmentation patterns between the two species.

  14. Effect of flavonols on wine astringency and their interaction with human saliva.

    PubMed

    Ferrer-Gallego, Raúl; Brás, Natércia F; García-Estévez, Ignacio; Mateus, Nuno; Rivas-Gonzalo, Julián C; de Freitas, Victor; Escribano-Bailón, M Teresa

    2016-10-15

    The addition of external phenolic compounds to wines in order to improve their sensory quality is an established winemaking practice. This study was aimed at evaluating the effect of the addition of quercetin 3-O-glucoside on the astringency and bitterness of wines. Sensory results showed that the addition of this flavonol to wines results in an increase in astringency and bitterness. Additionally, flavonol-human salivary protein interactions were studied using fluorescence spectroscopy, dynamic light scattering and molecular dynamic simulations (MD). The apparent Stern-Volmer (KsvApp) and the apparent bimolecular quenching constants (kqApp) were calculated from fluorescence spectra. The KsvApp was 12620±390M(-1), and the apparent biomolecular constant was 3.94×10(12)M(-1)s(-1), which suggests that a complex was formed between the human salivary proteins and quercetin 3-O-glucoside. MD simulations showed that the quercetin 3-O-glucoside molecules have the ability to bind to the IB937 model peptide.

  15. Accumulation of Flavonols over Hydroxycinnamic Acids Favors Oxidative Damage Protection under Abiotic Stress.

    PubMed

    Martinez, Vicente; Mestre, Teresa C; Rubio, Francisco; Girones-Vilaplana, Amadeo; Moreno, Diego A; Mittler, Ron; Rivero, Rosa M

    2016-01-01

    Efficient detoxification of reactive oxygen species (ROS) is thought to play a key role in enhancing the tolerance of plants to abiotic stresses. Although multiple pathways, enzymes, and antioxidants are present in plants, their exact roles during different stress responses remain unclear. Here, we report on the characterization of the different antioxidant mechanisms of tomato plants subjected to heat stress, salinity stress, or a combination of both stresses. All the treatments applied induced an increase of oxidative stress, with the salinity treatment being the most aggressive, resulting in plants with the lowest biomass, and the highest levels of H2O2 accumulation, lipid peroxidation, and protein oxidation. However, the results obtained from the transcript expression study and enzymatic activities related to the ascorbate-glutathione pathway did not fully explain the differences in the oxidative damage observed between salinity and the combination of salinity and heat. An exhaustive metabolomics study revealed the differential accumulation of phenolic compounds depending on the type of abiotic stress applied. An analysis at gene and enzyme levels of the phenylpropanoid metabolism concluded that under conditions where flavonols accumulated to a greater degree as compared to hydroxycinnamic acids, the oxidative damage was lower, highlighting the importance of flavonols as powerful antioxidants, and their role in abiotic stress tolerance.

  16. Inhibition of Klebsiella pneumoniae DnaB helicase by the flavonol galangin.

    PubMed

    Chen, Cheng-Chieh; Huang, Cheng-Yang

    2011-01-01

    Klebsiella pneumoniae is a ubiquitous opportunistic pathogen that colonizes at the mucosal surfaces in humans and causes severe diseases. Many clinical strains of K. pneumoniae are highly resistant to antibiotics. Here, we used fluorescence quenching to show that the flavonols galangin, myricetin, quercetin, and kaempferol, bearing different numbers of hydroxyl substituent on the aromatic rings, may inhibit dNTP binding of the primary replicative DnaB helicase of K. pneumoniae (KpDnaB), an essential component of the cellular replication machinery critical for bacterial survival. The binding affinity of KpDnaB to dNTPs varies in the following order: dCTP ~ dGTP > dTTP > dATP. Addition of 10 μM galangin significantly decreased the binding ability of KpDnaB to dATP, whereas the binding affinity of KpDnaB to dGTP that was almost unaffected. Our analyses suggest that these flavonol compounds may be used in the development of new antibiotics that target K. pneumoniae and other bacteria.

  17. Molecular imprinted polymer for solid-phase extraction of flavonol aglycones from Moringa oleifera extracts.

    PubMed

    Pakade, Vusumzi; Cukrowska, Ewa; Lindahl, Sofia; Turner, Charlotta; Chimuka, Luke

    2013-02-01

    Molecular imprinted polymer produced using quercetin as the imprinting compound was applied for the extraction of flavonol aglycones (quercetin and kaempferol) from Moringa oleifera methanolic extracts obtained using heated reflux extraction method. Identification and quantification of these flavonols in the Moringa extracts was achieved using high performance liquid chromatography with ultra violet detection. Breakthrough volume and retention capacity of molecular imprinted polymer SPE was investigated using a mixture of myricetin, quercetin and kaempferol. The calculated theoretical number of plates was found to be 14, 50 and 8 for myricetin, quercetin and kaempferol, respectively. Calculated adsorption capacities were 2.0, 3.4 and 3.7 μmol/g for myricetin, quercetin and kaempferol, respectively. No myricetin was observed in Moringa methanol extracts. Recoveries of quercetin and kaempferol from Moringa methanol extracts of leaves and flowers ranged from 77 to 85% and 75 to 86%, respectively, demonstrating the feasibility of using the developed molecularly imprinted SPE method for quantitative clean-up of both of these flavonoids. Using heated reflux extraction combined with molecularly imprinted SPE, quercetin concentrations of 975 ± 58 and 845 ± 32 mg/kg were determined in Moringa leaves and flowers, respectively. However, the concentrations of kaempferol found in leaves and flowers were 2100 ± 176 and 2802 ± 157 mg/kg, respectively.

  18. Absorption of flavonols derived from sea buckthorn (Hippophaë rhamnoides L.) and their effect on emerging risk factors for cardiovascular disease in humans.

    PubMed

    Suomela, Jukka-Pekka; Ahotupa, Markku; Yang, Baoru; Vasankari, Tommi; Kallio, Heikki

    2006-09-20

    Sea buckthorn (Hippophaë rhamnoides L.) is a rich source of flavonols, especially isorhamnetin. Most prospective cohort studies have indicated some degree of inverse association between flavonoid intake and coronary heart disease. Animal and human studies suggest that sea buckthorn flavonoids may scavenge free radicals, lower blood viscosity, and enhance cardiac function. The effects of flavonol aglycones derived from sea buckthorn on the risk factors of cardiovascular disease as well as their absorption were studied in humans. The flavonols, ingested with oatmeal porridge, did not have a significant effect on the levels of oxidized low-density lipoprotein, C-reactive protein, and homocysteine, on the plasma antioxidant potential, or on the paraoxonase activity. Flavonols at two dosages in oatmeal porridge were rapidly absorbed, and a relatively small amount of sea buckthorn oil added to the porridge seemed to have increased the bioavailability of sea buckthorn flavonols consumed at the higher dose.

  19. ALA-Induced Flavonols Accumulation in Guard Cells Is Involved in Scavenging H2O2 and Inhibiting Stomatal Closure in Arabidopsis Cotyledons

    PubMed Central

    An, Yuyan; Feng, Xinxin; Liu, Longbo; Xiong, Lijun; Wang, Liangju

    2016-01-01

    5-aminolevulinic acid (ALA), a new plant growth regulator, can inhibit stomatal closure by reducing H2O2 accumulation in guard cells. Flavonols are a main kind of flavonoids and have been proposed as H2O2 scavengers in guard cells. 5-aminolevulinic acid can significantly improve flavonoids accumulation in plants. However, whether ALA increases flavonols content in guard cells and the role of flavonols in ALA-regulated stomatal movement remains unclear. In this study, we first demonstrated that ALA pretreatment inhibited ABA-induced stomatal closure by reducing H2O2 accumulation in guard cells of Arabidopsis seedlings. This result confirms the inhibitory effect of ALA on stomatal closure and the important role of decreased H2O2 accumulation in this process. We also found that ALA significantly improved flavonols accumulation in guard cells using a flavonol-specific dye. Furthermore, using exogenous quercetin and kaempferol, two major components of flavonols in Arabidopsis leaves, we showed that flavonols accumulation inhibited ABA-induced stomatal movement by suppressing H2O2 in guard cells. Finally, we showed that the inhibitory effect of ALA on ABA-induced stomatal closure was largely impaired in flavonoid-deficient transparent testa4 (tt4) mutant. In addition, exogenous flavonols recovered stomatal responses of tt4 to the wild-type levels. Taken together, we conclude that ALA-induced flavonol accumulation in guard cells is partially involved in the inhibitory effect of ALA on ABA-induced H2O2 accumulation and stomatal closure. Our data provide direct evidence that ALA can regulate stomatal movement by improving flavonols accumulation, revealing new insights into guard cell signaling. PMID:27895660

  20. Progress toward Understanding Protein S-acylation: Prospective in Plants.

    PubMed

    Li, Yaxiao; Qi, Baoxiu

    2017-01-01

    S-acylation, also known as S-palmitoylation or palmitoylation, is a reversible post-translational lipid modification in which long chain fatty acid, usually the 16-carbon palmitate, covalently attaches to a cysteine residue(s) throughout the protein via a thioester bond. It is involved in an array of important biological processes during growth and development, reproduction and stress responses in plant. S-acylation is a ubiquitous mechanism in eukaryotes catalyzed by a family of enzymes called Protein S-Acyl Transferases (PATs). Since the discovery of the first PAT in yeast in 2002 research in S-acylation has accelerated in the mammalian system and followed by in plant. However, it is still a difficult field to study due to the large number of PATs and even larger number of putative S-acylated substrate proteins they modify in each genome. This is coupled with drawbacks in the techniques used to study S-acylation, leading to the slower progress in this field compared to protein phosphorylation, for example. In this review we will summarize the discoveries made so far based on knowledge learnt from the characterization of protein S-acyltransferases and the S-acylated proteins, the interaction mechanisms between PAT and its specific substrate protein(s) in yeast and mammals. Research in protein S-acylation and PATs in plants will also be covered although this area is currently less well studied in yeast and mammalian systems.

  1. Progress toward Understanding Protein S-acylation: Prospective in Plants

    PubMed Central

    Li, Yaxiao; Qi, Baoxiu

    2017-01-01

    S-acylation, also known as S-palmitoylation or palmitoylation, is a reversible post-translational lipid modification in which long chain fatty acid, usually the 16-carbon palmitate, covalently attaches to a cysteine residue(s) throughout the protein via a thioester bond. It is involved in an array of important biological processes during growth and development, reproduction and stress responses in plant. S-acylation is a ubiquitous mechanism in eukaryotes catalyzed by a family of enzymes called Protein S-Acyl Transferases (PATs). Since the discovery of the first PAT in yeast in 2002 research in S-acylation has accelerated in the mammalian system and followed by in plant. However, it is still a difficult field to study due to the large number of PATs and even larger number of putative S-acylated substrate proteins they modify in each genome. This is coupled with drawbacks in the techniques used to study S-acylation, leading to the slower progress in this field compared to protein phosphorylation, for example. In this review we will summarize the discoveries made so far based on knowledge learnt from the characterization of protein S-acyltransferases and the S-acylated proteins, the interaction mechanisms between PAT and its specific substrate protein(s) in yeast and mammals. Research in protein S-acylation and PATs in plants will also be covered although this area is currently less well studied in yeast and mammalian systems. PMID:28392791

  2. Understanding Acyl Chain and Glycerolipid Metabolism in Plants

    SciTech Connect

    Ohlrogge, John B.

    2013-11-05

    Progress is reported in these areas: acyl-editing in initial eukaryotic lipid assembly in soybean seeds; identification and characterization of two Arabidopsis thaliana lysophosphatidyl acyltransferases with preference for lysophosphatidylethanolamine; and characterization and subcellular distribution of lysolipid acyl transferase activity of pea leaves.

  3. Characterization of the "Escherichia Coli" Acyl Carrier Protein Phosphodiesterase

    ERIC Educational Resources Information Center

    Thomas, Jacob

    2009-01-01

    Acyl carrier protein (ACP) is a small essential protein that functions as a carrier of the acyl intermediates of fatty acid synthesis. ACP requires the posttranslational attachment of a 4'phosphopantetheine functional group, derived from CoA, in order to perform its metabolic function. A Mn[superscript 2+] dependent enzymatic activity that removes…

  4. Acyl peptidic siderophores: structures, biosyntheses and post-assembly modifications.

    PubMed

    Kem, Michelle P; Butler, Alison

    2015-06-01

    Acyl peptidic siderophores are produced by a variety of bacteria and possess unique amphiphilic properties. Amphiphilic siderophores are generally produced in a suite where the iron(III)-binding headgroup remains constant while the fatty acid appendage varies by length and functionality. Acyl peptidic siderophores are commonly synthesized by non-ribosomal peptide synthetases; however, the method of peptide acylation during biosynthesis can vary between siderophores. Following biosynthesis, acyl siderophores can be further modified enzymatically to produce a more hydrophilic compound, which retains its ferric chelating abilities as demonstrated by pyoverdine from Pseudomonas aeruginosa and the marinobactins from certain Marinobacter species. Siderophore hydrophobicity can also be altered through photolysis of the ferric complex of certain β-hydroxyaspartic acid-containing acyl peptidic siderophores.

  5. Effects of tripterygium glycosides on restenosis following endovascular treatment

    PubMed Central

    HAN, BING; GE, CHANG-QING; ZHANG, HONG-GUANG; ZHOU, CHEN-GUANG; JI, GUO-HUI; YANG, ZHENG; ZHANG, LIANG

    2016-01-01

    The mechanism and associated factors of restenosis following intravascular stent implantation remain to be elucidated. The present two-part experimental and clinical study aimed to investigate the effects of tripterygium glycosides on in-stent restenosis subsequent to intra-arterial therapy. Following endovascular stent implantation in rabbit iliac arteries, post-stent outcomes were evaluated in cyclosporine groups, low-dose and high-dose tripterygium glycosides groups and controls. Post-operative angiography indicated that vessel diameters were similar between groups; however, at 28 days after receiving the therapeutic agents, vessels of the cyclosporine and tripterygium glycosides groups were significantly larger than those of the controls. Furthermore, three groups of patients had comparable baseline levels of interleukin (IL)-10, IL-18 and C-reactive protein, and intima-media thickness. However, 1 month after stent implantation, levels of IL-10 and IL-18 were markedly reduced in the high- and low-dose tripterygium glycosides groups compared with controls. At 6 months after surgery, the stent patency rate in patients with bare stents was significantly lower than in patients receiving tripterygium glycosides (P≤0.009). In addition, the ankle-brachial index was also higher than in those without tripterygium glycosides (P<0.001). Results of the experimental and clinical studies suggest that tripterygium glycosides may inhibit and possibly aid in the prevention of in-stent restenosis formation following endovascular treatment of lower-extremity artery disease. PMID:27108914

  6. Steviol glycoside safety: are highly purified steviol glycoside sweeteners food allergens?

    PubMed

    Urban, Jonathan D; Carakostas, Michael C; Taylor, Steve L

    2015-01-01

    Steviol glycoside sweeteners are extracted from the plant Stevia rebaudiana (Bertoni), a member of the Asteraceae (Compositae) family. Many plants from this family can induce hypersensitivity reactions via multiple routes of exposure (e.g., ragweed, goldenrod, chrysanthemum, echinacea, chamomile, lettuce, sunflower and chicory). Based on this common taxonomy, some popular media reports and resources have issued food warnings alleging the potential for stevia allergy. To determine if such allergy warnings are warranted on stevia-based sweeteners, a comprehensive literature search was conducted to identify all available data related to allergic responses following the consumption of stevia extracts or highly purified steviol glycosides. Hypersensitivity reactions to stevia in any form are rare. The few cases documented in the peer-reviewed literature were reported prior to the introduction of high-purity products to the market in 2008 when many global regulatory authorities began to affirm the safety of steviol glycosides. Neither stevia manufacturers nor food allergy networks have reported significant numbers of any adverse events related to ingestion of stevia-based sweeteners, and there have been no reports of stevia-related allergy in the literature since 2008. Therefore, there is little substantiated scientific evidence to support warning statements to consumers about allergy to highly purified stevia extracts.

  7. Acyl-CoA binding proteins: multiplicity and function.

    PubMed

    Gossett, R E; Frolov, A A; Roths, J B; Behnke, W D; Kier, A B; Schroeder, F

    1996-09-01

    The physiological role of long-chain fatty acyl-CoA is thought to be primarily in intermediary metabolism of fatty acids. However, recent data show that nM to microM levels of these lipophilic molecules are potent regulators of cell functions in vitro. Although long-chain fatty acyl-CoA are present at several hundred microM concentration in the cell, very little long-chain fatty acyl-CoA actually exists as free or unbound molecules, but rather is bound with high affinity to membrane lipids and/or proteins. Recently, there is growing awareness that cytosol contains nonenzymatic proteins also capable of binding long-chain fatty acyl-CoA with high affinity. Although the identity of the cytosolic long-chain fatty acyl-CoA binding protein(s) has been the subject of some controversy, there is growing evidence that several diverse nonenzymatic cytosolic proteins will bind long-chain fatty acyl-CoA. Not only does acyl-CoA binding protein specifically bind medium and long-chain fatty acyl-CoA (LCFA-CoA), but ubiquitous proteins with multiple ligand specificities such as the fatty acid binding proteins and sterol carrier protein-2 also bind LCFA-CoA with high affinity. The potential of these acyl-CoA binding proteins to influence the level of free LCFA-CoA and thereby the amount of LCFA-CoA bound to regulatory sites in proteins and enzymes is only now being examined in detail. The purpose of this article is to explore the identity, nature, function, and pathobiology of these fascinating newly discovered long-chain fatty acyl-CoA binding proteins. The relative contributions of these three different protein families to LCFA-CoA utilization and/or regulation of cellular activities are the focus of new directions in this field.

  8. Cysteine-286 as the site of acylation of the Lux-specific fatty acyl-CoA reductase.

    PubMed

    Lee, C Y; Meighen, E A

    1997-04-04

    The channelling of fatty acids into the fatty aldehyde substrate for the bacterial bioluminescence reaction is catalyzed by a fatty acid reductase multienzyme complex, which channels fatty acids through the thioesterase (LuxD), synthetase (LuxE) and reductase (LuxC) components. Although all three components can be readily acylated in extracts of different luminescent bacteria, this complex has been successfully purified only from Photobacterium phosphoreum and the sites of acylation identified on LuxD and LuxE. To identify the acylation site on LuxC, the nucleotide sequence of P. phosphoreum luxC has been determined and the gene expressed in a mutant Escherichia coli strain. Even in crude extracts, the acylated reductase intermediate as well as acyl-CoA reductase activity could be readily detected, providing the basis for analysis of mutant reductases. Comparison of the amino-acid sequences of LuxC from P. phosphoreum, P. leiognathi and other luminescent bacteria, showed that only three cysteine residues (C171, C279, and C286) were conserved. As a cysteine residue on LuxC has been implicated in fatty acyl transfer, each of the conserved cysteine residues of the P. phosphoreum and P. leiognathi reductases was converted to a serine residue, and the properties of the mutant proteins examined. Only mutation of C286-blocked reductase activity and prevented formation of the acylated reductase intermediate, showing that C286 is the site of acylation on LuxC.

  9. Glycoside Hydrolases across Environmental Microbial Communities

    PubMed Central

    Berlemont, Renaud

    2016-01-01

    Across many environments microbial glycoside hydrolases support the enzymatic processing of carbohydrates, a critical function in many ecosystems. Little is known about how the microbial composition of a community and the potential for carbohydrate processing relate to each other. Here, using 1,934 metagenomic datasets, we linked changes in community composition to variation of potential for carbohydrate processing across environments. We were able to show that each ecosystem-type displays a specific potential for carbohydrate utilization. Most of this potential was associated with just 77 bacterial genera. The GH content in bacterial genera is best described by their taxonomic affiliation. Across metagenomes, fluctuations of the microbial community structure and GH potential for carbohydrate utilization were correlated. Our analysis reveals that both deterministic and stochastic processes contribute to the assembly of complex microbial communities. PMID:27992426

  10. Synthesis and sensory evaluation of ent-kaurane diterpene glycosides.

    PubMed

    Prakash, Indra; Campbell, Mary; San Miguel, Rafael Ignacio; Chaturvedula, Venkata Sai Prakash

    2012-07-26

    Catalytic hydrogenation of the three ent-kaurane diterpene glycosides isolated from Stevia rebaudiana, namely rubusoside, stevioside, and rebaudioside-A has been carried out using Pd(OH)₂ and their corresponding dihydro derivatives have been isolated as the products. Synthesis of reduced steviol glycosides was performed using straightforward chemistry and their structures were characterized on the basis of 1D and 2D NMR spectral data and chemical studies. Also, we report herewith the sensory evaluation of all the reduced compounds against their corresponding original steviol glycosides and sucrose for the sweetness property of these molecules.

  11. A Novel Glucosylation Reaction on Anthocyanins Catalyzed by Acyl-Glucose–Dependent Glucosyltransferase in the Petals of Carnation and Delphinium[C][W

    PubMed Central

    Matsuba, Yuki; Sasaki, Nobuhiro; Tera, Masayuki; Okamura, Masachika; Abe, Yutaka; Okamoto, Emi; Nakamura, Haruka; Funabashi, Hisakage; Takatsu, Makoto; Saito, Mikako; Matsuoka, Hideaki; Nagasawa, Kazuo; Ozeki, Yoshihiro

    2010-01-01

    Glucosylation of anthocyanin in carnations (Dianthus caryophyllus) and delphiniums (Delphinium grandiflorum) involves novel sugar donors, aromatic acyl-glucoses, in a reaction catalyzed by the enzymes acyl-glucose–dependent anthocyanin 5(7)-O-glucosyltransferase (AA5GT and AA7GT). The AA5GT enzyme was purified from carnation petals, and cDNAs encoding carnation Dc AA5GT and the delphinium homolog Dg AA7GT were isolated. Recombinant Dc AA5GT and Dg AA7GT proteins showed AA5GT and AA7GT activities in vitro. Although expression of Dc AA5GT in developing carnation petals was highest at early stages, AA5GT activity and anthocyanin accumulation continued to increase during later stages. Neither Dc AA5GT expression nor AA5GT activity was observed in the petals of mutant carnations; these petals accumulated anthocyanin lacking the glucosyl moiety at the 5 position. Transient expression of Dc AA5GT in petal cells of mutant carnations is expected to result in the transfer of a glucose moiety to the 5 position of anthocyanin. The amino acid sequences of Dc AA5GT and Dg AA7GT showed high similarity to glycoside hydrolase family 1 proteins, which typically act as β-glycosidases. A phylogenetic analysis of the amino acid sequences suggested that other plant species are likely to have similar acyl-glucose–dependent glucosyltransferases. PMID:20971893

  12. Transcription factor WRKY23 assists auxin distribution patterns during Arabidopsis root development through local control on flavonol biosynthesis.

    PubMed

    Grunewald, Wim; De Smet, Ive; Lewis, Daniel R; Löfke, Christian; Jansen, Leentje; Goeminne, Geert; Vanden Bossche, Robin; Karimi, Mansour; De Rybel, Bert; Vanholme, Bartel; Teichmann, Thomas; Boerjan, Wout; Van Montagu, Marc C E; Gheysen, Godelieve; Muday, Gloria K; Friml, Jirí; Beeckman, Tom

    2012-01-31

    Gradients of the plant hormone auxin, which depend on its active intercellular transport, are crucial for the maintenance of root meristematic activity. This directional transport is largely orchestrated by a complex interaction of specific influx and efflux carriers that mediate the auxin flow into and out of cells, respectively. Besides these transport proteins, plant-specific polyphenolic compounds known as flavonols have been shown to act as endogenous regulators of auxin transport. However, only limited information is available on how flavonol synthesis is developmentally regulated. Using reduction-of-function and overexpression approaches in parallel, we demonstrate that the WRKY23 transcription factor is needed for proper root growth and development by stimulating the local biosynthesis of flavonols. The expression of WRKY23 itself is controlled by auxin through the Auxin Response Factor 7 (ARF7) and ARF19 transcriptional response pathway. Our results suggest a model in which WRKY23 is part of a transcriptional feedback loop of auxin on its own transport through local regulation of flavonol biosynthesis.

  13. Flavonol content, oil %, and fatty acid composition variability in seeds of Teramnus labialis and T. uncinatus accessions with nutraceutical potential

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Teramnus labialis and T. uncinatus are both underutilized legume species. Teramnus labialis is used as food in India while T. uncinatus has potential use in pasture mixes. Photoperiod-sensitive Teramnus accessions were grown in the greenhouse from 2010 to 2011 and evaluated for flavonol content, oil...

  14. Calyx diversity of flavonols and fatty acids in Roselle (Hibiscus sabdariffa) for use as a potential nutraceutical crop.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavonols and fatty acids in plants has potential to be used as an antioxidant, lowering of cholesterol, and for cancer prevention. Roselle is a photoperiod and frost-sensitive species requiring greenhouse production in the Griffin, GA environment. Six accessions of roselle calyces were evaluated fo...

  15. Cardiac glycosides and pregnanes from Adenium obesum (studies on the constituents of Adenium. I).

    PubMed

    Yamauchi, T; Abe, F

    1990-03-01

    Cardiac glycosides and pregnanes from the roots and the stems of Adenium obesum Roem. et Schult. were investigated. Among 30 cardiac glycosides including 15 known glycosides and 15 new combinations of the known aglycones and sugars, the structures of 11 glycosides were elucidated. Oleandrigenin beta-gentiobiosyl-beta-D-thevetoside was the main glycoside. Neridienone A and 16,17-dihydroneridienone A, common pregnanes in Apocynaceae, were also isolated.

  16. Expression of Genes Involved in Anthocyanin Biosynthesis in Relation to Anthocyanin, Proanthocyanidin, and Flavonol Levels during Bilberry Fruit Development1

    PubMed Central

    Jaakola, Laura; Määttä, Kaisu; Pirttilä, Anna Maria; Törrönen, Riitta; Kärenlampi, Sirpa; Hohtola, Anja

    2002-01-01

    The production of anthocyanins in fruit tissues is highly controlled at the developmental level. We have studied the expression of flavonoid biosynthesis genes during the development of bilberry (Vaccinium myrtillus) fruit in relation to the accumulation of anthocyanins, proanthocyanidins, and flavonols in wild berries and in color mutants of bilberry. The cDNA fragments of five genes from the flavonoid pathway, phenylalanine ammonia-lyase, chalcone synthase, flavanone 3-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase, were isolated from bilberry using the polymerase chain reaction technique, sequenced, and labeled with a digoxigenin-dUTP label. These homologous probes were used for determining the expression of the flavonoid pathway genes in bilberries. The contents of anthocyanins, proanthocyanidins, and flavonols in ripening bilberries were analyzed with high-performance liquid chromatography-diode array detector and were identified using a mass spectrometry interface. Our results demonstrate a correlation between anthocyanin accumulation and expression of the flavonoid pathway genes during the ripening of berries. At the early stages of berry development, procyanidins and quercetin were the major flavonoids, but the levels decreased dramatically during the progress of ripening. During the later stages of ripening, the content of anthocyanins increased strongly and they were the major flavonoids in the ripe berry. The expression of flavonoid pathway genes in the color mutants of bilberry was reduced. A connection between flavonol and anthocyanin synthesis in bilberry was detected in this study and also in previous data collected from flavonol and anthocyanin analyses from other fruits. In accordance with this, models for the connection between flavonol and anthocyanin syntheses in fruit tissues are presented. PMID:12376640

  17. Expression of genes involved in anthocyanin biosynthesis in relation to anthocyanin, proanthocyanidin, and flavonol levels during bilberry fruit development.

    PubMed

    Jaakola, Laura; Määttä, Kaisu; Pirttilä, Anna Maria; Törrönen, Riitta; Kärenlampi, Sirpa; Hohtola, Anja

    2002-10-01

    The production of anthocyanins in fruit tissues is highly controlled at the developmental level. We have studied the expression of flavonoid biosynthesis genes during the development of bilberry (Vaccinium myrtillus) fruit in relation to the accumulation of anthocyanins, proanthocyanidins, and flavonols in wild berries and in color mutants of bilberry. The cDNA fragments of five genes from the flavonoid pathway, phenylalanine ammonia-lyase, chalcone synthase, flavanone 3-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase, were isolated from bilberry using the polymerase chain reaction technique, sequenced, and labeled with a digoxigenin-dUTP label. These homologous probes were used for determining the expression of the flavonoid pathway genes in bilberries. The contents of anthocyanins, proanthocyanidins, and flavonols in ripening bilberries were analyzed with high-performance liquid chromatography-diode array detector and were identified using a mass spectrometry interface. Our results demonstrate a correlation between anthocyanin accumulation and expression of the flavonoid pathway genes during the ripening of berries. At the early stages of berry development, procyanidins and quercetin were the major flavonoids, but the levels decreased dramatically during the progress of ripening. During the later stages of ripening, the content of anthocyanins increased strongly and they were the major flavonoids in the ripe berry. The expression of flavonoid pathway genes in the color mutants of bilberry was reduced. A connection between flavonol and anthocyanin synthesis in bilberry was detected in this study and also in previous data collected from flavonol and anthocyanin analyses from other fruits. In accordance with this, models for the connection between flavonol and anthocyanin syntheses in fruit tissues are presented.

  18. Chrysophanol glycosides from callus cultures of monocotyledonous Kniphofia spp. (Asphodelaceae).

    PubMed

    Ito, Hideyuki; Nishida, Yasuko; Yamazaki, Mie; Nakahara, Keisuke; Michalska-Hartwich, Malgorzata; Furmanowa, Miroslawa; Leistner, Eckhard; Yoshida, Takashi

    2004-10-01

    We established callus cultures of the monocotyledonous plants Kniphofia foliosa and K. tuckii (Asphodelaceae), which produce the anthraquinone derivatives chrysophanol and its glycosides. The minor product chrysophanol 8-O-beta-gentiobioside was fully characterized by spectroscopic analysis and synthesis.

  19. A flavonol triglycoside and investigation of the antioxidant and cell stimulating activities of Annona muricata Linn.

    PubMed

    Nawwar, Mahmoud; Ayoub, Nahla; Hussein, Sahar; Hashim, Amani; El-Sharawy, Reham; Wende, Kristian; Harms, Manuela; Lindequist, Ulrike

    2012-05-01

    Chemical investigation on leaves of Annona muricata resulted in the isolation of the flavonol triglycoside, quercetin 3-O-α-rhamnosyl-(1″″ → 6″)-β-sophoroside, together with twelve known phenolics. The structures of these compounds were established by 1D- and 2D-nuclear magnetic resonance spectroscopic techniques and mass spectrometry data. The in vitro antioxidant studies of the investigated aqueous ethanol extract and its column fractions were accomplished using the oxygen radical absorbance capacity (ORAC) method. A stimulating effect on HaCaT human keratinocytes by the leaf extract was also assessed. Il-6 production after UV irradiation was not influenced by A. muricata leaf extract.

  20. Differential turnover of phospholipid acyl groups in mouse peritoneal macrophages

    SciTech Connect

    Kuwae, T.; Schmid, P.C.; Johnson, S.B.; Schmid, H.H. )

    1990-03-25

    Phospholipid acyl turnover was assessed in mouse peritoneal exudate cells which consisted primarily of macrophages. The cells were incubated for up to 5 h in media containing 40% H218O, and uptake of 18O into ester carbonyls of phospholipids was determined by gas chromatography-mass spectrometry of hydrogenated methyl esters. The uptake was highest in choline phospholipids and phosphatidylinositol, less in ethanolamine phospholipids, and much less in phosphatidylserine. Acyl groups at the sn-1 and sn-2 positions of diacyl glycerophospholipids, including arachidonic and other long-chain polyunsaturated fatty acids, acquired 18O at about the same rate. Acyl groups of alkylacyl glycerophosphocholine exhibited lower rates of 18O uptake, and acyl groups of ethanolamine plasmalogens (alkenylacyl glycerophosphoethanolamines) acquired only minimal amounts of 18O within 5 h, indicating a low average acyl turnover via free fatty acids. Pulse experiments with exogenous 3H-labeled arachidonic acid supported the concept that acylation of alkenyl glycerophosphoethanolamine occurs by acyl transfer from other phospholipids rather than via free fatty acids and acyl-CoA. The 18O content of intracellular free fatty acids increased gradually over a 5-h period, whereas in extracellular free fatty acids it reached maximal 18O levels within the first hour. Arachidonate and other long-chain polyunsaturated fatty acids were found to participate readily in deacylation-reacylation reactions but were present only in trace amounts in the free fatty acid pools inside and outside the cells. We conclude that acyl turnover of macrophage phospholipids through hydrolysis and reacylation is rapid but tightly controlled so that appreciable concentrations of free arachidonic acid do not occur.

  1. Competition between anthocyanin and flavonol biosynthesis produces spatial pattern variation of floral pigments between Mimulus species

    PubMed Central

    Yuan, Yao-Wu; Rebocho, Alexandra B.; Sagawa, Janelle M.; Stanley, Lauren E.; Bradshaw, Harvey D.

    2016-01-01

    Flower color patterns have long served as a model for developmental genetics because pigment phenotypes are visually striking, yet generally not required for plant viability, facilitating the genetic analysis of color and pattern mutants. The evolution of novel flower colors and patterns has played a key role in the adaptive radiation of flowering plants via their specialized interactions with different pollinator guilds (e.g., bees, butterflies, birds), motivating the search for allelic differences affecting flower color pattern in closely related plant species with different pollinators. We have identified LIGHT AREAS1 (LAR1), encoding an R2R3-MYB transcription factor, as the causal gene underlying the spatial pattern variation of floral anthocyanin pigmentation between two sister species of monkeyflower: the bumblebee-pollinated Mimulus lewisii and the hummingbird-pollinated Mimulus cardinalis. We demonstrated that LAR1 positively regulates FLAVONOL SYNTHASE (FLS), essentially eliminating anthocyanin biosynthesis in the white region (i.e., light areas) around the corolla throat of M. lewisii flowers by diverting dihydroflavonol into flavonol biosynthesis from the anthocyanin pigment pathway. FLS is preferentially expressed in the light areas of the M. lewisii flower, thus prepatterning the corolla. LAR1 expression in M. cardinalis flowers is much lower than in M. lewisii, explaining the unpatterned phenotype and recessive inheritance of the M. cardinalis allele. Furthermore, our gene-expression analysis and genetic mapping results suggest that cis-regulatory change at the LAR1 gene played a critical role in the evolution of different pigmentation patterns between the two species. PMID:26884205

  2. Advanced Knowledge of Three Important Classes of Grape Phenolics: Anthocyanins, Stilbenes and Flavonols

    PubMed Central

    Flamini, Riccardo; Mattivi, Fulvio; De Rosso, Mirko; Arapitsas, Panagiotis; Bavaresco, Luigi

    2013-01-01

    Grape is qualitatively and quantitatively very rich in polyphenols. In particular, anthocyanins, flavonols and stilbene derivatives play very important roles in plant metabolism, thanks to their peculiar characteristics. Anthocyanins are responsible for the color of red grapes and wines and confer organoleptic characteristics on the wine. They are used for chemotaxonomic studies and to evaluate the polyphenolic ripening stage of grape. They are natural colorants, have antioxidant, antimicrobial and anticarcinogenic activity, exert protective effects on the human cardiovascular system, and are used in the food and pharmaceutical industries. Stilbenes are vine phytoalexins present in grape berries and associated with the beneficial effects of drinking wine. The principal stilbene, resveratrol, is characterized by anticancer, antioxidant, anti-inflammatory and cardioprotective activity. Resveratrol dimers and oligomers also occur in grape, and are synthetized by the vine as active defenses against exogenous attack, or produced by extracellular enzymes released from pathogens in an attempt to eliminate undesirable toxic compounds. Flavonols are a ubiquitous class of flavonoids with photo-protection and copigmentation (together with anthocyanins) functions. The lack of expression of the enzyme flavonoid 3′,5′-hydroxylase in white grapes restricts the presence of these compounds to quercetin, kaempferol and isorhamnetin derivatives, whereas red grapes usually also contain myricetin, laricitrin and syringetin derivatives. In the last ten years, the technological development of analytical instrumentation, particularly mass spectrometry, has led to great improvements and further knowledge of the chemistry of these compounds. In this review, the biosynthesis and biological role of these grape polyphenols are briefly introduced, together with the latest knowledge of their chemistry. PMID:24084717

  3. Advanced knowledge of three important classes of grape phenolics: anthocyanins, stilbenes and flavonols.

    PubMed

    Flamini, Riccardo; Mattivi, Fulvio; De Rosso, Mirko; Arapitsas, Panagiotis; Bavaresco, Luigi

    2013-09-27

    Grape is qualitatively and quantitatively very rich in polyphenols. In particular, anthocyanins, flavonols and stilbene derivatives play very important roles in plant metabolism, thanks to their peculiar characteristics. Anthocyanins are responsible for the color of red grapes and wines and confer organoleptic characteristics on the wine. They are used for chemotaxonomic studies and to evaluate the polyphenolic ripening stage of grape. They are natural colorants, have antioxidant, antimicrobial and anticarcinogenic activity, exert protective effects on the human cardiovascular system, and are used in the food and pharmaceutical industries. Stilbenes are vine phytoalexins present in grape berries and associated with the beneficial effects of drinking wine. The principal stilbene, resveratrol, is characterized by anticancer, antioxidant, anti-inflammatory and cardioprotective activity. Resveratrol dimers and oligomers also occur in grape, and are synthetized by the vine as active defenses against exogenous attack, or produced by extracellular enzymes released from pathogens in an attempt to eliminate undesirable toxic compounds. Flavonols are a ubiquitous class of flavonoids with photo-protection and copigmentation (together with anthocyanins) functions. The lack of expression of the enzyme flavonoid 3',5'-hydroxylase in white grapes restricts the presence of these compounds to quercetin, kaempferol and isorhamnetin derivatives, whereas red grapes usually also contain myricetin, laricitrin and syringetin derivatives. In the last ten years, the technological development of analytical instrumentation, particularly mass spectrometry, has led to great improvements and further knowledge of the chemistry of these compounds. In this review, the biosynthesis and biological role of these grape polyphenols are briefly introduced, together with the latest knowledge of their chemistry.

  4. Differential effects of quercetin glycosides on GABAC receptor channel activity.

    PubMed

    Kim, Hyeon-Joong; Lee, Byung-Hwan; Choi, Sun-Hye; Jung, Seok-Won; Kim, Hyun-Sook; Lee, Joon-Hee; Hwang, Sung-Hee; Pyo, Mi-Kyung; Kim, Hyoung-Chun; Nah, Seung-Yeol

    2015-01-01

    Quercetin, a representative flavonoid, is a compound of low molecular weight found in various colored plants and vegetables. Quercetin shows a wide range of neuropharmacological activities. In fact, quercetin naturally exists as monomer-(quercetin-3-O-rhamnoside) (Rham1), dimer-(Rutin), or trimer-glycosides [quercetin-3-(2(G)-rhamnosylrutinoside)] (Rham2) at carbon-3 in fruits and vegetables. The carbohydrate components are removed after ingestion into gastrointestinal systems. The role of the glycosides attached to quercetin in the regulation of γ-aminobutyric acid class C (GABAC) receptor channel activity has not been determined. In the present study, we examined the effects of quercetin glycosides on GABAC receptor channel activity by expressing human GABAC alone in Xenopus oocytes using a two-electrode voltage clamp technique and also compared the effects of quercetin glycosides with quercetin. We found that GABA-induced inward current (I GABA ) was inhibited by quercetin or quercetin glycosides. The inhibitory effects of quercetin and its glycosides on I GABA were concentration-dependent and reversible in the order of Rutin ≈ quercetin ≈ Rham 1 > Rham 2. The inhibitory effects of quercetin and its glycosides on I GABA were noncompetitive and membrane voltage-insensitive. These results indicate that quercetin and its glycosides regulate GABAC receptor channel activity through interaction with a different site from that of GABA, and that the number of carbohydrate attached to quercetin might play an important role in the regulation of GABAC receptor channel activity.

  5. Three new sulphur glycosides from the seeds of Descurainia sophia.

    PubMed

    Feng, Wei-Sheng; Li, Chun-Ge; Zheng, Xiao-Ke; Li, Ling-Ling; Chen, Wen-Jing; Zhang, Yan-Li; Cao, Yan-Gang; Gong, Jian-Hong; Kuang, Hai-Xue

    2016-08-01

    Three new sulphur glycosides, raphanuside B-D (1-3), together with a known sulphur glycoside, raphanuside (4) were isolated from the decoction of the seeds of Descurainia sophia (L.) Webb ex Prantl, and the compound 4 was reported for the first time from this plant. Their structures were identified by means of UV, IR, 1D, 2D NMR (HSQC, HMBC and NOESY) and HR-ESI-MS spectroscopic data.

  6. Steroidal saponins and pregnane glycosides from Smilax microphylla.

    PubMed

    Lin, Tao; Huang, Hui-Lian; Liu, Rong-Hua; Shu, Ji-Cheng; Ren, Gang; Shao, Feng; Liu, Li-sha

    2012-12-01

    Six steroidal saponins and two pregnane glycosides were isolated from the BuOH subfraction of 70% EtOH extract of Smilax microphylla C.H.Wright, among them two were new compounds (1 and 7). Pregnane glycosides were firstly isolated from the genus Smilax (Smilacaceae). Structures of the new compounds were determined on the basis of HR-ESI-MS, 1D and 2D NMR spectroscopic analysis.

  7. Phenolic glycosides from sugar maple (Acer saccharum) bark.

    PubMed

    Yuan, Tao; Wan, Chunpeng; González-Sarrías, Antonio; Kandhi, Vamsikrishna; Cech, Nadja B; Seeram, Navindra P

    2011-11-28

    Four new phenolic glycosides, saccharumosides A-D (1-4), along with eight known phenolic glycosides, were isolated from the bark of sugar maple (Acer saccharum). The structures of 1-4 were elucidated on the basis of spectroscopic data analysis. All compounds isolated were evaluated for cytotoxicity effects against human colon tumorigenic (HCT-116 and Caco-2) and nontumorigenic (CCD-18Co) cell lines.

  8. Use of cardiac glycosides and risk of glioma.

    PubMed

    Seliger, Corinna; Meier, Christoph R; Jick, Susan S; Uhl, Martin; Bogdahn, Ulrich; Hau, Peter; Leitzmann, M F

    2016-04-01

    Cardiac glycosides induce apoptotic effects on glioma cells, but whether cardiac glycosides protect against risk for glioma is unknown. We therefore explored the relation between glycoside use and glioma risk using a large and validated database. We performed a case-control analysis using the Clinical Practice Research Datalink involving 2005 glioma cases diagnosed between 1995 and 2012 that were individually matched to 20,050 controls on age, gender, general practice, and number of years of active history in the database. Conditional logistic regression analysis was used to evaluate the association between cardiac glycosides and the risk of glioma adjusting for body mass index and smoking. We also examined use of common heart failure and arrhythmia medications to differentiate between a specific glycoside effect and a generic effect of treatment for congestive heart failure or arrhythmia. Cardiac glycoside use was inversely related to glioma incidence. After adjustment for congestive heart failure, arrhythmia, diabetes, and common medications used to treat those conditions, the OR of glioma was 0.47 (95% CI 0.27-0.81, Bonferroni-corrected p value = 0.024) for use versus non-use of cardiac glycosides, based on 17 exposed cases. In contrast, no associations were noted for other medications used to treat congestive heart failure or arrhythmias. The OR of glioma in people with congestive heart failure was 0.65 (95% CI 0.40-1.04), and for arrhythmia it was 1.01 (95% CI 0.78-1.31). These data indicate that cardiac glycoside use is independently associated with reduced glioma risk.

  9. Three New Steroidal Glycosides from the Roots of Cynanchum stauntonii

    PubMed Central

    Yu, Jin-Qian; Zhang, Zhi-Hui; Deng, An-Jun; Qin, Hai-Lin

    2013-01-01

    Three new steroidal glycosides, named as stauntosides L, M, and N (1–3), along with one known C21 steroidal glycoside, anhydrohirundigenin monothevetoside (4), were isolated from the 95% ethanol extract of the roots of Cynanchum stauntonii. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analyses, mainly 1D and 2D NMR, HRESI-MS, and chemical methods. PMID:23555098

  10. Role of acyl carrier protein isoforms in plant lipid metabolism

    SciTech Connect

    Not Available

    1990-01-01

    Although acyl carrier protein (ACP) is the best studied protein in plant fatty acid biosynthesis, the in vivo forms of ACPs and their steady state pools have not been examined previously in either seed or leaf. Information about the relative pool sizes of free ACP and its acyl-ACP intermediates is essential for understanding regulation of de novo fatty acid biosynthesis in plants. In this study we utilized antibodies directed against spinach ACP as a sensitive assay to analyze the acyl groups while they were still covalently attached to ACPs. 4 refs., 4 figs.

  11. Synthesis of coenzyme A thioesters using methyl acyl phosphates in an aqueous medium.

    PubMed

    Pal, Mohan; Bearne, Stephen L

    2014-12-28

    Regioselective S-acylation of coenzyme A (CoA) is achieved under aqueous conditions using various aliphatic and aromatic carboxylic acids activated as their methyl acyl phosphate monoesters. Unlike many hydrophobic activating groups, the anionic methyl acyl phosphate mixed anhydride is more compatible with aqueous solvents, making it useful for conducting acylation reactions in an aqueous medium.

  12. Stability of steviol glycosides in several food matrices.

    PubMed

    Jooken, Etienne; Amery, Ruis; Struyf, Tom; Duquenne, Barbara; Geuns, Jan; Meesschaert, Boudewijn

    2012-10-24

    As steviol glycosides are now allowed as a food additive in the European market, it is important to assess the stability of these steviol glycosides after they have been added to different food matrices. We analyzed and tested the stability of steviol glycosides in semiskimmed milk, soy drink, fermented milk drink, ice cream, full-fat and skimmed set yogurt, dry biscuits, and jam. The fat was removed by centrifugation from the dairy and soy drink samples. Proteins were precipitated by the addition of acetonitrile and also removed by centrifugation. Samples of jam were extracted with water. Dry biscuits were extracted with ethanol. The resulting samples were concentrated with solid-phase extraction and analyzed by high-performance liquid chromatography on a C18 stationary phase and a gradient of acetonitrile/aqueous 25 mM phosphoric acid. The accuracy was checked using a standard addition on some samples. For assessing the stability of the steviol glycosides, samples were stored in conditions relevant to each food matrix and analyzed periodically. The results indicate that steviol glycosides can be analyzed with good precision and accuracy in these food categories. The recovery was between 96 and 103%. The method was also validated by standard addition, which showed excellent agreement with the external calibration curve. No sign of decomposition of steviol glycosides was found in any of the samples.

  13. A R2R3-MYB Transcription Factor Regulates the Flavonol Biosynthetic Pathway in a Traditional Chinese Medicinal Plant, Epimedium sagittatum

    PubMed Central

    Huang, Wenjun; Khaldun, A. B. M.; Chen, Jianjun; Zhang, Chanjuan; Lv, Haiyan; Yuan, Ling; Wang, Ying

    2016-01-01

    Flavonols as plant secondary metabolites with vital roles in plant development and defense against UV light, have been demonstrated to be the main bioactive components (BCs) in the genus Epimedium plants, several species of which are used as materials for Herba Epimedii, an important traditional Chinese medicine. The flavonol biosynthetic pathway genes had been already isolated from Epimedium sagittatum, but a R2R3-MYB transcription factor regulating the flavonol synthesis has not been functionally characterized so far in Epimedium plants. In this study, we isolated and characterized the R2R3-MYB transcription factor EsMYBF1 involved in regulation of the flavonol biosynthetic pathway from E. sagittatum. Sequence analysis indicated that EsMYBF1 belongs to the subgroup 7 of R2R3-MYB family which contains the flavonol-specific MYB regulators identified to date. Transient reporter assay showed that EsMYBF1 strongly activated the promoters of EsF3H (flavanone 3-hydroxylase) and EsFLS (flavonol synthase), but not the promoters of EsDFRs (dihydroflavonol 4-reductase) and EsANS (anthocyanidin synthase) in transiently transformed Nicotiana benthamiana leaves. Both yeast two-hybrid assay and transient reporter assay validated EsMYBF1 to be independent of EsTT8, or AtTT8 bHLH regulators of the flavonoid pathway as cofactors. Ectopic expression of EsMYBF1 in transgenic tobacco resulted in the increased flavonol content and the decreased anthocyanin content in flowers. Correspondingly, the structural genes involved in flavonol synthesis were upregulated in the EsMYBF1 overexpression lines, including NtCHS (chalcone synthase), NtCHI (chalcone isomerase), NtF3H and NtFLS, whereas the late biosynthetic genes of the anthocyanin pathway (NtDFR and NtANS) were remarkably downregulated, compared to the controls. These results suggest that EsMYBF1 is a flavonol-specific R2R3-MYB regulator, and involved in regulation of the biosynthesis of the flavonol-derived BCs in E. sagittatum. Thus

  14. The activity of Rhizomuchor miehei lipase as a biocatalyst in enzymatic acylation of cyclic alcohol

    NASA Astrophysics Data System (ADS)

    Iftitah, Elvina Dhiaul; Srihardyastuti, Arie; Ariefin, Mokhamat

    2017-03-01

    We report the activity of Rhizomuchor miehei lipase (RML) as a biocatalyst, in particular the investigations concerning the effort of substrate-structure reactivity on the enzymatic acylation. The acylation was studied using acetic anhydride as an acyl donor and performed in n-hexane as a solvent. The selectivity of the enzymatic acylation was revealed by Gas Chromatography-Mass Spectra. We observed that, RML has shown different behavior when catalyzing the acylation of isopulegol and mixture of isopulegol and citronellal (ratio 1:1). The chemoselectivity for the O-acylation was improved when the acyl acceptor included mixture of isopulegol and citronellal

  15. Studies on the localization of the cardiac glycoside receptor

    PubMed Central

    Smith, Thomas W.; Wagner, Henry; Markis, John E.; Young, Michael

    1972-01-01

    The purpose of this study was to see whether the receptor for cardiac glycosides might be localized upon or within the plasma membrane of digitalis-sensitive cells. Ouabain and digoxin were joined covalently to several large protein molecules. These macromolecular conjugates are too large to enter intact cells; consequently, any pharmacologic or biochemical effects which they display should arise from interaction with a cell surface receptor. Conjugates were tested in several cardiac glycoside-sensitive systems: (a), contractility response of isolated cardiac muscle; (b), active 86Rb+ uptake by red cells; (c), enzymatic activity of isolated myocardial microsomal (Na+ + K+)-activated adenosine triphosphatase (ATPase); and (d), enzymatic activity of solubilized red cell (Na+ + K+)-activated ATPase. Results demonstrated that in all of these systems, the macromolecular-glycoside conjugates were 100- to 1000-fold less active than the free glycosides. Careful chromatographic examination of the various conjugates revealed that they contained a small but persistent free cardiac glycoside contaminant. The amount of this species ranged from 0.1 to 1.0% of the total macromolecule-bound glycoside, and its presence fully explains the levels of biologic activity observed with the conjugates. To try to minimize steric factors which could interfere with glycoside-receptor interaction, digoxin and ouabain were also coupled to macromolecule via long, flexible polyamide side-chains. These extended chain conjugates, in which the cardiac glycoside potentially lay some 30 A removed from the surface of the macromolecule, also exhibited negligible digitalis-like effects when tested upon isolated cardiac muscle, red cell 86Rb+ uptake, and enzymatic activity of cardiac microsomal (Na+ + K+)-ATPase. However, the extended chain conjugates were fully active when examined with the solubilized red cell (Na+ + K+)-ATPase system. To further ensure that the chemical reactions used to couple

  16. Acylated cyanidin 3-sambubioside-5-glucosides in Matthiola incana.

    PubMed

    Saito, N; Tatsuzawa, F; Nishiyama, A; Yokoi, M; Shigihara, A; Honda, T

    1995-03-01

    Four acylated cyanidin 3-sambubioside-5-glucosides were isolated from purple-violet flowers of Matthiola incana and their structures were determined by chemical and spectroscopic methods. Three acylated anthocyanins were cyanidin 3-O-(6-O-acyl-2-O-(2-O-sinapyl-beta-D-xylopyranosyl)-beta-D- glucopyranosides)-5-O-(6-O-malonyl-beta-D-glucopyranosides), in which the acyl group is p-coumaryl, caffeyl or ferulyl, respectively. The remaining pigment is free from malonic acid and was identified as cyanidin 3-O-(6-O-trans-ferulyl-2-O-(2- O-trans-sinapyl-beta-D-xylopyranosyl)-beta-D-glucopyranoside)-5-O- (beta-D-glucopyranoside). Analysis of the anthocyanin constituents in 16 purple-violet cultivars revealed that they contained the above triacylated anthocyanins in variable amounts as main pigments. An aromatic pair of pigments containing sinapic and ferulic acids are considered to produce an important intramolecular effect, making bluish colours in these flowers.

  17. Resin Glycosides from the Morning Glory Family

    NASA Astrophysics Data System (ADS)

    Pereda-Miranda, Rogelio; Rosas-Ramírez, Daniel; Castañeda-Gómez, Jhon

    Resin glycosides are part of a very extensive family of secondary metabolites known as glycolipids or lipo-oligosaccharides and are constituents of complex resins (glycoresins) (1) unique to the morning glory family, Convolvulaceae (2). These active principles are responsible for the drastic purgative action of all the important Convolvulaceous species used in traditional medicine throughout the world since ancient times. Several commercial purgative crude drugs can be prepared from the roots of different species of Mexican morning glories. Their incorporation as therapeutic agents in Europe is an outstanding example of the assimilation of botanical drugs from the Americas as substitutes for traditional Old World remedies (3). Even though phytochemical investigations on the constituents of these drugs were initiated during the second half of the nineteenth century, the structure of their active ingredients still remains poorly known for some examples of these purgative roots. During the last two decades, the higher resolution capabilities of modern analytical isolation techniques used in conjunction with powerful spectroscopic methods have facilitated the elucidation of the active principles of these relevant herbal products.

  18. A new lignan glycoside from Juniperus rigida.

    PubMed

    Woo, Kyeong Wan; Choi, Sang Un; Park, Jong Cheol; Lee, Kang Ro

    2011-12-01

    A new lignan glycoside, named juniperigiside (1) was isolated from the CHCl(3) soluble fraction of the MeOH extract of stems and leaves of Juniperus rigida S.et Z. Compound 1 was identified by 1D- and 2D-NMR spectroscopy as well as CD analysis as (2R,3S)-2,3-dihydro-7-methoxy-2-(4'-hydroxy-3'-methoxyphenyl)-3-hydroxymethyl-5-benzofuranpropanol 4'-O-(3-O-methyl)-α-L-rhamnopyranoside. Five known lignans, icariside E4 (2), desoxypodophyllotoxin (3), savinin (4), thujastandin (5), and (-)-nortrachelogenin (6) in addition to five known labdane diterpenes including trans-communic acid (7), 13-epi-torulosal (8), 13-epi-cupressic acid (9), imbricatoric acid (10), and isocupressic acid (11) were also isolated and their structures were characterized by comparing their spectroscopic data with those in the literature. All compounds were isolated for the first time from this plant, and 5 and 6 were first reported from the genus Juniperus. The isolated compounds were tested for cytotoxicity against four human tumor cell lines in vitro using a Sulforhodamin B bioassay. Compounds 3, 4, 7, and 8 showed considerable cytotoxicity against four human cancer cell lines in vitro.

  19. Acyl Meldrum's acid derivatives: application in organic synthesis

    NASA Astrophysics Data System (ADS)

    Janikowska, K.; Rachoń, J.; Makowiec, S.

    2014-07-01

    This review is focused on an important class of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleophiles. The possible mechanisms of these transformations are analyzed. The bibliography includes 134 references.

  20. Oxidative activation of dihydropyridine amides to reactive acyl donors.

    PubMed

    Funder, Erik Daa; Trads, Julie B; Gothelf, Kurt V

    2015-01-07

    Amides of 1,4-dihydropyridine (DHP) are activated by oxidation for acyl transfer to amines, alcohols and thiols. In the reduced form the DHP amide is stable towards reaction with amines at room temperature. However, upon oxidation with DDQ the acyl donor is activated via a proposed pyridinium intermediate. The activated intermediate reacts with various nucleophiles to give amides, esters, and thio-esters in moderate to high yields.

  1. Bio-inspired flavonol and quinolone dioxygenation by a non-heme iron catalyst modeling the action of flavonol and 3-hydroxy-4(1H)-quinolone 2,4-dioxygenases.

    PubMed

    Pap, József S; Matuz, Andrea; Baráth, Gábor; Kripli, Balázs; Giorgi, Michel; Speier, Gábor; Kaizer, József

    2012-03-01

    The mononuclear complex, Fe(III)(O-bs)(salen) (salenH(2)=1,6-bis(2-hydroxyphenyl)-2,5-diaza-hexa-1,5-diene; O-bsH=O-benzoylsalicylic acid) was synthesized as synthetic enzyme-depside complex, and characterized by spectroscopic methods and X-ray crystal analysis. The dioxygenation of flavonol (flaH) and 3-hydroxy-4-quinolone (quinH(2)) derivatives in the presence of catalytic amounts of Fe(III)(O-bs)(salen) results in the oxidative cleavage of the heterocyclic ring to give the corresponding O-benzoylsalicylic and anthranilic acid derivatives with concomitant release of carbon monoxide. These reactions can be regarded as biomimetic functional models with relevance to the iron-containing flavonol and the cofactor-independent 3-hydroxy-4(1H)-quinolone 2,4-dioxygenases.

  2. Glycosidic inhibitors of melanogenesis from leaves of Passiflora edulis.

    PubMed

    Zhang, Jie; Koike, Ryosuke; Yamamoto, Ayako; Ukiya, Motohiko; Fukatsu, Makoto; Banno, Norihiro; Miura, Motofumi; Motohashi, Shigeyasu; Tokuda, Harukuni; Akihisa, Toshihiro

    2013-10-01

    A new flavonoid glycoside, chrysin 6-C-β-rutinoside (chrysin α-L-rhamnopyranosyl-(1→6)-C-β-glucopyranoside; 2), and two new triterpene glycosides, (31R)-31-O-methylpassiflorine (7) and (31S)-31-O-methylpassiflorine (8), along with 14 known glycosides, including three flavonoid glycosides, 1, 3, and 4, six triterpene glycosides, 5, 6, and 9-12, three cyano glycosides, 13-15, and two other glycosides, 16 and 17, were isolated from a MeOH extract of the leaves of Passiflora edulis (passion flower; Passifloraceae). The structures of new compounds were elucidated on the basis of extensive spectroscopic analysis and comparison with literature data. Upon evaluation of compounds 1-17 against the melanogenesis in the B16 melanoma cells induced with α-melanocyte-stimulating hormone (α-MSH), three compounds, isoorientin (1), 2, and (6S,9R)-roseoside (17), exhibited inhibitory effects with 37.3-47.2% reduction of melanin content with no, or almost no, toxicity to the cells (90.8-100.2% cell viability) at 100 μM. Western blot analysis showed that compound 2 reduced the protein levels of MITF, TRP-1, and tyrosinase, in a concentration-dependent manner while exerted almost no influence on the level of TRP-2, suggesting that this compound inhibits melanogenesis on the α-MSH-stimulated B16 melanoma cells by, at least in part, inhibiting the expression of MITF, followed by decreasing the expression of TRP-1 and tyrosinase. In addition, compounds 1-17 were evaluated for their inhibitory effects against the EpsteinBarr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells.

  3. Structures of some novel α-glucosyl diterpene glycosides from the glycosylation of steviol glycosides.

    PubMed

    Prakash, Indra; Chaturvedula, Venkata Sai Prakash

    2014-12-04

    Four new minor diterpene glycosides with a rare α-glucosyl linkage were isolated from a cyclodextrin glycosyltransferase glucosylated stevia extract containing more than 98% steviol glycosides. The new compounds were identified as 13-[(2-O-β-D-glucopyranosyl-3-O-(4-O-α-D-glucopyranosyl)-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-α-D-glucopyranosyl-β-D-glucopyranosyl) ester] (1), 13-[(2-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-(4-O-(4-O-α-D-glucopyranosyl)-α-D-glucopyranosyl)-α-D-glucopyranosyl)-β-D-glucopyranosyl ester] (2), 13-[(2-O-β-D-glucopyranosyl-3-O-(4-O-(4-O-(4-O-α-D-glucopyranosyl)-α-D-glucopyranosyl)-α-D-glucopyranosyl)-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid β-D-glucopyranosyl ester (3), and 13-[(2-O-β-D-glucopyranosyl-3-O-(4-O-(4-O-(4-O-α-D-glucopyranosyl)-α-D-glucopyranosyl)-α-D-glucopyranosyl)-β-D-glucopyranosyl- β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-α-D-glucopyranosyl-β-D-glucopyranosyl) ester] (4) on the basis of extensive NMR and mass spectral (MS) data as well as hydrolysis studies.

  4. Synergistic effect of flavones and flavonols against herpes simplex virus type 1 in cell culture. Comparison with the antiviral activity of propolis.

    PubMed

    Amoros, M; Simões, C M; Girre, L; Sauvager, F; Cormier, M

    1992-12-01

    The in vitro activity against herpes simplex virus type 1 of the major flavonoids identified in propolis was investigated. Flavonols were found to be more active than flavones, the order of importance being galangin, kaempferol, and quercetin. The efficacy against HSV-1 of binary flavone-flavonol combinations has been also investigated. The synergy demonstrated by all combinations could explain why propolis is more active than its individual compounds.

  5. Characterization of a recently evolved flavonol-phenylacyltransferase gene provides signatures of natural light selection in Brassicaceae

    PubMed Central

    Tohge, Takayuki; Wendenburg, Regina; Ishihara, Hirofumi; Nakabayashi, Ryo; Watanabe, Mutsumi; Sulpice, Ronan; Hoefgen, Rainer; Takayama, Hiromitsu; Saito, Kazuki; Stitt, Mark; Fernie, Alisdair R.

    2016-01-01

    Incidence of natural light stress renders it important to enhance our understanding of the mechanisms by which plants protect themselves from harmful effects of UV-B irradiation, as this is critical for fitness of land plant species. Here we describe natural variation of a class of phenylacylated-flavonols (saiginols), which accumulate to high levels in floral tissues of Arabidopsis. They were identified in a subset of accessions, especially those deriving from latitudes between 16° and 43° North. Investigation of introgression line populations using metabolic and transcript profiling, combined with genomic sequence analysis, allowed the identification of flavonol-phenylacyltransferase 2 (FPT2) that is responsible for the production of saiginols and conferring greater UV light tolerance in planta. Furthermore, analysis of polymorphism within the FPT duplicated region provides an evolutionary framework of the natural history of this locus in the Brassicaceae. PMID:27545969

  6. Flavonol-induced changes in PIN2 polarity and auxin transport in the Arabidopsis thaliana rol1-2 mutant require phosphatase activity

    PubMed Central

    Kuhn, Benjamin M.; Nodzyński, Tomasz; Errafi, Sanae; Bucher, Rahel; Gupta, Shibu; Aryal, Bibek; Dobrev, Petre; Bigler, Laurent; Geisler, Markus; Zažímalová, Eva; Friml, Jiří; Ringli, Christoph

    2017-01-01

    The phytohormone auxin is a major determinant and regulatory component important for plant development. Auxin transport between cells is mediated by a complex system of transporters such as AUX1/LAX, PIN, and ABCB proteins, and their localization and activity is thought to be influenced by phosphatases and kinases. Flavonols have been shown to alter auxin transport activity and changes in flavonol accumulation in the Arabidopsis thaliana rol1-2 mutant cause defects in auxin transport and seedling development. A new mutation in ROOTS CURL IN NPA 1 (RCN1), encoding a regulatory subunit of the phosphatase PP2A, was found to suppress the growth defects of rol1-2 without changing the flavonol content. rol1-2 rcn1-3 double mutants show wild type-like auxin transport activity while levels of free auxin are not affected by rcn1-3. In the rol1-2 mutant, PIN2 shows a flavonol-induced basal-to-apical shift in polar localization which is reversed in the rol1-2 rcn1-3 to basal localization. In vivo analysis of PINOID action, a kinase known to influence PIN protein localization in a PP2A-antagonistic manner, revealed a negative impact of flavonols on PINOID activity. Together, these data suggest that flavonols affect auxin transport by modifying the antagonistic kinase/phosphatase equilibrium. PMID:28165500

  7. MK571 inhibits phase-2 conjugation of flavonols by Caco-2/TC7 cells, but does not specifically inhibit their apical efflux☆

    PubMed Central

    Barrington, Robert D.; Needs, Paul W.; Williamson, Gary; Kroon, Paul A.

    2015-01-01

    MK571 is a multidrug resistance protein-2 (ABCC2, Mrp2) inhibitor and has been widely used to demonstrate the role of Mrp2 in the cellular efflux of drugs, xenobiotics and their conjugates. Numerous reports have described modulation of Caco-2 cellular efflux and transport of flavonoids in the presence of MK571. Since flavonoids are efficiently conjugated by Caco-2/TC7 cells, we investigated the effects of MK571 on the efflux of flavonoid conjugates. The flavonol aglycones kaempferol, quercetin and galangin were efficiently taken up, conjugated and effluxed by Caco-2/TC7 cells. Apically-applied MK571 caused significant reductions in both the apical and basolateral efflux of flavonol conjugates from Caco-2/TC7 monolayers. MK571 did not significantly alter the apical:basolateral efflux ratio for flavonol conjugates, however, which is not consistent with MK571 specifically inhibiting only apical Mrp2. Since MK571 decreased the total amounts of conjugates formed, and increased cellular flavonol aglycone concentrations, we explored the possibility that MK571 also inhibits phase-2 conjugation of flavonols. MK571 dose-dependently inhibited the intracellular biosynthesis of all flavonol glucuronides and sulphates by Caco-2 cells. MK571 significantly inhibited phase-2 conjugation of kaempferol by cell-free extracts of Caco-2, and production of kaempferol-4′-O-glucuronide was competitively inhibited. These data show that MK571, in addition to inhibiting MRP2, is a potential inhibitor of enterocyte phase-2 conjugation. PMID:25801004

  8. Functional analyses of a flavonol synthase-like gene from Camellia nitidissima reveal its roles in flavonoid metabolism during floral pigmentation.

    PubMed

    Zhou, Xing-Wen; Fan, Zheng-Qi; Chen, Yue; Zhu, Yu-Lin; Li, Ji-Yuan; Yin, Heng-Fu

    2013-09-01

    The flavonoids metabolic pathway plays central roles in floral coloration, in which anthocyanins and flavonols are derived from common precursors, dihydroflavonols. Flavonol synthase (FLS) catalyses dihydroflavonols into flavonols, which presents a key branch of anthocyanins biosynthesis. The yellow flower of Camellia nitidissima Chi. is a unique feature within the genus Camellia, which makes it a precious resource for breeding yellow camellia varieties. In this work, we characterized the secondary metabolites of pigments during floral development of C. nitidissima and revealed that accumulation of flavonols correlates with floral coloration. We first isolated CnFLS1 and showed that it is a FLS of C. nitidissima by gene family analysis. Second, expression analysis during floral development and different floral organs indicated that the expression level of CnFLS1 was regulated by developmental cues, which was in agreement with the accumulating pattern of flavonols. Furthermore, over-expression of CnFLS1 in Nicotiana tabacum altered floral colour into white or light yellow, and metabolic analysis showed significant increasing of flavonols and reducing of anthocyanins in transgenic plants. Our work suggested CnFLS1 plays critical roles in yellow colour pigmentation and is potentially a key point of genetic engineering toward colour modification in Camellia.

  9. Steviol glycoside safety: is the genotoxicity database sufficient?

    PubMed

    Urban, J D; Carakostas, M C; Brusick, D J

    2013-01-01

    The safety of steviol glycoside sweeteners has been extensively reviewed in the literature. National and international food safety agencies and approximately 20 expert panels have concluded that steviol glycosides, including the widely used sweeteners stevioside and rebaudioside A, are not genotoxic. However, concern has been expressed in recent publications that steviol glycosides may be mutagenic based on select studies representing a small fraction of the overall database, and it has been suggested that further in vivo genotoxicity studies are required to complete their safety profiles. To address the utility of conducting additional in vivo genotoxicity studies, this review evaluates the specific genotoxicity studies that are the sources of concern, and evaluates the adequacy of the database including more recent genotoxicity data not mentioned in those publications. The current database of in vitro and in vivo studies for steviol glycosides is robust and does not indicate that either stevioside or rebaudioside A are genotoxic. This, combined with a lack of evidence for neoplasm development in rat bioassays, establish the safety of all steviol glycosides with respect to their genotoxic/carcinogenic potential.

  10. Human psychometric and taste receptor responses to steviol glycosides.

    PubMed

    Hellfritsch, Caroline; Brockhoff, Anne; Stähler, Frauke; Meyerhof, Wolfgang; Hofmann, Thomas

    2012-07-11

    Steviol glycosides, the sweet principle of Stevia Rebaudiana (Bertoni) Bertoni, have recently been approved as a food additive in the EU. The herbal non-nutritive high-potency sweeteners perfectly meet the rising consumer demand for natural food ingredients in Europe. We have characterized the organoleptic properties of the most common steviol glycosides by an experimental approach combining human sensory studies and cell-based functional taste receptor expression assays. On the basis of their potency to elicit sweet and bitter taste sensations, we identified glycone chain length, pyranose substitution, and the C16 double bond as the structural features giving distinction to the gustatory profile of steviol glycosides. A comprehensive screening of 25 human bitter taste receptors revealed that two receptors, hTAS2R4 and hTAS2R14, mediate the bitter off-taste of steviol glycosides. For some test substances, e.g., stevioside, we observed a decline in sweet intensity at supra-maximum concentrations. This effect did not arise from allosteric modulation of the hTAS1R2/R3 sweet taste receptor but might be explained by intramolecular cross-modal suppression between the sweet and bitter taste component of steviol glycosides. These results might contribute to the production of preferentially sweet and least bitter tasting Stevia extracts by an optimization of breeding and postharvest downstream processing.

  11. Analysis of anthocyanins and flavonols in petals of 10 Rhododendron species from the Sygera Mountains in Southeast Tibet.

    PubMed

    Liu, Lin; Zhang, Liang-Ying; Wang, Shu-Li; Niu, Xin-Yu

    2016-07-01

    Flower color is one of the major ornamental characteristics of the genus Rhododendron, but few studies on flower color in alpine Rhododendron have been reported. In our study, the flower colors and the pigment constituents of petals from 10 Rhododendron species sampled in the Sygera Mountains of Southeast Tibet were analyzed using high-performance liquid chromatography-diode array detection and mass spectrometry (HPLC-DAD-ESI-MS(2)). The color analysis showed that the 10 Rhododendron species could be divided into five color groupings: yellow, red, red-purple, purple-violet, and purple. A total of 5 anthocyanin compounds and 23 flavonol compounds were tentatively identified and quantified. There were obvious differences in the composition of anthocyanin and flavonol among the petals of the 10 Rhododendron species. The color parameter L* decreased as the TA (total anthocyanin) content increased in the red-purple group. However, there was no obvious correlation between the L* value and the TA content in the other sampled Rhododendron species. In this study, the TA values of most of the Rhododendron species were quite low, but the TF (total flavonol) content was high. These results indicate the existence of copigmentation effects in these 10 Rhododendron species.

  12. Nickel-catalyzed proton-deuterium exchange (HDX) procedures for glycosidic linkage analysis of complex carbohydrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The structural analysis of complex carbohydrates typically requires the assignment of three parameters: monosaccharide composition, the position of glycosidic linkages between monosaccharides, and the position and nature of non-carbohydrate substituents. The glycosidic linkage positions are often de...

  13. Cytotoxic Steroidal Glycosides from the Whole Plant of Calamus acanthophyllus.

    PubMed

    Prawat, Hunsa; Mahidol, Chulabhorn; Kaweetripob, Wirongrong; Intachote, Pakamas; Pisutjaroenpong, Somchai; Ruchirawat, Somsak

    2016-07-01

    A new steroidal glycoside, callaphylloside (1), together with seven known glycosides (2-8), was isolated from the whole plant of Calamus acanthophyllus. The structure of the new compound was elucidated by spectral data analyses and chemical transformations. Compounds 5 and 8 exhibited strong cytotoxic activity against four cancer cell lines (0.7 ≤ IC50 ≤ 3.4 µM). Evaluation of the structure-activity relationship among steroidal glycosides revealed that the structure of spirostanol with an α-L-rhamnopyranosyl linked to C-2 of the inner glucopyranosyl residue both play a critical role in the effects of these compounds on the cancer cell lines.

  14. 2-methyl-L-erythritol glycosides from Gardenia jasminoides.

    PubMed

    Yang, Liguo; Peng, Kaifeng; Zhao, Shizhe; Zhao, Feng; Chen, Lixia; Qiu, Feng

    2013-09-01

    Two new glycosides, 2-methyl-L-erythritol-4-O-(6-O-trans-sinapoyl)-β-D-glucopyranoside (1) and 2-methyl-L-erythritol-1-O-(6-O-trans-sinapoyl)-β-D-glucopyranoside (2), along with two known triterpenoids (3-4), four quinic acid derivatives (5-8) and one flavonoid (9) were isolated from the fruit of Gardenia jasminoides. Their structures were elucidated through MS and 2D NMR experiments (HMQC and HMBC). Inhibitory effects of the isolated compounds on nitric oxide production in lipopolysaccharide-activated macrophages were evaluated. Though 2-methyl-D-erythritol and its glycosides have been reported in a few references, this is the first report about 2-methyl-L-erythritol glycosides. Based on this finding, we propose that 2-methyl-L-erythritol might be a new intermediate in the non-mevalonate biosynthesis of terpenoids.

  15. Sesquiterpene glycosides from the roots of Codonopsis pilosula

    PubMed Central

    Jiang, Yueping; Liu, Yufeng; Guo, Qinglan; Xu, Chengbo; Zhu, Chenggen; Shi, Jiangong

    2015-01-01

    Three new sesquiterpene glycosides, named codonopsesquilosides A−C (1−3), were isolated from an aqueous extract of the dried roots of Codonopsis pilosula. Their structures including absolute configurations were determined by spectroscopic and chemical methods. These glycosides are categorized as C15 carotenoid (1), gymnomitrane (2), and eudesmane (3) types of sesquiterpenoids, respectively. Compound 1 is the first diglycoside of C15 carotenoids to be reported. Compound 2 represents the second reported example of gymnomitrane-type sesquiterpenoids from higher plants. The absolute configurations were supported by comparison of the experimental circular dichroism (CD) spectra with the calculated electronic CD (ECD) spectra of 1−3, their aglycones, and model compounds based on quantum-mechanical time-dependent density functional theory. The influences of the glycosyls on the calculated ECD spectra of the glycosidic sesquiterpenoids, as well as some nomenclature and descriptive problems with gymnomitrane-type sesquiterpenoids are discussed. PMID:26904398

  16. Detoxification of polycyclic aromatic hydrocarbons (PAHs) in Arabidopsis thaliana involves a putative flavonol synthase

    PubMed Central

    Hernández-Vega, Juan C.; Cady, Brian; Kayanja, Gilbert; Mauriello, Anthony; Cervantes, Natalie; Gillespie, Andrea; Lavia, Lisa; Trujillo, Joshua; Alkio, Merianne; Colón-Carmona, Adán

    2017-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants with cytotoxic, teratogenic and carcinogenic properties. Bioremediation studies with bacteria have led to the identification of dioxygenases (DOXs) in the first step to degrade these recalcitrant compounds. In this study, we characterized the role of the Arabidopsis thaliana AT5G05600, a putative DOX of the flavonol synthase family, in the transformation of PAHs. Phenotypic analysis of loss-of-function mutant lines showed that these plant lines were less sensitive to the toxic effects of phenanthrene, suggesting possible roles of this gene in PAH degradation in vivo. Interestingly, these mutant lines showed less accumulation of H2O2 after PAH exposure. Transgenic lines over-expressing At5g05600 showed a hypersensitive response and more oxidative stress after phenanthrene treatments. Moreover, fluorescence spectra results of biochemical assays with the recombinant His-tagged protein AT5G05600 detected chemical modifications of phenanthrene. Taken together, these results support the hypothesis that AT5G05600 is involved in the catabolism of PAHs and the accumulation of toxic intermediates during PAH biotransformation in plants. This research represents the first step in the design of transgenic plants with the potential to degrade PAHs, leading to the development of vigorous plant varieties that can reduce the levels of these pollutants in the environment. PMID:27637093

  17. Genetically engineered flavonol enriched tomato fruit modulates chondrogenesis to increase bone length in growing animals.

    PubMed

    Choudhary, Dharmendra; Pandey, Ashutosh; Adhikary, Sulekha; Ahmad, Naseer; Bhatia, Chitra; Bhambhani, Sweta; Trivedi, Prabodh Kumar; Trivedi, Ritu

    2016-02-26

    Externally visible body and longitudinal bone growth is a result of proliferation of chondrocytes. In growth disorder, there is delay in the age associated increase in height. The present study evaluates the effect of extract from transgenic tomato fruit expressing AtMYB12 transcription factor on bone health including longitudinal growth. Constitutive expression of AtMYB12 in tomato led to a significantly enhanced biosynthesis of flavonoids in general and the flavonol biosynthesis in particular. Pre-pubertal ovary intact BALB/c mice received daily oral administration of vehicle and ethanolic extract of wild type (WT-TOM) and transgenic AtMYB12-tomato (MYB12-TOM) fruits for six weeks. Animal fed with MYB12-TOM showed no inflammation in hepatic tissues and normal sinusoidal Kupffer cell morphology. MYB12-TOM extract significantly increased tibial and femoral growth and subsequently improved the bone length as compared to vehicle and WT-TOM. Histomorphometry exhibited significantly wider distal femoral and proximal tibial growth plate, increased number and size of hypertrophic chondrocytes in MYB12-TOM which corroborated with micro-CT and expression of BMP-2 and COL-10, marker genes for hypertrophic cells. We conclude that metabolic reprogramming of tomato by AtMYB12 has the potential to improve longitudinal bone growth thus helping in achievement of greater peak bone mass during adolescence.

  18. Genetically engineered flavonol enriched tomato fruit modulates chondrogenesis to increase bone length in growing animals

    PubMed Central

    Choudhary, Dharmendra; Pandey, Ashutosh; Adhikary, Sulekha; Ahmad, Naseer; Bhatia, Chitra; Bhambhani, Sweta; Trivedi, Prabodh Kumar; Trivedi, Ritu

    2016-01-01

    Externally visible body and longitudinal bone growth is a result of proliferation of chondrocytes. In growth disorder, there is delay in the age associated increase in height. The present study evaluates the effect of extract from transgenic tomato fruit expressing AtMYB12 transcription factor on bone health including longitudinal growth. Constitutive expression of AtMYB12 in tomato led to a significantly enhanced biosynthesis of flavonoids in general and the flavonol biosynthesis in particular. Pre-pubertal ovary intact BALB/c mice received daily oral administration of vehicle and ethanolic extract of wild type (WT-TOM) and transgenic AtMYB12-tomato (MYB12-TOM) fruits for six weeks. Animal fed with MYB12-TOM showed no inflammation in hepatic tissues and normal sinusoidal Kupffer cell morphology. MYB12-TOM extract significantly increased tibial and femoral growth and subsequently improved the bone length as compared to vehicle and WT-TOM. Histomorphometry exhibited significantly wider distal femoral and proximal tibial growth plate, increased number and size of hypertrophic chondrocytes in MYB12-TOM which corroborated with micro-CT and expression of BMP-2 and COL-10, marker genes for hypertrophic cells. We conclude that metabolic reprogramming of tomato by AtMYB12 has the potential to improve longitudinal bone growth thus helping in achievement of greater peak bone mass during adolescence. PMID:26917158

  19. Crystal structure of a human cyclin-dependent kinase 6 complexwith a flavonol inhibitor, Fisetin

    SciTech Connect

    Lu, Heshu; Chang, Debbie J.; Baratte, Blandine; Meijer, Laurent; Schulze-Gahmen, Ursula

    2005-01-10

    Cyclin-dependent kinases (CDKs) play a central role in cell cycle control, apoptosis, transcription and neuronal functions. They are important targets for the design of drugs with anti-mitotic and/or anti-neurodegenerative effects. CDK4 and CDK6 form a subfamily among the CDKs in mammalian cells, as defined by sequence similarities. Compared to CDK2 and CDK5, structural information on CDK4 and CDK6 is sparse. We describe here the crystal structure of human CDK6 in complex with a viral cyclin and a flavonol inhibitor, fisetin. Fisetin binds to the active form of CDK6, forming hydrogen bonds with the side chains of residues in the binding pocket that undergo large conformational changes during CDK activation by cyclin binding. The 4-keto group and the 3-hydroxyl group of fisetin are hydrogen bonded with the backbone in the hinge region between the N-terminal and C-terminal kinase domain, as has been observed for many CDK inhibitors. However, CDK2 and HCK kinase in complex with other flavone inhibitors such as quercetin and flavopiridol showed a different binding mode with the inhibitor rotated by about 180. The structural information of the CDK6-fisetin complex is correlated with the binding affinities of different flavone inhibitors for CDK6. This complex structure is the first description of an inhibitor complex with a kinase from the CDK4/6 subfamily and can provide a basis for selecting and designing inhibitor compounds with higher affinity and specificity.

  20. Application of Differential Colorimetry To Evaluate Anthocyanin-Flavonol-Flavanol Ternary Copigmentation Interactions in Model Solutions.

    PubMed

    Gordillo, Belén; Rodríguez-Pulido, Francisco J; González-Miret, M Lourdes; Quijada-Morín, Natalia; Rivas-Gonzalo, Julián C; García-Estévez, Ignacio; Heredia, Francisco J; Escribano-Bailón, M Teresa

    2015-09-09

    The combined effect of anthocyanin-flavanol-flavonol ternary interactions on the colorimetric and chemical stability of malvidin-3-glucoside has been studied. Model solutions with fixed malvidin-3-glucoside/(+)-catechin ratio (MC) and variable quercetin-3-β-d-glucoside concentration (MC+Q) and solutions with fixed malvidin-3-glucoside/quercetin-3-β-d-glucoside ratio (MQ) and variable (+)-catechin concentration (MQ+C) were tested at levels closer to those existing in wines. Color variations during storage were evaluated by differential colorimetry. Changes in the anthocyanin concentration were monitored by HPLC-DAD. CIELAB color-difference formulas were demonstrated to be of practical interest to assess the stronger and more stable interaction of quercetin-3-β-d-glucoside with MC binary mixture than (+)-catechin with MQ mixture. The results imply that MC+Q ternary solutions kept their intensity and bluish tonalities for a longer time in comparison to MQ+C solutions. The stability of malvidin-3-glucoside improves when the concentration of quercetin-3-β-d-glucoside increases in MC+Q mixtures, whereas the addition of (+)-catechin in MQ+C mixtures resulted in an opposite effect.

  1. Galangin, a flavonol derived from Rhizoma Alpiniae Officinarum, inhibits acetylcholinesterase activity in vitro.

    PubMed

    Guo, Ava J Y; Xie, Heidi Q; Choi, Roy C Y; Zheng, Ken Y Z; Bi, Cathy W C; Xu, Sherry L; Dong, Tina T X; Tsim, Karl W K

    2010-09-06

    Acetylcholinesterase (AChE) inhibitors are widely used for the treatment of Alzheimer's disease (AD). Several AChE inhibitors, e.g. rivastigmine, galantamine and huperzine are originating from plants, suggesting that herbs could potentially serve as sources for novel AChE inhibitors. Here, we searched potential AChE inhibitors from flavonoids, a group of naturally occurring compounds in plants or traditional Chinese medicines (TCM). Twenty-one flavonoids, covered different subclasses, were tested for their potential function in inhibiting AChE activity from the brain in vitro. Among all the tested flavonoids, galangin, a flavonol isolated from Rhizoma Alpiniae Officinarum, the rhizomes of Alpiniae officinarum (Hance.) showed an inhibitory effect on AChE activity with the highest inhibition by over 55% and an IC(50) of 120 microM and an enzyme-flavonoid inhibition constant (K(i)) of 74 microM. The results suggest that flavonoids could be potential candidates for further development of new drugs against AD.

  2. New Flavonol Glucuronides from the Flower Buds of Syzygium aromaticum (Clove).

    PubMed

    Ryu, Byeol; Kim, Hye Mi; Lee, Jin Su; Lee, Chan Kyu; Sezirahiga, Jurdas; Woo, Jeong-Hwa; Choi, Jung-Hye; Jang, Dae Sik

    2016-04-20

    Repeated chromatography of the EtOAc-soluble fraction from the 70% EtOH extract of the flower buds of Syzygium aromaticum (clove) led to the isolation and characterization of four new flavonol glucuronides, rhamnetin-3-O-β-d-glucuronide (1), rhamnazin-3-O-β-d-glucuronide (2), rhamnazin-3-O-β-d-glucuronide-6″-methyl ester (3), and rhamnocitrin-3-O-β-d-glucuronide-6″-methyl ester (4), together with 15 flavonoids (5-19) having previously known chemical structures. The structures of the new compounds 1-4 were determined by interpretation of spectroscopic data, particularly by 1D- and 2D-NMR studies. Six flavonoids (6, 7, 9, 14, 18, and 19) were isolated from the flower buds of S. aromaticum for the first time in this study. The flavonoids were examined for their cytotoxicity against human ovarian cancer cells (A2780) using MTT assays. Among the isolates, pachypodol (19) showed the most potent cytotoxicity on A2780 cells with an IC50 value of 8.02 μM.

  3. Head-group acylation of monogalactosyldiacylglycerol is a common stress response, but the acyl-galactose acyl composition varies with the plant species and applied stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Head group acylation of monogalactosyldiacylglycerol is a plant lipid modification occurring during bacterial infection. Little is known about the range of stresses that induce this lipid modification, the molecular species induced, and the function of the modification. Lipidomic analysis using trip...

  4. Chemical and biological properties of quinochalcone C-glycosides from the florets of Carthamus tinctorius.

    PubMed

    Yue, Shijun; Tang, Yuping; Li, Shujiao; Duan, Jin-Ao

    2013-12-10

    Quinochalcone C-glycosides are regarded as characteristic components that have only been isolated from the florets of Carthamus tinctorius. Recently, quinochalcone C-glycosides were found to have multiple pharmacological activities, which has attracted the attention of many researchers to explore these compounds. This review aims to summarize quinochalcone C-glycosides' physicochemical properties, chromatographic behavior, spectroscopic characteristics, as well as their biological activities, which will be helpful for further study and development of quinochalcone C-glycosides.

  5. Cytotoxic cardiac glycosides and other compounds from Asclepias syriaca.

    PubMed

    Araya, Juan J; Kindscher, Kelly; Timmermann, Barbara N

    2012-03-23

    Phytochemical investigation of the dried biomass of Asclepias syriaca afforded five new compounds (1-5), along with 19 known structures. Overall, the secondary metabolites isolated and identified from this plant showed a wide structural diversity including pentacyclic triterpenes, cardiac glycosides, flavonoid glycosides, lignans, a phenylethanoid, and a glycosylated megastigmane. In addition, the isolates were tested against the cancer breast cell line Hs578T, and those showing IC(50) values lower than 50 μM (1 and 6-9) were further investigated in three additional breast cancer cell lines (MCF-7, T47D, and Sk-Br-3) and the normal breast cell line Hs578Bst.

  6. A glycoside of Nicotina tabacum affects mouse dopaminergic behavior.

    PubMed

    Masuda, Y; Ohnuma, S; Kawagoe, M; Sugiyama, T

    2003-01-01

    Climbing in the forced swimming test is considered a dopaminergic-specific behavior. A substance of Nicotina tabacum affecting dopamine neuronal activity was investigated using the mouse behavioral system. The substance was found to be a glycoside with the peripheral sugar chain structures Fuc alpha 1-2Gal, Gal beta 1-4GlcNAc and GalNAc alpha 1-3GalNAc and with basic polymannoses. The glycoside dose-dependently increased behavior via D2 neuronal activity, but not D1 activity. This suggests that smoking can affect human brain function not only via the nicotinic cholinergic neuron, but also via the D2 neuron.

  7. Bioactive glycosides from the African medicinal plant Boerhavia erecta L.

    PubMed

    Nugraha, Ari S; Hilou, Adama; Vandegraaff, Nicholas; Rhodes, David I; Haritakun, Rachada; Keller, Paul A

    2015-01-01

    Phytochemical studies of the previously unexplored stem of Boerhavia erecta from Burkina Faso, resulted in the isolation of an unreported glycoside 4, 2,3-dihydroxypropylbenzoate-3-O-β-[4″-methoxy] glucuronide as well as seven known glycosides (1-3, 5-8). The major isolate 5 and 8 indicated a significant inhibition against HIV integrase (IC50 10 and 22 μg/mL, respectively). The extracts and isolates were also tested for anti-malarial activity, but insignificant activity was observed.

  8. Two fatty acyl reductases involved in moth pheromone biosynthesis

    PubMed Central

    Antony, Binu; Ding, Bao-Jian; Moto, Ken’Ichi; Aldosari, Saleh A.; Aldawood, Abdulrahman S.

    2016-01-01

    Fatty acyl reductases (FARs) constitute an evolutionarily conserved gene family found in all kingdoms of life. Members of the FAR gene family play diverse roles, including seed oil synthesis, insect pheromone biosynthesis, and mammalian wax biosynthesis. In insects, FAR genes dedicated to sex pheromone biosynthesis (pheromone-gland-specific fatty acyl reductase, pgFAR) form a unique clade that exhibits substantial modifications in gene structure and possesses unique specificity and selectivity for fatty acyl substrates. Highly selective and semi-selective ‘single pgFARs’ produce single and multicomponent pheromone signals in bombycid, pyralid, yponomeutid and noctuid moths. An intriguing question is how a ‘single reductase’ can direct the synthesis of several fatty alcohols of various chain lengths and isomeric forms. Here, we report two active pgFARs in the pheromone gland of Spodoptera, namely a semi-selective, C14:acyl-specific pgFAR and a highly selective, C16:acyl-specific pgFAR, and demonstrate that these pgFARs play a pivotal role in the formation of species-specific signals, a finding that is strongly supported by functional gene expression data. The study envisages a new area of research for disclosing evolutionary changes associated with C14- and C16-specific FARs in moth pheromone biosynthesis. PMID:27427355

  9. Regioselective self-acylating cyclodextrins in organic solvent

    PubMed Central

    Cho, Eunae; Yun, Deokgyu; Jeong, Daham; Im, Jieun; Kim, Hyunki; Dindulkar, Someshwar D.; Choi, Youngjin; Jung, Seunho

    2016-01-01

    Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrate in organic solvent. In the self-acylation, the most acidic OH group at the 2-position and the inclusion complexing ability of cyclodextrin were considered to be significant. The substrate preference was also observed in favor of the long-chain acyl group, which could be attributed to the inclusion ability of cyclodextrin cavity. Furthermore, using the model amphiphilic building block, 2-O-mono-lauryl β-cyclodextrin, the self-organized supramolecular architecture with nano-vesicular morphology in water was investigated by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. The cavity-type nano-assembled vesicle and the novel synthetic methods for the preparation of mono-acylated cyclodextrin should be of great interest with regard to drug/gene delivery systems, functional surfactants, and carbohydrate derivatization methods. PMID:27020946

  10. An annotated database of Arabidopsis mutants of acyl lipid metabolism

    SciTech Connect

    McGlew, Kathleen; Shaw, Vincent; Zhang, Meng; Kim, Ryeo Jin; Yang, Weili; Shorrosh, Basil; Suh, Mi Chung; Ohlrogge, John

    2014-12-10

    Mutants have played a fundamental role in gene discovery and in understanding the function of genes involved in plant acyl lipid metabolism. The first mutant in Arabidopsis lipid metabolism (fad4) was described in 1985. Since that time, characterization of mutants in more than 280 genes associated with acyl lipid metabolism has been reported. This review provides a brief background and history on identification of mutants in acyl lipid metabolism, an analysis of the distribution of mutants in different areas of acyl lipid metabolism and presents an annotated database (ARALIPmutantDB) of these mutants. The database provides information on the phenotypes of mutants, pathways and enzymes/proteins associated with the mutants, and allows rapid access via hyperlinks to summaries of information about each mutant and to literature that provides information on the lipid composition of the mutants. Mutants for at least 30 % of the genes in the database have multiple names, which have been compiled here to reduce ambiguities in searches for information. Furthermore, the database should also provide a tool for exploring the relationships between mutants in acyl lipid-related genes and their lipid phenotypes and point to opportunities for further research.

  11. An annotated database of Arabidopsis mutants of acyl lipid metabolism

    DOE PAGES

    McGlew, Kathleen; Shaw, Vincent; Zhang, Meng; ...

    2014-12-10

    Mutants have played a fundamental role in gene discovery and in understanding the function of genes involved in plant acyl lipid metabolism. The first mutant in Arabidopsis lipid metabolism (fad4) was described in 1985. Since that time, characterization of mutants in more than 280 genes associated with acyl lipid metabolism has been reported. This review provides a brief background and history on identification of mutants in acyl lipid metabolism, an analysis of the distribution of mutants in different areas of acyl lipid metabolism and presents an annotated database (ARALIPmutantDB) of these mutants. The database provides information on the phenotypes ofmore » mutants, pathways and enzymes/proteins associated with the mutants, and allows rapid access via hyperlinks to summaries of information about each mutant and to literature that provides information on the lipid composition of the mutants. Mutants for at least 30 % of the genes in the database have multiple names, which have been compiled here to reduce ambiguities in searches for information. Furthermore, the database should also provide a tool for exploring the relationships between mutants in acyl lipid-related genes and their lipid phenotypes and point to opportunities for further research.« less

  12. Regioselective self-acylating cyclodextrins in organic solvent

    NASA Astrophysics Data System (ADS)

    Cho, Eunae; Yun, Deokgyu; Jeong, Daham; Im, Jieun; Kim, Hyunki; Dindulkar, Someshwar D.; Choi, Youngjin; Jung, Seunho

    2016-03-01

    Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrate in organic solvent. In the self-acylation, the most acidic OH group at the 2-position and the inclusion complexing ability of cyclodextrin were considered to be significant. The substrate preference was also observed in favor of the long-chain acyl group, which could be attributed to the inclusion ability of cyclodextrin cavity. Furthermore, using the model amphiphilic building block, 2-O-mono-lauryl β-cyclodextrin, the self-organized supramolecular architecture with nano-vesicular morphology in water was investigated by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. The cavity-type nano-assembled vesicle and the novel synthetic methods for the preparation of mono-acylated cyclodextrin should be of great interest with regard to drug/gene delivery systems, functional surfactants, and carbohydrate derivatization methods.

  13. Steviol glycosides in purified stevia leaf extract sharing the same metabolic fate.

    PubMed

    Purkayastha, Sidd; Markosyan, Avetik; Prakash, Indra; Bhusari, Sachin; Pugh, George; Lynch, Barry; Roberts, Ashley

    2016-06-01

    The safety of steviol glycosides is based on data available on several individual steviol glycosides and on the terminal absorbed metabolite, steviol. Many more steviol glycosides have been identified, but are not yet included in regulatory assessments. Demonstration that these glycosides share the same metabolic fate would indicate applicability of the same regulatory paradigm. In vitro incubation assays with pooled human fecal homogenates, using rebaudiosides A, B, C, D, E, F and M, as well as steviolbioside and dulcoside A, at two concentrations over 24-48 h, were conducted to assess the metabolic fate of various steviol glycoside classes and to demonstrate that likely all steviol glycosides are metabolized to steviol. The data show that glycosidic side chains containing glucose, rhamnose, xylose, fructose and deoxy-glucose, including combinations of α(1-2), β-1, β(1-2), β(1-3), and β(1-6) linkages, were degraded to steviol mostly within 24 h. Given a common metabolite structure and a shared metabolic fate, safety data available for individual steviol glycosides can be used to support safety of purified steviol glycosides in general. Therefore, steviol glycosides specifications adopted by the regulatory authorities should include all steviol glycosides belonging to the five groups of steviol glycosides and a group acceptable daily intake established.

  14. Interleukin-6 as a Potential Indicator for Prevention of High Risk Adenoma Recurrence by Dietary Flavonols in the Polyp Prevention Trial

    PubMed Central

    Bobe, Gerd; Albert, Paul S.; Sansbury, Leah B.; Lanza, Elaine; Schatzkin, Arthur; Colburn, Nancy H.; Cross, Amanda J.

    2010-01-01

    Serum interleukin (IL)-6, a pro-inflammatory cytokine, is considered an indicator of inflammation and may be an indicator of colorectal carcinogenesis given that inflammation can promote carcinogenesis. Flavonols, which can be found in fruits and vegetables, may inhibit colorectal carcinogenesis partly by inhibiting inflammation. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) to determine whether serum IL-6 was associated with colorectal adenoma recurrence and flavonol intake and, thus may serve as a risk indicator and as a response indicator to dietary flavonols. Serum IL-6 concentrations at baseline, year 1 and 3 were measured in 872 participants from the intervention arm of the Polyp Prevention Trial, a 4-year trial that examined the effectiveness of a low-fat, high-fiber, high-fruit and vegetable diet on adenoma recurrence. Intake of flavonols, especially of isorhamnetin, kaempferol, and quercetin, was inversely associated with serum IL-6 concentrations (highest vs. lowest flavonol intake quartile, 1.80 vs. 2.20 pg/mL) and high risk (OR = 0.51, 95% CI: 0.26–0.98) and advanced adenoma recurrence (OR = 0.17, 95% CI: 0.06–0.50). A decrease in IL-6 concentration during the trial was inversely associated with high risk (OR = 0.44, 95% CI: 0.23–0.84) and advanced adenoma recurrence (OR = 0.47, 95% CI: 0.19–1.18). Individuals with above median flavonol intake and equal or below median IL-6 change after baseline had the lowest risk of recurrence of high risk and advanced adenoma. Our results suggest that serum IL-6 may serve as a risk indicator and as a response indicator to dietary flavonols for colorectal cancer prevention. PMID:20484173

  15. Trapping of the Enoyl-Acyl Carrier Protein Reductase–Acyl Carrier Protein Interaction

    PubMed Central

    Tallorin, Lorillee; Finzel, Kara; Nguyen, Quynh G.; Beld, Joris; La Clair, James J.; Burkart, Michael D.

    2016-01-01

    An ideal target for metabolic engineering, fatty acid biosynthesis remains poorly understood on a molecular level. These carrier protein-dependent pathways require fundamental protein–protein interactions to guide reactivity and processivity, and their control has become one of the major hurdles in successfully adapting these biological machines. Our laboratory has developed methods to prepare acyl carrier proteins (ACPs) loaded with substrate mimetics and cross-linkers to visualize and trap interactions with partner enzymes, and we continue to expand the tools for studying these pathways. We now describe application of the slow-onset, tight-binding inhibitor triclosan to explore the interactions between the type II fatty acid ACP from Escherichia coli, AcpP, and its corresponding enoyl-ACP reductase, FabI. We show that the AcpP–triclosan complex demonstrates nM binding, inhibits in vitro activity, and can be used to isolate FabI in complex proteomes. PMID:26938266

  16. A Comparative Analysis of Acyl-Homoserine Lactone Synthase Assays.

    PubMed

    Shin, Daniel; Frane, Nicole D; Brecht, Ryan M; Keeler, Jesse; Nagarajan, Rajesh

    2015-12-01

    Quorum sensing is cell-to-cell communication that allows bacteria to coordinate attacks on their hosts by inducing virulent gene expression, biofilm production, and other cellular functions, including antibiotic resistance. AHL synthase enzymes synthesize N-acyl-l-homoserine lactones, commonly referred to as autoinducers, to facilitate quorum sensing in Gram-negative bacteria. Studying the synthases, however, has proven to be a difficult road. Two assays, including a radiolabeled assay and a colorimetric (DCPIP) assay are well-documented in literature to study AHL synthases. In this paper, we describe additional methods that include an HPLC-based, C-S bond cleavage and coupled assays to investigate this class of enzymes. In addition, we compare and contrast each assay for both acyl-CoA- and acyl-ACP-utilizing synthases. The expanded toolkit described in this study should facilitate mechanistic studies on quorum sensing signal synthases and expedite discovery of antivirulent compounds.

  17. Asymmetric Allylboration of Acyl Imines Catalyzed by Chiral Diols

    PubMed Central

    Lou, Sha; Moquist, Philip N.; Schaus, Scott E.

    2008-01-01

    Chiral BINOL-derived diols catalyze the enantioselective asymmetric allylboration of acyl imines. The reaction requires 15 mol% of (S)-3,3′-Ph2-BINOL as the catalyst and allyldiisopropoxyborane as the nucleophile. The reaction products are obtained in good yields (75 – 94%) and high enantiomeric ratios (95:5 – 99.5:0.5) for aromatic and aliphatic imines. High diastereoselectivities (dr > 98:2) and enantioselectivities (er > 98:2) are obtained in the reactions of acyl imines with crotyldiisopropoxyboranes. This asymmetric transformation is directly applied to the synthesis of maraviroc, the selective CCR5 antagonist with potent activity against HIV-1 infection. Mechanistic investigations of the allylboration reaction including IR, NMR, and mass spectrometry study indicate that acyclic boronates are activated by chiral diols via exchange of one of the boronate alkoxy groups with activation of the acyl imine via hydrogen bonding. PMID:18020334

  18. Synthesis of sugars embodying conjugated carbonyl systems and related triazole derivatives from carboxymethyl glycoside lactones. Evaluation of their antimicrobial activity and toxicity.

    PubMed

    Xavier, Nuno M; Goulart, Margarida; Neves, Ana; Justino, Jorge; Chambert, Stéphane; Rauter, Amélia P; Queneau, Yves

    2011-01-15

    The synthesis of a series of pyranoid derivatives comprising a conjugated carbonyl function and related triazole derivatives, structurally suitable for bioactivity evaluation, was achieved in few steps starting from readily available carboxymethyl glycoside lactones (CMGL). 3-Enopyranosid-2-uloses were generated by oxidation/elimination of tri-O-acylated 2-hydroxy pyranosides. Subsequent Wittig olefination provided stereoselectively 2-C-branched-chain conjugated dienepyranosides with (E)-configuration around the exocyclic double bond. A heterogeneous CuI/Amberlyst-catalyzed 'click' chemistry protocol was used to convert glycosides bearing a propargyl moiety into the corresponding 1,2,3-triazoles. These new molecules were screened for their in vitro antibacterial and antifungal activities and those containing conjugated carbonyl systems demonstrated the best efficacy. (N-Dodecylcarbamoyl)methyl enone glycerosides were the most active ones among the enones tested. The α-anomer displayed very strong activities against Bacillus cereus and Bacillus subtilis and strong activity toward Enterococcus faecalis and the fungal pathogen Penicillium aurantiogriseum. The corresponding β-anomer presented a very strong inhibitory effect against two fungal species (Aspergillus niger and P. aurantiogriseum). (N-Dodecyl-/N-propargyl/or N-benzylcarbamoyl)methyl dienepyranosides exhibited selectively a strong activity toward E. faecalis. Further acute toxicity evaluation indicated low toxic effect of the (N-dodecylcarbamoyl)methyl enone glyceroside α-anomer and of the carbamoylmethyl dienepyranosides N-protected with propargyl or benzyl groups.

  19. Efficient identification of flavones, flavanones and their glycosides in routine analysis via off-line combination of sensitive NMR and HPLC experiments.

    PubMed

    Blunder, Martina; Orthaber, Andreas; Bauer, Rudolf; Bucar, Franz; Kunert, Olaf

    2017-03-01

    We present a standardized, straightforward and efficient approach applicable in routine analysis of flavonoids combining sensitive NMR and HPLC experiments. The determination of the relative configuration of sugar moieties usually requires the acquisition of (13)C NMR shift values. We use a combination of HPLC and sensitive NMR experiments (1D-proton, 2D-HSQC) for the unique identification of known flavones, flavanones, flavonols and their glycosides. Owing to their broad range of polarity, we developed HPLC and UHPLC methods (H2O/MeOH/MeCN/HCOOH) which we applied and validated by analyzing 46 common flavones and flavanones and exemplified for four plant extracts. A searchable data base is provided with full data comprising complete proton and carbon resonance assignments, expansions of HSQC-spectra, HPLC parameters (retention time, relative retention factor), UV/Vis and mass spectral data of all compounds, which enables a rapid identification and routine analysis of flavones and flavanones from plant extracts and other products in nutrition and food chemistry.

  20. Identification of Unusual Phospholipid Fatty Acyl Compositions of Acanthamoeba castellanii

    PubMed Central

    Palusinska-Szysz, Marta; Kania, Magdalena; Turska-Szewczuk, Anna; Danikiewicz, Witold; Russa, Ryszard; Fuchs, Beate

    2014-01-01

    Acanthamoeba are opportunistic protozoan pathogens that may lead to sight-threatening keratitis and fatal granulomatous encephalitis. The successful prognosis requires early diagnosis and differentiation of pathogenic Acanthamoeba followed by aggressive treatment regimen. The plasma membrane of Acanthamoeba consists of 25% phospholipids (PL). The presence of C20 and, recently reported, 28- and 30-carbon fatty acyl residues is characteristic of amoeba PL. A detailed knowledge about this unusual PL composition could help to differentiate Acanthamoeba from other parasites, e.g. bacteria and develop more efficient treatment strategies. Therefore, the detailed PL composition of Acanthamoeba castellanii was investigated by 31P nuclear magnetic resonance spectroscopy, thin-layer chromatography, gas chromatography, high performance liquid chromatography and liquid chromatography-mass spectrometry. Normal and reversed phase liquid chromatography coupled with mass spectrometric detection was used for detailed characterization of the fatty acyl composition of each detected PL. The most abundant fatty acyl residues in each PL class were octadecanoyl (18∶0), octadecenoyl (18∶1 Δ9) and hexadecanoyl (16∶0). However, some selected PLs contained also very long fatty acyl chains: the presence of 28- and 30-carbon fatty acyl residues was confirmed in phosphatidylethanolamine (PE), phosphatidylserine, phosphatidic acid and cardiolipin. The majority of these fatty acyl residues were also identified in PE that resulted in the following composition: 28∶1/20∶2, 30∶2/18∶1, 28∶0/20∶2, 30∶2/20∶4 and 30∶3/20∶3. The PL of amoebae are significantly different in comparison to other cells: we describe here for the first time unusual, very long chain fatty acids with Δ5-unsaturation (30∶35,21,24) and 30∶221,24 localized exclusively in specific phospholipid classes of A. castellanii protozoa that could serve as specific biomarkers for the presence of these

  1. Sphingomyelin interfacial behavior: the impact of changing acyl chain composition.

    PubMed Central

    Li, X M; Smaby, J M; Momsen, M M; Brockman, H L; Brown, R E

    2000-01-01

    Sphingomyelins (SMs) containing homogeneous acyl chains with 12, 14, 16, 18, 24, or 26 carbons were synthesized and characterized using an automated Langmuir-type film balance. Surface pressure was monitored as a function of lipid molecular area at constant temperatures between 10 degrees C and 30 degrees C. SM containing lauroyl (12:0) acyl chains displayed only liquid-expanded behavior. Increasing the length of the saturated acyl chain (e.g., 14:0, 16:0, or 18:0) resulted in liquid-expanded to condensed two-dimensional phase transitions at many temperatures in the 10-30 degrees C range. Similar behavior was observed for SMs with lignoceroyl (24:0) or (cerotoyl) 26:0 acyl chains, but isotherms showed only condensed behavior at 10 and 15 degrees C. Insights into the physico-mechanical in-plane interactions occurring within the different SM phases and accompanying changes in SM phase state were provided by analyzing the interfacial area compressibility moduli. At similar surface pressures, SM fluid phases were less compressible than those of phosphatidylcholines with similar chain structures. The area per molecule and compressibility of SM condensed phases depended upon the length of the saturated acyl chain and upon spreading temperature. Spreading of SMs with very long saturated acyl chains at temperatures 30-35 degrees below T(m) resulted in condensed films with lower in-plane compressibilities, but consistently larger cross-sectional molecular areas than the condensed phases achieved by spreading at temperatures only 10-20 degrees below T(m). This behavior is discussed in terms of the enhancement of SM lateral aggregation by temperature reduction, a common approach used during domain isolation from biomembranes. PMID:10733971

  2. Glycosidation of Methanol with Ribose: An Interdisciplinary Undergraduate Laboratory Experiment

    ERIC Educational Resources Information Center

    Simon, Erin; Cook, Katie; Pritchard, Meredith R.; Stripe, Wayne; Bruch, Martha; Bendinskas, Kestutis

    2010-01-01

    This exercise provides students hands-on experience with the topics of glycosidation, hemiacetal and acetal formation, proton nuclear magnetic resonance ([superscript 1]H NMR) spectroscopy, and kinetic and thermodynamic product formation. In this laboratory experiment, the methyl acetal of ribose is synthesized, and the kinetic and thermodynamic…

  3. Two new indolopyridoquinazoline alkaloidal glycosides from Ranunculus ternatus.

    PubMed

    Zhang, Lin; Yang, Zhuang; Tian, Jing-Kui

    2007-08-01

    Two new indolopyridoquinazoline alkaloidal glycosides, 11-O-beta-D-glucopyranosyl rutaecarpine (ternatoside C) and 11-O-alpha-L-rhamnosyl-(1-->6)-beta-D-glucopyranosyl rutaecarpine (ternatoside D) were isolated from the roots of Ranunculus ternatus. Their structures were determined on the basis of spectroscopic and chemical methods.

  4. Spirostanol glycosides with hemostatic and antimicrobial activities from Trillium kamtschaticum.

    PubMed

    Chen, Yu; Ni, Wei; Yan, Huan; Qin, Xu-Jie; Khan, Afsar; Liu, Hui; Shu, Tong; Jin, Ling-Yu; Liu, Hai-Yang

    2016-11-01

    Ten spirostanol glycosides, trillikamtosides A-J, together with eleven known analogues, were isolated from the hemostatic fraction of the 75% aqueous EtOH extract of the whole herbs of Trillium kamtschaticum. Their structures were established by extensive spectroscopic data analysis and chemical methods. The aglycones of three of these compounds had unique 3β,17α-dihydroxy-spirostanes featuring a double bond between C-4 and C-5, while two others represent a rare class of spirostanol glycosides which possess a 5(6 → 7) abeo-steroidal aglycone. All the compounds were evaluated for their hemostatic and antimicrobial activities. Three of the spirostanol glycosides exhibited induced-platelet aggregation at a concentration of 300 μg/mL with maximal induced-platelet aggregation rates of 72%, 71%, and 62% in rabbits, respectively, and their EC50 values were 492.7, 203.3, and 109.8 μM. Five of the spirostanol glycosides showed an anti-Candida albicans effect with MIC values of 21.1, 10.6, 8.8, 21.6, and 11.0 μM, respectively.

  5. New glycosides of acetophenone derivatives and phenylpropanoids from Juniperus occidentalis.

    PubMed

    Inatomi, Yuka; Murata, Hiroko; Inada, Akira; Nakanishi, Tsutomu; Lang, Frank A; Murata, Jin; Iinuma, Munekazu

    2013-04-01

    New glycosides of seven acetophenone derivatives (1-7) and two phenylpropanoids (8, 9), named juniperosides III-XI, have been isolated from the MeOH extract of the leaves and stems of Juniperus occidentalis Hook. (Cupressaceae), together with eleven other known compounds. The structures of these compounds have been successfully elucidated using a variety of spectroscopic techniques.

  6. A New Flavanonol Glycoside from Adansonia digitata Roots.

    PubMed

    Chauhan, J S; Kumar, S; Chaturvedi, R

    1984-02-01

    A new flavanonol glycoside isolated from the roots of Adansonia digitata has been characterised as 3,7-dihydroxy flavan-4-one-5-O-beta- D-galactopyranosyl (1 --> 4)-beta- D-glucopyranoside on the basis of degradation, spectral and chemical studies.

  7. Three new hecogenin glycosides from fermented leaves of Agave americana.

    PubMed

    Jin, Jian-Ming; Liu, Xi-Kui; Yang, Chong-Ren

    2003-06-01

    Eight steroidal compounds, including three new hecogenin glycosides, agamenosides D-F, were isolated from the fermented leaves of Agave americana. The structures of the new steroidal saponins were elucidated by spectroscopic data and chemical methods. The activity of the isolated compounds on deformations of mycelia germinated from conidia of Pyricularia oaryzae P-2b was evaluated.

  8. Triterpenoid glycosides from the leaves of Meliosma henryi.

    PubMed

    Alabdul Magid, Abdulmagid; Morjani, Hamid; Harakat, Dominique; Madoulet, Claudie; Dumontet, Vincent; Lavaud, Catherine

    2015-01-01

    Seven triterpenoid glycosides, named meliosmosides A-G, were isolated from the leaves of Meliosma henryi Diels (Sabiaceae). Their structures were elucidated by different spectroscopic methods including 1D and 2D NMR experiments as well as HRESIMS analysis. Isolated compounds were evaluated for their cytotoxic activity against KB cell line.

  9. On the differences between ouabain and digitalis glycosides.

    PubMed

    Fuerstenwerth, Hauke

    2014-01-01

    Digoxin and digitoxin are widely used in the treatment of heart diseases. The exact mechanism of action of these drugs has remained an enigma. Ouabain has become the standard tool to investigate the mode of action of cardiotonic steroids, and results with ouabain are regarded as generally valid for all cardiac glycosides. However, there are marked differences between the effects of ouabain and digitalis glycosides. Ouabain has a different therapeutic profile from digitalis derivatives. Unlike digitalis glycosides, ouabain has a fast onset of action and stimulates myocardial metabolism. The inotropic effect of cardiotonic steroids is not related to inhibition of the Na-K-ATPase. Ouabain and digitalis derivatives develop their effects in different cellular spaces. Digitalis glycosides increase the intracellular calcium concentration by entering the cell interior and acting on the ryanodine receptors and by forming transmembrane calcium channels. Ouabain, by activation of the Na-K-ATPase from the extracellular side, triggers release of calcium from intracellular stores via signal transduction pathways and activates myocardial metabolism. These data no longer support the concept that all cardiotonic steroids exhibit their therapeutic effects by partial inhibition of the ion-pumping function of the Na-K-ATPase. Hence, it is suggested that this deeply rooted dogma be revised.

  10. 4'-Methoxyphenacyl-Assisted Synthesis of β-Kdo Glycosides.

    PubMed

    Mazur, Marcelina; Barycza, Barbara; Andriamboavonjy, Hanitra; Lavoie, Serge; Tamigney Kenfack, Marielle; Laroussarie, Anaïs; Blériot, Yves; Gauthier, Charles

    2016-11-18

    3-Deoxy-β-d-manno-oct-2-ulosonic acid (β-Kdo) glycosides are mainly found in capsular polysaccharides and extracellular exopolysaccharides from Gram-negative bacteria. These compounds have profound biological implications in immune response and act as virulence factors. We have developed a novel methodology for the stereoselective synthesis of β-Kdo glycosides via the use of a 4'-methoxyphenacyl (Phen) auxiliary group at the C1 position of a peracetylated β-Kdo thioglycoside. Under the promotion of NIS/AgOTf in acetonitrile, a series of Kdo glycosides was synthesized in good yield and β-selectivity while minimizing the formation of undesirable glycals. Stereoselectivity of the glycosylation was shown to be modulated by various factors such as promotor, solvent, anomeric ratio of donor, nature of acceptor, and Phen substitution. Chemoselective cleavage of the Phen group was performed under the action of Zn/HOAc. DFT calculations together with experimental results suggested that α-triflate and a six-membered α-spiroPhen are plausible intermediates of the reaction, accounting for the enhanced formation of β-Kdo glycosides. The developed methodology could be applied to the synthesis of β-Kdo-containing glycans from pathogenic bacteria.

  11. Structural revision of two flavanonol glycosides from Smilax glabra.

    PubMed

    Zhou, Xiang; Xu, Qiang; Li, Jian-Xin; Chen, Ting

    2009-05-01

    The structures of two flavanonol glycosides isolated from Smilax glabra, named smitilbin and neosmitilbin, have been revised to isoastilbin and neoastilbin, respectively. The revised structures were determined based on intensive studies of chemical interconversion, NMR spectroscopy, and X-ray crystallographic analysis. The latest NMR data were also summarized.

  12. Curation of characterized glycoside hydrolases of Fungal origin

    PubMed Central

    Murphy, Caitlin; Powlowski, Justin; Wu, Min; Butler, Greg; Tsang, Adrian

    2011-01-01

    Fungi produce a wide range of extracellular enzymes to break down plant cell walls, which are composed mainly of cellulose, lignin and hemicellulose. Among them are the glycoside hydrolases (GH), the largest and most diverse family of enzymes active on these substrates. To facilitate research and development of enzymes for the conversion of cell-wall polysaccharides into fermentable sugars, we have manually curated a comprehensive set of characterized fungal glycoside hydrolases. Characterized glycoside hydrolases were retrieved from protein and enzyme databases, as well as literature repositories. A total of 453 characterized glycoside hydrolases have been cataloged. They come from 131 different fungal species, most of which belong to the phylum Ascomycota. These enzymes represent 46 different GH activities and cover 44 of the 115 CAZy GH families. In addition to enzyme source and enzyme family, available biochemical properties such as temperature and pH optima, specific activity, kinetic parameters and substrate specificities were recorded. To simplify comparative studies, enzyme and species abbreviations have been standardized, Gene Ontology terms assigned and reference to supporting evidence provided. The annotated genes have been organized in a searchable, online database called mycoCLAP (Characterized Lignocellulose-Active Proteins of fungal origin). It is anticipated that this manually curated collection of biochemically characterized fungal proteins will be used to enhance functional annotation of novel GH genes. Database URL: http://mycoCLAP.fungalgenomics.ca/ PMID:21622642

  13. A new phenylpropanoid glycoside from Jasminum subtriplinerve Blume.

    PubMed

    Huong, Nguyen Thi Hong; Cu, Nguyen Khac Quynh; Quy, Trinh Van; Zidorn, Christian; Ganzera, Markus; Stuppner, Hermann

    2008-01-01

    From the ethyl acetate extract of the aerial parts of Jasminum subtriplinerve Blume (Oleaceae), 6'-O-menthiafoloylverbascoside (1), rutin (2), isoverbascoside (4), isooleoverbascoside (6), apiosylverbascoside (7), astragalin (9), isoquercitrin (10), and verbascoside (11) were isolated. Their structures were elucidated by extensive MS and NMR spectroscopy. Amongst 6'-O-menthiafoloylverbascoside (1) is a new phenylpropanoid glycoside.

  14. The cardiac glycoside-receptor system in the human heart.

    PubMed

    Erdmann, E; Brown, L

    1983-01-01

    Specific binding sites have been demonstrated to exist in the heart for several drugs and hormones such as beta-blocking agents, cardiac glycosides, catecholamines, insulin, glucagon and acetylcholine. The specific binding sites for cardiac glycosides in the human heart have certain properties which make it likely that they are the pharmacological receptors for the therapeutic and toxic actions of digitalis glycosides: they are located in the cell membrane and bind cardioactive steroids reversibly with high affinity: half-maximal receptor binding occurs at approximately 2 nM (approximately 1.5 ng/ml) for digoxin; potassium decreases receptor affinity, calcium increases it; specific binding of ouabain, digoxin or digitoxin is related to inhibition of (Na+ + K+)-ATPase activity--which is supposed to be the receptor enzyme for cardiac glycosides. Human left ventricle contains approximately 1.5 x 10(14) binding sites/g wet weight, right ventricle approximately 0.9 x 10(14). In disease the number of receptors may decrease (hypothyroid states, myocardial infarction) or increase (hyperthyroidism, chronic hypokalaemia). Certain drugs (such as phenytoin) or different temperatures or pH changes cause a change in digitalis-receptor affinity. Thus, the number of receptors and possibly their properties are subject to regulation in clinically relevant situations. Further investigations will probably reveal those pathophysiological states, which allow the explanation of toxicity or digitalis refractoriness.

  15. Quantum chemical study of penicillin: Reactions after acylation

    NASA Astrophysics Data System (ADS)

    Li, Rui; Feng, Dacheng; Zhu, Feng

    The density functional theory methods were used on the model molecules of penicillin to determine the possible reactions after their acylation on ?-lactamase, and the results were compared with sulbactam we have studied. The results show that, the acylated-enzyme tetrahedral intermediate can evolves with opening of ?-lactam ring as well as the thiazole ring; the thiazole ring-open products may be formed via ?-lactam ring-open product or from tetrahedral intermediate directly. Those products, in imine or enamine form, can tautomerize via hydrogen migration. In virtue of the water-assisted, their energy barriers are obviously reduced.

  16. Photochemistry and pharmacology of 9, 19-cyclolanostane glycosides isolated from genus Cimicifuga.

    PubMed

    Su, Yang; Chi, Wen-Cheng; Wu, Lun; Wang, Qiu-Hong; Kuang, Hai-Xue

    2016-10-01

    The constituents of Cimicifuga plants have been extensively investigated, and the principal metabolites are 9, 19-cyclolanostane triterpenoid glycosides, which often exhibit extensive pharmacological activities. 9, 19-Cyclolanostane triterpenoid glycosides are distributed widely in genus Cimicifuga rather than in other members of the Ranunculaceae family. So far, more than 140 cycloartane triterpene glycosides have been isolated from Cimicifuga spp.. The aim of this review was to summarize all 9, 19-cyclolanostane triterpenoid glycosides based on the available relevant scientific literatures from 2000 to 2014. Biological studies of cycloartane triterpene glycosides from Cimicifuga spp. are also discussed.

  17. Potentiation of luteolin cytotoxicity by flavonols fisetin and quercetin in human chronic lymphocytic leukemia cell lines.

    PubMed

    Sak, Katrin; Kasemaa, Kristi; Everaus, Hele

    2016-09-14

    Despite numerous studies chronic lymphocytic leukemia (CLL) still remains an incurable disease. Therefore, all new compounds and novel strategies which are able to eradicate CLL cells should be considered as valuable clues for a potential future remedy against this malignancy. In the present study, the cytotoxic profiles of natural flavonoids were described in two human CLL cell lines, HG-3 and EHEB, indicating the flavone luteolin as the most potent flavonoid with half-maximal inhibitory constants (IC50) of 37 μM and 26 μM, respectively. Luteolin significantly increased the apoptotic cell population in both cell lines by increasing the activities of caspases-3 and -9 and triggering the intrinsic apoptotic pathway. Two flavonols, fisetin and quercetin, were somewhat less efficient in suppressing cellular viability, whereas baicalein, chrysin, (+)-catechin and hesperetin exerted only a small or no response at doses as high as 100 μM. Both fisetin and quercetin were able to augment the cytotoxic activity of luteolin in both cell lines by reducing the IC50 values up to four fold. As a result of this, luteolin displayed cytotoxicity activity already at low micromolar concentrations that could potentially be physiologically achievable through oral ingestion. No other tested flavonoids were capable of sensitizing CLL cells to luteolin pointing to a specific binding of fisetin and quercetin to the cellular targets which interfere with the signaling pathways induced by luteolin. Although further molecular studies to unravel this potentiating mechanism are certainly needed, this phenomenon could contribute to future remedies for prevention and treatment of chronic lymphocytic leukemia.

  18. Flavonol-rich dark cocoa significantly decreases plasma endothelin-1 and improves cognition in urban children.

    PubMed

    Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Cross, Janet V; Engle, Randall; Aragón-Flores, Mariana; Gómez-Garza, Gilberto; Jewells, Valerie; Medina-Cortina, Humberto; Solorio, Edelmira; Chao, Chih-Kai; Zhu, Hongtu; Mukherjee, Partha S; Ferreira-Azevedo, Lara; Torres-Jardón, Ricardo; D'Angiulli, Amedeo

    2013-01-01

    Air pollution exposures are linked to systemic inflammation, cardiovascular and respiratory morbidity and mortality, neuroinflammation and neuropathology in young urbanites. In particular, most Mexico City Metropolitan Area (MCMA) children exhibit subtle cognitive deficits, and neuropathology studies show 40% of them exhibiting frontal tau hyperphosphorylation and 51% amyloid-β diffuse plaques (compared to 0% in low pollution control children). We assessed whether a short cocoa intervention can be effective in decreasing plasma endothelin 1 (ET-1) and/or inflammatory mediators in MCMA children. Thirty gram of dark cocoa with 680 mg of total flavonols were given daily for 10.11 ± 3.4 days (range 9-24 days) to 18 children (10.55 years, SD = 1.45; 11F/7M). Key metabolite ratios in frontal white matter and in hippocampus pre and during cocoa intervention were quantified by magnetic resonance spectroscopy. ET-1 significantly decreased after cocoa treatment (p = 0.0002). Fifteen children (83%) showed a marginally significant individual improvement in one or both of the applied simple short memory tasks. Endothelial dysfunction is a key feature of exposure to particulate matter (PM) and decreased endothelin-1 bioavailability is likely useful for brain function in the context of air pollution. Our findings suggest that cocoa interventions may be critical for early implementation of neuroprotection of highly exposed urban children. Multi-domain nutraceutical interventions could limit the risk for endothelial dysfunction, cerebral hypoperfusion, neuroinflammation, cognitive deficits, structural volumetric detrimental brain effects, and the early development of the neuropathological hallmarks of Alzheimer's and Parkinson's diseases.

  19. Flavonol-rich dark cocoa significantly decreases plasma endothelin-1 and improves cognition in urban children

    PubMed Central

    Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Cross, Janet V.; Engle, Randall; Aragón-Flores, Mariana; Gómez-Garza, Gilberto; Jewells, Valerie; Weili, Lin; Medina-Cortina, Humberto; Solorio, Edelmira; Chao, Chih-kai; Zhu, Hongtu; Mukherjee, Partha S.; Ferreira-Azevedo, Lara; Torres-Jardón, Ricardo; D'Angiulli, Amedeo

    2013-01-01

    Air pollution exposures are linked to systemic inflammation, cardiovascular and respiratory morbidity and mortality, neuroinflammation and neuropathology in young urbanites. In particular, most Mexico City Metropolitan Area (MCMA) children exhibit subtle cognitive deficits, and neuropathology studies show 40% of them exhibiting frontal tau hyperphosphorylation and 51% amyloid-β diffuse plaques (compared to 0% in low pollution control children). We assessed whether a short cocoa intervention can be effective in decreasing plasma endothelin 1 (ET-1) and/or inflammatory mediators in MCMA children. Thirty gram of dark cocoa with 680 mg of total flavonols were given daily for 10.11 ± 3.4 days (range 9–24 days) to 18 children (10.55 years, SD = 1.45; 11F/7M). Key metabolite ratios in frontal white matter and in hippocampus pre and during cocoa intervention were quantified by magnetic resonance spectroscopy. ET-1 significantly decreased after cocoa treatment (p = 0.0002). Fifteen children (83%) showed a marginally significant individual improvement in one or both of the applied simple short memory tasks. Endothelial dysfunction is a key feature of exposure to particulate matter (PM) and decreased endothelin-1 bioavailability is likely useful for brain function in the context of air pollution. Our findings suggest that cocoa interventions may be critical for early implementation of neuroprotection of highly exposed urban children. Multi-domain nutraceutical interventions could limit the risk for endothelial dysfunction, cerebral hypoperfusion, neuroinflammation, cognitive deficits, structural volumetric detrimental brain effects, and the early development of the neuropathological hallmarks of Alzheimer's and Parkinson's diseases. PMID:23986703

  20. Plant flavonol isorhamnetin attenuates chemically induced inflammatory bowel disease via a PXR-dependent pathway.

    PubMed

    Dou, Wei; Zhang, Jingjing; Li, Hao; Kortagere, Sandhya; Sun, Katherine; Ding, Lili; Ren, Gaiyan; Wang, Zhengtao; Mani, Sridhar

    2014-09-01

    Isorhamnetin is an O-methylated flavonol present in fruit and vegetables. We recently reported the identification of isorhamnetin as an activator of the human pregnane X receptor (PXR), a known target for abrogating inflammation in inflammatory bowel disease (IBD). The current study investigated the role of isorhamnetin as a putative mouse PXR activator in ameliorating chemically induced IBD. Using two different models (ulcerative colitis like and Crohn's disease like) of experimental IBD in mice, we demonstrated that isorhamnetin abrogated inflammation through inhibiting the activity of myeloperoxidase, the levels of TNF-α and IL-6, the mRNA expression of proinflammatory mediators (iNOS, ICAM-1, COX2, TNF-α, IL-2 and IL-6) and the phosphorylation of IκBα and NF-κB p65. PXR gene overexpression inhibited NF-κB luciferase activity, and the inhibition was potentiated by isorhamnetin treatment. PXR knockdown by siRNA demonstrated the necessity for PXR in isorhamnetin-mediated up-regulation of xenobiotic metabolism genes. Ligand pocket-filling mutants (S247W/C284W and S247W/C284W/S208W) of human PXR weakened the effect of isorhamnetin on PXR activation. Molecular docking studies and time-resolved fluorescence resonance energy transfer competitive binding assays confirmed the ligand (isorhamnetin)-binding affinity. These results clearly demonstrated the ameliorating effect of isorhamnetin on experimental IBD via PXR-mediated up-regulation of xenobiotic metabolism and down-regulation of NF-κB signaling. The novel findings may contribute to the effective utilization of isorhamnetin or its derivatives as a PXR ligand in the treatment of human IBD.

  1. Novel approach in LC-MS/MS using MRM to generate a full profile of acyl-CoAs: discovery of acyl-dephospho-CoAs[S

    PubMed Central

    Li, Qingling; Zhang, Shenghui; Berthiaume, Jessica M.; Simons, Brigitte; Zhang, Guo-Fang

    2014-01-01

    A metabolomic approach to selectively profile all acyl-CoAs was developed using a programmed multiple reaction monitoring (MRM) method in LC-MS/MS and was employed in the analysis of various rat organs. The programmed MRM method possessed 300 mass ion transitions with the mass difference of 507 between precursor ion (Q1) and product ion (Q3), and the precursor ion started from m/z 768 and progressively increased one mass unit at each step. Acyl-dephospho-CoAs resulting from the dephosphorylation of acyl-CoAs were identified by accurate MS and fragmentation. Acyl-dephospho-CoAs were also quantitatively scanned by the MRM method with the mass difference of 427 between Q1 and Q3 mass ions. Acyl-CoAs and dephospho-CoAs were assayed with limits of detection ranging from 2 to 133 nM. The accuracy of the method was demonstrated by assaying a range of concentrations of spiked acyl-CoAs with the results of 80–114%. The distribution of acyl-CoAs reflects the metabolic status of each organ. The physiological role of dephosphorylation of acyl-CoAs remains to be further characterized. The methodology described herein provides a novel strategy in metabolomic studies to quantitatively and qualitatively profile all potential acyl-CoAs and acyl-dephospho-CoAs. PMID:24367045

  2. Copper(II)/amine synergistically catalyzed enantioselective alkylation of cyclic N-acyl hemiaminals with aldehydes.

    PubMed

    Sun, Shutao; Mao, Ying; Lou, Hongxiang; Liu, Lei

    2015-07-07

    The first catalytic asymmetric alkylation of N-acyl quinoliniums with aldehydes has been described. A copper/amine synergistic catalytic system has been developed, allowing the addition of functionalized aldehydes to a wide range of electronically varied N-acyl quinoliniums in good yields with excellent enantiocontrol. The synergistic catalytic system was also effective for N-acyl dihydroisoquinoliniums and β-caboliniums, demonstrating the general applicability of the protocol in the enantioselective alkylation of diverse cyclic N-acyl hemiaminals.

  3. The Level of Circulating Octanoate Does Not Predict Ghrelin O-Acyl Transferase (GOAT)-Mediated Acylation of Ghrelin During Fasting

    PubMed Central

    Nikolayev, Alexander; Liu, Jianhua; Pezzoli, Suzan S.; Farhy, Leon S.; Patrie, James; Gaylinn, Bruce D.; Heiman, Mark; Thorner, Michael O.

    2015-01-01

    Background: Acyl-ghrelin is a 28-amino acid peptide released from the stomach. Ghrelin O-acyl transferase (GOAT) attaches an 8-carbon medium-chain fatty acid (MCFA) (octanoate) to serine 3 of ghrelin. This acylation is necessary for the activity of ghrelin. Animal data suggest that MCFAs provide substrate for GOAT and an increase in nutritional octanoate increases acyl-ghrelin. Objectives: To address the question of the source of substrate for acylation, we studied whether the decline in ghrelin acylation during fasting is associated with a decline in circulating MCFAs. Methods: Eight healthy young men (aged 18–28 years, body mass index range, 20.6–26.2 kg/m2) had blood drawn every 10 minutes for acyl- and desacyl-ghrelin and every hour for free fatty acids (FFAs) during the last 24 hours of a 61.5-hour fast and during a fed day. FFAs were measured by a highly sensitive liquid chromatography-mass spectroscopy method. Acyl- and desacyl-ghrelin were measured in an in-house assay; the results were published previously. Ghrelin acylation was assessed by the ratio of acyl-ghrelin to total ghrelin. Results: With the exception of MCFAs C8 and C10, all other FFAs, the MCFAs (C6 and C12), and the long-chain fatty acids (C14–C18) significantly increased with fasting (P < .05). There was no significant association between the fold change in ghrelin acylation and circulating FFAs. Conclusions: These results suggest that changes in circulating MCFAs are not linked to the decline in ghrelin acylation during fasting and support the hypothesis that acylation of ghrelin depends at least partially on the availability of gastroluminal MCFAs or the regulation of GOAT activity. PMID:25337923

  4. Extractability of Low Molecular Mass Flavanols and Flavonols from Red Grape Skins. Relationship to Cell Wall Composition at Different Ripeness Stages.

    PubMed

    Quijada-Morín, Natalia; Hernández-Hierro, José Miguel; Rivas-Gonzalo, Julián C; Escribano-Bailón, M Teresa

    2015-09-09

    Flavonol and flavan-3-ol extractabilities from red grape skins were evaluated in Tempranillo grapes harvested at different ripeness stages and with different soluble solid contents within each stage. Flavan-3-ol extractability is related to ripeness stage and also to cell wall composition, mainly to arabinogalactans (AG), mannans, rhamnogalacturonans-I (RG-I), homogalacturonans (HG), xyloglucans (XG), and total polysaccharides content, which are negatively correlated to flavan-3-ol extractability, whereas soluble solid content did not exert any influence on their extraction. Moreover, procyanidin extraction is more strongly related to cell wall composition than prodelphinidin extraction. Flavonol extractability was not influenced by insoluble material contents; although some cell wall components presented a relationship with flavonol extractability, the presence of AG and mannans would decrease total flavonol extractability, whereas protein is positively related to total and major flavonol compounds (i.e., quercetin and myricetin derivatives). The different behaviors observed between those two groups of polyphenol compounds could be due to different tissue and cellular location.

  5. A Cerulenin Insensitive Short Chain 3-Ketoacyl-Acyl Carrier Protein Synthase in Spinacia oleracea Leaves

    PubMed Central

    Jaworski, Jan G.; Clough, Richard C.; Barnum, Susan R.

    1989-01-01

    A cerulenin insensitive 3-ketoacyl-acyl carrier protein synthase has been assayed in extracts of spinach (Spinacia oleracea) leaf. The enzyme was active in the 40 to 80% ammonium sulfate precipitate of whole leaf homogenates and catalyzed the synthesis of acetoacetyl-acyl carrier protein. This condensation reaction was five-fold faster than acetyl-CoA:acyl carrier protein transacylase, and the initial rates of acyl-acyl carrier protein synthesis were independent of the presence of cerulenin. In the presence of fatty acid synthase cofactors and 100 micromolar cerulenin, the principal fatty acid product of de novo synthesis was butyric and hexanoic acids. Using conformationally sensitive native polyacrylamide gel electrophoresis for separation, malonyl-, acetyl-, butyryl-, hexanoyl, and long chain acyl-acyl carrier proteins could be detected by immunoblotting and autoradiography. In the presence of 100 micromolar cerulenin, the accumulation of butyryl- and hexanoyl-acyl carrier protein was observed, with no detectable long chain acyl-acyl carrier proteins or fatty acids being produced. In the absence of cerulenin, the long chain acyl-acyl carrier proteins also accumulated. Images Figure 2 Figure 3 PMID:16666765

  6. Dietary Intakes of Individual Flavanols and Flavonols Are Inversely Associated with Incident Type 2 Diabetes in European Populations123

    PubMed Central

    Zamora-Ros, Raul; Forouhi, Nita G.; Sharp, Stephen J.; González, Carlos A.; Buijsse, Brian; Guevara, Marcela; van der Schouw, Yvonne T.; Amiano, Pilar; Boeing, Heiner; Bredsdorff, Lea; Fagherazzi, Guy; Feskens, Edith J.; Franks, Paul W.; Grioni, Sara; Katzke, Verena; Key, Timothy J.; Khaw, Kay-Tee; Kühn, Tilman; Masala, Giovanna; Mattiello, Amalia; Molina-Montes, Esther; Nilsson, Peter M.; Overvad, Kim; Perquier, Florence; Redondo, M. Luisa; Ricceri, Fulvio; Rolandsson, Olov; Romieu, Isabelle; Roswall, Nina; Scalbert, Augustin; Schulze, Matthias; Slimani, Nadia; Spijkerman, Annemieke M. W.; Tjonneland, Anne; Tormo, Maria Jose; Touillaud, Marina; Tumino, Rosario; van der A, Daphne L.; van Woudenbergh, Geertruida J.; Langenberg, Claudia; Riboli, Elio; Wareham, Nicholas J.

    2014-01-01

    Dietary flavanols and flavonols, flavonoid subclasses, have been recently associated with a lower risk of type 2 diabetes (T2D) in Europe. Even within the same subclass, flavonoids may differ considerably in bioavailability and bioactivity. We aimed to examine the association between individual flavanol and flavonol intakes and risk of developing T2D across European countries. The European Prospective Investigation into Cancer and Nutrition (EPIC)–InterAct case-cohort study was conducted in 8 European countries across 26 study centers with 340,234 participants contributing 3.99 million person-years of follow-up, among whom 12,403 incident T2D cases were ascertained and a center-stratified subcohort of 16,154 individuals was defined. We estimated flavonoid intake at baseline from validated dietary questionnaires using a database developed from Phenol-Explorer and USDA databases. We used country-specific Prentice-weighted Cox regression models and random-effects meta-analysis methods to estimate HRs. Among the flavanol subclass, we observed significant inverse trends between intakes of all individual flavan-3-ol monomers and risk of T2D in multivariable models (all P-trend < 0.05). We also observed significant trends for the intakes of proanthocyanidin dimers (HR for the highest vs. the lowest quintile: 0.81; 95% CI: 0.71, 0.92; P-trend = 0.003) and trimers (HR: 0.91; 95% CI: 0.80, 1.04; P-trend = 0.07) but not for proanthocyanidins with a greater polymerization degree. Among the flavonol subclass, myricetin (HR: 0.77; 95% CI: 0.64, 0.93; P-trend = 0.001) was associated with a lower incidence of T2D. This large and heterogeneous European study showed inverse associations between all individual flavan-3-ol monomers, proanthocyanidins with a low polymerization degree, and the flavonol myricetin and incident T2D. These results suggest that individual flavonoids have different roles in the etiology of T2D. PMID:24368432

  7. Acyl migration kinetics of vegetable oil 1,2-diacylglycerols

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The acyl migration kinetics of long-chain 1,2-diacylglycerol (1,2-DAG) to form 1,3-diacylglycerol (1,3-DAG) over the temperature range of 25 to 80 degrees Celsius were examined using proton NMR spectroscopy. The 1,2-DAG mole fraction of 0.32 at equilibrium was found to be insensitive to temperature...

  8. One-Step Conversion of Methyl Ketones to Acyl Chlorides.

    PubMed

    Zaragoza, Florencio

    2015-10-16

    Treatment of aromatic and heteroaromatic methyl ketones with sulfur monochloride and catalytic amounts of pyridine in refluxing chlorobenzene leads to the formation of acyl chlorides. Both electron-rich and electron-poor aryl methyl ketones can be used as starting materials. The resulting C1-byproduct depends on the precise reaction conditions chosen.

  9. Lubricity characteristics of seed oils modified by acylation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemically modified seed oils via acylation of epoxidized and polyhydroxylated derivatives were investigated for their potential as candidates for lubrication. The native oil was preliminarily epoxidized and ring-opened in a one-pot reaction using formic acid-H2O2 followed by aqueous HCl treatment t...

  10. Mechanistic studies of malonic acid-mediated in situ acylation.

    PubMed

    Chandra, Koushik; Naoum, Johnny N; Roy, Tapta Kanchan; Gilon, Chaim; Gerber, R Benny; Friedler, Assaf

    2015-09-01

    We have previously introduced an easy to perform, cost-effective and highly efficient acetylation technique for solid phase synthesis (SPPS). Malonic acid is used as a precursor and the reaction proceeds via a reactive ketene that acetylates the target amine. Here we present a detailed mechanistic study of the malonic acid-mediated acylation. The influence of reaction conditions, peptide sequence and reagents was systematically studied. Our results show that the methodology can be successfully applied to different types of peptides and nonpeptidic molecules irrespective of their structure, sequence, or conformation. Using alkyl, phenyl, and benzyl malonic acid, we synthesized various acyl peptides with almost quantitative yields. The ketenes obtained from the different malonic acid derived precursors were characterized by in situ (1) H-NMR. The reaction proceeded in short reaction times and resulted in excellent yields when using uronium-based coupling agents, DIPEA as a base, DMF/DMSO/NMP as solvents, Rink amide/Wang/Merrifield resins, temperature of 20°C, pH 8-12 and 5 min preactivation at inert atmosphere. The reaction was unaffected by Lewis acids, transition metal ions, surfactants, or salt. DFT studies support the kinetically favorable concerted mechanism for CO2 and ketene formation that leads to the thermodynamically stable acylated products. We conclude that the malonic acid-mediated acylation is a general method applicable to various target molecules.

  11. Fluorescently labelled bovine acyl-CoA-binding protein acting as an acyl-CoA sensor: interaction with CoA and acyl-CoA esters and its use in measuring free acyl-CoA esters and non-esterified fatty acids.

    PubMed Central

    Wadum, Majken C T; Villadsen, Jens K; Feddersen, Søren; Møller, Rikke S; Neergaard, Thomas B F; Kragelund, Birthe B; Højrup, Peter; Faergeman, Nils J; Knudsen, Jens

    2002-01-01

    Long-chain acyl-CoA esters are key metabolites in lipid synthesis and beta-oxidation but, at the same time, are important regulators of intermediate metabolism, insulin secretion, vesicular trafficking and gene expression. Key tools in studying the regulatory functions of acyl-CoA esters are reliable methods for the determination of free acyl-CoA concentrations. No such method is presently available. In the present study, we describe the synthesis of two acyl-CoA sensors for measuring free acyl-CoA concentrations using acyl-CoA-binding protein as a scaffold. Met24 and Ala53 of bovine acyl-CoA-binding protein were replaced by cysteine residues, which were covalently modified with 6-bromoacetyl-2-dimethylaminonaphthalene to make the two fluorescent acyl-CoA indicators (FACIs) FACI-24 and FACI-53. FACI-24 and FACI-53 showed fluorescence emission maximum at 510 and 525 nm respectively, in the absence of ligand (excitation 387 nm). Titration of FACI-24 and FACI-53 with hexadecanoyl-CoA and dodecanoyl-CoA increased the fluorescence yield 5.5-and 4.7-fold at 460 and 495 nm respectively. FACI-24 exhibited a high, and similar increase in, fluorescence yield at 460 nm upon binding of C14-C20 saturated and unsaturated acyl-CoA esters. Both indicators bind long-chain (>C14) acyl-CoA esters with high specificity and affinity (K(d)=0.6-1.7 nM). FACI-53 showed a high fluorescence yield for C8-C12 acyl chains. It is shown that FACI-24 acts as a sensitive acyl-CoA sensor for measuring the concentration of free acyl-CoA, acyl-CoA synthetase activity and the concentrations of free fatty acids after conversion of the fatty acid into their respective acyl-CoA esters. PMID:12071849

  12. Ethanol Metabolism Modifies Hepatic Protein Acylation in Mice

    PubMed Central

    Fritz, Kristofer S.; Green, Michelle F.; Petersen, Dennis R.; Hirschey, Matthew D.

    2013-01-01

    Mitochondrial protein acetylation increases in response to chronic ethanol ingestion in mice, and is thought to reduce mitochondrial function and contribute to the pathogenesis of alcoholic liver disease. The mitochondrial deacetylase SIRT3 regulates the acetylation status of several mitochondrial proteins, including those involved in ethanol metabolism. The newly discovered desuccinylase activity of the mitochondrial sirtuin SIRT5 suggests that protein succinylation could be an important post-translational modification regulating mitochondrial metabolism. To assess the possible role of protein succinylation in ethanol metabolism, we surveyed hepatic sub-cellular protein fractions from mice fed a control or ethanol-supplemented diet for succinyl-lysine, as well as acetyl-, propionyl-, and butyryl-lysine post-translational modifications. We found mitochondrial protein propionylation increases, similar to mitochondrial protein acetylation. In contrast, mitochondrial protein succinylation is reduced. These mitochondrial protein modifications appear to be primarily driven by ethanol metabolism, and not by changes in mitochondrial sirtuin levels. Similar trends in acyl modifications were observed in the nucleus. However, comparatively fewer acyl modifications were observed in the cytoplasmic or the microsomal compartments, and were generally unchanged by ethanol metabolism. Using a mass spectrometry proteomics approach, we identified several candidate acetylated, propionylated, and succinylated proteins, which were enriched using antibodies against each modification. Additionally, we identified several acetyl and propionyl lysine residues on the same sites for a number of proteins and supports the idea of the overlapping nature of lysine-specific acylation. Thus, we show that novel post-translational modifications are present in hepatic mitochondrial, nuclear, cytoplasmic, and microsomal compartments and ethanol ingestion, and its associated metabolism, induce specific

  13. Post-veraison sunlight exposure induces MYB-mediated transcriptional regulation of anthocyanin and flavonol synthesis in berry skins of Vitis vinifera

    PubMed Central

    Matus, José Tomás; Loyola, Rodrigo; Vega, Andrea; Peña-Neira, Alvaro; Bordeu, Edmundo; Arce-Johnson, Patricio; Alcalde, José Antonio

    2009-01-01

    Anthocyanins, flavan-3-ols, and flavonols are the three major classes of flavonoid compounds found in grape berry tissues. Several viticultural practices increase flavonoid content in the fruit, but the underlying genetic mechanisms responsible for these changes have not been completely deciphered. The impact of post-veraison sunlight exposure on anthocyanin and flavonol accumulation in grape berry skin and its relation to the expression of different transcriptional regulators known to be involved in flavonoid synthesis was studied. Treatments consisting of removing or moving aside the basal leaves which shade berry clusters were applied. Shading did not affect sugar accumulation or gene expression of HEXOSE TRANSPORTER 1, although in the leaf removal treatment, these events were retarded during the first weeks of ripening. Flavonols were the most drastically reduced flavonoids following shading and leaf removal treatments, related to the reduced expression of FLAVONOL SYNTHASE 4 and its putative transcriptional regulator MYB12. Anthocyanin accumulation and the expression of CHS2, LDOX, OMT, UFGT, MYBA1, and MYB5a genes were also affected. Other regulatory genes were less affected or not affected at all by these treatments. Non-transcriptional control mechanisms for flavonoid synthesis are also suggested, especially during the initial stages of ripening. Although berries from the leaf removal treatment received more light than shaded fruits, malvidin-3-glucoside and total flavonol content was reduced compared with the treatment without leaf removal. This work reveals that flavonol-related gene expression responds rapidly to field changes in light levels, as shown by the treatment in which shaded fruits were exposed to light in the late stages of ripening. Taken together, this study establishes MYB-specific responsiveness for the effect of sun exposure and sugar transport on flavonoid synthesis. PMID:19129169

  14. Impact of Flavonols on Cardiometabolic Biomarkers: A Meta-Analysis of Randomized Controlled Human Trials to Explore the Role of Inter-Individual Variability

    PubMed Central

    Menezes, Regina; Rodriguez-Mateos, Ana; Kaltsatou, Antonia; González-Sarrías, Antonio; Greyling, Arno; Giannaki, Christoforos; Andres-Lacueva, Cristina; Milenkovic, Dragan; Gibney, Eileen R.; Dumont, Julie; Schär, Manuel; Garcia-Aloy, Mar; Palma-Duran, Susana Alejandra; Ruskovska, Tatjana; Maksimova, Viktorija; Combet, Emilie; Pinto, Paula

    2017-01-01

    Several epidemiological studies have linked flavonols with decreased risk of cardiovascular disease (CVD). However, some heterogeneity in the individual physiological responses to the consumption of these compounds has been identified. This meta-analysis aimed to study the effect of flavonol supplementation on biomarkers of CVD risk such as, blood lipids, blood pressure and plasma glucose, as well as factors affecting their inter-individual variability. Data from 18 human randomized controlled trials were pooled and the effect was estimated using fixed or random effects meta-analysis model and reported as difference in means (DM). Variability in the response of blood lipids to supplementation with flavonols was assessed by stratifying various population subgroups: age, sex, country, and health status. Results showed significant reductions in total cholesterol (DM = −0.10 mmol/L; 95% CI: −0.20, −0.01), LDL cholesterol (DM = −0.14 mmol/L; 95% CI: −0.21, 0.07), and triacylglycerol (DM = −0.10 mmol/L; 95% CI: −0.18, 0.03), and a significant increase in HDL cholesterol (DM = 0.05 mmol/L; 95% CI: 0.02, 0.07). A significant reduction was also observed in fasting plasma glucose (DM = −0.18 mmol/L; 95% CI: −0.29, −0.08), and in blood pressure (SBP: DM = −4.84 mmHg; 95% CI: −5.64, −4.04; DBP: DM = −3.32 mmHg; 95% CI: −4.09, −2.55). Subgroup analysis showed a more pronounced effect of flavonol intake in participants from Asian countries and in participants with diagnosed disease or dyslipidemia, compared to healthy and normal baseline values. In conclusion, flavonol consumption improved biomarkers of CVD risk, however, country of origin and health status may influence the effect of flavonol intake on blood lipid levels. PMID:28208791

  15. Activation of Exogenous Fatty Acids to Acyl-Acyl Carrier Protein Cannot Bypass FabI Inhibition in Neisseria*

    PubMed Central

    Yao, Jiangwei; Bruhn, David F.; Frank, Matthew W.; Lee, Richard E.; Rock, Charles O.

    2016-01-01

    Neisseria is a Gram-negative pathogen with phospholipids composed of straight chain saturated and monounsaturated fatty acids, the ability to incorporate exogenous fatty acids, and lipopolysaccharides that are not essential. The FabI inhibitor, AFN-1252, was deployed as a chemical biology tool to determine whether Neisseria can bypass the inhibition of fatty acid synthesis by incorporating exogenous fatty acids. Neisseria encodes a functional FabI that was potently inhibited by AFN-1252. AFN-1252 caused a dose-dependent inhibition of fatty acid synthesis in growing Neisseria, a delayed inhibition of growth phenotype, and minimal inhibition of DNA, RNA, and protein synthesis, showing that its mode of action is through inhibiting fatty acid synthesis. Isotopic fatty acid labeling experiments showed that Neisseria encodes the ability to incorporate exogenous fatty acids into its phospholipids by an acyl-acyl carrier protein-dependent pathway. However, AFN-1252 remained an effective antibacterial when Neisseria were supplemented with exogenous fatty acids. These results demonstrate that extracellular fatty acids are activated by an acyl-acyl carrier protein synthetase (AasN) and validate type II fatty acid synthesis (FabI) as a therapeutic target against Neisseria. PMID:26567338

  16. Rates of thrombin acylation and deacylation upon reaction with low molecular weight acylating agents, carbamylating agents and carbonylating agents.

    PubMed

    Brown, A D; Powers, J C

    1995-08-01

    Acylated derivatives of thrombin have been made using low molecular weight acylating agents, carbamylating agents and carbonylating agents. The compounds used to acylate the active site serine include isatoic anhydrides, benzoxazinones, benzylisocyanate, N-(benzylcarbonyloxy)succinimide and p-(dimethylamino)benzoylimidazolide. The rates of acylation and deacylation were determined. The best overall inhibitors of thrombin are 2-ethoxy-4H-3,1-benzoxazin-4-one, isatoic anhydride and tert-butyl-2,4-dioxo-2H-3,1-benzoxazine-1(4H)-acetate, which have k2/Ki values of 52,700 M-1s-1, 48,900 M-1s-1 and 5400 M-1s-1, respectively. The carbamyl derivative of thrombin formed with benzylisocyanate had the slowest rate of deacylation (2.3 x 10(-7) s-1), while the ester derivative formed with 2-(N,N-dimethylamino)methylimino-4H-3,1-benzoxazin-4-one had the fastest rate of deacylation (1.9 x 10(-4) s-1).

  17. Palmitoyl-acyl carrier protein (ACP) thioesterase and the evolutionary origin of plant acyl-ACP thioesterases.

    PubMed Central

    Jones, A; Davies, H M; Voelker, T A

    1995-01-01

    Acyl-acyl carrier protein (ACP) thioesterases play an essential role in chain termination during de novo fatty acid synthesis and in the channeling of carbon flux between the two lipid biosynthesis pathways in plants. We have discovered that there are two distinct but related thioesterase gene classes in higher plants, termed FatA and FatB, whose evolutionary divergence appears to be ancient. FatA encodes the already described 18:1-ACP thioesterase. In contrast, FatB representatives encode thioesterases preferring acyl-ACPs having saturated acyl groups. We unexpectedly obtained a 16:0-ACP thioesterase cDNA from Cuphea hookeriana seed, which accumulate predominantly 8:0 and 10:0. The 16:0 thioesterase transcripts were found in non-seed tissues, and expression in transgenic Brassica napus led to the production of a 16:0-rich oil. We present evidence that this type of FatB gene is ancient and ubiquitous in plants and that specialized plant medium-chain thioesterases have evolved independently from such enzymes several times during angiosperm evolution. Also, the ubiquitous 18:1-ACP thioesterase appears to be a derivative of a 16:0 thioesterase. PMID:7734968

  18. Sweet antibiotics - the role of glycosidic residues in antibiotic and antitumor activity and their randomization.

    PubMed

    Kren, Vladimír; Rezanka, Tomás

    2008-08-01

    A large number of antibiotics are glycosides. In numerous cases the glycosidic residues are crucial to their activity; sometimes, glycosylation only improves their pharmacokinetic parameters. Recent developments in molecular glycobiology have improved our understanding of aglycone vs. glycoside activities and made it possible to develop new, more active or more effective glycodrugs based on these findings - a very illustrative recent example is vancomycin. The majority of attention has been devoted to glycosidic antibiotics including their past, present, and probably future position in antimicrobial therapy. The role of the glycosidic residue in the biological activity of glycosidic antibiotics, and the attendant targeting and antibiotic selectivity mediated by glycone and aglycone in antibiotics some antitumor agents is discussed here in detail. Chemical and enzymatic modifications of aglycones in antibiotics, including their synthesis, are demonstrated on various examples, with particular emphasis on the role of specific and mutant glycosyltransferases and glycorandomization in the preparation of these compounds. The last section of this review describes and explains the interactions of the glycone moiety of the antibiotics with DNA and especially the design and structure-activity relationship of glycosidic antibiotics, including their classification based on their aglycone and glycosidic moiety. The new enzymatic methodology 'glycorandomization' enabled the preparation of glycoside libraries and opened up new ways to prepare optimized or entirely novel glycoside antibiotics.

  19. Production of a Brassica napus low-molecular mass acyl-coenzyme A-binding protein in Arabidopsis alters the acyl-coenzyme A pool and acyl composition of oil in seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low-molecular mass (10 kD) cytosolic acyl-coenzyme A-binding protein (ACBP) has a substantial influence over fatty acid (FA) composition in oilseeds, possibly via an effect on the partitioning of acyl groups between elongation and desaturation pathways. Previously, we demonstrated that the expressio...

  20. Flavonol Glucoside and Antioxidant Enzyme Biosynthesis Affected by Mycorrhizal Fungi in Various Cultivars of Onion (Allium cepa L.).

    PubMed

    Mollavali, Mohanna; Bolandnazar, Saheb Ali; Schwarz, Dietmar; Rohn, Sascha; Riehle, Peer; Zaare Nahandi, Fariborz

    2016-01-13

    The objective of this study was to investigate the impact of mycorrhizal symbiosis on qualitative characteristics of onion (Allium cepa L.). For this reason, five onion cultivars with different scale color and three different strains of arbuscular mycorrhizal fungi (Diversispora versiformis, Rhizophagus intraradices, Funneliformis mosseae) were used. Red cultivars, mainly 'Red Azar-shahr', showed the highest content in vitamin C, flavonols, and antioxidant enzymes. Mycorrhizal inoculation increased total phenolic, pyruvic acid, and vitamin C of onion plants. Considerable increase was observed in quercetin-4'-O-monoglucoside and isorhamnetin-4'-O-monoglucoside content in plants inoculated with Diversispora versiformis, but quercetin-3,4'-O-diglucoside was not significantly influenced. Analyses for phenylalanine ammonia-lyase (PAL) and antioxiodant enzyme activities such as polyphenol oxidase (PPO), catalase (CAT), and peroxidase (POD) revealed that all except PPO were enhanced by mycorrhizal inoculation. Overall, these findings suggested that mycorrhizal inoculation influenced biosynthesis of flavonol glucosides and antioxidant enzymes by increasing nutrient uptake or by induction of the plant defense system.

  1. Flavonol content and biometrical traits as a tool for the characterization of "Cipolla di Giarratana": a traditional Sicilian onion landrace.

    PubMed

    Riggi, Ezio; Avola, Giovanni; Siracusa, Laura; Ruberto, Giuseppe

    2013-10-15

    "Cipolla di Giarratana", a locally cultivated white onion landrace, is listed as an item in the 'List of Traditional Agro-food Products' of the Italian Department for Agriculture and itemised as 'slow food presidium' by the Slow Food Foundation. Ten local accessions were investigated for their biomorphological and biochemical characteristics in five experimental locations. High-performance liquid chromatography coupled with diode array detection and electron spray-mass spectrometry (HPLC/DAD/ESI-MS) was used to identify the phenolic profile and quantify phenolic content in bulbs: quercetin, quercetin 3,4' di-O-glucoside and quercetin 4'-O-glucoside were detected as major components. The 'Cipolla di Giarratana' landrace is characterised by a high bulb weight (436g) and high diameter (11cm). The total flavonols content ranged between 68 and 408mgkg(-1) bulb fresh weight in nine of the 10 collected accessions. The opportunity of considering flavonol patterns as chemotaxonomic descriptors in order to characterise onion germplasm is also discussed.

  2. New pregnane and phenolic glycosides from Solenostemma argel.

    PubMed

    Ounaissia, Karima; Pertuit, David; Mitaine-Offer, Anne-Claire; Miyamoto, Tomofumi; Tanaka, Chiaki; Delemasure, Stéphanie; Dutartre, Patrick; Smati, Dalila; Lacaille-Dubois, Marie-Aleth

    2016-10-01

    From the aerial parts, pericarps and roots of Solenostemma argel, three new pregnane glycosides (1-3) with two known ones and a new phenolic glycoside (4) have been isolated. Their structures were established by extensive 1D - and 2D NMR and mass spectroscopic analysis. The cytotoxicity of all compounds was evaluated against two human tumor cell lines (SW 480, MCF-7), but none of them was active in the concentration range 0.9-59.0μM. Compounds 2 and the known argeloside F at non toxic concentrations for the PBMCs (27.3μM and 27.6μM, respectively) significantly decreased the Il-1β production by LPS-stimulated PBMCs. All isolated compounds showed a significant antioxidant potential with ORAC values in the concentration range 3481-9617μmoleq. Trolox/100g.

  3. Four new neuroprotective iridoid glycosides from Scrophularia buergeriana roots.

    PubMed

    Kim, So Ra; Lee, Ki Yong; Koo, Kyung Ah; Sung, Sang Hyun; Lee, Na-Gyong; Kim, Jinwoong; Kim, Young Choong

    2002-11-01

    Four new iridoid glycosides were isolated from a 90% MeOH extract of Scrophularia buergeriana roots and characterized as 8-O-E-p-methoxycinnamoylharpagide (1), 8-O-Z-p-methoxycinnamoylharpagide (2), 6'-O-E-p-methoxycinnamoylharpagide (3), and 6'-O-Z-p-methoxycinnamoylharpagide (4), respectively. In addition, three known iridoids were identified as E-harpagoside (5), Z-harpagoside (6), and harpagide (7). Compounds 1-7 significantly attenuated glutamate-induced neurotoxicity when added to primary cultures of rat cortical cells at concentrations ranging from 100 nM to 10 microM. The results obtained indicate that the iridoid glycosides isolated from S. buergeriana have significant protective effects against glutamate-induced neurodegeneration in primary cultures of rat cortical neurons.

  4. Synthetic Glycosides and Glycoconjugates of Low Molecular Weight Natural Products.

    PubMed

    Grynkiewicz, G; Szeja, W

    2016-01-01

    Enzymatically controlled transfer of saccharide moieties constitutes a fundamental biological process, essential for both primary and secondary metabolism. Natural products, including countless glycosides, with a rich tradition of use in ethnopharmacology, remain a prime source of inspiration for medicinal chemistry and molecular pharmacology, but their availability from biological sources is usually scarce, hampering attempts at application for new drug discovery and development. Chemical glycosylation on the other hand, although continuously undergoing sophisticated mechanistic studies, has nevertheless already matured as a set of methods which are able to provide substantial amounts of pure chemical entities: natural glycosides, as well as their congeners and mimics, necessary for the study of biological activity in quality assurance systems and required for drug development by pharmaceutical regulations. The paper presents a review of natural products and their analogues glycosylation, in a set of arbitrary selected examples, supplemented with comments on general advances in chemical glycosylation methodology and their applicability for particular categories of secondary metabolites.

  5. New terpenoid glycosides obtained from Rosmarinus officinalis L. aerial parts.

    PubMed

    Zhang, Yi; Adelakun, Tiwalade Adegoke; Qu, Lu; Li, Xiaoxia; Li, Jian; Han, Lifeng; Wang, Tao

    2014-12-01

    Five new terpenoid glycosides, named as officinoterpenosides A₁ (1), A₂ (2), B (3), C (4), and D (5), together with 11 known ones, (1S,4S,5S)-5-exo-hydrocamphor 5-O-β-D-glucopyranoside (6), isorosmanol (7), rosmanol (8), 7-methoxyrosmanol (9), epirosmanol (10), ursolic acid (11), micromeric acid (12), oleanolic acid (13), niga-ichigoside F₁ (14), glucosyl tormentate (15), and asteryunnanoside B (16), were obtained from the aerial parts of Rosmarinus officinalis L. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Among the new ones, 1 and 2, 3 and 4 are diterpenoid and triterpenoid glycosides, respectively; and 5 is a normonoterpenoid. For the known ones, 6 was isolated from the Rosmarinus genus first, and 15, 16 were obtained from this species for the first time.

  6. Coumarins of Matricaria chamomilla L.: aglycones and glycosides.

    PubMed

    Petruľová-Poracká, Veronika; Repčák, Miroslav; Vilková, Mária; Imrich, Ján

    2013-11-01

    The identity and quantity of coumarin-like compounds in leaves and anthodia of Matricaria chamomilla L. were studied by LC-DAD and NMR. So far, two monosubstituted coumarins, herniarin and umbelliferone, and two herniarin precursors were identified therein. In this paper, two other coumarin glycosides and one aglycone were confirmed. Skimmin (umbelliferone-7-O-β-d-glucoside), daphnin (daphnetin-7-O-β-d-glucoside) and daphnetin (7,8-dihydroxycoumarin) were found for the first time in diploid and tetraploid leaves and anthodia of M. chamomilla L. Daphnetin is known as a strong sensitizer, so this compound and its glycosidic derivative can contribute to the allergic potential of chamomile. Commercial chamomile preparations were tested for their presence.

  7. Capillary electrophoresis of neutral carbohydrates: mono-, oligosaccharides, glycosides.

    PubMed

    Campa, Cristiana; Rossi, Marco

    2008-01-01

    This chapter reports an overview of the recent advances in the analysis of neutral sugars by capillary electrophoresis (CE); furthermore, some relevant reviews and research articles in the field are tabulated. Comparison of CE with chromatography is also presented, with special attention to separation efficiency and sensitivity. The main routes aimed at pretreatment and CE analysis of uncharged mono-, oligosaccharides, and glycosides are described. Representative examples of such procedures are reported in detail, upon describing robust methodologies for the study of (1) neutral mono- and oligosaccharides derivatized by reductive amination and by formation of glycosylamines; (2) underivatized mono- and di-saccharides analyzed using highly alkaline buffers; and (3) anomeric couples of glycosides separated using borate-based buffers.

  8. Two new pregnane glycoside diesters from Caralluma russeliana.

    PubMed

    Abdel-Mogib, Mamdouh; Raghib, Hanaa M

    2013-01-01

    Two new pregnane glycoside diesters, 1 and 2, in addition to two triterpenoids, 3 and 4, and two sterols, 5 and 6 were isolated and identified from Caralluma russeliana (family Asclepiadaceae). The new pregnane glycosides, 14β-benzoyloxy-15β-isovaleroyloxy-16α-hydroxypregn-20-on-3-O-[β-D-3-O-methyl-6-deoxyoleandrosopyranosyl-(1 → 4)-β-D-cymaropyranosyl-(1 → 4)-β-D-cymaropyranoside] (1) and 14β-isovaleroyloxy-15β-benzoyloxy-16α-hydroxypregn-20-on-3-O-[β-D-3-O-methyl-6-deoxyoleandrosopyranosyl-(1 → 4)-β-D-cymaropyranosyl-(1 → 4)-β-D-cymaropyranoside] (2), are different from those isolated previously from the same species in the sugar moiety, in being diester, in being 20-one and in being 5,6 saturated by hydrogen. The isolated compounds were identified on the basis of spectral data.

  9. Acylation of Glucagon-Like Peptide-2: Interaction with Lipid Membranes and In Vitro Intestinal Permeability

    PubMed Central

    Trier, Sofie; Linderoth, Lars; Bjerregaard, Simon; Andresen, Thomas Lars; Rahbek, Ulrik Lytt

    2014-01-01

    Background Acylation of peptide drugs with fatty acid chains has proven beneficial for prolonging systemic circulation as well as increasing enzymatic stability without disrupting biological potency. Acylation has furthermore been shown to increase interactions with the lipid membranes of mammalian cells. The extent to which such interactions hinder or benefit delivery of acylated peptide drugs across cellular barriers such as the intestinal epithelia is currently unknown. The present study investigates the effect of acylating peptide drugs from a drug delivery perspective. Purpose We hypothesize that the membrane interaction is an important parameter for intestinal translocation, which may be used to optimize the acylation chain length for intestinal permeation. This work aims to characterize acylated analogues of the intestinotrophic Glucagon-like peptide-2 by systematically increasing acyl chain length, in order to elucidate its influence on membrane interaction and intestinal cell translocation in vitro. Results Peptide self-association and binding to both model lipid and cell membranes was found to increase gradually with acyl chain length, whereas translocation across Caco-2 cells depended non-linearly on chain length. Short and medium acyl chains increased translocation compared to the native peptide, but long chain acylation displayed no improvement in translocation. Co-administration of a paracellular absorption enhancer was found to increase translocation irrespective of acyl chain length, whereas a transcellular enhancer displayed increased synergy with the long chain acylation. Conclusions These results show that membrane interactions play a prominent role during intestinal translocation of an acylated peptide. Acylation benefits permeation for shorter and medium chains due to increased membrane interactions, however, for longer chains insertion in the membrane becomes dominant and hinders translocation, i.e. the peptides get ‘stuck’ in the cell

  10. Two new lignan glycosides from the fruits of Pyrus ussuriensis.

    PubMed

    Zhao, Ze-Qing; Su, Yan-Fang; Yang, Fei; Gao, Xiu-Mei; Li, Tian-Xiang

    2016-12-01

    Two new lignan glycosides, ussuriensislignan A (1) and ussuriensislignan B (2), together with seventeen known compounds (3-19), were isolated from the fruits of Pyrus ussuriensis. Their structures were determined by various spectroscopic methods. This is the first report of the isolation of lignans (compounds 1-3) from the genus Pyrus, and compounds 3-6, 12-16 were reported from Pyrus for the first time.

  11. A new lignan glycoside from the rhizomes of Imperata cylindrica.

    PubMed

    Lee, Dae-Young; Han, Kyung-Min; Song, Myoung-Chong; Lee, Do-Gyeong; Rho, Yeong-Deok; Baek, Nam-In

    2008-01-01

    A new lignan glycoside, 6-acetyl-1-[1,3-(4,4'-dihydroxy-3,3'-dimethoxy-beta-truxinyl)-beta-d-fructofuranosyl]-alpha-d-glucopyranoside (1), named impecyloside, was isolated from the rhizomes of Imperata cylindrica. The structure of the compound was determined by spectroscopic data including FABMS, UV, IR, 1H NMR and 13C NMR (DEPT) and 2D NMR (COSY, HSQC, HMBC).

  12. Two new monoterpenoid glycosides from Mentha spicata L.

    PubMed

    Zheng, Jian; Wu, Li-Jun; Zheng, Lu; Wu, Bin; Song, Ai-Hua

    2003-03-01

    Two new monoterpenoid glycosides, spicatoside A and spicatoside B, were isolated from the whole herbs of Mentha spicata L. which have anti-inflammatory and hemostatic activities. Their structures have been determined on the basis of spectral and chemical analysis. They are (+)-5-[1-(beta-D-glucopyranosyloxymethyl)ethenyl]-2-methyl-2-cyclohexen-1-one (1), and (-)-5-[[2-(beta-D-glucopyranosyloxy)-1-hydroxy-l-methyl]ethyl]-2-methyl-2-cyclohexen-1-one (2).

  13. New phenolic glycosides from the seeds of Cucurbita moschata.

    PubMed

    Li, Fa-Sheng; Dou, De-Qiang; Xu, Liang; Chi, Xiao-Feng; Kang, Ting-Guo; Kuang, Hai-Xue

    2009-07-01

    Two new phenolic glycosides were isolated from the seeds of Cucurbita moschata. Their structures were elucidated as (2-hydroxy)phenylcarbinyl 5-O-benzoyl-beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoside (1) and 4-beta-D-(glucopyranosyl hydroxymethyl)phenyl 5-O-benzoyl-beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoside (2) on the basis of spectroscopic analysis and chemical evidence.

  14. Antifungal activity of steroidal glycosides from Yucca gloriosa L.

    PubMed

    Favel, A; Kemertelidze, E; Benidze, M; Fallague, K; Regli, P

    2005-02-01

    The antifungal activity of a crude steroidal glycoside extract from Yucca gloriosa flowers, named alexin, was investigated in vitro against a panel of human pathogenic fungi, yeasts as well as dermatophytes and filamentous species. The minimal inhibitory concentration (MIC) was determined by an agar dilution method. Alexin had a broad spectrum of antifungal activity, found to reside entirely in the spirostanoid fraction. The major tigogenyl glycosides, yuccaloeside B and yuccaloeside C, exhibited MICs between 0.39 and 6.25 microg[sol ]mL for all the tested yeast strains except for two (C. lusitaniae and C. kefyr). They were also active against several clinical Candida isolates known to be resistant to the usual antifungal agents. The MICs for the dermatophytes were between 0.78 and 12.5 microg[sol ]mL. The most sensitive filamentous species was A. fumigatus (MIC = 1.56 microg[sol ]mL). For most of the strains, the MICs of both glycosides were similar to those of the reference antifungal agent.

  15. Enzymatic Biosynthesis of Novel Resveratrol Glucoside and Glycoside Derivatives

    PubMed Central

    Pandey, Ramesh Prasad; Parajuli, Prakash; Shin, Ju Yong; Lee, Jisun; Lee, Seul; Hong, Young-Soo; Park, Yong Il; Kim, Joong Su

    2014-01-01

    A UDP glucosyltransferase from Bacillus licheniformis was overexpressed, purified, and incubated with nucleotide diphosphate (NDP) d- and l-sugars to produce glucose, galactose, 2-deoxyglucose, viosamine, rhamnose, and fucose sugar-conjugated resveratrol glycosides. Significantly higher (90%) bioconversion of resveratrol was achieved with α-d-glucose as the sugar donor to produce four different glucosides of resveratrol: resveratrol 3-O-β-d-glucoside, resveratrol 4′-O-β-d-glucoside, resveratrol 3,5-O-β-d-diglucoside, and resveratrol 3,5,4′-O-β-d-triglucoside. The conversion rates and numbers of products formed were found to vary with the other NDP sugar donors. Resveratrol 3-O-β-d-2-deoxyglucoside and resveratrol 3,5-O-β-d-di-2-deoxyglucoside were found to be produced using TDP-2-deoxyglucose as a donor; however, the monoglycosides resveratrol 4′-O-β-d-galactoside, resveratrol 4′-O-β-d-viosaminoside, resveratrol 3-O-β-l-rhamnoside, and resveratrol 3-O-β-l-fucoside were produced from the respective sugar donors. Altogether, 10 diverse glycoside derivatives of the medically important resveratrol were generated, demonstrating the capacity of YjiC to produce structurally diverse resveratrol glycosides. PMID:25239890

  16. Minor diterpene glycosides from the leaves of Stevia rebaudiana.

    PubMed

    Ibrahim, Mohamed A; Rodenburg, Douglas L; Alves, Kamilla; Fronczek, Frank R; McChesney, James D; Wu, Chongming; Nettles, Brian J; Venkataraman, Sylesh K; Jaksch, Frank

    2014-05-23

    Two new diterpene glycosides in addition to five known glycosides have been isolated from a commercial extract of the leaves of Stevia rebaudiana. Compound 1 (rebaudioside KA) was shown to be 13-[(O-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid 2-O-β-d-glucopyranosyl-β-d-glucopyranosyl ester and compound 2, 12-α-[(2-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid β-d-glucopyranosyl ester. Five additional known compounds were identified, rebaudioside E, rebaudioside M, rebaudioside N, rebaudioside O, and stevioside, respectively. Enzymatic hydrolysis of stevioside afforded the known ent-kaurane aglycone 13-hydroxy-ent-kaur-16-en-19-oic acid (steviol) (3). The isolated metabolite 1 possesses the ent-kaurane aglycone steviol (3), while compound 2 represents the first example of the isomeric diterpene 12-α-hydroxy-ent-kaur-16-en-19-oic acid existing as a glycoside in S. rebaudiana. The structures of the isolated metabolites 1 and 2 were determined based on comprehensive 1D- and 2D-NMR (COSY, HSQC, and HMBC) studies. A high-quality crystal of compound 3 has formed, which allowed the acquisition of X-ray diffraction data that confirmed its structure. The structural similarities between the new metabolites and the commercially available stevioside sweeteners suggest the newly isolated metabolites should be examined for their organoleptic properties. Accordingly rebaudiosides E, M, N, O, and KA have been isolated in greater than gram quantities.

  17. Modification of the substrate specificity of an acyl-acyl carrier protein thioesterase by protein engineering.

    PubMed

    Yuan, L; Voelker, T A; Hawkins, D J

    1995-11-07

    The plant acyl-acyl carrier protein (ACP) thioesterases (TEs) are of biochemical interest because of their roles in fatty acid synthesis and their utilities in the bioengineering of plant seed oils. When the FatB1 cDNA encoding a 12:0-ACP TE (Uc FatB1) from California bay, Umbellularia californica (Uc) was expressed in Escherichia coli and in developing oilseeds of the plants Arabidopsis thaliana and Brassica napus, large amounts of laurate (12:0) and small amounts of myristate (14:0) were accumulated. We have isolated a TE cDNA from camphor (Cinnamomum camphorum) (Cc) seeds that shares 92% amino acid identity with Uc FatB1. This TE, Cc FatB1, mainly hydrolyzes 14:0-ACP as shown by E. coli expression. We have investigated the roles of the N- and C-terminal regions in determining substrate specificity by constructing two chimeric enzymes, in which the N-terminal portion of one protein is fused to the C-terminal portion of the other. Our results show that the C-terminal two-thirds of the protein is critical for the specificity. By site-directed mutagenesis, we have replaced several amino acids in Uc FatB1 by using the Cc FatB1 sequence as a guide. A double mutant, which changes Met-197 to an Arg and Arg-199 to a His (M197R/R199H), turns Uc FatB1 into a 12:0/14:0 TE with equal preference for both substrates. Another mutation, T231K, by itself does not effect the specificity. However, when it is combined with the double mutant to generate a triple mutant (M197R/R199H/T231K), Uc FatB1 is converted to a 14:0-ACP TE. Expression of the double-mutant cDNA in E. coli K27, a strain deficient in fatty acid degradation, results in accumulation of similar amounts of 12:0 and 14:0. Meanwhile the E. coli expressing the triple-mutant cDNA produces predominantly 14:0 with very small amounts of 12:0. Kinetic studies indicate that both wild-type Uc FatB1 and the triple mutant have similar values of Km,app with respect to 14:0-ACP. Inhibitory studies also show that 12:0-ACP is a good

  18. A comparison of flavonoid glycosides by electrospray tandem mass spectrometry

    NASA Astrophysics Data System (ADS)

    March, Raymond E.; Lewars, Errol G.; Stadey, Christopher J.; Miao, Xiu-Sheng; Zhao, Xiaoming; Metcalfe, Chris D.

    2006-01-01

    A comparison is presented of product ion mass spectra of protonated and deprotonated molecules of kaempferol-3-O-glucoside, quercitin-3-O-glucoside (isoquercitrin), quercitin-3-O-galactoside (hyperoin), apigenin-7-O-glucoside, luteolin-7-O-glucoside, genistein-7-O-glucoside, naringenin-7-O-glucoside (prunin), luteolin-4'-O-glucoside, luteolin-6-C-glucoside (homoorientin, known also as isoorientin), apigenin-8-C-glucoside (vitexin), and luteolin-8-C-glucoside (orientin) together with the product ion mass spectrum of deprotonated kaempferol-7-O-glucoside. All isomeric ions were distinguishable on the basis of their product ion mass spectra. For protonated 3-O-, 7-O-, and 4'-O-glycosides at a collision energy of 46-47 eV, homolytic cleavage of the O-glycosidic bond yielded aglycon Y+ ions, whereas in deprotonated 3-O-, 7-O-, and 4'-O-glycosides, heterolytic and homolytic cleavage of the O-glycosidic bond yielded radical aglycon (Y-H)- and aglycon (Y-) ions. In each case, fragmentation of either the glycan or the aglycon or both was observed. For 6-C- and 8-C-glycosides at a collision energy of 46-47 eV, fragmentation was restricted almost exclusively to the glycan. For luteolin-6-C-glucoside, the integrity of the aglycon structure is preserved at the expense of the glycan for which some 30 fragmentations were observed. Breakdown curves were determined as a function of collision energy for protonated and deprotonated luteolin-6-C-glucoside. An attempt has been made to rationalize the product ion mass spectra derived from C-O- and C-C-luteolin glucosides in terms of computed structures that indicate significant intramolecular hydrogen bonding and rotation of the B-ring to form a coplanar luteolin structure. It is proposed that protonated and deprotonated luteolin-6-C-glucoside may afford examples of cooperative interactive bonding that plays a major role in directing fragmentation.

  19. Annotation and comparative analysis of the glycoside hydrolase genes in Brachypodium distachyon

    SciTech Connect

    Tyler, Ludmila; Bragg, Jennifer; Wu, Jiajie; Yang, Xiaohan; Tuskan, Gerald A; Vogel, John

    2010-01-01

    Background Glycoside hydrolases cleave the bond between a carbohydrate and another carbohydrate, a protein, lipid or other moiety. Genes encoding glycoside hydrolases are found in a wide range of organisms, from archea to animals, and are relatively abundant in plant genomes. In plants, these enzymes are involved in diverse processes, including starch metabolism, defense, and cell-wall remodeling. Glycoside hydrolase genes have been previously cataloged for Oryza sativa (rice), the model dicotyledonous plant Arabidopsis thaliana, and the fast-growing tree Populus trichocarpa (poplar). To improve our understanding of glycoside hydrolases in plants generally and in grasses specifically, we annotated the glycoside hydrolase genes in the grasses Brachypodium distachyon (an emerging monocotyledonous model) and Sorghum bicolor (sorghum). We then compared the glycoside hydrolases across species, both at the whole-genome level and at the level of individual glycoside hydrolase families. Results We identified 356 glycoside hydrolase genes in Brachypodium and 404 in sorghum. The corresponding proteins fell into the same 34 families that are represented in rice, Arabidopsis, and poplar, helping to define a glycoside hydrolase family profile which may be common to flowering plants. Examination of individual glycoside hydrolase familes (GH5, GH13, GH18, GH19, GH28, and GH51) revealed both similarities and distinctions between monocots and dicots, as well as between species. Shared evolutionary histories appear to be modified by lineage-specific expansions or deletions. Within families, the Brachypodium and sorghum proteins generally cluster with those from other monocots. Conclusions This work provides the foundation for further comparative and functional analyses of plant glycoside hydrolases. Defining the Brachypodium glycoside hydrolases sets the stage for Brachypodium to be a monocot model for investigations of these enzymes and their diverse roles in planta. Insights

  20. [S-Acyl derivatives of thiosalicylamides having antifungal activity. II].

    PubMed

    Mazza, M; Modena, T; Montanari, L; Pavanetto, F

    1978-07-01

    Some S-acyl derivatives of N-alkylthiosalicylamides [Table I: substances (I leads to XXXI)] were prepared and tested for antifungal activity. The substances, most of which had not been previously reported, were prepared by condensation of 2-mercapto-N-alkylbenzamides with suitable acylating agents. The antifungal activity of the compounds was tested in vitro against Candida albicans and Trichophyton mentagrophytes. For some compounds the was tested activity against the above strains fungicidal, Candida tropicalis and Saccharomyces cerevisiae. Many of the compounds proved to have high antifungal activity comparable with that of Clotrimazol. The results extended knowledge on the structure-antifungal activity relationships of this class of compounds. The compounds with the highest antifungal activity were: 2-acetylmercapto-N,n-heptylbenzamide (XXVIII); 2-acetylmercapto-5-Cl-N,n-propylbenzamide (XIV); 2-acetylmercapto-N,n-octylbenzamide (XXXI); 2-acetylmercapto-N,n-pentylbenzamide (XXV); 2-acetylmercapto-N,n-hexylbenzamide (XXVII).

  1. Metabolic Glycoengineering with N-Acyl Side Chain Modified Mannosamines.

    PubMed

    Wratil, Paul R; Horstkorte, Rüdiger; Reutter, Werner

    2016-08-08

    In metabolic glycoengineering (MGE), cells or animals are treated with unnatural derivatives of monosaccharides. After entering the cytosol, these sugar analogues are metabolized and subsequently expressed on newly synthesized glycoconjugates. The feasibility of MGE was first discovered for sialylated glycans, by using N-acyl-modified mannosamines as precursor molecules for unnatural sialic acids. Prerequisite is the promiscuity of the enzymes of the Roseman-Warren biosynthetic pathway. These enzymes were shown to tolerate specific modifications of the N-acyl side chain of mannosamine analogues, for example, elongation by one or more methylene groups (aliphatic modifications) or by insertion of reactive groups (bioorthogonal modifications). Unnatural sialic acids are incorporated into glycoconjugates of cells and organs. MGE has intriguing biological consequences for treated cells (aliphatic MGE) and offers the opportunity to visualize the topography and dynamics of sialylated glycans in vitro, ex vivo, and in vivo (bioorthogonal MGE).

  2. Three new alkaloids and three new phenolic glycosides from Liparis odorata.

    PubMed

    Jiang, Piao; Liu, Hongdong; Xu, Xianghong; Liu, Bo; Zhang, Dongming; Lai, Xuewen; Zhu, Genghua; Xu, Peng; Li, Bin

    2015-12-01

    Three new alkaloids, liparis alkaloid A (1), B (2), C (3), and three new phenolic glycosides, liparis glycoside H (4), I (5), J (6), together with three known phenolic glycosides (7-9) were isolated from the whole plant of Liparis odorata. Their structures were characterized on the basis of extensive 1D-, 2D-NMR and HR-ESI-MS experiments. In addition, compounds 1-3 revealed hypolipidemic effects in the in vitro bioassays, and the ability to inhibit LPS-induced NO production of these isolated phenolic glycosides (4-9) was also evaluated.

  3. Glycosides from marine sponges (Porifera, Demospongiae): structures, taxonomical distribution, biological activities and biological roles.

    PubMed

    Kalinin, Vladimir I; Ivanchina, Natalia V; Krasokhin, Vladimir B; Makarieva, Tatyana N; Stonik, Valentin A

    2012-08-01

    Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed.

  4. Selective separation of flavonoid glycosides in Dalbergia odorifera by matrix solid-phase dispersion using titania.

    PubMed

    Xu, Lingyan; Shi, Hui; Liang, Tu; Feng, Jiatao; Jin, Yu; Ke, Yanxiong; Liang, Xinmiao

    2011-06-01

    Dalbergia odorifera contains high concentrations of flavonoid aglycones and trace flavonoid glycosides. In this study, trace flavonoid glycosides were separated from D. odorifera by titania with matrix solid-phase dispersion (MSPD). Before the MSPD experiment, four standards, including two isoflavone glycosides (genistin and formononetin-8-C-apiosyl (1-6)-glucoside) and their aglycones (genistein and formononetin), were used to compare their retention on a titania column. The effect of acetonitrile concentration and pH on their retention was investigated and a conclusion was drawn that high acetonitrile concentration and pH lead to the greatest difference in the retention of flavonoid as glycosides and aglycones. Besides hydrophilic interaction and ligand-exchange interaction may exist between sugar moiety of flavonoid glycoside and titania, so that flavonoid glycosides have stronger retention than that of aglycones. Based on the chromatographic rule of flavonoid as glycosides and aglycones on the titania column, the MSPD method was optimized to elute high concentration flavonoid aglycones first with 90% acetonitrile and 10% water containing 100 mM ammonium acetate buffer, and then to elute trace flavonoid glycosides with 20% acetonitrile and 80% water containing 1% trifluoroacetate (TFA). Isolated flavonoid glycosides were further analyzed by UPLC-MS/MS, and their fragmentation in MS(2) showed they are C-glycosyl flavonoids.

  5. Tandem mass spectrometric fragmentation patterns of known and new steviol glycosides with structure proposals.

    PubMed

    Zimmermann, Benno F

    2011-06-15

    Stevia rebaudiana contains several steviol glycosides that have a sweet flavor. They are up to 450 times sweeter than sucrose, but some have an undesirable aftertaste. Up to 2010, ten different steviol glycosides have been described from the leaves or purified extracts of S. rebaudiana. In this paper, the tandem mass spectrometric fragmentation patterns of these ten compounds are compiled, along with a scheme for structural elucidation. This scheme is then applied to 12 steviol glycosides that have not yet been described. The proposed structures of five steviol glycosides have been confirmed by other authors.

  6. Thiourea-Catalyzed Aminolysis of N-acyl Homoserine Lactones

    DTIC Science & Technology

    2013-01-01

    of N-acyl homoserine lactones (AHLs), molecules integral to bacterial quorum sensing . The catalysts afford rate enhancement of up to 10 times the...SUBJECT TERMS quorum sensing Michael A. Bertucci, Stephen J. Lee, Michel R. Gagné University of North Carolina - Chapel Hill Office of Sponsored... quorum sensing . The catalysts afford rate enhancement of up to 10 times the control in CD3CN. Mild catalysis in other polar aprotic solvents is

  7. Antinociceptive property of new 4-acyl-arylhydrazone pyrazole compounds.

    PubMed

    Matheus, M E; Oliveira, L F; Freitas, A C; Carvalho, A M; Barreiro, E J

    1991-01-01

    A series of new 4-acyl-arylhydrazone pyrazole compounds were tested for antinociceptive activity using the inhibition of abdominal contortions induced by acetylcholine (4 mg/kg, ip) in the mouse. Dipyrone was used for comparison of the antinociceptive potency of the compounds being tested. All drugs were administered po in saline (dipyrone) or in propylene glycol (4-acyl-arylhydrazones). The maximum response induced by dipyrone (86% inhibition) was assigned an efficacy index of 1.0. Although none of the compounds had an efficacy index greater than 1.0, all three reached 1.0. The two most potent compounds, W1d and W1g, which also had an efficacy similar to that of dipyrone, contain a p-N(CH3)2 and m-OH,p-OCH3 group in the aromatic ring of the acyl-hydrazone, respectively. W1d presented the lowest antinociceptive ED50 in the series (1.41 mg/kg) and was eleven times more potent than dipyrone (ED50 = 15.80 mg/kg). Other substitutions at the para position had lower potency than W1d. The present results indicate that the introduction of a group at the para position of the acyl-arylhydrazone ring increases the antinociceptive activity of these compounds to provide compounds of the same efficacy but greater potency than dipyrone to which these new compounds are structurally related. Other assays of nociceptive activity are being used to characterize the mechanism of action of the potential new drugs.

  8. Acylation type determines ghrelin's effects on energy homeostasis in rodents.

    PubMed

    Heppner, Kristy M; Chaudhary, Nilika; Müller, Timo D; Kirchner, Henriette; Habegger, Kirk M; Ottaway, Nickki; Smiley, David L; Dimarchi, Richard; Hofmann, Susanna M; Woods, Stephen C; Sivertsen, Bjørn; Holst, Birgitte; Pfluger, Paul T; Perez-Tilve, Diego; Tschöp, Matthias H

    2012-10-01

    Ghrelin is a gastrointestinal polypeptide that acts through the ghrelin receptor (GHSR) to promote food intake and increase adiposity. Activation of GHSR requires the presence of a fatty-acid (FA) side chain on amino acid residue serine 3 of the ghrelin molecule. However, little is known about the role that the type of FA used for acylation plays in the biological action of ghrelin. We therefore evaluated a series of differentially acylated peptides to determine whether alterations in length or stability of the FA side chain have an impact on the ability of ghrelin to activate GHSR in vitro or to differentially alter food intake, body weight, and body composition in vivo. Fatty acids principally available in the diet (such as palmitate C16) and therefore representing potential substrates for the ghrelin-activating enzyme ghrelin O-acyltransferase (GOAT) were used for dose-, time-, and administration/route-dependent effects of ghrelin on food intake, body weight, and body composition in rats and mice. Our data demonstrate that altering the length of the FA side chain of ghrelin results in the differential activation of GHSR. Additionally, we found that acylation of ghrelin with a long-chain FA (C16) delays the acute central stimulation of food intake. Lastly, we found that, depending on acylation length, systemic and central chronic actions of ghrelin on adiposity can be enhanced or reduced. Together our data suggest that modification of the FA side-chain length can be a novel approach to modulate the efficacy of pharmacologically administered ghrelin.

  9. Glycosyltransferases from oat (Avena) implicated in the acylation of avenacins.

    PubMed

    Owatworakit, Amorn; Townsend, Belinda; Louveau, Thomas; Jenner, Helen; Rejzek, Martin; Hughes, Richard K; Saalbach, Gerhard; Qi, Xiaoquan; Bakht, Saleha; Roy, Abhijeet Deb; Mugford, Sam T; Goss, Rebecca J M; Field, Robert A; Osbourn, Anne

    2013-02-08

    Plants produce a huge array of specialized metabolites that have important functions in defense against biotic and abiotic stresses. Many of these compounds are glycosylated by family 1 glycosyltransferases (GTs). Oats (Avena spp.) make root-derived antimicrobial triterpenes (avenacins) that provide protection against soil-borne diseases. The ability to synthesize avenacins has evolved since the divergence of oats from other cereals and grasses. The major avenacin, A-1, is acylated with N-methylanthranilic acid. Previously, we have cloned and characterized three genes for avenacin synthesis (for the triterpene synthase SAD1, a triterpene-modifying cytochrome P450 SAD2, and the serine carboxypeptidase-like acyl transferase SAD7), which form part of a biosynthetic gene cluster. Here, we identify a fourth member of this gene cluster encoding a GT belonging to clade L of family 1 (UGT74H5), and show that this enzyme is an N-methylanthranilic acid O-glucosyltransferase implicated in the synthesis of avenacin A-1. Two other closely related family 1 GTs (UGT74H6 and UGT74H7) are also expressed in oat roots. One of these (UGT74H6) is able to glucosylate both N-methylanthranilic acid and benzoic acid, whereas the function of the other (UGT74H7) remains unknown. Our investigations indicate that UGT74H5 is likely to be key for the generation of the activated acyl donor used by SAD7 in the synthesis of the major avenacin, A-1, whereas UGT74H6 may contribute to the synthesis of other forms of avenacin that are acylated with benzoic acid.

  10. Six new acylated anthocyanins from red radish (Raphanus sativus).

    PubMed

    Tamura, Satoru; Tsuji, Kouji; Yongzhen, Piao; Ohnishi-Kameyama, Mayumi; Murakami, Nobutoshi

    2010-09-01

    Six new acylated anthocyanins (1-6) were isolated along with the three known congeners (7-9) from the fresh roots of red radishes (Raphanus sativus L.) cultivated by our group. Their chemical structures were elucidated by spectroscopic properties. Among the six new anthocyanins, the five constituents (1, 2, 4-6) were shown to contain the malonyl function at 6-OH in the glucopyranosyl residue linked to C-5 in the pelargonidin nucleus.

  11. A new cytotoxic acylated apigenin glucoside from Phyllanthus emblica L.

    PubMed

    El-Desouky, S K; Ryu, Shi Young; Kim, Young-Kyoon

    2008-01-10

    A new acylated apigenin glucoside (apigenin-7-O-(6''-butyryl-beta-glucopyranoside) (1) was isolated from the methanolic extract of the leaves of Phyllanthus emblica L. (Euphorbiaceae) together with the known compounds; gallic acid (2), methyl gallate (3), 1,2,3,4,6-penta-O-galloylglucose (4) and luteolin-4'-O-neohesperiodoside (5). Their chemical structures were elucidated on the basis of spectroscopic studies ((1)H NMR, (13)C NMR, DEPT, HSQC, HMBC).

  12. Antioxidant and antiatherogenic properties of phenolic acid and flavonol fractions of fruits of 'Amari' and 'Hallawi' date (Phoenix dactylifera L.) varieties.

    PubMed

    Borochov-Neori, Hamutal; Judeinstein, Sylvie; Greenberg, Amnon; Volkova, Nina; Rosenblat, Mira; Aviram, Michael

    2015-04-01

    Date (Phoenix dactylifera L.) fruit phenolic-acid or flavonol fractions were examined in vitro for antioxidant and antiatherogenic properties. Two fractions of each subgroup were prepared from two date varieties, 'Amari' and 'Hallawi', by solid phase extraction on C18. The fractions were analyzed for phenolics composition by RP-HPLC and tested for ferric-reducing antioxidant power, free radical scavenging capacity, inhibition of Cu(2+)-induced LDL oxidation, and enhancement of HDL-mediated cholesterol efflux from macrophages. All four fractions exhibited variable capacities to reduce ferric ions, scavenge radicals, and inhibit LDL oxidation. Flavonol fractions were considerably better inhibitors of LDL oxidation compared to phenolic acid fractions, with IC50's of 9-31 nmol GAE mL(-1) compared to 85-116 nmol GAE mL(-1), respectively. Only the flavonol fractions stimulated cholesterol removal from macrophages. Within each subgroup, the levels of all the activities varied with fraction composition. The results demonstrated strong structure-activity relationships for date phenolics and identified date flavonols as potential antiatherogenic bioactives.

  13. Genetic resources of the functional food, teramnus labialis (L.f.) spreng for improving seed number, flavonol content, oil %, and fatty acid compositions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Teramnus labialis is used as food in India and has potential to be used as a functional food vegetable in the U.S.A. Photoperiod-sensitive T. labialis accessions were grown in the greenhouse from 2010 to 2011 and evaluated for flavonol content, oil %, and fatty acid compositions. Significant variati...

  14. MYB12 and MYB22 play essential roles in proanthocyanidin and flavonol synthesis in red-fleshed apple (Malus sieversii f. niedzwetzkyana).

    PubMed

    Wang, Nan; Xu, Haifeng; Jiang, Shenghui; Zhang, Zongying; Lu, Ninglin; Qiu, Huarong; Qu, Changzhi; Wang, Yicheng; Wu, Shujing; Chen, Xuesen

    2017-04-01

    Flavonoids are major polyphenol compounds in plant secondary metabolism. Wild red-fleshed apples (Malus sieversii f. niedzwetzkyana) are an excellent resource because of their much high flavonoid content than cultivated apples. In this work, R6R6, R6R1 and R1R1 genotypes were identified in an F1 segregating population of M. sieversii f. niedzwetzkyana. Significant differences in flavonoid composition and content were detected among the three genotypes by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry analysis. Furthermore, two putative flavonoid-related genes encoding R2R3-MYB transcription factors, designated MYB12 and MYB22, were cloned and characterized. The expression patterns of MYB12 and MYB22 directly correlated with those of leucoanthocyanidin reductase and flavonol synthase, respectively. Their roles in flavonoid biosynthesis were identified by overexpression in apple callus and ectopic expression in Arabidopsis. MYB12 expression in the Arabidopsis TT2 mutant complemented its proanthocyanidin-deficient phenotype. Likewise, MYB22 expression in an Arabidopsis triple mutant complemented its flavonol-deficient phenotype. MYB12 could interact with bHLH3 and bHLH33 and played an essential role in proanthocyanidin synthesis. MYB22 was found to activate flavonol pathways by combining directly with the flavonol synthase promoter. Our findings provide a valuable perspective on flavonoid synthesis and provide a basis for breeding elite functional apples with a high flavonoid content.

  15. Metabolism of acyl-lipids in Chlamydomonas reinhardtii.

    PubMed

    Li-Beisson, Yonghua; Beisson, Fred; Riekhof, Wayne

    2015-05-01

    Microalgae are emerging platforms for production of a suite of compounds targeting several markets, including food, nutraceuticals, green chemicals, and biofuels. Many of these products, such as biodiesel or polyunsaturated fatty acids (PUFAs), derive from lipid metabolism. A general picture of lipid metabolism in microalgae has been deduced from well characterized pathways of fungi and land plants, but recent advances in molecular and genetic analyses of microalgae have uncovered unique features, pointing out the necessity to study lipid metabolism in microalgae themselves. In the past 10 years, in addition to its traditional role as a model for photosynthetic and flagellar motility processes, Chlamydomonas reinhardtii has emerged as a model organism to study lipid metabolism in green microalgae. Here, after summarizing data on total fatty acid composition, distribution of acyl-lipid classes, and major acyl-lipid molecular species found in C. reinhardtii, we review the current knowledge on the known or putative steps for fatty acid synthesis, glycerolipid desaturation and assembly, membrane lipid turnover, and oil remobilization. A list of characterized or putative enzymes for the major steps of acyl-lipid metabolism in C. reinhardtii is included, and subcellular localizations and phenotypes of associated mutants are discussed. Biogenesis and composition of Chlamydomonas lipid droplets and the potential importance of lipolytic processes in increasing cellular oil content are also highlighted.

  16. Phylogenetic and experimental characterization of an acyl-ACP thioesterase family reveals significant diversity in enzymatic specificity and activity

    PubMed Central

    2011-01-01

    Background Acyl-acyl carrier protein thioesterases (acyl-ACP TEs) catalyze the hydrolysis of the thioester bond that links the acyl chain to the sulfhydryl group of the phosphopantetheine prosthetic group of ACP. This reaction terminates acyl chain elongation of fatty acid biosynthesis, and in plant seeds it is the biochemical determinant of the fatty acid compositions of storage lipids. Results To explore acyl-ACP TE diversity and to identify novel acyl ACP-TEs, 31 acyl-ACP TEs from wide-ranging phylogenetic sources were characterized to ascertain their in vivo activities and substrate specificities. These acyl-ACP TEs were chosen by two different approaches: 1) 24 TEs were selected from public databases on the basis of phylogenetic analysis and fatty acid profile knowledge of their source organisms; and 2) seven TEs were molecularly cloned from oil palm (Elaeis guineensis), coconut (Cocos nucifera) and Cuphea viscosissima, organisms that produce medium-chain and short-chain fatty acids in their seeds. The in vivo substrate specificities of the acyl-ACP TEs were determined in E. coli. Based on their specificities, these enzymes were clustered into three classes: 1) Class I acyl-ACP TEs act primarily on 14- and 16-carbon acyl-ACP substrates; 2) Class II acyl-ACP TEs have broad substrate specificities, with major activities toward 8- and 14-carbon acyl-ACP substrates; and 3) Class III acyl-ACP TEs act predominantly on 8-carbon acyl-ACPs. Several novel acyl-ACP TEs act on short-chain and unsaturated acyl-ACP or 3-ketoacyl-ACP substrates, indicating the diversity of enzymatic specificity in this enzyme family. Conclusion These acyl-ACP TEs can potentially be used to diversify the fatty acid biosynthesis pathway to produce novel fatty acids. PMID:21831316

  17. Plant Microsomal Phospholipid Acyl Hydrolases Have Selectivities for Uncommon Fatty Acids.

    PubMed Central

    Stahl, U.; Banas, A.; Stymne, S.

    1995-01-01

    Developing endosperms and embryos accumulating triacylglycerols rich in caproyl (decanoyl) groups (i.e. developing embryos of Cuphea procumbens and Ulmus glabra) had microsomal acyl hydrolases with high selectivities toward phosphatidylcholine with this acyl group. Similarly, membranes from Euphorbia lagascae and Ricinus communis endosperms, which accumulate triacylglycerols with vernoleate (12-epoxy-octadeca-9-enoate) and ricinoleate (12-hydroxy-octadeca-9-enoate), respectively, had acyl hydrolases that selectively removed their respective oxygenated acyl group from the phospholipids. The activities toward phospholipid substrates with epoxy, hydroxy, and medium-chain acyl groups varied greatly between microsomal preparations from different plant species. Epoxidated and hydroxylated acyl groups in sn-1 and sn-2 positions of phosphatidylcholine and in sn-1-lysophosphatidylcholine were hydrolyzed to a similar extent, whereas the hydrolysis of caproyl groups was highly dependent on the positional localization. PMID:12228415

  18. Direct nonchromatographic assay for 1-acyl-sn-glycerol-3-phosphate acyltransferase

    SciTech Connect

    Rajasekharan, R.; Ray, T.K.; Cronan, J.E. Jr.

    1988-09-01

    1-Acyl-sn-glycerol-3-phosphate acyltransferase (also called lysophosphatidic acid acyltransferase) which catalyzes the acylation of 1-acyl-sn-glycerol-3-phosphate to phosphatidic acid is generally assayed by the use of a radioactive substrate followed by a time-consuming chromatographic separation of substrate and product. We report a direct and highly sensitive nonchromatographic assay for this enzyme based on the ability of Escherichia coli alkaline phosphatase to dephosphorylate 1-acyl-sn-glycerol-3-phosphate but not phosphatidic acid. This selective hydrolysis coupled with the use of /sup 32/P-labeled 1-acyl-sn-glycerol-3-phosphate as substrate permits measurement of the product, /sup 32/P-labeled phosphatidic acid by solvent extraction or precipitation. We also report a series of enzymatic reactions for the efficient conversion of /sup 32/Pi to /sup 32/P-labeled 1-acyl-sn-glycerol-3-phosphate.

  19. Characterization of Lipid A Variants by Energy-Resolved Mass Spectrometry: Impact of Acyl Chains

    NASA Astrophysics Data System (ADS)

    Crittenden, Christopher M.; Akin, Lucas D.; Morrison, Lindsay J.; Trent, M. Stephen; Brodbelt, Jennifer S.

    2016-12-01

    Lipid A molecules consist of a diglucosamine sugar core with a number of appended acyl chains that vary in their length and connectivity. Because of the challenging nature of characterizing these molecules and differentiating between isomeric species, an energy-resolved MS/MS strategy was undertaken to track the fragmentation trends and map genealogies of product ions originating from consecutive cleavages of acyl chains. Generalizations were developed based on the number and locations of the primary and secondary acyl chains as well as variations in preferential cleavages arising from the location of the phosphate groups. Secondary acyl chain cleavage occurs most readily for lipid A species at the 3' position, followed by primary acyl chain fragmentation at both the 3' and 3 positions. In the instances of bisphosphorylated lipid A variants, phosphate loss occurs readily in conjunction with the most favorable primary and secondary acyl chain cleavages.

  20. A novel insulin mimetic vanadium-flavonol complex: synthesis, characterization and in vivo evaluation in STZ-induced rats.

    PubMed

    Pillai, Subramanian Iyyam; Subramanian, Sorimuthu Pillai; Kandaswamy, Muthusamy

    2013-05-01

    Since 1985, when Heyliger et al., first demonstrated a serendipitous discovery that oral administration of 0.8 mg/ml of sodium orthovanadate in drinking water to streptozotocin-induced diabetic rats resulted in normoglycemia, numerous extensive studies have been pursued on the anti-diabetic and insulinomimetic actions of vanadium. The acceptance of vanadium compounds as promising therapeutic antidiabetic agents has been slowed due to the concern for chronic toxicity associated with vanadium accumulation. In order to circumvent the toxic effects of vanadium, we have taken up a combinational approach wherein a novel vanadium-flavonol complex was synthesized, characterized and its toxic as well as insulin mimetic potential was evaluated in STZ-induced experimental diabetes in rats. The results indicate that the complex is non-toxic and possess anti-diabetic activity.

  1. [Full-length cDNA cloning of flavonol synthase genes of Carthamus tinctorius and construction plant expression vector].

    PubMed

    Yang, Wen-ting; Liu, Xiu-ming; Wan, Qiu; Yao, Na; Wang, Nan; Zhang, Xue-meng; Jiao, Zhong-da; Li, Hai-yan; Li, Xiao-kun

    2015-02-01

    Flavonol synthase (FLS) is one of the key enzymes in flavonoids metabolic pathways. In this study, middle sequence was obtained from Carthamus tinctorius transcriptome sequencing results. Full-length cDNAs of FLS was cloned from petals of C. tinctorius to FLS by using RT-PCR and RACE technology. Its full-length cDNA was 1,201 bp, with an open reading frame of 1,101 bp and 336 encoded amino acids. The phylogenetic analysis showed that, FLS gene encoded amino acids in C. tinctorius were highly homologous with amino acids in congeneric Compositae species, especially Rudbeckia laciniata. The pBASTA-FLS plant expression vector was successfully built by the molecular biology method, which lays a foundation for further studying biology functions of the gene and biosynthesis mechanism of flavonoids.

  2. Effects of temperature and photoperiod on sensory quality and contents of glucosinolates, flavonols and vitamin C in broccoli florets.

    PubMed

    Mølmann, Jørgen A B; Steindal, Anne L H; Bengtsson, Gunnar B; Seljåsen, Randi; Lea, Per; Skaret, Josefine; Johansen, Tor J

    2015-04-01

    Broccoli is grown around the world at a wide range of photoperiods and temperatures, which may influence both sensory quality and phytochemical contents. Florets produced in phytotron and at two semi-field sites (70 °N and 58 °N) were examined for effects of contrasting temperatures and photoperiods on sensory quality and contents of glucosinolates, flavonols and vitamin C. Growth conditions associated with high northern latitudes of low temperature and long photoperiods, produced bigger floral buds, and florets with sweeter taste and less colour hue than more southern conditions. The contents of vitamin C did not vary, while the response of individual glucosinolates varied with temperature and day length, and contents of quercetin and kaempferol were lower in phytotron than under semi-field conditions. Thus, our results show that contrasting temperatures and photoperiods influence the sensory quality of broccoli florets, while contents of different bioactive phytochemicals are not influenced in a unidirectional pattern.

  3. ZrCl4-mediated regio- and chemoselective Friedel-Crafts acylation of indole.

    PubMed

    Guchhait, Sankar K; Kashyap, Maneesh; Kamble, Harshad

    2011-06-03

    An efficient method for regio- and chemoselective Friedel-Crafts acylation of indole using acyl chlorides in the presence of ZrCl(4) has been discovered. It minimizes/eliminates common competing reactions that occur due to high and multiatom-nucleophilic character of indole. In this method, a wide range of aroyl, heteroaroyl alkenoyl, and alkanoyl chlorides undergo smooth acylation with various indoles without NH protection and afford 3-acylindoles in good to high yields.

  4. Steroidal glycosides with antiproliferative activities from Digitalis trojana.

    PubMed

    Kirmizibekmez, Hasan; Masullo, Milena; Festa, Michela; Capasso, Anna; Piacente, Sonia

    2014-04-01

    The phytochemical investigation of Digitalis trojana led to the isolation of two cardiac glycosides (1, 2), one pregnane glycoside (3), three furostanol type saponins (4-6), along with three cleroindicins (7-9), four phenylethanoid glycosides (10-13), two flavonoids (14, 15) and two phenolic acid derivatives (16, 17). The structure elucidation of the isolates was carried out by NMR experiments as well as ESI-MS. The cytotoxic activity of compounds 1-13 against a small panel of cancer cell lines, namely MCF-7, T98G, HT-29, PC-3, A375 and SH-SY5Y, was investigated. Compounds 1-6 showed antiproliferative activity against human breast MCF-7 and colon HT-29 cancer cell lines with IC50 values ranging from 8.3 to 50 μM. In order to understand the mechanism involved in the cell death, the active compounds were tested as pro-apoptotic agents using propidium iodide staining by flow cytometry method. No significant increase was observed in the apoptosis of the MCF-7 and HT-29 cancer cells. Moreover, the effects of the active compounds on cell proliferation were assessed on the same cancer cell lines by cell cycle analysis of DNA content using flow cytometry. No significative changes were observed in the cell cycle of MCF-7, while significant changes in G2 /M cell cycle phase of HT-29 cells were observed after treatment with digitalin (1), cariensoside (3) and 22-O-methylparvispinoside B (6) at 10 μM.

  5. Active Site and Laminarin Binding in Glycoside Hydrolase Family 55*

    PubMed Central

    Bianchetti, Christopher M.; Takasuka, Taichi E.; Deutsch, Sam; Udell, Hannah S.; Yik, Eric J.; Bergeman, Lai F.; Fox, Brian G.

    2015-01-01

    The Carbohydrate Active Enzyme (CAZy) database indicates that glycoside hydrolase family 55 (GH55) contains both endo- and exo-β-1,3-glucanases. The founding structure in the GH55 is PcLam55A from the white rot fungus Phanerochaete chrysosporium (Ishida, T., Fushinobu, S., Kawai, R., Kitaoka, M., Igarashi, K., and Samejima, M. (2009) Crystal structure of glycoside hydrolase family 55 β-1,3-glucanase from the basidiomycete Phanerochaete chrysosporium. J. Biol. Chem. 284, 10100–10109). Here, we present high resolution crystal structures of bacterial SacteLam55A from the highly cellulolytic Streptomyces sp. SirexAA-E with bound substrates and product. These structures, along with mutagenesis and kinetic studies, implicate Glu-502 as the catalytic acid (as proposed earlier for Glu-663 in PcLam55A) and a proton relay network of four residues in activating water as the nucleophile. Further, a set of conserved aromatic residues that define the active site apparently enforce an exo-glucanase reactivity as demonstrated by exhaustive hydrolysis reactions with purified laminarioligosaccharides. Two additional aromatic residues that line the substrate-binding channel show substrate-dependent conformational flexibility that may promote processive reactivity of the bound oligosaccharide in the bacterial enzymes. Gene synthesis carried out on ∼30% of the GH55 family gave 34 active enzymes (19% functional coverage of the nonredundant members of GH55). These active enzymes reacted with only laminarin from a panel of 10 different soluble and insoluble polysaccharides and displayed a broad range of specific activities and optima for pH and temperature. Application of this experimental method provides a new, systematic way to annotate glycoside hydrolase phylogenetic space for functional properties. PMID:25752603

  6. C21 steroidal glycosides from the roots of Cynanchum saccatum.

    PubMed

    Zhang, Mi; Rao, Li-Li; Xiang, Cheng; Li, Bao-Cai; Li, Peng

    2015-09-01

    Eight new C21 steroidal glycosides, named cynsaccatols A-H (1-8), along with two known analogs (9-10), were isolated from the roots of Cynanchum saccatum. Their structures were determined on the basis of detailed spectroscopic analysis, as well as HRESIMS. All compounds (1-10) were tested for their cytotoxicity in vitro using three human cancer cell lines (HepG2, Hela and U251), and compounds 1, 4, 5, 9, 10 showed weak inhibitory activities against different cell lines, respectively.

  7. 7-O-Methylated anthocyanidin glycosides from Catharanthus roseus.

    PubMed

    Toki, Kenjiro; Saito, Norio; Irie, Yuki; Tatsuzawa, Fumi; Shigihara, Atsushi; Honda, Toshio

    2008-03-01

    Anthocyanins were isolated from orange-red flowers of Catharanthus roseus cv 'Equator Deep Apricot', and identified as rosinidin 3-O-[6-O-(alpha-rhamnopyranosyl)-beta-galactopyranoside] (1), and also 7-O-methylcyanidin 3-O-[6-O-(alpha-rhamnopyranosyl)-beta-galactopyranoside] (2) by chemical and spectroscopic methods. Pigment 1 was found to be a major anthocyanin in the flowers of this cultivar. By contrast, the distribution of rosinidin glycosides is very limited in plants, and reported only in the flowers of Primula. Pigment 2 was found in smaller concentrations, but its aglycone, 7-O-methylcyanidin, has been reported only once before, from the fruit of mango.

  8. Flavonoid glycosides in bergamot juice (Citrus bergamia Risso).

    PubMed

    Gattuso, Giuseppe; Caristi, Corrado; Gargiulli, Claudia; Bellocco, Ersilia; Toscano, Giovanni; Leuzzi, Ugo

    2006-05-31

    A comprehensive profile of flavonoids in bergamot juice was obtained by a single DAD-ESI-LC-MS-MS course. Eight flavonoids were found for the first time, five of these are C-glucosides (lucenin-2, stellarin-2, isovitexin, scoparin, and orientin 4'-methyl ether), and three are O-glycosides (rhoifolin 4'-O-glucoside, chrysoeriol 7-O-neohesperidoside-4'-O-glucoside, and chrysoeriol 7-O-neohesperidoside). A method is proposed to differentiate chrysoeriol and diosmetin derivatives, which are often indistinguishable by LC-MS-MS. In-depth knowledge of the flavonoid content is the starting point for bergamot juice exploitation in food industry applications.

  9. New isoflavone glycosides from the stems of Dalbergia vietnamensis.

    PubMed

    Loan, Pham Thanh; Le Anh, Hoang Tuan; Cuc, Nguyen Thi; Yen, Duong Thi Hai; Hang, Dan Thi Thuy; Ha, Tran Minh; Nhiem, Nguyen Xuan; Van Du, Nguyen; Thai, Tran Huy; Van Minh, Chau; Van Kiem, Phan

    2014-06-01

    Two new isoflavone glycosides, dalspinosin 7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (1) and caviunin 7-O-(5-O-trans-p-coumaroyl)-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (2), and two known compounds, caviunin 7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (3) and caviunin (4) were isolated from the stems of Dalbergia vietnamensis. Their structures were determined by the combination of spectroscopic and chemical methods, including 1D- and 2D-NMR spectroscopy, as well as by comparing with the NMR data reported in the literature.

  10. A new benzophenone glycoside from the leaves of Mitracarpus villosus.

    PubMed

    Ngwoke, Kenneth G; Orame, Njideka; Liu, Shuai; Okoye, Festus B C; Daletos, Georgios; Proksch, Peter

    2017-03-22

    A new benzophenone glycoside, mitraphenone A (1), together with three known compounds (2-4) were isolated from the leaves of the traditionally used medicinal plant Mitracarpus villosus (Rubiaceae) collected in Nigeria. A combination of one- and two-dimensional NMR spectroscopic and mass spectrometric measurements were carried out to identify the structure of 1. All isolated compounds (1-4) were screened for their antibacterial activity against several Gram-positive and Gram-negative bacteria. Compound 1 exhibited moderate activity against Enterococcus faecium (strains ATCC 35667 and ATCC 700221) and Staphylococcus aureus ATCC 25923 with MIC values ranging from 25 to 50 μM.

  11. [Iridoid glycosides from buds of Jasminum officinale L. var. grandiflorum].

    PubMed

    Zhao, Gui-qin; Yin, Zhi-feng; Liu, Yu-cui; Li, Hong-bo

    2011-10-01

    The study on the buds of Jasminum officinale L. var. grandiflorum was carried out to look for anti-HBV constituents. The isolation and purification were performed by HPLC and chromatography on silica gel, polyamide and Sephadex LH-20 column. The structures were elucidated on the basis of physicochemical properties and spectral analysis. Six iridoid glycosides were identified as jasgranoside B (1), 6-O-methy-catalpol (2), deacetyl asperulosidic acid (3), aucubin (4), 8-dehydroxy shanzhiside (5), and loganin (6). Jasgranoside B (1) is a new compound. Compounds 2-6 were isolated from Jasminum officinale L. var. grandiflorum for the first time.

  12. New cyclopeptide alkaloid and lignan glycoside from Justicia procumbens.

    PubMed

    Jin, Hong; Chen, Li; Tian, Ying; Li, Bin; Dong, Jun-Xing

    2015-01-01

    This study reported a new cyclopeptide alkaloid, justicianene A (1), and a new lignan glycoside, procumbenoside H (2), isolated from Justicia procumbens. The structures of the new compounds were elucidated by means of spectroscopic analysis, including extensive 2D NMR studies and mass spectrometry. Cyclopeptide alkaloids were first observed from the genus Justicia. Compound 2 was cytotoxic against human LoVo colon carcinoma cells with an IC50 value of 17.908 ± 1.949 μM.

  13. Three New Cytotoxic Polyhydroxysteroidal Glycosides from Starfish Craspidaster hesperus

    PubMed Central

    Kang, Jun-Xia; Kang, Yong-Feng; Han, Hua

    2016-01-01

    Three new polyhydroxysteroidal glycosides, hesperuside A (1), B (2), and C (3), as well as a known novaeguinoside A (4), were isolated from the ethanol extract of starfish Craspidaster hesperus collected from the South China Sea. Their structures were elucidated by extensive spectroscopic methods and chemical evidence. The compounds 1–3 present unprecedented carbohydrate chain 3-O-methyl-β-d-galactopyranose, which differ from each other in the side chains. These compounds exhibited cytotoxicity against human tumor cells BEL-7402, MOLT-4, and A-549 in vitro. PMID:27775561

  14. Additional new minor cucurbitane glycosides from Siraitia grosvenorii.

    PubMed

    Prakash, Indra; Chaturvedula, Venkata Sai Prakash

    2014-03-24

    Continuous phytochemical studies of the crude extract of Luo Han Guo (Siraitia grosvenorii) furnished three additional new cucurbitane triterpene glycosides, namely 11-deoxymogroside V, 11-deoxyisomogroside V, and 11-deoxymogroside VI. The structures of all the isolated compounds were characterized on the basis of extensive NMR and mass spectral data as well as hydrolysis studies. The complete ¹H- and ¹³C-NMR spectral assignments of the three unknown compounds are reported for the first time based on COSY, TOCSY, HSQC, and HMBC spectroscopic data.

  15. A new pregnane glycoside from Gomphocarpus fruticosus growing in Egypt.

    PubMed

    Marzouk, Amani M; Osman, Samir M; Gohar, Ahmed A

    2016-01-01

    Phytochemical investigation of Gomphocarpus fruticosus (L.) Ait. of Egyptian origin afforded the new pregnane glycoside lineolon-3-O-[β-D-oleandropyranosyl-(1-4)-β-D-cymaropyranosyl-(1-4)-β-D-cymaropyranoside], along with six known compounds. The structures of the isolated compounds were elucidated on the basis of extensive spectroscopic evidences derived from 1D, 2D NMR experiments, mass spectrometry and by comparing their physical and spectroscopic data to literature. These included the triterpenoids 3β-taraxerol, 3β-taraxerol acetate and betulinic acid, which are identified for the first time in G. fruticosus and the cardenolides uzarigenin, gomphoside and calotropin.

  16. New pregnane glycoside derivative from Caralluma retrospiciens (Ehrenb).

    PubMed

    Elsebai, Mahmoud Fahmi; Mohamed, Ietidal El-Tahir

    2015-01-01

    Retrospinoside (1) is a new polyoxy pregnane glycoside which was isolated and characterised from the aerial parts of Caralluma retrospiciens (Ehrenb.) N. E. Br., family Apocynaceae. The structure was established as 3-O-[β-D-glucopyranosyl-(1 → 4)-β-D-(3-O-methyl-6-desoxygalactopyranosy)]-14,15,20-trihydroxy-4β-pregnane. Its structural elucidation was performed through extensive spectroscopic measurements including 1D- and 2D-NMR, and HRMS, in addition to chemical methods.

  17. Phenylpropanoid Glycosides from the Leaves of Ananas comosus.

    PubMed

    Chen, Wen-Hao; Huang, Xiao-Juan; Shu, Huo-Ming; Hui, Yang; Guo, Fei-Yan; Song, Xiao-Ping; Ji, Ming-Hui; Chen, Guang-Ying

    2015-12-01

    Two new phenylpropanoid glycosides, named β-D-(1-O-acetyl-3,6-O-diferuloyl) fructofuranosyl β-D-6'-O-acetylglucopyranoside (1) and β-D-(1-O-acetyl-3,6-O-diferuloyl) fructofuranosyl α-D-glucopyranoside (2), along with two known analogues (3-4) and four glycerides (5-8), were isolated from the EtOAc extract of the leaves of Ananas comosus. Their structures were elucidated on the basis of 1D- and 2D-NMR analyses, as well as HR-ESI-MS experiments. Compounds 1-4 showed significant antibacterial activities against Staphylococcus aureus and Escherichia coli.

  18. Acute ethanol treatment induces a bimodal response of phospholipid acylation rates in rat red blood cells

    SciTech Connect

    Verine, A.; Valette, A.; Richard, D.; Boyer, J. )

    1991-01-01

    A single intraperitoneal injection of ethanol in rats elicited a bimodal response of acylation rates in phosphatidylcholine and phosphatidylethanolamine of intact red blood cells. Within an initial period, ethanol inhibited acylation rates. The inhibition then reversed, leading to increased values which persisted as long as ethanol was present in plasma. Acylation rates were not correlated to ethanol concentrations in plasma. The authors suggest that red cells first desensitize to, then overcompensate for the inhibitory effect of ethanol on acylation reactions. These adaptive changes may be one of the events mediating membrane tolerance to ethanol.

  19. A novel plasmid for detection of N-acyl homoserine lactones.

    PubMed

    Ling, Elizabeth A; Ellison, Matthew L; Pesci, Everett C

    2009-07-01

    Many bacteria utilize acyl-homoserine lactones as cell to cell signals that can regulate the expression of numerous genes. Structural differences in acyl-homoserine lactones produced by different bacteria, such as acyl side chain length and the presence or absence of an oxy group, make many of the commonly used detection bioassays impractical for broad range detection. Here we present a simple, broad range acyl-homoserine lactone detection bioassay that can be used to detect a wide range of these chemical signals. A plasmid (pEAL01) was constructed and transformed into Pseudomonas aeruginosa strain QSC105 to allow for detection of a broad range of acyl-homoserine lactones through induction of a lasB'-lacZ transcriptional fusion. Monitoring beta-galactosidase activity from this bioassay showed that P. aeruginosa strain QSC105 (pEAL01) could detect the presence of eight acyl-homoserine lactones tested at physiological concentrations. This novel strain could also detect acyl-homoserine lactones from the extracts of four different bacteria that produce different acyl-homoserine lactones signals. These data indicate that strain QSC105 (pEAL01) can be used to detect a wide variety of acyl-homoserine lactones by a simple beta-galactosidase assay and this bioassay could be a useful and inexpensive tool to quickly identify the presence of these signal molecules.

  20. New Knowledge About Old Drugs: The Anti-Inflammatory Properties of Cardiac Glycosides.

    PubMed

    Fürst, Robert; Zündorf, Ilse; Dingermann, Theo

    2017-03-15

    In the 19th century, cardio-active steroid glycosides, shortly cardiac glycosides, were scientifically established as drugs against heart failure. Their in vivo, cellular, and molecular actions as well as their predominant target, Na(+)-K(+)-ATPase, have been comprehensively investigated in the 20th century and the discovery of endogenous cardiac glycosides has fostered this research field. In the last years, however, results from clinical trials and meta-analyses have questioned their therapeutic value due to efficacy and safety issues. This has led to a considerable decline of their usage. Beyond the cardiovascular system, cardiac glycosides have been increasingly recognized as antitumor compounds and Na(+)-K(+)-ATPase has evolved into a promising drug target in oncology. A wealth of review articles exists that intensively discuss these topics. Surprisingly, the anti-inflammatory actions of cardiac glycosides, which were discovered in the 1960s, have so far hardly been perceived and have not yet been summarized. This review provides an overview of the in vivo and in vitro actions of cardiac glycosides on inflammatory processes and of the signaling mechanisms responsible for these effects: cardiac glycosides have been found to decrease inflammatory symptoms in different animal models of acute and chronic inflammation. Regarding the underlying mechanisms most research has focused on leukocytes. In these cells, cardiac glycosides primarily inhibit cell proliferation and the secretion of proinflammatory cytokines.

  1. Dalvelutinoside, a new isoflavone glycoside from the methanol extract of Dalbergia velutina roots.

    PubMed

    Kaennakam, Sutin; Siripong, Pongpun; Tip-Pyang, Santi

    2016-07-01

    A new isoflavone glycoside, dalvelutinoside (1), together with one known isoflavone (2) and five known isoflavone glycosides (3-7) were isolated from the methanol extract of the roots of Dalbergia velutina. Their structures were determined by spectroscopic analysis. All isolated compounds were evaluated for their cytotoxicity against KB and HeLa cell lines.

  2. Two new nor-triterpene glycosides from peruvian "Uña de Gato" (Uncaria tomentosa).

    PubMed

    Kitajima, Mariko; Hashimoto, Ken-Ichiro; Yokoya, Masashi; Takayama, Hiromitsu; Sandoval, Manuel; Aimi, Norio

    2003-02-01

    Two new 27-nor-triterpene glycosides, tomentosides A (1) and B (2), were isolated from Peruvian "Uña de Gato" (cat's claw, plant of origin: Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analysis and chemical interconversions. This is the first report of naturally occurring pyroquinovic acid glycosides.

  3. A new cembrane glycoside in Asterothamnus centrali-asiaticus from Gobi Desert.

    PubMed

    Todorova, Milka; Trendafilova, Antoaneta; Javsmaa, Namshir; Altantsetseg, Shatarin; Shatar, Sanduin

    2013-09-01

    A new cembrane glycoside, nephthenol 15-O-β-d-quinovoside, was isolated from the aerial parts of Asterothamnus centrali-asiaticus. Its structure was elucidated by 1D and 2D NMR spectroscopic analysis, as well as by mass spectrometry. This is the first report of the occurrence of a cembrane glycoside in vascular plants.

  4. Annotation and comparative analysis of the glycoside hydrolase genes in Brachypodium distachyon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glycoside hydrolase genes have been previously cataloged for Oryza sativa (rice), the model dicotyledonous plant Arabidopsis thaliana, and the fast-growing tree Populus trichocarpa (poplar). To improve our understanding of glycoside hydrolases in plants generally and in grasses specifically, we ann...

  5. Synthesis of cardiac glycoside analogs by catalyst-controlled, regioselective glycosylation of digitoxin.

    PubMed

    Beale, Thomas M; Taylor, Mark S

    2013-03-15

    The cardiac glycoside natural product digitoxin was selectively glycosylated at one of its five hydroxyl groups using a borinic acid derived catalyst. This method provided access to the glycosylation pattern characteristic of a subclass of natural products from Digitalis purpurea. Variation of the glycosyl donor was tolerated, enabling the synthesis of novel cardiac glycoside analogs from readily available materials.

  6. 2-C-branched glycosides from 2'-carbonylalkyl 2-O-Ms(Ts)-C-glycosides. A tandem SN2-SN2 reaction via 1,2-cyclopropanated sugars.

    PubMed

    Shao, Huawu; Ekthawatchai, Sanchai; Wu, Shih-Hsiung; Zou, Wei

    2004-09-30

    [reaction: see text] Under basic conditions, 2'-aldehydo (acetonyl) 2-O-Ms(Ts)-alpha-C-glycosides undergo an intramolecular S(N)2 reaction to form 1,2-cyclopropanated sugars, which react with nucleophiles (alcohols, thiols, and azide) at the anomeric carbon to give 2-C-branched glycosides. By way of contrast, the 1,2-cyclopropanes derived from 2'-ketones only react with thiols to give 2-C-branched thioglycosides.

  7. Mass spectrometric imaging of flavonoid glycosides and biflavonoids in Ginkgo biloba L.

    PubMed

    Beck, Sebastian; Stengel, Julia

    2016-10-01

    Ginkgo biloba L. is known to be rich in flavonoids and flavonoid glycosides. However, the distribution within specific plant organs (e.g. within leaves) is not known. By using HPLC-MS and MS/MS we have identified a number of previously known G. biloba flavonoid glycosides and biflavonoids from leaves. Namely, kaempferol, quercetin, isorhamnetin, myricetin, laricitrin/mearnsetin and apigenin glycosides were identified. Furthermore, biflavonoids like ginkgetin/isoginkgetin were also detected. The application of MALDI mass spectrometric imaging, enabled the compilation of concentration profiles of flavonoid glycosides and biflavonoids in G. biloba L. leaves. Both, flavonoid glycosides and biflavonoids show a distinct distribution in leaf thin sections of G. biloba L.

  8. Merremins A-G, resin glycosides from Merremia hederacea with multidrug resistance reversal activity.

    PubMed

    Wang, Wen-qiong; Song, Wei-bin; Lan, Xiao-jing; Huang, Min; Xuan, Li-jiang

    2014-10-24

    Five new pentasaccharide resin glycosides, named merremins A-E (1-5), two new pentasaccharide resin glycoside methyl esters, named merremins F and G (6, 7), and four known resin glycosides, murucoidin IV, murucoidin V, stoloniferin IV, and murucoidin XVII, were obtained from the aerial parts of Merremia hederacea. This is the first report of resin glycosides obtained from M. hederacea. In addition, the new compounds can be divided into three types: those possessing an 18-membered ring (1-4), compound 5 with a 20-membered ring, and those with an acyclic core (6, 7). Furthermore, the different types of resin glycosides were evaluated for their multidrug resistance reversal activities. Compounds 1, 5, 6, and murucoidin V were noncytotoxic and enhanced the cytotoxicity of vinblastine by 2.3-142.5-fold at 25 μM. Compound 5 and murucoidin V, with 20-membered rings, were more active than compound 1, with an 18-membered ring.

  9. Synthesis of gold nanoparticles with glycosides: synthetic trends based on the structures of glycones and aglycones.

    PubMed

    Jung, Jisung; Park, Suryeon; Hong, Suckchang; Ha, Min Woo; Park, Hyeung-geun; Park, Youmie; Lee, Hyo-Jong; Park, Yohan

    2014-03-11

    A new, room temperature synthetic method for gold nanoparticles from auric acid with glycosides as reducing agents in aqueous NaOH is presented. As a mechanistic study of the oxidation sites on the glycosides, eight sugar-containing reductants (glycoside, glucose, glucuronic acid) have been tested in the synthesis of gold nanoparticles to determine their trends based on the structures of glycones and aglycones. As a result of the comparison among the eight sugar-containing reductants, it was determined that C-6 of glycosides is oxidized to a carboxylic acid during the reduction of auric acid. To detect the oxidized compounds of the glycosides, the reaction mixtures were monitored by (13)C NMR. Among the eight sugar-containing reductants, phenyl β-D-glucoside generated the highest synthetic yield of mono-dispersed, round gold nanoparticles (13.15±1.30 nm, 99.7% yield).

  10. Hydration of vinyl ether groups by unsaturated glycoside hydrolases and their role in bacterial pathogenesis.

    PubMed

    Hashimoto, Wataru; Itoh, Takafumi; Maruyama, Yukie; Mikami, Bunzo; Murata, Kousaku

    2007-12-01

    Many pathogenic microorganisms invade mammalian and/or plant cells by producing polysaccharide-degrading enzymes (lyases and hydrolases). Mammalian glycosaminoglycans and plant pectins that form part of the cell surface matrix are typical targets for these microbial enzymes. Unsaturated glycoside hydrolase catalyzes the hydrolytic release of an unsaturated uronic acid from oligosaccharides, which are produced through the reaction of matrix-degrading polysaccharide lyase. This enzymatic ability suggests that unsaturated glycoside hydrolases function as virulence factors in microbial infection. This review focuses on the molecular identification, bacterial distribution, and structure/function relationships of these enzymes. In contrast to general glycoside hydrolases, in which the catalytic mechanism involves the retention or inversion of an anomeric configuration, unsaturated glycoside hydrolases uniquely trigger the hydrolysis of vinyl ether groups in unsaturated saccharides but not of their glycosidic bonds.

  11. Stimulation of steviol glycoside accumulation in Stevia rebaudiana by red LED light.

    PubMed

    Ceunen, Stijn; Werbrouck, Stefaan; Geuns, Jan M C

    2012-05-01

    The aim of this study was to determine whether steviol glycoside accumulation is under phytochrome control. The results indicate that Stevia rebaudiana Bertoni plants grown under short-day conditions showed precocious flowering and stagnation of steviol glycoside accumulation. Long night interruption by red LED light stimulated and sustained the vegetative growth as well as the accumulation of steviol glycosides in the leaves. After 7 weeks of treatment, steviol glycoside content was about two-fold higher in LED-treated plants than in the short-day control group. The effects of red LED light were measured both in a greenhouse and in a phytotron, irrespective of cultivar-specific differences. Therefore, it can be concluded that a mid-night interruption by red LED light during short photoperiods provides an easy and inexpensive method to increase vegetative leaf biomass production with an increased steviol glycoside yield.

  12. Quantitation of sweet steviol glycosides by means of a HILIC-MS/MS-SIDA approach.

    PubMed

    Well, Caroline; Frank, Oliver; Hofmann, Thomas

    2013-11-27

    Meeting the rising consumer demand for natural food ingredients, steviol glycosides, the sweet principle of Stevia rebaudiana Bertoni (Bertoni), have recently been approved as food additives in the European Union. As regulatory constraints require sensitive methods to analyze the sweet-tasting steviol glycosides in foods and beverages, a HILIC-MS/MS method was developed enabling the accurate and reliable quantitation of the major steviol glycosides stevioside, rebaudiosides A-F, steviolbioside, rubusoside, and dulcoside A by using the corresponding deuterated 16,17-dihydrosteviol glycosides as suitable internal standards. This quantitation not only enables the analysis of the individual steviol glycosides in foods and beverages but also can support the optimization of breeding and postharvest downstream processing of Stevia plants to produce preferentially sweet and least bitter tasting Stevia extracts.

  13. Anti-HIV diphyllin glycosides from Justicia gendarussa.

    PubMed

    Zhang, Hong-Jie; Rumschlag-Booms, Emily; Guan, Yi-Fu; Liu, Kang-Lun; Wang, Dong-Ying; Li, Wan-Fei; Nguyen, Van Hung; Cuong, Nguyen Manh; Soejarto, Djaja Doel; Fong, Harry H S; Rong, Lijun

    2017-04-01

    In a search for new anti-HIV active leads from over several thousands of plant extracts, we have identified a potent plant lead. The active plant is determined as Justicia gendarussa (Acanthaceae), a medicinal plant that has been used for the treatment of injury, arthritis and rheumatism in Asia including China. Our bioassay-guided fractionation of the methanol extract of the stems and barks of the plant led to the isolation of two anti-HIV compounds, justiprocumins A and B. The compounds are identified as new arylnaphthalide lignans (ANL) glycosides. We further determined that the ANL glycosides are the chemical constituents that contribute to the anti-HIV activity of this plant. Justiprocumin B displayed potent activity against a broad spectrum of HIV strains with IC50 values in the range of 15-21 nM (AZT, IC50 77-95 nM). The compound also displayed potent inhibitory activity against the NRTI (nucleoside reverse transcriptase inhibitor)-resistant isolate (HIV-11617-1) of the analogue (AZT) as well as the NNRTI (non-nucleoside reverse transcriptase inhibitor)-resistant isolate (HIV-1N119) of the analogue (nevaripine).

  14. Glycosides from edible sea cucumbers stimulate macrophages via purinergic receptors

    PubMed Central

    Aminin, Dmitry; Pislyagin, Evgeny; Astashev, Maxim; Es’kov, Andrey; Kozhemyako, Valery; Avilov, Sergei; Zelepuga, Elena; Yurchenko, Ekaterina; Kaluzhskiy, Leonid; Kozlovskaya, Emma; Ivanov, Alexis; Stonik, Valentin

    2016-01-01

    Since ancient times, edible sea cucumbers have been considered a jewel of the seabed and used in Asian folk medicine for stimulation of resistance against different diseases. However, the power of this sea food has not been established on a molecular level. A particular group of triterpene glycosides was found to be characteristic metabolites of the animals, responsible for this biological action. Using one of them, cucumarioside A2-2 (CA2-2) from the edible Cucumaria japonica species as an example as well as inhibitory analysis, patch-clamp on single macrophages, small interfering RNA technique, immunoblotting, SPR analysis, computer modeling and other methods, we demonstrate low doses of CA2-2 specifically to interact with P2X receptors (predominantly P2X4) on membranes of mature macrophages, enhancing the reversible ATP-dependent Ca2+ intake and recovering Ca2+ transport at inactivation of these receptors. As result, interaction of glycosides of this type with P2X receptors leads to activation of cellular immunity. PMID:28004778

  15. Allosteric indicator displacement enzyme assay for a cyanogenic glycoside.

    PubMed

    Jose, D Amilan; Elstner, Martin; Schiller, Alexander

    2013-10-18

    Indicator displacement assays (IDAs) represent an elegant approach in supramolecular analytical chemistry. Herein, we report a chemical biosensor for the selective detection of the cyanogenic glycoside amygdalin in aqueous solution. The hybrid sensor consists of the enzyme β-glucosidase and a boronic acid appended viologen together with a fluorescent reporter dye. β-Glucosidase degrades the cyanogenic glycoside amygdalin into hydrogen cyanide, glucose, and benzaldehyde. Only the released cyanide binds at the allosteric site of the receptor (boronic acid) thereby inducing changes in the affinity of a formerly bound fluorescent indicator dye at the other side of the receptor. Thus, the sensing probe performs as allosteric indicator displacement assay (AIDA) for cyanide in water. Interference studies with inorganic anions and glucose revealed that cyanide is solely responsible for the change in the fluorescent signal. DFT calculations on a model compound revealed a 1:1 binding ratio of the boronic acid and cyanide ion. The fluorescent enzyme assay for β-glucosidase uses amygdalin as natural substrate and allows measuring Michaelis-Menten kinetics in microtiter plates. The allosteric indicator displacement assay (AIDA) probe can also be used to detect cyanide traces in commercial amygdalin samples.

  16. New Glycosides and Trypanocidal Metabolites from Vangueria edulis

    PubMed Central

    Mohamed, Shaymaa M. M.; Elokely, Khaled M.; Bachkeet, Enaam Y.; Bayoumi, Soad A. L.; Carnevale, Vincenzo; Klein, Michael L.; Cutler, Stephen J.

    2016-01-01

    A new iridoid glucoside, 10-methoxy apodanthoside (1), and a new monoterpene glycoside, (3S,6S)-cis linalool-3,7-oxide O-β-D-glucopyranosyl-(1″→5′)-β-D-xylofuranoside (2), were isolated from V. edulis (Rubiaceae), along with eighteen known compounds (3–20), including monoterpenes, iridoid glycosides, and a lignin, which were encountered for the first time in the genus Vangueria,. The structural elucidation of the isolates was based on the analysis of spectroscopic (1D and 2D NMR) and HR-ESI-MS data. Detailed stereochemical studies of 1 and related iridoid glucosides (compounds 3, 4 and 8) were made by matching the calculated ECD peaks with the experimental ones. All isolates were tested for their antiprotozoal, antifungal, and antiplasmodial activities. Compounds 9, 15 and 16 showed good trypanocidal activities against Trypanosoma brucei brucei with IC50 values of 8.18, 9.02 and 7.80 μg/mL, respectively and IC90 values of >10, >10 and 9.76 μg/mL, respectively. Compound 16 showed a moderate activity against Candida glabrata with an IC50 value of 8.66 μg/mL. Compound 20 showed a weak antiplasmodial activity against chloroquine-sensitive (D6) and resistant (W2) Plasmodium falciparum with IC50 values of 3.29 (SI, >1.4) and 4.53 (SI, >1) μg/mL, respectively. PMID:26749819

  17. Recovering glycoside hydrolase genes from active tundra cellulolytic bacteria.

    PubMed

    Pinnell, Lee J; Dunford, Eric; Ronan, Patrick; Hausner, Martina; Neufeld, Josh D

    2014-07-01

    Bacteria responsible for cellulose hydrolysis in situ are poorly understood, largely because of the relatively recent development of cultivation-independent methods for their detection and characterization. This study combined DNA stable-isotope probing (DNA-SIP) and metagenomics for identifying active bacterial communities that assimilated carbon from glucose and cellulose in Arctic tundra microcosms. Following DNA-SIP, bacterial fingerprint analysis of gradient fractions confirmed isotopic enrichment. Sequenced fingerprint bands and clone library analysis of 16S rRNA genes identified active bacterial taxa associated with cellulose-associated labelled DNA, including Bacteroidetes (Sphingobacteriales), Betaproteobacteria (Burkholderiales), Alphaproteobacteria (Caulobacteraceae), and Chloroflexi (Anaerolineaceae). We also compared glycoside hydrolase metagenomic profiles from bulk soil and heavy DNA recovered from DNA-SIP incubations. Active populations consuming [(13)C]glucose and [(13)C]cellulose were distinct, based on ordinations of light and heavy DNA. Metagenomic analysis demonstrated a ∼3-fold increase in the relative abundance of glycoside hydrolases in DNA-SIP libraries over bulk-soil libraries. The data also indicate that multiple displacement amplification introduced bias into the resulting metagenomic analysis. This research identified DNA-SIP incubation conditions for glucose and cellulose that were suitable for Arctic tundra soil and confirmed that DNA-SIP enrichment can increase target gene frequencies in metagenomic libraries.

  18. Steviol glycosides modulate glucose transport in different cell types.

    PubMed

    Rizzo, Benedetta; Zambonin, Laura; Angeloni, Cristina; Leoncini, Emanuela; Dalla Sega, Francesco Vieceli; Prata, Cecilia; Fiorentini, Diana; Hrelia, Silvana

    2013-01-01

    Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway.

  19. Steviol Glycosides Modulate Glucose Transport in Different Cell Types

    PubMed Central

    Rizzo, Benedetta; Zambonin, Laura; Leoncini, Emanuela; Vieceli Dalla Sega, Francesco; Prata, Cecilia; Fiorentini, Diana; Hrelia, Silvana

    2013-01-01

    Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway. PMID:24327825

  20. Flacourtosides A-F, phenolic glycosides isolated from Flacourtia ramontchi.

    PubMed

    Bourjot, Mélanie; Leyssen, Pieter; Eydoux, Cécilia; Guillemot, Jean-Claude; Canard, Bruno; Rasoanaivo, Philippe; Guéritte, Françoise; Litaudon, Marc

    2012-04-27

    In an effort to identify novel inhibitors of chikungunya (CHIKV) and dengue (DENV) virus replication, a systematic study with 820 ethyl acetate extracts of madagascan plants was performed in a virus-cell-based assay for CHIKV, and a DENV NS5 RNA-dependent RNA polymerase (RdRp) assay. The extract obtained from the stem bark of Flacourtia ramontchi was selected for its significant activity in both assays. Six new phenolic glycosides, named flacourtosides A-F (1-6), phenolic glycosides itoside H, xylosmin, scolochinenoside D, and poliothrysoside, and betulinic acid 3β-caffeate were obtained using the bioassay-guided isolation process. Their structures were elucidated by comprehensive analyses of NMR spectroscopic and mass spectrometric data. Even though several extracts and fractions showed significant selective antiviral activity in the CHIKV virus-cell-based assay, none of the purified compounds did. However, in the DENV RNA polymerase assay, significant inhibition was observed with betulinic acid 3β-caffeate (IC(50) = 0.85 ± 0.1 μM) and to a lesser extent for the flacourtosides A and E (1 and 5, respectively), and scolochinenoside D (IC(50) values ~10 μM).

  1. Identification and quantification of glucosinolate and flavonol compounds in rocket salad (Eruca sativa, Eruca vesicaria and Diplotaxis tenuifolia) by LC–MS: Highlighting the potential for improving nutritional value of rocket crops

    PubMed Central

    Bell, Luke; Oruna-Concha, Maria Jose; Wagstaff, Carol

    2015-01-01

    Liquid chromatography mass spectrometry (LC–MS) was used to obtain glucosinolate and flavonol content for 35 rocket accessions and commercial varieties. 13 glucosinolates and 11 flavonol compounds were identified. Semi-quantitative methods were used to estimate concentrations of both groups of compounds. Minor glucosinolate composition was found to be different between accessions; concentrations varied significantly. Flavonols showed differentiation between genera, with Diplotaxis accumulating quercetin glucosides and Eruca accumulating kaempferol glucosides. Several compounds were detected in each genus that have only previously been reported in the other. We highlight how knowledge of phytochemical content and concentration can be used to breed new, nutritionally superior varieties. We also demonstrate the effects of controlled environment conditions on the accumulations of glucosinolates and flavonols and explore the reasons for differences with previous studies. We stress the importance of consistent experimental design between research groups to effectively compare and contrast results. PMID:25442630

  2. Identification and quantification of glucosinolate and flavonol compounds in rocket salad (Eruca sativa, Eruca vesicaria and Diplotaxis tenuifolia) by LC-MS: highlighting the potential for improving nutritional value of rocket crops.

    PubMed

    Bell, Luke; Oruna-Concha, Maria Jose; Wagstaff, Carol

    2015-04-01

    Liquid chromatography mass spectrometry (LC-MS) was used to obtain glucosinolate and flavonol content for 35 rocket accessions and commercial varieties. 13 glucosinolates and 11 flavonol compounds were identified. Semi-quantitative methods were used to estimate concentrations of both groups of compounds. Minor glucosinolate composition was found to be different between accessions; concentrations varied significantly. Flavonols showed differentiation between genera, with Diplotaxis accumulating quercetin glucosides and Eruca accumulating kaempferol glucosides. Several compounds were detected in each genus that have only previously been reported in the other. We highlight how knowledge of phytochemical content and concentration can be used to breed new, nutritionally superior varieties. We also demonstrate the effects of controlled environment conditions on the accumulations of glucosinolates and flavonols and explore the reasons for differences with previous studies. We stress the importance of consistent experimental design between research groups to effectively compare and contrast results.

  3. Evaluation of the content variation of anthraquinone glycosides in rhubarb by UPLC-PDA

    PubMed Central

    2013-01-01

    Background Rhubarb is an important Chinese medicinal herb with a long history of over 2000 years and has been commonly used as a laxative. It is the radix and rhizome of Rheum officinale Baill., R. palmatum L. and R. tanguticum Maxim, all of which are mainly distributed in a broad region in the Tibetan plateau. Anthraquinone glycosides are a series of major active ingredients found in all three species. They are key intermediates in the anthraquinone secondary metabolism and the sennnoside biosynthesis. The variation of the anthraquinone glycoside content in rhubarb in response to specific factors remains an attractive topic. Results A simple and sensitive Ultra Performance Liquid Chromatography with Photo-Diode Array (UPLC-PDA) detector was developed for the simultaneous determination of six anthraquinone glycosides in rhubarb, i.e., aloeemodin-8-O-glucoside, rhein-8-O-glucoside, chrysophanol-1-O-glucoside, emodin-1-O-glucoside, chrysophanol-8-O-glucoside, emodin-8-O-glucoside. Twenty-seven batches from three species were submitted to the multi-component analysis. The results showed that the anthraquinone glycoside content varied significantly even within the same species. The results showed that the anthraquinone glycoside content varied significantly within the same species but not between different species. The PCA and content analysis results confirmed that the plant species has no obvious effect on the content variation. Neither was any significant correlation observed between the anthraquinone glycoside content and the geographic distribution of the rhubarb. Through correlational analysis, altitude was found to be the main factor that affects the anthraquinone glycoside content in rhubarb. Rhubarb grown at higher altitude has higher anthraquinone glycoside content. Conclusions This work provides a rapid, sensitive and accurate UPLC-PDA method for the simultaneous determination of six anthraquinone glycosides in rhubarb. The anthraquinone glycoside content

  4. Acylation of Antioxidant of Bamboo Leaves with Fatty Acids by Lipase and the Acylated Derivatives’ Efficiency in the Inhibition of Acrylamide Formation in Fried Potato Crisps

    PubMed Central

    Ma, Xiang; Wang, Erpei; Lu, Yuyun; Wang, Yong; Ou, Shiyi; Yan, Rian

    2015-01-01

    This study selectively acylated the primary hydroxyl groups on flavonoids in antioxidant of bamboo leaves (AOB) using lauric acid with Candida antarctica lipase B in tert-amyl-alcohol. The separation and isolation of acylated derivatives were performed using silica gel column chromatography with a mixture of dichloromethane/diethyl ether/methanol as eluents. Both thin layer chromatography and high-performance liquid chromatography analyses confirmed the high efficiency of the isolation process with the purified orientin-6″-laurate, isoorientin-6″-laurate, vitexin-6″-laurate, and isovitexin-6″-laurate that were obtained. The addition of AOB and acylated AOB reduced acrylamide formation in fried potato crisps. Results showed that 0.05% AOB and 0.05% and 0.1% acylated AOB groups significantly (p < 0.05) reduced the content of acrylamide in potato crisps by 30.7%, 44.5%, and 46.9%, respectively. PMID:26098744

  5. Acylation of Antioxidant of Bamboo Leaves with Fatty Acids by Lipase and the Acylated Derivatives' Efficiency in the Inhibition of Acrylamide Formation in Fried Potato Crisps.

    PubMed

    Ma, Xiang; Wang, Erpei; Lu, Yuyun; Wang, Yong; Ou, Shiyi; Yan, Rian

    2015-01-01

    This study selectively acylated the primary hydroxyl groups on flavonoids in antioxidant of bamboo leaves (AOB) using lauric acid with Candida antarctica lipase B in tert-amyl-alcohol. The separation and isolation of acylated derivatives were performed using silica gel column chromatography with a mixture of dichloromethane/diethyl ether/methanol as eluents. Both thin layer chromatography and high-performance liquid chromatography analyses confirmed the high efficiency of the isolation process with the purified orientin-6″-laurate, isoorientin-6″-laurate, vitexin-6″-laurate, and isovitexin-6″-laurate that were obtained. The addition of AOB and acylated AOB reduced acrylamide formation in fried potato crisps. Results showed that 0.05% AOB and 0.05% and 0.1% acylated AOB groups significantly (p < 0.05) reduced the content of acrylamide in potato crisps by 30.7%, 44.5%, and 46.9%, respectively.

  6. Acyl-CoA Synthetase Is Located in the Outer Membrane and Acyl-CoA Thioesterase in the Inner Membrane of Pea Chloroplast Envelopes 1

    PubMed Central

    Andrews, Jaen; Keegstra, Kenneth

    1983-01-01

    Both acyl-CoA synthetase and acyl-CoA thioesterase activities are present in chloroplast envelope membranes. The functions of these enzymes in lipid metabolism remains unresolved, although the synthetase has been proposed to be involved in either plastid galactolipid synthesis or the export of plastid-synthesized fatty acids to the cytoplasm. We have examined the locations of both enzymes within the two envelope membranes of pea (Pisum sativum var Laxton's Progress No. 9) chloroplasts. Inner and outer envelope membranes were purified from unfractionated envelope preparations by linear density sucrose gradient centrifugation. Acyl-CoA synthetase was located in the outer envelope membrane while acyl-CoA thioesterase was located in the inner envelope membrane. Thus, it seems unlikely that the synthetase is directly involved in galactolipid assembly. Instead, its localization supports the hypothesis that it functions in the transport of plastid-synthesized fatty acids to the endoplasmic reticulum. PMID:16663076

  7. Insights into the Inhibition of the p90 Ribosomal S6 Kinase (RSK) by the Flavonol Glycoside SL0101 from the 1.5 Å Crystal Structure of the N-Terminal Domain of RSK2 with Bound Inhibitor

    SciTech Connect

    Utepbergenov, Darkhan; Derewenda, Urszula; Olekhnovich, Natalya; Szukalska, Gabriela; Banerjee, Budhaditya; Hilinski, Michael K.; Lannigan, Deborah A.; Stukenberg, P. Todd; Derewenda, Zygmunt S.

    2012-09-11

    The p90 ribosomal S6 family of kinases (RSK) are potential drug targets, due to their involvement in cancer and other pathologies. There are currently only two known selective inhibitors of RSK, but the basis for selectivity is not known. One of these inhibitors is a naturally occurring kaempferol-a-l-diacetylrhamnoside, SL0101. Here, we report the crystal structure of the complex of the N-terminal kinase domain of the RSK2 isoform with SL0101 at 1.5 {angstrom} resolution. The refined atomic model reveals unprecedented structural reorganization of the protein moiety, as compared to the nucleotide-bound form. The entire N-lobe, the hinge region, and the aD-helix undergo dramatic conformational changes resulting in a rearrangement of the nucleotide binding site with concomitant formation of a highly hydrophobic pocket spatially suited to accommodate SL0101. These unexpected results will be invaluable in further optimization of the SL0101 scaffold as a promising lead for a novel class of kinase inhibitors.

  8. FlavonQ: An Automated Data Processing Tool for Profiling Flavone/flavonol Glycosides Using Ultra High-performance Liquid Chromatography Diode Array Detection and High-Resolution Accurate-Mass Mass Spectrometry (UHPLC HRAM-MS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavonoids are well-known for their health benefits and can be found in nearly every plant. There are more than 5,000 known flavonoids existing in foods. Profiling flavonoids in natural products poses great challenges due to the diversity of flavonoids, the lack of commercially available standards, ...

  9. Stereoelectronic basis for the kinetic resolution of N-heterocycles with chiral acylating reagents.

    PubMed

    Hsieh, Sheng-Ying; Wanner, Benedikt; Wheeler, Philip; Beauchemin, André M; Rovis, Tomislav; Bode, Jeffrey W

    2014-06-10

    The kinetic resolution of N-heterocycles with chiral acylating agents reveals a previously unrecognized stereoelectronic effect in amine acylation. Combined with a new achiral hydroxamate, this effect makes possible the resolution of various N-heterocycles by using easily prepared reagents. A transition-state model to rationalize the stereochemical outcome of this kinetic resolution is also proposed.

  10. ACBP and cholesterol differentially alter fatty acyl CoA utilization by microsomal ACAT.

    PubMed

    Chao, Hsu; Zhou, Minglong; McIntosh, Avery; Schroeder, Friedhelm; Kier, Ann B

    2003-01-01

    Microsomal acyl CoA:cholesterol acyltransferase (ACAT) is stimulated in vitro and/or in intact cells by proteins that bind and transfer both substrates, cholesterol, and fatty acyl CoA. To resolve the role of fatty acyl CoA binding independent of cholesterol binding/transfer, a protein that exclusively binds fatty acyl CoA (acyl CoA binding protein, ACBP) was compared. ACBP contains an endoplasmic reticulum retention motif and significantly colocalized with acyl-CoA cholesteryl acyltransferase 2 (ACAT2) and endoplasmic reticulum markers in L-cell fibroblasts and hepatoma cells, respectively. In the presence of exogenous cholesterol, ACAT was stimulated in the order: ACBP > sterol carrier protein-2 (SCP-2) > liver fatty acid binding protein (L-FABP). Stimulation was in the same order as the relative affinities of the proteins for fatty acyl CoA. In contrast, in the absence of exogenous cholesterol, these proteins inhibited microsomal ACAT, but in the same order: ACBP > SCP-2 > L-FABP. The extracellular protein BSA stimulated microsomal ACAT regardless of the presence or absence of exogenous cholesterol. Thus, ACBP was the most potent intracellular fatty acyl CoA binding protein in differentially modulating the activity of microsomal ACAT to form cholesteryl esters independent of cholesterol binding/transfer ability.

  11. Structural properties of pepsin-solubilized collagen acylated by lauroyl chloride along with succinic anhydride.

    PubMed

    Li, Conghu; Tian, Zhenhua; Liu, Wentao; Li, Guoying

    2015-10-01

    The structural properties of pepsin-solubilized calf skin collagen acylated by lauroyl chloride along with succinic anhydride were investigated in this paper. Compared with native collagen, acylated collagen retained the unique triple helix conformation, as determined by amino acid analysis, circular dichroism and X-ray diffraction. Meanwhile, the thermostability of acylated collagen using thermogravimetric measurements was enhanced as the residual weight increased by 5%. With the temperature increased from 25 to 115 °C, the secondary structure of native and acylated collagens using Fourier transform infrared spectroscopy measurements was destroyed since the intensity of the major amide bands decreased and the positions of the major amide bands shifted to lower wavenumber, respectively. Meanwhile, two-dimensional correlation spectroscopy revealed that the most sensitive bands for acylated and native collagens were amide I and II bands, respectively. Additionally, the corresponding order of the groups between native and acylated collagens was different and the correlation degree for acylated collagen was weaker than that of native collagen, suggesting that temperature played a small influence on the conformation of acylated collagen, which might be concluded that the hydrophobic interaction improved the thermostability of collagen.

  12. Fatty acid acylation of rat brain myelin proteolipid protein in vitro: identification of the lipid donor.

    PubMed

    Bizzozero, O A; Lees, M B

    1986-02-01

    The immediate acyl chain donor for fatty acid esterification of proteolipid protein (PLP) was identified in an in vitro system. Rat brain total membranes, after removal of crude nuclear and mitochondrial fractions, were incubated with radioactive acyl donors, extracted with chloroform/methanol, and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the presence of [3H]palmitic acid, CoA, ATP, and Mg2+, acylation of endogenous PLP occurred at a linear rate for at least 2 h. The radioactivity was associated with the protein via an ester linkage, mainly as palmitic acid. Omission of ATP, CoA, Mg2+, or all three reduced fatty acid incorporation into PLP to 44, 27, 8, and 4%, respectively, of the values in the complete system. Incubation of the membrane fraction with [3H]palmitoyl-CoA in the absence of CoA and ATP led to highly labeled PLP. These data demonstrate that activation of free fatty acid is required for acylation. Phospholipids and glycolipids were not able to acylate the PLP directly. Finally, when isolated myelin was incubated with [3H]palmitoyl-CoA in the absence of cofactors, only PLP was labeled, thus confirming the identity of palmitoyl-CoA as the direct acyl chain donor and suggesting that the acylating activity and the PLP pool available for acylation are both in the myelin.

  13. Ortho C-H Acylation of Aryl Iodides by Palladium/Norbornene Catalysis.

    PubMed

    Dong, Zhe; Wang, Jianchun; Ren, Zhi; Dong, Guangbin

    2015-10-19

    Reported herein is a palladium/norbornene-catalyzed ortho-arene acylation of aryl iodides by a Catellani-type C-H functionalization. This transformation is enabled by isopropyl carbonate anhydrides, which serve as both an acyl cation equivalent and a hydride source.

  14. The Role of Mitochondrial Non-Enzymatic Protein Acylation in Ageing

    PubMed Central

    Hong, Shin Yee; Ng, Li Theng; Ng, Li Fang; Inoue, Takao; Tolwinski, Nicholas S.; Hagen, Thilo; Gruber, Jan

    2016-01-01

    In recent years, various large-scale proteomic studies have demonstrated that mitochondrial proteins are highly acylated, most commonly by addition of acetyl and succinyl groups. These acyl modifications may be enzyme catalysed but can also be driven non-enzymatically. The latter mechanism is promoted in mitochondria due to the nature of the mitochondrial microenvironment, which is alkaline and contains high concentrations of acyl-CoA species. Protein acylation may modify enzyme activity, typically inhibiting it. We posited that organismal ageing might be accompanied by an accumulation of acylated proteins, especially in mitochondria, and that this might compromise mitochondrial function and contribute to ageing. In this study, we used R. norvegicus, C. elegans and D. melanogaster to compare the acylation status of mitochondrial proteins between young and old animals. We observed a specific age-dependent increase in protein succinylation in worms and flies but not in rat. Rats have two substrate-specific mitochondrial deacylases, SIRT3 and SIRT5 while both flies and worms lack these enzymes. We propose that accumulation of mitochondrial protein acylation contributes to age-dependent mitochondrial functional decline and that SIRT3 and SIRT5 enzymes may promote longevity through regulation of mitochondrial protein acylation during ageing. PMID:28033361

  15. Selective acylation of plasma membrane proteins of Mycoplasma agalactiae: the causal agent of agalactia.

    PubMed

    Le Hénaff, M; Guéguen, M M; Fontenelle, C

    2000-01-01

    Revealed by in vivo labeling with (14)C-palmitic acid, about 15 acylated proteins were identified in the plasma membrane of Mycoplasma agalactiae (type strain PG2), including the major component p40. Triton X-114 phase partitioning and Western blotting demonstrated the amphiphilic properties of the acyl proteins and showed that they were also antigenic components. Chemical analyses of fatty acids bound to proteins revealed the following selectivity order within acylation: stearic acid (18:0) > linoleic acid (18:2c) approximately palmitic acid (16:0) > oleic acid (18:1c) > myristic acid (14:0), with 16:0 and 18:1c preferred for the O-acylation and 18:0 for the N-acylation. The ratio [O-ester- + amide-bound acyl chains]/O-ester-linked chains being close to 1.4 as well as the presence of S-glycerylcysteine suggest that acyl proteins in M. agalactiae are true lipoproteins containing N-acyl diacyl glycerylcysteine, probably processed by a mechanism analogous to that described for Gram-negative eubacteria.

  16. Quantitative analysis of the flavonoid glycosides and terpene trilactones in the extract of Ginkgo biloba and evaluation of their inhibitory activity towards fibril formation of β-amyloid peptide.

    PubMed

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

    2014-04-10

    The standard extract of Ginkgo biloba leaves (EGb761) is used clinically in Europe for the symptomatic treatment of impaired cerebral function in primary degenerative dementia syndromes, and the results of numerous in vivo and in vitro studies have supported such clinical use. The abnormal production and aggregation of amyloid β peptide (Aβ) and the deposition of fibrils in the brain are regarded as key steps in the onset of Alzheimer's Disease (AD), and the inhibition of Aβ aggregation and destabilization of the preformed fibrils represent viable approaches for the prevention and treatment of AD. Flavonoid glycosides and terpene trilactones (TTLs) are the two main components of EGb761 which represent 24 and 6% of the overall content, respectively. In our research, seven abundant flavonoid glycosides 1-7 were isolated from the extract of Ginkgo biloba leaves and characterized by spectroscopic analysis. Furthermore, an ultra-high performance liquid chromatography method was established for the simultaneous quantification of these seven flavonoids. The inhibitory activities of these flavonoids, as well as four TTLs, i.e., ginkgolides A, B, and C and bilobalide (compounds 8-11), were evaluated towards Aβ42 fibril formation using a thioflavin T fluorescence assay. It was found that three flavonoids 1, 3 and 4 exhibited moderate inhibitory activities, whereas the other four flavonoids 2, 5, 6 and 7, as well as the four terpene trilactones, showed poor activity. This is the first report of the inhibition of Aβ fibril formation of two characteristic acylated flavonoid glycosides 6, 7 in Ginkgo leaves, on the basis of which the structure-activity relationship of these flavonoids 1-7 was discussed.

  17. Impact of intracerebroventricular obestatin on plasma acyl ghrelin, des-acyl ghrelin and nesfatin-1 levels, and on gastric emptying in rats.

    PubMed

    Chen, Chih-Yen; Lee, Wei-Jei; Chong, Keong; Lee, Shou-Dong; Liao, You-Di

    2012-07-01

    Obestatin, which is a putative 23-amino-acid peptide, is derived from the C-terminal part of the mammalian preproghrelin gene. Nesfatin-1 mRNA is co-expressed with ghrelin in gastric endocrine X/A-like cells; therefore, nesfatin-1 may also interact with preproghrelin gene products in the stomach. In this study, we investigated the impact of obestatin on the plasma levels of acyl ghrelin, des-acyl ghrelin and nesfatin-1, and on the gastric emptying of a solid nutrient meal 2 h after an intracerebroventricular (ICV) injection in conscious, fasted rats. The rats were implanted with ICV catheters. Plasma levels of acyl ghrelin, des-acyl ghrelin and nesfatin-1, expected to be co-expressed with obestatin, were measured, whereas the human/rat corticotropin-releasing factor (h/rCRF) was applied as an inhibitor of gastric emptying. The ICV administration of obestatin (0.1, 0.3 and 1.0 nmol/rat) did not modify the plasma acyl ghrelin and des-acyl ghrelin levels, the acyl ghrelin/des-acyl ghrelin ratio and nesfatin-1 concentrations. The ICV acute administration of obestatin had no influence on the 2-h rate of gastric emptying of a solid nutrient meal, but the ICV h/rCRF injection delayed it. The weight of food ingested 1 h before ICV injection significantly, but negatively correlated with the gastric emptying of a solid nutrient meal. Our study indicates that the ICV injection of obestatin does not change the 2-h rate of gastric emptying of a solid nutrient meal and the relatively weak interrelationships between ghrelin gene products and nesfatin-1. However, the weight of the ingested food negatively affects the gastric emptying of a solid nutrient meal in conscious, fasted rats.

  18. Acylation of salmon calcitonin modulates in vitro intestinal peptide flux through membrane permeability enhancement.

    PubMed

    Trier, Sofie; Linderoth, Lars; Bjerregaard, Simon; Strauss, Holger M; Rahbek, Ulrik L; Andresen, Thomas L

    2015-10-01

    Acylation of peptide drugs with fatty acid chains has proven beneficial for prolonging systemic circulation, as well as increasing enzymatic stability and interactions with lipid cell membranes. Thus, acylation offers several potential benefits for oral delivery of therapeutic peptides, and we hypothesize that tailoring the acylation may be used to optimize intestinal translocation. This work aims to characterize acylated analogues of the therapeutic peptide salmon calcitonin (sCT), which lowers blood calcium, by systematically increasing acyl chain length at two positions, in order to elucidate its influence on intestinal cell translocation and membrane interaction. We find that acylation drastically increases in vitro intestinal peptide flux and confers a transient permeability enhancing effect on the cell layer. The analogues permeabilize model lipid membranes, indicating that the effect is due to a solubilization of the cell membrane, similar to transcellular oral permeation enhancers. The effect is dependent on pH, with larger effect at lower pH, and is impacted by acylation chain length and position. Compared to the unacylated peptide backbone, N-terminal acylation with a short chain provides 6- or 9-fold increase in peptide translocation at pH 7.4 and 5.5, respectively. Prolonging the chain length appears to hamper translocation, possibly due to self-association or aggregation, although the long chain acylated analogues remain superior to the unacylated peptide. For K(18)-acylation a short chain provides a moderate improvement, whereas medium and long chain analogues are highly efficient, with a 12-fold increase in permeability compared to the unacylated peptide backbone, on par with currently employed oral permeation enhancers. For K(18)-acylation the medium chain acylation appears to be optimal, as elongating the chain causes greater binding to the cell membrane but similar permeability, and we speculate that increasing the chain length further may

  19. Non-enzymatic protein acylation as a carbon stress regulated by sirtuin deacylases

    PubMed Central

    Wagner, Gregory R.; Hirschey, Matthew D.

    2014-01-01

    Cellular proteins are decorated with a wide range of acetyl and other acyl modifications. Many studies have demonstrated regulation of site-specific acetylation by acetyltransferases and deacetylases. Acylation is emerging as a new type of lysine modification, but less is known about its overall regulatory role. Furthermore, the mechanisms of lysine acylation, its overlap with protein acetylation, and how it influences cellular function are major unanswered questions in the field. In this review, we discuss the known roles of acetyltransferases and deacetylases, and the sirtuins as a conserved family of NAD+-dependent protein deacylases that are important for response to cellular stress and homeostasis. We also consider the evidence for an emerging idea of non-enzymatic protein acylation. Finally, we put forward the hypothesis that protein acylation is a form of protein “carbon stress”, that the deacylases evolved to remove as a part of a global protein quality control network. PMID:24725594

  20. Antimicrobial and selected in vitro enzyme inhibitory effects of leaf extracts, flavonols and indole alkaloids isolated from Croton menyharthii.

    PubMed

    Aderogba, Mutalib A; Ndhlala, Ashwell R; Rengasamy, Kannan R R; Van Staden, Johannes

    2013-10-11

    Croton species are used in folk medicine in the management of infections, inflammation and oxidative stress-related diseases. In order to isolate, characterize and evaluate the bioactive constituents of Croton menyharthii Pax leaf extracts, repeated column fractionation of the ethyl acetate fraction from a 20% aqueous methanol crude extract afforded three flavonols identified by NMR (1D and 2D) spectroscopic methods as myricetrin-3-O-rhamnoside (myricetrin, 1), quercetin-3-O-rhamnoside (2) and quercetin (3) along with an indole alkaloid, (E)-N-(4-hydroxycinnamoyl)-5-hydroxytryptamine, [trans-N-(p-coumaroyl) serotonin, 4]. All the compounds are reported from the leaf extract of this plant for the first time. The crude extracts, four solvent fractions (hexane, DCM, ethyl acetate and butanol) and isolated compounds obtained from the leaves were evaluated for their inhibitory effects on selected bacteria, a fungus (Candida albicans), cyclooxygenase (COX-2), α-glucosidase and acetylcholinesterase (AChE). Amongst the compounds, quercetin (3) was the most active against Bacillus subtilis and Candida albicans while myricetrin-3-O-rhamnoside (1) and trans-N-(p-coumaroyl) serotonin (4) were the most active compounds against Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus. The inhibitory activity of myricetrin-3-O-rhamnoside (1) against COX-2 was insignificant while that of the other three compounds 2-4 was low. The AChE inhibitory activity of the alkaloid, trans-N-(p-coumaroyl) serotonin was high, with a percentage inhibitory activity of 72.6% and an IC50 value of 15.0 µg/mL. The rest of the compounds only had moderate activity. Croton menyharthii leaf extracts and isolated compounds inhibit α-glucosidase at very low IC50 values compared to the synthetic drug acarbose. Structure activity relationship of the isolated flavonols 1-3 is briefly outlined. Compounds 1-4 and the leaf extracts exhibited a broad spectrum of activities. This validates the