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1

Flavonoid composition and antioxidant activity of tree peony (Paeonia section moutan) yellow flowers.  

PubMed

Tree peony flowers are edible and traditional Chinese medicine materials. In the present study, 26 flavonoids were identified and quantified in yellow flowers of tree peony by high-performance liquid chromatography with diode array detector (HPLC-DAD) and by HPLC-electrospray ionization-mass spectrometry (HPLC-ESI-MS). Seventeen of them were first reported in flowers of tree peony, and glycosides of kaempferol, luteolin, and apigenin as well as isosalipurposide were the main flavonoids investigated. Furthermore, the petal extracts showed high antioxidant activity according to DPPH*, ABTS*(+), and OH* scavenging assays and ferric reducing antioxidant power assay. There were significant correlations between antioxidant activity and both the total polyphenol content (determined by Folin-Ciocalteu method) and the total content of quercetin, kaempferol, and luteolin glycosides. This work is valuable for elucidation of phenolic composition in tree peony flowers and for further utilization of them as functional food and medicine materials. PMID:19711909

Li, Chonghui; Du, Hui; Wang, Liangsheng; Shu, Qingyan; Zheng, Yuanrun; Xu, Yanjun; Zhang, Jingjing; Zhang, Jie; Yang, Ruizhen; Ge, Yuxuan

2009-09-23

2

Taxonomy, Geographic Distribution and Ecological Habitats of Tree Peonies  

Microsoft Academic Search

Tree peonies belong to Paeonia L. section Moutan DC., Paeoniaceae. All wild tree peonies are endemic to China, which is also the first domestication place of cultivated tree\\u000a peonies. A new taxonomic system of Sect. Moutan was proposed by Hong and Pan (Hong D.Y. and Pan K.Y. 1999a. Acta Phytotax. Sin. 37: 351–368; 1999b). In their system eight\\u000a species, of

Zhi-Qin Zhou

2006-01-01

3

DNA barcoding: species delimitation in tree peonies.  

PubMed

Delimitations of species are crucial for correct and precise identification of taxa. Unfortunately "species" is more a subjective than an objective concept in taxonomic practice due to difficulties in revealing patterns of infra- or inter-specific variations. Molecular phylogenetic studies at the population level solve this problem and lay a sound foundation for DNA barcoding. In this paper we exemplify the necessity of adopting a phylogenetic concept of species in DNA barcoding for tree peonies (Paeonia sect. Moutan). We used 40 samples representing all known populations of rare and endangered species and several populations of widely distributed tree peonies. All currently recognized species and major variants have been included in this study. Four chloroplast gene fragments, i.e. ndhF, rps16-trnQ, trnL-F and trnS-G (a total of 5040 characters, 96 variable and 69 parsimony-informative characters) and one variable and single-copy nuclear GPAT gene fragment (2093-2197 bp, 279 variable and 148 parsimony-informative characters) were used to construct phylogenetic relationships among the taxa. The evolutionary lineages revealed by the nuclear gene and the chloroplast genes are inconsistent with the current circumscriptions of P. decomposita, P. jishanensis, P. qiui, and P. rockii based on morphology. The inconsistencies come from (1) significant chloroplast gene divergence but little nuclear GPAT gene divergence among population systems of P. decomposita + P. rockii, and (2) well-diverged nuclear GPAT gene but little chloroplast gene divergence between P. jishanensis and P. qiui. The incongruence of the phylogenies based on the chloroplast genes and the nuclear GPAT gene is probably due to the chloroplast capture event in evolutionary history, as no reproductive barriers exist to prevent inter-specific hybridization. We also evaluated the suitability of these genes for use as DNA barcodes for tree peonies. The variability of chloroplast genes among well-defined species or population systems of a species complex is 4.82 times the figure within the groups, and the GPAT gene is twice as variable between the groups as within the groups. The number of completely divergent sites is sufficient to mark the two subsections, the two species in subsection Delavayanae, and the well-divergent species in subsection Vaginatae. But the genes currently used either from the chloroplast genome or from the nuclear genome alone cannot correctly assign samples of P. decomposita, P. jishanensis, P. qiui, or P. rockii to the species as currently defined. We conclude that (1) DNA barcoding should be based on prior phylogenetic studies to understand the evolutionary lineages and how well the taxonomic species correspond to the lineages; (2) it is unlikely to find a single short fragment as a barcode for every plant and such a fragment could result in misidentification when a chloroplast capture event happened in the evolutionary history of plants like tree peonies; and (3) we suggest striving for a universal marker at the familial level and locally universal barcodes within a family instead of looking for a universal barcode for all plants. PMID:19557335

ZHANG, JinMei; WANG, JianXiu; XIA, Tao; ZHOU, ShiLiang

2009-06-26

4

First Report of Tobacco Rattle Virus in Peony in Alaska  

Technology Transfer Automated Retrieval System (TEKTRAN)

In 2007, scattered peony (Paeonia lactiflora ‘Sarah Bernhardt’) plants cultivated on plots at the University of Alaska Experimental Station in Fairbanks, Alaska, contained distinct leaf ringspot patterns. Leaf samples from symptomatic plants were collected in early July (6 plants) and late September...

5

Pyrethrin and Gallotannin in the Flowers of Peony  

Microsoft Academic Search

FROM a light petroleum extract of dried petals of peony (Peonia albiflora Pall.) an oily substance (74.08 per cent C, 9.94 per cent H) was isolated by means of nitromethane extraction. It comprises 0.13 per cent of the dry weight of petals and 18 per cent of light petroleum extracts and shows in the ultraviolet spectral region maxima at 227

I. Chmielewska; Z. Kasprzyk

1962-01-01

6

Microsatellite markers in the tree peony, Paeonia suffruticosa (Paeoniaceae).  

PubMed

• Premise of the study: Microsatellite primers were developed in the tree peony, Paeonia suffruticosa, to perform paternity tests as well as assignment to variety in special Austrian collections. • Methods and Results: Using SSR-enriched libraries and EST-mining, 8 polymorphic primer sets were identified in Austrian collections of Paeonia sect. Moutan DC. The primers amplified di- and trinucleotide repeats with 2-6 alleles per locus. All primers also amplified in P. ostii, P. pontaninii var. trolloides, P. delavayi, and P. lutea, and in the herbaceous species P. peregrina and P. tenuifolia (Paeonia sect. Paeon). • Conclusions: These results show the usefulness of primers in P. suffruticosa for population genetic studies and their ability to cross amplify in related taxa across the genus. PMID:21622456

Homolka, Andreas; Berenyi, Maria; Burg, Kornel; Kopecky, Dieter; Fluch, Silvia

2010-05-24

7

Brown spot disease of tree peony caused by Cylindrocladium canadense in China  

Microsoft Academic Search

In the summer of 2008, a brown spot disease in cultivated tree peony Paeonia suffruticosa was found in Shandong Province, China. The causal fungus was isolated from diseased leaves and identified as Cylindrocladium canadense J.C. Kang, Crous & C.L. Schoch based on morphological and molecular phylogenetic studies. Inoculation of the peony leaves\\u000a with the isolated fungus resulted in similar symptoms,

N. Li; X. L. Zhao; A. X. Liu; H. X. Liu

2010-01-01

8

Two EST-derived marker systems for cultivar identification in tree peony.  

PubMed

Tree peony (Paeonia suffruticosa Andrews), a woody deciduous shrub, belongs to the section Moutan DC. in the genus of Paeonia of the Paeoniaceae family. To increase the efficiency of breeding, two EST-derived marker systems were developed based on a tree peony expressed sequence tag (EST) database. Using target region amplification polymorphism (TRAP), 19 of 39 primer pairs showed good amplification for 56 accessions with amplicons ranging from 120 to 3,000 bp long, among which 99.3% were polymorphic. In contrast, 7 of 21 primer pairs demonstrated adequate amplification with clear bands for simple sequence repeats (SSRs) developed from ESTs, and a total of 33 alleles were found in 56 accessions. The similarity matrices generated by TRAP and EST-SSR markers were compared, and the Mantel test (r = 0.57778, P = 0.0020) showed a moderate correlation between the two types of molecular markers. TRAP markers were suitable for DNA fingerprinting and EST-SSR markers were more appropriate for discriminating synonyms (the same cultivars with different names due to limited information exchanged among different geographic areas). The two sets of EST-derived markers will be used further for genetic linkage map construction and quantitative trait locus detection in tree peony. PMID:21987120

Zhang, J J; Shu, Q Y; Liu, Z A; Ren, H X; Wang, L S; De Keyser, E

2011-10-11

9

Herbaceous Peony (Paeonia lactiflora Pall.) as an Alternative Source of Oleanolic and Ursolic Acids  

PubMed Central

Oleanolic acid (OA) and ursolic acid (UA) have been proven to possess many biological activities, and much attention is focused on the search for plants which are rich in OA and UA. In this report, the OA and UA accumulation characteristics were investigated in 47 cultivars of Chinese herbaceous peony (Paeonia lactiflora Pall.) and were followed in three cultivars over different developmental stages as measured by high performance liquid chromatography (HPLC). OA and UA levels in leaves and stems demonstrated an overall upward trend from May 1 to September 15 except for UA in the leaves of “Hong Feng”. The maximum values of OA and UA in leaves of “Yangfei Chu Yu”, “Fen Zhu Pan” and “Hong Feng” were 852.98, 575.60, 290.48 ?g/g FW and 924.94, 827.36, 432.67 ?g/g FW, respectively. The maximum values of OA and UA in stems of “Yangfei Chu Yu”, “Fen Zhu Pan” and “Hong Feng” were 359.28, 90.49, 43.90 ?g/g FW and 326.86, 82.25, 56.63 ?g/g FW, respectively. OA and UA contents in leaves of 47 different herbaceous peony cultivars ranged from 66.73–618.12 and 36.23–665.14 ?g/g FW, respectively, with average values of 171.62 and 227.57 ?g/g FW, respectively. The results suggested that the aboveground parts of herbaceous peony may be used as an alternative source of OA and UA for medicinal purposes in addition to its ornamental purposes.

Zhou, Chunhua; Zhang, Ying; Sheng, Yanle; Zhao, Daqiu; Lv, Sansan; Hu, Yue; Tao, Jun

2011-01-01

10

Bioinspired peony-like beta-Ni(OH)2 nanostructures with enhanced electrochemical activity and superhydrophobicity.  

PubMed

Constructing complex nanostructures has become increasingly important in the development of hydrogen storage, self-cleaning materials, and the formation of chiral branched nanowires. Several approaches have been developed to generate complex nanostructures, which have led to novel applications. Combining biology and nanotechnology through the utilization of biomolecules to chemically template the growth of complex nanostructures during synthesis has aroused great interest. Herein, we use a biomolecule-assisted hydrothermal method to synthesize beta-phase Ni(OH)(2) peony-like complex nanostructures with second-order structure nanoplate structure. The novel beta-Ni(OH)(2) nanostructures exhibit high-power Ni/MH battery performance, close to the theoretical capacity of Ni(OH)(2), as well as controlled wetting behavior. We demonstrate that this bioinspired route to generate a complex nanostructure has applications in environmental protection and green secondary cells. This approach opens up opportunities for the synthesis and potential applications of new kinds of nanostructures. PMID:19998313

Cao, Huaqiang; Zheng, He; Liu, Kaiyu; Warner, Jamie H

2010-02-01

11

Identification of differentially expressed genes associated with bud dormancy release in tree peony ( Paeonia suffruticosa ) by suppression subtractive hybridization  

Microsoft Academic Search

A subtractive cDNA library was developed to study genes associated with bud dormancy release in tree peonies. In order to\\u000a identify genes that are highly expressed in buds released from dormancy, 588 clones were examined by differential screening.\\u000a Of these, 185 clones were selected to be sequenced. A total of 37 unique sequences were obtained of which only 31 sequences

Xin Huang; Guo-sheng Zheng; Si-lan Dai; Shu-peng Gai

2008-01-01

12

The involvement of mitochondrial phosphate transporter in accelerating bud dormancy release during chilling treatment of tree peony ( Paeonia suffruticosa )  

Microsoft Academic Search

A cDNA clone was isolated from tree peony (Paeonia suffruticosa) subtractive cDNA library of burst buds and characterized with regard to its sequence, expression in response to chilling\\u000a treatment during the release of bud dormancy, and its function in transgenic Arabidopsis thaliana. The clone, designated as PsMPT, contains 1,615 nucleotides with an open reading frame of 1,119 nucleotides, and the

Xin Huang; Wei Zhu; Silan Dai; Shupeng Gai; Guosheng Zheng; Chengchao Zheng

2008-01-01

13

Naturally occurring cardiac glycosides.  

PubMed

Cardiac glycoside poisoning from the ingestion of plants, particularly of oleanders, occurs with reasonable frequency in tropical and subtropical areas. We have assessed a variety of plant specimens for their cardiac glycoside content by means of radioimmunoassays with antibodies that differ in their specificity for cardiac glycosides. Significant amounts of immunoreactive cardiac glycoside were found to be present in the ornamental shrubs: yellow oleander (Thevetia peruviana); oleander (Nerium oleander); wintersweet (Carissa spectabilis); bushman's poison (Carissa acokanthera); sea-mango (Cerbera manghas); and frangipani (Plumeria rubra); and in the milkweeds: redheaded cotton-bush (Asclepias curassavica); balloon cotton (Asclepias fruiticosa); king's crown (Calotropis procera); and rubber vine (Cryptostegia grandifolia). The venom gland of the cane toad (Bufo marinus) also contained large quantities of cardiac glycosides. The competitive immunoassay method permits the rapid screening of specimens that are suspected to contain cardiac glycosides. Awareness of the existence of these plant and animal toxins and their dangers allows them to be avoided and poisoning prevented. The method is also useful for the confirmation of the presence of cardiac glycosides in serum in cases of poisoning. PMID:3086679

Radford, D J; Gillies, A D; Hinds, J A; Duffy, P

1986-05-12

14

Steroidal glycosides from Agave utahensis.  

PubMed

Three new spirostanol glycosides (1-3) and a new furostanol glycoside (4), together with two known spirostanol glycosides (5 and 6) were isolated from the whole plants of Agave utahensis (Agavaceae). The structures of the new compounds were determined by spectroscopic analysis and the results of hydrolytic cleavage. PMID:17202720

Yokosuka, Akihito; Mimaki, Yoshihiro

2007-01-01

15

Phenetics in Tree Peony Species from China by Flower Pigment Cluster Analysis  

Microsoft Academic Search

Paeonia   section Moutan DC. (fifteen accessions) from China. As the pigment markers, five anthocyanins together with three flavone and three flavonol\\u000a aglycones were used. Principal component analysis (PCA) provided five eigenvectors from nineteen pigment patterns, in which\\u000a peonidin and cyanidin as well as the types of glycosides greatly influenced the first factor, Z\\u000a 1. The Euclidean distances of standardized values

Liang-Sheng Wang; Fumio Hashimoto; Aya Shiraishi; Noriaki Aoki; Jia-Jue Li; Keiichi Shimizu; Yusuke Sakata

2001-01-01

16

Pregnane glycosides from Sansevieria trifasciata  

Microsoft Academic Search

Phytochemical analysis of the whole plant of Sansevieria trifasciata, one of the most common Agavaceae plants, has resulted in the isolation of four new pregnane glycosides. Their structures have been determined by spectroscopic analysis and acid- and alkaline-catalysed hydrolysis to be 1?,3?-dihydroxypregna-5,16-dien-20-one glycosides. This is believed to be the first report of the isolation of the pregnane glycosides from a

Yoshihiro Mimaki; Toshihiro Inoue; Minpei Kuroda; Yutaka Sashida

1997-01-01

17

Pregnane glycosides from Sansevieria trifasciata.  

PubMed

Phytochemical analysis of the whole plant of Sansevieria trifasciata, one of the most common Agavaceae plants, has resulted in the isolation of four new pregnane glycosides. Their structures have been determined by spectroscopic analysis and acid- and alkaline-catalysed hydrolysis to be 1 beta,3 beta-dihydroxypregna-5,16-dien-20-one glycosides. This is believed to be the first report of the isolation of the pregnane glycosides from a plant of the family Agavaceae. PMID:8983214

Mimaki, Y; Inoue, T; Kuroda, M; Sashida, Y

1997-01-01

18

Immunological functions of steryl glycosides.  

PubMed

Steryl glycosides, sterols glycosylated at the 3?-hydroxy group, have been widely found in plants, algae, and fungi, but are rare in bacteria and animals. Glycosylation of sterols is known to modify properties of the cell membrane and confer resistance against stresses by freezing or heat-shock on cells. Furthermore, accumulating evidence obtained from recent research suggests important biological functions of steryl glycosides, including regulation of host defenses against pathogens, lipid metabolism, and developmental events. This review is focused on the immunological functions of steryl glycosides, such as modulation of host immune functions upon exposure to cholesteryl glycosides produced by pathogenic bacteria. PMID:22936327

Shimamura, Michio

2012-08-31

19

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

NASA Astrophysics Data System (ADS)

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.

K?en, Vladimír

20

Aroma glycosides from Hovenia dulsis.  

PubMed

From the fresh leaves of Hovenia dulsis var. tomentella, two new aroma glycosides named kenposide A and B have been isolated together with the known glycoside, icariside C1. Their structures were determined on the basis of chemical and spectral evidence. PMID:7764288

Yoshikawa, K; Nagai, M; Wakabayashi, M; Arihara, S

1993-11-01

21

Analysis of flavanone-7- O-glycosides in citrus juices by short-end capillary electrochromatography  

Microsoft Academic Search

The separation of the major flavanone-7-O-glycoside constituents of Citrus was carried out by isocratic reversed phase capillary electrochromatography using a 75?m i.d. silica fused column packed with 5?m ODS silica gel. In comparison to HPLC mode, capillary electrochromatography resolution of flavanone glycosides was obtained with a high selectivity factor. Optimum separation conditions were found using a mixture of ammonium formate

Claudia Desiderio; Antonella De Rossi; Massimo Sinibaldi

2005-01-01

22

Effect of marine glycosides on adenosinetriphosphatase activity.  

PubMed

Marine glycosides from the sea cucumbers Actinopyga agassizi, Holothuria atra, Bohadschia argus, Cucumaria fraudatrix, Astichopus multifidus and Thelenota ananas inhibit both Na+-K+ ATPase and Mg2+-ATPase of rat brain in vitro. The glycoside-cholesterol complex of these compounds does not influence ATPase activity. Asterosaponins from starfishes Linckia guildingi and Linckia laevigata possess a slight inhibiting effect. The triterpene glycosides from sea cucumbers are more powerful inhibitors than steroidal glycosides from starfishes. PMID:6213068

Gorshkov, B A; Gorshkova, I A; Stonik, V A; Elyakov, G B

1982-01-01

23

Effects of Inflorescence Stem Structure and Cell Wall Components on the Mechanical Strength of Inflorescence Stem in Herbaceous Peony  

PubMed Central

Herbaceous peony (Paeonia lactiflora Pall.) is a traditional famous flower, but its poor inflorescence stem quality seriously constrains the development of the cut flower. Mechanical strength is an important characteristic of stems, which not only affects plant lodging, but also plays an important role in stem bend or break. In this paper, the mechanical strength, morphological indices and microstructure of P. lactiflora development inflorescence stems were measured and observed. The results showed that the mechanical strength of inflorescence stems gradually increased, and that the diameter of inflorescence stem was a direct indicator in estimating mechanical strength. Simultaneously, with the development of inflorescence stem, the number of vascular bundles increased, the vascular bundle was arranged more densely, the sclerenchyma cell wall thickened, and the proportion of vascular bundle and pith also increased. On this basis, cellulose and lignin contents were determined, PlCesA3, PlCesA6 and PlCCoAOMT were isolated and their expression patterns were examined including PlPAL. The results showed that cellulose was not strictly correlated with the mechanical strength of inflorescence stem, and lignin had a significant impact on it. In addition, PlCesA3 and PlCesA6 were not key members in cellulose synthesis of P. lactiflora and their functions were also different, but PlPAL and PlCCoAOMT regulated the lignin synthesis of P. lactiflora. These data indicated that PlPAL and PlCCoAOMT could be applied to improve the mechanical strength of P. lactiflora inflorescence stem in genetic engineering.

Zhao, Daqiu; Han, Chenxia; Tao, Jun; Wang, Jing; Hao, Zhaojun; Geng, Qingping; Du, Bei

2012-01-01

24

Immunostimulatory effect of a composition isolated from white peony root oral liquid in the treatment of radiation-induced esophagitis  

PubMed Central

The aim of this study was to explore the immune repairing effect of a composition isolated from white peony root oral liquid (cWPROL), a traditional Chinese herbal composition, in the treatment of experimental radiation-induced esophagitis in rats. A total of 128 Wistar rats were randomly divided into eight groups, irradiated with 43 Gy 60Co ?-rays to induce esophagitis and treated by different methods. Flow cytometry, hematological analysis and immune nephelometry were used to detect the absolute numbers and percentages of CD3+, CD4+ and CD8+ T lymphocytes, numbers and classification of leukocytes, and the levels of IgG and complement C3 in the peripheral blood of the rats at each experimental time point. Following irradiation, the total number of leukocytes, absolute numbers and percentages of CD3+, CD4+ and CD8+ T lymphocytes, and levels of IgG and complement C3 in the peripheral blood of the rats were decreased. Furthermore, the total numbers of leukocytes, absolute numbers and percentages of CD3+, CD4+ and CD8+ T lymphocytes, and levels of IgG and complement C3 in the peripheral blood were higher in the administered with cWPROL by intra-esophageal perfusion compared with those in the untreated irradiated groups, but lower in the groups treated with a mixture of lidocaine hydrochloride, dexamethasone sodium phosphate and gentamicin sulfate. This study suggested that cWPROL is able to repair the impaired cellular and humoral immunity of rats with radiation-induced esophagitis.

WANG, ZHIYU; SHEN, LI; WANG, JUAN; SHAN, BAOEN; ZHANG, LI; LU, FUHE; GUO, XIUJUAN; LI, XING

2013-01-01

25

Triterpene glycosides from Schefflera octophylla.  

PubMed

In addition to 3-epi-betulinic acid, three triterpene glycosides were isolated from leaves of Schefflera octophylla. The structures of the glycosides have been determined as 28-O-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)-be ta-D- glucopyranosides of 3 alpha-hydroxy-lup-20(29)-ene-23,28-dioic acid, 3 alpha,11 alpha- dihydroxy-lup20(29)-ene-23,28-dioic acid and 3-epi-betulinic acid by spectroscopic data and chemical transformations. The last two compounds were found for the first time in the plant kingdom. PMID:1367650

Sung, T V; Steglich, W; Adam, G

1991-01-01

26

[Phenyl glycosides from Curculigo orchioides].  

PubMed

One new phenyl glycoside and two new chlorophenyl glycosides were isolated from rhizomes of Curculigo orchioides (Chinese name: Xian Mao, Hypoxidaceae). Based on HRMS, FABMS, 1H-, 13C-NMR and other spectral data as well as chemical evidence, the structures of curculigoside B, curculigine B and C were elucidated to be 2-beta-D-glucopyranosyloxy-5-hydroxybenzyl-2'-methoxy-6'-hydroxybe nzoate (I),24-dichloro-3-methyl-5-methoxy-phenol-O-beta-D-apiofuranosyl (1-6)-beta-D-glucopyanoside (III) and 2,4,6-trichloro-3-methyl-5-methoxyphenol-O-beta-D-xylopyranosyl (1-6)-beta-D-glucopyranoside (IV), respectively. PMID:1442056

Xu, J P; Xu, R S

1992-01-01

27

Lavandulifolioside B: a new phenylethanoid glycoside from the aerial parts of Stachys lavandulifolia Vahl.  

PubMed

Reversed-phase preparative HPLC analyses of the methanol extract of the aerial parts of Stachys lavandulifolia afforded a new phenylethanoid glycoside, 4,3',4'-trimethoxy-lavandulifolioside A, named lavandulifolioside B, together with three other known phenylethanoid glycosides, lavandulifolioside A, verbascoside and leucosceptoside A, and an iridoid glycoside 5-O-?-allopyranosyloxy-aucubin (5-O-?-allopyranosyl-monomelittoside). While the structures of the known compounds, except the iridoid glycoside, were established by direct comparison of their spectroscopic data with respective literature data, lavandulifolioside B and 5-O-?-allopyranosyloxy-aucubin were identified comprehensively by extensive 1D and 2D NMR analyses. The distribution of the isolated compounds within the genus Stachys has been discussed. PMID:21240755

Delazar, Abbas; Delnavazi, Mohammad R; Nahar, Lutfun; Moghadam, Sadeigh B; Mojarab, Mahdi; Gupta, Abhishek; Williams, Angela S; Mukhlesur Rahman, M; Sarker, Satyajit D

2011-01-01

28

Anticancer activity of cardiac glycosides  

PubMed Central

Retrospective clinical data indicate that cardiac glycosides (CGs), notably digoxin, prolong the survival of carcinoma patients treated with conventional chemotherapy. CGs are known to influence the immune response at multiple levels. In addition, recent results suggest that CGs trigger the immunogenic demise of cancer cells, an effect that most likely contributes to their clinical anticancer activity.

Kepp, Oliver; Menger, Laurie; Vacchelli, Erika; Adjemian, Sandy; Martins, Isabelle; Ma, Yuting; Sukkurwala, Abdul Qader; Michaud, Mickael; Galluzzi, Lorenzo; Zitvogel, Laurence; Kroemer, Guido

2012-01-01

29

Flavonoid glycosides from viscum alniformosanae  

PubMed

Two new flavonoid glycosides, (2S)-5-hydroxy-7, 3'-dimethoxyflavanone-4'-O-beta-[apiosyl (1 --> 2)]glucoside (1) and rhamnazin-4'-O-beta-[apiosyl (1 --> 2)]glucoside (2) were isolated from Viscum alniformosanae. Structures were elucidated by NMR and mass spectroscopic analysis. PMID:10543905

Chou; Ko; Lin

1999-10-01

30

Catalytic regioselective oxidation of glycosides.  

PubMed

Discrimination among equals: A catalytic method for the selective oxidation of unprotected glycosides, both monosaccharides and disaccharides, has been developed. The resulting ketosaccharides are isolated in moderate to excellent yields. This approach provides a basis for protecting-group-free synthetic transformations of carbohydrates. PMID:23780519

Jäger, Manuel; Hartmann, Marcel; de Vries, Johannes G; Minnaard, Adriaan J

2013-06-18

31

Flavanone glycosides from Alhagi pseudalhagi.  

PubMed

Two new flavanone glycosides, alhagitin and alhagidin, have been isolated from the whole plant of Alhagi pseudalhagi and their structures established respectively as naringenin 5-methyl ether 4'-glucoside and hesperitin 7-galactosyl(1-->2)[rhamnosyl(1-->6)]glucoside by chemical and spectroscopic methods. PMID:10389270

Singh, V P; Yadav, B; Pandey, V B

1999-06-01

32

Kaurane glycosides from Inula britannica  

Microsoft Academic Search

Two new diterpene glycosides have been isolated from Inula britannica and their structures established as 17-O-?-d-glucopyranosyl-16-?-H-ent-kauran-19-oic acid and 17-O-?-d-glucopyranosyl-16-?-H-ent-kauran-19-oicacid-19-O-?-d-glucopyranoside, respectively, from their spectral data, and chemical and enzymatic evidence. In addition, six known compounds were also identified.

Yu Shao; Nai-Shen Bai; Bing-Nan Zhou

1996-01-01

33

Triterpenoid glycosides from Bacopa monnieri  

Microsoft Academic Search

Two triterpenoid glycosides have been isolated along with 10 known saponins from Bacopa monnieri. Structures of the compounds have been elucidated as 3-O-[?-d-glucopyranosyl-(1?3)-?-d-glucopyranosyl] jujubogenin (1) and 3-O-[?-d-glucopyranosyl-(1?3)-?-d-glucopyranosyl] pseudojujubogenin (2) by high resolution NMR spectral data and chemical correlations. Further, the chemical compositions of bacosides A and B have been delineated.

Chillara Sivaramakrishna; Chirravuri V. Rao; Golakoti Trimurtulu; Mulabagal Vanisree; Gottumukkala V. Subbaraju

2005-01-01

34

Steroidal glycosides from Ruscus ponticus.  

PubMed

A comparative metabolite profiling of the underground parts and leaves of Ruscus ponticus was obtained by an HPLC-ESIMS(n) method, based on high-performance liquid chromatography coupled to electrospray positive ionization multistage ion trap mass spectrometry. The careful study of HPLC-ESIMS(n) fragmentation pattern of each chromatographic peak, in particular the identification of diagnostic product ions, allowed us to get a rapid screening of saponins belonging to different classes, such as dehydrated/or not furostanol, spirostanol and pregnane glycosides, and to promptly highlight similarities and differences between the two plant parts. This approach, followed by isolation and structure elucidation by 1D- and 2D-NMR experiments, led to the identification of eleven saponins from the underground parts, of which two dehydrated furostanol glycosides and one new vespertilin derivative, and nine saponins from R. ponticus leaves, never reported previously. The achieved results highlighted a clean prevalence of furostanol glycoside derivatives in R. ponticus leaves rather in the underground parts of the plant, which showed a wider structure variety. In particular, the occurrence of dehydrated furostanol derivatives, for the first time isolated from a Ruscus species, is an unusual finding which makes unique the saponins profile of R. ponticus. PMID:21354581

Napolitano, Assunta; Muzashvili, Tamar; Perrone, Angela; Pizza, Cosimo; Kemertelidze, Ether; Piacente, Sonia

2011-02-26

35

Metabolism of tomato steroidal glycosides in humans.  

PubMed

Pregnane glycosides have been isolated in small amounts, along with the major components furostanol and spirostanol glycosides, from Dioscoreaceae, Taccaceae, and Solanaceae, suggesting that pregnane glycosides might be biosynthesized from furostanol and spirostanol glycosides. Recently, commercial natural foods composed of diosgenin have been used for the treatment of diseases such as osteoporosis and premenstrual syndrome in women. It is anticipated that diosgenin would be metabolized into a type of steroidal hormone, for instance progesterone, however, this metabolism has not been confirmed. Therefore, we have examined the metabolites in the urine of subjects who ingested tomatoes, which contain a considerable amount of the steroidal glycoside esculeoside A. The occurrence of steroidal hormones in the metabolites has been recognized. It has been proven that when a steroidal glycoside is administered, it is partly metabolized into a type of steroidal hormone exhibiting various physiological activities. PMID:16946542

Noguchi, Eishin; Fujiwara, Yukio; Matsushita, Sayaka; Ikeda, Tsuyoshi; Ono, Masateru; Nohara, Toshihiro

2006-09-01

36

Alleviating coking in ethanol steam reforming by co-loading binary oxides Ni-M (M=Ag, Cu, Mn) on peony-like ceria  

NASA Astrophysics Data System (ADS)

Previously, hydrothermally prepared mesoporous peony-like ceria (PCO) material was shown to exhibit superior catalytic properties for CO oxidation and ethanol reforming. Ni supported PCO had been shown to have high activity for ethanol steam reforming at low temperature. In this work, Ag, Cu and Mn is co-loaded with Ni on PCO catalysts by impregnation method. The catalysts were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and a combined thermogravimetry, differential scanning calorimetry, and mass spectrometry (TG-DSC-MS). It was found that all the catalysts gave 100% ethanol conversion above ca. 300°C and exhibited similar H2 yield. It is found that the severe coking problem for the Ni-loaded PCO catalyst was alleviated significantly if Ag, Cu or Mn is co-loaded. Among them, the addition of Mn is the most effective in reducing carbon formation.

Xian, C. N.; Li, J. G.; Li, H.; Chen, L. Q.; Sun, J.; Lee, J. S.

2011-06-01

37

Benzyl Benzoate Glycosides from Oligoneuron rigidum.  

PubMed

Two new benzyl benzoate glycosides were isolated from the leaves and stems of the native North American prairie plant Oligoneuron rigidum (stiff goldenrod). The glycosides were isolated as a mixture of benzoate and acetate esters, which were subjected to mild base hydrolysis to facilitate full structural characterization using LCMSMS and 1D and 2D NMR data. PMID:23121124

Miesner, Sarah; Frosch, Holly; Kindscher, Kelly; Tichy, Shane; Manfredi, Kirk P

2012-11-01

38

Two phenolic glycosides from Curculigo orchioides Gaertn.  

PubMed

One new glycoside derivative from syringic acid and one new phenol glycoside, curculigoside E (1) and orchioside D (2), were isolated and characterized from the rootstock of Curculigo orchioides collected in the Nawalparasi District (Nepal). The structures of the new isolated compounds were elucidated by means of spectroscopic methods such as 1D, 2D NMR and MS. PMID:19285123

Dall'Acqua, Stefano; Shrestha, Bharat Babu; Comai, Stefano; Innocenti, Gabbriella; Gewali, Mohan Bikram; Jha, Pramod Kumar

2009-03-11

39

Oleanane and ursane glycosides from Schefflera octophylla.  

PubMed

Twelve triterpene glycosides were isolated from the bark of Schefflera octophylla of Vietnamese origin. Three of them were identified as asiaticoside, cauloside D and 3 alpha-hydroxyurs-12-ene-23,28-dioic acid 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside. The structures of nine new glycosides were elucidated by chemical and spectroscopic evidence. Including the known compounds, the 12 glycosides consisted of six pairs of corresponding ursene and oleanene glycosides and all of them had the same triose moiety at the C-28 position. The names scheffurosides A-F and scheffoleosides B-F were proposed for corresponding pairs of ursene and oleanene glycosides, respectively. PMID:7765658

Maeda, C; Ohtani, K; Kasai, R; Yamasaki, K; Nguyen, M D; Nguyen, T N; Nguyen, K Q

1994-11-01

40

Phenolic glycosides from Curculigo orchioides Gaertn.  

PubMed

Five new chlorophenolic glucosides, curculigine E (1), curculigine F (2), curculigine G (3), curculigine H (5), curculigine I (6) and one new phenolic glycoside, orcinoside H (4), together with eight known phenolic glycosides (7-14) were isolated from the Curculigo orchioides Gaertn. Their structures were established by spectroscopic techniques (IR, UV, MS, 1D and 2D NMR). The isolated phenolic glycosides were evaluated for antiosteoporotic activity against MC3T3-E1 cell line using MTT assays. Compounds 1, 2, 3, and 5 showed moderate antiosteoporotic activity with the proliferation rate of 10.1-14.1%. PMID:23353659

Wang, Zhen-Hui; Huang, Jian; Ma, Xiao-Ci; Li, Guo-Yu; Ma, Yue-Ping; Li, Ning; Wang, Jin-Hui

2013-01-23

41

A new furostanol glycoside from Tribulus terrestris.  

PubMed

Besides two known glycosides, a new furostanol glycoside was isolated from the Fruits of Tribulus terrestris L. The structure of the new furostanol glycoside was established as 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furostane-20(22)-en-12-one-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside (1) on the basis of 1D and 2D-NMR techniques, including COSY, HMBC, and HMQC correlations. PMID:20335931

Xu, Yajuan; Liu, Yonghong; Xu, Tunhai; Xie, Shengxu; Si, Yunshan; Liu, Yue; Zhou, Haiou; Liu, Tonghua; Xu, Dongming

2010-01-27

42

Antibiofilm phenylethanoid glycosides from Penstemon centranthifolius.  

PubMed

Bioassay-guided fractionation of the antibacterial ethyl acetate-ethanol (50 : 50) extract obtained from the aerial parts of Penstemon centranthifolius led to the isolation of six phenylethanoid glycosides (1-6) and eleven iridoid glycosides (7-17). Their structures were determined on the basis of spectroscopic analysis and comparison with the literature. Among them, two phenylethanoid glycosides, 4'''-O-acetylverbascoside (1) and verbascoside (2), were found to show significant inhibition of the formation of bacterial biofilms by Escherichia coli UTI89. Compound 1 showed 77% biofilm inhibition at 2.5 microg/mL, and compound 2 showed 60% inhibition at 5 microg/mL. PMID:19827017

Ye, Miao; Zhao, Yun; Norman, Vanessa L; Starks, Courtney M; Rice, Stephanie M; Goering, Matt G; O'Neil-Johnson, Mark; Eldridge, Gary R; Hu, Jin-Feng

2010-05-01

43

Natural glycosides containing allopyranose from the passion fruit plant and circular dichroism of benzaldehyde cyanohydrin glycosides.  

PubMed

[structure: see text] Leaves of the edible passion fruit plant, Passiflora edulis, contain benzylic beta-D-allopyranosides 1 and 2, representatives of a rare class of natural glycosides with D-allose as the only sugar constituent. The glycoside 1 is the first known cyanogenic glycoside containing a sugar different from D-glucose attached directly to the cyanohydrin center. Asymmetric perturbation of the (1)L(b) transition of the benzene chromophore was shown to be useful for determination of absolute configuration of the cyanohydrin center of aromatic cyanogenic glycosides. PMID:11440577

Christensen, J; Jaroszewski, J W

2001-07-12

44

A new phenolic glycoside from prunella vulgaris.  

PubMed

A new phenolic glycoside was isolated from the spikes of Prunella vulgaris. Its structure was elucidated as gentisic acid 5-O-beta-D-(6'-salicylyl)-glucopyranoside by spectroscopic evidence and chemical analysis. PMID:21800544

Gu, Xiao-jie; Li, You-bin; Mu, Jun; Zhang, Yi

2011-05-01

45

Antioxidant potential of hydroxycinnamic acid glycoside esters.  

PubMed

Hydroxycinnamic acids are natural antioxidants found in fruits, vegetables, and cereals. In this study, the antioxidant activity of various types of hydroxycinnamoyl glycoside esters that mimic the structure of polymeric carbohydrates was studied in different model systems prone to oxidation, namely, liposomes and emulsions. In addition, radical scavenging activity against the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was tested. It was found that the esterification in the primary hydroxyl group of the glycoside resulted in the improved radical scavenging activity of both sinapoyl and feruloyl glycosides compared to conjugation to the secondary hydroxyl group. Increased activity was also observed, particularly in the case of feruloyl glucosides in inhibiting the oxidation of liposomes emulsions. The results showed that sinapic and ferulic acid glycoside esters were as effective or more efficient antioxidants than their free forms. In conclusion, the strength of their antioxidant effect depends on the nature of conjugation. PMID:18494493

Kylli, Petri; Nousiainen, Paula; Biely, Peter; Sipilä, Jussi; Tenkanen, Maija; Heinonen, Marina

2008-05-22

46

Engineering of cellobiose phosphorylase for glycoside synthesis.  

PubMed

Disaccharide phosphorylases are increasingly applied for glycoside synthesis, since they are very regiospecific and use cheap and easy to obtain donor substrates. A promising enzyme is cellobiose phosphorylase (CP), which was discovered more than 50 years ago. Many other bacterial CP enzymes have since then been characterized, cloned and applied for glycoside synthesis. However, the general application of wild-type CP for glycoside synthesis is hampered by its relatively narrow substrate specificity. Recently we have taken some successful efforts to broaden the substrate specificity of Cellulomonas uda CP by directed evolution and protein engineering. This review will give an overview of the obtained results and address the applicability of the engineered CP enzymes for glycoside synthesis. CP is the first example of an extensively engineered disaccharide phosphorylase, and may provide valuable information for protein engineering of other phosphorylase enzymes. PMID:21803082

de Groeve, Manu R M; Desmet, Tom; Soetaert, Wim

2011-07-20

47

Three new glycosides from Hylocereus undatus.  

PubMed

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. PMID:21751841

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

48

Two flavonol glycosides from Vancouveria hexandra.  

PubMed

In addition to two known glycosides, ikarisoside F and epimedin A, two new glycosides of a flavonol with a gamma, gamma-dimethylallyl group were isolated from the underground and the aerial parts of Vancouveria hexandra. The structures were determined to be des-O-methylanhydroicaritin 3,7-diglucoside and anhydroicaritin 3-glucosyl (1----3)rhamnoside-7-glucoside by means of spectral analysis. PMID:1367883

Mizuno, M; Kanie, Y; Iinuma, M; Tanaka, T; Lang, F A

1992-01-01

49

Documentation of reticulate evolution in peonies (Paeonia) using internal transcribed spacer sequences of nuclear ribosomal DNA: implications for biogeography and concerted evolution.  

PubMed

The internal transcribed spacers (ITS) of nuclear ribosomal DNA of 33 species of genus Paeonia (Paeoniaceae) were sequenced. In section Paeonia, different patterns of nucleotide additivity were detected in 14 diploid and tetraploid species at sites that are variable in the other 12 species of the section, suggesting that reticulate evolution has occurred. Phylogenetic relationships of species that do not show additivity, and thus ostensibly were not derived through hybridization, were reconstructed by parsimony analysis. The taxa presumably derived through reticulate evolution were then added to the phylogenetic tree according to additivity from putative parents. The study provides an example of successfully using ITS sequences to reconstruct reticulate evolution in plants and further demonstrates that the sequence data could be highly informative and accurate for detecting hybridization. Maintenance of parental sequences in the species of hybrid origin is likely due to slowing of concerted evolution caused by the long generation time of peonies. The partial and uneven homogenization of parental sequences displayed in nine species of putative hybrid origin may have resulted from gradients of gene conversion. The documented hybridizations may have occurred since the Pleistocene glaciations. The species of hybrid origin and their putative parents are now distantly allopatric. Reconstruction of reticulate evolution with sequence data, therefore, provides gene records for distributional histories of some of the parental species. PMID:7624325

Sang, T; Crawford, D J; Stuessy, T F

1995-07-18

50

Investigations of Mustard Oil Glycosides. IV. Phenyl-Thiourethane-d-Glycoside.  

National Technical Information Service (NTIS)

Particular interest is offered by the decomposition to which phenyl-thio-urethane-d-glycoside is subjected by the influence of water and acids. It assumes here, as it does in respect to its stability, a median position between thiorethane-glycosides synth...

W. Schneider D. Clibben

1968-01-01

51

Cycloartane Glycosides from Sutherlandia frutescens  

PubMed Central

Four new cycloartane glycosides, sutherlandiosides A–D (1–4), were isolated from the South African folk medicine Sutherlandia frutescens and their structures established by spectroscopic methods and X-ray crystallography as 1S,3R,24S,25-tetrahydroxy-7S,10S-epoxy-9,10-seco-9,19-cyclolanost-9(11)-ene 25-O-?-d-glucopyranoside (1), 3R,7S,24S,25-tetrahydroxycycloartan-1-one 25-O-?-d-glucopyranoside (2), 3R,24S,25-trihydroxycycloartane-1,11-dione 25-O-?-d-glucopyranoside (3), and 7S,24S,25-trihydroxycycloart-2-en-1-one 25-O-?-d-glucoyranoside (4). Compound 1 represents the first secocycloartane skeleton possessing a 7,10-oxygen bridge. Compounds 2–4 are also the first examples of naturally occurring cycloartanes with a C-1 ketone functionality. Biosynthetic considerations and chemical evidence suggest that the presence of the C-1 ketone in 2 may facilitate the ring opening of the strained cyclopropane system.

Fu, Xiang; Li, Xing-Cong; Smillie, Troy J.; Carvalho, Paulo; Mabusela, Wilfred; Syce, James; Johnson, Quinton; Folk, William; Avery, Mitchell A.; Khan, Ikhlas A.

2012-01-01

52

Simultaneous analysis of cardiac glycosides in blood and urine by thermoresponsive LC-MS-MS  

Microsoft Academic Search

A new thermoresponsive polymer separation column was applied to simultaneous analysis of four cardiac glycosides (CGs) being\\u000a widely used for the treatment of arrhythmias and heart failure in human blood and urine. This column is composed of an N-isopropylacrylamide polymer, the surface of which undergoes a reversible alteration from hydrophilic to hydrophobic by changing\\u000a temperature. The chromatographic separation and retention

Sanae Kanno; Kanako Watanabe; Itaru Yamagishi; Seishiro Hirano; Kayoko Minakata; Kunio Gonmori; Osamu Suzuki

2011-01-01

53

New steroidal glycosides from rhizomes of Clintonia udensis.  

PubMed

A total of 10 steroidal glycosides, together with three new spirostanol glycosides (6-8), a new furostanol glycoside (9), and a new cholestane glycoside (10), were isolated from the rhizomes of Clintonia udensis (Liliaceae). The structures of the new compounds were determined on the basis of extensive spectroscopic analyses, including 2-D nuclear magnetic resonance (NMR) data, and of hydrolytic cleavage followed by chromatographic or spectroscopic analyses. The isolated glycosides were evaluated for their cytotoxic activity against HL-60 leukemia cells. Spirostanol glycosides 1 and 2, and furostanol glycoside 4 showed cytotoxic activity with IC(50) values of 3.2+/-0.02, 2.2+/-0.12, and 2.2+/-0.06 microg/ml, respectively. Neither the spirostanol and furostanol saponins with a hydroxy group at C-1 (6 and 9) and C-12 (7 and 8) nor cholestane glycosides (5 and 10) exhibited apparent cytotoxic activity at a sample concentration of 10 microg/ml. PMID:18603808

Matsuo, Yukiko; Watanabe, Kazuki; Mimaki, Yoshihiro

2008-07-07

54

Phenylethanoid and iridoid glycosides from Veronica persica.  

PubMed

A new phenylethanoid glycoside, persicoside (1) and three known phenylethanoid glycosides, acteoside (2), isoacteoside (3) and lavandulifolioside (4) were isolated from the aerial parts of Veronica persica. On the basis of spectral analyses, the structure of the new compound was elucidated to be 3,4-dihydroxy-beta-phenylethoxy-O-[beta-D-glucopyranosyl-(1-->2)]-[beta-D-glucopyranosyl-(1-->3)]-4-O-caffeoyl-beta-D-glucopyranoside. Persicoside (1) and acteoside (2) exhibited radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Beside phenylethanoid glycosides, a hexitol, dulcitol (5) and seven known iridoid glucosides, aucubin (6), veronicoside (7), amphicoside (8), 6-O-veratroyl-catalpol (9), catalposide (10), verproside (11) and verminoside (12) were isolated. PMID:12045353

Harput, U Sebnem; Saracoglu, Iclal; Inoue, Makoto; Ogihara, Yukio

2002-06-01

55

?-Type Glycosidic Bond Formation by Palladium-Catalyzed Decarboxylative Allylation.  

PubMed

Decarboxylative allylation of glycals: A ?-type glycosidic bond has been constructed in high regio- and stereoselectivity by means of a palladium-catalyzed decarboxylative O-glycosylation. Various kinds of glycals with different protecting groups have been examined for this reaction to afford a diverse set of glycosylated products, including phenolic O-glycosides, thiophenolic S-glycoside, aliphatic O-glycosides, and disaccharides with excellent ?-selectivity and reasonable to excellent yields. PMID:24108596

Xiang, Shaohua; Lu, Zhiqiang; He, Jingxi; Le Maihoang, Kim; Zeng, Jing; Liu, Xue-Wei

2013-09-17

56

Novel efficient routes to indoxyl glycosides for monitoring glycosidase activities.  

PubMed

A new efficient synthesis for broad access to indoxyl glycosides was developed. Indoxylic acid allyl ester linked to a sugar structure served as the key intermediate in this route. Selective ester cleavage and mild decarboxylation led to the corresponding indoxyl glycosides in good yields. This synthesis was applied for preparation of indoxyl glycosides of fucose, sialic acid, and 6'-sialyl lactose. PMID:23829284

Böttcher, Stephan; Hederos, Markus; Champion, Elise; Dékány, Gyula; Thiem, Joachim

2013-07-05

57

Bioactive phenylpropanoid glycosides from Tabebuia avellanedae.  

PubMed

Three novel phenylpropanoid glycosides 2, 5, 6 were isolated from water extract of Tabebuia avellanedae, together with three known phenylpropanoid glycosides 1, 3, 4. All compounds were identified on the basis of spectroscopic analysis and chemical methods and, for known compounds, by comparison with published data. All isolated compounds showed strong antioxidant activity in the DPPH assay, and compound 5 give the highest antioxidant activity among all compounds, with an IC?? of 0.12 µM. All compounds exhibited moderate inhibitory effect on cytochrome CYP3A4 enzyme. PMID:23797703

Suo, Maorong; Ohta, Tomihisa; Takano, Fumihide; Jin, Shouwen

2013-06-24

58

A novel steroidal saponin glycoside from Fagonia indica induces cell-selective apoptosis or necrosis in cancer cells.  

PubMed

Fagonia indica is a small spiny shrub of great ethnopharmacological importance in folk medicine. The aqueous decoction of aerial parts is a popular remedy against various skin lesions, including cancer. We used a biological activity-guided fractionation approach to isolate the most potent fraction of the crude extract on three cancer cell lines: MCF-7 oestrogen-dependent breast cancer, MDA-MB-468 oestrogen-independent breast cancer, and Caco-2 colon cancer cells. A series of chromatographic and spectroscopic procedures were utilised on the EtOAc fraction, which resulted in the isolation of a new steroidal saponin glycoside. The cytotoxic activity of the saponin glycoside was determined in cancer cells using the MTT and neutral red uptake assays. After 24h treatment, the observed IC(50) values of the saponin glycoside were 12.5 ?M on MDA-MB-468 and Caco-2 cells, but 100 ?M on MCF-7 cells. Several lines of evidence: PARP cleavage, caspase-3 cleavage, DNA ladder assays, and reversal of growth inhibition with the pan-caspase inhibitor Z-VAD-fmk, suggested stimulation of apoptosis in MDA-MB-468 and Caco-2 cells, but not in MCF-7 cells, which do not express caspase-3. The haemolytic activity of the saponin glycoside was confirmed in sheep red blood cells, with cell lysis observed at >100 ?M, suggesting that, at this concentration, the saponin glycoside caused necrosis through cell lysis in MCF-7 cells. Using the DNA ladder assay, the saponin glycoside (12.5 ?M) was not toxic to HUVEC (human umbilical vein endothelial cells) or U937 cells, indicating some selectivity between malignant and normal cells. We conclude that the steroidal saponin glycoside isolated from F. indica is able to induce apoptosis or necrosis in cancer cells depending on the cell type. PMID:22800968

Waheed, Abdul; Barker, James; Barton, Stephen J; Owen, Caroline P; Ahmed, Sabbir; Carew, Mark A

2012-07-16

59

Bacopasaponin DA pseudojujubogenin glycoside from Bacopa monniera  

Microsoft Academic Search

A new dammarane-type pseudojujubogenin glycoside, bacopasaponin D, has been isolated from the reputed Indian medicinal plant Bacopa monniera and defined as 3-O-[?-l-arabinofuranosyl(I?2)?-d-glucopyranosyl]pseudojujubogenin by spectroscopic methods and some chemical transformations. The 13C signals of the saponin were assigned by DEPT, 1H?1H COSY and HSQC techniques.

Saraswati Garai; Shashi B. Mahato; Kazuhiro Ohtani; Kazuo Yamasaki

1996-01-01

60

Chlorination Diversifies Cimicifuga racemosa Triterpene Glycosides  

PubMed Central

Extracts from roots and rhizomes of black cohosh (Cimicifuga racemosa) are widely used as dietary supplements to alleviate menopausal symptoms. State-of-the-art QC measures involve phytochemical fingerprinting of the triterpene glycosides for species identification and chemical standardization by HPLC. In the course of developing materials and methods for standardization procedures, the major C. racemosa triterpene glycoside (1) was isolated ans initially thought to be cimicifugoside (2). Detailed HR-LC-MS and 1/2D NMR analysis of 1 and 2 unambiguously revealed that 1 is its chlorine-containing derivative of 2, namely 25-chlorodeoxycimigenol-3-O-?-D-xyloside. Accordingly, HPLC profiles of black cohosh preparations require revision of the assignments of the chlorinated (1) and non-chlorinated (2) pair. Besides explaining the substantial shift in polarity (?tR[RP-18] ca 20 min), 25-deoxychlorination opens a new pathway of structural diversification in triterpene glycosides chemistry. As chemical conversion of 2 into 1 could be demonstrated, deoxychlorination may be interpreted as artifact formation. Simultaneously, however, it is a potentially significant pathway for the gastric in vivo conversion (“nature's pro drug”) of the relatively polar triterpene glycosides into significantly less polar chlorinated derivatives with altered pharmacological properties.

Chen, Shao-Nong; Lankin, David C.; Nikolic, Dejan; Fabricant, Daniel S.; Lu, Zhi-Zhen; Ramirez, Benjamin; van Breemen, Richard B.; Fong, Harry H. S.; Farnsworth, Norman R.; Pauli, Guido F.

2008-01-01

61

A new withanolide glycoside from physalis peruviana  

PubMed

A new withanolide glycoside, 17beta-hydroxy-14, 20-epoxy-1-oxo-[22R]-3beta-[O-beta-D-glucopyranosyl]-witha-5, 24-dienolide (1), has been isolated from the whole plant of Physalis peruviana. Its identity was determined using a combination of spectroscopic data including 2D NMR techniques and chemical transformations. PMID:10096867

Ahmad; Malik; Afza; Yasmin

1999-03-01

62

Two new triterpenoid glycosides from Curculigo orchioides.  

PubMed

Two new cycloartane triterpenoid glycosides, named curculigosaponin N and curculigosaponin O, were isolated from rhizomes of Curculigo orchioides Gaertn. Their structures were elucidated on the basis of comprehensive spectroscopic analysis including IR, MS, 1D, and 2D NMR (HSQC and HMBC). PMID:22316001

Zuo, Ai-Xue; Shen, Yong; Jiang, Zhi-Yong; Zhang, Xue-Mei; Zhou, Jun; Lü, Jun; Chen, Ji-Jun

2012-02-09

63

Antiproliferative steroidal glycosides from Digitalis ciliata.  

PubMed

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 IC?? values ranging from 8.3 to 20 ?M. 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 G?/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 G?/M phase of the cell cycle. PMID:22245088

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

2012-01-08

64

Chlorination diversifies Cimicifuga racemosa triterpene glycosides.  

PubMed

Extracts from the roots and rhizomes of black cohosh (Cimicifuga racemosa) are widely used as dietary supplements to alleviate menopausal symptoms. State-of-the-art quality control measures involve phytochemical fingerprinting of the triterpene glycosides for species identification and chemical standardization by HPLC. In the course of developing materials and methods for standardization procedures, the major C. racemosa triterpene glycoside (1) was isolated and initially thought to be cimicifugoside (2). Detailed HR-LC-MS and 1D and 2D NMR analysis of 1 and 2 unambiguously revealed that 1 is the chlorine-containing derivative of 2, namely, 25-chlorodeoxycimigenol-3-O-beta-d-xyloside. Accordingly, HPLC profiles of black cohosh preparations require revision of the assignments of the chlorinated (1) and nonchlorinated (2) pair. Besides explaining the substantial shift in polarity (DeltatR[RP-18] ca. 20 min), 25-deoxychlorination opens a new pathway of structural diversification in triterpene glycoside chemistry. As chemical conversion of 2 into 1 could be demonstrated, deoxychlorination may be interpreted as artifact formation. Simultaneously, however, it is a potentially significant pathway for the gastric in vivo conversion ("nature's prodrug") of the relatively polar triterpene glycosides into significantly less polar chlorinated derivatives with altered pharmacological properties. PMID:17555351

Chen, Shao-Nong; Lankin, David C; Nikolic, Dejan; Fabricant, Daniel S; Lu, Zhi-Zhen; Ramirez, Benjamin; van Breemen, Richard B; Fong, Harry H S; Farnsworth, Norman R; Pauli, Guido F

2007-06-08

65

Redox mechanism of glycosidic bond hydrolysis catalyzed by 6-phospho-alpha-glucosidase: a DFT study.  

PubMed

Glycosidic bonds are remarkably resistant to cleavage by chemical hydrolysis. Glycoside hydrolases catalyze their selective hydrolysis in oligosaccharides, polysaccharides, and glycoconjugates by following nonredox catalytic pathways or a net redox-neutral catalytic pathway using NAD(+) and divalent metal ions as cofactors. GlvA (6-phospho-alpha-glucosidase) is a glycosidase belonging to family GH4 and follows a regioselective redox-neutral mechanism of glycosidic-bond hydrolysis that favors alpha- over beta-glycosides. Its proposed catalytic mechanism can be divided into two half-reactions: the first one activates the glucopyranose ring by successively forming intermediates that are oxidized at the 3-, 2-, and 1-positions of the ring, which ultimately facilitate the heterolytic deglycosylation. The second half-reaction is essentially the reverse of the first half-reaction, beginning with the pyranose ring hydroxylation at the anomeric carbon, and it is followed by 3-reduction and regeneration of the active forms of the catalytic site and its cofactors. We investigated the NAD(+)-dependent redox mechanism of glycosidic bond hydrolysis as catalyzed by GlvA through the combined application of density functional theory and a self-consistent reaction field to a large active-site model obtained from the crystallographic structure of the enzyme, then we applied natural bond orbital and second-order perturbation analyses to monitor the electron flow and change in oxidation state on each atomic center along the reaction coordinate to rationalize the energetics and regioselectivity of this catalytic mechanism. We find that in GlvA, the redox catalytic mechanism of hydrolysis is driven by the gradual strengthening of the axial endo-anomeric component within the hexose ring along the reaction coordinate to facilitate the heterolytic dissociation of the axial C1-O bond. In addition, the combined influence of specific components of the generalized anomeric effect fully explains the regioselectivity observed in the catalytic activity of GlvA. PMID:20698522

Huang, Wenjuan; Llano, Jorge; Gauld, James W

2010-09-01

66

Reverse Transcriptase.  

National Technical Information Service (NTIS)

Contents: Purification and properties of reverse transcriptase; Biosynthesis of reverse transcriptase; Differentiation of cellular DNA polymerases from reverse transcriptase; Characterization of reverse transcriptase complexes in vivo and in vitro; Revers...

1982-01-01

67

A novel glycoside from Acanthus hirsutus (Acanthaceae).  

PubMed

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. PMID:20433073

Capanlar, Seval; Böke, Nazli; Ya?a, Ihsan; Kirmizigül, Süheyla

2010-04-01

68

?-cyclodextrin assistant flavonoid glycosides enzymatic hydrolysis  

PubMed Central

Background: The content of icaritin and genistein in herba is very low, preparation with relatively large quantities is an important issue for extensive pharmacological studies. Objective: This study focuses on preparing and enzymic hydrolysis of flavonoid glycosides /?-cyclodextrin inclusion complex to increase the hydrolysis rate. Materials and Methods: The physical property of newly prepared inclusion complex was tested by differential scanning calorimetry (DSC). The conditions of enzymatic hydrolysis were optimized for the bioconversion of flavonoid glycosides /?-cyclodextrin inclusion complex by mono-factor experimental design. The experiments are using the icariin and genistein as the model drugs. Results: The solubility of icariin and genistein were increased almost 17 times from 29.2 ?g/ml to 513.5 ?g/ml at 60°C and 28 times from 7.78 ?g/ml to 221.46 ?g/ml at 50°C, respectively, demonstrating that the inclusion complex could significantly increase the solubility of flavonoid glycosides. Under the optimal conditions, the reaction time of icariin and genistin decreased by 68% and 145%, when compared with that without ?-CD inclusion. By using this enzymatic condition, 473 mg icaritin (with the purity of 99.34%) and 567 mg genistein(with the purity of 99.46%), which was finally determined by melt point, ESI-MS, UV, IR, 1H NMR and 13C NMR, was obtained eventually by transforming the inclusion complex(contains 1.0 g substrates). Conclusion: This study can clearly indicate a new attempt to improve the speed of enzyme-hydrolysis of poorly water-soluble flavonoid glycosides and find a more superior condition which is used to prepare icaritin and genistein.

Jin, Xin; Zhang, Zhen-hai; Sun, E.; Jia, Xiao-Bin

2013-01-01

69

Antioxidant phenylpropanoid glycosides from Smilax bracteata.  

PubMed

From the ethanolic extract of Smilax bracteata, six phenylpropanoid glycosides, smilasides G-L (1-6), along with four known phenylpropanoid compounds, helonioside A, helonioside B, smilaside E, and (1-p-O-coumaroyl-6-O-feruroyl)-beta-d-fructofuranosyl-alpha-d-glucopyranoside, and fourteen known phenolic compounds were isolated. Their structures were elucidated on the basis of spectroscopic analyses. Moreover, 1-6 exhibited moderate scavenging activities against DPPH radicals. PMID:18329678

Zhang, Lijie; Liao, Chia-Ching; Huang, Hui-Chi; Shen, Ya-Ching; Yang, Li-Ming; Kuo, Yao-Haur

2008-03-10

70

Resin Glycosides from the Morning Glory Family  

Microsoft Academic Search

\\u000a Resin glycosides are part of a very extensive family of secondary metabolites known as glycolipids or lipo-oligosaccharides\\u000a and are constituents of complex resins (glycoresins) (1) unique to the morning glory family, Convolvulaceae (2). These active\\u000a principles are responsible for the drastic purgative action of all the important Convolvulaceous species used in traditional\\u000a medicine throughout the world since ancient times. Several

Rogelio Pereda-Miranda; Daniel Rosas-Ramírez; Jhon Castańeda-Gómez

2010-01-01

71

Flavonol and anthraquinone glycosides from Rhamnus formosana.  

PubMed

Two new flavonol triglycosides, and a new anthraquinone glycoside, have been isolated from the roots of Rhamnus formosana. These compounds have been characterized as rhamnazin 3-O-[alpha-L-rhamopyranosyl(1----4)-alpha-L-rhamnopyranosyl(1----6 )]-beta-D-galactopyranoside (rhamnazin 3-isorhamninoside), rhamnocitrin 3-O-isorhamninoside and 1,6,8-trihydroxy-3-methylanthraquinone 1-O-rhamnosyl(1----2)glucoside, respectively. PMID:1367798

Lin, C N; Chung, M I; Gan, K H; Lu, C M

1991-01-01

72

Physiological roles of plant glycoside hydrolases  

Microsoft Academic Search

The functions of plant glycoside hydrolases and transglycosidases have been studied using different biochemical and molecular\\u000a genetic approaches. These enzymes are involved in the metabolism of various carbohydrates containing compounds present in\\u000a the plant tissues. The structural and functional diversity of the carbohydrates implies a vast spectrum of enzymes involved\\u000a in their metabolism. Complete genome sequence of Arabidopsis and rice

Zoran Minic

2008-01-01

73

Bioprospecting metagenomics for new glycoside hydrolases.  

PubMed

To efficiently deconstruct recalcitrant plant biomass to fermentable sugars in industrial processes, biocatalysts of higher performance and lower cost are required. The genetic diversity found in the metagenomes of natural microbial biomass decay communities may harbor such enzymes. The aim of this chapter is to describe strategies, based on metagenomic approaches, for the discovery of glycoside hydrolases (GHases) from microbial biomass decay communities, especially those from unknown or never-been-cultivated microorganisms. PMID:22843397

Gilbert, Jack; Li, Luen-Luen; Taghavi, Safiyh; McCorkle, Sean M; Tringe, Susannah; van der Lelie, Daniel

2012-01-01

74

Laccase-mediated oxidation of natural glycosides  

Microsoft Academic Search

Regioselective oxidations of the primary OH's of natural glycosides (thiocolchicoside, colchicoside, amygdalin, asiaticoside, ginsenoside RE) have been performed on a preparative scale by exploiting the laccase–2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) methodology. The influence of water-miscible organic cosolvents on the stability and activity of a laccase from Trametes pubescens has been investigated. The enzyme has been covalently linked to Eupergit C250L and its performances

Lara Baratto; Andrea Candido; Mattia Marzorati; Francesca Sagui; Sergio Riva; Bruno Danieli

2006-01-01

75

Perspectives for the industrial enzymatic production of glycosides.  

PubMed

Glycosides are of commercial interest for industry in general and specifically for the pharmaceutical and food industry. Currently chemical preparation of glycosides will not meet EC food regulations, and therefore chemical preparation of glycosides is not applicable in the food industry. Thus, enzyme-catalyzed reactions are a good alternative. However, until now the low yields obtained by enzymatic methods prevent the production of glycosides on a commercial scale. Therefore, high yields should be established by a combination of optimum reaction conditions and continuous removal of the product. Unfortunately, a bioreactor for the commercial scale production of glycosides is not available. The aim of this article is to discuss the literature with respect to enzymatic production of glycosides and the design of an industrially viable bioreactor system. PMID:14524698

de Roode, B Mattheus; Franssen, Maurice C R; van der Padt, Albert; Boom, Remko M

76

Resin glycosides from the leaves and stems of Ipomoea digitata  

Microsoft Academic Search

Alkaline hydrolysis of the ether-soluble resin glycoside (jalapin) fraction of the leaves and stems of Ipomoea digitata L. (Convolvulaceae) gave six organic acids, isobutyric, (S)-2-methylbutyric, tiglic, n-decanoic, n-dodecanoic, and cinnamic acids, and two glycosidic acids, quamoclinic acid A and operculinic acid A. Further, a new genuine\\u000a resin glycoside, named digitatajalapin I, was isolated from the jalapin fraction, along with three

Masateru Ono; Hitoshi Fukuda; Hiroko Murata; Kazumoto Miyahara

2009-01-01

77

A new flavonoid glycoside from the leaf of Cephalotaxus koreana  

Microsoft Academic Search

A new flavone glycoside, apigenin 5-O-??l-rhamnopyranosyl-(1?3)-?-d-glucopyranoside (1), along with four known flavonol glycosides (2–5), were isolated from the leaf of Cephalotaxus koreana. The new glycoside 1 showed inhibitory activity in superoxide radical scavenging assay with IC50 value of 13.0 ?M, while it showed weak activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. Compounds 2?5 exhibited antioxidant activity in scavenging DPPH and

KiHwan Bae; WenYi Jin; Phuong Thien Thuong; Byung Sun Min; MinKyun Na; Young Mi Lee; Sam Sik Kang

2007-01-01

78

Steroidal glycosides from the aerial parts of Polianthes tuberosa.  

PubMed

A chemical investigation of the aerial parts of Polianthes tuberosa resulted in the isolation of a new bisdesmosidic cholestane glycoside (1) and three new spirostanol saponins (2-4), along with a known cholestane glycoside. The structures of new glycosides were determined by spectroscopic analysis, including 2D NMR spectroscopic data, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity on HL-60 human promyelocytic leukemia cells. PMID:11087596

Mimaki, Y; Yokosuka, A; Sashida, Y

2000-11-01

79

Glycosides from the Aerial Parts of Patrinia villosa.  

PubMed

An investigation of the Korean medicinal plant Patrinia villosa (THUNB.) JUSS. (Valerianaceae) led to the isolation of two new flavonoid glycosides, patrivilosides 1 (1) and 2 (2), a new iridoid glycoside, patrinovalerosidate (3), and two new saponins, patrinovilosides A (4) and B (5), along with six known compounds including three flavonoid glycosides and three iridoid glycosides. The structures of the new compounds were elucidated based on analysis of their one dimensional (1D)- and 2D-NMR spectra along with their mass spectrometric data and the results of acid hydrolysis. PMID:23800854

Lee, Joo Young; Kim, Ju Sun; Kim, Yeong Shik; Kang, Sam Sik

2013-06-21

80

Synthesis and Characterization of Glycoside-Based Trisiloxane Surfactant  

Microsoft Academic Search

The synthesis of glycoside-based trisiloxane surfactants of the general formula Me3SiOSiMeR1OSiMe3 (R1 = (CH2)3(OCH2CH2)2OR2, R2 = glycosyl) is described, and the surface activity properties of the surfactant are studied. Diethylene glycol monoallyl\\u000a ether glycoside is synthesized by reacting the diethylene glycol monoallyl ether with glucose. The glycoside-based trisiloxane\\u000a surfactant is prepared by hydrosilylation of the precursor glycoside with hydrogen-containing trisiloxane. The product is\\u000a structurally

Fu Han; Yan-hong Chen; Ya-wen Zhou; Bao-cai Xu

81

Assembly of naturally occurring glycosides, evolved tactics, and glycosylation methods.  

PubMed

Glycosylation of proteins and lipids is critical to many life processes. Secondary metabolites (or natural products), such as flavonoids, steroids, triterpenes, and antibiotics, are also frequently modified with saccharides. The resulting glycosides include diverse structures and functions, and some of them have pharmacological significance. The saccharide portions of the glycosides often have specific structural characteristics that depend on the aglycones. These molecules also form heterogeneous "glycoform" mixtures where molecules have similar glycosidic linkages but the saccharides vary in the length and type of monosaccharide unit. Thus, it is difficult to purify homogeneous glycosides in appreciable amounts from natural sources. Chemical synthesis provides a feasible access to the homogeneous glycosides and their congeners. Synthesis of a glycoside involves the synthesis of the aglycone, the saccharide, the connection of these two parts, and the overall manipulation of protecting groups. However, most synthetic efforts to date have focused on the aglycones, treating the attachment of saccharides onto the aglycones as a dispensable topic. The synthesis of the aglycone and the synthesis of the saccharide belong to two independent categories of chemistry, and different types of the aglycones and saccharides pose as specific synthetic subjects in their own disciplines. The only reaction that integrates the broad chemistry of glycoside synthesis is the glycosidic bond formation between the saccharide and the aglycone. Focusing on this glycosylation reaction in this Account, we string together our experience with the synthesis of the naturally occurring glycosides. We briefly describe the synthesis of 18 glycosides, including glycolipids, phenolic glycosides, steroid glycosides, and triterpene glycosides. Each molecule represents a prototypical structure of a family of the natural glycosides with interesting biological activities, and we emphasize the general tactics for the synthesis of these diverse structures. We provide a rationale for four tactics for the synthesis of glycosides, based on the stage at which the glycosidic bond is formed between the saccharide and the aglycone. This choice of tactic determines the success or failure of a synthesis, and the flexibility and the overall efficiency of the synthesis as well. Toward the synthesis of heterogeneous glycoform mixtures, we discuss successive and random glycosylation reactions. Finally, we have developed two new glycosylation protocols that address the challenges in the glycosylation of aglycones that are poorly nucleophilic, extremely acid labile, or extremely electrophilic. One of these new protocols takes advantage of glycosyl trifluoroacetimidate donors, and a second protocol uses gold(I)-catalyzed glycosylation with glycosyl ortho-alkynylbenzoate donors. PMID:22493991

Yu, Biao; Sun, Jiansong; Yang, Xiaoyu

2012-04-11

82

Plant and microbial glycoside hydrolases: Volatile release from glycosidic aroma precursors  

Microsoft Academic Search

Following a brief look at the structure and occurrence of glycosidic flavour precursors in plants and fruits, attention is given to mechanisms of enzymatic hydrolysis, the properties of relevant glycosidases, as well as endogenous and exogenous glycosidases affecting flavour release in plants, in fruit juice processing and in winemaking. The constraints for technological applications and future prospects are discussed.

Jean-Emmanuel Sarry; Ziya Günata

2004-01-01

83

Flavonoid glycosides and methylinositol from Ebenus haussknechtii.  

PubMed

Two flavonoid glycosides (compounds 1 and 3) of which one is reported for the first time and a methylinositol (compound 2) were isolated from the aerial parts of Ebenus haussknechtii (Leguminosae). The structures were established as quercetin-7-O-[alpha-L-rhamnopyranosyl(1 --> 6)-beta-D-galactopyranoside] (1), morin-3-O-[4-[5-(4-hydroxyphenyl)pentanoyl]-alpha-L-rhamnopyranosyl(1 --> 6)-beta-D-galactopyranosyl]-7-4'-di-O-methyleter (3), and methylinositol (2) on the basis of chemical and spectroscopic means. The antimicrobial activities of the extracts have also been examined. PMID:17050182

Uyar, Zafer; Böke, Nazli; Türkay, Elçin; Koz, Omer; Ya?a, Ihsan; Kirmizigül, Süheyla

2006-09-01

84

Additional minor diterpene glycosides from Stevia rebaudiana.  

PubMed

From the commercial extract of the leaves of Stevia rebaudiana, two additional new diterpenoid glycosides were isolated and their structures were characterized as 13-[(2-O-beta-glucopyranosyl-3-O-beta-D-xylopyranosyl-beta-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid beta-D-glucopyranosyl ester (1) and 13-[(2-O-beta-D-xylopyranosyl-beta-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid beta-D-glucopyranosyl ester (2) on the basis of extensive spectral data (NMR and MS) and chemical studies. PMID:21922898

Chaturvedula, Venkata Sai Prakash; Prakash, Indra

2011-08-01

85

Flavonoid and phenolic glycosides from Salvia officinalis.  

PubMed

Two novel phenolic glycosides cis-p-coumaric acid 4-O-(2'-O-beta-D-apiofuranosyl)-beta-D-glucopyranoside and trans-p-coumaric acid 4-O-(2'-O-beta-D-apiofuranosyl)-beta-D-glucopyranoside were isolated and identified from Salvia officinalis together with 4-hydroxyacetophenone 4-O-(6'-O-beta-D-apiofuranosyl)-beta-D-glucopyranoside, luteolin 7-O-beta-D-glucoside, 7- and 3'-O-beta-D-glucuronide, 6-hydroxyluteolin 7-O-beta-D-glucoside and 7-O-glucuronide, and 6,8-di-C-beta-D-glucosylapigenin (vicenin-2). The luteolin glucuronides and vicenin-2 were identified as new sage constituents. PMID:11142853

Lu, Y; Foo, L Y

2000-10-01

86

ent-Kaurane Glycosides from Tricalysia okelensis  

PubMed Central

Tricalysiosides V and W, two new ent-kaurane glycosides with an acylated disaccharide moiety at the C-3 position, were isolated from the roots of Tricalysia okelensis and their structures established by spectroscopic and chemical methods as ent-kauran-3?,16?,17-triol-19-al 3-O-[5-O-vanilloyl-?-D-apiopyranosyl(1?6)]-?-D-glucopyranoside (1) and ent-kauran-3?,16?,17-triol-19-al 3-O-[5-O-E-sinapoyl-?-D-apiopyranosyl(1?6)]-?-D-glucopyranoside (2).

Xu, Wen-Hui; Jacob, Melissa R.; Agarwal, Ameeta K.; Clark, Alice M.; Liang, Zong-Suo; Li, Xing-Cong

2013-01-01

87

Glycosidic constituents from in vitro Anoectochilus formosanus.  

PubMed

The glycosidic constituents of whole plants of Anoectochilus formosanus propagated by tissue culture were investigated. A new compound, 2-(beta-D-glucopyranosyloxymethyl)-5-hydroxymethylfuran, along with the known compounds, 3-(R)-3-beta-D-glucopyranosyloxybutanolide (kinsenoside), 3-(R)-3-beta-D-glucopyranosyloxy-4-hydroxybutanoic acid, 1-O-isopropyl-beta-D-glucopyranoside, (R)-(+)-3,4-dihydroxy-butanoic acid y-lactone, 4-(beta-D-glucopyranosyloxy)benzyl alcohol, (6R,9S)-9-hydroxy-megastigma-4,7-dien-3-one-9-O-beta-glucopy ranoside, and corchoionoside C were isolated. PMID:11086921

Du, X M; Sun, N Y; Irino, N; Shoyama, Y

2000-11-01

88

A new spermatostatic glycoside from the soft coral Sinularia crispa.  

PubMed

The steroid glycoside 1 has been isolated from the Sri Lankan soft coral Sinularia crispa. The structure has been determined by spectroscopic (1H and 13C nmr) techniques. Glycoside 1 showed spermatostatic activity on rat cauda epididymal spermatozoa. PMID:2575139

Tillekeratne, L M; Liyanage, G K; Ratnasooriya, W D; Ksebati, M B; Schmitz, F J

89

Two flavonol glycosides from the underground parts of Vancouveria hexandra.  

PubMed

Two new flavonol glycosides were isolated from the roots and rhizomes of Vancouveria hexandra. The glycosides were determined by chemical and spectral means to be anhydroicaritin 3-galactosyl(1----3) rhamnoside-7-glucoside and anhydroicaritin 3-[6-O-acetyl-galactosyl(1----3)rhamnoside]-7-glucoside. PMID:1366428

Mizuno, M; Iinuma, M; Tanaka, T; Sakakibara, N; Murata, J; Murata, H; Lang, F A

1990-01-01

90

Cycloartane glycosides from the rhizomes of Curculigo orchioides.  

PubMed

Cycloartane glycosides (1-9) were isolated from rhizomes of Curculigo orchioides (Hypoxidaceae), and this structures were determined by spectroscopic analysis and a few chemical transformations. Cytotoxic activity of glycosides (1-9) and their common aglycone (1a) against HL-60 human promyelocytic leukemia cells was also examined. PMID:20965526

Yokosuka, Akihito; Sato, Koji; Mimaki, Yoshihiro

2010-10-19

91

Acylated flavonol glycosides from leaves of Planchonia grandis.  

PubMed

Three acylated flavonol glycosides have been identified from leaves of Planchonia grandis Ridley. They possess kaempferol as aglycone and two triglycosidic chains substituting hydroxyl groups at the 3- and 7-positions. The first glycosidic unit of each chain is esterified by a cis or trans p-coumaric acid. Structural elucidation was achieved by means of UV, NMR and mass spectrometry. PMID:12943780

Crublet, Marie-Laure; Long, Christophe; Sévenet, Thierry; Hadi, Hamid A; Lavaud, Catherine

2003-09-01

92

Acylated flavonol glycosides from leaves of Planchonia grandis  

Microsoft Academic Search

Three acylated flavonol glycosides have been identified from leaves of Planchonia grandis Ridley. They possess kaempferol as aglycone and two triglycosidic chains substituting hydroxyl groups at the 3- and 7-positions. The first glycosidic unit of each chain is esterified by a cis or trans p-coumaric acid. Structural elucidation was achieved by means of UV, NMR and mass spectrometry.

Marie-Laure Crublet; Christophe Long; Thierry Sévenet; Hamid A Hadi; Catherine Lavaud

2003-01-01

93

Fully acetylated carbamate and hypotensive thiocarbamate glycosides from Moringa oleifera  

Microsoft Academic Search

Six new and three synthetically known glycosides have been isolated from the leaves of Moringa oleifera, employing a bioassay-directed isolation method on the ethanolic extract. Most of these compounds, bearing thiocarbamate, carbamate or nitrile groups, are fully acetylated glycosides, which are very rare in nature. Elucidation of the structures was made using chemical and spectroscopic methods, including 2D NMR techniques.

Shaheen Faizi; Bina Shaheen Siddiqui; Rubeena Saleem; Salimuzzaman Siddiqui; Khalid Aftab; Anwar-Ul-Hassan Gilani

1995-01-01

94

Glycoside hydrolases and glycosyltransferases: families and functional modules  

Microsoft Academic Search

The past year has witnessed the expected increase in the number of solved structures of glycoside hydrolases and glycosyltransferases, and their constitutive modules. These structures show that, while glycoside hydrolases display an extraordinary variety of folds, glycosyltransferases and carbohydrate-binding modules appear to belong to a much smaller number of folding families.

Yves Bourne; Bernard Henrissat

2001-01-01

95

Structural and sequence-based classification of glycoside hydrolases  

Microsoft Academic Search

The diversity of oligo- and polysaccharides provides an abundance of biological roles for these carbohydrates. The enzymes hydrolysing these compounds, the glycoside hydrolases, therefore mediate a wealth of biological functions. Glycoside hydrolases fall into a number of sequence-based families. The recent analysis of these families, coupled with the burgeoning number of 3D structures, provides a detailed insight into the structure,

Bernard Henrissat; Gideon Davies

1997-01-01

96

A method for preparing C-glycosides related to phlorizin  

Microsoft Academic Search

Johnson's Suzuki coupling protocol was employed to prepare C-glycoside analogs of phlorizin (1). In vitro biological evaluation of these C-glycosides indicated the anomeric oxygen is important to the SGLT inhibitory activity of phlorizin (1) and related agents.

J. T Link; Bryan K Sorensen

2000-01-01

97

Antiproliferative Cardiac Glycosides from the Latex of Antiaris toxicaria.  

PubMed

Phytochemical investigation of the latex of Antiaris toxicaria resulted in the isolation of 15 new [antiarosides J-X (1-15)] and 17 known cardiac glycosides. The effects of the cardiac glycosides on apoptosis and the expression of orphan nuclear receptor Nur77 were examined in human NIH-H460 lung cancer cells. Several of the cardiac glycosides induced apoptosis in lung cancer cells, which was accompanied by induction of Nur77 protein expression. Treatment of cancer cells with the cardiac glycosides resulted in translocation of the Nur77 protein from the nucleus to the cytoplasm and subsequent targeting to mitochondria. The results show that the cardiac glycosides exert their apoptotic effect through the Nur77-dependent apoptotic pathway. PMID:24033101

Liu, Qian; Tang, Jin-Shan; Hu, Meng-Jie; Liu, Jie; Chen, Hai-Feng; Gao, Hao; Wang, Guang-Hui; Li, Shun-Lin; Hao, Xiao-Jiang; Zhang, Xiao-Kun; Yao, Xin-Sheng

2013-09-13

98

Purification of glycoside hydrolases from Bacteroides fragilis.  

PubMed Central

Six glycoside hydrolases in the culture medium of Bacteroides fragilis--alpha-glucosidase, beta-glucosidase, alpha-galactosidase, beta-galactosidase, beta-N-acetylglucosaminidase, and alpha-L-fucosidase-were systematically purified by ammonium sulfate precipitation, gel filtration chromatography, and density gradient isoelectric focusing. The isoelectric focusing resolved the glycosidases into distinct, well-separated fractions and revealed three differently charged forms of beta-N-acetylglucosaminidase and of alpha-L-fucosidase. Furthermore, alpha-glucosidase and beta-N-acetylglucosaminidase were shown to possess dual affinities for the respective galactoside substrates, and beta-galactosidase also hydrolyzed beta-D-fucoside. alpha-Glucosidase was purified to homogeneity, as indicated by a thin-layer isoelectric focusing zymogram technique. The glycosidases, with exception of beta-glucosidase and the acid alpha-L-fucosidase, were each separated from other glycosidic activities to 99%. The molecular weights varied between 58,000 and 125,000. The pH optima ranged from 4.8 to 6.9. Images

Berg, J O; Lindqvist, L; Nord, C E

1980-01-01

99

[Cardiac glycosides: From ancient history through Withering's foxglove to endogeneous cardiac glycosides].  

PubMed

For centuries, drugs that increase the power of contraction of the failing heart have been used for the treatment of congestive heart failure (dropsy). The cardiac effect is due to the content of cardiac glycosides. Squill or sea onion, Urginea (Scilla) maritima, a seashore plant, was known by the ancient Romans and Syrians and possibly also by the ancient Egyptians. Squills were used erratically, but some prescriptions indicate that they may have been used for the treatment of oedematous states. The toxic effect of strophanthus species was known from poisoned arrows used by the natives in Africa. Digitalis, derived form the foxglove plant, Digitalis purpurea, is mentioned in writings as early as 1250; a Welsh family, known as the Physicians of Myddvai, collected different herbs and digitalis was included in their prescriptions. However, the druge was used erratically until the 18th century, when William Withering, an English physician and botanist, published a monograph describing the clinical effects of an extract of the foxglove plant. Later, in 1785, the indication and the toxicity of digitalis were reported in his book, "An account of the Foxglove and some of its medical uses with practical remarks on dropsy, and other diseases". In Denmark, the leaves of Digitalis purpurea or Digitalis lanata were tested for cardiac glycoside activity. The standardized digitalis powder was used in tinctures, infusions, and tablets. The preparations were included in successive editions of the Danish pharmacopoeia, some of the tinctures already in 1828, i.e. before the standardization of the drug. Isolation of cardiac glycosides from digitalis, strophanthus and squill and determination of their chemical structures initiated biochemical and pharmacological studies. The scientific advances led to an understanding of cardiac muscle contractility and the Na,K pump as the cellular receptor for the inotropic action of digitalis. Examination of putative endogenous ligands to the receptor revealed some endogenous cardiac glycosides of similar or identical structures as those found in digitalis, strophanthus and squill. Increased concentrations of these glycosides are found in patients with heart failure. Further investigations are needed to determine whether the secretion of glycosides might be a physiologic response to a diminished cardiac output. PMID:15685783

Norn, Svend; Kruse, Poul R

2004-01-01

100

Determination of phenylethanoid glycosides and iridoid glycosides from therapeutically used Plantago species by CE-MEKC.  

PubMed

CE methods are valuable tools for medicinal plant quality management, screening, and analysis. Therefore, the aim of the current study was to optimize and validate a CE-MEKC method for simultaneous quantification of four chief bioactive metabolites from Plantago species. The two most important secondary metabolite groups were aimed to be separated. Different electrolyte and surfactant types were tested. Surfactant concentration, BGE pH, electrolyte concentration, and buffering capacity were optimized. The final BGE consisted of 15 mM sodium tetraborate, 20 mM TAPS, and 250 mM DOC at pH 8.50. Acceptable precision, good stability, and accuracy were achieved, with high resolution for phenylethanoid glycosides. Analytes were separated within 20 min. The method was shown to be suitable for the quantification of the iridoid glycosides aucubin and catalpol, and the phenylethanoid glycosides acteoside (verbascoside) and plantamajoside from water extracts of different samples. The method was shown to be applicable to leaf extracts of Plantago lanceolata, Plantago major, and Plantago asiatica, the main species with therapeutic applications, and a biotechnological product, plant tissue cultures (calli) of P. lanceolata. Baseline separation of the main constituents from minor peaks was achieved, regardless of the matrix type. PMID:23784714

Gonda, Sándor; Nguyen, Nhat Minh; Batta, Gyula; Gyémánt, Gyöngyi; Máthé, Csaba; Vasas, Gábor

2013-07-29

101

Reverse Osmosis  

NSDL National Science Digital Library

Reverse Osmosis: In reverse osmosis, the idea is to use the membrane to act like an extremely fine filter to create drinkable water from salty (or otherwise contaminated) water. A complete explanation is here along with helpful diagrams.

2008-09-22

102

Steroidal glycosides from Furcraea foetida and their cytotoxic activity.  

PubMed

Two new spirostanol glycosides (1, 2) and a new furostanol glycoside (3), together with nine known steroidal glycosides (4-12) were isolated from the leaves of Furcraea foetida (Agavaceae). The structures of the new compounds were determined by spectroscopic analysis and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activities against HL-60 human leukemia cells, A549 human lung adenocarcinoma cells, HSC-2 human oral squamous carcinoma cells, and HSC-4 human oral squamous carcinoma cells. PMID:19801882

Yokosuka, Akihito; Sano, Tomoe; Hashimoto, Ken; Sakagami, Hiroshi; Mimaki, Yoshihiro

2009-10-01

103

Five new flavonoid glycosides from Nervilia fordii.  

PubMed

Five new flavonoid glycosides, namely nervilifordins F-J (1-5), were isolated from the 60% EtOH extract of the aerial parts of Nervilia fordii, along with three first isolated flavonoids (7, 8, and 13) and five known flavonoids (6, 9-12). The structures of new compounds were elucidated on the basis of 1D and 2D NMR and MS studies. Their anti-inflammatory activities were tested by measuring their inhibitory effects on nitric oxide production in lipopolysaccharide-activated RAW264.7 macrophages. Compounds 2 and 5 showed interesting inhibition effects with their EC50 values of 15.15 ?M and 14.80 ?M, respectively. PMID:23659497

Qiu, Li; Jiao, Yang; Xie, Ji-Zhao; Huang, Gui-Kun; Qiu, Shao-Ling; Miao, Jian-Hua; Yao, Xin-Sheng

2013-05-10

104

The Use of Digitalis Glycosides in the Dog and Cat  

PubMed Central

The author reviews the pharmacological properties of digitalis glycosides and their clinical use in the control of congestive heart failure in the dog and cat. Methods of digitalization, dosage for each drug, toxic effects and drug interactions are described.

Difruscia, R.

1984-01-01

105

Resin glycosides from the aerial parts of Operculina turpethum.  

PubMed

Three glycosidic acids, turpethic acids A-C, and two intact resin glycosides, turpethosides A and B, all having a common pentasaccharide moiety and 12-hydroxy fatty acid aglycones of different chain lengths, were obtained from the aerial parts of Operculina turpethum. Their structures were elucidated by spectroscopic analyses and chemical correlations. The aglycones were characterized as 12-hydroxypentadecanoic acid in two compounds, 12-hydroxyhexadecanoic acid in two other components, and 12-hydroxyheptadecanoic acid in the fifth compound, which were all confirmed by synthesis. The absolute configurations of these aglycones were all established as S by Mosher's method. These compounds represent the first examples of resin glycosides with a monohydroxylated 12-hydroxy fatty acid as an aglycone, and one compound is the first described resin glycoside having a hydroxylated C(17) fatty acid as its aglycone. PMID:22717506

Ding, Wenbing; Jiang, Zi-Hua; Wu, Ping; Xu, Liangxiong; Wei, Xiaoyi

2012-06-18

106

Anti-neutrophilic inflammatory steroidal glycosides from Solanum torvum.  

PubMed

Torvpregnanosides A and B, two pregnane glycosides, and torvoside Q, a 23-keto-spirostanol glycoside, along with twelve known steroidal saponins were isolated from aerial parts of Solanum torvum. Of the latter, four of the 23-hydroxy-spirostanol glycosides, and, a yamogenin glycoside, were in this plant discovered. All structures were identified from spectroscopic data, and all the compounds were tested for in vitro anti-neutrophilic inflammatory activity. Two compounds showed selective inhibition against elastase release and superoxide anion generation, respectively, by human neutrophils with IC50 values of 5.66 and 3.59?M, while two others inhibited both inflammatory mediators with IC50 values of 0.66-3.49?M. Structure-activity relationships are discussed. PMID:23838628

Lee, Chia-Lin; Hwang, Tsong-Long; He, Wan-Jung; Tsai, Yi-Hong; Yen, Chiao-Ting; Yen, Hsin-Fu; Chen, Chao-Jung; Chang, Wei-Yi; Wu, Yang-Chang

2013-07-06

107

Macedonine, a non-glycosidic iridoid from Galium macedonicum  

Microsoft Academic Search

A new non-glycosidic iridoid, macedonine, was isolated from Galium macedonicum. The structure, stereochemistry and conformation were determined by spectral methods and molecular mechanics calculations. Macedonine lacks the 3,4-double bond and the C-1 substituent.

Maya Mitova; Nedjalka Handjieva; Stefan Spassov; Simeon Popov

1996-01-01

108

Two new triterpenoidal glycosides from Medicago polymorpha L.  

PubMed

Two new triterpenoid glycosides called medicago-saponins P1 (1) and P2 (2) were isolated together with five known glycosides from the aerial parts of Medicago polymorpha L. (Leguminosae). The structures of 1 and 2 were determined to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl caulophyllogenin 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside and the desglucoside of 1. PMID:8069980

Kinjo, J; Uemura, H; Nakamura, M; Nohara, T

1994-06-01

109

Three New Steroidal Glycosides from the Roots of Cynanchum stauntonii  

PubMed Central

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.

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

2013-01-01

110

Steroidal saponins and pregnane glycosides from Smilax microphylla.  

PubMed

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. PMID:23042046

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

2012-10-08

111

Two new glycosides from the florets of Carthamus tinctorius.  

PubMed

Two new glycoside compounds, named saffloquinoside C (1) and (-)-4-hydroxybenzoic acid-4-O-[6'-O-(2?-methylbutyryl)-?-D-glucopyranoside] (2), were isolated from the florets of Carthamus tinctorius. Their structures were elucidated by detailed spectroscopic means including UV, IR, HR-ESI-MS, 1D and 2D NMR, and CD data. Compound 1 was a rare quinochalcone glycoside with six five-membered dioxaspirocycle. PMID:23600648

Jiang, Jian-Shuang; Chen, Zhong; Yang, Ya-Nan; Feng, Zi-Ming; Zhang, Pei-Cheng

2013-04-22

112

Furostanol glycosides from the rhizomes of Helleborus orientalis.  

PubMed

Eight new furostanol glycosides (1-8), together with two known ones (9 and 10), have been isolated from a glycoside-enriched fraction prepared from the rhizomes of Helleborus orientalis (Ranunculaceae). The structures of 1-8 were determined on the basis of extensive spectroscopic analysis, including 2D NMR, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HSC-2 cells. PMID:20563660

Mimaki, Yoshihiro; Matsuo, Yukiko; Watanabe, Kazuki; Sakagami, Hiroshi

2010-06-19

113

Characterization and Synergistic Interactions of Fibrobacter succinogenes Glycoside Hydrolases  

Microsoft Academic Search

The objectives of this study were to characterize Fibrobacter succinogenes glycoside hydrolases from different glycoside hydrolase families and to study their synergistic interactions. The gene encoding a major endoglu- canase (endoglucanase 1) of F. succinogenes S85 was identified as cel9B from the genome sequence by reference to internal amino acid sequences of the purified native enzyme. Cel9B and two other

Meng Qi; Hyun-Sik Jun; Cecil W. Forsberg

2007-01-01

114

Antioxidant phenolic glycosides from the bark of Populus ussuriensis Kom.  

PubMed

Study on the EtOAc soluble fraction from the bark of Populus ussuriensis Kom. resulted in the isolation of three phenolic glycosides, including populoside (1), 7-O-?-coumaroylsalirepin (2) and 7-O-caffeoylsalirepin (3), among which 3 is a new compound. The structures of these compounds were elucidated on the basis of spectroscopic evidence. Phenolic glycosides 1-3 exhibited excellent antioxidant activity, evaluated in the ABTS? radical scavenging assay. PMID:19662569

Si, Chuan-Ling; Li, Shu-Ming; Liu, Zhong; Kim, Jin-Kyu; Bae, Young-Soo

2011-07-08

115

Warfarin reversal.  

PubMed

Warfarin is the most commonly used oral anticoagulant in the UK. It is associated with few side effects apart from haemorrhage. The most appropriate way to reverse the anticoagulant effect of warfarin depends on the clinical circumstances. In serious bleeding, rapid reversal is required, whereas in minor bleeding or asymptomatic over anticoagulation, a more leisurely approach is usually appropriate. This review discusses the current approaches to warfarin reversal in clinical practice. The development of a uniform approach to warfarin reversal in the Northern Region is described. PMID:15509671

Hanley, J P

2004-11-01

116

Resin Glycosides from the Morning Glory Family  

NASA Astrophysics Data System (ADS)

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.

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

117

30-normedicagenic acid glycosides from Chenopodium foliosum.  

PubMed

Two new glycosides of 30-normedicagenic acid, namely 3-O-[beta-D-glucuronopyranosyl methyl ester]-2beta,3beta-dihydroxy-30-noroleane-12,20(29)-diene-23,28-dioic acid 28-O-beta-D-glucopyranosyl ester, and 3-O-beta-D-glucopyranosyl-2beta,3beta-dihydroxy-30-noroleane- 12,20(29)-diene-23,28-dioic acid, together with the known 3-O-beta-glucopyranosyl-2beta,3beta-dihydroxy-30-noroleane-12,20(29)-diene-23 ,28-dioic acid 28-O-beta-glucopyranosyl ester, and 3-O-beta-glucuronopyranosyl-2beta,3beta-dihydroxy-30-noroleane-12,20(29)-diene-23,28-dioic acid 28-O-beta-glucopyranosyl ester were isolated from the aerial parts of Chenopodium foliosum Asch. The structures of the compounds were determined by means of spectroscopic methods (1D and 2D NMR, UV, IR) and HRMS-ESI. The compounds were tested for cytotoxicity on three leukemic cell lines (BV-173, SKW-3, HL-60). In addition, the saponins showed moderate stimulatory effects on interleukin-2 production in PHA/PMA stimulated Jurkat E6.1 cells. PMID:23285798

Nedialkov, Paraskev T; Kokanova-Nedialkova, Zlatina; Bücherl, Daniel; Momekov, Georgi; Heilmann, Jörg; Nikolov, Stefan

2012-11-01

118

Glycosidic Inhibitors of Melanogenesis from Leaves of Passiflora edulis.  

PubMed

A new flavonoid glycoside, chrysin 6-C-?-rutinoside (chrysin ?-L-rhamnopyranosyl-(1?6)-C-?-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 ?-melanocyte-stimulating hormone (?-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??M. 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 ?-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. PMID:24130028

Zhang, Jie; Koike, Ryosuke; Yamamoto, Ayako; Ukiya, Motohiko; Fukatsu, Makoto; Banno, Norihiro; Miura, Motofumi; Motohashi, Shigeyasu; Tokuda, Harukuni; Akihisa, Toshihiro

2013-10-01

119

Central nervous system depressant action of flavonoid glycosides.  

PubMed

The pharmacological effects on the central nervous system (CNS) of a range of available flavonoid glycosides were explored and compared to those of the glycosides 2S-hesperidin and linarin, recently isolated from valeriana. The glycosides 2S-neohesperidin, 2S-naringin, diosmin, gossipyn and rutin exerted a depressant action on the CNS of mice following i.p. injection, similar to that found with 2S-hesperidin and linarin. We demonstrate in this work that these behavioural actions, as measured in the hole board, thiopental induced sleeping time and locomotor activity tests, are unlikely to involve a direct action on gamma-aminobutyric acid type A (GABA(A)) receptors. The corresponding aglycones were inactive, pointing to the importance of the sugar moieties in the glycosides in their CNS depressant action following systemic administration. The pharmacological properties of the flavonoid glycosides studied here, in addition to our previous results with hesperidin and linarin, opens a promising new avenue of research in the field. PMID:16698011

Fernández, Sebastián P; Wasowski, Cristina; Loscalzo, Leonardo M; Granger, Renee E; Johnston, Graham A R; Paladini, Alejandro C; Marder, Mariel

2006-04-06

120

ISOFLAVONE CONJUGATES AND MINOR GLYCOSIDES EXTRACTED FROM PEANUT HEARTS USING HPLC-MS  

Technology Transfer Automated Retrieval System (TEKTRAN)

High performance liquid chromatography and electrospray mass spectrometry (ESI) was used to characterize isoflavone glycosidic conjugates and minor glycosides extracted from peanut meal. The selected extraction method combined the removal of isoflavones and their conjugates with an alcoholic solvent...

121

Reversible cardiomyopathy.  

PubMed

We report a case of reversible dilated cardiomyopathy, in a middle-aged male. The patient presented with severe left ventricular dysfunction and atrial fibrillation. Inspite of vigorous medical therapy there was only mild clinical improvement. Subsequently laboratory test results diagnosed it as hyperthyroidism and then specific thyrostatic treatment was added. There was a prompt clinical and hemodynamic improvement in the form of reversal of left ventricular dysfunction and achievement of sinus rhythm at the end of two weeks. PMID:17212027

Dhadke, S V; Dhadke, V N

2006-09-01

122

New anthraquinone glycosides from the roots of Morinda citrifolia.  

PubMed

Six new anthraquinone glycosides: digiferruginol-1-methylether-11-O-beta-gentiobioside (1); digiferruginol-11-O-beta-primeveroside (2); damnacanthol-11-O-beta-primeveroside (3); 1-methoxy-2-primeverosyloxymethyl-anthraquinone-3-olate (4); 1-hydroxy-2-primeverosyloxymethyl-anthraquinone-3-olate (5); and 1-hydroxy-5,6-dimethoxy-2-methyl-7-primeverosyloxyanthraquinone (6) were isolated from Morinda citrifolia (Rubiaceae) roots together with four known anthraquinone glycosides. The structures of the new compounds were established using spectral methods. For five of the new compounds, the sugar is attached via the hydroxymethyl group of the anthraquinone C-2 carbon. This type of bond is rarely found for anthraquinone glycosides isolated from natural sources. PMID:19233251

Kamiya, Kohei; Hamabe, Wakako; Tokuyama, Shogo; Satake, Toshiko

2009-02-21

123

Annotation and comparative analysis of the glycoside hydrolase genes in Brachypodium distachyon  

Microsoft Academic Search

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

Ludmila Tyler; Jennifer N Bragg; Jiajie Wu; Xiaohan Yang; Gerald A Tuskan; John P Vogel

2010-01-01

124

New anthraquinone glycosides from the roots of Morinda citrifolia  

Microsoft Academic Search

Six new anthraquinone glycosides: digiferruginol-1-methylether-11-O-?-gentiobioside (1); digiferruginol-11-O-?-primeveroside (2); damnacanthol-11-O-?-primeveroside (3); 1-methoxy-2-primeverosyloxymethyl-anthraquinone-3-olate (4); 1-hydroxy-2-primeverosyloxymethyl-anthraquinone-3-olate (5); and 1-hydroxy-5,6-dimethoxy-2-methyl-7-primeverosyloxyanthraquinone (6) were isolated from Morinda citrifolia (Rubiaceae) roots together with four known anthraquinone glycosides. The structures of the new compounds were established using spectral methods. For five of the new compounds, the sugar is attached via the hydroxymethyl group of the anthraquinone C-2 carbon.

Kohei Kamiya; Wakako Hamabe; Shogo Tokuyama; Toshiko Satake

2009-01-01

125

Caucasicosides E-M, furostanol glycosides from Helleborus caucasicus.  

PubMed

Nine furostanol glycosides, namely caucasicosides E-M, were isolated from the MeOH extract of the leaves of Helleborus caucasicus, along with 11 known compounds including nine furostanol glycosides, a bufadienolide and an ecdysteroid. Their structures were established by the extensive use of 1D and 2D NMR experiments along with ESIMS(n) analyses. The steroidal composition of leaves of H. caucasicus shows as particular feature the occurrence of steroidal compounds belonging to the 5? series, unusual for Helleborus species, and in particular, caucasicosides F-H are based on a 5?-polyhydroxylated steroidal aglycon never reported before. PMID:21893324

Muzashvili, Tamar; Perrone, Angela; Napolitano, Assunta; Kemertelidze, Ether; Pizza, Cosimo; Piacente, Sonia

2011-09-03

126

Three new steroid glycosides from the starfish Asterina pectinifera.  

PubMed

Three new steroid glycosides, pectiniosides H-J (1-3), were isolated along with three known compounds (4-6) including a steroid glycoside and two polyhydroxysteroids, from the alcoholic extract of the starfish Asterina pectinifera. The structures of 1-3 were determined by extensive NMR and HR-ESI-MS experiments. Compounds 1-4 did not show cytostatic activity on HL-60 cells below 100 ?M, while compounds 5-6 showed moderate cytostatic activity, with IG50 values of 80.3 and 40.5 ?M, respectively. PMID:23339622

Li, Zhanqiang; Chen, Gang; Lu, Xuan; Wang, Haifeng; Feng, Baomin; Pei, Yuehu

2013-01-23

127

Phenylethanoid and flavone glycosides from Ruellia tuberosa L.  

PubMed

A new phenylethanoid glycoside, isocassifolioside (8), and two new flavone glycosides, hispidulin 7-O-?-L-rhamnopyranosyl-(1'? ? 2?)-O-?-D-glucuronopyranoside (11) and pectolinaringenin 7-O-?-L-rhamnopyranosyl-(1'? ? 2?)-O-?-D-glucuronopyranoside (12) were isolated from the aerial portions of Ruellia tuberosa L., together with verbascoside (1), isoverbascoside (2), nuomioside (3), isonuomioside (4), forsythoside B (5), paucifloside (6), cassifolioside (7), hispidulin 7-O-?-D-glucuronopyranoside (9) and comanthoside B (10). The structure elucidations were based on analyses of chemical and spectroscopic data including 1D- and 2D-NMR. The isolated compounds 1-12 exhibited radical scavenging activity using ORAC assay. PMID:22447282

Phakeovilay, Chiobouaphong; Disadee, Wannaporn; Sahakitpichan, Poolsak; Sitthimonchai, Somkit; Kittakoop, Prasat; Ruchirawat, Somsak; Kanchanapoom, Tripetch

2012-03-25

128

A new stilbene glycoside from the n -butanol fraction of Veratrum dahuricum  

Microsoft Academic Search

A new stilbene glycoside, 5-methylresveratrol-3,4?-O-?-D-diglucopyranoside (1), was isolated from the n-butanol fraction of the rhizomes of Veratrum dahuricum, together with five known stilbenoids: resveratrol-3-O-?-D-glycoside (2), 4?-methylresveratrol-3-O-?-D-glycoside (3), oxyresveratrol-4?-O-?-D-glycoside (4), oxyresveratrol-3-O-?-D-glycoside (5), and oxyresveratrol-3,4?-O-?-D-diglycoside (6), and found for the first time in the investigated plant. The structures of six isolates were identified on the basis of\\u000a 1D and 2D NMR data.

Li-Min Dai; Jian Tang; Hui-Liang Li; Yun-Heng Shen; Cai-Yun Peng; Wei-Dong Zhang

2009-01-01

129

Use of glycoside hydrolase family 8 xylanases in baking  

Microsoft Academic Search

Xylanases have long been used in the baking industry for improving dough stability and flexibility and for increasing bread volume and crumb structure. Only xylanases from glycoside hydrolase families 10 and 11 appear to have been tested in this application and only those from the latter family have as yet found application. Interestingly, enzymes with a putative xylanase activity are

Tony Collins; Anne Hoyoux; Agnčs Dutron; Jacques Georis; Bernard Genot; Thierry Dauvrin; Filip Arnaut; Charles Gerday; Georges Feller

2006-01-01

130

Structural revision of two flavanonol glycosides from Smilax glabra.  

PubMed

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. PMID:19199231

Zhou, Xiang; Xu, Qiang; Li, Jian-Xin; Chen, Ting

2009-02-06

131

Cytotoxic phenylpropanoid glycosides from Fagopyrum tataricum (L.) Gaertn  

Microsoft Academic Search

Fagopyrum tataricum (L.) Gaertn (tartary buckwheat) is an ancient dicotyledonous crop belonging to Polygonaceae family. Besides its benefits for human consumption, tartary buckwheat is also an important folk medicine in China for its antioxidant, antitumor, hypotensive, hypoglycemic and hypolipidemic activities. Phytochemical investigation of the ethyl acetate fraction of tartary buckwheat roots led to the isolation of seven new phenylpropanoid glycosides,

Chengjian Zheng; Changling Hu; Xueqin Ma; Cheng Peng; Hong Zhang; Luping Qin

132

A new flavone glycoside from seeds of Daucus carota.  

PubMed

Phytochemical examination of seeds of Daucus carota L. resulted in the isolation of apigenin -4'-O-beta-D-glucoside, kaempferol-3-O-beta-D-glucoside and a new flavone glycoside which was characterised as apigenin-7-O-beta-D-galactopyranosyl-(1-->4)-O-beta-D-mannopyranoside. PMID:17396982

Gupta, K R; Niranjan, G S

1982-12-01

133

Glycosidation of Methanol with Ribose: An Interdisciplinary Undergraduate Laboratory Experiment  

ERIC Educational Resources Information Center

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…

Simon, Erin; Cook, Katie; Pritchard, Meredith R.; Stripe, Wayne; Bruch, Martha; Bendinskas, Kestutis

2010-01-01

134

Physiological functions of solanaceous and tomato steroidal glycosides  

Microsoft Academic Search

Solanaceous plants are widely distributed. They are used as food and in folk medicine. Our studies focused on these plants, starting with Solanum lyratum and S. nigrum, which are used as anti-cancer and anti-herpes agents. Extensive investigations in 45 Solanum plant species revealed that a considerable amount of glycosides such as spirosolane, solanidane, spirostane and furostane is in these plants,

Toshihiro Nohara; Tsuyoshi Ikeda; Yukio Fujiwara; Sayaka Matsushita; Eishin Noguchi; Hitoshi Yoshimitsu; Masateru Ono

2007-01-01

135

Glycosidases and glycosyl transferases in glycoside and oligosaccharide synthesis  

Microsoft Academic Search

Remarkable advances in glycobiology in recent years have stimulated a resurgence of interest in carbohydrate chemistry. The challenge of producing the complex glycosides and oligosaccharides needed for research in glycobiology has led to the development of enzymatic methods that are now firmly established as part of the synthetic repertoire of the carbohydrate chemist.

David HG Crout; Gabin Vic

1998-01-01

136

New secoiridoid glycosides from the buds of Lonicera macranthoides.  

PubMed

Two new secoiridoid glycosides, named ethyl secologanoside (1) and 6'-O-alpha-L-arabinopyranosyl demethylsecologanol (2), together with three known ones, secologanoside (3), secoxyloganin (4), and loniceroside (5), were isolated from the dried buds of Lonicera macranthoides. The structures of the new compounds were determined on the basis of detailed spectroscopic analyses and acidic hydrolysis. PMID:23413549

Liu, Jiang; Zhang, Jing; Wang, Feng; Chen, Xingfu

2012-12-01

137

Chemically Synthesized Oligosaccharides, 1994. A Searchable Table of Glycosidic Linkages  

Microsoft Academic Search

This review of the literature on oligosaccharide synthesis tabulates over 700 glycosidic linkages that have been chemically synthesized in the “popular literature” in the year 1994. The “popular literature” consists of the following journals, most frequently used for reporting oligosaccharide synthesis: Acta Chem. Scand., Angew. Chem. Intl. Ed. Engl., Aust. J. Chem., Bioorg. Med. Chem., Bioorg. Med. Chem. Lett., Bull.

Frank Barresi; Ole Hindsgaul

1995-01-01

138

New and rare flavonol glycosides from leaves of Syzygium samarangense  

Microsoft Academic Search

Two flavonol glycosides have been isolated and characterised from leaves of Syzygium samarangense. One is the rare mearnsitrin (1) while the second, 2?-C-methyl-5?-O-galloylmyricetin-3-O-a-l-rhamnopyranoside (2), is new. Detailed spectral data are provided for both.

A. G. R Nair; S Krishnan; C Ravikrishna; K. P Madhusudanan

1999-01-01

139

Melanogenesis inhibitory activity of monoterpene glycosides from Gardeniae Fructus.  

PubMed

A new iridoid glycoside, 10-O-(4"-O-methylsuccinoyl)geniposide (7), and two new pyronane glycosides, jasminosides Q and R (13 and 14, resp.), along with nine known iridoid glycosides, 1-6 and 8-10, and two known pyronane glycosides, 11 and 12, were isolated from a MeOH extract of Gardeniae Fructus, the dried ripe fruit of Gardenia jasminoides (Rubiaceae). The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses and comparison with literature. Upon evaluation of compounds 1-14 on the melanogenesis in B16 melanoma cells induced with ?-melanocyte-stimulating hormone (?-MSH), three compounds, i.e., 6-O-p-coumaroylgeniposide (3), 7, and 6'-O-sinapoyljasminoside (12), exhibited inhibitory effects with 21.6-41.0 and 37.5-47.7% reduction of melanin content at 30 and 50 ?M, respectively, with almost no toxicity to the cells (83.7-106.1% of cell viability at 50 ?M). PMID:22899609

Akihisa, Toshihiro; Watanabe, Kensuke; Yamamoto, Ayako; Zhang, Jie; Matsumoto, Masahiro; Fukatsu, Makoto

2012-08-01

140

Absence of cyanogenic glycosides in the tribe Miconieae (Melastomataceae)  

Microsoft Academic Search

In order to compare ant and non-ant defended species of Melastomataceae, production of hydrogen cyanide gas was tested in the field for 51 species of 10 genera of the tribe Miconieae. Using both the picric acid and the Feigl–Anger tests all populations surveyed tested negative for the presence of cyanogenic glycosides. These results confirm that cyanogenesis is rare in the

Fabián A. Michelangeli; Eloy Rodriguez

2005-01-01

141

Antioxidant flavonol glycosides from Elaeocarpus serratus and Filicium decipiens.  

PubMed

Chemical investigation of the leaves of Elaeocarpus serratus yielded myricitrin (1), mearnsetin 3-O-?-D-glucopyranoside (2), mearnsitrin (3), tamarixetin 3-O-?-L-rhamnopyranoside (4) and the fruits of Filicium decipiens yielded three flavonol glycosides, kaempferol 3-O-rutinoside (5), kaempferol 3-O-robinobioside (6) and trifolin (7). Compound 1 showed strong antioxidant activity against DPPH. PMID:21923561

Jayasinghe, Lalith; Amarasinghe, Nilupa R; Arundathie, B G Suranga; Rupasinghe, G Kalinga; Jayatilake, N H Ayona N; Fujimoto, Yoshinori

2011-09-19

142

Glycosidation of Methanol with Ribose: An Interdisciplinary Undergraduate Laboratory Experiment  

ERIC Educational Resources Information Center

|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…

Simon, Erin; Cook, Katie; Pritchard, Meredith R.; Stripe, Wayne; Bruch, Martha; Bendinskas, Kestutis

2010-01-01

143

Curation of characterized glycoside hydrolases of Fungal origin  

PubMed Central

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/

Murphy, Caitlin; Powlowski, Justin; Wu, Min; Butler, Greg; Tsang, Adrian

2011-01-01

144

Functional genomic analysis of Arabidopsis thaliana glycoside hydrolase family 35  

Microsoft Academic Search

Catalysing the hydrolysis of terminal ?-galactosyl residues from carbohydrates, galactolipids, and glycoproteins, glycoside hydrolase family 35 (?-galactosidases; BGALs) are widely distributed in plants and believed to play many key roles, including modification of cell wall components. Completion of the Arabidopsis thaliana genome sequencing project has, for the first time, allowed an examination of the total number, gene structure, and evolutionary

Young Ock Ahn; Meiying Zheng; David R. Bevan; Asim Esen; Shin-Han Shiu; Jonas Benson; Hsiao-Ping Peng; Joseph T. Miller; Chi-Lien Cheng; Jonathan E. Poulton; Ming-Che Shih

2007-01-01

145

Computational analysis of the phylogeny and thermodynamics of glycoside hydrolases  

Microsoft Academic Search

My research has focused on using computation by means of phylogenetic analysis and molecular mechanics docking studies to further extend knowledge of glycoside hydrolases (GHs). Phylogenetic analysis was used to crystallize the fundamental differences between specific types of cellulases in GH family 6 (GH6). Cellulase enzymes were then examined for functional divergence in order to determine the cause of substrate

John Blakely Mertz

2008-01-01

146

Two new flavonol glycosides from Gymnema sylvestre and Euphorbia ebracteolata  

Microsoft Academic Search

Two new flavonol glycosides, namely kaempferol 3-O-?-d-glucopyranosyl-(1?4)-?-l-rhamnopyranosyl-(1?6)-?-d-galactopyranoside (1) and quercetin 3-O-6?-(3-hydroxyl-3-methylglutaryl)-?-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.

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

2004-01-01

147

Reverse Logistics.  

National Technical Information Service (NTIS)

The Army has a serious problem with materiel in the supply chain that is moving in the reverse direction. The supply chain is a series of inter- related processes and activities that move supplies and services from the suppliers to the ultimate end users....

J. L. Walden

2001-01-01

148

Inhibition of Steryl Glycoside Biosynthesis by Acyl Coenzyme A and by Digitonin  

PubMed Central

ATP, GTP, CoA, Mg2+, and Mn2+ did not inhibit biosynthesis of steryl glycoside and acylated steryl glycoside when added singly to enzyme preparations from spinach leaves. The combination of ATP (but not GTP), CoA, and Mg2+ or Mn2+ caused marked inhibition, especially of steryl glycoside biosynthesis, when reaction mixture concentrations of the additions were 0.2 millimolar. Inhibition was attributed to acyl-CoA and could be reproduced by palmitoyl-CoA. The inhibition could be partially prevented by bovine serum albumin. The effects of palmitoyl-CoA were distinct at 10 micromolar, and 50% inhibition of biosynthesis was observed at 40 micromolar. Digitonin (0.6 millimolar) stopped steryl glycoside biosynthesis but permitted the conversion of steryl glycoside to acylated steryl glycoside, thus eliminating the possibility that acylated steryl glycoside is formed from sterol + an acyl-glucose donor.

Garcia, Raymond E.; Mudd, J. Brian

1980-01-01

149

Gold-catalyzed glycosidations: unusual cleavage of the interglycosidic bond while studying the armed\\/disarmed effect of propargyl glycosides  

Microsoft Academic Search

Armed\\/disarmed effect of propargyl glycosides in the presence of AuBr3 is studied. Observed that oxophilic AuBr3 cleaves interglycosidic bond of an armed disaccharide resulting in the formation of a disaccharide and a 1,6-anhydro sugar. Trisaccharides were obtained after fine tuning the reactivity of the glycosyl donor with different protecting groups.

Abhijeet K. Kayastha; Srinivas Hotha

2010-01-01

150

Reverse Presentations  

Microsoft Academic Search

Reverse Presentations is a method for requirements validation in offshore software development. In this paper, the authors\\u000a present and conceptually refine this method and carry out an initial evaluation. The method provides cross-phase support and\\u000a is characterized by a structured and iterative validation process. In contrast to existing methods, it focuses on the client\\u000a perspective and takes into account social

Martin Wiener; Rolf Stephan

2010-01-01

151

Reverse Osmosis  

NSDL National Science Digital Library

North Dakota State University presents the theories behind reverse osmosis and how it affects household water supplies. The site addresses the impurities which are removed by this process. It also speaks of testing, the process itself and even the disadvantages of this process. A fairly encompassing site is what amounts from the work done by the University, it gives a clear and concise viewpoint of this process.

2008-10-13

152

Reverse convection  

SciTech Connect

A model of magnetospheric topology for periods when the interplanetary magnetic field (IMF) points northward indicates that reverse convection can readily occur when Earth's dipole or the IMF tilt toward or away from the Sun. In either case, all or part of one tail lobe drapes over the dayside, and the magnetopause merging voltage is applied directly to the ionosphere in that lobe only, to the center or nightside of the polar cap. The overdraped lobe forms layers both earthward and sunward of the magnetopause, similar to layers observed during periods of northward IMF. The model predicts two quasi-steady state patterns of reverse convection: (1) lobe cells in the polar cap of the overdraped lobe, generated by open-to-open flux transfer at the magnetopause and (2) merging cells in both polar caps, generated by closed-to-open flux transfer at the magnetopause and balanced open-to-closed transfer at an internal reconnection site, comparable to the tail merging site for southward IMF. The model also predicts transitional patterns of reverse convection for growing and shrinking polar caps in response to changes in dipole tilt and B[sub x] and in response to a sudden transition from southward to northward IMF. The model predicts theta aurora bar formation on the dawnside polar cap boundary when activation of the internal reconnection site ends polar cap growth. In this view the theta aurora becomes the northward IMF counterpart to substorms.

Crooker, N.U. (Univ. of California, Los Angeles (United States))

1992-12-01

153

Dynamics of the glycosidic bond: conformational space of lactose.  

PubMed

The dynamics of the glycosidic bond of lactose was studied by a paramagnetic tagging-based NMR technique, which allowed the collection of an unusually large series of NMR data for a single compound. By the use of distance- and orientation-dependent residual dipolar couplings and pseudocontact shifts, the simultaneous fitting of the probabilities of computed conformations and the orientation of the magnetic susceptibility tensor of a series of lanthanide complexes of lactose show that its glycosidic bond samples syn/syn, anti/syn and syn/anti ?/? regions of the conformational space in water. The analysis indicates a higher reliability of pseudocontact shift data as compared to residual dipolar couplings with the presently available weakly orienting paramagnetic tagging technique. The method presented herein allows for an improved understanding of the dynamic behaviour of oligosaccharides. PMID:21755545

Erdélyi, Máté; d'Auvergne, Edward; Navarro-Vázquez, Armando; Leonov, Andrei; Griesinger, Christian

2011-07-13

154

Isoflavanones and their O-glycosides from Desmodium styracifolium.  

PubMed

Two isoflavanones (5,7-dihydroxy-2',3',4'-trimethoxy-isoflavanone and 5,7-dihydroxy-2'-methoxy-3',4'-methylenedioxy-isoflavanone), four isoflavanone O-glycosides (5,7-dihydroxy-2',3',4'-trimethoxy-isoflavanone 7-O-beta-glucopyranoside, 5,7-dihydroxy-2'-methoxy-3',4'-methylenedioxy-isoflavanone 7-O-beta-glucopyranoside, 5,7-dihydroxy-2',4'-dimethoxy-isoflavanone 7-O-beta-glucopyranoside, and 5,7,4'-trihydroxy-2',3'-dimethoxy-isoflavanone 7-O-beta-glucopyranoside), and a coumaronochromone (3,5,7,4'-tetrahydroxy-coumaronochromone), along with 25 known compounds, were isolated from the aerial parts of Desmodium styracifolium. This is for the first time isoflavanone O-glycosides were isolated from a natural source. PMID:17434190

Zhao, Ming; Duan, Jin-Ao; Che, Chun-Tao

2007-04-16

155

A novel cytotoxic flavonoid glycoside from Physalis angulata.  

PubMed

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. PMID:11543968

Ismail, N; Alam, M

2001-08-01

156

New coumarin glycosides from the leaves of Diospyros crassiflora (Hiern)  

Microsoft Academic Search

Two new 5-methylcoumarin glycosides named diosfeboside A (1) and B (2) and five known compounds namely kaempferol 3-O-?-l-rhamnopyranosyl-(1?2)-?-d-glucopyranoside (3), ursolic acid (4), betulinic acid (5), stigmasterol (6) and stigmasterol 3-O-?-d-glucopyranoside (7) were isolated from the leaves of Diospyros crassiflora (Hiern). Their structures were established through interpretation of 1 and 2D NMR, mass spectra analysis and comparison with reported data. In

Carine Mvot Akak; Céline Mbazoa Djama; Augustin Ephrem Nkengfack; Peng-Fei Tu; Lian-Di Lei

2010-01-01

157

New monocyclic monoterpenoid glycoside from Mentha haplocalyx Briq.  

PubMed Central

Two new monocyclic monoterpenoid glycosides, rel-(1R,2S,3R,4R) p-menthane-1,2,3-triol 3-O-?-D-glucopyranoside (1) and rel- (1S,2R,3S) terpinolene-1,2,3-triol 3-O-?-D-glucopyranoside (2) were isolated from aqueous acetone extract of the aerial parts of Mentha haplocalyx Briq.. Their structures were elucidated through spectral analysis using MS and NMR spectrometers.

2012-01-01

158

Comparative topo-optical investigation of cardiac glycoside localization  

Microsoft Academic Search

Summary The aldehyde-bisulfite-toluidine blue (ABT) reaction is a selective topo-optical test of vicinal-OH and amino-OH groups. The localization of cardiac glycoside was investigated morphologically. After digoxin the sarcolemma membranes, capillaries and sinus node showed strong basophilia and negative birefringence. The topo-optical reaction are useful for the histopathological examination. The new method gives the possibility to the digoxin intoxication with a

P. Sótonyi; E. Somogyi

1983-01-01

159

A new acylated flavone glycoside from Colebrookea oppositifolia  

Microsoft Academic Search

A new acylated flavone glycoside, echioidinin 2?-O-?-d-(2?-O-acetyl)glucopyranoside (1) along with the three known flavonoids, 5,6,7,8,5?-pentamethoxy-3?,4?-methylenedioxyflavone (2), 5,2?,6?-trihydroxy-7-methoxyflavone (3), and kaempferol 7,4?-dimethyl ether 3-O-?-d-glucopyranoside (4), were isolated from the roots of Colebrookea oppositifolia. The structure of compound 1 was elucidated by extensive spectral and chemical studies.

Ramireddy Venkata Narahari Reddy; Bandi Anil Kumar Reddy; Duvvuru Gunasekar

2009-01-01

160

Ent -kaurane diterpenoids and glycosides: Isolation, properties, and chemical transformations  

Microsoft Academic Search

This review is devoted to ent-kaurane diterpenoids and related glycosides, which represent two naturally occurring groups of compounds with interesting\\u000a structures and properties. Much useful information about the biogenesis and biological activities of these compounds is presented;\\u000a however, the greatest part of the review covers various aspects of the chemical transformations of native ent-kaurane diterpenoids, namely, their reactions via COOH,

E. Kataev; R. N. Khaybullin; R. R. Sharipova; I. Yu. Strobykina

2011-01-01

161

Two acetylated megastigmane glycosides from the leaves of Ilex paraguariensis.  

PubMed

Two acetylated megastigmane glycosides, matenosides A (1) and B (2), have been isolated from the MeOH extract of Ilex paraguariensis leaves, and their structures were elucidated on the basis of spectroscopic analysis. Compounds 1 and 2 exhibited human neutrophil elastase (HNE) inhibitory activity with IC(50) values of 50.4 muM and 11.1 microM, respectively. PMID:20361300

Xu, Guang-Hua; Kim, Young-Hee; Choo, Soo-Jin; Ryoo, In-Ja; Yoo, Jae-Kuk; Ahn, Jong-Seog; Yoo, Ick-Dong

2010-03-30

162

A new phenolic glycoside and cytotoxic constituents from Celosia argentea.  

PubMed

A new phenolic glycoside, 4-O-?-D-apifuranosyl-(1?2)-?-D-glucopyranosyl-2-hydroxy-6-methoxyacetophenone (2) and 11 known compounds were isolated from the MeOH extract of the plant Celosia argentea. The structures of the compounds were elucidated on the basis of spectroscopic analysis and chemical methods. Among the isolated compounds, stigmasterol (10) showed moderate inhibitory activities against SGC-7901 and BEL-7404 cells. PMID:20839132

Shen, Shuo; Ding, Xiao; Ouyang, Ming-An; Wu, Zu-Jian; Xie, Lian-Hui

2010-09-01

163

A new phenolic glycoside and cytotoxic constituents from Celosia argentea  

Microsoft Academic Search

A new phenolic glycoside, 4-O-?-D-apifuranosyl-(1 ? 2)-?-D-glucopyranosyl-2-hydroxy-6-methoxyacetophenone (2) and 11 known compounds were isolated from the MeOH extract of the plant Celosia argentea. The structures of the compounds were elucidated on the basis of spectroscopic analysis and chemical methods. Among the isolated compounds, stigmasterol (10) showed moderate inhibitory activities against SGC-7901 and BEL-7404 cells.

Shuo Shen; Xiao Ding; Ming-An Ouyang; Zu-Jian Wu; Lian-Hui Xie

2010-01-01

164

Ethoxylated glycerol and propylene glycol glycoside palmitates from lactose  

Microsoft Academic Search

Polyoxyethylene polyol glycoside palmitates were prepared by the following successive reactions: transglycosylation of lactose\\u000a by glycerol and propylene glycol to yield crude mixtures of the polyol glucosides and galactosides; alkoxylation with ethylene\\u000a oxide; and tranesterfication by methyl palmitate. Almost all the solid waxy products exhibited low surface and interfacial\\u000a tensions and good emulsion stability; they are expected to be effective

C. L. Mehltretter; C. A. Wilham

1973-01-01

165

Two new flavonol glycosides from Gymnema sylvestre and Euphorbia ebracteolata.  

PubMed

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. PMID:14980834

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

2004-03-15

166

Glycosidically bound flavor compounds of cape gooseberry (Physalis peruviana L.).  

PubMed

The bound volatile fraction of cape gooseberry (Physalis peruviana L.) fruit harvested in Colombia has been examined by HRGC and HRGC-MS after enzymatic hydrolysis using a nonselective pectinase (Rohapect D5L). Forty bound volatiles could be identified, with 21 of them being reported for the first time in cape gooseberry. After preparative isolation of the glycosidic precursors on XAD-2 resin, purification by multilayer coil countercurrent chromatography and HPLC of the peracetylated glycosides were carried out. Structure elucidation by NMR, ESI-MS/MS, and optical rotation enabled the identification of (1S,2S)-1-phenylpropane-1,2-diol 2-O-beta-D-glucopyranoside (1) and p-menth-4(8)-ene-1,2-diol 1-O-alpha-L-arabinopyranosyl-(1-6)-beta-D-glucopyranoside (2). Both glycosides have been identified for the first time in nature. They could be considered as immediate precursors of 1-phenylpropane-1,2-diol and p-menth-4(8)-ene-1,2-diol, typical volatiles found in the fruit of cape gooseberry. PMID:11308344

Mayorga, H; Knapp, H; Winterhalter, P; Duque, C

2001-04-01

167

Development and application of a screening assay for glycoside phosphorylases.  

PubMed

Glycoside phosphorylases (GPs) are interesting enzymes for the glycosylation of chemical molecules. They require only a glycosyl phosphate as sugar donor and an acceptor molecule with a free hydroxyl group. Their narrow substrate specificity, however, limits the application of GPs for general glycoside synthesis. Although an enzyme's substrate specificity can be altered and broadened by protein engineering and directed evolution, this requires a suitable screening assay. Such a screening assay has not yet been described for GPs. Here we report a screening procedure for GPs based on the measurement of released inorganic phosphate in the direction of glycoside synthesis. It appeared necessary to inhibit endogenous phosphatase activity in crude Escherichia coli cell extracts with molybdate, and inorganic phosphate was measured with a modified phosphomolybdate method. The screening system is general and can be used to screen GP enzyme libraries for novel donor and acceptor specificities. It was successfully applied to screen a residue E649 saturation mutagenesis library of Cellulomonas uda cellobiose phosphorylase (CP) for novel acceptor specificity. An E649C enzyme variant was found with novel acceptor specificity toward alkyl beta-glucosides and phenyl beta-glucoside. This is the first report of a CP enzyme variant with modified acceptor specificity. PMID:20188057

De Groeve, M R M; Tran, G H; Van Hoorebeke, A; Stout, J; Desmet, T; Savvides, S N; Soetaert, W

2010-02-24

168

Taxifolin Glycoside Blocks Human ether-a-go-go Related Gene K+ Channels  

PubMed Central

Taxifolin glycoside is a new drug candidate for the treatment of atopic dermatitis (AD). Many drugs cause side effects such as long QT syndrome by blocking the human ether-a-go-go related gene (hERG) K+ channels. To determine whether taxifolin glycoside would block hERG K+ channels, we recorded hERG K+ currents using a whole-cell patch clamp technique. We found that taxifolin glycoside directly blocked hERG K+ current in a concentration-dependent manner (EC50=9.6±0.7 µM). The activation curve of hERG K+ channels was negatively shifted by taxifolin glycoside. In addition, taxifolin glycoside accelerated the activation time constant and reduced the onset of the inactivation time constant. These results suggest that taxifolin glycoside blocks hERG K+ channels that function by facilitating activation and inactivation process.

Yun, Jihyun; Bae, Hyemi; Choi, Sun Eun; Kim, Jung-Ha; Choi, Young Wook; Lim, Inja; Lee, Chung Soo; Lee, Min Won; Ko, Jae-Hong; Seo, Seong Jun

2013-01-01

169

Annotation and comparative analysis of the glycoside hydrolase genes in Brachypodium distachyon  

PubMed Central

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, at the levels of the whole genome and 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. For several glycoside hydrolase familes (GH5, GH13, GH18, GH19, GH28, and GH51), we present a detailed literature review together with an examination of the family structures. This analysis of individual families revealed both similarities and distinctions between monocots and eudicots, as well as between species. Shared evolutionary histories appear to be modified by lineage-specific expansions or deletions. Within GH 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 grass model for investigations of these enzymes and their diverse roles in planta. Insights gained from Brachypodium will inform translational research studies, with applications for the improvement of cereal crops and bioenergy grasses.

2010-01-01

170

Proanthocyanidin glycosides and related polyphenols from cacao liquor and their antioxidant effects  

Microsoft Academic Search

Purification of polar fractions from cacao liquor extracts gave 17 phenolics including four new compounds. The new compounds were characterized as a C-glycosidic flavan, an O-glycoside of a dimeric and two O-glycosides of trimeric A-linked proanthocyanidins, on the basis of spectroscopic data. Isolated polyphenols showed inhibitory effects on nicotinamide adenine dinucleotide phosphate-dependent lipid peroxidation in microsomes and on the autoxidation

Tsutomu Hatano; Haruka Miyatake; Midori Natsume; Naomi Osakabe; Toshio Takizawa; Hideyuki Ito; Takashi Yoshida

2002-01-01

171

A comparison of flavonoid glycosides by electrospray tandem mass spectrometry  

NASA Astrophysics Data System (ADS)

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.

March, Raymond E.; Lewars, Errol G.; Stadey, Christopher J.; Miao, Xiu-Sheng; Zhao, Xiaoming; Metcalfe, Chris D.

2006-01-01

172

MATE2 Mediates Vacuolar Sequestration of Flavonoid Glycosides and Glycoside Malonates in Medicago truncatula[C][W][OA  

PubMed Central

The majority of flavonoids, such as anthocyanins, proanthocyanidins, and isoflavones, are stored in the central vacuole, but the molecular basis of flavonoid transport is still poorly understood. Here, we report the functional characterization of a multidrug and toxin extrusion transporter (MATE2), from Medicago truncatula. MATE 2 is expressed primarily in leaves and flowers. Despite its high similarity to the epicatechin 3?-O-glucoside transporter MATE1, MATE2 cannot efficiently transport proanthocyanidin precursors. In contrast, MATE2 shows higher transport capacity for anthocyanins and lower efficiency for other flavonoid glycosides. Three malonyltransferases that are coexpressed with MATE2 were identified. The malonylated flavonoid glucosides generated by these malonyltransferases are more efficiently taken up into MATE2-containing membrane vesicles than are the parent glycosides. Malonylation increases both the affinity and transport efficiency of flavonoid glucosides for uptake by MATE2. Genetic loss of MATE2 function leads to the disappearance of leaf anthocyanin pigmentation and pale flower color as a result of drastic decreases in the levels of various flavonoids. However, some flavonoid glycoside malonates accumulate to higher levels in MATE2 knockouts than in wild-type controls. Deletion of MATE2 increases seed proanthocyanidin biosynthesis, presumably via redirection of metabolic flux from anthocyanin storage.

Zhao, Jian; Huhman, David; Shadle, Gail; He, Xian-Zhi; Sumner, Lloyd W.; Tang, Yuhong; Dixon, Richard A.

2011-01-01

173

Estimation of aroma glycosides of nutmeg and their changes during radiation processing.  

PubMed

Glycosidically bound volatile compounds of nutmeg were identified as glyco-conjugates of p-cymene-7-ol, eugenol, methoxyeugenol and alpha-terpineol. Using phenyl-beta-glucoside as external standard the contents of these glycosidic precursors were estimated based on the measurement of TLC spot density on a densitometer. p-Cymene-7-ol rutinoside was the major aroma glycoside (3.15 mg/100 g), followed by glucosides of methoxyeugenol (0.61 mg/100 g), eugenol (0.50 mg/100 g) and alpha-terpineol (0.51 mg/100 g). A dose-dependent breakdown of these glycosidic precursors was observed during gamma-radiation processing. Among the four glycosides, alpha-terpineol glucoside was the most sensitive to radiation while p-cymene-7-ol rutinoside was the least sensitive. A reduction in the content of total glycosides by almost 50% was noted at a dose of 5kGy. Partitioning of aroma glycoside into n-butanol from aqueous extracts was found to result in rapid isolation of aroma glycosides, avoiding time consuming pre-purification on Amberlite XAD-2 column. A routine method based on extraction into n-butanol and subsequent quantification of post-irradiation changes in aroma glycosides on a TLC plate using a densitometer is proposed. PMID:16445922

Ananthakumar, Arul; Variyar, Prasad S; Sharma, Arun

2006-01-30

174

Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities and Biological Roles  

PubMed Central

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.

Kalinin, Vladimir I.; Ivanchina, Natalia V.; Krasokhin, Vladimir B.; Makarieva, Tatyana N.; Stonik, Valentin A.

2012-01-01

175

Selective separation of flavonoid glycosides in Dalbergia odorifera by matrix solid-phase dispersion using titania.  

PubMed

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. PMID:21491599

Xu, Lingyan; Shi, Hui; Liang, Tu; Feng, Jiatao; Jin, Yu; Ke, Yanxiong; Liang, Xinmiao

2011-04-13

176

Flavonoid glycoside: a new inhibitor of eukaryotic DNA polymerase alpha and a new carrier for inhibitor-affinity chromatography.  

PubMed

Two flavonoid glycosides, kaempferol 3-O-(6"-acetyl)-beta-glucopyranoside (KAG) and quercetin 3-O-(6"-acetyl)-beta-glucopyranoside (QAG), were found to be inhibitors of eukaryotic DNA polymerases from a Japanese vegetable, Petasites japonicus. These compounds inhibited the activities of mammalian replicative DNA polymerases (i.e., pol alpha, delta, and epsilon), but not other pol beta, eta, kappa, and lambda activities. KAG was a stronger inhibitor and more selective to pol alpha than QAG. The IC(50) values of KAG for pol alpha, delta, and epsilon were 41, 164, and 127 microM, respectively. The pol alpha inhibition by KAG was non-competitive with respect to both the DNA template-primer and the dNTP substrate. KAG and QAG did not influence the activities of prokaryotic DNA polymerases or other mammalian DNA metabolic enzymes such as human immunodeficiency virus type 1 reverse transcriptase, human telomerase, human DNA topoisomerase I and II, T7 RNA polymerase, and bovine deoxyribonuclease I. Therefore, we concluded that these flavonoid glycosides are moderate replicative DNA polymerase inhibitors leaning more relatively to pol alpha, and could be used as chromatographic carriers to purify the DNA polymerases rather than cytotoxic agents. We then made a KAG-conjugated column such as the epoxy-activated Sepharose 6B. In the column, pol alpha was selectively adsorbed and eluted. PMID:12565887

Mizushina, Yoshiyuki; Ishidoh, Tomomi; Kamisuki, Shinji; Nakazawa, Satoshi; Takemura, Masaharu; Sugawara, Fumio; Yoshida, Hiromi; Sakaguchi, Kengo

2003-02-01

177

Kinetics and mechanism of 2,3,5,4'-tetrahydroxystilbene-2-O-?-d-glycoside (THSG) degradation in aqueous solutions.  

PubMed

The hydrolytic kinetics and degradation mechanism of 2,3,5,4'-tetrahydroxystilbene-2-O-?-d-glycoside (THSG) extracted from Radix Polygoni Multiflori (a commonly used official Chinese herbal Heshouwu), were investigated using reversed-phase high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). The influences of pH (1.5-9.9), temperature (25-60°C) and irradiation on the hydrolysis of THSG were studied in aqueous solutions. The results showed that the degradation of THSG was pH-, temperature- and irradiation-dependent and all followed first-order kinetics. The effect of temperature on the rate of THSG degradation was characterized using the Arrhenius equation. Maximum stability of THSG was found at pH 1.5 (t(0.5)=47.57 d). THSG was unstable in alkaline and irradiation conditions. The active energy (E(a)) of THSG degradation in aqueous solution at pH 6.8 (most frequently adopted extract solvent) under lucifugal and irradiation conditions was 47.7kJmol(-1) and 25.3kJmol(-1), respectively. Three hydrolytic products of THSG were identified by LC-MS. Cis-trans isomerism took place under irradiation, and hydrolysis took place in acid-base conditions. Moreover, further oxidation on aglycon occurred after hydrolytic cleavage of phenolic glycoside in acidic conditions. The possible hydrolytic pathways of THSG are proposed. PMID:21282026

Ren, Xiao-liang; Wang, Gui-fang; Wang, Meng; Ou-Yang, Hui-zi; Qi, Ai-di

2010-12-31

178

Separation of flavanone-7-O-glycoside diastereomers and analysis in citrus juices by multidimensional liquid chromatography coupled with mass spectrometry.  

PubMed

The major flavanone-7-O-glycoside constituents in citrus fruit juices (naringin, hesperidin, neohesperidin, narirutin, and eriocitrin) were separated as diastereomers by multidimensional liquid chromatography. The method consisted of coupling two HPLC columns: a reversed-phase (RP(18)) column was used for the separation of flavanone glycosides, which were, then, individually switched into a carboxymethylated beta-cyclodextrin (beta-CD)-based column and resolved as the corresponding stereoisomers. The method was used for the full analysis of flavanone glycosides in fresh hand-squeezed and commercial fruit juices by combining the quantitative estimation with the diastereomeric analysis. Quantitative data were in general consistent with previously reported data in this field. CC-LC isomer analysis was carried out by coupling the beta-CD column with a mass spectrometer operated with negative ion electrospray ionization (ESI-MS). The results showed that hesperidin was present in orange juices almost exclusively as the 2S isomer, whereas narirutin had mainly the 2R configuration. In grapefruit juices (2S)-naringin prevailed with the respect to the 2R isomer, whereas the opposite was true for narirutin. Lemon juices contained eriocitrin stereoisomers in equal amount (50% each), but hesperidin was almost exclusively found as the 2S isomer. Significant differences of the diastereomeric ratios were observed between freshly squeezed juices and juices from commercial sources. PMID:15315361

Aturki, Zeineb; Brandi, Valentina; Sinibaldi, Massimo

2004-08-25

179

DNA barcoding: species delimitation in tree peonies  

Microsoft Academic Search

Delimitations of species are crucial for correct and precise identification of taxa. Unfortunately “species” is more a subjective\\u000a than an objective concept in taxonomic practice due to difficulties in revealing patterns of infra- or inter-specific variations.\\u000a Molecular phylogenetic studies at the population level solve this problem and lay a sound foundation for DNA barcoding. In\\u000a this paper we exemplify the

JinMei Zhang; JianXiu Wang; Tao Xia; ShiLiang Zhou

2009-01-01

180

Steroidal glycosides from the underground parts of Helleborus caucasicus.  

PubMed

Four polyhydroxylated and polyunsaturated furostanol glycosides (1-4), named caucasicosides A (1), B (2), C (3) and D (4), were isolated from the MeOH extract of the underground parts of Helleborus caucasicus, along with four spirostanol derivatives, a furostanol glycoside, a furospirostanol glycoside, 20-hydroxyecdysone and the bufadienolides hellebrigenin and deglucohellebrin. The structures of 1-4 were elucidated as furosta-5,20(22),25(27)-triene-1beta,3beta,11alpha,26-tetrol 26-O-beta-D-glucopyranoside (1), 26-O-beta-D-glucopyranosylfurosta-5,20(22),25(27)-triene-1beta,3beta,11alpha,26-tetrol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (2), 26-O-beta-d-glucopyranosyl-22alpha-methoxyfurosta-5,25(27)-diene-1beta,3beta,11alpha,26-tetrol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (3), 26-O-beta-D-glucopyranosylfurosta-5,20(22),25(27)-triene-1beta,3beta,26-triol 3-O-beta-D-xylopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-4-O-sulfo-alpha-L-arabinopyranoside (4). Structure elucidation was accomplished through the extensive use of 1D- and 2D NMR experiments including 1H-1H (COSY, 1D-TOCSY) and 1H-13C (HSQC, HMBC) spectroscopy along with ESI-MS and HR-ESI-MS. The aglycones of 1-4 have never been reported before. PMID:18226823

Bassarello, Carla; Muzashvili, Tamara; Skhirtladze, Alexandre; Kemertelidze, Ether; Pizza, Cosimo; Piacente, Sonia

2008-01-28

181

Triterpenoid glycosides from the leaves of two cultivars of Medicago polymorpha L.  

PubMed

The saponin composition of leaves from the Medicago polymorpha cultivars 'Santiago' and 'Anglona' belonging to the botanical varieties brevispina and vulgaris, respectively, was investigated by a combination of chromatographic, spectroscopic, and spectrometric techniques. Several compounds were detected and quantitated by HPLC analysis using the external standard method. Twelve triterpene saponins (1-12) were purified by reverse-phase chromatography and their structures elucidated by spectroscopic (1D and 2D NMR, ESI-MS/MS) and chemical methods. They were identified as glycosides of echinocystic acid, hederagenin, caulophyllogenin, bayogenin, and soyasapogenol B. Two of them (2, 10) were previously reported in M. polymorpha; five of them (4, 6, 7, 9, 12) were already identified in other Medicago species; and three of them (1, 8, 11) were found in other plant genera. The two saponins identified as 3-O-?-L-arabinopyranosyl-28-O-[?-D-glucopyranosyl(1?6)?-D-glucopyranoside] echinocystic acid (3) and 3-O-?-L-arabinopyranosyl-28-O-?-D-glucopyranoside echinocystic acid (5) are newly identified natural compounds. The presence of echinocystic acid is reported here for the first time in the genus Medicago. Saponins from the cultivar 'Anglona' were characterized by a higher amount of echinocystic acid glycosydes, whereas saponins from the cultivar 'Santiago' were characterized by a higher amount of hederagenin glycosydes. PMID:21526796

Tava, Aldo; Pecetti, Luciano; Romani, Massimo; Mella, Mariella; Avato, Pinarosa

2011-05-13

182

[Effects of cornel iridoid glycoside on activity of cholinesterases in vitro].  

PubMed

The purpose of the present study was to investigate the effects of cornel iridoid glycoside (CIG) on the activity of cholinesterases in vitro, and to investigate the mechanism of CIG's treating Alzheimer's disease (AD). The sources of cholinesterases were prepared from human blood cells, rat brain homogenate and human blood plasma, respectively. The biochemical methods were used to detect the activity of acetylcholine esterase (AChE) and butyryl cholinesterase (BuChE) to investigate the influence of CIG on cholinesterases. The results showed that CIG inhibited the activity of AChE of human blood cells and rat brain homogenate, with the 50% inhibition rate (IC50) of 1.6 g . L-1 and 3.3 g . L-1, respectively; and the inhibition of AChE of CIG is reversible. CIG also inhibited the activity of BuChE of human blood plasma, with the IC50 of 2.9 g . L-1. In conclusion, CIG can inhibit the activity of AChE and BuChE in vitro, which may be one of the mechanisms of CIG to treat AD. PMID:23944063

Chu, Si-Juan; Zhang, Lan; Liu, Gang; Zhou, Wen-Xia; Li, Lin

2013-05-01

183

Molecular cloning of glycoside hydrolase family 45 cellulase genes from brackish water clam Corbicula japonica.  

PubMed

We previously reported endogenous Glycoside Hydrolase Family (GHF) 9 beta-1,4-glucanase gene, CjCel9A, from common Japanese freshwater clam Corbicula japonica. Here we identified another endogenous beta-1,4-glucanase genes which belong to GHF45 (CjCel45A, CjCel45B). Both genes encode ORF of 627 bp corresponding to 208 amino acids. CjCel45A and CjCel45B are different in 5' and 3'-untranslated regions and six nucleotides in the ORF. CjCEL45 has only one GHF45 catalytic domain without any carbohydrate binding modules as is the case with other molluskan GHF45 enzymes. Phylogenetic analysis and genomic structure of CjCel45 gene implies that this gene is likely to be acquired from fungi by common ancestor of mollusks. Reverse transcription (RT)-PCR analysis and in situ hybridization revealed that CjCel45A is likely to be expressed in the secretory cells in the digestive gland, suggesting that this cellulase is produced in the same site as CjCEL9A. CjCEL45A was successfully expressed in E. coli cells and zymographic analysis of the recombinant CjCEL45A showed that CjCEL45A is a functional beta-1,4-glucanase. The finding of multiple cellulase genes in C. japonica strongly supports our hypothesis that this species function as a cellulose decomposer in estuarine environments. PMID:19266619

Sakamoto, Kentaro; Toyohara, Haruhiko

2009-04-01

184

Triterpenoids and their glycosides from the bark of Schefflera octophylla.  

PubMed

A new triterpene and its glycosides were isolated from the bark of Schefflera octophylla together with asiatic acid and asiaticoside. Based on spectroscopic data, especially 2DNMR, and chemical transformations the structures of the new compounds were determined as 3 alpha-hydroxy-urs-12-ene-23,28-dioic acid and 3 alpha-hydroxy-urs-12-ene-23,28-dioic acid 28-O-[alpha-L-rhamnopyranosyl (1----4)-O-beta-D-glucopyranosyl (1----6)]-beta-D-glucopyranoside. For the first time asiaticoside was isolated from a plant other than Centella asiatica. PMID:1367880

Sung, T V; Lavaud, C; Porzel, A; Steglich, W; Adam, G

1992-01-01

185

Gmelinoside I, a new flavonol glycoside from Limonium gmelinii.  

PubMed

Gmelinoside I (1), a new flavonol glycoside, was isolated and chemically characterized as 3,5,7,3',4',5'-hexahydroxy-3-O-alpha-D-galactopyranosylflavone from the aerial part of Limonium gmelinii Kuntze (Plumbaginaceae).. Other compounds were identified as (-)-epigallocatechin-3-O-gallate, myricetin, myricetin-3-O-alpha-L-rhamnopyranoside, myricetin-3-O-beta-D-galactoside-6"-O-gallate and caprolactam. The antibacterial, antifungal and antileishmanial activities of the isolated compounds were evaluated. Myricetin showed moderate antileishmanial activity. PMID:20734940

Kozhamkulova, Zhanar A; Radwan, Mohamed M; Zhusupova, Galiya E; Abilov, Zharilkasin Zh; Rahadilova, Saniya N; Ross, Samir A

2010-07-01

186

Two new glycosides from the fruits of Morinda citrifolia L.  

PubMed

To study the chemical constituents of the fruits of noni (Morinda citrifolia L.), and find novel compounds, an n-butanol extract of the ethanol soluble fraction was subjected to repeated silica gel and ODS column chromatography and HPLC. Two new glycosides were isolated and their structures elucidated by NMR and HRFAB-MS spectrometry as (2E,4E,7Z)-deca-2,4,7-trienoate-2-O-?-D-glucopyranosyl-?-D-glucopyranoside and amyl-1-O-?-D-apio-furanosyl-1,6-O-?-D-glucopyranoside, respectively. PMID:23103531

Hu, Ming-Xu; Zhang, Hong-Cai; Wang, Yu; Liu, Shu-Min; Liu, Li

2012-10-26

187

Triterpene glycosides from Curculigo orchioides and their cytotoxic activity.  

PubMed

Six new cycloartane glycosides (1-6) were isolated from the rhizomes of Curculigo orchioides. The structures of 1-6 were determined by spectroscopic analyses and the results of hydrolytic cleavage. Compounds 1-6, and their common aglycone (1a), were evaluated for cytotoxic activity against HL-60 human leukemia cells. Compounds 1 and 1a showed cytotoxic activity against HL-60 cells with IC(50) values of 9.0 and 1.8 microM, respectively. The cancer cell growth inhibition of 1a was also examined using a panel of 39 human cancer cell lines in the Japanese Foundation for Cancer Research. PMID:20524638

Yokosuka, Akihito; Sato, Koji; Yamori, Takao; Mimaki, Yoshihiro

2010-06-25

188

Three new phenolic glycosides from Curculigo orchioides G.  

PubMed

Three new phenolic glycosides, curculigosides F-H (1-3), were isolated from rhizomes of Curculigo orchioides Gaertn. Their structures were elucidated based on comprehensive spectroscopic analyses including IR, MS, 1D- and 2D NMR (HSQC, COSY, and HMBC). Curculigosides F-H (1-3) were evaluated for their anti-HBV activity in vitro using the HBV transfected Hep G2.2.15 cell line. Compound 1 exhibited weak activity with an IC(50) value of 2.08 mM on hepatitis B virus (HBV) e antigen (HBeAg) secretion of the HepG2.2.15 cell line. PMID:20550957

Zuo, Ai-Xue; Shen, Yong; Jiang, Zhi-Yong; Zhang, Xue-Mei; Zhou, Jun; Lü, Jun; Chen, Ji-Jun

2010-06-13

189

Four new trace phenolic glycosides from Curculigo orchioides.  

PubMed

Four new trace phenolic glycosides named orcinosides D (1), E (2), F (3), and G (4) were isolated from the rhizomes of Curculigo orchioides Gaertn. Based on comprehensive spectroscopic analyses including IR, FAB-MS, HR-ESI-MS, 1D- and 2D NMR (HSQC, HMBC), their structures were elucidated as orcinol-1-O-beta-D-xylopyranoside (1), orcinol-1-O-beta-D-apiofuranosyl-(1 --> 2)-beta-D-glucopyranoside (2), orcinol-3-O-beta-D-apiofuranosyl-1-O-beta-D-glucopyranoside (3), and 1-O-beta-D-glucopyranosyl-4-ethoxyl-3-hydroxymethylphenol (4). PMID:20390742

Zuo, Ai-Xue; Shen, Yong; Zhang, Xue-Mei; Jiang, Zhi-Yong; Zhou, Jun; Lu, Jun; Chen, Ji-Jun

2010-01-01

190

Acylated flavonol glycosides from the flower of Inula britannica.  

PubMed

Three new acylated flavonol glycosides, patuletin 7-O-(6' '-isobutyryl)glucoside (1), patuletin 7-O-[6' '-(2-methylbutyryl)]glucoside (2), and patuletin 7-O-(6' '-isovaleryl)glucoside (3), were isolated from the n-BuOH extract of Inula britannica flowers by bioassay-guided fractionation, together with other known flavonoids. The structures were elucidated by 1D and 2D NMR, FABMS, and other spectral analyses. The eight flavonoids, including new compounds (1-3), patulitrin (7), nepitrin (8), axillarin (10), patuletin (11), and luteolin (12), showed profound antioxidant activity in DPPH assay and cytochrome-c reduction assay using HL-60 cell culture system. PMID:10650074

Park, E J; Kim, Y; Kim, J

2000-01-01

191

Isoflavonoid glycosides from the flowers of Pueraria lobata.  

PubMed

Pueraria lobata flower is a medicinal herb for treating intoxication, hepatic, and gastrointestinal tract lesions induced by alcohol. This study aims to investigate the isoflavonoid glycosides in P. lobata flowers. Two new isoflavone compounds were isolated from the extract of P. lobata flowers. Their structures were determined to be 5,6,7,4'-tetrahydroxyisoflavone-6,7-di-O-?-D-glucopyranoside and 5,6,7-trihydroxy-4'-methoxyisoflavone-6,7-di-O-?-D-glucopyranoside on the basis of spectroscopic means including HR-ESI-MS, UV, IR, ąH, and ąłC NMR. PMID:21462030

Yu, Ying-Lu; Liao, Yi-Ting; Li, Xian; Ye, Yang; Ke, Chang-Qiang; Li, Xi-Qiang; Yang, Xin-Zhou; Yao, Mei-Cun

2011-04-01

192

Iodine-hexamethyldisilane (HMDS)-mediated anomerization of peracetylated 1,2-trans-linked alkyl and aryl glycosides  

Microsoft Academic Search

Treatment of peracetylated alkyl and aryl 1,2-trans-glycosides with iodine in the presence of HMDS has been found to result in the anomerization leading to the formation of the respective 1,2-cis-glycosides. In the case of alkyl glycosides with aglycons of short alkyl chain length complete anomerization to the ?-glycosides was observed while with those of longer chain length the process was

Satish Malik; Krupesh J. Shah; K. P. Ravindranathan Kartha

2010-01-01

193

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...

194

Alkane1,2-diol-based glycosides and fatty glycosides and wax esters in Roseiflexus castenholzii and hot spring microbial mats  

Microsoft Academic Search

The lipid composition of Roseiflexus castenholzii, a thermophilic filamentous phototrophic bacterium related to uncultivated filamentous phototrophic bacteria that predominate in hot spring microbial mats, is reported. R. castenholzii lipid extracts were dominated by components characterized by alkane-1-ol-2-alkanoate moieties glycosidically bonded to a C6 sugar. Similar fatty glycosides, with an additional fatty acid esterified, were detected by HPLC-MS. R. castenholzii also

Stefan Schouten; Satoshi Hanada; Ellen C. Hopmans; Jaap S. Sinninghe Damsté; David M. Ward

2002-01-01

195

Host plant influences on iridoid glycoside sequestration of generalist and specialist caterpillars.  

PubMed

The effect of diet on sequestration of iridoid glycosides was examined in larvae of three lepidopteran species. Larvae were reared upon Plantago major, or P. lanceolata, or switched from one to the other in the penultimate instar. Junonia coenia is a specialist on iridoid glycoside-producing plants, whereas the arctiids, Spilosoma congrua and Estigmene acrea, are both polyphagous and eat iridoid-producing plants. All species sequestered iridoids. The specialist J. coenia sequestered from three to seven times the amounts sequestered by the two generalist species. Junonia coenia iridoid glycoside content depended on diet, and they sequestered from 5 to 15% dry weight iridoid glycosides. Estigmene acrea iridoid glycoside sequestration was relatively low, around 2% dry weight and did not vary with diet. Spilosoma congrua sequestration varied with diet and ranged from approximately 3 to 6% dry weight. PMID:20809144

Lampert, Evan C; Bowers, M Deane

2010-08-31

196

Flavonoid glycosides isolated from Salicornia herbacea inhibit matrix metalloproteinase in HT1080 cells.  

PubMed

Flavonoid glycosides, isorhamnetin 3-capital O, Cyrillic-beta-d-glucoside, and quercetin 3-O-beta-d-glucoside were isolated from Salicornia herbacea and their inhibitory effects on matrix metalloproteinase-9 and -2 (MMP-9 and -2) were evaluated in human fibrosarcoma cell line (HT1080). In zymography experiments, these flavonoid glycosides led to the reduction of the expression levels and activities of MMP-9 and -2 without any significant difference between these flavonoid glycosides. Protein expression levels of both MMP-9 and MMP-2 were inhibited and TIMP-1 (tissue inhibitor of metalloproteinase-1) protein level was enhanced by these flavonoid glycosides. Moreover, a transfection study carried out with AP-1 reporter construct revealed that the reporter activity was suppressed by treatment with isorhamnetin 3-capital O, Cyrillic-beta-d-glucoside. Therefore, these results suggested that these flavonoid glycosides have a potential as valuable natural chemopreventive agents for cancer. PMID:18715546

Kong, Chang-Suk; Kim, You Ah; Kim, Moon-Moo; Park, Jin-Sook; Kim, Jung-Ae; Kim, Se-Kwon; Lee, Burm-Jong; Nam, Taek Jeong; Seo, Youngwan

2008-07-31

197

Isolation and hydroxylysine glycoside content of some cyanogen bromide-cleaved fragments of collagen from bovine corneal stroma.  

PubMed Central

Six CNBr-cleaved fragments of insoluble collagen from bovine cornea were isolated, characterized and examined for hydroxylysine glycosides. Thus the general distribution of most of the glycoside along the collagen molecule was determined. Collagen from bovine stroma is almost entirely type I. This work forms a basis for the pinpointing of glycoside-attachment sites along the collagen molecules of bovine cornea.

Panjwani, N A; Harding, J J

1978-01-01

198

Acylated-oxypregnane glycosides from the roots of Araujia sericifera.  

PubMed

Twenty-three new acylated-oxypregnane glycosides were obtained from the roots of Araujia sericifera. (Asclepiadaceae). These glycosides were confirmed to be tetraglycosides possessing twelve known compounds, 12-O-benzoyllineolon, 12-O-benzoyldeacylmetaplexigenin, ikemagenin, kidjolanin, cynanchogenin, caudatin, rostratamine, penupogenin, 12-O-benzoylisolineolon, 12-O-tigloyldecylmetaplexigenin (incisagenin), 12-O-benzoyl-20-O-acetylsarcostin, 20-O-benzoyl-12-O-(E)-cinnamoyl-3 beta,5 alpha,8 beta,12 beta,14 beta,17 beta,20-heptahydroxy-(20S)-pregn-6-ene and ten new acylated-oxypregnanes, 12-O-benzoyl-20S-hydroxyisolineolon, 12-O-tigloyllineolon, 12-O-salicyloyllineolon, 12-O-salicyloyldeacylmetplexigenin, 12-O-benzoyl-3 beta,5 alpha,8 beta,12 beta,14 beta,17 beta-hexahydroxypregn-6-en-20-one, 12-O-benzoyl-19-benzoyloxydeacylmetapleligenin, 12-O-benzoyl-19-benzoyloxy-20-O-acetylsarcostin, 12-O-benzoyl-19-salicyloyloxy-20-O-acetylsarcostin, 12-O-benzoyl-5 alpha,6 alpha-epoxydeacylmetaplexigenin, and 12-O-benzoyl-5 alpha,6 alpha-epoxylineolon as their aglycones, using both spectroscopic and chemical methods. PMID:12951444

Warashina, Tsutomu; Noro, Tadakata

2003-09-01

199

Prenylflavonol, acylated flavonol glycosides and related compounds from Epimedium sagittatum.  

PubMed

Chemical examination of the n-BuOH extract from the aerial parts of Epimedium sagittatum led to isolation of three prenylated flavonol glycosides sagittasine A-C, two acylated flavonol glycosides kaempferol-3-O-(2''-E-p-coumaroyl,4''-Z-p-coumaroyl)-alpha-l-rhamnopyranoside and kaempferol-3-O-(3''-Z-p-coumaroyl,4''-E-p-coumaroyl)-alpha-l-rhamnopyranoside, together with known flavonoids, flavonolignans, 2-phenoxychromones, a lignan, and aromatic acid derivatives. Flavonolignans were identified for the first time in this plant. The vasorelaxing properties of the n-BuOH extract of E. sagittatum and 13 isolated compounds were tested using pre-contracted rat aorta rings in an organ bath apparatus. The results indicated that the n-BuOH extract of E. sagittatum produced a partial endothelial nitric oxide-dependent vasorelaxation, with EC(50) of 0.16+/-0.03 mg/ml. However, the 13 compounds tested, generated only a mild or moderate relaxation, and did not possess significant vasorelaxing effect individually. PMID:17618659

Wang, Guei-Jane; Tsai, Tung-Hu; Lin, Lie-Chwen

2007-07-05

200

Allosteric indicator displacement enzyme assay for a cyanogenic glycoside.  

PubMed

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 ?-glucosidase and a boronic acid appended viologen together with a fluorescent reporter dye. ?-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 ?-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. PMID:24123550

Jose, D Amilan; Elstner, Martin; Schiller, Alexander

2013-10-07

201

Separation of Phenylpropanoid Glycosides from a Chinese Herb by HSCCC.  

PubMed

An effective high-speed counter-current chromatography method was established for the preparative isolation and purification of two phenylpropanoid glycosides from the Tibetan medicinal plant Pedicularis longiflora Rudolph. var. tubiformis (Klotz). Tsoong. With a two-phase solvent system composed of chloroform-n-butanol-methanol-water (4:3:4:5, v/v), 40 mg of an extract of Pedicularis longiflora Rudolph. var. tubiformis (Klotz). Tsoong was separated to yield 20 mg of verbascoside and 18 mg of isoacteoside, with purity values of 97 and 98%, respectively. The chemical structures of these two components were identified by proton and carbon nuclear magnetic resonance. In addition, the antioxidant activity of the two phenylpropanoid glycosides was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH)-high-performance liquid chromatography, and the results showed that the two components exhibited strong antioxidant DPPH radical scavenging activity, with IC50 values of 15.6 and 18.9 µg/mL, respectively. PMID:23680899

Chen, Chen; Zhao, Xiao-Hui; Yue, Hui-Lan; Li, Yu-Lin; Chen, Tao

2013-05-16

202

DFT analysis of NMR scalar interactions across the glycosidic bond in DNA.  

PubMed

The relationship between the glycosidic torsion angle chi, the three-bond couplings (3)J(C2/4-H1') and (3)J(C6/8-H1'), and the one-bond coupling (1)J(C1'-H1') in deoxyribonucleosides and a number of uracil cyclo-nucleosides has been analyzed using density functional theory. The influence of the sugar pucker and the hydroxymethyl conformation has also been considered. The parameters of the Karplus relationships between the three-bond couplings and chi depend strongly on the aromatic base. (3)J(C2/4-H1') reveals different behavior for deoxyadenosine, deoxyguanosine, and deoxycytidine as compared to deoxythymidine and deoxyuridine. In the case of (3)J(C6/8-H1'), an opposite trans to cis ratio of couplings is obtained for pyrimidine nucleosides in contrast to purine nucleosides. The extremes of the Karplus curves are shifted by ca. 10 degrees with respect to syn and anti-periplanar orientations of the coupled nuclei. The change in the sugar pucker from S to N decreases (3)J(C2/4-H1') and (3)J(C6/8-H1'), while increasing (1)J(C1'-H1') for the syn rotamers, whereas all of the trends are reversed for the anti rotamers. The influence of the sugar pucker on (1)J(C1'-H1') is interpreted in terms of interactions between the n(O4'), sigma*(C1'-H1') orbitals. The (1)J(C1'-H1') are related to chi through a generalized Karplus relationship, which combines cos(chi) and cos(2)(chi) functions with mutually different phase shifts that implicitly accounts for a significant portion of the related sugar pucker effects. Most of theoretical (3)J(C2/4-H1') and (3)J(C6/8-H1') for uracil cyclo-nucleosides compare well with available experimental data. (3)J(C6/8-H1') couplings for all C2-bridged nucleosides are up to 3 Hz smaller than in the genuine nucleosides with the corresponding chi, revealing a nonlocal aspect of the spin-spin interactions across the glycosidic bond. Theoretical (1)J(C1'-H1') are underestimated with respect to the experiment by ca. 10% but reproduce the trends in (1)J(C1'-H1') vs chi. PMID:12643728

Munzarová, Markéta L; Sklenár, Vladimír

2003-03-26

203

[Application of nuclear magnetic resonance to the determination of the configuration of glycoside bond].  

PubMed

In the structural determination of natural glycosides, nuclear magnetic resonance (NMR) is an important approach in determining the configuration of glycoside bond. The test of coupling constant of the anomeric proton and chemical shift of the anomeric carbon are two common methods, but these methods are not suitable for some sugars. For those sugars, detailed 13C NMR analysis is an alternative choice. This paper summarizes the characteristics of 1H and 13C NMR data of the common monosaccharides published in the literatures, in order to search an approach to determine the configuration of glycoside bond. PMID:21542281

Pei, Yue-hu; Hua, Hui-ming; Li, Zhan-lin; Chen, Gang

2011-02-01

204

Carijoside A, a Bioactive Sterol Glycoside from an Octocoral Carijoa sp. (Clavulariidae)  

PubMed Central

A new bioactive sterol glycoside, 3?-O-(3?,4?-di-O-acetyl-?-d-arabinopyranosyl) -25?-cholestane-3?,5?,6?,26-tetrol-26-acetate) (carijoside A, 1), was isolated from an octocoral identified as Carijoa sp. The structure of glycoside 1 was established by spectroscopic methods and by comparison with spectral data for the other known glycosides. Carijoside A (1) displayed significant inhibitory effects on superoxide anion generation and elastase release by human neutrophils and this compound exhibited moderate cytotoxicity toward DLD-1, P388D1, HL-60, and CCRF-CEM tumor cells.

Liu, Chih-Yang; Hwang, Tsong-Long; Lin, Mei-Ru; Chen, Yung-Husan; Chang, Yu-Chia; Fang, Lee-Shing; Wang, Wei-Hsien; Wu, Yang-Chang; Sung, Ping-Jyun

2010-01-01

205

Carijoside A, a bioactive sterol glycoside from an octocoral Carijoa sp. (Clavulariidae).  

PubMed

A new bioactive sterol glycoside, 3beta-O-(3',4'-di-O-acetyl-beta-D-arabinopyranosyl)-25xi-cholestane-3beta,5alpha,6beta,26-tetrol-26-acetate) (carijoside A, 1), was isolated from an octocoral identified as Carijoa sp. The structure of glycoside 1 was established by spectroscopic methods and by comparison with spectral data for the other known glycosides. Carijoside A (1) displayed significant inhibitory effects on superoxide anion generation and elastase release by human neutrophils and this compound exhibited moderate cytotoxicity toward DLD-1, P388D1, HL-60, and CCRF-CEM tumor cells. PMID:20714421

Liu, Chih-Yang; Hwang, Tsong-Long; Lin, Mei-Ru; Chen, Yung-Husan; Chang, Yu-Chia; Fang, Lee-Shing; Wang, Wei-Hsien; Wu, Yang-Chang; Sung, Ping-Jyun

2010-06-29

206

New cucurbitane triterpenoids and steroidal glycoside from Momordica charantia.  

PubMed

Three new cucurbitane triterpenoids 1-3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R)-n-butanoxy-5 beta,19-epoxycucurbita-6,23-diene-3beta,25-diol 3-O-beta-glucopyranoside (1), 23-O-beta-allopyranosylecucurbita-5,24-dien-7 alpha,3beta,22(R),23(S)-tetraol 3-O-beta-allopyranoside. (2), 23(R),24(S),25-trihydroxycucurbit-5-ene 3-O-{[beta-glucopyranosyl(1-->6)]-O-beta-glucopyranosyl}-25-O-beta-glucopyranoside (3), and 24(R)-stigmastan-3beta,5 alpha,6 beta-triol-25-ene 3-O-beta-glucopyranoside (4), respectively. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments and chemical reactions. PMID:20032860

Liu, Jie-Qing; Chen, Jian-Chao; Wang, Cui-Fang; Qiu, Ming-Hua

2009-11-25

207

Flavonoid Glycosides from the Seeds of Litchi chinensis.  

PubMed

Seven flavonoid glycosides, including one new (1) and five previously uncharacterized (3-7), were obtained from the seeds of lychee ( Litchi chinensis Sonn. cv. Heiye) by means of repetitive column chromatography and high-performance liquid chromatography (HPLC) preparation. They were identified as litchioside D (1), (-)-pinocembrin 7-O-neohesperidoside (2), (-)-pinocembrin 7-O-rutinoside (3), taxifolin 4'-O-?-d-glucopyranoside (4), kaempferol 7-O-neohesperidoside (5), tamarixetin 3-O-rutinoside (6), and phlorizin (7) on the basis of spectroscopic analysis and comparison of their data to the values reported in the literatures. Among them, compounds 1, 4, and 5 showed in vitro antitumor activity against A549, LAC, Hep-G2, and HeLa cell lines in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. PMID:21287989

Xu, Xinya; Xie, Haihui; Hao, Jing; Jiang, Yueming; Wei, Xiaoyi

2011-02-02

208

[Steroid furostanol glycosides: a new class of natural adaptogenes (review)].  

PubMed

The present review summarizes experimental data revealed while studying the mechanism of the adaptogenic effect of furostanol glycosides (FG) extracted from Dioscorea deltoidea Wall cell culture under the conditions of biotic stress in tomato plants Lycopersicon esculenium Mill. induced by the gall nematode Meloidogyne incognita Kofoid et White. Comparison of changes in isoprene content (phytosterines, tomatin, and carotenoids) and in the rate of oxidative processes in the leaves and roots of intact and treated plants evidence that FG cause nonspecific defense reactions resulting in the formation of systemic acquired resistance. This formation is presented by the enhancement in photosynthetic apparatus pigment fund, pigments of the violaxanthin cycle in particular, by activation of processes related to POL, and by increase in peroxidase activity-enzyme of antioxidant protection. PMID:19845281

Vasil'eva, I S; Udalova, Zh V; Zinov'eva, S V; Paseshnichenko, V A

209

Acetylated flavonoid glycosides potentiating NGF action from Scoparia dulcis.  

PubMed

Three new acetylated flavonoid glycosides, 5,6,4'-trihydroxyflavone 7-O-alpha-L-2,3-di-O-acetylrhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (1), apigenin 7-O-alpha-L-3-O-acetylrhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (2), and apigenin 7-O-alpha-L-2,3-di-O-acetylrhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (3), were isolated from Scoparia dulcis together with the known compound eugenyl beta-D-glucopyranoside (4). Their structures were elucidated by spectroscopic analyses. Compounds 2 and 3 showed an enhancing activity of nerve growth factor-mediated neurite outgrowth in PC12D cells. PMID:15104516

Li, Yushan; Chen, Xigui; Satake, Masayuki; Oshima, Yasukatsu; Ohizumi, Yasushi

2004-04-01

210

Two new flavonol glycosides as DNA topoisomerase I poisons.  

PubMed

Flavonoids are secondary plant metabolites whose anticancer properties are actually being studied from an epidemiological and pharmacological point of view. They are believed to be implicated in the lower risk of some forms of cancer observed in Asian countries, due to their capacity to control cell proliferation, to act on certain regulatory enzymes as protein kinases or topoisomerases. Based on these precedents, three flavonols isolated from a cytotoxic butanol extract from Retama sphaerocarpa Boissier have been assessed to study their topoisomerase I and II activity. Two new rhamnazin glycosides were found to have the ability to stabilize the cleavage complex human DNA topoisomerase I at concentrations in the 100-250 microM range, acting as topoisomersase I poisons. PMID:11204193

López-Lázaro, M; Martín-Cordero, C; Ayuso, M J

211

Antiallergic effect of flavonoid glycosides obtained from Mentha piperita L.  

PubMed

Six flavonoid glycosides, eriocitrin (1), narirutin (2), hesperidin (3), luteolin-7-O-rutinoside (4), isorhoifolin (5), diosmin (6), rosmarinic acid (7) and 5,7-dihydroxycromone-7-O-rutinoside (8), were isolated from the aerial part of Mentha piperita L. Among these compounds, compound 4 showed a potent inhibitory effect on histamine release induced by compound 48/80 and antigen-antibody reaction. This compound was more effective than luteolin and luteolin-7-O-glucoside in inhibiting histamine release from rat peritoneal mast cells. Compound 4 also caused a dose-related inhibition of the antigen-induced nasal response and significant effects were observed at doses of 100 and 300 mg/kg. These results indicate that compound 4 may be clinically useful in alleviating the nasal symptoms of allergic rhinitis. PMID:11853178

Inoue, Toshio; Sugimoto, Yukio; Masuda, Hideki; Kamei, Chiaki

2002-02-01

212

Synthesis of C-cinnamoyl glycosides and their inhibitory activity against mammalian carbonic anhydrases.  

PubMed

A small series of C-cinnamoyl glycosides incorporating the phenol moiety has been prepared by reaction of glycosyl ketones with the appropriate benzaldehydes. Glycosides were tested for the inhibition of twelve mammalian isoforms of carbonic anhydrase. This is the first study in which ?-CAs have been investigated for their interaction with C-glycosides, a novel carbohydrate scaffold in the design of carbonic anhydrase inhibitors. The C-cinnamoyl glycosides were generally effective CA inhibitors, with inhibition constants in the low micromolar range against CA I, II, IV, VA, VB, VI, VII, IX, XII, XIII, XIV and ineffective inhibitors of CA III. These results confirm that attaching carbohydrate moieties to CA phenol pharmacophore improves its inhibitory activity. PMID:23010455

Riafrecha, Leonardo E; Rodríguez, Oscar M; Vullo, Daniela; Supuran, Claudiu T; Colinas, Pedro A

2012-09-11

213

Enzyme-catalyzed synthesis of heptyl-?-glycosides: Effect of water coalescence at high temperature.  

PubMed

Alkyl glycosides can be synthesized by glycosidases in organic media with limited amounts of water. These systems, however, limit the solubility of the sugar substrates and decrease reaction yields. Herein we report the enzymatic synthesis of heptyl-?-glycosides in heptanol catalyzed by a hyperthermophilic ?-glycosidase at 90°C. Our results indicate that dispersion of water in heptanol changes with time producing coalescence of water at the bottom of the reactor, playing a key role in the reaction yield. Water-soluble substrate, enzyme and products are concentrated in the aqueous phase, according to their partition coefficients, promoting side reactions that inactivate the enzyme. Reaction yield of heptyl-?-glycosides was 35% relative to lactose, at 7% water. The increase in the water phase to 12% diminished the enzyme inactivation and increased the heptyl-?-glycosides yield to 52%. Surface-active compounds, SDS and octyl glucoside, increased water dispersion but were unable to prevent coalescence. PMID:23863873

Montiel, Carmina; Bustos-Jaimes, Ismael; Bárzana, Eduardo

2013-06-28

214

Synthesis of carboranyl derivatives of alkynyl glycosides as potential BNCT agents  

Microsoft Academic Search

A series of amphiphilic carbohydrate-carborane hybrids consisting of a lipophilic core (carborane cage) and a glycoside moiety for conferring high-affinity recognition by the cellular lectins have been prepared in a chemically accessible fashion.

Giovanni Battista Giovenzana; Luigi Lay; Diego Monti; Giovanni Palmisano; Luigi Panza

1999-01-01

215

Solubility enhancement of steviol glycosides and characterization of their inclusion complexes with gamma-cyclodextrin.  

PubMed

Steviol glycosidesrebaudioside (reb) A, C and D have low aqueous solubilities. To improve their aqueous solubilities, inclusion complex of steviol glycosides, reb A, C and D and gamma cyclodextrin were prepared by freeze drying method and further characterized by means of differential scanning calorimetry, Fourier transform infrared spectroscopy and Raman spectroscopy. The effect of gamma cyclodextrin on chemical shifts of the steviol glycosides was also studied in proton NMR experiments as well as in solid state (13)C CP/MAS NMR experiments. These results indicated that the steviol glycosides were clearly in inclusion complex formation with the gamma cyclodextrin which also results in solubility enhancement of these steviol glycosides. Phase solubility studies showed that amounts of soluble reb A, C and D increased with increasing amounts of gamma cyclodextrin indicating formation of 1:1 stoichiometric and higher order inclusion complexes. PMID:22174615

Upreti, Mani; Strassburger, Ken; Chen, You L; Wu, Shaoxiong; Prakash, Indra

2011-11-03

216

Stability evaluation of selected polyphenols and triterpene glycosides in black cohosh.  

PubMed

Black cohosh ( Actaea racemosa L., syn. Cimicifuga racemosa L.) is rich in both triterpene glycosides and polyphenols, which have various biological activities that may be important to its medical use. To evaluate the stability of the polyphenolic constituents and triterpene glycosides of black cohosh, experiments were conducted using three sample types: plant material, extracts of black cohosh, and encapsulated commercial extract. The samples were stored at various temperatures and humidity conditions. Three triterpene glycosides and six major polyphenols in black cohosh were quantitatively measured with an HPLC-PDA method at 0, 3, 6, and 9 weeks. The triterpene glycosides were stable at the tested conditions, whereas the polyphenols were stable only at room temperature and low humidity and not stable at higher temperature and/or humidity due to hydrolysis and/or oxidation. The rate of compound decomposition depended upon the chemical structure of the individual polyphenols. Polyphenols in the extracts decomposed more readily than those in plant material. PMID:18817410

Jiang, Bei; Lyles, James T; Reynertson, Kurt A; Kronenberg, Fredi; Kennelly, Edward J

2008-09-26

217

Synthesis and antiproliferative activity of selenoindirubins and selenoindirubin-N-glycosides.  

PubMed

Selenoindirubins and selenoindirubin-N-glycosides were prepared by the reaction of isatins and isatin-N-glycosides with 3-acetoxy-benzo[b]selenophene, respectively. While selenoindirubin-N-glycosides have not been reported before, three non-glycosylated selenoindirubins were previously reported, but without quantities, yields, scales, experimental details and spectroscopic data. In addition, the work could, in our hands, not be reproduced to prepare pure products. The present paper includes an optimized procedure for the synthesis of selenoindirubins and their complete characterization. Both selenoindirubins and selenoindirubin-N-glycosides showed antiproliferative activity in lung cancer cell lines. In melanoma cells, antiproliferative effects were further accompanied by induced apoptosis in combination with the death ligand TRAIL. PMID:23673975

Erben, Friedrich; Kleeblatt, Dennis; Sonneck, Marcel; Hein, Martin; Feist, Holger; Fahrenwaldt, Thomas; Fischer, Christine; Matin, Abdul; Iqbal, Jamshed; Plötz, Michael; Eberle, Jürgen; Langer, Peter

2013-06-28

218

Arrhythmogenic adverse effects of cardiac glycosides are mediated by redox modification of ryanodine receptors  

PubMed Central

Abstract The therapeutic use of cardiac glycosides (CGs), agents commonly used in treating heart failure (HF), is limited by arrhythmic toxicity. The adverse effects of CGs have been attributed to excessive accumulation of intracellular Ca2+ resulting from inhibition of Na+/K+-ATPase ion transport activity. However, CGs are also known to increase intracellular reactive oxygen species (ROS), which could contribute to arrhythmogenesis through redox modification of cardiac ryanodine receptors (RyR2s). Here we sought to determine whether modification of RyR2s by ROS contributes to CG-dependent arrhythmogenesis and examine the relevant sources of ROS. In isolated rat ventricular myocytes, the CG digitoxin (DGT) increased the incidence of arrhythmogenic spontaneous Ca2+ waves, decreased the sarcoplasmic reticulum (SR) Ca2+ load, and increased both ROS and RyR2 thiol oxidation. Additionally, pretreatment with DGT increased spark frequency in permeabilized myocytes. These effects on Ca2+ waves and sparks were prevented by the antioxidant N-(2-mercaptopropionyl) glycine (MPG). The CG-dependent increases in ROS, RyR2 oxidation and arrhythmogenic propensity were reversed by inhibitors of NADPH oxidase, mitochondrial ATP-dependent K+ channels (mito-KATP) or permeability transition pore (PTP), but not by inhibition of xanthine oxidase. These results suggest that the arrhythmogenic adverse effects of CGs involve alterations in RyR2 function caused by oxidative changes in the channel structure by ROS. These CG-dependent effects probably involve release of ROS from mitochondria possibly mediated by NADPH oxidase.

Ho, Hsiang-Ting; Stevens, Sarah C W; Terentyeva, Radmila; Carnes, Cynthia A; Terentyev, Dmitry; Gyorke, Sandor

2011-01-01

219

Analytical Procedures for Determination of Quercetin and its Glycosides in Plant Material  

Microsoft Academic Search

Quercetin and its glycosides are widely distributed in the plant kingdom and belong to the most abundant of the flavonoid molecules. Besides their important biological roles in plant pigmentation, these flavonols possess anti-cancer and anti-inflammatory properties, which are the consequence of their affinity for proteins and their anti-oxidant properties. The content of quercetin and its glycosides in different plants have

Magdalena Biesaga; Krystyna Pyrzynska

2009-01-01

220

Kaempferol 3,7,4'-glycosides from the flowers of Clematis cultivars.  

PubMed

A new kaempferol glycoside, kaempferol 3-O-alpha-rhamnopyranosyl-(1 --> 6)-beta-glucopyranoside-7,4'-di-O-beta-glucopyranoside (1) was isolated from the flowers of Clematis cultivars "Jackmanii Superba" and "Fujimusume", together with the known compound kaempferol 3,7,4'-tri-O-beta-glucopyranoside (2). The chemical structures of the isolated kaemferol glycosides were established by UV, 1H and 13C NMR spectroscopy, LC-MS, and characterization of acid hydrolysates. PMID:24079175

Sakaguchi, Keisuke; Kitajima, Junichi; Iwashina, Tsukasa

2013-08-01

221

Cholestane and pregnane-type glycosides from the roots of Tribulus cistoides  

Microsoft Academic Search

From the methanolic extract of the roots of Tribulus cistoides the cardioactive saponin-3, which is known to occur in the leaves, was isolated along with tribulosin, a pregnane-type glycoside and eight new cholestane glycosides. d-(+)-Pinitol and sucrose were major constituents. The structures were established by spectroscopic studies of the isolated compounds, their acetylated derivatives and their hydrolysation products. Chemical conversions

Hans Achenbach; Harald Hübner; Melchior Reiter

1996-01-01

222

Deglycosylation of flavonoid and isoflavonoid glycosides by human small intestine and liver ?-glucosidase activity  

Microsoft Academic Search

Flavonoid and isoflavonoid glycosides are common dietary phenolics which may be absorbed from the small intestine of humans. The ability of cell-free extracts from human small intestine and liver to deglycosylate various (iso)flavonoid glycosides was investigated. Quercetin 4?-glucoside, naringenin 7-glucoside, apigenin 7-glucoside, genistein 7-glucoside and daidzein 7-glucoside were rapidly deglycosylated by both tissue extracts, whereas quercetin 3,4?-diglucoside, quercetin 3-glucoside, kaempferol

Andrea J Day; M. Susan DuPont; Saxon Ridley; Mike Rhodes; Michael J. C Rhodes; Michael R. A Morgan; Gary Williamson

1998-01-01

223

Effect of phytotoxic resin glycoside on activity of H + ATPase from plasma membrane  

Microsoft Academic Search

A resin glycoside mixture isolated fromIpomoea tricolor inhibited radicle growth ofEchinochloa crusgalli. The effect of the resin was tested on the activity of the plasma membrane H+-ATPase fromE. crusgalli. For this purpose, plasma membrane vesicles were purified by the method of aqueous two-phase partitioning. The resin glycoside inhibited by 30% the activity of the plasma membrane ATPase. The same result

M. R. Calera; A. L. Anaya; M. Gavilanes-Ruiz

1995-01-01

224

A flavonol glycoside-lignan ester and accompanying acylated glucosides from Monochaetum multiflorum.  

PubMed

Four acylated glycosides along with six known glycosides were isolated from the leaves of Monochaetum multiflorum. The new compounds were characterized as 4-O-(6'-O-galloyl-beta-glucopyranosyl)-cis-p-coumaric acid, 6'-O-galloylprunasin, benzyl 6'-O-galloyl-beta-glucopyranoside, and a novel diester of tetrahydroxy-mu-truxinic acid with 2 mol of hyperin (monochaetin), based on NMR and MS spectral data and chemical evidence. PMID:11551558

Isaza, J H; Ito, H; Yoshida, T

2001-09-01

225

A flavonol glycoside-lignan ester and accompanying acylated glucosides from Monochaetum multiflorum  

Microsoft Academic Search

Four acylated glycosides along with six known glycosides were isolated from the leaves of Monochaetum multiflorum. The new compounds were characterized as 4-O-(6?-O-galloyl-?-glucopyranosyl)-cis-p-coumaric acid, 6?-O-galloylprunasin, benzyl 6?-O-galloyl-?-glucopyranoside, and a novel diester of tetrahydroxy-?-truxinic acid with 2 mol of hyperin (monochaetin), based on NMR and MS spectral data and chemical evidence.

Jose H Isaza; Hideyuki Ito; Takashi Yoshida

2001-01-01

226

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

Microsoft Academic Search

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)-?-glucopyranosyl-(1?2)-?-glucopyranosyl-7-O-?-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

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

2006-01-01

227

Crystal Structure of ?- d-Xylosidase from Thermoanaerobacterium saccharolyticum, a Family 39 Glycoside Hydrolase  

Microsoft Academic Search

1,4-?-d-Xylan is the major component of plant cell-wall hemicelluloses. ?-d-Xylosidases are involved in the breakdown of xylans into xylose and belong to families 3, 39, 43, 52, and 54 of glycoside hydrolases. Here, we report the first crystal structure of a member of family 39 glycoside hydrolase, i.e. ?-d-xylosidase from Thermoanaerobacterium saccharolyticum strain B6A-RI. This study also represents the first

Jin Kuk Yang; Hye-Jin Yoon; Hyung Jun Ahn; Byung Il Lee; Jean-Denis Pedelacq; Elaine C. Liong; Joel Berendzen; Maris Laivenieks; Claire Vieille; Gregory J. Zeikus; David J. Vocadlo; Stephen G. Withers; Se Won Suh

2004-01-01

228

Isolation, characterization, and surfactant properties of the major triterpenoid glycosides from unripe tomato fruits.  

PubMed

Various triterpenoid glycosides were extracted from whole unripe tomato fruits ( Lycopersicon esculentum cv. Cedrico), using aqueous 70% (v/v) ethanol to study their surfactant properties. Cation-exchange chromatography using a Source 15S column and subsequent semipreparative HPLC using an XTerra RP18 were employed to purify individual triterpenoid glycosides from the extract. The structure of the purified compounds was established by mass spectrometry and nuclear magnetic resonance spectroscopy. The furostanol glycoside tomatoside A (749 mg/kg of DW) and the glycoalkaloids alpha-tomatine (196 mg/kg of DW) and esculeoside A (427 mg/kg of DW) were the major triterpenoid glycosides present. Furthermore, minor amounts of a new dehydrofurostanol glycoside, dehydrotomatoside, were found. The critical micelle concentrations of the major triterpenoid glycosides, alpha-tomatine, tomatoside A, and esculeoside A, were determined as 0.099, 0.144, and 0.412 g/L, respectively. The results show that tomatoside A, and not the more well-known alpha-tomatine, is the predominant triterpenoidal surfactant in unripe tomato fruits. PMID:18998702

Yamanaka, Takao; Vincken, Jean-Paul; de Waard, Pieter; Sanders, Mark; Takada, Norihisa; Gruppen, Harry

2008-12-10

229

Comparison of three thermostable ?-glucosidases for application in the hydrolysis of soybean isoflavone glycosides.  

PubMed

A novel thermostable ?-glucosidase (Te-BglA) from Thermoanaerobacter ethanolicus JW200 was cloned, characterized and compared for its activity against isoflavone glycosides with two ?-glucosidases (Tm-BglA, Tm-BglB) from Thermotoga maritima. Te-BglA exhibited maximum hydrolytic activity toward pNP-?-d-glucopyranoside (pNPG) at 80 °C and pH 7.0, was stable for a pH range of 4.6-7.8 and at 65 °C for 3 h, and had the lowest K(m) for the natural glycoside salicin and the highest relative substrate specificity (k(cat)/K(m))((salicin))/(k(cat)/K(m))((pNPG)) among the three enzymes. It converted isoflavone glycosides, including malonyl glycosides, in soybean flour to their aglycons more efficiently than Tm-BglA and Tm-BglB. After 3 h of incubation at 65 °C, Te-BglA produced complete hydrolysis of four isoflavone glycosides (namely, daidzin, genistin and their malonylated forms), exhibiting higher productivity of genistein and daidzein than the other two ?-glucosidases. Our results suggest that Te-BglA is preferable to Tm-BglA and Tm-BglB, but all three enzymes have great potential applications in converting isoflavone glycosides into their aglycons. PMID:21294581

Song, Xiangfei; Xue, Yemin; Wang, Qilei; Wu, Xixi

2011-02-02

230

CHARMM Additive All-Atom Force Field for Glycosidic Linkages between Hexopyranoses.  

PubMed

We present an extension of the CHARMM hexopyranose monosaccharide additive all-atom force field to enable modeling of glycosidic-linked hexopyranose polysaccharides. The new force field parameters encompass 1?1, 1?2, 1?3, 1?4, and 1?6 hexopyranose glycosidic linkages, as well as O-methylation at the C(1) anomeric carbon, and are developed to be consistent with the CHARMM all-atom biomolecular force fields for proteins, nucleic acids, and lipids. The parameters are developed in a hierarchical fashion using model compounds containing the key atoms in the full carbohydrates, in particular O-methyl-tetrahydropyran and glycosidic-linked dimers consisting of two molecules of tetrahyropyran or one of tetrahydropyran and one of cyclohexane. Target data for parameter optimization include full two-dimensional energy surfaces defined by the ?/? glycosidic dihedral angles in the disaccharide analogs as determined by quantum mechanical MP2/cc-pVTZ single point energies on MP2/6-31G(d) optimized structures (MP2/cc-pVTZ//MP2/6-31G(d)). In order to achieve balanced, transferable dihedral parameters for the ?/? glycosidic dihedral angles, surfaces for all possible chiralities at the ring carbon atoms involved in the glycosidic linkages are considered, resulting in over 5000 MP2/cc-pVTZ//MP2/6-31G(d) conformational energies. Also included as target data are vibrational frequencies, pair interaction energies and distances with water molecules, and intramolecular geometries including distortion of the glycosidic valence angle as a function of the glycosidic dihedral angles. The model-compound optimized force field parameters are validated on full disaccharides through comparison of molecular dynamics results to available experimental data. Good agreement is achieved with experiment for a variety of properties including crystal cell parameters and intramolecular geometries, aqueous densities, and aqueous NMR coupling constants associated with the glycosidic linkage. The newly-developed parameters allow for the modeling of linear, branched, and cyclic hexopyranose glycosides both alone and in heterogenous systems including proteins, nucleic acids and/or lipids when combined with existing CHARMM biomolecular force fields. PMID:20161005

Guvench, Olgun; Hatcher, Elizabeth R; Venable, Richard M; Pastor, Richard W; Mackerell, Alexander D

2009-08-20

231

O-Glycosidation reactions promoted by in situ generated silver N-heterocyclic carbenes in ionic liquids  

Microsoft Academic Search

We herein report O-glycosidation reactions promoted via silver N-heterocyclic carbene complexes formed in situ in ionic liquids. Seven different room temperature ionic liquids were screened for the glycosidation reaction of 4-nitrophenol with tetra-O-acetyl-?-d-galactopyranosyl bromide. Good to excellent yields were obtained using Ag–NHC complexes derived from imidazolium halide salts to promote the glycosidation reaction, whereas yields considered moderate to low were

Ian Jamie Talisman; Vineet Kumar; Jacqueline Razzaghy; Sanjay V. Malhotra

2011-01-01

232

Reverse Correlation in Neurophysiology  

ERIC Educational Resources Information Center

This article presents a review of reverse correlation in neurophysiology. We discuss the basis of reverse correlation in linear transducers and in spiking neurons. The application of reverse correlation to measure the receptive fields of visual neurons using white noise and m-sequences, and classical findings about spatial and color processing in…

Ringach, Dario; Shapley, Robert

2004-01-01

233

Ultrasonic Time Reversal Mirrors  

Microsoft Academic Search

For more than ten years, time reversal techniques have been developed in many different fields of applications including detection of defects in solids, underwater acoustics, room acoustics and also ultrasound medical imaging and therapy. The essential property that makes time reversed acoustics possible is that the underlying physical process of wave propagation would be unchanged if time were reversed. In

Mathias Fink; Gabriel Montaldo; Mickael Tanter

2004-01-01

234

Reverse Correlation in Neurophysiology  

ERIC Educational Resources Information Center

|This article presents a review of reverse correlation in neurophysiology. We discuss the basis of reverse correlation in linear transducers and in spiking neurons. The application of reverse correlation to measure the receptive fields of visual neurons using white noise and m-sequences, and classical findings about spatial and color processing in…

Ringach, Dario; Shapley, Robert

2004-01-01

235

Structure and cytotoxicity of steroidal glycosides from Allium schoenoprasum.  

PubMed

A phytochemical analysis of the whole plant of Allium schoenoprasum, has led to the isolation of four spirostane-type glycosides (1-4), and four known steroidal saponins. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as (20S,25S)-spirost-5-en-3?,12?,21-triol 3-O-?-L-rhamnopyranosyl-(1?2)-?-D-glucopyranoside (1), (20S,25S)-spirost-5-en-3?,11?,21-triol 3-O-?-L-rhamnopyranosyl-(1?2)-?-D-glucopyranoside (2), laxogenin 3-O-?-L-rhamnopyranosyl-(1?2)-[?-D-glucopyranosyl-(1?4)]-?-D-glucopyranoside (3), and (25R)-5?-spirostan-3?,11?-diol 3-O-?-D-glucopyranosyl-(1?3)-[?-D-glucopyranosyl-(1?4)]-?-D-galactopyranoside (4). Four of the isolated compounds were tested for cytotoxic activity against the HCT 116 and HT-29 human colon cancer cell lines. PMID:23357597

Timité, Gaoussou; Mitaine-Offer, Anne-Claire; Miyamoto, Tomofumi; Tanaka, Chiaki; Mirjolet, Jean-François; Duchamp, Olivier; Lacaille-Dubois, Marie-Aleth

2013-01-25

236

New acylated flavonoid glycosides from flowers of Aerva javanica.  

PubMed

Chromatographic purification of ethyl acetate soluble fraction of the methanolic extract of the flowers of Aerva javanica yielded three new acylated flavone glycosides: kaempferol-3-O-?-d-[4?-E-p-coumaroyl-?-l-rhamnosyl(1 ? 6)]-galactoside (1), kaempferol-3-O-?-d-[4?-E-p-coumaroyl-?-l-rhamnosyl(1 ? 6)]-(3?-E-p-coumaroyl)galactoside (2), and kaempferol-3-O-?-d-[4?-E-p-coumaroyl-?-l-rhamnosyl(1 ? 6)]-(4?-E-p-coumaroyl)galactoside (3), along with p-coumaric acid (4), caffeic acid (5), gallic acid (6), eicosanyl-trans-p-coumarate (7), hexadecyl ferulate (8), and hexacosyl ferulate (9). The compounds 1-9 were characterized using 1D ((1)H, (13)C) and 2D NMR (HMQC, HMBC, and COSY) spectroscopy and mass spectrometry (EI-MS, HR-EI-MS, FAB-MS, and HR-FAB-MS) and in comparison with the reported data in the literature. Compound 1 showed weak inhibitory activity against enzymes, such as acetylcholinesterase, butyrylcholinesterase, and lipoxygenase with IC50 values 205.1, 304.1, and 212.3 ?M, respectively, whereas compounds 2 and 3 were only weakly active against the enzyme acetylcholinesterase. PMID:23768097

Mussadiq, Sara; Riaz, Naheed; Saleem, Muhammad; Ashraf, Muhammad; Ismail, Tayaba; Jabbar, Abdul

2013-06-14

237

A new phenylpropane glycoside from the rhizome of Sparganium stoloniferum.  

PubMed

The purification of the MeOH extract from the rhizome of Sparganium stoloniferum Buch.-Hamil. (Sparganiaceae) using column chromatography furnished one new phenylpropanoid glycoside (7) and known phenolic compounds (1-6, and 8-13). The structural elucidation of 7 was based on 1D- and 2D-NMR spectroscopic data analysis to be beta-D-(6-O-trans-feruloyl) fructofuranosyl-alpha-D-O-glucopyranoside. Compounds 1-6, and 8-13 were elucidated by spectroscopy and confirmed by comparison with reported data; 24-methylenecycloartanol (1), p-hydroxybenzaldehyde (2), ferulic acid (3), p-coumaric acid (4), vanillic acid (5), beta-D-(1-O-acetyl-3-O-trans-feruloyl)fructofuranosy-alpha-D-2',4',6'.-O-triacetyglucopyranoisde (6), beta-D-(1-O-acetyl-3,6-O-trans-diferuloyl)fructofuranosyl-beta-D-2',4',6'.-O-triacetylglucopyranoisde (8), hydroxytyrosol acetate (9), hydroxytyrosol (10), isorhamnetin-3-O-rutinoside (11), n-butyl-alpha-D-fructofuranoside (12), and n-butyl-beta-D-fructopyranoside (13). Compounds 3 and 9-13 were isolated for the first time from this plant. The isolated compounds were tested for cytotoxicity against four human tumor cell lines in vitro using a Sulforhodamin B bioassay. PMID:20422359

Lee, Seung Young; Choi, Sang Un; Lee, Jei Hyun; Lee, Dong Ung; Lee, Kang Ro

2010-04-27

238

Antioxidative iridoid glycosides and phenolic compounds from Veronica peregrina.  

PubMed

Eight iridoid glycosides and four phenolic compounds were isolated from the EtOAc soluble fraction of Veronica peregrina MeOH extract as the radical scavengers for antioxidant activity. The compounds were identified as protocatechuic acid (1), luteolin (2), veronicoside (3), minecoside (4), specioside (5), amphicoside (6), catalposide (7), 6-O-cis-p-coumaroyl catalpol (8), p-hydroxy benzoic acid methyl ester (9), verproside (10), verminoside (11), and chrysoeriol 7-glucuronide (12) by spectroscopic analysis. All compounds except for 1 and 2 were isolated for the first time from this plant. The antioxidant activity was evaluated by the ORAC(Oxygen Radical Absorbance Capacity) assay, which measures scavenging activity against peroxy radicals induced by 2,2'-azobis (2-methoxypropion-amidine) dihydrochloride, and the ORAC value is expressed as relative trolox equivalent. Compounds 2, 4, 5, 6, 8, and 12 exhibited potent antioxidant activity, and compounds 1, 11 had similar activity with trolox, whereas the other compounds showed weaker activity than trolox. PMID:19280150

Kwak, Jong Hwan; Kim, Hyun Jung; Lee, Kwang Ho; Kang, Se Chan; Zee, Ok Pyo

2009-03-13

239

Steryl glycosides: a characteristic feature of the Helicobacter spp.?  

PubMed Central

The lipids of different species of Helicobacter (H.felis, H. muridarum, H. mustelae, H. fennelliae, and H. cinaedi) were studied. Different types of cholesteryl glucosides were found in all of the species studied except H. cinaedi. The total amount of cholesteryl glucosides varied from 14.8% of total lipids in H. mustelae to 33.1% of total lipids in H. felis. The different types of cholesteryl glucosides and their species distribution are cholesteryl-6-O-acyl-alpha-D-glucopyranoside (cholesteryl-6-O-tetradecanoyl-alpha-D-glucopyranoside in H. felis and cholesteryl-6-O-dodecanoyl-alpha-D-glucopyranoside in H. muridarum), cholesteryl-alpha-D-glucopyranoside (H. felis, H. muridarum, H. mustelae, and H. fennelliae), and cholesteryl-6-O-phosphatidyl-alpha-D-glucopyranoside (H. fennelliae). The neutral lipid fractions showed a high percentage of cholesterol, with selective accumulation of free cholesterol. The study thus shows that the characteristic presence of steryl glycosides in Helicobacter spp. may be an important chemotaxonomic marker for many of the species, and the helicobacters show a selective accumulation of free cholesterol from the media.

Haque, M; Hirai, Y; Yokota, K; Oguma, K

1995-01-01

240

Ex Vivo Activity of Cardiac Glycosides in Acute Leukaemia  

PubMed Central

Background Despite years of interest in the anti-cancerous effects of cardiac glycosides (CGs), and numerous studies in vitro and in animals, it has not yet been possible to utilize this potential clinically. Reports have demonstrated promising in vitro effects on different targets as well as a possible therapeutic index/selectivity in vitro and in experimental animals. Recently, however, general inhibition of protein synthesis was suggested as the main mechanism of the anti-cancerous effects of CGs. In addition, evidence of species differences of a magnitude sufficient to explain the results of many studies called for reconsideration of earlier results. Principal Findings In this report we identified primary B-precursor and T-ALL cells as being particularly susceptible to the cytotoxic effects of CGs. Digitoxin appeared most potent and IC50 values for several patient samples were at concentrations that may be achieved in the clinic. Significant protein synthesis inhibition at concentrations corresponding to IC50 was demonstrated in colorectal tumour cell lines moderately resistant to the cytotoxic effects of digoxin and digitoxin, but not in highly sensitive leukaemia cell lines. Conclusion It is suggested that further investigation regarding CGs may be focused on diagnoses like T- and B-precursor ALL.

Hallbook, Helene; Felth, Jenny; Eriksson, Anna; Fryknas, Marten; Bohlin, Lars; Larsson, Rolf; Gullbo, Joachim

2011-01-01

241

Effects of synthetic glycosides on steroid balance in Macaca fascicularis  

SciTech Connect

The predominantly beta-anomer of diosgenin glucoside (DG) was synthesized and its effects on cholesterol homeostasis were tested in monkeys. Cynomolgus macaques (Macaca fascicularis) were fed, during two 3-week periods, a semipurified diet with 0.1% cholesterol and a similar ration containing 1% DG, respectively. A Chow diet was given for 5 weeks between the experimental periods. Cholesterol and bile acid balance were analyzed during the last week of each semipurified diet. Diosgenin glucoside reduced cholesterolemia from 292 mg/dl to 172 mg/dl, decreased intestinal absorption of exogenous cholesterol from 62.4% to 26.0%, and increased secretion of endogenous cholesterol from -0.8 to 93.5 mg/day. The fecal excretion of neutral steroids rose from 40.7 to 157.3 mg/day; that of bile acids changed, nonsignificantly, from 23.1 to 16.0 mg/day. The cholesterol balance was -44 mg/day in the control period, and 88 mg/day in the DG-fed animals. No toxic signs were observed. Thus, when long-term studies demonstrate that the glucoside is well tolerated, DG and other synthetic glycosides with similar activities may be of use in the management of hypercholesterolemia and atherosclerosis.

Malinow, M.R.; Elliott, W.H.; McLaughlin, P.; Upson, B.

1987-01-01

242

Iodine-hexamethyldisilane (HMDS)-mediated anomerization of peracetylated 1,2-trans-linked alkyl and aryl glycosides.  

PubMed

Treatment of peracetylated alkyl and aryl 1,2-trans-glycosides with iodine in the presence of HMDS has been found to result in the anomerization leading to the formation of the respective 1,2-cis-glycosides. In the case of alkyl glycosides with aglycons of short alkyl chain length complete anomerization to the alpha-glycosides was observed while with those of longer chain length the process was found to be incomplete. The observations have been interpreted mechanistically. PMID:20304387

Malik, Satish; Shah, Krupesh J; Ravindranathan Kartha, K P

2010-02-19

243

Cardiac glycosides block cancer growth through HIF-1?- and NF-?B-mediated Plk1.  

PubMed

Cardiac glycosides as inhibitors of the sodium/potassium adenosine triphosphatase (sodium pump) have been reported to block cancer growth by inducing G2/M phase arrest in many cancer cells. However, no detailed studies have been performed to distinguish between these two phases of cardiac glycoside-arrested cells. Furthermore, the underlying mechanisms involved in this cell cycle arrest process are still not known. Here, we report that bufalin and other cardiac glycosides potently induce mitotic arrest by the downregulation of polo-like kinase 1 (Plk1) expression. Live-cell imaging results demonstrate that bufalin-treated cells exhibit a marked delay in entering prophase at an early stage and are then arrested at prometaphase or induced entry into apoptosis. This phenotypic change is attributed to the downregulation of Plk1. We also show that bufalin and the knockdown of sodium pump reduce Plk1, at least in part, through downregulation of the nuclear transcription factors, hypoxia-inducible factor-1? (HIF-1?) and nuclear factor-kappa B (NF-?B). These findings suggest that cardiac glycosides induce mitotic arrest and apoptosis through HIF-1?- and NF-?B-mediated downregulation of Plk1 expression, demonstrating that HIF-1? and NF-?B are critical targets of cardiac glycosides in exerting their anticancer action. PMID:23615397

Xie, Chuan-Ming; Liu, Xiao-Yu; Yu, Sidney; Cheng, Christopher H K

2013-04-24

244

Isolation and identification of some steroidal glycosides of Furcraea selloa.  

PubMed

The antischistosomal impact of different extracts of the leaves of Furcraea selloa C. Koch (Family Agavaceae) were screened against adult Schistosoma mansoni worms in vitro using well established culture media. The methanol extract of the plant showed the highest activity as S. mansoni worms recorded 100% mortality at 50 microg/ml after 24 h (EC50 = 29.78 and 29.41 microg/ml for female and male worm respectively). Owing to the high potency of the crude butanolic extract (100% mortality at 20 microg/ ml; EC50 = 10.42 and 8.94 microg/ml for female and male worm respectively) obtained from the methanolic extract, it was submitted to chromatographic separation and isolation using silica gel and Sephadex columns as well as preparative thin layer chromatography. Three steroidal glycosides (saponins) (I-III) were isolated and their structures were elucidated using some spectroscopic and chemical methods. The structure of the three compounds was formulated as 6-O-beta-glucopyranosyl-(1-->4)-beta-D-glucopyranoside chlorogenin (I), 3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranoside crestagenin (II) and 3-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->3)-beta-D-xylopyranoside gloriogenin (III). Only compound III at 5 micro/ml led to 100% mortality of the S. mansoni (EC50 = 2.25 and 1.91 microg/ml for female and male worm respectively) whereas compounds I and II did not show any activity up to 50 microg/ml. PMID:16724551

El-Sayed, M M; Abdel-Hameed, E S; El-Nahas, H A; El-Wakil, E A

2006-05-01

245

Bioprospecting metagenomics of decaying wood: mining for new glycoside hydrolases  

PubMed Central

Background To efficiently deconstruct recalcitrant plant biomass to fermentable sugars in industrial processes, biocatalysts of higher performance and lower cost are required. The genetic diversity found in the metagenomes of natural microbial biomass decay communities may harbor such enzymes. Our goal was to discover and characterize new glycoside hydrolases (GHases) from microbial biomass decay communities, especially those from unknown or never previously cultivated microorganisms. Results From the metagenome sequences of an anaerobic microbial community actively decaying poplar biomass, we identified approximately 4,000 GHase homologs. Based on homology to GHase families/activities of interest and the quality of the sequences, candidates were selected for full-length cloning and subsequent expression. As an alternative strategy, a metagenome expression library was constructed and screened for GHase activities. These combined efforts resulted in the cloning of four novel GHases that could be successfully expressed in Escherichia coli. Further characterization showed that two enzymes showed significant activity on p-nitrophenyl-?-L-arabinofuranoside, one enzyme had significant activity against p-nitrophenyl-?-D-glucopyranoside, and one enzyme showed significant activity against p-nitrophenyl-?-D-xylopyranoside. Enzymes were also tested in the presence of ionic liquids. Conclusions Metagenomics provides a good resource for mining novel biomass degrading enzymes and for screening of cellulolytic enzyme activities. The four GHases that were cloned may have potential application for deconstruction of biomass pretreated with ionic liquids, as they remain active in the presence of up to 20% ionic liquid (except for 1-ethyl-3-methylimidazolium diethyl phosphate). Alternatively, ionic liquids might be used to immobilize or stabilize these enzymes for minimal solvent processing of biomass.

2011-01-01

246

Reversible metabolism of drugs.  

PubMed

Many drugs undergo reversible metabolism. The basis of our understanding of this process is the reversible metabolism of prednisone (PD)-prednisolone (PL). The pharmacokinetics of reversible metabolism requires the use of four area under the curve values integrated into four equations for clearance (CL). Other variables, such as linear versus non-linear disposition, can play important roles in reversible metabolism. Of recent interest is the reversible metabolism of haloperidol which consists of an interconversion process between the parent drug haloperidol (HL) and its reduced metabolite (RH). However, the interconversion of HL-RH differs from the PD-PL model in that, whereas PD and PL are both active, RH is considered to be a therapeutically inactive, possibly toxic, metabolite. This article reviews the pharmacodynamic and pharmacokinetic properties of HL and RH and the possible clinical effects that can result from this reversible metabolism. PMID:12369591

Jann, M W; Lam, Y W; Gray, E C; Chang, W H

1994-01-01

247

Reversible logic for supercomputing.  

SciTech Connect

This paper is about making reversible logic a reality for supercomputing. Reversible logic offers a way to exceed certain basic limits on the performance of computers, yet a powerful case will have to be made to justify its substantial development expense. This paper explores the limits of current, irreversible logic for supercomputers, thus forming a threshold above which reversible logic is the only solution. Problems above this threshold are discussed, with the science and mitigation of global warming being discussed in detail. To further develop the idea of using reversible logic in supercomputing, a design for a 1 Zettaflops supercomputer as required for addressing global climate warming is presented. However, to create such a design requires deviations from the mainstream of both the software for climate simulation and research directions of reversible logic. These deviations provide direction on how to make reversible logic practical.

DeBenedictis, Erik P.

2005-05-01

248

Reversible logic for supercomputing.  

SciTech Connect

This paper is about making reversible logic a reality for supercomputing. Reversible logic offers a way to exceed certain basic limits on the performance of computers, yet a powerful case will have to be made to justify its substantial development expense. This paper explores the limits of current, irreversible logic for supercomputers, thus forming a threshold above which reversible logic is the only solution. Problems above this threshold are discussed, with the science and mitigation of global warming being discussed in detail. To further develop the idea of using reversible logic in supercomputing, a design for a 1 Zettaflops supercomputer as required for addressing global climate warming is presented. However, to create such a design requires deviations from the mainstream of both the software for climate simulation and research directions of reversible logic. These deviations provide direction on how to make reversible logic practical

DeBenedictis, Erik P.

2004-12-01

249

Reversible Cellular Automata  

Microsoft Academic Search

\\u000a Reversible cellular automata (RCA) are models of massively parallel computation that preserve information. This paper is a\\u000a short survey of research on reversible cellular automata over the past fourty plus years. We discuss the classic results by\\u000a Hedlund, Moore and Myhill that relate injectivity, surjectivity and reversibility with each other. Then we review algorithmic\\u000a questions and some results on computational

Jarkko Kari

2005-01-01

250

N-Hexyl-4-aminobutyl glycosides for investigating structures and biological functions of carbohydrates.  

PubMed

The potential applications of N-hexyl-4-aminobutyl glycosides in the mass spectrometric investigation of glycan structure and in the investigation of glycan functions were studied. Under collision-induced dissociation (CID) conditions, sodiated glycosides carrying N-hexyl-4-aminobutyl groups effectively produced a hemiacetal species (C-ions), which is important in mass-spectrometry-based structural investigation. The usefulness of N-hexyl-4-aminobutyl glycosides in biological analysis was also confirmed by obtaining a binding constant for the binding of dipyrrometheneboron difluoride C3-labeled N-hexyl-4-aminobutyl beta-lactoside with an Erythrina cristagalli lectin, and by visualizing cellular organelles using a more hydrophobic BODIPY-labeled compound. PMID:19865710

Suzuki, Katsuhiko; Tobe, Akifumi; Adachi, Shin; Daikoku, Shusaku; Hasegawa, Yasuko; Shioiri, Yuki; Kobayashi, Mariko; Kanie, Osamu

2009-09-08

251

Glycosidic aroma precursors of Syrah and Chardonnay grapes after an oak extract application to the grapevines.  

PubMed

Syrah and Chardonnay grapevines were treated with an oak extract in order to determine the effect on glycosidic aroma precursors. Grapevines were treated at three different timings of the veraison (treatment 1, 2 and 3). Aglycons were obtained by enzymatic hydrolysis, and these were identified and quantified by means of gas chromatography-mass spectrometry (GC-MS). Results suggest that after the applications the majority of compounds from the oak extract were assimilated and stored as glycosidic forms in both cultivars. Also, other compounds not present in the extract were affected, with a different behaviour observed depending on the timing of application and the variety. In general, C6 compounds, alcohols, terpenes, phenols and C13-norisoprenoids in Syrah showed a decrease and in Chardonnay an increase. Thus, this study proved a change in the glycosidic aroma profile in grapes after the oak application, so these treated grapes could produce wines with different aromatic quality. PMID:23411201

Martínez-Gil, Ana M; Angenieux, Magaly; Pardo-García, Ana I; Alonso, Gonzalo L; Ojeda, Hernán; Rosario Salinas, M

2012-11-15

252

New isoflavone glycosides from Iris spuria L. (Calizona) cultivated in Egypt  

Microsoft Academic Search

Two new isoflavone glycosides, tectorigenin 7-O-?-d-glucopyranoside-4?-O-[?-d-glucopyranosyl-(1?? ? 6???)-?-d-glucopyranoside] (1) and iristectorigenin B 4?-O-[?-d-glucopyranosyl-(1??? ? 6?)-?-d-glucopyranoside] (2), together with 11 known compounds, including six isoflavones, tectorigenin 7-O-?-d-glucopyranoside-4?-O-?-d-glucopyranoside (3), tectorigenin 4?-O-[?-d-glucopyranosyl-(1??? ? 6?)-?-d-glucopyranoside] (4), tectorigenin 7-O-?-d-glucopyranoside (5), genistein 7-O-?-d-glucopyranoside (6), tectorigenin 4?-O-?-d-glucopyranoside (7), and tectorigenin (8); two phenolic acid glycosides, vanillic acid 4-O-?-d-glucopyranoside (9) and glucosyringic acid (10); a phenylpropanoid glycoside, E-coniferin (11); an auronol derivative, maesopsin 6-O-?-d-glucopyranoside

Salwa F. Farag; Yuka Kimura; Hideyuki Ito; Junko Takayasu; Harukuni Tokuda; Tsutomu Hatano

2009-01-01

253

New insights into the structure-cytotoxicity relationship of spirostan saponins and related glycosides.  

PubMed

A variety of spirostan saponins and related glycosides were synthesized and evaluated for their cytotoxicity against the human myeloid leukemia cell line (HL-60). A linear glycosylation strategy allowed for accessing a variety of functionalization patterns at both the spirostanic and the saccharide moieties, which provides new information regarding the structure-cytotoxicity relationship of this family of steroidal glycosides. Intriguing results were achieved with respect to hecogenyl and 5?-hydroxy-laxogenyl ?-chacotriosides, turning out to be the former very cytotoxic and the latter no cytotoxic at all. Importantly, the partially pivaloylated ?-d-glucosides of 5?-hydroxy-laxogenin were the most potent cytotoxic compounds among all tested glycosides. This comprises the first report on acylated spirostanyl glucosides displaying significant cytotoxicity, and therefore, it opens up new opportunities toward the development of saponin analogues as anticancer agents. PMID:22405922

Pérez-Labrada, Karell; Brouard, Ignacio; Estévez, Sara; Marrero, María Teresa; Estévez, Francisco; Bermejo, Jaime; Rivera, Daniel G

2012-02-15

254

Cleavage of zearalenone-glycoside, a "masked" mycotoxin, during digestion in swine.  

PubMed

Comparative analyses of cereal samples pretreated with or without beta-glucosidase indicate the presence of zearalenone-glycoside. To examine the stability of zearalenone-glycoside during digestion, mixed feed was artificially contaminated with synthesized zearalenone-4-beta-D-glucopyranoside (395 micrograms/kg) and fed to a pig over a period of 14 days. The metabolites detected in feces and urine samples were zearalenone and alpha-zearalenol. These results demonstrate that zearalenone-4-beta-D-glucopyranoside is decomposed during digestion and the aglucone, zearalenone, is released. Since zearalenone-glycoside is not detected during routine analysis, but hydrolysed during digestion, it seems likely that such "masked mycotoxins" are involved in cases of mycotoxicoses. PMID:2143610

Gareis, M; Bauer, J; Thiem, J; Plank, G; Grabley, S; Gedek, B

1990-05-01

255

Two new bioactive triterpene glycosides from the sea cucumber Pseudocolochirus violaceus.  

PubMed

By activity-guided fractionation, two new triterpene glycosides, violaceusides A (1) and B (2), were isolated from the sea cucumber Pseudocolochirus violaceus as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. By extensive 2D NMR techniques and chemical evidence, the structures of the two new glycosides were established as 16beta-acetoxy-3-O-[3-O-methyl-beta-D-glucopyranosyl-(1 --> 3)-beta-D-xylopyranosyl-(1 --> 4)-beta-D-quinovopyranosyl-(1 --> 2)-4-O-sodiumsulphate-beta-D-xylopyranosyl]-holosta-7,24-diene-3beta-ol (1) and 16beta-acetoxy-3-O-[3-O-methyl-beta-D-glucopyranosyl-(1 --> 3)-beta-D-xylopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 2)-4-O-sodiumsulphate-beta-D-xylopyranosyl]-holosta-7,24-diene-3beta-ol (2), respectively. The two glycosides also exhibited significant cytotoxicity against HL-60 and BEL-7402 cancer cell lines. PMID:16753775

Zhang, Shu-Yu; Yi, Yang-Hua; Tang, Hai-Feng; Li, Ling; Sun, Peng; Wu, Jun

256

Synthesis and evaluation of benzophenone O-glycosides as ?-glucosidase inhibitors.  

PubMed

The first total synthesis of benzophenone O-glycosides (iriflophenone 2-O-?-L-rhamnopyranoside: 1 and aquilarisinin: 2) isolated from the leaves of Aquilaria sinensis and related new derivatives (3-12) was accomplished through suitable protecting group manipulations and glycosylation starting from commercially available L-rhamnose, D-glucose, D-galactose, D-mannose, D-xylose, and 1,3,5-trihydroxybenzene. All synthesized benzophenone O-glycosides were evaluated for their inhibitory activities against ?-glucosidase. Of these, benzophenone O-glycosides 4 and 10 exhibited the most potent inhibitory activity in vitro against ?-glucosidase with IC(50) values of 168.7 ± 13.9 and 210.1 ± 23.9 µM, respectively, when compared with that of the positive control acarbose with an IC(50) value of 569.3 ± 49.7 µM. PMID:22730155

Liu, Qingchao; Guo, Tiantian; Li, Wenhong; Li, Dong; Feng, Zili

2012-06-25

257

The flavonol glycosides in the fruit of Pyrus communis L. cultivar Bon Chrétien.  

PubMed

1. Two new flavonol glycosides were isolated from the fruit of Pyrus communis L. cultivar Bon Chrétien. These were identified as isorhamnetin 3-rhamnogalactoside and a derivative of isorhamnetin 3-glucoside which was associated (possibly acylated) with an unknown aliphatic organic acid. 2. The melting point of isorhamnetin 3-glucoside isolated from Bon Chrétien pears is different from that of isorhamnetin 3-glucoside previously isolated from Argemone mexicana and Calendula officinalis. 3. Isorhamnetin 3-rhamnoglucoside was isolated from the fruit of Pyrus communis L. cultivar Bon Chrétien. This glycoside appears to be identical with narcissin, previously isolated from Narcissus tazetta and Lilium auratum. 4. Isoquercitrin, previously reported to be present in pear leaves, was isolated from the fruit of Bon Chrétien pears. 5. The isolated glycosides were present in the peels and flesh of the fruit, but were absent from the cores. PMID:16749105

Nortjé, B K

1965-10-01

258

Total peroxynitrite scavenging capacity of phenylethanoid and flavonoid glycosides from the flowers of Buddleja officinalis.  

PubMed

Nine compounds, including six phenylethanoid glycosides: acteoside (1); bioside (2); echinacoside (3); poliumoside (4); phenylethyl glycoside (5); salidroside (6) and three flavonoids; linarin (7); apigenin (8); isorhoifolin (9), were isolated from the flowers of Buddleja officinalis MAXIM. (Buddlejaceae). Chemical structures were confirmed by (1)H-, and (13)C-NMR, and MS spectral methods and compared with those reported in the literature. Antioxidant activities of the methanol and water extracts, and all isolated compounds were evaluated using the total oxidant scavenging capacity (TOSC) assay against peroxynitrite. Results of the assay showed that the phenylethanoid glycosides, a major class of compounds of the flowers of B. officinalis, possess strong antioxidant activity. Of these, acteoside, echinacoside and poliumoside have 9.9-, 9.8- and 9.5-fold TOSC value, respectively, compared with the positive control, Trolox. PMID:19952410

Tai, Bui Huu; Jung, Bong Yong; Cuong, Nguyen Manh; Linh, Pham Thuy; Tung, Nguyen Huu; Nhiem, Nguyen Xuan; Huong, Tran Thu; Anh, Ngo Thi; Kim, Jeong Ah; Kim, Sang Kyum; Kim, Young Ho

2009-12-01

259

A concise pathway to synthesize a novel class of pyrido(2,3-d)pyrimidine-C-?-D-glycosides.  

PubMed

A concise pathway to synthesize a novel class of nine different pyrido(2,3-d)pyrimidine-C-?-d-glycosides is reported. Formation of Michael adduct as an intermediate followed by heterocyclization are the key steps and the products were characterized by different spectral studies. ?-Anomeric forms of C-glycosides were assigned from 1H NMR spectroscopy. PMID:23333769

Shanmugam, Muniyappapillai Jeganathan; Mohan Das, Thangamuthu

2012-11-29

260

Differential EI Fragmentation Pathways for Peracetylated C-Glycoside Ketones as a Consequence of Bicyclic Ketal Ring Structures  

Technology Transfer Automated Retrieval System (TEKTRAN)

Several C-glycoside ketones and peracetylated C-glycoside ketones have been synthesized from 13 structurally-diverse aldoses sugars (including isotope labeled [1-**13C]Glc, [U-**13C]Glc, and [6,6’-**2H2]Glc) via an aqueous-based Knoevanagel condensation with aliphatic 1,3-diketones. Sodium adduct m...

261

Hexose keto-C-glycoside conjugates: design, synthesis, cytotoxicity, and evaluation of their affinity for the glucose transporter Glut-1.  

PubMed

The design, synthesis, cytotoxicity, and biological evaluation of carbohydrate/C-glycoside conjugates are described. The design concept is predicted on the idea that physiological barriers like the blood brain barrier could be crossed selectively by using glucose or glucose derivative/drug conjugates. The study demonstrates that, (1) carbohydrates and C-glycosides can be bonded at nonanomeric positions by the reaction of carbohydrate triflates with C-glycoside alkoxydes in the presence of DMPU; (2) there is a structure-activity relationship between the cytotoxicity of the conjugate and the nature of the carbohydrate residue; and (3) peracetylated hexose keto-C-glycoside conjugates are the most cytotoxic keto-C-glycosides. PMID:9022973

Uriel, C; Egron, M J; Santarromana, M; Scherman, D; Antonakis, K; Herscovici, J

1996-12-01

262

Revisiting the armed-disarmed concept rationale: s-benzoxazolyl glycosides in chemoselective oligosaccharide synthesis.  

PubMed

[reaction: see text]. It has been discovered that 2-O-benzyl-3,4,6-tri-O-acyl SBox glycosides are significantly less reactive than even "disarmed" peracylated derivatives. This finding has been applied to the synthesis of various oligosaccharides, the monomeric units of which are connected via cis-cis, trans-cis, and cis-trans sequential glycosidic linkages. Two-stage activation of the armed (benzylated) donor over moderately (dis)armed (acylated) and, subsequently, over disarmed (2-O-benzyl-3,4-O-diacylated) acceptor has also proven to be feasible. PMID:16018624

Kamat, Medha N; Demchenko, Alexei V

2005-07-21

263

Oviposition stimulants for the monarch butterfly: Flavonol glycosides from Asclepias curassavica  

Microsoft Academic Search

The monarch butterfly Danaus plexippus oviposits on milkweed plants, primarily within the Asclepiadaceae. Oviposition stimulants responsible for host plant recognition were isolated from Asclepias curassavica. Six flavonoid glycosides-quercetin 3-O-(2?,6?-?-l-dirhamnopyranosyl)-?-d-galactopyranoside, quercetin 3-O-?-d-glucopyranosyl-(1 ? 6)-?-d-galactopyranoside, quercetin 3-O-(2?-O-?-l-rhamnopyranosyl)-?-d-galactopyranoside, quercetin 3-O-?-l-rhamnopyranosyl-(1 ? 6-?-d-glucopyranoside, quercetin 3-O-?-d-galactopyranoside, quercetin 3-O-?-d-glucopyranoside, and an unidentified flavonoid mixture were isolated and characterized from this plant. An additional glycoside, possibly quercetin

Meena Haribal; J. Alan A. Renwick

1996-01-01

264

Cordifolide A, a sulfur-containing clerodane diterpene glycoside from Tinospora cordifolia.  

PubMed

Cordifolide A (1), a novel unprecedented sulfur-containing clerodane diterpene glycoside, together with other two new diterpene glycosides, cordifolides B (2) and C (3), and four known analogues, was isolated from a methanol-soluble extract of the stems of Tinospora cordifolia. The structures of the new compounds were determined on the basis of spectroscopic data interpretation, with that of cordifolide A (1) confirmed by a single-crystal X-ray crystallographic analysis. All isolates were evaluated for their in vitro immunomodulatory activity using mouse bone marrow-derived dentritic cells (BMDCs). PMID:22497272

Pan, Li; Terrazas, Cesar; Lezama-Davila, Claudio M; Rege, Nirmala; Gallucci, Judith C; Satoskar, Abhay R; Kinghorn, A Douglas

2012-04-12

265

Cordifolide A, a Sulfur-containing Clerodane Diterpene Glycoside from Tinospora cordifolia  

PubMed Central

Cordifolide A (1), a novel unprecedented sulfur-containing clerodane diterpene glycoside, together with other two new diterpene glycosides, cordifolides B (2) and C (3), and four known analogues, was isolated from a methanol-soluble extract of the stems of Tinospora cordifolia. The structures of the new compounds were determined on the basis of spectroscopic data interpretation, with that of cordifolide A (1) confirmed by a single-crystal X-ray crystallographic analysis. All isolates were evaluated for their in vitro immunomodulatory activity using mouse bone marrow-derived dentritic cells (BMDCs).

Pan, Li; Terrazas, Cesar; Lezama-Davila, Claudio M.; Rege, Nirmala; Gallucci, Judith C.; Satoskar, Abhay R.; Kinghorn, A. Douglas

2012-01-01

266

Two flavonol glycosides, hexandrasides C and D, from the underground parts of Vancouveria hexandra.  

PubMed

In addition to four known glycosides, icariin, epimedin B, epimedosides A and E, two new glycosides of a flavonol with a gamma,gamma-dimethylallyl group were isolated from the underground parts of Vancouveria hexandra. The structures were determined to be des-O-methyl-anhydroicaritin 3-O-beta-D-xylopyranosyl(1----2)-alpha-L-rhamnopyranoside 7-O-beta-D-glucopyranosyl(1----2)-beta-D-glucopyranoside and anhydroicaritin 3-O-alpha-L-rhamnopyranosyl(1----3)-alpha-L-rhamnopyranoside 7-O-beta-D-glucopyranoside by means of spectral analysis. PMID:1367784

Mizuno, M; Kanie, Y; Iinuma, M; Tanaka, T; Lang, F A

1991-01-01

267

C(22)-steroidal lactone glycosides from stems and leaves of Paris polyphylla var. yunnanensis.  

PubMed

Further phytochemical investigation on the stems and leaves of Paris polyphylla var. yunnanensis has led to the isolation of three C(22)-steroidal lactone glycosides. Two of these are new compounds, designated as chonglouoside SL-7 (1) and chonglouoside SL-8 (2). Their structures were elucidated on the basis of extensive spectroscopic analysis, as well as comparison with the reported spectroscopic data. This is the first report of C(22)-steroidal lactone glycosides isolated from the Paris genus. Compounds 1 and 3 showed moderate antimicrobic activity against Propionibacterium acnes with MIC values of 31.3 and 3.9?g/mL, respectively. PMID:23262268

Qin, Xu-Jie; Chen, Chang-Xiang; Ni, Wei; Yan, Huan; Liu, Hai-Yang

2012-12-20

268

Linckosides A and B, two new neuritogenic steroid glycosides from the Okinawan starfish Linckia laevigata.  

PubMed

Two new steroid glycosides, named linckosides A and B, were isolated from the Okinawan starfish Linckia laevigata, and their stereostructures were elucidated by spectroscopic methods and chemical derivatization. Each of them possesses two monosaccharide units at C-3 and C-29 of a polyhydroxylated steroid aglycon. These steroid glycosides showed not only notable neuritogenic activity against PC12 cells but also significant synergistic effects on the NGF-induced neuronal differentiation of PC12 cells. Linckoside B showed higher activities than those of linckoside A, though the structural difference is only the kind of a sugar. PMID:11937355

Qi, Jianhua; Ojika, Makoto; Sakagami, Youji

2002-06-01

269

Flavone-di- C-glycosides in citrus juices from Southern Italy  

Microsoft Academic Search

6,8-Di-C-glucopyranosylapigenin and 6,8-di-C-glucopyranosyldiosmetin were detected by HPLC–DAD–ESI–MS–MS in a variety of Southern Italian Citrus juices (orange, lemon, bergamot, citron, mandarin, clementine). In some juices, the amounts of C-glycosides detected were significant. 6,8-Di-C-glucopyranosylapigenin is characteristic of orange juice, while 6,8-di-C-glucopyranosyldiosmetin is the most important C-glycoside in lemon and citron juice. In bergamot juice the concentrations of 6,8-di-C-glucopyranosylapigenin and 6,8-di-C-glucopyranosyldiosmetin are similar.

Corrado Caristi; Ersilia Bellocco; Claudia Gargiulli; Giovanni Toscano; Ugo Leuzzi

2006-01-01

270

Catalytic Mechanism of Retaining ?-Galactosidase Belonging to Glycoside Hydrolase Family 97  

Microsoft Academic Search

Glycoside hydrolase family 97 (GH 97) is a unique glycoside family that contains inverting and retaining glycosidases. Of these, BtGH97a (SusB) and BtGH97b (UniProtKB\\/TrEMBL entry Q8A6L0), derived from Bacteroides thetaiotaomicron, have been characterized as an inverting ?-glucoside hydrolase and a retaining ?-galactosidase, respectively. Previous studies on the three-dimensional structures of BtGH97a and site-directed mutagenesis indicated that Glu532 acts as an

Masayuki Okuyama; Momoyo Kitamura; Hironori Hondoh; Min-Sun Kang; Haruhide Mori; Atsuo Kimura; Isao Tanaka; Min Yao

2009-01-01

271

C-Aryl glycoside inhibitors of SGLT2: Exploration of sugar modifications including C-5 spirocyclization.  

PubMed

Modifications to the sugar portion of C-aryl glycoside sodium glucose transporter 2 (SGLT2) inhibitors were explored, including systematic deletion and modification of each of the glycoside hydroxyl groups. Based on results showing activity to be quite tolerant of structural change at the C-5 position, a series of novel C-5 spiro analogues was prepared. Some of these analogues exhibit low nanomolar potency versus SGLT2 and promote urinary glucose excretion (UGE) in rats. However, due to sub-optimal pharmacokinetic parameters (in particular half-life), predicted human doses did not meet criteria for further advancement. PMID:20149653

Robinson, Ralph P; Mascitti, Vincent; Boustany-Kari, Carine M; Carr, Christopher L; Foley, Patrick M; Kimoto, Emi; Leininger, Michael T; Lowe, Andre; Klenotic, Michelle K; Macdonald, James I; Maguire, Robert J; Masterson, Victoria M; Maurer, Tristan S; Miao, Zhuang; Patel, Jigna D; Préville, Cathy; Reese, Matthew R; She, Li; Steppan, Claire M; Thuma, Benjamin A; Zhu, Tong

2010-01-21

272

Reversing Motion Vector Fields  

Microsoft Academic Search

We examine the problem of estimating a reverse motionvector field from a given forward motion vector fieldand its motion-compensated residual. This problem haspractical importance when providing reverse-play functionalityin compressed video environments, where video data isstored, processed, and transported in compressed form. Wepresent a family of algorithms that trade off motion vectoraccuracy for computational efficiency. Experimental resultsdemonstrate the performance of these...

Susie J. Wee

1998-01-01

273

Energy by reverse electrodialysis  

Microsoft Academic Search

The use of reverse electrodialysis, a reverse desalinization process, to derive energy from the difference between the chemical potentials of concentrated and dilute salt solutions is evaluated. The process employs the flows of brine and dilute solutions through alternating cells bounded by cation- and anion-exchange membranes in a stack placed between two electrodes to generate a voltage by the passage

R. E. Lacey

1980-01-01

274

Evaluation of the glycoside hydrolase activity of a Brettanomyces strain on glycosides from sour cherry (Prunus cerasus L.) used in the production of special fruit beers.  

PubMed

The glycoside hydrolase activity of Saccharomyces cerevisiae and Brettanomyces custersii was examined on sour cherry (Prunus cerasus L.) glycosides with bound volatile compounds. Refermentations by the beta-glucosidase-negative S. cerevisiae strains LD25 and LD40 of sour cherry juice-supplemented beer demonstrated only a moderate increase of volatiles. In contrast, the beta-glucosidase-positive B. custersii strain LD72 showed a more pronounced activity towards glycosides with aliphatic alcohols, aromatic compounds and terpenoid alcohols. Important contributors to sour cherry aroma such as benzaldehyde, linalool and eugenol were released during refermentation as shown by analytical tools. A gradually increasing release was observed during refermentations by B. custersii when whole sour cherries, sour cherry pulp or juice were supplemented in the beer. Refermentations with whole sour cherries and with sour cherry stones demonstrated an increased formation of benzyl compounds. Thus, amygdalin was partially hydrolysed, and a large part of the benzaldehyde formed was mainly reduced to benzyl alcohol and some further esterified to benzyl acetate. These findings demonstrate the importance and interesting role of certain Brettanomyces species in the production of fruit lambic beers such as 'Kriek'. PMID:18673394

Daenen, Luk; Sterckx, Femke; Delvaux, Freddy R; Verachtert, Hubert; Derdelinckx, Guy

2008-07-30

275

A New ent-Labdane Diterpene Glycoside form the Leaves of Casearia sylvestris  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sylvestin (1), a new ent-labdane glycoside, was isolated from the leaves of Casearia sylvestris. The structure was determined on the basis of 1D and 2 D NMR and HR-ESI-MS analyses. The diterpenoid of ent-labdane type was isolated for the first time from C. sylvestris....

276

Theoretical Calculation of Electronic Circular Dichroism of a Hexahydroxydiphenoyl-Containing Flavanone Glycoside  

Technology Transfer Automated Retrieval System (TEKTRAN)

Time-dependent density functional theory (TDDFT) was employed for theoretical calculation of electronic circular dichroism (ECD) of a hexahydroxydiphenoyl (HHDP)-containing flavanone glycoside, mattucinol-7-O-[4'',6''-O-(aS)-hexahydroxydiphenoyl]-ß-d-glucopyranoside (2). It identified the roles of t...

277

Structural complexes in the squid giant axon membrane sensitive to ionic concentrations and cardiac glycosides  

Microsoft Academic Search

Giant nerve fibers of squid Sepioteuthis sepioidea were incubated for 10 min in artificial sea water (ASW) under control conditions, in the absence of various ions, and in the presence of cardiac glycosides. The nerve fibers were fixed in OsO, and embedded in Epon, and structural complexes along the axolemma were studied. These complexes consist of a portion of axolemma

GLORIA M. VILLEGAS; JORGE VILLEGAS

1976-01-01

278

Fomitoside K, a New Lanostane Triterpene Glycoside from the Fruiting Body of Fomitopsis nigra  

PubMed Central

In an effort to identify the chemical constituents of fruiting bodies of Fomitopsis pinicola, a new lanostane triterpene glycoside, designated as fomitoside K, has been isolated from its methanolic extract. Its chemical structure was assigned on the basis of various spectroscopic studies.

Lee, In-Kyoung; Jung, Jin-Young; Yeom, Ji-Hee; Ki, Dae-Won; Lee, Myeong-Seok; Yeo, Woon-Hyung

2012-01-01

279

Effects of Cardiac Glycosides on Electrical Activity in the Isolated Retina of the Frog  

Microsoft Academic Search

Ouabain added to physiological salt solutions bathing the isolated frog retina irreversibly abolishes the electrical response to light (the electroretino- gram or ERG). The time course of abolition depends on the concentration of ouabain in the medium and the surface of the retina to which it is applied. When the glycoside is placed on the receptor surface, in 7 min

ROBERT N. FRANK; TIMOTHY H. GOLDSMITH

1967-01-01

280

Enhancement of production of eugenol and its glycosides in transgenic aspen plants via genetic engineering.  

PubMed

Eugenol, a volatile phenylpropene found in many plant species, exhibits antibacterial and acaricidal activities. This study attempted to modify the production of eugenol and its glycosides by introducing petunia coniferyl alcohol acetyltransferase (PhCFAT) and eugenol synthase (PhEGS) into hybrid aspen. Gas chromatography analyses revealed that wild-type hybrid aspen produced small amount of eugenol in leaves. The heterologous overexpression of PhCFAT alone resulted in up to 7-fold higher eugenol levels and up to 22-fold eugenol glycoside levels in leaves of transgenic aspen plants. The overexpression of PhEGS alone resulted in a subtle increase in either eugenol or eugenol glycosides, and the overexpression of both PhCFAT and PhEGS resulted in significant increases in the levels of both eugenol and eugenol glycosides which were nonetheless lower than the increases seen with overexpression of PhCFAT alone. On the other hand, overexpression of PhCFAT in transgenic Arabidopsis and tobacco did not cause any synthesis of eugenol. These results indicate that aspen leaves, but not Arabidopsis and tobacco leaves, have a partially active pathway to eugenol that is limited by the level of CFAT activity and thus the flux of this pathway can be increased by the introduction of a single heterologous gene. PMID:23707945

Koeduka, Takao; Suzuki, Shiro; Iijima, Yoko; Ohnishi, Toshiyuki; Suzuki, Hideyuki; Watanabe, Bunta; Shibata, Daisuke; Umezawa, Toshiaki; Pichersky, Eran; Hiratake, Jun

2013-05-23

281

Extraction of iridoid glycosides and their determination by micellar electrokinetic capillary chromatography  

Microsoft Academic Search

Several methods for the extraction of two iridoid glycosides, catalpol and aucubin, from the plant matrix (Veronica longifolia leaves) were compared. Pressurized hot water extraction and hot water extraction were the most efficient isolation techniques for both. Pressurized liquid extraction and maceration with various organic solvents were also tested. Relative to the amounts extracted with hot water, ethanol extracted only

Johanna Suomi; Heli Sirén; Kari Hartonen; Marja-Liisa Riekkola

2000-01-01

282

Synthesis of the C-glycoside of ?-d-mannose-(1 ? 6)-d-myo-inositol.  

PubMed

The dimannosylatedinositol pseudotrisaccharide phospholipid of the lipoarabinomannan (LAM) component of the mycobacterial cell wall has attracted interest as a therapeutic target because of its uniqueness to mycobacteria, its assembly at an early stage in LAM biosynthesis and the immunological activity of oligosaccharides containing this subunit. Accordingly, analogues of this pseudotrisaccharide, ?-d-mannose-(1 ? 2)-?-d-mannose-(1 ? 6)-d-myo-inositol are of interest as mechanistic probes and drug leads. C-glycosides are of special interest because of their hydrolytic stability and conformational differences compared to O-glycosides. Herein, as a prelude to C-glycoside analogues of this pseudotrisaccharide, we describe the synthesis of the C-glycoside of ?-d-mannose-(1 ? 6)-d-myo-inositol. The synthetic strategy centers on the elaboration of a C1-linked glycal-inositol, the glycone segment of which is assembled via an oxocarbenium ion cyclization on a thioacetal-enol ether precursor that originates from "glycone" and "aglycone" components. PMID:24057020

Hans, Sunej; Altiti, Ahmad; Mootoo, David R

2013-09-25

283

Hydrolysis of terpenyl glycosides in grape juice and other fruit juices: a review  

Microsoft Academic Search

The importance of monoterpenes on varietal flavour of must and other fruit juices has been reviewed. These compounds were mainly found linked to sugar moieties in grape juice and wines, showing no olfactory characteristics. In this way, analytical techniques developed to study these compounds, in both free or glycosidically forms, are discussed. Mechanisms to liberate terpenes were studied, making a

Sergi Maicas; José Juan Mateo

2005-01-01

284

Research on the isolation and characterisation of 3-ramno- glycoside quercitine from Rosa canina  

Microsoft Academic Search

In this paper we aim at valorising natural bioactive principles from the spontaneous flora belonging to the geographical areas in Western România (Timi? and Cara?-Severin Counties) by isolating and characterising 3 - ramno - glycoside quercitine (rutin) from dog rose (Rosa canina). We accessed different solvent systems for the solid\\/liquid extraction (alcohols, acetone, benzene, etc.) and then we replicated re-crystallisations.

C. Jianu; Monica Butnariu; Ileana Cocan; Cristina Rujescu; A. Rinovetz; I. Jianu

285

Synthesis of carbasugar-containing non-glycosidically linked pseudodisaccharides and higher pseudooligosaccharides.  

PubMed

This minireview covers synthetic methods towards carbasugar-containing non-glycosidically linked pseudodisaccharides or higher pseudooligosaccharides. Carbocyclic pyranose mimetics (saturated or unsaturated between C-5 and C-5a) are linked by ether, thioether or amine bridges to carbohydrates or other carbasugars. PMID:19833325

Cumpstey, Ian

2009-09-16

286

DFT STUDY OF ALPHA-MALTOSE: INFLUENCE OF HYDROXYL ORIENTATIONS ON THE GLYCOSIDIC BOND  

Technology Transfer Automated Retrieval System (TEKTRAN)

The result of DFT geometry optimization of 68 unique alpha-maltose conformers at the B3LYP/6-311++G** level of theory is described. Particular attention is paid to the hydroxyl group rotational positions and their influence on the glycosidic bond dihedral angles. The orientation of lone pair elect...

287

Studies on the synthesis of C-Glycoside sulfones as potential glycosyl transferase inhibitors  

Microsoft Academic Search

?-C-Glycoside sulfoxides and sulfones were prepared by radical addition of thiol acetic acid to exocyclic glycals followed by deacetylation, S-alkylation, and selective oxidation. These compounds are representative examples of a new class of molecules designed to be glycosyl transferase inhibitors.

Jacquelyn Gervay; Terrence M. Flaherty; Daniel Holmes

1997-01-01

288

Synthesis and antioxidant activity of a novel class of fluorescein-based ?-C-glycosides.  

PubMed

A series of fluorescein-based ?-C-glycosyl ketones were synthesized through aldol condensation of ?-C-glycosyl ketones with fluorescein monoaldehyde under ambient reaction conditions in good yields. Formation of the expected product has been confirmed through different spectral techniques. Fluorescein-based ?-C-glycosides show moderate anti-oxidant activities with maximum inhibitory activity of 60%. PMID:23867296

Rajasekar, Mani; Das, Thangamuthu Mohan

2013-06-28

289

Application of silver N-heterocyclic carbene complexes in O-glycosidation reactions  

PubMed Central

We report the efficient O-glycosidation of glycosyl bromides with therapeutically relevant acceptors facilitated by silver N-heterocyclic carbene (Ag-NHC) complexes. A set of four Ag-NHC complexes was synthesized and evaluated as promoters for glycosidation reactions. Two new bis-Ag-NHC complexes derived from ionic liquids 1-benzyl-3-methyl-1H-imidazolium chloride and 1-(2-methoxyethyl)-3-methyl-1H-imidazolium chloride were found to efficiently promote glycosidation, whereas known mono-Ag complexes of 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride and 1,3-bis(2,6-di-isopropylphenyl)imidazolium chloride failed to facilitate the reaction. The structures of the promoters were established by X-ray crystallography, and these complexes were employed in the glycosidation of different glycosyl bromide donors with biologically valuable acceptors, such as estrone, estradiol, and various flavones. The products were obtained in yields considered good to excellent, and all reactions were highly selective for the ? isomer regardless of neighboring group effects.

Talisman, Ian J.; Kumar, Vineet; Deschamps, Jeffrey R.; Frisch, Mark

2011-01-01

290

Isolation of 20 glycosides from the starfish Henricia downeyae, collected in the Gulf of Mexico.  

PubMed

Thirteen new (1-13) and seven known (14-20) steroid glycosides were isolated from Henricia downeyae, collected from the offshore waters of the northern Gulf of Mexico. Ethanolic extracts of these starfish caused growth inhibition in bacteria and fungi, potent antifouling activity against barnacle and bryozoan larvae, and feeding deterrent activity against a marine fish. The known compounds are typical glycosides found in several species of the family Echinasteridae, i.e., Echinaster sp. and Henricia laeviuscola. One of the new compounds belongs to this group, whereas the remaining 12 new compounds represent a novel series of steroid glycosides which have aglycons with structural similarities to the "asterosaponins". They possess a delta 9(11) 3 beta, 6 alpha-dihydroxysteroidal aglycon with 23-oxo or 22,23-epoxy functionalities and often a 20-hydroxyl group in the side chain. The sulfate is located at C-6 and the saccharide moiety at C-3, in contrast with the asterosaponins which have the sulfate at C-3 and the oligosaccaride moiety at C-6. All the new compounds contain a glucuronic acid unit, which is uncommon among steroid glycosides from echinoderms. The structures of the new compounds, isolated in amounts ranging from 3.4 to 0.9 mg, were determined by interpretation of their spectral data and by comparison with spectral data of known compounds. PMID:8699179

Palagiano, E; Zollo, F; Minale, L; Iorizzi, M; Bryan, P; McClintock, J; Hopkins, T

1996-04-01

291

Bromonium ion-promoted glycosidic bond formation and simultaneous bromination of an activated aryl aglycon.  

PubMed

N-Bromosuccinimide (NBS) together with a catalytic amount of Me(3)SiOTf was found to be effective for the activation of thioglycosides. Concurrently with formation of the glycosidic bond, bromination took place on the activated aromatic ring of a 4-methoxyphenyl aglycon. PMID:11755909

Qin, Zhi-Hui; Li, Hui; Cai, Meng-Shen; Li, Zhong-Jun

2002-01-01

292

Lewis acid-catalyzed stereoselective lactonization and subsequent glycosidation of 2-C-malonyl carbohydrates.  

PubMed

Gold(III) bromide is a suitable catalyst for the stereoselective cyclization of 2-C-malonyl carbohydrates to the anomeric center under retention of one ester group. Reopening of the lactones with alcohols in the presence of TMSOTf affords allyl, propargyl and benzyl glycosides with high ?-selectivity. PMID:21833421

Pimpalpalle, Tukaram M; Vidadala, Srinivasa Rao; Hotha, Srinivas; Linker, Torsten

2011-08-11

293

7-O-Methylpelargonidin glycosides from the pale red flowers of. Catharanthus roseus.  

PubMed

Two new anthocyanidin glycosides were isolated from the pale red flowers of Catharanthus roseus 'Equator Apricot with Red Eye', and identified as 7-O-methylpelargonidin 3-O-[6-O-(alpha-rhamnopyranosyl)-beta-galactopyranoside] and 7-O-methylpelargonidin 3-O-(beta-galactopyranoside) by chemical and spectroscopic methods. PMID:24079176

Tatsuzawa, Fumi

2013-08-01

294

Structure elucidation and complete NMR spectral assignments of new furostanol glycosides from Solanum torvum.  

PubMed

Two new furostanol glycosides, torvosides O (1) and P (2), were isolated from leaves of Solanum torvum. Their structures were completely and unambiguously assigned by one- and two-dimensional NMR techniques ((1)H NMR, (13)C NMR, TOCSY, HSQC, ROESY and HMBC), ESI-MS spectrometry and chemical methods. PMID:19544362

Lu, Yuanyuan; Luo, Jianguang; Kong, Lingyi

2009-09-01

295

Isolation and Structure Elucidation of Three Glycosides and a Long Chain Alcohol from Polianthes Tuberosa Linn  

Microsoft Academic Search

Three glycosides and a long chain alcohol were isolated from the bulbs of Polianthes tuberosa , these were identified as 3,29-dihydroxystigmast-5-ene-3- O - g - d -galactopyranoside ( 1 ) 1 , ethyl g - d -galactopyranoside ( 2 ), ethyl- f - d -galactopyranoside ( 3 ), and 1-tricosanol ( 4 ). The structures were determined by extensive spectroscopic

Khalid Mohammed Khan; Shahnaz Perveen; S. Abdul Majid Ayattollahi; Nikhat Saba; Adil Rashid; Sadiqa Firdous; Syed Moazzam Haider; Zia Ullah; Shagufta Rahat; Zarrar Khan

2002-01-01

296

An anti-inflammatory and anti-microbial flavone glycoside from flowers of Cleome viscosa  

PubMed Central

Background Natural products isolated from plant sources have been demonstrated as potential candidates against several ailments. The scientific investigations on the underlying principles of phytotherapy can pave way for the convergence of traditional medicines and modern science and technologies. Results Quercetin 3-O-(2??-acetyl)-glucoside obtained from ethyl acetate fraction of Cleome viscosa is studied against inflammatory of carrageenan-induced rat paw edema ( in vivo) and microbial activity on ( in vitro). The structure of the glycoside is confirmed by means of hydrogen-1 nuclear magnetic resonance spectroscopy, carbon nuclear magnetic resonance spectroscopy, attached proton test, and mass spectrum. The flavonoid glycoside showed significant anti-inflammatory activity of on carrageenan-induced rat paw edema ( in vivo) and anti-microbial activity ( in vitro) on Staphylococcus aureus (gram positive) and Escherichia coli (gram negative). The anti-inflammatory effect of the flavonoid glycoside may be due to the inhibition of prostaglandin synthesis. Selective toxicity with flavonoid glycoside towards the gram-positive bacteria was found on S. aureus. Conclusions The present study reveals the anti-inflammatory and antimicrobial activities of an isolated quercetin 3-O-(2??-acetyl)-glucoside from a natural source ( C. viscosa).

2012-01-01

297

Ginsenoside Rf2, a new dammarane glycoside from Korean red ginseng (Panax ginseng).  

PubMed

A new dammarane glycoside named ginsenoside Rf2 has been isolated from Korean red ginseng (Panax ginseng) and its chemical structure has been elucidated as 6-O-[alpha-L-rhamnopyranosyl (1-->2) beta-D-glucopyranosyl]dammarane-3 beta, 6 alpha, 12 beta, 20(R), 25-pentol by chemical and spectral methods. PMID:9875504

Park, J D; Lee, Y H; Kim, S I

1998-10-01

298

Differential El Ion Fragmentation Pathways for Peracetylated C-Glycoside Ketals  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aqueous-based Knoevenagel condensation of sugars with beta-diketones is a useful method for preparing beta-C-glycoside ketones. A mechanism has been proposed in which C-C bond formation between the anomeric sugar carbon and the bridged methylene of the diketone is followed by beta-elimination of wa...

299

Potential anti-inflammatory phenolic glycosides from the medicinal plant Moringa oleifera fruits  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bioassay-guided isolation and purification of the ethyl acetate extract of Moringa oleifera fruits yielded three new phenolic glycosides; 4-[(2'-O-acetyl-a-L-rhamnosyloxy) benzyl]isothiocyanate (1), 4-[(3'-O-acetyl-a-L-rhamnosyloxy)benzyl]isothiocyanate (2), and S-methyl-N-{4-[(a-L-rhamnosyloxy)benz...

300

Synergistic effect of isoflavone glycosides and fructooligosaccharides on postgastrectomy osteopenia in rats  

PubMed Central

Fructooligosaccharides stimulate the growth of Bifidobacteria, which cleave isoflavone glycosides to yield corresponding aglycones, and convert metabolites by enhancing enterohepatic recirculation of isoflavones in rats. In the present study, we determined the synergistic effect of dietary isoflavone glycosides and fructooligosaccharides on postgastrectomy osteopenia in rats. Nine-week-old male Sprague-Dawley rats were gastrectomized (n = 20) or sham operated, (control, n = 5) and then randomly assigned to 5 diet groups: sham-a purified diet control, gastrectomized-control, gastrectomized-isoflavone (0.2% isoflavone glycosides), gastrectomized-fructooligosaccharides (7.5% fructooligosaccharides), and isoflavone and fructooligosaccharides (0.2% isoflavone glycosides + 7.5% fructooligosaccharides). After 6 weeks, the rats were killed and biological samples were collected. In gastrectomized rats, fructooligosaccharides prevented femoral bone fragility, but isoflavone without fructooligosaccharides did not inhibit postgastrectomy osteopenia. Isoflavone and fructooligosaccharides exhibited a synergistic in the distal metaphyseal trabecular bone, indicated by peripheral quantitative computed tomography. Moreover, fructooligosaccharides increased calcium absorption and equol production from daidzein in gastrectomized rats. These results indicate that isoflavone alone did not inhibit postgastrectomy osteopenia, but the combination of isoflavone and fructooligosaccharides improved the inhibition of trabecular bone loss by increasing calcium absorption and equol production through fructooligosaccharides supplementation.

Kimira, Yoshifumi; Tajima, Kiyono; Ohta, Atsutane; Ishimi, Yoshiko; Katsumata, Shin-ichi; Suzuki, Kazuharu; Adlercreutz, Herman; Uehara, Mariko

2012-01-01

301

Improvement of corn stover bioconversion efficiency by using plant glycoside hydrolase  

Microsoft Academic Search

Plant cell wall is the most abundant substrate for bioethanol production, and plants also represent a key resource for glycoside hydrolase (GH). To exploit efficient way for bioethanol production with lower cellulase loading, the potential of plant GH for lignocellulose bioconversion was evaluated. The GH activity for cell wall proteins (CWPs) was detected from fresh corn stover (FCS), and the

Yejun Han; Hongzhang Chen

2011-01-01

302

Structural insights into glycoside hydrolase family 32 and 68 enzymes: functional implications  

Microsoft Academic Search

Glycoside hydrolases (GH) have been shown to play unique roles in various biological processes like the biosynthesis of glycans, cell wall metabolism, plant defence, signalling, and the mobilization of storage reserves. To date, GH are divided into more than 100 families based upon their overall structure. GH32 and GH68 are combined in clan GH-J, not only harbouring typical hydrolases but

Willem Lammens; Katrien Le Roy; Lindsey Schroeven; AndreVan Laere; Anja Rabijns; Wim Van den Ende

2009-01-01

303

Mechanism?Based Inhibitors to Probe Transitional States of Glycoside Hydrolases  

Microsoft Academic Search

Recent structural and kinetic studies indicate that glycosidases (glycoside hydrolases) change the peripheral structure of their catalytic sites dynamically to trim glycan structures. Inhibitors that label specific amino acid residues in the active site of these enzymes based on its mechanism of action are powerful tools to probe such a hidden transitional state. This chapter describes methods of mechanism?based irreversible

Hiroshi Hinou; Masaki Kurogochi

2006-01-01

304

Analysis of the key active subsites of glycoside hydrolase 13 family members  

Microsoft Academic Search

?-Amylase, pullulanase, neopullulanase, cyclomaltodextrinase (CDase), cyclomaltodextin glucanotransferase (CGTase), etc. are some of the amylolytic enzymes that act on polysaccharides. These enzymes differ from each other with respect to substrate and linkage specificities. These enzymes have been grouped into the GH13 (GH, Glycoside Hydrolase) family in the CAZy database on the basis of similarity in amino acid sequence. Members of this

Vikash Kumar

2010-01-01

305

The Structural Basis for Exopolygalacturonase Activity in a Family 28 Glycoside Hydrolase  

Microsoft Academic Search

Family 28 glycoside hydrolases (polygalacturonases) are found in organisms across the plant, fungal and bacterial kingdoms, where they are central to diverse biological functions such as fruit ripening, biomass recycling and plant pathogenesis. The structures of several polygalacturonases have been reported; however, all of these enzymes utilize an endo-mode of digestion, which generates a spectrum of oligosaccharide products with varying

D. Wade Abbott; Alisdair B. Boraston

2007-01-01

306

GH97 is a new family of glycoside hydrolases, which is related to the ?-galactosidase superfamily  

Microsoft Academic Search

BACKGROUND: As a rule, about 1% of genes in a given genome encode glycoside hydrolases and their homologues. On the basis of sequence similarity they have been grouped into more than ninety GH families during the last 15 years. The GH97 family has been established very recently and initially included only 18 bacterial proteins. However, the evolutionary relationship of the

Daniil G Naumoff

2005-01-01

307

Two new polyols and a new phenylpropanoid glycoside from the basidiomycete Lactarius deliciosus.  

PubMed

Two new polyols, 3-hydroxymethyl-2-methylenepentane-1,4-diol and 1-methylcyclohexane-1,2,4-triol, and a new phenylpropanoid glycoside, eugenyl 4?-O-acetyl-?-rutinoside, together with seven known steroids (5-11) were isolated from the fruiting bodies of the basidiomycete Lactarius deliciosus. The structures of these compounds were elucidated by the analysis of spectroscopic data. PMID:21946056

Zhou, Zhong-Yu; Tan, Jian-Wen; Liu, Ji-Kai

2011-09-17

308

Phenolic glycosides govern the food selection pattern of willow feeding leaf beetles  

Microsoft Academic Search

The relationship between the food selection of four leaf beetle species (Phratora vitellinae, Plagiodera versicolora, Lochmaea capreae, Galerucella lineola) and the phenolic glycosides of willow (Salix spp.) leaves was tested in laboratory food choice experiments. Four willow species native to the study area (Eastern Finland) and four introduced, cultivated willows were tested.

J. Tahvanainen; R. Julkunen-Tiitto; J. Kettunen

1985-01-01

309

Reversible Flowchart Languages and the Structured Reversible Program Theorem  

Microsoft Academic Search

Many irreversible computation models have reversible counterparts, but these are poorly understood at present. We introduce\\u000a reversible flowcharts with an assertion operator and show that any reversible flowchart can be simulated by a structured reversible\\u000a flowchart using only three control flow operators. Reversible flowcharts are r- Turing-complete, meaning that they can simuluate reversible Turing machines without garbage data. We also

Tetsuo Yokoyama; Holger Bock Axelsen; Robert Glück

2008-01-01

310

Influence of iridoid glycoside containing host plants on midgut ?-glucosidase activity in a polyphagous caterpillar, Spilosoma virginica Fabricius (Arctiidae).  

PubMed

Iridoid glycosides are secondary plant compounds that have deterrent, growth reducing or even toxic effects on non-adapted herbivorous insects. To investigate the effects of iridoid glycoside containing plants on the digestive metabolism of a generalist herbivore, larvae of Spilosoma virginica (Lepidoptera: Arctiidae) were reared on three plant species that differ in their secondary plant chemistry: Taraxacum officinale (no iridoid glycosides), Plantago major (low iridoid glycoside content), and P. lanceolata (high iridoid glycoside content). Midguts of fifth instar larvae were assayed for the activity and kinetic properties of ?-glucosidase using different substrates. Compared to the larvae on T. officinale, the ?-glucosidase activity of larvae feeding on P. lanceolata was significantly lower measured with 4-nitrophenyl-?-d-glucopyranoside. Using the iridoid glycoside aucubin as a substrate, we did not find differences in the ?-glucosidase activity of the larvae reared on the three plants. Heat inactivation experiments revealed the existence of a heat-labile and a more heat-stable ?-glucosidase with similar Michaelis constants for 4-nitrophenyl-?-d-glucopyranoside. We discuss possible mechanisms leading to the observed decrease of ?-glucosidase activity for larvae reared on P. lanceolata and its relevance for generalist herbivores in adapting to iridoid glycoside containing plant species and their use as potential host plants. PMID:20727899

Pankoke, Helga; Bowers, M Deane; Dobler, Susanne

2010-08-26

311

Flavonoid glycosides from the leaves of Cissus ibuensis hook (vitaceae).  

PubMed

The bioactive N-butanol fraction of the ethanol extract of the leaves of Cissus ibuensis was fractionated over silica Gel column to give Quercetin 3-O-rutinoside (I) and mixtures of Flavonoids (A2). A2 was fractionated using reverse phase HPLC to give Kaempferol 3-O-?-rhamnopyranosyl (1?6)-?-D-galactopyranoside (II), Kaempferol 3-O-rutinoside(III) and Kaempferol3-O-?-rhamnopyranosyl (1?6)-?-rhamnopyranosyl(1?2)-?-D-galactopyranoside (IV). The structures were elucidated by NMR spectroscopy and compared with literature. PMID:21461150

Ahmadu, A A; Onanuga, A; Aquino, R

2010-04-03

312

Supplementing with non-glycoside hydrolase proteins enhances enzymatic deconstruction of plant biomass.  

PubMed

The glycoside hydrolases (GH) of Caldicellulosiruptor bescii are thermophilic enzymes, and therefore they can hydrolyze plant cell wall polysaccharides at high temperatures. Analyses of two C. bescii glycoside hydrolases, CbCelA-TM1 and CbXyn10A with cellulase and endoxylanase activity, respectively, demonstrated that each enzyme is highly thermostable under static incubation at 70°C. Both enzymes, however, rapidly lost their enzymatic activities when incubated at 70°C with end-over-end shaking. Since crowding conditions, even at low protein concentrations, seem to influence enzymatic properties, three non-glycoside hydrolase proteins were tested for their capacity to stabilize the thermophilic proteins at high temperatures. The three proteins investigated were a small heat shock protein CbHsp18 from C. bescii, a histone MkHistone1 from Methanopyrus kandleri, and bovine RNase A, from a commercial source. Fascinatingly, each of these proteins increased the thermostability of the glycoside hydrolases at 70°C during end-over-end shaking incubation, and this property translated into increases in hydrolysis of several substrates including the bioenergy feedstock Miscanthus. Furthermore, MkHistone1 and RNase A also altered the initial products released from the cello-oligosaccharide cellopentaose during hydrolysis with the cellodextrinase CbCdx1A, which further demonstrated the capacity of the three non-GH proteins to influence hydrolysis of substrates by the thermophilic glycoside hydrolases. The non-GH proteins used in the present report were small proteins derived from each of the three lineages of life, and therefore expand the space from which different polypeptides can be tested for their influence on plant cell wall hydrolysis, a critical step in the emerging biofuel industry. PMID:22952777

Su, Xiaoyun; Zhang, Jing; Mackie, Roderick I; Cann, Isaac K O

2012-08-27

313

Azido glycoside primer: a versatile building block for the biocombinatorial synthesis of glycosphingolipid analogues.  

PubMed

A lactoside primer, 12-azidododecyl beta-lactoside, was synthesized via the Koenigs-Knorr method by glycosylation of 1,12-dodecyldiol with perbenzoylated lactosyl bromide. The presence of the 2-O-acyl substituent in the donor gave the beta-lactoside, and an excess of acceptor ensured monoglycosylation of the diol. Mesylation of the omega-hydroxyl group in the aglycon, followed by displacement of the mesylate with azide and subsequent O-debenzoylation gave the desired omega-azidododecyl beta-lactoside. The azido glycoside primer was examined in mouse B16 melanoma cells for its feasibility as a building block for oligosaccharide biosynthesis. Uptake of the azido glycoside primer by B16 cells resulted in the sialylation of the galactose residue of the primer to give a glycosylated product having the same glycan as in ganglioside GM3. After 24 h incubation of B16 cells with the primers, the amount of sialylated omega-azidododecyl beta-lactoside primer was 75% of the amount of sialylated n-dodecyl beta-lactoside. However, after 48 h incubation, both primers gave equal amounts of the sialylated products. Interestingly, the remaining azido glycoside primer after 48 h incubation was 5.6-fold greater than that of the alkyl primer, indicating degradation of the alkyl primer to a larger extent than the omega-azido glycoside primer. The facile chemical synthesis and the efficient uptake in cells make the azido glycoside primer a versatile building block for the biocombinatorial synthesis of glycolipid oligosaccharides. PMID:11125817

Kasuya, M C; Wang, L X; Lee, Y C; Mitsuki, M; Nakajima, H; Miura, Y; Sato, T; Hatanaka, K; Yamagata, S; Yamagata, T

2000-12-01

314

["Reversible" dementia in 2011].  

PubMed

Reversible dementias are rare and account for approximately 1.5% of all dementias. The most frequent etiology is represented by neurosurgical causes such as benign tumours, adult chronic hydrocephalus (so-called « normal pressure » hydrocephalus) or subdural hematoma, which are easily revealed by neuroimaging. Systematic ancillary investigations aimed at detecting an infectious disease (syphilis, HIV infection, Lyme neuroborreliosis or, more rarely, Whipple disease), an endocrine aetiology or a vitamin deficiency are rarely contributory, but remain relevant since these dementias could be reversible. Discovering a reversible cause of dementia does not always allow full recovery after treatment. However, systematic ancillary investigations can identify and treat concomitant reversible conditions, which contribute to worsening the main clinical condition in nearly 25% of dementia cases. PMID:21690030

Michel, Jean-Marc; Sellal, François

2011-06-01

315

Reversible Inactivation of Dehydrogenases.  

National Technical Information Service (NTIS)

The reversible dissociation of lactic and malic dehydrogenases has been studied in detail and compared with the dissociation properties of triosephosphate dehydrogenase, alpha-glycerophosphate dehydrogenase, and liver alcohol dehydrogenase. Evidence is pr...

O. P. Chilson G. B. Kitto J. Pudles N. O. Kaplan

1965-01-01

316

Reverse Osmosis Application Studies.  

National Technical Information Service (NTIS)

To assess the feasibility of applying reverse osmosis (RO) and ultrafiltration (UF) for effective treatment of process and waste streams from operations at Ontario Hydro's thermal and nuclear stations, an extensive literature survey has been carried out. ...

A. Golomb

1982-01-01

317

Reversing Axial Blower.  

National Technical Information Service (NTIS)

The development and operating characteristics of a reversing axial blower are described. The operating K-84 rotor was used for the first stage and the components of the system were designed with consideration of the characteristics of the drive.

I. V. Brusilovski I. V. Klepakov E. M. Levin

1966-01-01

318

Reverse Osmosis Technical Manual.  

National Technical Information Service (NTIS)

A comprehensive design manual was compiled for reverse osmosis systems suitable for use by consulting engineers and others actively involved in water supply and improvement for municipal water systems. The manual includes chapters on semipermeable membran...

1979-01-01

319

On thermodynamic and microscopic reversibility  

SciTech Connect

The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa.

Crooks, Gavin E.

2011-07-12

320

Seasonal variation of alkaloids of Adhatoda vasica and detection of glycosides and N-Oxides of vasicine and vasicinone.  

PubMed

The distribution pattern of the alkaloids of A. Vasica has been studied with change of season. The study also resulted in the detection of glycosides and N-oxides of vasicine and vasicinone. PMID:17404955

Pandita, K; Bhatia, M S; Thappa, R K; Agarwal, S G; Dhar, K L; Atal, C K

1983-06-01

321

Identification and quantitation of glycosidically bound aroma compounds in three tobacco types by gas chromatography-mass spectrometry.  

PubMed

Glycosidically bound aroma compounds in three different types of tobacco were investigated. After isolation of extracts obtained by Amberlite XAD-2 adsorption and ethyl acetate elution, glycosides were analyzed after enzymatic hydrolysis by gas chromatography-mass spectrometry (GC-MS) or directly after trifluoroacetylated (TFA) derivatization by GC-MS in electron ionization (EI) and negative chemical ionization (NCI) mode. In total 21 bound aglycones were identified by ?-glucosidase hydrolysis. These aglycones mainly consisted of C13-norisoprenoids, aromatic components and sesquiterpenoids. Additionally, with the aid of enzymatic hydrolysis, 15 ?-d-glucopyranosides and 1 ?-d-rutinoside were tentatively identified by TFA derivatization. TFA method was validated by repeatability and successfully employed to analyze different types of tobacco. Principal component analysis (PCA) was carried out on identified glycoside variables to visualize the difference between the tobacco types and the relationship between the glycoside variables and the tobacco types was established. PMID:24011421

Cai, Kai; Xiang, Zhangmin; Pan, Wenjie; Zhao, Huina; Ren, Zhu; Lei, Bo; Geng, Zhaoliang

2013-08-21

322

[Adaptogenic effects of furostanol glycosides of Dioscorea deltoidea wall on oxidative processes in tomato plants in biotic stress].  

PubMed

The effect of furostanol glycosides of cell culture of Dioscorea deltoidea Wall on oxidative processes in tomato plants subjected to invasion with the gall nematode Meloidogyne incognita Kofoid et White was studied. We showed that furostanol glycosides induce a nonspecific defensive response in plants. Exposure of cell membranes to furostanol glycosides cause rearrangements in fatty acids resulting in the formation of conjugated dienes, which makes molecules thermodynamically more stable under stress conditions. The study of changes in the activity of peroxidases of intact plants and plants affected with the nematode, which were treated with furostanol glycosides, showed that the protective effect of the guaiacol-dependent peroxidase is more long-term than the effect of the benzidine-dependent peroxidase. PMID:15977797

Vasil'eva, I S; Vaniushkin, S A; Zinov'eva, S V; Udalova, Zh V; Volkova, L A; Nosov, A M; Paseshnichenko, V A

323

Reversible adaptive trees.  

PubMed

We describe reversible adaptive trees, a class of stochastic algorithms modified from the formerly described adaptive trees. They evolve in time a finite subset of an ambient Euclidean space of any dimension, starting from a seed point and, accreting points to the evolving set, they grow branches towards a target set which can depend on time. In contrast with plain adaptive trees, which were formerly proven to have strong convergence properties to a static target, the points of reversible adaptive trees are removed from the tree when they have not been used recently enough in a path from the root to an accreted point. This, together with a straightening process performed on the branches, permits the tree to follow some moving targets and still remain adapted to it. We then discuss in what way one can see such reversible trees as a model for a qualitative property of resilience, which leads us to discuss qualitative modeling. PMID:23934230

Kergosien, Yannick L

2013-08-10

324

Reversible Chemical Kinetics Model  

NSDL National Science Digital Library

The Reversible Chemical Kinetics Model illustrates the time evolution of a reversible chemical reaction, from a given set of initial reactants concentration until chemical equilibrium is reached. The concentrations are plotted against time and the respective numerical values are periodically displayed at the data Table. As chemical equilibrium is attained, the concentrations become constant, the reaction quotient (Q) equalizes the equilibrium constant and Gibbs's energy change (G/RT) approaches zero. The Reversible Chemical Kinetics Model was developed using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the jar file will run the program if Java is installed. You can modify this simulation if you have EJS installed by right-clicking within the map and selecting "Open Ejs Model" from the pop-up menu item.

Fernandes, Fernando S.

2012-10-20

325

Structurally different flavonol glycosides and hydroxycinnamic acid derivatives respond differently to moderate UV-B radiation exposure.  

PubMed

The aim of this study was to investigate the modifying influence of moderate ultraviolet-B (UV-B) radiation exposure on structurally different flavonol glycosides and hydroxycinnamic acid derivatives during pre-harvest using kale, a leafy Brassica species with a wide spectrum of different non-acylated and acylated flavonol glycosides. Juvenile kale plants were treated with short-term (1 day), moderate UV-B radiation [0.22-0.88 kJ m?˛ day?ą biologically effective UV-B (UV-B(BE))]. Twenty compounds were quantified, revealing a structure-specific response of flavonol glycosides and hydroxycinnamic acid derivatives to UV-B radiation. A dose- and structure-dependent response of the investigated phenolic compounds to additional UV-B radiation was found. The investigated quercetin glycosides decreased under UV-B; for kaempferol glycosides, however, the amount of sugar moieties and the flavonol glycoside hydoxycinnamic acid residue influenced the response to UV-B. Monoacylated kaempferol tetraglucosides decreased in the investigated UV-B range, whereas the monoacylated kaempferol diglucosides increased strongly with doses of 0.88 kJ m?˛ day?ą UV-B(BE) . The UV-B-induced increase in monoacylated kaempferol triglucosides was dependent on the acylation pattern. Furthermore, the hydroxycinnamic acid glycosides disinapoyl-gentiobiose and sinapoyl-feruloyl-gentiobiose were enhanced in a dose-dependent manner under UV-B. While UV-B radiation treatments often focus on flavonol aglycones or total flavonols, our investigations were extended to structurally different non-acylated and acylated glycosides of quercetin and kaempferol. PMID:22292604

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

2012-02-01

326

Chemical composition and antioxidant effect of glycosidically bound volatile compounds from oregano ( Origanum vulgare L. ssp. hirtum)  

Microsoft Academic Search

The present work examines the content and chemical composition of the glycosidically bound volatiles from oregano as well as their antioxidative properties. The glycosidically bound volatiles amounted to 20 mg kg?1 in dried leaves and flowers of oregano. Fourteen volatile aglycones were identified with thymoquinone as the major component. Other important aglycones were benzyl alcohol, eugenol, 2-phenyl-ethanol, thymol, 3-hexen-1-ol and

M Milos; J Mastelic; I Jerkovic

2000-01-01

327

Effect of new rotenoid glycoside from the fruits of Amorpha fruticosa LINNE on the growth of human immune cells  

Microsoft Academic Search

A new compound, rotenoid isoflavone glycoside named, 6?-O-?-d-glucopyranosyl-12a-hydroxydalpanol was isolated from the methanolic (MeOH) fruit extract of Amorpha fruticosa LINNE by means of multi-stage column chromatography. Immuno-modulatory activities of this new glycoside were compared with\\u000a the partitioned fractions of Amorpha fruticosa LINNE. Both of the fractions and purified single compound showed a 19% relatively low cytotoxicity at a maximum concentration

Hak Ju Lee; Ha Young Kang; Cheol Hee Kim; Hyo Sung Kim; Min Chul Kwon; Sang Moo Kim; Il Shik Shin; Hyeon Yong Lee

2006-01-01

328

Identification of the Catalytic Residues in Family 52 Glycoside Hydrolase, a  Xylosidase from Geobacillus stearothermophilus T-6  

Microsoft Academic Search

-D-Xylosidases (EC 3.2.1.37) are exo-type glycoside hy- drolases that hydrolyze short xylooligosaccharides to xylose units. The enzymatic hydrolysis of the glycosidic bond involves two carboxylic acid residues, and their identification, together with the stereochemistry of the reaction, provides crucial information on the catalytic mechanism. Two catalytic mutants of a -xylosidase from Geobacillus stearothermophilus T-6 were subjected to detailed kinetic analysis

Tsafrir Bravman; Valery Belakhov; Dmitry Solomon; Gil Shoham; Bernard Henrissat; Timor Baasov; Yuval Shoham

2003-01-01

329

Molluscicidal activity of cardiac glycosides from Nerium indicum against Pomacea canaliculata and its implications for the mechanisms of toxicity  

Microsoft Academic Search

Cardiac glycosides from fresh leaves of Nerium indicum were evaluated for its molluscicidal activity against Pomacea canaliculata (golden apple snail: GAS) under laboratory conditions. The results showed that LC50 value of cardiac glycosides against GAS was time dependent and the LC50 value at 96h was as low as 3.71mg\\/L, which was comparable with that of metaldehyde at 72h (3.88mg\\/L). These

Lingpeng Dai; Wanxian Wang; Xinjiao Dong; Renyong Hu; Xuyang Nan

2011-01-01

330

Dynamics of magnetization reversal  

NASA Astrophysics Data System (ADS)

Advanced magnetic recording systems are designed for extremely high areal densities and data rate. These two aspects require both magnetization reversal at very short times (< 1 ns) and long term ( ~ 5-10 years) stability against thermal fluctuations. There are two basic physics problems associated with these requirements. The first is a characterization of thermal-dynamic reversal over very wide time range. The second is an understanding of the physics of the relaxation mechanisms. Both these subjects will be reviewed in this talk. Thermal dynamic reversal requires solution of the Landau-Lifshitz equation with fluctuations. We have solved this problem in terms of the ``random walk" dynamics of a nonlinear oscillator [1,2]. The expressions for the switching field versus pulse time are analytic and show good agreement with measurements on CrO_2. Our studies of fundamental relaxation mechanisms have involved a two step approach. First the results of computer simulations of magnetization reversal without phenomenological damping will be discussed. In this case coherent rotation of the magnetization excites spin waves during which an excess of Zeeman energy is transformed to anisotropy and exchange energies. However, for fine grains whose size is sufficiently small so that the grain magnetization is virtually uniform, non-linear spin waves cannot assist reversal [3]. A new analytic model of reversal that couples coherent rotation to impurity ions by an anisotropic exchange mechanism will be discussed. These impurity ions are assumed to relax at a very high rate to the lattice. [1] V.L.Safonov, JMMM 195, 523 (1999); J.Appl.Phys. 85, 4370 (1999). [2] V.L.Safonov, H.N.Bertram, MMM'99, CU-09. [3] V.L.Safonov, H.N.Bertram, J.Appl.Phys. 85, 5072 (1999); MMM'99, CD-11.

Safonov, Vladimir L.

2000-03-01

331

Reverse logistics network: A review  

Microsoft Academic Search

As the fundamental and strategic issue in reverse logistics, reverse logistics network has become one of the academic research focuses. This paper gives a literature review on reverse logistics network researches in the last decade, and summarizes the research output of two major methodologies: case study and quantity model. This paper further classifies the numerous reverse logistic network models as

Zheng Wang; Hua Bai

2010-01-01

332

Reverse shoulder arthroplasty.  

PubMed

The reverse shoulder arthroplasty is considered to be one of the most significant technological advancements in shoulder reconstructive surgery over the past 30 years. It is able to successfully decrease pain and improve function for patients with rotator cuff-deficient shoulders. The glenoid is transformed into a sphere that articulates with a humeral socket. The current reverse prosthesis shifts the center of rotation more medial and distal, improving the deltoid's mechanical advantage. This design has resulted in successful improvement in both active shoulder elevation and in quality of life. PMID:23827841

Jarrett, Claudius D; Brown, Brandon T; Schmidt, Christopher C

2013-04-29

333

Flavonol glycosides from Montcalm dark red kidney bean: implications for the genetics of seed coat color in Phaseolus vulgaris L.  

PubMed

Three flavonol glycosides were isolated and identified from the commercial dark red kidney bean (Phaseolus vulgaris L.) cultivar Montcalm. In order of highest to lowest concentration these compounds were 3',4',5,7-tetrahydroxyflavonol 3-O-beta-D-glucopyranosyl (2-->1) O-beta-D-xylopyranoside (compound 1), quercetin 3-O-beta-D-glucopyranoside (compound 2), and kaempferol 3-O-beta-D-glucopyranoside (compound 3). Compound 1 is a flavonol glycoside that has not been reported before in P. vulgaris L. These three flavonol glycosides were yellow compounds that do not contribute to the garnet red color of Montcalm seed coats. Red-colored compounds which tested positive for proanthocyanidins are most likely responsible for the red seed coat color of Montcalm. Previous work on the chemistry of the compounds produced from the multi-allelic seed coat gene series C-C(r)()-c(u) indicated that neither anthocyanins nor flavonol glycosides were detected from seed coat extracts in the presence of the c(u)() locus. However, the seed coat color genotype of Montcalm is c(u) J g B v rk(d) and three flavonol glycosides were found. Technological advances such as modern HPLC analysis of seed coat extracts may allow for detection of small amounts of compounds which previously could not be seen using paper chromatography. Alternatively, the change of the Rk allele to rk(d) may allow for the synthesis of flavonol glycosides in the presence of c(u). PMID:10552769

Beninger, C W; Hosfield, G L

1999-10-01

334

Cucurbitane-type triterpene glycosides from the fruits of Momordica charantia.  

PubMed

Phytochemical investigation of the fruits of Momordica charantia resulted in the isolation and characterization of two new (1 and 2) and eight known cucurbitane-type triterpene glycosides and one cucurbitane-type triterpene. The glycosides (7beta,25-dimethoxycucurbita-5(6),23( E)-dien-19-al 3- O-beta-D-allopyranoside (1); 25-methoxycucurbita-5(6),23(E)-dien-19-ol 3-O-beta-D-allopyranoside (2); momordicosides A, F (1), F (2), G, K, and L; and goyaglycoside-c and goyaglycoside-d) and the triterpene [3 beta,7 beta,25-trihydroxycucurbita-5,23(E)-dien-19-al] were characterized by physical, chemical, and spectroscopic techniques, including 1D- and 2D-NMR as well as by comparison with the reported data. PMID:18622906

Liu, Yi; Ali, Zulfiqar; Khan, Ikhlas A

2008-07-11

335

Antiviral isoflavonoid sulfate and steroidal glycosides from the fruits of Solanum torvum.  

PubMed

The C-4 sulfated isoflavonoid, torvanol A (1), and the steroidal glycoside, torvoside H (3), together with the known glycoside, torvoside A (2), were isolated from a MeOH extract of Solanum torvum fruits. Upon enzymatic hydrolysis with beta-glucosidase, torvoside A (2) and torvoside H (3) yielded the corresponding acetal derivatives 4 and 5, respectively. Torvanol A (1), torvoside H (3) and compound 5 exhibited antiviral activity (herpes simplex virus type 1) with IC(50) values of 9.6, 23.2 and 17.4 microg/ml, respectively. Compounds 1-5 showed no cytotoxicity (at 50 microg/ml) against BC, KB and Vero cell lines. PMID:11830167

Arthan, Damrongkiet; Svasti, Jisnuson; Kittakoop, Prasat; Pittayakhachonwut, Daraporn; Tanticharoen, Morakot; Thebtaranonth, Yodhathai

2002-02-01

336

7-O-methylkaempferol and -quercetin glycosides from the whole plant of Nervilia fordii.  

PubMed

Five new 7-O-methylkaempferol and -quercetin glycosides, namely, nervilifordins A-E (1-5), were isolated from the whole plant of Nervilia fordii, together with seven known flavonoids (6, 7, and 9-13) and one known coumarin (8). Their structures were elucidated on the basis of extensive spectroscopic analyses, including HSQC, HMBC, ROESY, and chemical methods. Compounds 1-3 and 6-13 were evaluated for their anti-herpes simplex virus 1 (HSV-1) activity and cytotoxicity on African green monkey kidney cells (Vero cells) in vitro. Of the tested compounds, only esculetin (8) exhibited antiviral activity against HSV-1, while the aglycones (11-13) showed stronger cytotoxicity on Vero cells than their glycosides (1-3, 6, and 7). PMID:19422205

Tian, Li-Wen; Pei, Ying; Zhang, Ying-Jun; Wang, Yi-Fei; Yang, Chong-Ren

2009-06-01

337

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

PubMed

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-?-L-arabinoside-7-O-?-D-glucoside (1), isorhamnetin-3-O-?-D-glucoside (2), dibutyl phthalate (3), (+)-1-hydroxylpinoresinol-4'-?-D-glucoside (4), pinoresinol-4'-O-?-D-glucoside (5) and 2-phenylethyl-?-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. PMID:22510608

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

2012-04-17

338

[Pharmacological activity of dihydroflavonol glycoside isolated from the plant Eupatorium micranthum Less].  

PubMed

The aim of the work was the investigation of pharmacological activity of unique dihydroflavonol glycoside, micranthoside, extracted from the leaves Eupatorium micranthum Less. introduced into Georgia. Mature human T-cell leukemia cell lines (Jurkat) were analyzed in the study under the modeled oxidative stress. For modelling of oxidative stress 30% hydrogen peroxide (H(2)O(2)) (Sigma) (100 microM) was added to Jurkat cell incubation suspension with subsequent incubation for 24, 48 h. Under the effect of H(2)O(2) there was significant elevation of superoxide and peroxyl radical levels, as well as free NO levels, and reduced antioxidant enzyme SOD activity. It was shown that dihydroflavonol glycoside, micranthoside, extragated from Eupatorium micranthum Less., has marked antioxidant properties, it inhibits hyperproduction of reactive oxygen species, and protects cells against oxidative damage, stimulates cell proliferation and inhibits necrosis in cell line. PMID:18487695

Sagare?shvili, T G; Mikautadze, M M; Intskirveli, N A; Enukidze, M G; Machavariani, M G

2008-04-01

339

A phenylpropanoid glycoside with antioxidant activity from Picria tel-ferae.  

PubMed

A phytochemical study on Picria tel-ferae resulted in the isolation of a phenylpropanoid glycoside (1), which was reported for the first time from this plant. The structure of compound 1 was identified as 1-O-3,4-(dihydroxyphenyl)- ethyl-beta-D- apiofuranosyl- (1-->4)-alpha-L-rharmnopyranosyl- (1-->3)-4-O-caffeoyl- beta-D-glucopyranoside on the basis of spectroscopic analyses. In addition, it was found that 1 exhibited a remarkable inhibitory effect on lipid peroxidation initiated by either a free radical [AAPH; 2,2'-azobis-(2-amidinopropane)dihydrochloride] or generated hydroxyl radical (Fe2+/ascorbate). These findings, together with those of previous studies, suggest that P. tel-ferae possesses abundant phenylpropanoid glycosides, and the plant might be used beneficially in the treatment of oxidative stress-related human diseases. PMID:17958321

Thuan, Nguyen Duy; Ha, Do Thi; Thuong, Phuong Thien; Na, Min Kyun; Lee, Jong Pill; Lee, Jeong-Hun; Seo, Hyo-Won; Min, Byung-Sun; Kim, Jin-Cheol; Bae, KiHwan

2007-09-01

340

Tyrosinase inhibition studies of cycloartane and cucurbitane glycosides and their structure-activity relationships.  

PubMed

In the present paper, tyrosinase inhibition studies and structure-activity relationship of eight cycloartane glycosides and one cucurbitane glycoside and its genin, which were isolated from Astragalus (Leguminoseae) and Bryonia (Cucurbitaceae) plants, have been discussed. The activities are compared with two reference tyrosinase inhibitors, kojic acid and l-mimosine. These studies and the SAR showed that the askendoside B which exhibited highly potent (IC50 =13.95 microM) tyrosinase inhibition could be a possible lead molecule for the development of new medications of several skin diseases related with the over-expression of the enzyme tyrosinase, like hyperpigmentation. The molecule also may be interesting for the cosmetic industries as a skin whitening agent. PMID:16716596

Khan, Mahmud Tareq Hassan; Choudhary, M Iqbal; Atta-ur-Rahman; Mamedova, Reyhan P; Agzamova, Manzura A; Sultankhodzhaev, Mukhlis N; Isaev, Mahamed I

2006-05-23

341

Flavone C-glycosides from the leaves of Lophatherum gracile and their in vitro antiviral activity.  

PubMed

Four new flavone C-glycosides, luteolin 6-C-?-L-arabinopyranosyl-7-O-?-D-glucopyranoside, apigenin 6-C-?-D-galactopyranosiduronic acid (1???2)-?-L-arabinopyranoside, luteolin 6-C-?-D-galactopyranosiduronic acid (1???2)-?-L-arabinopyranoside, and luteolin 6-C-?-D-glucopyranosiduronic acid (1???2)-?-L-arabinofuranoside, along with three known ones, were isolated from the leaves of Lophatherum gracile. The structures of the new compounds were elucidated by extensive spectroscopic methods as well as acid hydrolysis. All the flavone glycosides isolated from this plant were screened for their in vitro antiviral activity against respiratory syncytial virus (RSV) with cytopathic effect (CPE) reduction assay, and several flavone 6-C-monoglycosides showed potent in vitro anti-RSV effect. PMID:21870321

Wang, Ying; Chen, Mei; Zhang, Jing; Zhang, Xiao-Li; Huang, Xiao-Jun; Wu, Xin; Zhang, Qing-Wen; Li, Yao-Lan; Ye, Wen-Cai

2011-08-25

342

Novel acetylated chalcone and biflavonoid glycosides from Trigonosciadium brachytaenium (Boiss.) Alava.  

PubMed

A new acetylated chalcone glycoside, trans-2',6'-dihydroxy-4'-O-(4?-acetyl-rhamnoside)-4-methoxychalcone (1) and a new biflavonoid glycosides, 5,3',5?,4?'-tetrahydroxy-3?',5?'dimethoxy-biflavone (4' ? 8?)-7-O-((2-rhamnoside) rhamnoside) (2) were isolated from the ethyl acetate soluble fraction of the methanol extract obtained from Trigonosciadium brachytaenium and have been purified by column chromatography and preparative TLC. Those structures were elucidated by UV, (1)H NMR and (13)C NMR, HMBC, EI-MS and IR spectra. The antioxidant activity of ethyl acetate extract was evaluated by 1,1-diphenyl-2-picrylhydrazyl method. The results indicate that ethyl acetate extract from aerial part of T. brachytaenium possesses considerable antioxidant activity. PMID:23631351

Akhavan, Malihe; Shafaghat, Ali; Salimi, Farshid

2013-04-30

343

Fluorogenic sialic acid glycosides for quantification of sialidase activity upon unnatural substrates.  

PubMed

Herein we report the synthesis of N-acetyl neuraminic acid derivatives as 4-methylumbelliferyl glycosides and their use in fluorometrically quantifying human and bacterial sialidase activity and substrate specificities. We found that sialidases in the human promyelocytic leukemic cell line HL60 were able to cleave sialic acid substrates with fluorinated C-5 modifications, in some cases to a greater degree than the natural N-acetyl functionality. Human sialidases isoforms were also able to cleave unnatural substrates with bulky and hydrophobic C-5 modifications. In contrast, we found that a bacterial sialidase isolated from Clostridium perfringens to be less tolerant of sialic acid derivatization at this position, with virtually no cleavage of these glycosides observed. From our results, we conclude that human sialidase activity is a significant factor in sialic acid metabolic glycoengineering efforts utilizing unnatural sialic acid derivatives. Our fluorogenic probes have enabled further understanding of the activities and substrate specificities of human sialidases in a cellular context. PMID:23639536

Zamora, Cristina Y; d'Alarcao, Marc; Kumar, Krishna

2013-04-10

344

Production of Hesperetin Glycosides by Xanthomonas campestris and Cyclodextrin Glucanotransferase and Their Anti-allergic Activities  

PubMed Central

The production of hesperetin glycosides was investigated using glycosylation with Xanthomonas campestris and cyclodextrin glucanotransferase (CGTase). X. campestris glucosylated hesperetin to its 3'-, 5-, and 7-O-glucosides, and CGTase converted hesperetin glucosides into the corresponding maltosides. The resulting 7-O-glucoside and 7-O-maltoside of hesperetin showed inhibitory effects on IgE antibody production and on O2- generation from rat neutrophils.

Shimoda, Kei; Hamada, Hiroki

2010-01-01

345

Cloning, Expression and Characterization of a Glycoside Hydrolase Family 39 Xylosidase from Bacillus Halodurans C-125  

Microsoft Academic Search

The gene encoding a glycoside hydrolase family 39 xylosidase (BH1068) from the alkaliphile Bacillus halodurans strain C-125 was cloned with a C-terminal His-tag, and the recombinant gene product termed BH1068(His)6 was expressed in Escherichia coli. Of the artificial substrates tested, BH1068(His)6 hydrolyzed nitrophenyl derivatives of ?-d-xylopyranose, ?-l-arabinofuranose, and ?-l-arabinopyranose. Deviation from Michaelis?Menten kinetics at higher substrate concentrations indicative of transglycosylation

Kurt Wagschal; Diana Franqui-Espiet; Charles C. Lee; George H. Robertson; Dominic W. S. Wong

2008-01-01

346

Cloning, Expression and Characterization of a Glycoside Hydrolase Family 39 Xylosidase from Bacillus Halodurans C-125  

Microsoft Academic Search

The gene encoding a glycoside hydrolase family 39 xylosidase (BH1068) from the alkaliphile Bacillus halodurans strain C-125 was cloned with a C-terminal His-tag, and the recombinant gene product termed BH1068(His)6 was expressed in Escherichia coli. Of the artificial substrates tested, BH1068(His)6 hydrolyzed nitrophenyl derivatives of ?-d-xylopyranose, ?-l-arabinofuranose, and ?-l-arabinopyranose. Deviation from Michaelis-Menten kinetics at higher substrate concentrations indicative of transglycosylation

Kurt Wagschal; Diana Franqui-Espiet; Charles C. Lee; George H. Robertson; Dominic W. S. Wong

2008-01-01

347

A New BioActive Flavonol Glycoside from the Stems of Butea superba Roxb  

Microsoft Academic Search

A new bio-active flavonol glycoside was isolated from the stems of Butea superba Roxb, and its structure was determined by spectral analysis and chemical degradations as 3,5,7,3?,4?-pentahydroxy-8-methoxy-flavonol-3-O-?-D-xylopyranosyl(1 ? 2)-?-L-rhamnopyranoside. The compound 1 showed antimicrobial activity against plant pathogenic fungi Trich viride, Asprgillus fumigatus, A. niger, A. terreus, Penicillium expansum, Helmitnhosporium oryzae, Botxitis cinerea, Rhizopus oligosporus, R. chinensis, Kelbsiella pneumoniae, Fusearium

R. N. Yadava; K. I. S. Reddy

1998-01-01

348

The Chameleon of Retaining Glycoside Hydrolases and Retaining Glycosyl Transferases: The Catalytic Nucleophile  

Microsoft Academic Search

Summary.  ?This paper addresses the existence and role of a catalytic nucleophile in retaining glycoside hydrolases and retaining glycosyl\\u000a transferases. Although the former has now been established beyond doubt, such is not the case with the latter. We report reliable\\u000a procedures for the synthesis of various 2-deoxy-2-fluoro glycosyl nucleoside diphosphates, useful donor analogues for the\\u000a study of the mechanism of action

Robert V. Stick; Andrew G. Watts

2002-01-01

349

Spirostanol and furostanol glycosides from the fresh tubers of Polianthes tuberosa.  

PubMed

Six new steroid glycosides--two spirostanols, polianthosides B and C (1, 2), and four furostanols, polianthosides D-G (3-6)--were isolated from the fresh tubers of Polianthes tuberosa, together with seven known spirostanols (7-13) and a known furostanol (14) saponins. Their structures were elucidated on the basis of spectroscopic analysis and the results of acidic and enzymatic hydrolysis. The cytotoxic activities of 1-14 against HeLa cells are reported. PMID:14738376

Jin, Jian-Ming; Zhang, Ying-Jun; Yang, Chong-Ren

2004-01-01

350

Isolation and structure elucidation of three glycosides and a long chain alcohol from Polianthes tuberosa Linn.  

PubMed

Three glycosides and a long chain alcohol were isolated from the bulbs of Polianthes tuberosa, these were identified as 3,29-dihydroxystigmast-5-ene-3-O-beta-D-galactopyranoside (1), ethyl beta-D-galactopyranoside (2), ethyl-alpha-D-galactopyranoside (3), and 1-tricosanol (4). The structures were determined by extensive spectroscopic and chemical methods. All four isolated compounds were screened for their cytotoxicity, antibacterial and antifungal activities, none of the compounds showed any significant activity. PMID:12168766

Kha, Khalid Mohammed; Perveen, Shahnaz; Ayattollahi, S Abdul Majid; Saba, Nikhat; Rashid, Adil; Firdous, Sadiqa; Haider, Syed Moazzam; Ullah, Zia; Rahat, Shagufta; Khan, Zarrar

2002-08-01

351

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

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

352

Bioactive monoterpene glycosides conjugated with gallic acid from the leaves of Eucalyptus globulus  

Microsoft Academic Search

Two monoterpene glycosides, conjugated with gallic acid [globulusin A (1) and B (2)], together with four known compounds, cypellocarpin A (3), eucaglobulin (4), cuniloside (5) and (1S, 2S, 4R)-trans-2-hydroxy-1,8-cineole ?-d-glucopyranoside (6), were isolated from hot-water extracts of the leaves of Eucalyptus globulus. The structures of compounds 1 and 2 were determined by 1D, 2D NMR and MS spectroscopic analyses. The

Tatsuya Hasegawa; Fumihide Takano; Takanobu Takata; Masato Niiyama; Tomihisa Ohta

2008-01-01

353

Characterization and content of flavonoid glycosides in genetically modified tomato (Lycopersicon esculentum) fruits.  

PubMed

There is a growing interest in producing food plants with increased amounts of flavonoids because of their potential health benefits. Tomatoes contain small amounts of flavonoids, most of which are located in the peel of the fruit. It has been shown that flavonoid accumulation in tomato flesh, and hence an overall increase in flavonoid levels in tomato fruit, can be achieved by means of simultaneous overexpression of the maize transcription factors LC and C1. Fruit from progeny of two modified lines (2027 and 2059) was selected for a detailed analysis and individual identification of flavonoids, at different stages of maturity. Nine major flavonoids were detected in the flesh of transgenic ripe tomatoes. LC/NMR, LC/MS, and LC/MS/MS enabled us to identify these as kaempferol-3,7-di-O-glucoside (1), kaempferol-3-O-rutinoside-7-O-glucoside (2), two dihydrokaempferol-O-hexosides (3 and 4), rutin (5), kaempferol-3-O-rutinoside (6), kaempferol-3-O-glucoside (7), naringenin-7-O-glucoside (8) and naringenin chalcone (9), which were quantified by HPLC/DAD. All but 5, 6, and 9 were detected in tomato for the first time. The total flavonoid glycoside content of ripe transgenic tomatoes of line 2059 was about 10-fold higher than that of the controls, and kaempferol glycosides accounted for 60% of this. Kaempferol glycosides comprised around 5% of the flavonoid glycoside content of ripe control tomatoes (the rest was rutin and naringenin chalcone). The rutin concentration in both transgenic and control fruits was similar. PMID:12696918

Le Gall, Gwénaëlle; DuPont, M Susan; Mellon, Fred A; Davis, Adrienne L; Collins, Geoff J; Verhoeyen, Martine E; Colquhoun, Ian J

2003-04-23

354

UNBS1450, a steroid cardiac glycoside inducing apoptotic cell death in human leukemia cells  

Microsoft Academic Search

Cardiac steroids are used to treat various diseases including congestive heart failure and cancer. The aim of this study was to investigate the anti-leukemic activity of UNBS1450, a hemi-synthetic cardenolide belonging to the cardiac steroid glycoside family. Here, we report that, at low nanomolar concentrations, UNBS1450 induces apoptotic cell death. Subsequently, we have investigated the molecular mechanisms leading to apoptosis

Tom Juncker; Claudia Cerella; Marie-Hélčne Teiten; Franck Morceau; Marc Schumacher; Jenny Ghelfi; François Gaascht; Michael Schnekenburger; Estelle Henry; Mario Dicato; Marc Diederich

2011-01-01

355

Ginsenoside Rs 3 , a genuine dammarane-glycoside from Korean red ginseng  

Microsoft Academic Search

A genuine dammarane-glycoside, named as ginsenoside Rs3, was isolated from the MeOH extracts of Korean red ginseng (Panax ginseng C.A. Meyer) through repeated silica gel column chromatographies and its chemical structure was determined as (20S)-protopanaxadiol 3-O-[6?-O-acetyl-?-D-glucopyranosyl (1?2)-?-D-glucopyranoside on the basis of several spectral and physical evidences including HMBC\\u000a and FAB-MS.

Nam-In Baek; Jong Moon Kim; Jeong Hill Park; Jae Ha Ryu; Dong Seon Kim; You Hui Lee; Jong Dae Park; Shin Il Kim

1997-01-01

356

Synthesis and Properties of Alkyl Glycoside and Stachyose Fatty Acid Polyesters  

Microsoft Academic Search

A solvent-free interesterification procedure was used to synthesize alkyl giycoside fatty acid polyesters: methyl glucoside\\u000a polyesters, methyl galactoside polyesters, octyl glucoside polyesters, and tetrasaccharide fatty acid polyester, stachyose\\u000a polyester. To obtain high yields, the hydroxyl groups on alkyl glycosides and stachyose were first protected by acetylation,\\u000a and thereafter interesterified with fatty acid methyl esters (FAME) of long chain fatty acids

Casimir C. Akoh; Barry G. Swanson

1989-01-01

357

Calcinogenic factor in Solanum malacoxylon: evidence that it is 1,25-dihydroxyvitamin D3-glycoside.  

PubMed

After glycosidic cleavage of the water-soluble vitamin D-like principle of the calcinogenic plant Solanum malacoxylon, the active lipophilic portion was purified by column chromatography and analyzed by combined gas chromatography and mass spectrometry. It was identified as 1,25-dihydroxyvitamin D3, the active form of vitamin D. Thus this active metabolite of vitamin D exists in the plant world, and its presence probably accounts for pathologic calcification in grazing animals ingesting Solanum malacoxylon. PMID:982048

Wasserman, R H; Henion, J D; Haussler, M R; McCain, T A

1976-11-19

358

Bioavailability of genistein, daidzein, and their glycosides in intestinal epithelial Caco-2 cells  

Microsoft Academic Search

In this study information was obtained on bioavailability of genistein, daidzein and their glycosides in human intestinal epithelial Caco-2 cells grown on semi-permeable filters. The integrity of Caco-2 monolayers was confirmed by transepithelial electrical resistance measurements and by determination of the permeability of the radioactive marker polyethylene glycol (PEG4000). After 6 h approximately 30–40% of genistein and daidzein added at

Aukje Steensma; Hub P. J. M Noteborn; Robert C. M. van der Jagt; Theo H. G Polman; Marcel J. B Mengelers; Harry A Kuiper

1999-01-01

359

Multifunctional, Biocompatible Supramolecular Hydrogelators Consist Only of Nucleobase, Amino Acid, and Glycoside  

PubMed Central

The integration of nucleobase, amino acid, and glycoside into a single molecule results in a novel class of supramolecular hydrogelators, which not only exhibit biocompatibility and biostability, but also facilitate the entry of nucleic acids into cytosol and nuclei of cells. This work illustrates a simple way to generate an unprecedented molecular architecture from the basic biological building blocks for the development of sophisticated soft nanomaterials, including supramolecular hydrogels.

Li, Xinming; Kuang, Yi; Shi, Junfeng; Gao, Yuan; Lin, Hsin-Chieh; Xu, Bing

2011-01-01

360

Characterisation of free and glycosidically bound odourant compounds of Aragonez clonal musts by GCO  

Microsoft Academic Search

To evaluate the potential aroma of Aragonez clonal red musts, several free and glycosidically bound odourant compounds were extracted. Then, the gas chromatography-olfactometry (GC-O) posterior intensity method was used to evaluate their odour intensity and the compounds were identified by gas chromatography–mass spectrometry (GC–MS). A group of eight sniffers evaluated free and bound fractions of Aragonez musts and perceived forty-three

Goreti Botelho; Arlete Mendes-Faia; Maria Cristina Clímaco

2010-01-01

361

Structure-activity relationships of novel neuritogenic steroid glycosides from the Okinawan starfish Linckia laevigata.  

PubMed

Six new steroid glycosides, linckosides F-K, and a related metabolite were isolated from the Okinawan blue starfish Linckia laevigata as mimics or enhancers of nerve growth factor (NGF). Their structures and stereochemistry were elucidated by spectroscopic methods and chemical derivatization. Structure-activity relationships suggest that both a carbon branch modified by a pentose at the side chain and 2'-O-methylxylopyranose at C-3 of the aglycon are important for neuritogenic activity. PMID:16524736

Han, Chunguang; Qi, Jianhua; Ojika, Makoto

2006-03-09

362

Synthesis of alkyl glycoside fatty acid esters in non-aqueous media by Candida sp. lipase  

Microsoft Academic Search

Alkyl glycoside fatty acid esters were successfully synthesized by lipase-catalyzed transesterification of methyl glucoside,\\u000a methyl glucoside, methyl galactoside and octyl glucoside with methyl oleate. The experiments were carried out in organic media\\u000a with lipase enzymes fromCandida sp. as biocatalysts. Time course and the effects of temperature, solvent type, substrate concentration, added water and of\\u000a immobilizedvs. nonimmobilized enzyme were studied. The

Lydia N. Mutua; Casimir C. Akoh

1993-01-01

363

The first ?-1,3-glucosidase from bacterial origin belonging to glycoside hydrolase family 31  

Microsoft Academic Search

Genome analysis of Lactobacillus johnsonii NCC533 has been recently completed. One of its annotated genes, lj0569, encodes the protein having the conserved domain of glycoside hydrolase family 31. Its homolog gene (ljag31) in L. johnsonii NBRC13952 was cloned and expressed using an Escherichia coli expression system, resulting in poor production of recombinant LJAG31 protein due to inclusion body formation. Production

Min-Sun Kang; Masayuki Okuyama; Haruhide Mori; Atsuo Kimura

2009-01-01

364

Detailed Kinetic Analysis of a Family 52 Glycoside Hydrolase:  A ?-Xylosidase from Geobacillus stearothermophilus †  

Microsoft Academic Search

Geobacillus stearothermophilusT-6 encodes for a ‚-xylosidase (XynB2) from family 52 of glycoside hydrolases that was previously shown to hydrolyze its substrate with net retention of the anomeric configuration. XynB2 significantly prefers substrates with xylose as the glycone moiety and exhibits a typical bell-shaped pH dependence curve. Binding properties of xylobiose and xylotriose to the active site were measured using isothermal

Tsafrir Bravman; Gennady Zolotnitsky; Valery Belakhov; Gil Shoham; Bernard Henrissat; Timor Baasov; Yuval Shoham

2003-01-01

365

Subcellular distribution of polysaccharide depolymerase and glycoside hydrolase enzymes in rumen ciliate protozoa  

Microsoft Academic Search

The distribution of polysaccharide depolymerase and glycoside (acid) hydrolase activity in nine genera of rumen entodiniomorphid and holotrich ciliate protozoa was examined by differential centrifugation. Sedimentable activity was detected in all of the protozoa examined and occurred principally in fractions that were prepared by centrifugation at 1000g for 10 min, 10,000g for 10 min, and 20,000g for 20 min (fractions

Alan G. Williams; Alec B. Ellis; Geoffrey S. Coleman

1986-01-01

366

Differential Recognition and Hydrolysis of Host Carbohydrate Antigens by Streptococcus pneumoniae Family 98 Glycoside Hydrolases  

Microsoft Academic Search

The presence of a fucose utilization operon in the Streptococcus pneumoniae genome and its established importance in virulence indicates a reliance of this bacterium on the harvesting of host fucose-containing glycans. The identities of these glycans, however, and how they are harvested is presently unknown. The biochemical and high resolution x-ray crystallographic analysis of two family 98 glycoside hydrolases (GH98s)

M. A. Higgins; G. E. Whitworth; N. El Warry; M. Randriantsoa; E. Samain; R. D. Burke; D. J. Vocadlo; A. B. Boraston

2009-01-01

367

Crystal Structure of Aspergillus niger Isopullulanase, a Member of Glycoside Hydrolase Family 49  

Microsoft Academic Search

An isopullulanase (IPU) from Aspergillus niger ATCC9642 hydrolyzes ?-1,4-glucosidic linkages of pullulan to produce isopanose. Although IPU does not hydrolyze dextran, it is classified into glycoside hydrolase family 49 (GH49), major members of which are dextran-hydrolyzing enzymes. IPU is highly glycosylated, making it difficult to obtain its crystal. We used endoglycosidase Hf to cleave the N-linked oligosaccharides of IPU, and

Masahiro Mizuno; Atsushi Koide; Akihiro Yamamura; Hiromi Akeboshi; Hiromi Yoshida; Shigehiro Kamitori; Yoshiyuki Sakano; Atsushi Nishikawa; Takashi Tonozuka

2008-01-01

368

Positive selection of three chitinase genes of the family 18 of glycoside hydrolases in mammals  

Microsoft Academic Search

The digestive enzyme chitinase degrades chitin, and is found in a wide range of organisms, from prokaryotes to eukaryotes.\\u000a Although mammals cannot synthesize or assimilate chitin, several proteins of the glycoside hydrolase (GH) chitinase family\\u000a GH18, including some with enzymatic activity, have recently been identified from mammalian genomes. Consequently, there is\\u000a growing interest in molecular evolution of this family of

Beibei He; Li Wang; Jinhong Wang; Gang Li; Shuyi Zhang

2009-01-01

369

Reversible variable length codes  

Microsoft Academic Search

Proposes some reversible variable length codes (RVLCs) which can be decoded instantaneously both in the forward and backward directions and have high transmission efficiency. These codes can be used, for example, in the backward reconstruction of video signals from the data last received when some signal is lost midway in the transmission. Schemes for a symmetrical RVLC requiring only a

Y. Takishima; M. Wada; H. Murakami

1995-01-01

370

Time reversal communication system  

SciTech Connect

A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.

Candy, James V. (Danville, CA); Meyer, Alan W. (Danville, CA)

2008-12-02

371

Reversible Ising dynamics  

SciTech Connect

The author discusses a reversible deterministic dynamics for Ising spins. The algorithm is a variation of microcanonical Monte Carlo techniques and is easily implemented with simple bit manipulation. This provides fast programs to study non-equilibrium phenomena such as heat flow.

Creutz, M.

1985-01-01

372

Reverse age discrimination  

Microsoft Academic Search

Purpose – The purpose of this paper is to draw attention to the fact that there is reverse age discrimination in the field of librarianship. Design\\/methodology\\/approach – Literature review and commentary on this topic that is now being addressed by our younger colleagues. Findings – Younger librarians often referred to as “baby librarians” are frustrated by their colleagues in the

Elisa F. Topper

2009-01-01

373

REVERSE WATERHAMMER - CASE STUDIES  

Microsoft Academic Search

Several cases and incidents caused by reverse waterhammer in hydraulic systems are analyzed. The paper describes the fundamentals of mathematical models for analysis of hydraulic transients in Kaplan turbines based upon the theory of the rigid waterhammer. The case of the air introduction into the intake structure behind the inlet wheel gate is described by a system of differential equations.

A. GAJI; B. IVLJANIN

374

Efficient synthesis of glycyrrhetinic acid glycoside/glucuronide derivatives using silver zeolite as promoter.  

PubMed

3-O-Glycopyranosides of glycyrrhetinic acid have been synthesized in good to high yields and excellent stereoselectivity using glycosyl bromide donors and silver zeolite as promoter. In addition to the preparation of glycosides containing beta-linked glucosyl, 2-deoxy-2-trichloroacetamido-glucosyl, galactosyl, cellobiosyl and lactosyl residues, also the deactivated acetylated methyl glucopyranosyluronate bromide donor could be coupled to triterpene aglycon ester derivatives in good yields. The ester protecting group located at C-30 of the oleanolic acid scaffold exerted an influence on the overall yield, with the methylester-protected glycosyl acceptor giving better yields compared to the allyl, benzyl as well as diphenylmethyl ester aglycon. The acetyl-protected glucuronides were differently deblocked in high yields via Zemplén deacetylation or via hydrogenolysis followed by Zemplén deacetylation, and alkaline hydrolysis, respectively, to allow for a selective liberation of the ester groups from either the glucuronide or the glycyrrhetinic acid unit, respectively. The target glycosides/glucuronides serve as probes for pharmaceutical studies aimed at defining structure-activity relationships of glycoside/glucuronide triterpenes. PMID:19428000

del Ruiz Ruiz, Maria Carmen; Amer, Hassan; Stanetty, Christian; Beseda, Igor; Czollner, Laszlo; Shah, Priti; Jordis, Ulrich; Kueenburg, Bernhard; Classen-Houben, Dirk; Hofinger, Andreas; Kosma, Paul

2009-04-20

375

Mechanoanions produced by mechanical fracture of bacterial cellulose: ionic nature of glycosidic linkage and electrostatic charging.  

PubMed

Mechanoanions were produced by heterogeneous scission of the glycosidic linkages of the main chain of bacterial cellulose (BC); scission was induced by mechanical fracture of the BC in a vacuum in the dark at 77 K. The mechanoanions were detected using electron-spin-trapping methods with tetracyanoethylene. The yield of mechanoanions was positively correlated with the absolute value of the change in the Mulliken atomic charge, which was used as a descriptor of the ionic nature of the glycosidic linkage. Homogeneous scission of the glycosidic linkages induced by mechanical fracture generated mechanoradicals, the electron affinity of which was estimated on the basis of the energy of the lowest unoccupied molecular orbital for the model structure of the mechanoradical. It was concluded that the electrostatic charging of BC is caused by electron transfer from mechanoanions to mechanoradicals, which have high electron affinities. The electrostatic charge density of BC in a vacuum in the dark at 77 K was estimated to be 6.00 × 10(-1) C/g. PMID:22978760

Sakaguchi, Masato; Makino, Masakazu; Ohura, Takeshi; Iwata, Tadahisa

2012-09-27

376

[Isolation and determination of homoeriodictyol-7-O-beta-D-glycoside in Viscum coloratum].  

PubMed

The homoeriodictyol-7-O-beta-D-glycoside was isolated from Viscum coloratum and identified by mass spectrometry and nuclear magnetic resonance (NMR) (1H NMR and 13C NMR). A method for determination of homoeriodictyol-7-O-beta-D-glycoside in Viscum coloratum was developed by using a Kromasil C18 column (200 mm x 4.6 mm i.d., 5 microm) with a mixture of acetonitrile and 0.5% glacial acetic acid solution (18:82, v/v) as mobile phase at a flow rate of 1.0 mL/min. The detection wavelength was set at 284 nm and temperature was set at 30 degrees C. The volume of injection was 10 miccro L. Good linear relationship (r = 0.9997) between the mass concentration and the peak area of homoeriodictyol-7-O-beta-D-glycoside was obtained in the range of 1.0-32.0 mg/L. The recoveries were found to be in the range of 96.0%-100.1%. The results of the experiments demonstrated that the established method is rapid and simple with good accuracy and reproducibility. The method is suitable for the quality control of Viscum coloratum from different sources. PMID:17165542

Zhao, Yunli; Ma, Mingyan; Gao, Xiaoxia; Liu, Tao; Yu, Zhiguo; Bi, Kaishun

2006-09-01

377

Rational design of an aryl-C-glycoside catalyst from a natural product O-glycosyltransferase.  

PubMed

Because the sugar moieties of natural products are primarily O-linked, the hydrolytic sensitivity of the glycosidic linkage limits their therapeutic application. One potential solution to this problem is to replace the labile O-glycosidic bond with an enzymatically and chemically stable C-glycosidic bond. In this study, computational analysis of the O-glycosyltransferase LanGT2 and the C-glycosyltransferase UrdGT2 was used to predict the changes necessary to switch the O-glycosylating enzyme to a C-glycosyltransferase. By screening rationally designed LanGT2 mutants a number of LanGT2 variants with C-glycosyltransferase activity were identified. One variant, having 10 amino acid substitutions, revealed the primary region that determines O- versus C-glycosylation. By modeling the active site of this mutant and probing the role of active site residues with alanine substitutions, this work also illuminates the mechanistic features of O- and C-glycosylation. PMID:21513888

Härle, Johannes; Günther, Stefan; Lauinger, Benjamin; Weber, Monika; Kammerer, Bernd; Zechel, David L; Luzhetskyy, Andriy; Bechthold, Andreas

2011-04-22

378

A new phenolic constituent and a cyanogenic glycoside from Balanophora involucrata (Balanophoraceae).  

PubMed

Balanophora involucrata HOOK.f. & THOMSON (Balanophoraceae) is a parasite plant often growing on the roots of leguminous plants. The whole herb has been used medicinally for the treatment of irregular menstruation, cough, hemoptysis, traumatic injury and bleeding, dizziness and gastralgia in Yunnan Province, China. The 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay on the 60% aq. acetone extract of the fresh whole plant of B. involucrata showed considerable radical-scavenging activity (SC?? 15.3 ?g/ml). Further purification on the extract led to the isolation of one new phenolic glycoside, sieboldin-3'-ketocarboxylic acid (1), and one new cyanogenic glycoside, proacacipetalin 6'-O-?-D-glucopyranoside (2), together with 26 known compounds including three 4"-O-galloyl and 2",3"-O-(S)-hexahydroxydiphenoyl (HHDP) derivatives of dihydrochalcone glucosides, seven hydrolyzable tannins, and alkane glycosides. The cyanogenic compound isolated from the Balanophoraceae family for the first time might be a signal molecule between B. involucrata and its hosts. The free-radical-scavenging activity of the isolated compounds was also examined by DPPH assay. PMID:23776023

She, Gai-Mei; Zhang, Ying-Jun; Yang, Chong-Ren

2013-06-01

379

Steroidal glycosides from Veronica chamaedrys L. Part I. The structures of chamaedrosides C, C1, C2, E, E1 and E2.  

PubMed

Two new spirostane glycosides, chamaedrosides C (1) and C1 (2), two new furostane glycosides, chamaedrosides E (4) and E1 (5), and two new furospirostane glycosides, chamaedrosides C2 (3) and E2 (6), have been isolated from Veronica chamaedrys L. plants. Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods, including 1D- and 2D-NMR experiments, as well as MS analysis. The given compounds have been found for the first time. PMID:22799076

Marchenko, Alexandra; Kintya, Pavel; Wyrzykiewicz, Bozena; Gorincioi, Elena

2012-05-01

380

49 CFR 230.89 - Reverse gear.  

Code of Federal Regulations, 2010 CFR

... 2009-10-01 2009-10-01 false Reverse gear. 230.89 Section 230.89 Transportation...Throttles and Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants...

2009-10-01

381

49 CFR 230.89 - Reverse gear.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 2010-10-01 false Reverse gear. 230.89 Section 230.89 Transportation...Throttles and Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants...

2010-10-01

382

Characterisation of proanthocyanidin aglycones and glycosides from rose hips by high-performance liquid chromatography-mass spectrometry, and their rapid quantification together with vitamin C.  

PubMed

Fifteen individual proanthocyanidin aglycones and 19 glycosides, together with a complex mixture of chromatographically non-separated tetra- to octameric proanthocyanidin glycosides were detected--the non-separated glycosides being novel natural products--and characterised from dog rose hips using high-performance liquid chromatography-electrospray ionisation mass spectrometry (HPLC-ESI-MS). Along with these phenolics, a 50% aqueous ethanol extract of rose hips was found to contain high levels of Vitamin C. A simple and rapid HPLC method assisted by diode array detection for the estimation of the total concentration of proanthocyanidin aglycones and glycosides, as well as Vitamin C, in rose hip extracts was developed. PMID:16001553

Salminen, Juha-Pekka; Karonen, Maarit; Lempa, Kyösti; Liimatainen, Jaana; Sinkkonen, Jari; Lukkarinen, Marjo; Pihlaja, Kalevi

2005-06-10

383

Quantitative determination of flavonoids and cycloartanol glycosides from aerial parts of Sutherlandia frutescens (L.) R. BR. by using LC-UV/ELSD methods and confirmation by using LC-MS method  

PubMed Central

This paper describes the first analytical method for the determination of four flavonoids (sutherlandins A–D) and four cycloartanol glycosides (sutherlandiosides A–D) from the aerial parts of Sutherlandia frutescens (L.) R. Br. A separation by HPLC was achieved by using a reversed phase (RP-18) column, PDA with ELS detection, and a water/acetonitrile gradient as the mobile phase. The wavelength used for quantification of four flavonoids with the diode array detector was 260 nm. Owing to their low UV absorption, the cycloartanol glycosides were detected by evaporative light scattering. The method was validated for linearity, repeatability, limits of detection (LOD) and limits of quantification (LOQ). The limits of detection and limits of quantification of eight compounds were found to be in the range from 0.1 to 7.5 µg/mL and 0.5 to 25 µg/mL, respectively. The analysis of products showed considerable variation of 1.099–5.224 mg/average weight for the major compound, sutherlandioside B. The eight compounds in plant sample and products of S. frutescens were further confirmed by LC–ESI-TOF. This method involved the use of the [M+H]+ and [M+Na]+ ions in the positive ion mode with extractive ion monitoring (EIM).

Avula, Bharathi; Wang, Yan-Hong; Smillie, Troy J.; Fu, Xiang; Li, Xing Cong; Mabusela, Wilfred; Syce, James; Johnson, Quinton; Folk, William; Khan, Ikhlas A.

2012-01-01

384

Reversible Aggregation of Albumin  

NASA Astrophysics Data System (ADS)

We explore the interactions in synovial fluid involving the polyelectrolyte sodium hyaluronate (NaHA) and plasma proteins in their native state (albumin and globulins). Rheological measurements on synovial fluid show it to be highly viscoelastic and also rheopectic (stress increases with time in steady shear). Equilibrium dialysis confirms the findings of Ogston and Dubin that there is no association between NaHA and albumin at physiological pH and salt. What we find instead is a reversible aggregation of albumin, with an association energy of order 3kT and commensurate association lifetime of order microseconds. Certain anti-inflammatory drugs are shown to prevent this reversible aggregation. The implications of these findings for synovial fluid and blood rheology are discussed.

Colby, Ralph H.; Oates, Katherine M. N.; Krause, Wendy E.; Jones, Ronald L.

2004-03-01

385

HIV-1 Reverse Transcription.  

PubMed

Reverse transcription is an obligatory step in retrovirus replication in the course of which the retroviral RNA/DNA-dependent DNA polymerase (RT) copies the single-stranded positive sense RNA genome to synthesize the double-stranded viral DNA. At the same time the RT-associated RNaseH activity degrades the genomic RNA template, which has just been copied. The viral nucleocapsid protein NCp7 is an obligatory partner of RT, chaperoning synthesis of the complete viral DNA flanked by the two long-terminal repeats (LTR), required for viral DNA integration into the host genome and its expression. Here we describe assays for in vitro and ex vivo monitoring of reverse transcription and the chaperoning role of the nucleocapsid protein (NC). PMID:24158814

Cimarelli, Andrea; Darlix, Jean-Luc

2014-01-01

386

A Reversibly Switching Surface  

NASA Astrophysics Data System (ADS)

We report the design of surfaces that exhibit dynamic changes in interfacial properties, such as wettability, in response to an electrical potential. The change in wetting behavior was caused by surface-confined, single-layered molecules undergoing conformational transitions between a hydrophilic and a moderately hydrophobic state. Reversible conformational transitions were confirmed at a molecular level with the use of sum-frequency generation spectroscopy and at a macroscopic level with the use of contact angle measurements. This type of surface design enables amplification of molecular-level conformational transitions to macroscopic changes in surface properties without altering the chemical identity of the surface. Such reversibly switching surfaces may open previously unknown opportunities in interfacial engineering.

Lahann, Joerg; Mitragotri, Samir; Tran, Thanh-Nga; Kaido, Hiroki; Sundaram, Jagannathan; Choi, Insung S.; Hoffer, Saskia; Somorjai, Gabor A.; Langer, Robert

2003-01-01

387

Reversed field pinch diagnostics  

SciTech Connect

The Reversed Field Pinch (RFP) is a toroidal, axisymmetric magnetic confinement configuration characterized by a magnetic field configuration in which the toroidal magnetic field is of similar strength to the poloidal field, and is reversed at the edge compared to the center. The RFP routinely operates at high beta, and is a strong candidate for a compact fusion device. Relevant attributes of the configuration will be presented, together with an overview of present and planned experiments and their diagnostics. RFP diagnostics are in many ways similar to those of other magnetic confinement devices (such as tokamaks); these lectures will point out pertinent differences, and will present some diagnostics which provide special insights into unique attributes of the RFP.

Weber, P.G.

1986-01-01

388

The reverse Stroop effect  

Microsoft Academic Search

In classic Stroop interference, manual or oral identification of sensory colors presented as incongruent color words is delayed\\u000a relative to simple color naming. In the experiment reported here, this effect was shown to all but disappear when the response\\u000a was simply to point to a matching patch of color. Conversely, strong reverse Stroop interference occurred with the pointing\\u000a task. That

Frank H. Durgin

2000-01-01

389

Engineering in Reverse!  

NSDL National Science Digital Library

Students learn about the process of reverse engineering and how this technique is used to improve upon technology. Students analyze push-toys and draw diagrams of the predicted mechanisms inside the toys. Then, they disassemble the toys and draw the actual inner mechanisms. By understanding how the push-toys function, students make suggestions for improvement, such as cost effectiveness, improved functionality, ecological friendliness and any additional functionality they determine is an improvement.

Integrated Teaching And Learning Program

390

Reversible Dysphasia and Statins  

PubMed Central

This paper presents a case of reversible dysphasia occurring in a patient prescribed atorvastatin in combination with indapamide. A milder dysphasia recurred with the prescription of rosuvastatin and was documented on clinical examination. This resolved following cessation of rosuvastatin. The case highlights both a need for a wider understanding of potential drug interactions through the CYP 450 system and for an increased awareness, questioning and reporting of drug side-effects.

2012-01-01

391

A Reversibly Switching Surface  

Microsoft Academic Search

We report the design of surfaces that exhibit dynamic changes in interfacial properties, such as wettability, in response to an electrical potential. The change in wetting behavior was caused by surface-confined, single-layered molecules undergoing conformational transitions between a hydrophilic and a moderately hydrophobic state. Reversible conformational transitions were confirmed at a molecular level with the use of sum-frequency generation spectroscopy

Joerg Lahann; Samir Mitragotri; Thanh-Nga Tran; Hiroki Kaido; Jagannathan Sundaram; Insung S. Choi; Saskia Hoffer; Gabor A. Somorjai; Robert Langer

2003-01-01

392

Geomagnetic Field During a Reversal.  

National Technical Information Service (NTIS)

By modifying the IGRF it is possible to learn what may happen to the geomagnetic field during a geomagnetic reversal. If the entire IGRF reverses then the declination and inclination only reverse when the field strength is zero. If only the dipole compone...

J. R. Heirtzler

2003-01-01

393

Reversible logic and quantum computers  

Microsoft Academic Search

This article is concerned with the construction of a quantum-mechanical Hamiltonian describing a computer. This Hamiltonian generates a dynamical evolution which mimics a sequence of elementary logical steps. This can be achieved if each logical step is locally reversible (global reversibility is insufficient). Computational errors due to noise can be corrected by means of redundancy. In particular, reversible error-correcting codes

Asher Peres

1985-01-01

394

Reversed-phase high-performance liquid chromatography of peptides of porcine pepsin prepared by the use of various forms of immobilized alpha-chymotrypsin.  

PubMed

Reversed-phase high-performance liquid chromatography (RP-HPLC) separation was used for the comparison of peptide maps of pepsin after its digestions by different forms of immobilized alpha-chymotrypsin. Porcine pepsin was hydrolysed with soluble alpha-chymotrypsin, with alpha-chymotrypsins glycosylated with lactose or galactose coupled to hydrazide derivative of cellulose, with alpha-chymotrypsin attached to poly(acrylamide-allyl glycoside) copolymer or to glycosylated hydroxyalkyl methacrylate copolymer Separon or to agarose gel Sepharose 4B. Efficiency of enzymatic protein cleavage with regard to peptide mapping of porcine pepsin has been examined by the use of alpha-chymotrypsins immobilized by different methods. Best results were achieved after hydrolysis with alpha-chymotrypsin immobilized on poly(acrylamide-allyl glycoside) copolymers. Alpha-chymotrypsin immobilized by this way has further three times higher relative specific activity in comparison with the soluble one. Modified alpha-chymotrypsin was not suitable for efficient pepsin cleavage. PMID:11302446

Vanková, H; Kucerová, Z; Turková, J

2001-03-25

395

Electron impact ion fragmentation pathways of peracetylated C-glycoside ketones derived from cyclic 1,3-diketones.  

PubMed

Monosaccharide C-glycoside ketones have been synthesized by aqueous-based Knoevenagel condensation of isotopically labeled and unlabeled aldoses with cyclic diketones, 5,5-dimethyl-1,3-cyclohexanedione (dimedone) and 1,3-cyclohexanedione (1,3-CHD). The reaction products and their corresponding acetylated analogs produce characteristic molecular adduct ions by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). Analysis of the peracetylated C-glycosides by electron ionization (EI) gas chromatography/mass spectrometry (GC/MS) revealed diagnostic fragment ions that have been used to deduce the EI fragmentation pathways and the structure of each C-glycoside ketone. Characteristic gluco- and ribo-specific ions were observed at m/z 350 and 278, respectively. Ions common to both carbohydrate fragmentation pathways were observed at m/z 193 and 169 for the dimedone-C-glycosides, and m/z 165 and 141 for the 1,3-CHD-C-glycosides. Ions with m/z 169 and 141 retain the anomeric carbon (carbon-1) of the original sugar, while m/z 193 and 165 are shown to retain carbons-1, 2, and 3. PMID:19291692

Adeuya, Anthony; Price, Neil P J

2009-04-01

396

Molluscicidal activity of cardiac glycosides from Nerium indicum against Pomacea canaliculata and its implications for the mechanisms of toxicity.  

PubMed

Cardiac glycosides from fresh leaves of Nerium indicum were evaluated for its molluscicidal activity against Pomacea canaliculata (golden apple snail: GAS) under laboratory conditions. The results showed that LC(50) value of cardiac glycosides against GAS was time dependent and the LC(50) value at 96 h was as low as 3.71 mg/L, which was comparable with that of metaldehyde at 72 h (3.88 mg/L). These results indicate that cardiac glycosides could be an effective molluscicide against GAS. The toxicological mechanism of cardiac glucosides on GAS was also evaluated through changes of selected biochemical parameters, including cholinesterase (ChE) and esterase (EST) activities, glycogen and protein contents in hepatopancreas tissues of GAS. Exposure to sublethal concentrations of cardiac glycosides, GAS showed lower activities of EST isozyme in the later stages of the exposure period as well as drastically decreased glycogen content, although total protein content was not affected at the end of 24 and 48 h followed by a significant depletion at the end of 72 and 96 h. The initial increase followed by a decline of ChE activity was also observed during the experiment. These results suggest that cardiac glycosides seriously impair normal physiological metabolism, resulting in fatal alterations in major biochemical constituents of hepatopancreas tissues of P. canaliculata. PMID:21843803

Dai, Lingpeng; Wang, Wanxian; Dong, Xinjiao; Hu, Renyong; Nan, Xuyang

2011-06-01

397

Reverse micelle supercritical fluid chromatography  

SciTech Connect

Reverse micelles in supercritical fluids may be used to replace more polar mobile phases for normal-phase chromatography with silica columns. Both liquid and supercritical propane reverse micelle mobile phases have been investigated at ambient and elevated temperatures and shown to provide a large decrease in retention for polar compounds compared to pure propane. The decreased efficiency due to mass transport limitations for liquid reverse micelle phases can be alleviated by operating at higher temperatures. Use of a reverse micelle containing supercritical fluid solvent further increases efficiency over reverse micelle liquid mobile phases.

Gale, R.W.; Fulton, J.L.; Smith, R.D.

1987-08-01

398

True reversal of Mu integration  

PubMed Central

We describe a high-temperature (75°C) transition in the Mu integration complex that causes efficient and true reversal of the integration reaction. A second reversal pathway, first described as ‘foldback' reversal for the HIV integrase, was also observed upon disassembly/reassembly of the Mu complex at normal temperatures. Both true and foldback reversal severed only one or the other of the two integrated Mu ends, and each exhibited distinct metal ion specificities. Our results directly implicate an altered transposase configuration in the Mu strand transfer complex that inhibits reversal, thereby regulating the directionality of transposition.

Au, T K; Pathania, Shailja; Harshey, Rasika M

2004-01-01

399

The role of water in the design of glycosidic linkage flexibility  

NASA Astrophysics Data System (ADS)

In this paper we show how a variety of computational methods are used to understand the role that water plays in the solution conformational dynamics of carbohydrates. A comparison is made between maltose and a designed disaccharide (?-D-Glc-NAc-(1?4)-?-D-Glc-3-NH2) in which the cross glycosidic linkage hydrogen bonds have been significantly strengthened. However, despite the stronger intramolecular hydrogen bonds in the maltose derivative, the correlation times for glycosidic dihedral angle fluctuations are approximately the same for the two sugars. Upon investigation of the water in the first hydration shells for the two disaccharides, high water probability densities were found between the functional groups straddling the glycosidic linkage that bonds the two monosaccharides together. This probability density corresponds to single water molecules forming bridging hydrogen bonds between the functional groups on either side of the linkage for periods of 3.66 ps in the case of maltose and 8.36 ps in the case of the amine derivative. Ab initio studies of saccharide structure interaction with single water molecules reveal that these intermolecular (sugar-solvent) hydrogen bonds are of similar strength to the intramolecular (sugar-sugar) hydrogen bonds. This combination of molecular dynamics and ab initio computational methods demonstrates that increasing the internal hydrogen bond strength in oligosaccharides does not lead to significantly slower internal molecular motion of these sugars in solution. The intermolecular hydrogen bonds formed with water compete equally with the intramolecular hydrogen bonds in the sugar. This result has important implications when considering hydrophobic versus hydrophilic effects in glycoproteins.

Naidoo, Kevin J.; Yu-Jen Chen, Jeff

400

Isolation and structural determination of steroidal glycosides from the bulbs of easter lily (Lilium longiflorum Thunb.).  

PubMed

The bulbs of the Easter lily ( Lilium longiflorum Thunb.) are used as a food and medicine in several Asian cultures, and they are cultivated as an ornamental plant throughout the world. A new steroidal glycoalkaloid and two new furostanol saponins, along with two known steroidal glycosides, were isolated from the bulbs of L. longiflorum. The new steroidal glycoalkaloid was identified as (22R,25R)-spirosol-5-en-3beta-yl O-alpha-l-rhamnopyranosyl-(1-->2)-[6-O-acetyl-beta-d-glucopyranosyl-(1-->4)]-beta-d-glucopyranoside. The new furostanol saponins were identified as (25R)-26-O-(beta-d-glucopyranosyl)-furost-5-en-3beta,22alpha,26-triol 3-O-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranosyl-(1-->3)-beta-d-glucopyranoside and (25R)-26-O-(beta-d-glucopyranosyl)-furost-5-en-3beta,22alpha,26-triol 3-O-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-xylopyranosyl-(1-->3)-beta-d-glucopyranoside. The previously known steroidal glycosides, (22R,25R)-spirosol-5-en-3beta-yl O-alpha-l-rhamnopyranosyl-(1-->2)-beta-d-glucopyranosyl-(1-->4)-beta-d-glucopyranoside and (25R)-26-O-(beta-d-glucopyranosyl)-furost-5-en-3beta,22alpha,26-triol 3-O-alpha-l-rhamnopyranosyl-(1-->2)-beta-d-glucopyranosyl-(1-->4)-beta-d-glucopyranoside were identified in L. longiflorum for the first time. These new compounds from L. longiflorum and the isolation methodologies employed can be used for studies on the biological role of steroidal glycosides in plant development and plant-pathogen interactions, as well as for studies in food and human health, for which little is known. PMID:20681669

Munafo, John P; Ramanathan, Ahalya; Jimenez, Leslie S; Gianfagna, Thomas J

2010-08-11

401

Mechanical compressibility of the glycosylphosphatidylinositol (GPI) anchor backbone governed by independent glycosidic linkages.  

PubMed

About 1% of the human proteome is anchored to the outer leaflet of cell membranes via a class of glycolipids called GPI anchors. In spite of their ubiquity, experimental information about the conformational dynamics of these glycolipids is rather limited. Here, we use a variety of computer simulation techniques to elucidate the conformational flexibility of the Man-?(1?2)-Man-?(1?6)-Man-?(1?4)-GlcNAc-?-OMe tetrasaccharide backbone 2 that is an essential and invariant part of all GPI-anchors. In addition to the complete tetrasaccharide structure, all disaccharide and trisaccharide subunits of the GPI backbone have been studied as independent moieties. The extended free energy landscape as a function of the corresponding dihedral angles has been determined for each glycosidic linkage relevant for the conformational preferences of the tetrasaccharide backbone (Man-?(1?2)-Man, Man-?(1?6)Man and Man-?(1?4)-GlcNAc). We compared the free energy landscapes obtained for the same glycosidic linkage within different oligosaccharides. This comparison reveals that the conformational properties of a linkage are primarily determined by its two connecting carbohydrate moieties, just as in the corresponding disaccharide. Furthermore, we can show that the torsions of the different glycosidic linkages within the GPI tetrasaccharide can be considered as statistically independent degrees of freedom. Using this insight, we are able to map the atomistic description to an effective, reduced model and study the response of the tetrasaccharide 2 to external forces. Even though the backbone assumes essentially a single, extended conformation in the absence of mechanical stress, it can be easily bent by forces of physiological magnitude. PMID:23061547

Wehle, Marko; Vilotijevic, Ivan; Lipowsky, Reinhard; Seeberger, Peter H; Silva, Daniel Varon; Santer, Mark

2012-11-13

402

Cardiac glycosides correct aberrant splicing of IKBKAP-encoded mRNA in familial dysautonomia derived cells by suppressing expression of SRSF3.  

PubMed

The ability to modulate the production of the wild-type transcript in cells bearing the splice-altering familial dysautonomia (FD) causing mutation in the IKBKAP gene prompted a study of the impact of a panel of pharmaceuticals on the splicing of this transcript, which revealed the ability of the cardiac glycoside digoxin to increase the production of the wild-type, exon-20-containing, IKBKAP-encoded transcript and the full-length I?B-kinase-complex-associated protein in FD-derived cells. Characterization of the cis elements and trans factors involved in the digoxin-mediated effect on splicing reveals that this response is dependent on an SRSF3 binding site(s) located in the intron 5' of the alternatively spliced exon and that digoxin mediates its effect by suppressing the level of the SRSF3 protein. Characterization of the digoxin-mediated effect on the RNA splicing process was facilitated by the identification of several RNA splicing events in which digoxin treatment mediates the enhanced inclusion of exonic sequence. Moreover, we demonstrate the ability of digoxin to impact the splicing process in neuronal cells, a cell type profoundly impacted by FD. This study represents the first demonstration that digoxin possesses splice-altering capabilities that are capable of reversing the impact of the FD-causing mutation. These findings support the clinical evaluation of the impact of digoxin on the FD patient population. PMID:23711097

Liu, Bo; Anderson, Sylvia L; Qiu, Jinsong; Rubin, Berish Y

2013-06-18

403

A reducing-end-acting chitinase from Vibrio proteolyticus belonging to glycoside hydrolase family 19  

Microsoft Academic Search

A chitinase gene belonging to the glycoside hydrolase family 19 from Vibrio proteolyticus (chi19) was cloned. The recombinant enzyme (Chi19) showed weak activities against polymeric substrates and considerable activities\\u000a against fully N-acetylated chitooligosaccharides, (GlcNAc)\\u000a n\\u000a , whose degree of polymerization was greater than or equal to five. It hydrolyzed (GlcNAc)\\u000a n\\u000a at the second linkage position from the reducing ends

Yuji Honda; Hajime Taniguchi; Motomitsu Kitaoka

2008-01-01

404

Smilasides M and N, two new phenylpropanoid glycosides from Smilax riparia.  

PubMed

Two new phenylpropanoid glycosides, smilasides M and N, together with the known compound 2',6'-diacetyl-3,6-diferuloylsucrose, were isolated and characterized from the roots and rhizomes of Smilax riparia A. DC. The structures of the new compounds were elucidated as 2',6'-diacetyl-3-Z-feruloyl-6-feruloylsucrose (1) and 2',6'-diacetyl-3-feruloyl-6-Z-feruloylsucrose (2) on the basis of extensive analysis of HR-ESI-MS, UV, IR, and 1D and 2D NMR spectroscopic data. PMID:22296157

Sun, Ting-Ting; Zhang, Dian-Wen; Han, Yan; Dong, Fang-Yan; Wang, Wei

2012-01-01

405

Tomato steroidal alkaloid glycosides, esculeosides A and B, from ripe fruits  

Microsoft Academic Search

Major novel steroidal alkaloid glycosides, named esculeoside A (1) and esculeoside B (2), have been isolated from the pink color-type and the red color-type, respectively, of the ripe tomato fruits of Lycopersicon esculentum MILL. for the first time. The structures of 1 and 2 have been characterized as 3-O-?-lycotetraosyl (5S,22S,23S,25S)-23-acetoxy-3?,27-dihydroxyspirosolane 27-O-?-d-glucopyranoside and 3-O-?-lycotetraosyl (5S,22S,23R,25S)-22,26-epimino-16?,23-epoxy-3?,23,27-trihydroxycholestane 27-O-?-d-glucopyranoside, respectively.

Yukio Fujiwara; Ayumi Takaki; Yukie Uehara; Tsuyoshi Ikeda; Masafumi Okawa; Ken Yamauchi; Masateru Ono; Hitoshi Yoshimitsu; Toshihiro Nohara

2004-01-01

406

A new phenolic glycoside from Chamaecyparis obtusa var. breviramea f. crippsii.  

PubMed

A new phenolic glycoside, 3-methoxyphenol 1-O-?-L-rhamnopyranosyl-(1?6)- O-?-D-glucopyranoside (1), was isolated from the 90% acetone extract of the branches and leaves of Chamaecyparis obtusa var. breviramea f. crippsii along with another 10 known phenolics 2-11. Their structures were determined mainly by means of MS, 1D- and 2D-NMR data. Cytotoxicities of compounds 3 and 5-11 were tested on BGC-823, Hela and A549 cancer cell lines, the results showed that compound 8 was bioactive and its IC(50) values were 6.9, 29.7 and 52.9 ?M, respectively. PMID:23334571

Zhang, Yu-Mei; Xu, Jian; Xiao, Lin; Zeng, Guang-Zhi; Sun, Zhang-Hua; Tan, Ning-Hua

2013-01-18

407

Acylated flavonol glycosides from Epimedium elatum, a plant endemic to the Western Himalayas.  

PubMed

Herba Epimedii is a well-known Botanical preparation used over long time in traditional Chinese medicine. The extracts and chemical constituents from Epimedium species are aphrodisiac as well as to treat many ailments. Chemical investigation of lonely species growing in Kashmir Himalaya Epimedium elatum was undertaken to evaluate its chemical profile. Two unusual substituted acylated flavonol glycosides named Elatoside A (1) and Elatoside B (2) have been isolated from the ethanolic extract of E. elatum along with 23 previously known ones (3-25). All isolates were evaluated for antimicrobial and PPAR-? ligand binding activity, and some of them appeared to be modestly active. PMID:22366553

Tantry, Mudasir A; Dar, Javid A; Idris, Ahmed; Akbar, Seema; Shawl, Abdul S

2012-02-18

408

Polyflavanostilbene A, a new flavanol-fused stilbene glycoside from Polygonum cuspidatum.  

PubMed

Polyflavanostilbene A, a new flavanol-fused stilbene glycoside, was isolated from the rhizome of Polygonum cuspidatum. Its unusual structure, including its absolute stereochemistry, was determined by UV, IR, HRESIMS, and 1D and 2D NMR data and by the comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Polyflavanostilbene A has an unprecedented rearranged flavanol skeleton fused to stilbene via a hexahydrocyclopenta[c]furan moiety. Polyflavanostilbene A showed strong inhibitory activity against ?-glucosidase with an IC(50) value of 17.7 ?M. PMID:23320550

Li, Fushuang; Zhan, Zhilai; Liu, Fu; Yang, Yanan; Li, Li; Feng, Ziming; Jiang, Jianshuang; Zhang, Peicheng

2013-01-15

409

Three new phenolic glycosides from the Tibetan medicinal plant Aconitum tanguticum.  

PubMed

Three new phenolic glycosides, such as (Z)-sinapic acid-4-O-?-d-allopyranoside (1), 3,4-dihydroxyphenethoxy-8-O-?-d-[6-O-(4-O-?-d-glucopyranosyl)-feruloyl]-glucopyranoside (2), and 4-dihydroxyphenethoxy-8-O-?-d-[6-O-(4-O-?-d-glucopyranosyl)-feruloyl]-glucopyranoside (3) were isolated from the EtOH extract of whole plant of Aconitum tanguticum (Maxim.) Stapf. The structures of the new compounds were elucidated by spectroscopic methods, and the total (1)H NMR and (13)C NMR chemical shifts were assigned. PMID:23768043

Xu, Lu; Luo, Ming; Lin, Li-Me; Zhang, Xiao; Li, Chun; Wang, Zhi-Min; Luo, Yong-Ming

2013-06-14

410

A set of two diastereomers of cyanogenic glycosides from Passiflora quadrangularis.  

PubMed

A set of two diastereomers of phenylcyano glycosides, (7S)- and (7R)-phenylcyanomethyl 1'-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (1, 2), were isolated from the methanol extract of dried vines of P. quadrangularis. The absolute configurations of the benzylic methine centers were determined mainly by the comparison of 13C NMR spectra of these compounds, prunasin (3) and sambunigrin (4), of which the last two cyanoglycosides are known to have (R)- and (S)-configurations, respectively. PMID:21922906

Saeki, Daisuke; Yamada, Takeshi; Kajimoto, Tetsuya; Muraoka, Osamu; Tanaka, Reiko

2011-08-01

411

Flavonol glycosides, nigelflavonosides A-F from the whole plant of Nigella glandulifera (Ranunculaceae).  

PubMed

Six new flavonol glycosides, nigelflavonosides A-F (1-6), together with a known compound (7) were isolated from the whole plant of Nigella glandulifera Freyn et Sint (Ranunculaceae). Structure elucidation, especially the localization of the glycosyl or acetyl groups, and complete (1)H- and (13)C-NMR assignments of these compounds were carried out using one- and two-dimensional NMR measurements, including (1)H- and (13)C-NMR, (1)H-(1)H COSY, TOCSY, HMQC, HMBC and NOESY, in addition to HRESI-TOF-MS experiments. PMID:22327801

Zhang, Yi; Ge, Dandan; Chen, Qiu; He, Wei; Han, Lifeng; Wei, Hongyan; Jia, Xiaoguang; Wang, Tao

2012-02-12

412

Two new furostanol glycosides from the fibrous root of Ophiopogon japonicus (Thunb.) Ker-Gawl.  

PubMed

Two new furostanol glycosides, ophiopogonins H (1) and I (2), were isolated from the fibrous root of Ophiopogon japonicus. The structures of 1 and 2 were established as (25R)-26-[(O-?-D-glucopyranosyl-(1?2)-?-D-glucopyranosyl)]-22?-hydroxyfurost-5-ene-3-O-[?-L-rhamnopyranosyl-(1?2)]-?-D-glucopyranoside and (25R)-26-[(O-?-D-glucopyranosyl-(1?2)-?-D-glucopyranosyl)]-20?-hydroxyfurost-5,22-diene-3-O-[?-L-rhamnopyranosyl-(1?2)]-?-D-glucopyranoside on the basis of spectroscopic means including HR-ESI-MS, 1D and 2D NMR experiments. PMID:20839120

Duan, Chang-Ling; Ma, Xiao-Feng; Jiang, Yong; Liu, Jian-Xun; Tu, Peng-Fei

2010-09-01

413

Two new hemiterpene glycosides from the leaves of Ilex rotunda. Thunb.  

PubMed

Chromatographic separation of the 80% MeOH extract of the leaves of Ilex rotunda (IR) led to isolation of two new hemiterpene glycosides, tentatively named as rotundarpenoside A (1) and rotundarpenoside B (2), along with five known caffeoyl derivatives (3-7). The chemical structures of these compounds were elucidated using 1D/2D NMR, HR-MS, and the absolute configuration was confirmed by Mosher's method. In order to evaluate their anti-oxidative activities, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and xanthine oxidase superoxide scavenging activities (NBT) were determined. PMID:23139129

Kim, Manh Heun; Park, Kwan Hee; Oh, Myeong Hwan; Kim, Han Hyuk; Choe, Kang In; Park, Sang Hee; Lee, Min Won

2012-11-09

414

Ginsenoside Rg 5 , a genuine dammarane glycoside from Korean red ginseng  

Microsoft Academic Search

A genuine dammarane glycoside, named ginsenoside Rg5, has been isolated by repeated column chromatography and preparative HPLC from the MeOH extract of Korean red ginseng (Panax ginseng C.A. Meyer). The chemical structure of ginsenoside Rg5 was determined as 3-O-[?-D-glucopyranosyl (1?2)-?-D-glucopyranosyl] dammar-20(22),24-diene-3?,12?-diol by spectral and chemical\\u000a methods. The stereostructure of a double bond at C-20(22) of ginsenoside Rg5 was characterized as

Shin Il Kim; Jeong Hill Park; Jae-Ha Ryu; Jong Dae Park; You Hui Lee; Jae-Hyun Park; Tae-Hee Kim; Jong Moon Kim; Nam-In Baek

1996-01-01

415

Quantification of the flavonoid glycosides in Passiflora incarnata by capillary electrophoresis.  

PubMed

Capillary electrophoresis has been applied for the separation and quantification of the flavonoids in Passiflorae herba. Separations were performed using 25 mM sodium borate with 20 % methanol (pH 9.5). For the quantification quercetin 3-O-arabinoside was used as internal standard. The method was applied to the determination of the flavonoid glycosides in 10 different commercial samples of the drug and showed similar flavonoid patterns, but differences concerning the single and total amounts of flavonoids. The total flavonoid contents determined with the new method correlated satisfactorily with those achieved by the spectrophotometric assay according to the European Pharmacopoeia. PMID:12802728

Marchart, Elke; Krenn, Liselotte; Kopp, Brigitte

2003-05-01

416

Improvement of phenylethanoid glycosides production by a fungal elicitor in cell suspension culture of Cistanche deserticola.  

PubMed

When, on the 15th day of growth, an elicitor from Fusarium solani was added at 40 mg l(-1) to Cistanche deserticola cell suspension cultures, the contents of echinacoside, acteoside and total phenylethanoid glycosides (PeGs) in cultured cells all increased over the next 27 d by over 100% to 15 mg g(-1) dry wt, 9 mg g(-1) dry wt and 57 mg g(-1) dry wt, respectively. The final biomass (1.3 mg dry wt ml(-1)) was not affected. PMID:14514046

Lu, Cui-tao; Mei, Xing-guo

2003-09-01

417

Formation of phenylethanoid glycosides by Cistanche deserticola callus grown on solid media.  

PubMed

The optimal growth of Cistanche deserticola callus and formation of phenylethanoid glycosides (PeG) was at 25 degrees C with light irradiation intensity of 24 micromol m(-2) s(-1) on solidified B5 media supplemented with 0.5 mg 6-benzylaminopurine l(-1), 10 mg gibberellin l(-1), 800 mg casein hydrolysate l(-1) and 20 g sucrose l(-1). After 30 d culture, the biomass reached 15.5 g dry wt callus l(-1) medium and its PEG content was 10.7% (w/w). The PeG content was 42%-127% higher than those in explants. PMID:12882575

Ouyang, Jie; Wang, Xiao-dong; Zhao, Bing; Wang, Yu-chun

2003-02-01

418

Fast repair of thymine-hydroxyl radical adduct by phenylpropanoid glycosides  

NASA Astrophysics Data System (ADS)

The repair effect on thymine-hydroxyl adduct by phenylpropanoid glycosides (PPG): verbascoside, and pedicularioside A, isolated from Pedicularis, were studied using pulse radiolysis technique. From the analysis of transient absorption spectra, the rapid electron transfer from PPG to T-OH- was observed. Phenoxyl radical of PPG were generated via one-electron-transfer reaction. This result showed that two PPG exhibited repair activities on oxidizing T-OH-. The reaction rate constants of electron transfer from PPGs were 1.27 × 109 and 1.29 × 109 dm3.mol-1.s-1, respectively.

Li, Wenyan; Zou, Zhihua; Zheng, Rongliang; Wang, Changzeng; Jia, Zhongjian; Yao, Side; Lin, Nianyun

1997-04-01

419

Purification and Characterization of a Glycoside Hydrolase Family 43 ?-xylosidase from Geobacillus thermoleovorans IT08  

Microsoft Academic Search

The gene encoding a glycoside hydrolase family 43 ?-xylosidase (GbtXyl43A) from the thermophilic bacterium Geobacillus thermoleovorans strain IT-08 was synthesized and cloned with a C-terminal His-tag into a pET29b expression vector. The recombinant gene product\\u000a termed GbtXyl43A was expressed in Escherichia coli and purified to apparent homogeneity. Michaelis–Menten kinetic parameters were obtained for the artificial substrates p-nitrophenyl-?-d-xylopyranose (4NPX) and p-nitrophenyl-?-l-arabinofuranose

Kurt Wagschal; Chamroeun Heng; Charles C. Lee; George H. Robertson; William J. Orts; Dominic W. S. Wong

2009-01-01

420

Biochemical characterization of a glycoside hydrolase family 61 endoglucanase from Aspergillus kawachii  

Microsoft Academic Search

The glycoside hydrolase family 61 endoglucanase from Aspergillus kawachii (AkCel61) is a modular enzyme that consists of a catalytic domain and a carbohydrate-binding module belonging to family 1\\u000a (CBM1) that are connected by a Ser-Thr linker region longer than 100 amino acids. We expressed the recombinant AkCel61, wild-type\\u000a enzyme (rAkCel61), and a truncated enzyme consisting of the catalytic domain (rAkCel61?CBM)

Takuya Koseki; Yuichiro Mese; Shinya Fushinobu; Kazuo Masaki; Tsutomu Fujii; Kiyoshi Ito; Yoshihito Shiono; Tetsuya Murayama; Haruyuki Iefuji

2008-01-01

421

Reversible fragrance emitting unit  

US Patent & Trademark Office Database

A reversible fragrance emitting unit adapted to rest on a table or other flat surface in either an upright position in which the rate of fragrance emission is low, or in an upside down position in which the emission rate is high, the unit having the same attractive outward appearance in either state. The unit consists of a fenestrated open-ended shell having a decorative form whose inlet and outlet ends are attached to inlet and outlet boxes of like dimensions, both having bottom walls. The inlet box has an open top, whereas the outlet box is closed by a top wall to define an internal chamber which extends through the shell between the bottom wall of the inlet box and the top wall of the outlet box. The chamber contains a charge of fragrance-emitting pellets in an amount sufficient to almost fill the inlet box when the unit is placed in its upright position in which the inlet box rests on the table and the pellets are confined within the inlet box and therefore emit relatively little fragrance, the unit being effectively "off". When, however, the unit is reversed to occupy its upside down position in which the outlet box rests on the table, the pellets then occupy the shell and emit fragrance through the openings therein at a much greater rate and the unit is "on".

Spector; Donald (Union City, NJ)

1986-09-16

422

Reversing anticoagulant therapy.  

PubMed

For more than 50 years, heparin(s) and warfarin have been the most important anticoagulant agents, and clinicians are accustomed to their specific antidotes (protamine sulfate and vitamin K/plasma [or factor concentrates], respectively). Recently, there has been an explosion of novel anticoagulant development: ideally, these newer agents should have advantages over traditional anticoagulants, such as fewer side effects, a more predictable pharmacokinetic profile (and potentially no need for monitoring), minimal drug-drug interactions, and so forth. But, unlike the older agents, the newer anticoagulants do not have specific antidotes. There is increasing focus on the use of nonspecific procoagulants, such as non-activated and activated prothrombin complex concentrates (PCCs) and recombinant factor VIIa (rFVIIa), to manage major bleeding or need for emergency invasive procedures. This paper reviews several of the novel anticoagulants and presents the available evidence for their "reversal". Based on extrapolation from animal models, clinical anecdote, and an understanding of their mechanism of action, we recommend treating major bleeding complications of DTIs, as follows (in descending order of preference): activated PCCs; rFVIIa; and (non-activated) PCCs. For management of fondaparinux-associated bleeding, rFVIIa has some rationale (for which we provide an illustrative case). The increasing use of novel anticoagulants will require physicians to have an understanding of rational approaches to "reverse" their anticoagulant effects when true antidotes do not exist. PMID:22023256

Ghanny, Shari; Warkentin, Theodore E; Crowther, Mark A

2012-06-01

423

Addition of Electrophilic Radicals to 2-Benzyloxyglycals: Synthesis and Functionalization of Fluorinated ?-C-Glycosides and Derivatives.  

PubMed

A new method for the synthesis of fluorinated ?-C-glycosides is described. The reactions between highly electrophilic radicals (fluorinated or unfluorinated) and a 2-benzyloxyglucal or galactal provide 2-keto-D-arabino- or 2-keto-D-lyxo-hexopyranosides through an addition/fragmentation process. Sodium borohydride mediated or Meerwein-Ponndorf-Verley (MPV) reduction of these compounds provides ?-C-glycosides that feature appropriate anchoring groups for further synthetic elaboration. The presence of CF2 CO2 iPr or CF2 Br groups at the pseudo-anomeric position allows efficient reduction/olefination or Br/Li-exchange/nucleophilic-addition sequences. These transformations open the way for the synthesis of fluorinated C-glycosidic analogues of glycoconjugates. PMID:23955898

Colombel, Sophie; Van Hijfte, Nathalie; Poisson, Thomas; Leclerc, Eric; Pannecoucke, Xavier

2013-08-16

424

Polymerized liposomes containing C-glycosides of sialic acid: Potent inhibitors of influenza virus in vitro infectivity  

SciTech Connect

The surface lectin of the influenza virus, hemagglutinin, binds to terminal [alpha]-glycosides of N-acetylneuraminic acid (NeuAc) on cell-surface glycoproteins and glycolipids. Viral binding to cells expression terminal NeuAc residues can be inhibited by [alpha]-O-glycosides of NeuAc (O-sialosides). Recently, dramatic enhancements in the inhibition of viral adhesion to erythrocytes have been achieved using synthetic polyvalent sialosides. In this communication, the authors report that polymerized liposomes containing [alpha]-C-glycosides of sialic acid are potent inhibitors of influenza virus in vitro infectivity. Their results also indicate that the capacity to inhibit hemagglutination does not necessarily reflect the capacity to inhibit in vitro infectivity. 14 refs., 1 tab.

Spevak, W.; Bednarski, M.D.; Nagy, J.O.; Charych, D.H (Lawrence Berkeley Lab., CA (United States)); Schaefer, M.E.; Gilbert, J.H. (Glycomed, Inc., Alameda, CA (United States))

1993-02-10

425

The Ramberg-Bäcklund reaction for the synthesis of C-glycosides, C-linked-disaccharides and related compounds.  

PubMed

The discovery of the Ramberg-Bäcklund procedure for preparing exo-glycals from S-glycoside dioxides, developed independently in (Old) York and New York, is reviewed. The methodology is successful with glucose, galactose, mannose, xylose, fucose, ribose, altrose, 2-deoxy-arabino-hexose (2-deoxy-glucose) and daunosamine derivatives, and has been used to prepare di-, tri- and tetra-substituted exo-glycals. More recent developments, such as one-pot variants, and protecting group-free procedures, are also covered. Synthetic applications of the exo-glycals, for example, to prepare beta-glycosidase inhibitors, spirocyclic glucose derivatives, beta-C-glycosides, C-glycosyl porphyrin glycoconjugates and C-glycosyl amino acids, are also discussed. Finally, applications of the Ramberg-Bäcklund process for the synthesis of known and novel C-glycosides, and in natural product synthesis, are reviewed. PMID:16631146

Taylor, Richard J K; McAllister, Graeme D; Franck, Richard W

2006-05-02

426

A new group of exo-acting family 28 glycoside hydrolases of Aspergillus niger that are involved in pectin degradation  

PubMed Central

The fungus Aspergillus niger is an industrial producer of pectin-degrading enzymes. The recent solving of the genomic sequence of A. niger allowed an inventory of the entire genome of the fungus for potential carbohydrate-degrading enzymes. By applying bioinformatics tools, 12 new genes, putatively encoding family 28 glycoside hydrolases, were identified. Seven of the newly discovered genes form a new gene group, which we show to encode exoacting pectinolytic glycoside hydrolases. This group includes four exo-polygalacturonan hydrolases (PGAX, PGXA, PGXB and PGXC) and three putative exo-rhamnogalacturonan hydrolases (RGXA, RGXB and RGXC). Biochemical identification using polygalacturonic acid and xylogalacturonan as substrates demonstrated that indeed PGXB and PGXC act as exo-polygalacturonases, whereas PGXA acts as an exo-xylogalacturonan hydrolase. The expression levels of all 21 genes were assessed by microarray analysis. The results from the present study demonstrate that exo-acting glycoside hydrolases play a prominent role in pectin degradation.

Martens-Uzunova, Elena S.; Zandleven, Joris S.; Benen, Jaques A. E.; Awad, Hanem; Kools, Harrie J.; Beldman, Gerrit; Voragen, Alphons G. J.; Van Den Berg, Johan A.; Schaap, Peter J.

2006-01-01

427

Analysis of eleven iridoid glycosides by micellar electrokinetic capillary chromatography (MECC) and screening of plant samples by partial filling (MECC)–electrospray ionisation mass spectrometry  

Microsoft Academic Search

Of ammonium, lithium and sodium salts of dodecyl sulfate studied as surfactants in the separation of iridoid glycosides by micellar electrokinetic capillary chromatography (MECC), the last one gave the best results. Eleven neutral iridoid glycosides were separated by MECC with sodium dodecyl sulfate as surfactant, and the water–micelle partition coefficients of the compounds were calculated. The separation system was coupled

Johanna Suomi; Susanne K Wiedmer; Matti Jussila; Marja-Liisa Riekkola

2002-01-01

428

The Structure and Function of an Arabinan-specific [alpha]-1,2Arabinofuranosidase Identified from Screening the Activities of Bacterial GH43 Glycoside Hydrolases  

Microsoft Academic Search

Reflecting the diverse chemistry of plant cell walls, microorganisms that degrade these composite structures synthesize an array of glycoside hydrolases. These enzymes are organized into sequence-, mechanism-, and structure-based families. Genomic data have shown that several organisms that degrade the plant cell wall contain a large number of genes encoding family 43 (GH43) glycoside hydrolases. Here we report the biochemical

Alan Cartmell; Lauren S. McKee; Maria J. Pena; Johan Larsbrink; Harry Brumer; Satoshi Kaneko; Hitomi Ichinose; Richard J. Lewis; Anders Vikso-Nielsen; Harry Gilbert; Jon Marles-Wright

2012-01-01

429

Flavonoid Glycosides and Naphthodianthrones in the Sawfly Tenthredo zonula and its Host-Plants, Hypericum perforatum and H. hirsutum  

PubMed Central

Larvae of the sawfly Tenthredo zonula are specialized on Hypericum. Whether the sawfly is able to sequester plant metabolites was unknown. Aerial materials of Hypericum perforatum and H. hirsutum, as well as dissected larvae and prepupae of T. zonula, were analyzed by HPLC to determine the presence and content of flavonoid glycosides (rutin, hyperoside, isoquercitrin, and quercitrin) and naphthodianthrones (pseudohypericin and hypericin). All flavonoid glycosides were detected in both Hypericum species, with hyperoside as major compound in H. perforatum (ca. 1.7 ?mol/g fresh weight, FW) and isoquercitrin in H. hirsutum (0.7 ?mol/g FW). Naphthodianthrones were present at low concentrations (0.02 ?mol/g FW) in the former, and almost undetected in the latter species. In the body parts (i.e., hemolymph, digestive tract, salivary glands, or miscellaneous organs) of T. zonula, the surveyed compounds were detected more frequently in prepupae than in larvae. The compounds were not present in every sample, and flavonoid glycosides especially occurred in highly variable amounts, with maximal concentrations of 41 ?g rutin/prepupa in salivary glands, 8 ?g hyperoside/prepupa in hemolymph (= 0.36 ?mol/g FW), 32 ?g isoquercitrin/prepupa in salivary glands, and 63 ?g quercitrin/larva in miscellaneous organs (mainly composed of the integument). We conclude that flavonoid glycosides are sequestered since they were detected in organs other than the digestive tract of larvae, and because prepupae are a non-feeding stage. The naphthodianthrone pseudohypericin, but not hypericin, occurred generally in the digestive tract (up to 0.25 ?g/larva). Both naphthodianthrones and related unidentified compounds, but not flavonoid glycosides, were found in the larval excrement. The highly variable distributions of flavonoid glycosides and naphthodianthrones in T. zonula larvae and prepupae make it difficult to determine the ecological significance of these metabolites.

2012-01-01

430

[Reversible cerebral vasoconstriction syndrome].  

PubMed

Reversible cerebral vasoconstriction syndrome (RCVS) is more frequent than previously thought and is probably underdiagnosed. The mean age of onset is 42 years, and it affects slightly more women than men. RCVS is attributed to a transient, reversible dysregulation of cerebral vascular tone, which leads to multifocal arterial constriction and dilation. More than half the cases (60%) are secondary to exposure to vasoactive substances (e.g., cannabis, antidepressants, and nasal decongestants) or occur in the postpartum period. RCVS has a characteristic clinical and radiological course, developing in a single phase after a sudden onset, and there is generally no new event after 1 month. The main pattern of presentation begins with recurrent thunderclap headaches, often triggered by sexual activity or various Valsalva's maneuvers, over a period of 1 to 3 weeks. Seizures and focal neurological deficits are less frequent and generally start after the headaches. Cortical subarachnoid hemorrhage (22%), intracerebral hemorrhage (6%), seizures (3%), and reversible posterior leukoencephalopathy (9%) are early complications, occurring mainly within the first week. Ischemic events, including TIAs (16%) and cerebral infarction (4%), occur significantly later than hemorrhagic strokes, mainly during the second week. Diagnosis requires the demonstration of the characteristic "string and beads" on cerebral angiography and can be difficult, for 21% of patients have a normal initial magnetic resonance angiography (MRA) and 9% both a normal MRA and a normal transcranial Doppler. In these cases, the initial investigations must be repeated after a few days. The final diagnosis is made when a follow-up MRA shows resolution or at least marked improvement of the arterial abnormalities within 12 weeks. RCVS is sometimes associated with other large artery lesions of the head and neck, including dissections and unruptured aneurysms, especially during the postpartum period. Nimodipine is the treatment most often recommended. In our experience, it is not especially effective in severe RCVS. Relapses are possible but rare and have not yet been reported in prospective series. Although the exact pathophysiology remains speculative, strong recommendations against vasoactive substances appear prudent. PMID:19945250

Ducros, Anne

2009-11-27

431

Reverse photoacoustic standoff spectroscopy  

DOEpatents

A system and method are disclosed for generating a reversed photoacoustic spectrum at a greater distance. A source may emit a beam to a target and a detector measures signals generated as a result of the beam being emitted on the target. By emitting a chopped/pulsed light beam to the target, it may be possible to determine the target's optical absorbance by monitoring the intensity of light collected at the detector at different wavelengths. As the wavelength of light is changed, the target may absorb or reject each optical frequency. Rejection may increase the intensity at the sensing element and absorption may decrease the intensity. Accordingly, an identifying spectrum of the target may be made with the intensity variation of the detector as a function of illuminating wavelength.

Van Neste, Charles W. (Kingston, TN); Senesac, Lawrence R. (Knoxville, TN); Thundat, Thomas G. (Knoxville, TN)

2011-04-12

432

Contrast reversal confocal microscopy  

NASA Astrophysics Data System (ADS)

We propose a novel method to improve the lateral resolution of a general confocal laser scanning microscopy (CLSM) by 10-35%, which can be readily realized by manipulating the shape of the excitation focal spot to a doughnut one. As the contrast of image is reversed synchronously, the raw data is further handled by the deconvolution algorithm to convert the doughnut point spread function (PSF) to a peak-centered distribution, so that a more intuitive vision will be given. Depending on the strategies like saturation excitation or doughnut size shrinkage, the resolution can be further optimized. This setup is valid for diverse systems and may find use in a variety of applications.

Hao, Xiang; Kuang, Cuifang; Gu, Zhaotai; Li, Shuai; Li, Yanghui; Liu, Xu

2013-07-01

433

Reversible fluctuation rectifier.  

PubMed

The analysis of a Feynman's ratchet system [J. M. R. Parrondo and P. Espańol, Am. J. Phys. 64, 1125 (1996)] and of its electrical counterpart, a diode engine [I. M. Sokolov, Europhys. Lett. 44, 278 (1998)] has shown that "fluctuation rectifiers" consisting of a nonlinear element (ratchet, diode) and a linear element (vane, resistor) kept at different temperatures always show efficiency smaller than the Carnot value, thus indicating the irreversible mode of operation. We show that this irreversibility is not intrinsic for a system in simultaneous contact with two heat baths at different temperatures and that a fluctuation rectifier can work reversibly. This is illustrated by a model with two diodes switched in opposite directions, where the Carnot efficiency is achieved when backward resistivity of the diodes tends to infinity. PMID:11970361

Sokolov, I M

1999-10-01

434

Reversible fluctuation rectifier  

NASA Astrophysics Data System (ADS)

The analysis of a Feynman's ratchet system [J. M. R. Parrondo and P. Espańol, Am. J. Phys. 64, 1125 (1996)] and of its electrical counterpart, a diode engine [I. M. Sokolov, Europhys. Lett. 44, 278 (1998)] has shown that ``fluctuation rectifiers'' consisting of a nonlinear element (ratchet, diode) and a linear element (vane, resistor) kept at different temperatures always show efficiency smaller than the Carnot value, thus indicating the irreversible mode of operation. We show that this irreversibility is not intrinsic for a system in simultaneous contact with two heat baths at different temperatures and that a fluctuation rectifier can work reversibly. This is illustrated by a model with two diodes switched in opposite directions, where the Carnot efficiency is achieved when backward resistivity of the diodes tends to infinity.

Sokolov, I. M.

1999-10-01

435

Polarization reversal in ? crystals  

NASA Astrophysics Data System (ADS)

Characteristics of spontaneous polarization reversal have been studied in detail for the first time in 0022-3727/30/2/016/img8 crystals subjected to a pulsed electric field in the range 15 - 70 kV 0022-3727/30/2/016/img9. The switching process has been observed by recording a transient switching current and subsequent piezoelectric probe mapping and optical and secondary electron microscopy methods. The measured value of spontaneous polarization is 0022-3727/30/2/016/img10. The ionic potassium DC current was observed to have a strong effect on the polarization switching. The developed experimental set-up has made it possible to fabricate a periodic domain structure and to generate an optical second harmonic power.

Rosenman, G.; Skliar, A.; Oron, M.; Katz, M.

1997-01-01

436

Reversible leukoencephalopathy syndrome.  

PubMed

Reversible encephalopathy syndrome is a multietiological condition, the pathophysiology of which lies in the breach of the blood-brain barrier due to increased local cerebral perfusion pressure. Patients present clinically in nonspecific ways; acute computed tomography is often unrevealing, and as such, there should be a low threshold for early magnetic resonance imaging even in the acute setting because misdiagnosis may lead to mismanagement. Although initially described to present with changes depicted on imaging in the "posterior aspects" of the brain, more recent literature has focused attention on the fact that signal changes may occur anywhere in the brain. We present a case demonstrating such prolific changes throughout the brain stressing on the need for early appropriate use of radiodiagnostics. PMID:20223406

Mankad, Kshitij; Hoey, Edward; Yap, Ki Sing

2010-03-01

437

46,XX sex reversal.  

PubMed

In humans, sexual differentiation is directed by SRY, a master regulatory gene located at the Y chromosome. This gene initiates the male pathway or represses the female pathway by regulating the transcription of downstream genes; however, the precise mechanisms by which SRY acts are largely unknown. Moreover, several genes have recently been implicated in the development of the bipotential gonad even before SRY is expressed. In some individuals, the normal process of sexual differentiation is altered and a sex reversal disorder is observed. These subjects present the chromosomes of one sex but the physical attributes of the other. Over the past years, considerable progress has been achieved in the molecular characterization of these disorders by using a combination of strategies including cell biology, animal models, and by studying patients with these pathologic entities. PMID:11750731

Zenteno-Ruiz, J C; Kofman-Alfaro, S; Méndez, J P

438

Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community  

SciTech Connect

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Smallsubunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ,10percent were putative cellulasesmostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50uC and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

Reddy, Amitha; Allgaier, Martin; Park, Joshua I.; Ivanoval, Natalia; Dhaeseleer, Patrik; Lowry, Steve; Sapra, Rajat; Hazen, Terry C.; Simmons, Blake A.; VanderGheynst, Jean S.; Hugenholtz, Philip

2011-05-11

439

Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community  

PubMed Central

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ?10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50°C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

Allgaier, Martin; Reddy, Amitha; Park, Joshua I.; Ivanova, Natalia; D'haeseleer, Patrik; Lowry, Steve; Sapra, Rajat; Hazen, Terry C.; Simmons, Blake A.; VanderGheynst, Jean S.; Hugenholtz, Philip

2010-01-01

440

Antiproliferative and hypoglycemic cucurbitane-type glycosides from the fruits of Momordica charantia.  

PubMed

This paper reports that bioassay-guided fractionations of EtOH extract of Momordica charantia fruits led to the isolation of 15 cucurbitane-type triterpene glycosides including 4 new compounds, kuguaosides A-D (1-4), along with 11 known ones, charantoside A (5), momordicosides I (6), F1 (7), F2 (8), K (9), L (10), and U (11), goyaglycosides-b (12) and -d (13), 7?,25-dihydroxycucurbita-5,23(E)-dien-19-al 3-O-?-d-allopyranoside (14), and 25-hydroxy-5?,19-epoxycucurbita-6,23-dien-19-on-3?-ol 3-O-?-d-glucopyranoside (15). Their structures were elucidated on the basis of spectroscopic analyses and chemical methods. This study also established the HPLC-ELSD fingerprinting profile of an antiproliferative fraction of which 11 main peaks were identified. Biological evaluation showed that several isolated cucurbitane-type triterpene glycosides had antiproliferative activities against MCF-7, WiDr, HEp-2, and Doay human tumor cell lines. In addition, compound 14 showed potent hypoglycemic activities by glucose uptake assay. PMID:23432055

Hsiao, Ping-Chun; Liaw, Chia-Ching; Hwang, Syh-Yuan; Cheng, Hui-Ling; Zhang, Li-Jie; Shen, Chien-Chang; Hsu, Feng-Lin; Kuo, Yao-Haur

2013-03-12

441

Two new flavonol glycosides from the Tibetan medicinal plant Aconitum tanguticum.  

PubMed

Two new flavonol glycosides characterized as quercetin 3-O-?-l-rhamnopyranosyl-(1 ? 2)-[?-d-glucopyranosyl-(1 ? 3)-?-l-(4-O-trans-p-coumaroylrhamnopyranosyl)-(1 ? 6)]-?-d-galactopyranoside-7-O-?-l-rhamnopyranoside (1) and kaempferol 3-O-?-l-rhamnopyranosyl-(1 ? 2)-[?-d-glucopyranosyl-(1 ? 3)-?-l-(4-O-trans-p-coumaroyl rhamnopyranosyl)-(1 ? 6)]-?-d-galactopyranoside-7-O-?-l-rhamnopyranoside (2), together with two known flavonol glycosides quercetin 3-O-?-l-rhamnopyranosyl-(1 ? 2)- [?-l-rhamnopyranosyl-(1 ? 6)]-?-d-galactopyranoside-7-O-?-l-rhamnopyranoside (3) and kaempferol 3-O-?-l-rhamnopyranosyl-(1 ? 2)-[?-l-rhamnopyranosyl-(1 ? 6)]-?-d-galactopyranoside-7-O-?-l-rhamnopyranoside (4), were isolated from the whole plant of Aconitum tanguticum (Maxim.) Stapf. The structures of the new compounds were elucidated by spectroscopic methods, and the total (1)H and (13)C NMR chemical shifts were assigned. PMID:23767974

Xu, Lu; Zhang, Xiao; Lin, Li-Mei; Li, Chun; Wang, Zhi-Min; Luo, Yong-Ming

2013-06-14

442

Structural elucidation of dextran degradation mechanism by streptococcus mutans dextranase belonging to glycoside hydrolase family 66.  

PubMed

Dextranase is an enzyme that hydrolyzes dextran ?-1,6 linkages. Streptococcus mutans dextranase belongs to glycoside hydrolase family 66, producing isomaltooligosaccharides of various sizes and consisting of at least five amino acid sequence regions. The crystal structure of the conserved fragment from Gln(100) to Ile(732) of S. mutans dextranase, devoid of its N- and C-terminal variable regions, was determined at 1.6 Ĺ resolution and found to contain three structural domains. Domain N possessed an immunoglobulin-like ?-sandwich fold; domain A contained the enzyme's catalytic module, comprising a (?/?)(8)-barrel; and domain C formed a ?-sandwich structure containing two Greek key motifs. Two ligand complex structures were also determined, and, in the enzyme-isomaltotriose complex structure, the bound isomaltooligosaccharide with four glucose moieties was observed in the catalytic glycone cleft and considered to be the transglycosylation product of the enzyme, indicating the presence of four subsites, -4 to -1, in the catalytic cleft. The complexed structure with 4',5'-epoxypentyl-?-d-glucopyranoside, a suicide substrate of the enzyme, revealed that the epoxide ring reacted to form a covalent bond with the Asp(385) side chain. These structures collectively indicated that Asp(385) was the catalytic nucleophile and that Glu(453) was the acid/base of the double displacement mechanism, in which the enzyme showed a retaining catalytic character. This is the first structural report for the enzyme belonging to glycoside hydrolase family 66, elucidating the enzyme's catalytic machinery. PMID:22337884

Suzuki, Nobuhiro; Kim, Young-Min; Fujimoto, Zui; Momma, Mitsuru; Okuyama, Masayuki; Mori, Haruhide; Funane, Kazumi; Kimura, Atsuo

2012-02-15

443

17-Hydroxygeranyllinalool glycosides are major resistance traits of Nicotiana obtusifolia against attack from tobacco hornworm larvae.  

PubMed

In the Great Basin Desert, Nicotiana obtusifolia (synonymous with Nicotiana trigonophylla) and Nicotiana attenuata co-occur, but the former is frequently less attacked by larvae of the tobacco hornworm than the latter, despite having lower nicotine and trypsin protease inhibitor defenses. Glycosides of the diterpene, 17-hydroxygeranyllinalool (HGL-DTGs) have recently been found to be important defenses of N. attenuata. Total HGL-DTG levels are 5-fold higher in N. obtusifolia than in N. attenuata, and we characterize the three major HGL-DTGs purified from N. obtusifolia leaves as: 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-17-hydroxygeranyllinalool-17-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranoside; nicotinoside III and its malonic acid conjugates. Using APCI- and ESI-LC-MS, we also identified mono- and diacetyl-nicotinoside III and quercetin glycosides. To evaluate the defensive value of these HGL-DTGs, we used virus-induced-gene silencing to reduce the transcript levels of geranylgeranyl diphosphate synthase and total HGL-DTG levels in both species. When fed on silenced plants, larvae gained up to about two times more mass than those that fed on empty vector control plants of both species. We conclude that HGL-DTGs function as the most important direct defenses for both N. attenuata and N. obtusifolia. PMID:20452633

Jassbi, Amir Reza; Zamanizadehnajari, Simin; Baldwin, Ian T

2010-05-07

444

[Inhibition of adherence of Corynebacterium diphtheriae to human buccal epithelium by glycoside hydrolases from marine hydrobiontes].  

PubMed

A possibility of adhesion inhibition of Corynebacterium diphtheriae to human buccal epithelium by glycoside hydrolases of marine hydrobiontes was investigated using alpha-galactosidase from marine bacterium Pseudoalteromonas sp. KMM 701, total enzyme preparation and beta-1,3-glucanase from marine fungi Chaetomium, total enzyme preparation and beta-1,3-glucanase from marine mollusk Littorina kurila, and total enzyme preparation from crystalline style of marine mollusk Spisula sachalinensis were used. The enzymes were added to test-tubes containing buccal epithelial cells and/or the toxigenic bacterial strain C. diphtheriae No 1129, v. gravis. All the investigated enzymes were able to abort C. diphtheriae adherence, to human buccal epithelocytes. Inhibition of adhesion was more pronounced in the case of treatment of epithelocytes with highly purified enzymes of marine hydrobiontes in comparison with total enzyme preparations. The significant inhibition of C. diphtheriae adhesion was observed when the enzymes were added to the epithelocytes with the attached microorganisms. The results obtained show that glycoside hydrolases of marine hydrobiontes degrade any carbohydrates expressed on cell surface of bacterium or human buccal epithelocytes, impair unique lectin-carbohydrate interaction and prevent the adhesion. PMID:20695214

Zaporozhets, T S; Makarenkova, I D; Bakunina, I Iu; Burtseva, Iu V; Kusa?kin, M I; Balabanova, L A; Zviagintseva, T N; Besednova, N N; Rasskazov, V A

445

Effects of verbascoside, a phenylpropanoid glycoside from lemon verbena, on phospholipid model membranes.  

PubMed

Phenylpropanoid glycosides are water-soluble compounds widely distributed, most of them deriving from medicinal herbs. Among them, verbascoside or acteoside has exhibited a wide biological activity, being free radical scavenging the most representative one. Moreover, antitumor, antimicrobial, anti-inflammatory, anti-thrombotic and wound healing properties have been previously described. Herein, the interaction of verbascoside with phospholipid membranes has been studied by means of differential scanning calorimetry, fluorescence anisotropy and dynamic light scattering. Verbascoside showed stronger affinity for negatively charged membranes composed of phosphatidylglycerol (PG) than for phosphatidylcholine (PC) membranes. This compound promoted phase separation of lipid domains in PC membranes and formed a stable lipid complex with and approximate phospholipid/verbascoside ratio of 4:1. Despite its hydrophilic character, verbascoside's caffeoyl moiety was located deep into the hydrophobic core of PC membranes and was almost inaccessible to spin probes located at different depths in PG membranes. This compound affected the ionization behavior of the PG phosphate group and most likely interacted with the vesicles surface. The presence of verbascoside decreased the particle size in PG unilamellar vesicles through the increase of the phospholipid head group area. A localization of verbascoside filling the upper region of PG bilayers close to the phospholipid/water interface is proposed. These effects on membranes may help to understand the mechanism of the biological activity of verbascoside and other similar phenylpropanoid glycosides. PMID:19925782

Funes, Lorena; Laporta, Olga; Cerdán-Calero, Manuela; Micol, Vicente

2009-11-17

446

Pretreatment of baicalin and wogonoside with glycoside hydrolase: A promising approach to enhance anticancer potential.  

PubMed

Previous phytochemical studies showed that the major flavonoids in Scutellaria baicalensis are baicalin, baicalein, wogonoside and wogonin. The two glycosides (baicalin and wogonoside) can be transformed into their aglycons (baicalein and wogonin), which possess positive anticancer potential. In this study, we used glycosidase to catalyze flavonoids in S. baicalensis to enhance the herb's anticancer activities. Our HPLC data showed that, using the optimized conditions obtained in our experiments (20 U/g of cellulase, 50?C, pH 4.8 and treatment for 8 h), there was a marked transformation from the two glycosides to their aglycons. The anticancer activity was subsequently evaluated using a series of S. baicalensis extracts in which variable lengths of glycosidase treatment time were used. Combining analytical and bioassay results, we observed that the higher the aglycon content, the stronger the antiproliferation effects. Compared to the untransformed control, 8 h of glycosidase catalyzing significantly increased antiproliferative activity on human colorectal and breast cancer cells, and its cancer cell growth inhibition is, in part, mediated by cell cycle arrest at the S-phase and induction of apoptosis. Data from this study suggest that using glycosidase to catalyze S. baicalensis offers a promising approach to increase its anticancer activity. PMID:24026776

Yu, Chunhao; Zhang, Zhiyu; Zhang, Haijiang; Zhen, Zhong; Calway, Tyler; Wang, Yunwei; Yuan, Chun-Su; Wang, Chong-Zhi

2013-09-09

447

Flavonol glycosides acylated with 3-hydroxy-3-methylglutaric acid as systematic characters in Rosa.  

PubMed

LC-UV-MS/MS analysis of leaf extracts from 146 accessions of 71 species of Rosa revealed that some taxa accumulated flavonol O-glycosides acylated with 3-hydroxy-3-methylglutaric acid, which are relatively uncommon in plants. The structures of two previously unrecorded examples isolated from Rosa spinosissima L. (syn. Rosa pimpinellifolia L.) were elucidated using spectroscopic and chemical methods as the 3-O-?-L-rhamnopyranosyl-(1?2)-[6-O-(3-hydroxy-3-methylglutaryl)-?-D-galactopyranosides] of kaempferol (3,5,7,4'-tetrahydroxyflavone) and quercetin (3,5,7,3',4'-pentahydroxyflavone). The corresponding 3-O-[6-O-(3-hydroxy-3-methylglutaryl)-?-D-galactopyranoside] of quercetin was also present in R. spinosissima, but at lower levels, together with 17 other flavonol O-glycosides for which structures were assigned using LC-UV-MS/MS. The distribution of flavonol 3-hydroxy-3-methylglutarylgalactosides in Rosa was limited to some species of subgenus Rosa section Pimpinellifoliae and Rosa roxburghii Sw. of the monotypic subgenus Platyrhodon, indicating that this character could be of value in phylogenetic analyses of the genus. PMID:22721781

Porter, Elaine A; van den Bos, Alexander A; Kite, Geoffrey C; Veitch, Nigel C; Simmonds, Monique S J

2012-06-20

448

Cyanogenic glycosides in plant-based foods available in New Zealand.  

PubMed

Cyanogenic glycosides occur in a wide range of plant species. The potential toxicity of cyanogenic glycosides arises from enzymatic degradation to produce hydrogen cyanide, which may result in acute cyanide poisoning and has also been implicated in the aetiology of several chronic diseases. One hundred retail foods were sampled and analysed for the presence of total hydrocyanic acid using an acid hydrolysis-isonicotinic/barbituric acid colourimetric method. Food samples included cassava, bamboo shoots, almonds and almond products, pome fruit products, flaxseed/linseed, stone fruit products, lima beans, and various seeds and miscellaneous products, including taro leaves, passion fruit, spinach and canned stuffed vine leaves. The concentrations of total hydrocyanic acid (the hydrocyanic acid equivalents of all cyanogenic compounds) found were consistent with or lower than concentrations reported in the scientific literature. Linseed/flaxseed contained the highest concentrations of total hydrocyanic acid of any of the analysed foods (91-178 mg kg(-1)). Linseed-containing breads were found to contain total hydrocyanic acid at concentrations expected from their linseed content, indicating little impact of processing on the total hydrocyanic acid content. Simulation modelling was used to assess the risk due to the total hydrocyanic acid in fruit juice and linseed-containing bread.  PMID:23984870

Cressey, Peter; Saunders, Darren; Goodman, Janet

2013-08-28

449

Rehabilitation of faulty kinetic determinations and misassigned glycoside hydrolase family of retaining mechanism ?-xylosidases.  

PubMed

We obtained Cx1 from a commercial supplier, whose catalog listed it as a ?-xylosidase of glycoside hydrolase family 43. NMR experiments indicate retention of anomeric configuration in its reaction stereochemistry, opposing the assignment of GH43, which follows an inverting mechanism. Partial protein sequencing indicates Cx1 is similar to but not identical to ?-xylosidases of GH52, including Q09LZ0, that have retaining mechanisms. Q09LZ0 ?-xylosidase had been characterized biochemically in kinetic reactions that contained Tris. We overproduced Q09LZ0 and demonstrated that Tris is a competitive inhibitor of the ?-xylosidase. Also, the previous work used grossly incorrect extinction coefficients for product 4-nitrophenol. We redetermined kinetic parameters using reactions that omitted Tris and using correct extinction coefficients for 4-nitrophenol. Cx1 and Q09LZ0 ?-xylosidases were thus shown to possess similar kinetic properties when acting on 4-nitrophenyl-?-d-xylopyranoside and xylobiose. kcat pH profiles of Cx1 and Q09LZ0 acting on 4-nitrophenyl-?-d-xylopyranoside and xylobiose have patterns containing two rate increases with increasing acidity, not reported before for glycoside hydrolases. The dexylosylation step of 4-nitrophenyl-?-d-xylopyranoside hydrolysis mediated by Q09LZ0 is not rate determining for kcat(4NPX). PMID:23916587

Jordan, Douglas B; Vermillion, Karl E; Grigorescu, Arabela A; Braker, Jay D

2013-08-02

450

Protective effect of total phenylethanoid glycosides from Monochasma savatieri Franch on myocardial ischemia injury.  

PubMed

The present study was designed to investigate the cardioprotective effect of total phenylethanoid glycosides from Monochasma savatieri Franch (TPG). The data showed that there were mainly four phenylethanoid glycosides isolated and identified from TPG. TPG significantly increased cells viability and inhibited morphological changes on H9c2 cardiomyocytes induced by H2O2 or Na2S2O4. In addition, TPG significantly decreased T-wave elevation and histopathological changes of heart tissues in myocardial infracted rats induced by isoproterenol. It also significantly reduced the infarct size induced by ligating the coronary artery in rats, increased the activities of antioxidative enzymes superoxide dismutase (SOD), the content of glutathione (GSH), and decreased the leakage of lactic dehydrogenase (LDH), the activities of creatine kinase (CK) and the content of maleic dialdehyde (MDA). In conclusion, these results suggested that TPG from Monochasma savatieri Franch might be developed as new natural medicine or food additives with effects of prevention of coronary artery disease due to its significant antioxidant activity. PMID:23880328

Shi, Mengfan; He, Wenjun; Liu, Yanli; Li, Xiaoran; Yang, Shilin; Xu, Qiongming

2013-07-20

451

Adsorption properties and preparative separation of phenylethanoid glycosides from Cistanche deserticola by use of macroporous resins.  

PubMed

A simple and efficient chromatographic method for large-scale preparative separation of phenylethanoid glycosides (mainly contain echinacoside and acteoside) from Cistanche deserticola was developed. The adsorption properties of eight macroporous resins were evaluated. Three selected resins were further screened depending on the adsorption kinetics curves, in which HPD300 resin showed the best separation efficiency. The adsorption isotherm data on HPD300 resin were fitted to the Freundlich equation in certain concentration range. The dynamic adsorption and desorption experiments were carried out on columns packed with HPD300 resin to optimize the separation process. The breakthrough curves showed that acteoside had a higher affinity to the resin than echinacoside. The contents of echinacoside and acteoside in the product increased from 1.79% and 1.43% in the crude extracts to 16.66% and 15.17%, with recovery yields of 80.41% and 90.17%, respectively. The purity of total phenylethanoid glycosides in the product was 76.58%. PMID:24022055

Liu, Boyan; Ouyang, Jie; Yuan, Xiaofan; Wang, Liwei; Zhao, Bing

2013-08-18

452

Defining the Polar Field Reversal  

NASA Astrophysics Data System (ADS)

The polar fields on the Sun are directly related to solar cycle variability. Recently there has been interest in studying an important characteristic of the polar fields: the timing of the polar field reversals. However this characteristic has been poorly defined, mostly due to the limitations of early observations. In the past, the reversals have been calculated by averaging the flux above some latitude (i.e. 55° or 75°). Alternatively, the reversal could be defined by the time in which the previous polarity is completely canceled and replaced by the new polarity at 90°, precisely at the pole. We will use a surface flux transport model to illustrate the differences in the timing of the polar field reversal based on each of these definitions and propose standardization in the definition of the polar field reversal. The ability to predict the timing of the polar field reversal using a surface flux transport model will also be discussed.

Upton, Lisa; Hathaway, D. H.

2013-07-01

453

A Universal Reversible Turing Machine  

Microsoft Academic Search

A reversible Turing machines is a computing model with a “backward deterministic” property, which is closely related to physical\\u000a reversibility. In this paper, we study the problem of finding a small universal reversible Turing machine (URTM). As a result,\\u000a we obtained a 17-state 5-symbol URTM in the quintuple form that can simulate any cyclic tag system.

Kenichi Morita; Yoshikazu Yamaguchi

2007-01-01

454

Time Reversal of Electromagnetic Waves  

Microsoft Academic Search

We report the first experimental demonstration of time-reversal focusing with electromagnetic waves. An antenna transmits a 1-mus electromagnetic pulse at a central frequency of 2.45GHz in a high-Q cavity. Another antenna records the strongly reverberated signal. The time-reversed wave is built and transmitted back by the same antenna acting now as a time-reversal mirror. The wave is found to converge

G. Lerosey; J. de Rosny; A. Tourin; A. Derode; G. Montaldo; M. Fink

2004-01-01

455

Stereoselective synthesis of 2-deoxy-2-iodo-glycosides from furanoses. A new route to 2-deoxy-glycosides and 2-deoxy-oligosaccharides of ribo and xylo configuration.  

PubMed

[reaction: see text] A general procedure for the stereoselective synthesis of 2-deoxy-2-iodo-hexo- and -hepto-pyranosyl glycosides from furanoses is reported. The proposed methodology provides a new route for accessing 2-deoxy-oligosaccharides. The procedure involves three reactions: Wittig-Horner olefination to give alkenyl sulfanyl derivatives, electrophilic iodine-induced cyclization to give phenyl 2-deoxy-2-iodo-1-thio-hexo-glycosides, and glycosylation. Protected furanoses 1, 3, and 6-11, which include examples of the four possible isomeric configurations of furanoses, were reacted with diphenyl phenylsulfanylmethyl phosphine oxide to give the alkenyl sulfanyl derivatives 2, 4, and 12-16. The iodine-induced cyclization of these compounds afforded the phenyl 2-deoxy-2-iodo-1-thio-glycosides 18, 20, and 22-27 with practically complete regio- and stereoselectivity. Products of 6-endo cyclization, in which the iodine at C-2 was in a cis relationship with the alkoxy at C-3, were almost exclusively produced. Better yields were obtained for compounds with a ribo or xylo configuration than for compounds with other configurations. Compounds 18, 20, and 22-27 were found to be efficient glycosyl donors in the glycosylation of cholesterol and glucopyranoside 29a, affording the corresponding 2-deoxy-2-iodo-glycosides and 2-deoxy-2-iodo-oligosaccharides with good yields and stereoselectivities. The glycosydic bond in the major isomers was always trans to the iodine at C-2. PMID:16323838

Rodríguez, Miguel Angel; Boutureira, Omar; Arnés, Xavier; Matheu, M Isabel; Díaz, Yolanda; Castillón, Sergio

2005-12-01

456

[Posterior reversible encephalopathy syndrome].  

PubMed

INTRODUCTION: Reversible Posterior Leukoencephalopathy Syndrome was introduced into clinical practice in 1996 in order to describe unique syndrome, clinically expressed during hypertensive and uremic encephalopathy, eclampsia and during immunosuppressive therapy [1]. First clinical investigations showed that leucoencephalopathy is major characteristic of the syndrome, but further investigations showed no significant destruction in white cerebral tissue [2, 3, 4]. In majority of cases changes are localise in posterior irrigation area of the brain and in the most severe cases anterior region is also involved. Taking into consideration all above mentioned facts, the suggested term was Posterior Reversible Encephalopathy Syndrome (PRES) for the syndrome clinically expressed by neurological manifestations derived from cortical and subcortical changes localised in posterior regions of cerebral hemispheres, cerebral trunk and cerebellum [5]. CASE REPORT: Patient, aged 53 years, was re-hospitalized in Cardiovascular Institute "Dediwe" two months after successful aorto-coronary bypass performed in June 2001 due to the chest bone infection. During the treatment of the infection (according to the antibiogram) in September 2001, patient in evening hours developed headache and blurred vision. The recorded blood pressure was 210/120 mmHg so antihypertensive treatment was applied (Nifedipin and Furosemid). After this therapy there was no improvement and intensive headache with fatigue and loss of vision developed. Neurological examination revealed cortical blindness and left hemiparesis. Manitol (20%, 60 ccm every 3 hours) and i.v. Nytroglicerin (high blood pressure). Brain CT revealed oedema of parieto-occipital regions of both hemispheres, more emphasized on the right. (Figure 1a, b, c). There was no sign of focal ischemia even in deeper sections (Figure 1d, e, f). Following three days enormous high blood pressure values were registered. On the fourth day the significant clinical improvement occurred with lowering of blood pressure, better mental state and better vision. There was no sign of left hemiparesis on the 7th day. On the 9th day there were no symptoms or sign of disease. Control brain CT (15th day) was normal. ETHIOPATHOGENESIS: Most common causes of PRES are hypertensive encephalopathy [6-8], pre-eclampsia/eclampsia [9-12] cyclosporin A administration [13-22] and uremic encephalopathy [23]. There are several theories about the mechanism for PRES in hypertensive encephalopathy (reversible vasospasm and hyperperfusion) and administration of cyclosporin A (neurotoxic effect). CLINICAL PICTURE: Most common symptoms are headache, nausea, vomiting, confusion, behavioural changes, changes of conciousness (from somnolencia to stupor), vision disturbances (blurred vision, haemianopsia, cortical blindness) and epileptic manifestations (mostly focal attacks with secondary generalisation). Mental functions are characterised with decreased activity and reactivity, confusion, loss of concentration and mild type of amnesia. Lethargy is often initial sign, sometimes accompanied with phases of agitation. Stupor and coma rarely occurred. DIAGNOSIS: In patients with hypertensive encephalopathy and eclampsia high blod pressure is registered. Neurological examination revealed vision changes and damages of mental function as well as increased reflex activity. Today, brain MRI and CT are considered the most important diagnostic method for the diagnosis and follow-up of patients with PRES [6]. Brain MRI better detects smaller focal parenhim abnormalities than brain CT. The most often neuroradiological finding is relatively symmetrical oedema of white cerebral tissue in parieto-occipital regions of both cerebral hemispheres. Gray cerebral tissue is sometimes involved, usually in mild form of disease. Diagnosis of this "cortical" form of PRES is possible by MR FLAIR (Fluid-Attenuated Inversion Recovery) technique [5]. TREATMENT: Therapeutic strategy depends on the cause of PRES and clinical picture. Most important are blood pres

Petrovi?, Branko; Kosti?, Vladimir; Sterni?, Nadezda; Kolar, Jovo; Tasi?, Nebojsa

457

Stereoisomeric separation of flavanones and flavanone-7-O-glycosides by capillary electrophoresis and determination of interconversion barriers.  

PubMed

The stereoisomeric separation of several flavanones and flavanone-7-O-glycosides has been achieved with capillary electrophoresis by adding native cyclodextrins or cyclodextrin derivatives to the background electrolyte. As an alternative method, micellar electrokinetic chromatography with sodium cholate as a chiral surfactant has been used for the epimeric separation of two flavanone-7-O-glycosides. The effect of buffer systems containing mixtures of cyclodextrin with either sodium dodecyl sulfate or sodium cholate upon the chiral recognition of flavanones and flavanone-7-O-glycosides as well as the variation of the background electrolyte (concentration of buffer and surfactant, pH value, organic modifier), and its influence on the resolution factor Rs was investigated. Temperature- and pH-dependent enantiomerization or epimerization barriers of several flavanones (naringenin, homoeriodictyol) and flavanone-7-O-glycosides (naringin, neohesperidin, prunin, narirutin) in basic media (pH values of 9-11) have been observed. Interconversion profiles featuring characteristic plateau formation of the elution pattern were observed at high pH and evaluated with the simulation software ChromWin to determine rate constants k(T) and Eyring activation parameters, DeltaG#(T), DeltaH#, and DeltaS#. PMID:16689546

Wistuba, Dorothee; Trapp, Oliver; Gel-Moreto, Nuria; Galensa, Rudolf; Schurig, Volker

2006-05-15

458

Chiral separation of six diastereomeric flavanone-7- O-glycosides by capillary electrophoresis and analysis of lemon juice  

Microsoft Academic Search

The diastereomers of six major flavanone-7-O-glycosides (naringin, prunin, narirutin, hesperidin, neohesperidin and eriocitrin) were completely separated for the first time by chiral capillary electrophoresis (CE) employing various buffers and chiral selectors on the basis of the results achieved in 1998 in our research group by Mellenthin. The following chiral additives to the background electrolyte (BGE) were examined: native cyclodextrins (CDs;

Nuria Gel-Moreto; René Streich; Rudolf Galensa

2001-01-01

459

Protective effects of flavonols and their glycosides against free radical-induced oxidative hemolysis of red blood cells  

Microsoft Academic Search

The in vitro oxidative hemolysis of human red blood cells (RBCs) was used as a model to study the free radical-induced damage of biological membranes and the protective effect of flavonols and their glycosides (FOHs), i.e., myricetin (MY), quercetin (Q), morin (MO), kaempferol (K), rutin (R), quercetin galactopyranoside (QG), quercetin rhamnopyranoside (QR), and kaempferol glucopyranoside (KG). The hemolysis of RBCs

Fang Dai; Qing Miao; Bo Zhou; Li Yang; Zhong-Li Liu

2006-01-01

460

Melanogenesis inhibitory activities of iridoid-, hemiterpene-, and fatty acid-glycosides from the fruits of Morinda citrifolia (Noni).  

PubMed

A new iridoid glycoside, 9-epi-6alpha-methoxy geniposidic acid (4), three new hemiterpene glycosides, 3-methylbut-3-enyl 2'-O-(beta-D-glucopyranosyl)-beta-D-glucopyranoside (nonioside K) (6), 3-methylbut-3-enyl 6'-O-(beta-D-xylopyranosyl)-beta-D-glucopyranoside (nonioside L) (8), and 3-methylbut-3-enyl 6'-O-(beta-D-xylofuranosyl)-beta-D-glucopyranoside (nonioside M) (9), and two new saccharide fatty acid esters, 6'-O-(beta-D-glucopyranosyl)-1'-O-[(2xi)-2-methylbutanoyl]-beta-D-glucopyranose (nonioside N) (16) and 6'-O-(beta-D-xylopyranosyl)-1'-O-[(2xi)-2-methylbutanoyl]-beta-D-glucopyranose (nonioside O) (17), were isolated from a methanol extract of the fruits of Morinda citrifolia (noni), along with 11 known compounds, namely, three iridoid glycosides (1-3), two hemiterpene glycosides (5 and 7), and five saccharide fatty acid esters (10-15). Upon evaluation of compounds 1-17 on the melanogenesis in the B16 melanoma cells induced with alpha-melanocyte-stimulating hormone (alpha-MSH), 13 compounds (1, 3, 4, 6-14, and 17) exhibited marked inhibitory effects with 34-49% reduction of melanin content at 100 muM with no or almost no toxicity to the cells (91-116% of cell viability at 100 microM). PMID:20032599

Akihisa, Toshihiro; Seino, Ken-ichi; Kaneko, Etsuyo; Watanabe, Kensuke; Tochizawa, Shun; Fukatsu, Makoto; Banno, Norihiro; Metori, Koichi; Kimura, Yumiko

2010-01-01

461

Cardiac glycosides provide neuroprotection against ischemic stroke: Discovery by a brain slice-based compound screening platform  

Microsoft Academic Search

We report here the results of a chemical genetic screen using small molecules with known pharmacologies coupled with a cortical brain slice-based model for ischemic stroke. We identified a small-molecule compound not previously appreciated to have neuroprotective action in ischemic stroke, the cardiac glycoside neriifolin, and demonstrated that its properties in the brain slice assay included delayed therapeutic potential exceeding

James K. T. Wang; Stuart Portbury; Mary Beth Thomas; Shawn Barney; Daniel J. Ricca; Dexter L. Morris; David S. Warner; Donald C. Lo

2006-01-01

462

Three unusual 22-beta-O-23-hydroxy-(5 alpha)-spirostanol glycosides from the fruits of Solanum torvum.  

PubMed

Three novel 22-beta-O-spirostanol oligoglycosides, torvosides J (1), K (2) and L (3) have been isolated from the fruits of Solanum torvum SWARTZ and their chemical structures have been characterized based on the spectroscopic means. They are worth of note as rare 22-beta-O-spirostanol glycosides. PMID:16141580

Iida, Yoshihiko; Yanai, Yoshihiro; Ono, Masateru; Ikeda, Tsuyoshi; Nohara, Toshihiro

2005-09-01

463

INFLUENCE OF GLYCOSIDIC LINKAGES AND MOLECULAR WEIGHT ON THE FERMENTATION OF MALTOSE-BASED OLIGOSACCHARIDES BY GUT BACTERIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

A structure-function study was carried out to increase knowledge of how glycosidic linkages and molecular weight of carbohydrates contribute towards the selectivity of fermentation by gut bacteria. Oligosaccharides with maltose as the common carbohydrate source were used. Potentially prebiotic alt...

464

Effect of hostplant genotype and predators on iridoid glycoside content of pupae of a specialist insect herbivore, Junonia coenia (Nymphalidae)  

Microsoft Academic Search

Two field experiments assessed the effects of hostplant genotype, presence or absence of predators, and type of predator on chemical content of pupae of the Buckeye butterfly, Junonia coenia (Nymphalidae). When fed Plantago lanceolata (Plantaginaceae), J. coenia larvae sequester two iridoid glycosides, aucubin and catalpol, which are retained into the pupal stage. In the first experiment, it is found that

M. Deane Bowers; Nancy E. Stamp

1997-01-01

465

Electron Impact Ion Fragmentation Pathways of Peracetylated C-glycoside Ketones Derived from Cyclic 1,3-diketones  

Technology Transfer Automated Retrieval System (TEKTRAN)

Monosaccharide C-glycoside ketones have been prepared by aqueous-based Knoevenagel condensation of isotopically-labeled and unlabeled aldoses with cyclic diketones, 5,5-dimethyl-1,3-cyclohexanedione (dimedone) and 1,3-cyclohexanedione (1,3-CHD). The reaction products and their corresponding acetyla...

466

Determination of six steviol glycosides of Stevia rebaudiana (Bertoni) from different geographical origin by LC-ESI-MS/MS.  

PubMed

Liquid chromatography electro-spray tandem mass spectrometry (LC-ESI/MS/MS) was applied to the determination of sweet glycosides (steviol glycosides), and toxic aglycon steviol in 24 samples of Stevia rebaudiana (Bertoni) aerial parts, which had been experimentally cultivated in Italy, although derived from seeds of different geographical origin. On the basis of the specific fragmentation of these compounds, an LC-MS/MS method was developed with the aim of quantifying analytes in plant material. Although toxic steviol was not detectable in all the samples, the samples with the highest levels of steviol glycosides were identified. Analysis of the different samples revealed that they were good quality samples, quality being directly linked to the presence of sweet glycosides in the plants cultivated in Italy, although there were differences in the content of these compounds according to the origin of the seeds, and in particular, a major concentration of compounds with major sweetness activity and minor toxicity was found in the population coming from Brazil (for example: sample 10, stevioside content 15.74±2.0% p/p and rebaudioside A content 3.09±0.39% p/p of dried plant). Finally, based on this metabolomic targeted approach, the results obtained for the samples were treated by Principal Component Analysis, identifying specific genotypic differences based on the geographic origin of the seeds. PMID:23790843

Montoro, Paola; Molfetta, Ilaria; Maldini, Mariateresa; Ceccarini, Lucia; Piacente, Sonia; Pizza, Cosimo; Macchia, Mario

2013-03-21

467

A new group of exo-acting family 28 glycoside hydrolases of Aspergillus niger that are involved in pectin degradation  

Microsoft Academic Search

The fungus Aspergillus niger is an industrial producer of pectin degrading enzymes. The recent solving of the genomic sequence of A. niger allowed an inventory of the entire genome of the fungus for potential carbohydrate degrading enzymes. By applying bioinformatics tools 12 new genes putatively encoding family 28 glycoside hydrolases were identified. Seven of the newly discovered genes form a

Hanem Awad; Gerrit Beldman; Berg van den J. A

2006-01-01

468

A variety of lipid-coated glycoside hydrolases as effective glycosyl transfer catalysts in homogeneous organic solvents  

Microsoft Academic Search

Various lipid-coated glycoside hydrolases were prepared, which act as efficient catalysts for transglycosylation of ?-D- and ?-D-mannoside, N-acetyl-?-D-glucosaminide, ?-D-glucoside, and ?-D-galactoside to hydrophobic acceptor alcohols in dry isopropyl ether. The enzyme activity for the glycosylation depended on coating lipids as well as origin or kind of enzymes.

Toshiaki Mori; Yoshio Okahata

1997-01-01

469

Identification of the conserved spatial position of key active-site atoms in glycoside hydrolase 13 family members  

Microsoft Academic Search

A computational study on the glycoside hydrolase 13 (GH13) family of the CAZy database has been carried out at the atomic level in order to identify the conserved positions that may be responsible for recognition of the substrate. Analysis with substrate analog-, inhibitor-, or product-bound 3D structures was carried out to find the atomic spatial arrangement of the amino acids

Vikash Kumar

2010-01-01

470

Identification of polyoxypregnane glycosides from the stems of Marsdenia tenacissima by high-performance liquid chromatography/tandem mass spectrometry.  

PubMed

A facile method based on high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC/(+)ESI-MS(n)) has been established for the analysis of polyoxypregnane glycosides in the stems of Marsdenia tenacissima. The data reveals the ability of MS(n) in the structural elucidation of polyoxypregnane glycosides including the nature of the polyoxypregnane core, the kinds of the substituents and the types of sugar residues. Offline Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) is also performed to assign accurate elemental compositions. In this study, eighteen polyoxypregnane glycosides have been investigated. Among these components, five compounds are unambiguously identified as Marsdenoside K, Tencissoside A, B, C and D; two compounds are established as novel compounds based on mass spectral data; and the other eleven compound's structures are tentatively proposed. Furthermore, breakdown curves are constructed to distinguish five pairs of isomers among these eighteen compounds. As far as our knowledge, this is the first report on identification of polyoxypregnane glycosides in the stems of M. tenacissima by HPLC/ESI-MS(n) directly, which could save time and material consuming efforts in traditional phytochemistry analyses. PMID:18804613

Chen, Juanjuan; Li, Xiaoyu; Sun, Cuirong; Pan, Yuanjiang; Schlunegger, Urs Peter

2008-06-08

471

Reversible micromachining locator  

DOEpatents

This invention provides a device which includes a locator, a kinematic mount positioned on a conventional tooling machine, a part carrier disposed on the locator and a retainer ring. The locator has disposed therein a plurality of steel balls, placed in an equidistant position circumferentially around the locator. The kinematic mount includes a plurality of magnets which are in registry with the steel balls on the locator. In operation, a blank part to be machined is placed between a surface of a locator and the retainer ring (fitting within the part carrier). When the locator (with a blank part to be machined) is coupled to the kinematic mount, the part is thus exposed for the desired machining process. Because the locator is removably attachable to the kinematic mount, it can easily be removed from the mount, reversed, and reinserted onto the mount for additional machining. Further, the locator can likewise be removed from the mount and placed onto another tooling machine having a properly aligned kinematic mount. Because of the unique design and use of magnetic forces of the present invention, positioning errors of less than 0.25 micrometer for each machining process can be achieved.

Salzer, Leander J. (Los Alamos, NM); Foreman, Larry R. (Los Alamos, NM)

1999-01-01

472

Reversible micromachining locator  

DOEpatents

This invention provides a device which includes a locator, a kinematic mount positioned on a conventional tooling machine, a part carrier disposed on the locator and a retainer ring. The locator has disposed therein a plurality of steel balls, placed in an equidistant position circumferentially around the locator. The kinematic mount includes a plurality of magnets which are in registry with the steel balls on the locator. In operation, a blank part to be machined is placed between a surface of a locator and the retainer ring (fitting within the part carrier). When the locator (with a blank part to be machined) is coupled to the kinematic mount, the part is thus exposed for the desired machining process. Because the locator is removably attachable to the kinematic mount, it can easily be removed from the mount, reversed, and reinserted onto the mount for additional machining. Further, the locator can likewise be removed from the mount and placed onto another tooling machine having a properly aligned kinematic mount. Because of the unique design and use of magnetic forces of the present invention, positioning errors of less than 0.25 micrometer for each machining process can be achieved. 7 figs.

Salzer, L.J.; Foreman, L.R.

1999-08-31

473

Time Reversal Violation  

SciTech Connect

This talk briefly reviews three types of time-asymmetry in physics, which I classify as universal, macroscopic and microscopic. Most of the talk is focused on the latter, namely the violation of T-reversal invariance in particle physics theories. In sum tests of microscopic T-invariance, or observations of its violation, are limited by the fact that, while we can measure many processes, only in very few cases can we construct a matched pair of process and inverse process and observe it with sufficient sensitivity to make a test. In both the cases discussed here we can achieve an observable T violation making use of flavor tagging, and in the second case also using the quantum properties of an antisymmetric coherent state of two B mesons to construct a CP-tag. Both these tagging properties depend only on very general properties of the flavor and/or CP quantum numbers and so provide model independent tests for T-invariance violations. The microscopic laws of physics are very close to T-symmetric. There are small effects that give CP- and T-violating processes in three-generation-probing weak decays. Where a T-violating observable can be constructed we see the relationships between T-violation and CP-violation expected in a CPT conserving theory. These microscopic effects are unrelated to the 'arrow of time' that is defined by increasing entropy, or in the time direction defined by the expansion of our Universe.

Quinn, H; /SLAC

2009-01-27

474

Reversibility of liver fibrosis  

PubMed Central

Liver fibrosis, and its end stage cirrhosis are a major cause of morbidity and mortality and therapeutic options are limited. However, the traditional view of liver disease as an irreversible process is obsolete and it is now evident that the development of liver fibrosis is a dynamic and potentially bidirectional process. Spontaneous resolution of scarring is seen in animal models of liver fibrosis and in human trials in which the stimuli responsible for chronic or repeated hepatic inflammation is successfully removed. Key players in the process are hepatic stellate cells, macrophages, MMPs and their inhibitors Timps. It is also evident that in advanced fibrotic liver disease, specific histological features define what is currently described as "irreversible" fibrosis. This includes the development of paucicellular scars enriched in extensively cross-linked matrix components, such as fibrillar collagen and elastin. Our recent work has focused on the role of macrophage metalloelastase (MMP-12) in the turnover of elastin in reversible and irreversible models of fibrosis. We have shown that elastin turnover in liver injury and fibrosis is regulated by macrophages via Mmp-12 expression, activity and ratio to its inhibitor Timp-1. Failure of elastin degradation, together with increased deposition leads to accumulation of elastin in the fibrotic scars.

2012-01-01

475

Characterizing Amosamine Biosynthesis in Amicetin Reveals AmiG as a Reversible Retaining Glycosyltransferase.  

PubMed

The antibacterial and antiviral agent amicetin is a disaccharide nucleoside antibiotic featuring a unique ?-(1?4)-glycoside bond between amosamine and amicetose, characteristic of a retaining glycosylation. In this study, two key steps for amosamine biosynthesis were investigated: the N-methyltransferase AmiH was demonstrated to be requisite for the dimethylation in amosamine, and the glycosyltransferase AmiG was shown to be necessary for amosaminylation. Biochemical and kinetic characterization of AmiG revealed for the first time the catalytic reversibility of a retaining glycosyltransferase involved in secondary metabolite biosynthesis. AmiG displayed substrate flexibility by utilizing five additional sugar nucleotides as surrogate donors. AmiG was also amenable to sugar and aglycon exchange reactions. This study indicates that AmiG is a potential catalyst for diversifying nucleoside antibiotics and paves the way for mechanistic studies of a natural-product retaining glycosyltransferase. PMID:23919735

Chen, Ruidong; Zhang, Haibo; Zhang, Gaiyun; Li, Sumei; Zhang, Guangtao; Zhu, Yiguang; Liu, Jinsong; Zhang, Changsheng

2013-08-09

476

Is reverse engineering always legal?  

Microsoft Academic Search

Reverse engineering-the process of looking at lower levels of abstraction to understand higher levels-is not limited to decompiling programs, as many believe. It is an excellent way to pinpoint what you need to build an interface or change a system to reflect new business goals. But unraveling someone's code opens up a legal can of worms, and as reverse engineering

C. Cifuentes; A. Fitzgerald

1999-01-01

477

Successive Reversals Involving Two Cues.  

National Technical Information Service (NTIS)

Rats were trained on a visual discrimination problem with two relevant cues--brightness and orientation. They were then given eight reversals in succession on the same problem. After reversals 7 and 8 they were tested with each cue presented on its own to...

N. S. Sutherland

1965-01-01

478

Preference Reversal in Multiattribute Choice  

ERIC Educational Resources Information Center

|A central puzzle for theories of choice is that people's preferences between options can be reversed by the presence of decoy options (that are not chosen) or by the presence of other irrelevant options added to the choice set. Three t