Showing papers on "Glucoside published in 2002"
TL;DR: It is proposed that different vacuolar transporters may be responsible for the sequestration of species-specific/endogenous and nonspecific/xenobiotic secondary compounds in planta.
Abstract: In many cases, secondary plant products accumulate in the large central vacuole of plant cells. However, the mechanisms involved in the transport of secondary compounds are only poorly understood. Here, we demonstrate that the transport mechanisms for the major barley ( Hordeum vulgare ) flavonoid saponarin (apigenin 6- C -glucosyl-7- O -glucoside) are different in various plant species: Uptake into barley vacuoles occurs via a proton antiport and is competitively inhibited by isovitexin (apigenin 6- C -glucoside), suggesting that both flavone glucosides are recognized by the same transporter. In contrast, the transport into vacuoles from Arabidopsis, which does not synthesize flavone glucosides, displays typical characteristics of ATP-binding cassette transporters. Transport of saponarin into vacuoles of both the species is saturable with a K m of 50 to 100 μm. Furthermore, the uptake of saponarin into vacuoles from a barley mutant exhibiting a strongly reduced flavone glucoside biosynthesis is drastically decreased when compared with the parent variety. Thus, the barley vacuolar flavone glucoside/H + antiporter could be modulated by the availability of the substrate. We propose that different vacuolar transporters may be responsible for the sequestration of species-specific/endogenous and nonspecific/xenobiotic secondary compounds in planta.
120 citations
TL;DR: Two new α-ionol derivatives are metabolites of (+)-( S )-abscisic acid and the 13 C-resonance of C-9 was found to be of particular diagnostic value in assigning the absolute configuration at that center in ionol glycosides.
115 citations
TL;DR: A marine fungal isolate, identified as Acremonium sp.
Abstract: A marine fungal isolate, identified as Acremonium sp., was mass cultivated and found to produce two novel hydroquinone derivatives, 7-isopropenylbicyclo[4.2.0]octa-1,3,5-triene-2,5-diol (1) and 7-isopropenylbicyclo[4.2.0]octa-1,3,5-triene-2,5-diol-5-beta-D-glucopyranoside (2). Compound 1 and its glucoside 2 possess a most unusual ring system. The new natural products (3R,4S)-3,4-dihydroxy-7-methyl-3,4-dihydro-1(2H)naphthalenone (3) and (3S,4S)-3,4-dihydroxy-7-methyl-3,4-dihydro-1(2H)-naphthalenone (4) were obtained as a 1:0.8 mixture. 2-(1-Methylethylidene)pentanedioic acid (5) was isolated for the first time as a natural product and its structure proven by X-ray analysis. In addition to these compounds an inseparable mixture of three new isomeric compounds, pentanedioic acid 2-(1-methylethylidene)-5-methyl ester (6), pentanedioic acid 2-(1-methylethylidene)-1-methyl ester (7), and pentanedioic acid 2-(1-methylethenyl)-5-methyl ester (8), was also obtained. Isolated together with the new compounds were three known hydroquinone derivatives, 9, 10, and 11. The structures of all compounds were determined by interpretation of their spectroscopic data (1D and 2D NMR, MS, UV, and IR). Each isolate was tested for its antioxidant properties, and compounds 1 and 9-11 were found to have significant activity.
93 citations
TL;DR: It is established that liquid chromatography-mass spectrometry affords a versatile high-sensitivity, high-fidelity technique for studies of the transport of complex organic molecules whose synthesis as radiolabeled derivatives is laborious and/or prohibitively expensive.
Abstract: Through the development and application of a liquid chromatography-mass spectrometry-based procedure for measuring the transport of complex organic molecules by vacuolar membrane vesicles in vitro, it is shown that the mechanism of uptake of sulfonylurea herbicides is determined by the ligand, glucose, or glutathione, to which the herbicide is conjugated. ATP-dependent accumulation of glucosylated chlorsulfuron by vacuolar membrane vesicles purified from red beet (Beta vulgaris) storage root approximates Michaelis-Menten kinetics and is strongly inhibited by agents that collapse or prevent the formation of a transmembrane H(+) gradient, but is completely insensitive to the phosphoryl transition state analog, vanadate. In contrast, ATP-dependent accumulation of the glutathione conjugate of a chlorsulfuron analog, chlorimuron-ethyl, is incompletely inhibited by agents that dissipate the transmembrane H(+) gradient but completely abolished by vanadate. In both cases, however, conjugation is essential for net uptake because neither of the unconjugated parent compounds are accumulated under energized or nonenergized conditions. That the attachment of glucose to two naturally occurring phenylpropanoids, p-hydroxycinnamic acid and p-hydroxybenzoic acid via aromatic hydroxyl groups, targets these compounds to the functional equivalent of the transporter responsible for chlorsulfuron-glucoside transport, confirms the general applicability of the H(+) gradient dependence of glucoside uptake. It is concluded that H(+) gradient-dependent, vanadate-insensitive glucoside uptake is mediated by an H(+) antiporter, whereas vanadate-sensitive glutathione conjugate uptake is mediated by an ATP-binding cassette transporter. In so doing, it is established that liquid chromatography-mass spectrometry affords a versatile high-sensitivity, high-fidelity technique for studies of the transport of complex organic molecules whose synthesis as radiolabeled derivatives is laborious and/or prohibitively expensive.
81 citations
TL;DR: In this paper, the alpha-arbutin, a useful cosmetic ingredient, was selectively synthesized by alpha-anomer-selective glucosylation of hydroquinone with maltose as the donor using lyophilized cells of Xanthomonas campestris WU-9701 as a biocatalyst.
72 citations
TL;DR: From the water-soluble portion of the methanol extract of dill, which has been used as a spice and medicine, thirty-three compounds, including a new monoterspenoid, six new monoterpenoid glycosides, a new aromatic compound glucoside and a new alkyl glucosides were obtained.
Abstract: From the water-soluble portion of the methanol extract of dill (fruit of Anethum graveolens L.), which has been used as a spice and medicine, thirty-three compounds, including a new monoterpenoid, six new monoterpenoid glycosides, a new aromatic compound glucoside and a new alkyl glucoside were obtained. Their structures were clarified by spectral investigation.
72 citations
Patent•
05 Sep 2002
TL;DR: A compound of formula (I), wherein A is CH2 or (CH2)2; R 1 is hydrogen, arylalkyl, alkenyl, or alkyl; R 2 is alkyls or perfluoroalkyl; and R?3 and R4? are as defined in this paper.
Abstract: A compound of formula (I), wherein A is CH2 or (CH2)2; R1 is hydrogen, arylalkyl, alkenyl, or alkyl; R2 is alkyl or perfluoroalkyl; and R?3 and R4? are as defined herein. Further provided are methods of using such compounds for the treatment of diabetes and related diseases, and to pharmaceutical compositions containing such compounds.
67 citations
TL;DR: Thirteen glycosidases of microbial origin and almond beta-glycosidase were assayed in octanol/DMF using a combination of hydrolysis, transglycosylation, and condensation reactions, in order to assess their potential for the production of alkyl glucosides.
Abstract: Thirteen glycosidases of microbial origin and almond beta-glycosidase were assayed in octanol/DMF (80:20, v/v), using a combination of hydrolysis, transglycosylation, and condensation reactions, in order to assess their potential for the production of alkyl glucosides. The two mesophile enzymes were highly impaired by the organic media. Three of the 11 thermophile enzymes gave interesting results in the hydrolysis and transglycosylation reactions, but they were highly inhibited by glucose. This made their use in a condensation reaction less interesting than the use of almond beta-glucosidase, which has a lower activity but shows less inhibition by the glucose.
66 citations
TL;DR: It is proposed that the aglycones of all five cyano glucosides are formed by the initial action of a cytochrome P450 enzyme of the CYP79 family convertingl-Leu into Z-3-methylbutanal oxime and subsequentaction of a less specific CYP71E enzyme converting the oxime into 3-methylbutyro nitrile and mediating subsequent hydroxylations at the α- and γ-, carbon atoms.
Abstract: Barley ( Hordeum vulgare ) seedlings contain five cyano glucosides derived from the amino acid l-leucine (Leu). The chemical structure and the relative abundance of the cyano glucosides were investigated by liquid chromatography-mass spectrometry and nuclear magnetic resonance analyses using spring barley cultivars with high, medium, and low cyanide potential. The barley cultivars showed a 10-fold difference in their cyano glucoside content, but the relative content of the individual cyano glucosides remained constant. Epiheterodendrin, the only cyanogenic glucoside present, comprised 12% to 18% of the total content of cyano glucosides. It is proposed that the aglycones of all five cyano glucosides are formed by the initial action of a cytochrome P450 enzyme of the CYP79 family convertingl-Leu into Z -3-methylbutanal oxime and subsequent action of a less specific CYP71E enzyme converting the oxime into 3-methylbutyro nitrile and mediating subsequent hydroxylations at the α-, as well as β- and γ-, carbon atoms. Presence of cyano glucosides in the barley seedlings was restricted to leaf tissue, with 99% confined to the epidermis cell layers of the leaf blade. Microsomal preparations from epidermal cells were not able to convertl-[ 14 C]Leu into the biosynthetic intermediate, Z -3-methylbutanal-oxime. This was only achieved using microsomal preparations from other cell types in the basal leaf segment, demonstrating translocation of the cyano glucosides to the epidermal cell layers after biosynthesis. A β-glucosidase able to degrade epiheterodendrin was detected exclusively in yet a third compartment, the endosperm of the germinating seed. Therefore, in barley, a putative function of cyano glucosides in plant defense is not linked to cyanide release.
65 citations
TL;DR: Five terpenes, three fatty acids, two sterols, and a monogalactosyldiacyl glycerol were isolated from the methylene chloride extract of the aerial part ofCirsium setidens and Compound3 exhibited significant cytotoxic activity against five human cancer cell lines.
Abstract: Five terpenes (1~5), three fatty acids (6~8), two sterols (9 and 11), and a monogalactosyldiacyl glycerol (10) were isolated from the methylene chloride extract of the aerial part ofCirsium setidens. Their chemical structures were determined to be α-tocopherol (1), 25-hydroper-oxycycloart-23-en-3p-ol (2), 24-hydroperoxycycloart-25-en-3(3-ol (3), mokko lactone (4), transphytol (5), 9, 12, 15-octadecatrienoic acid (6), 9, 12-octadecadienoic acid (7), hexadecanoic acid (8), acylglycosyl β-sitosterol (9), (2R)-1, 2-0-(9z, 12z, 15z-dioctadecatrienoyl)-3-0-β-D-galactopyranosyl glycerol (10) and p-sitosterol glucoside (11) by spectral evidences. Compound3 exhibited significant cytotoxic activity against five human cancer cell lines with its ED50 values ranging from 2.66 to 11.25 μ.M.
58 citations
TL;DR: In this article, the structure of (2R,3S)-Catechin-7-O-β-Dglucopyranoside was identified from barley and malt for the first time.
Abstract: (2R,3S)-Catechin-7-O-β-D-glucopyranoside is isolated from barley (Hordeum vulgare L.) and malt for the first time. For identification, the glucoside was isolated from acetone-water extracts of malt by polyamide clean-up and semi-preparative HPLC. The structure was elucidated by various NMR techniques, fast atom bombardment mass spectrometry and UV and circular dichroism spectroscopy. The investigation of 20 different barley varieties and the corresponding malts by HPLC with UV and coulometric electrode array detection revealed that the amount of the glucoside increases during malting. In contrast, the content of the monomeric (+)-catechin decreases and (–)-epicatechin was not detected.
TL;DR: 4-Hydroxycinnamoyl-CoA hydratase/lyase (HCHL), a crotonase homologue of phenylpropanoid catabolism from Pseudomonas fluorescens strain AN103, led to the formation of 4-hydroxybenzaldehyde metabolites when expressed in hairy root cultures of Datura stramonium L. established by transformation with Agrobacterium rhizogenes.
Abstract: 4-Hydroxycinnamoyl-CoA hydratase/lyase (HCHL), a crotonase homologue of phenylpropanoid catabolism from Pseudomonas fluorescens strain AN103, led to the formation of 4-hydroxybenzaldehyde metabolites when expressed in hairy root cultures of Datura stramonium L. established by transformation with Agrobacterium rhizogenes. The principal new compounds observed were the glucoside and glucose ester of 4-hydroxybenzoic acid, together with 4-hydroxybenzyl alcohol-O-β-D-glucoside. In lines actively expressing HCHL, these together amounted to around 0.5% of tissue fresh mass. No protocatechuic derivatives were found, although a trace of vanillic acid-β-D-glucoside was detected. There was no accumulation of 4-hydroxybenzaldehydes, whether free or in the form of their glucose conjugates. There was some evidence suggesting a diminished availability of feruloyl-CoA for the production of feruloyl putrescine and coniferyl alcohol. The findings are discussed in the context of a diversion of phenylpropanoid metabolism, and the ability of plants and plant cultures to conjugate phenolic compounds.
TL;DR: In this paper, the authors investigated the biotransformation of cinobufagin by cell suspension cultures of Catharanthus roseus and identified four new glucosylated derivatives.
TL;DR: The monocaffeoyl conjugate of prenylhydroquinone glucoside (3), the most potent inhibitor of leukotriene B(4) production (IC(50) = 33 microM), possesses a mixed hydroquinone-caffeoyL character that could be considered as a potential anti-inflammatory entity.
TL;DR: Passibiflorin, a bisglycoside containing the 6-deoxy-β- d -gulopyranosyl residue, was isolated from 19 species of Passiflora (Passifloraceae) as mentioned in this paper.
TL;DR: The polyphenol increasing effect of light/water stress was clearly observed in safflower compared to cucumber, suggesting that plants that are resistant to these stresses can accumulate substantial amounts of polyphenols compared to the plants which respond weakly to the stresses.
Abstract: To assess effects of the environmental stress on polyphenol compounds (polyphenols) in plants, the polyphenol contents were investigated in the seedlings of safflower (Carthamus tinctrius L.) and cucumber (Cucumis sativus L.) grown under three types of growth conditions: control; light stress, irradiated with strong light in the visible wavelength range; and light/water stress, irradiated with strong visible light with a limited water supply. The total polyphenol contents and the amounts of the major polyphenols, especially luteolin 7-O- glucoside in safflower cotyledons, and luteolin 7-O-glucoside and luteolin in safflower foliage leaves, increased in response to both stresses. The polyphenol increasing effect of light/water stress was clearly observed in safflower compared to cucumber, suggesting that plants that are resistant to these stresses can accumulate substantial amounts of polyphenols compared to the plants which respond weakly to the stresses.
TL;DR: The results indicate that expression of a tyrosine decarboxylase in potato does not channel tyramine into the hydroxycinnamoyl-CoA:tyramine N-(hydroxycinn amoyl)-transferase reaction but rather unexpectedly, into a different pathway leading to the formation of a potential storage compound.
TL;DR: Compounds 1 - 3 showed antioxidative activity in DPPH and cytochrome-c assay using HL-60 cell system and one- and two-dimensional NMR spectroscopy, including DEPT, NOESY, DQF-COSY, TOCSY, HMQC, and HMBC experiments.
TL;DR: The callus and, for the first time established, shoot cultures of Drosophyllum lusitanicum Link yielded new naphthalene glucoside-5-hydroxy-4-methoxy-2-naphthalenecarboxylic acid methyl ester and the pattern of phenolics found supports affinity of Dosophyllums to the families-Droseraceae, Ancistrocladaceae and Dioncophyllaceae.
TL;DR: The oxidation of arbutin by soluble and ionically bound to cell wall peroxidases from pear is described for the first time and the stoichiometry of the oxidized product formation versus hydrogen peroxide was nearly 2:1 suggesting that ar butin oxidation is a one-electron process.
TL;DR: From the water-soluble portion of the methanolic extract of caraway, an aromatic compound, an aroma compound glucoside and a glucide were isolated together with 16 known compounds, clarified as 2-methoxy-2-(4'-hydroxyphenyl)ethanol, junipediol A 2-O-beta-D-glucopyranoside and L-fucitol, respectively.
TL;DR: A new iridoid glucoside dimer and a non-glycosidic iridoids were isolated together with the known compounds from the leaves of Lasianthus wallichii, elucidated by spectroscopic and chemical evidence.
Abstract: A new iridoid glucoside dimer (1) and a non-glycosidic iridoid (2) was isolated together with the known compounds, asperuloside (3), paederoside (4), daphylloside (5), citroside A (6) and benzyl 6-O-α-L-rhamnopyranosyl-β-D-glucopyranoside (7), from the leaves of Lasianthus wallichii. The structures of the new compounds were elucidated by spectroscopic and chemical evidence.
Journal Article•
TL;DR: In this paper, the aerial parts of Phlomis lycia L. (Labiatae) were used for the first time to isolate a lignan glucoside and chlorogenic acid.
Abstract: From the aerial parts of Phlomis lycia L. (Labiatae) a lignan glucoside, (-)-dihydrodehyrodiconiferyl alcohol-9-O-b -D-glucopyranoside (1); a caffeic acid ester, chlorogenic acid (2); three phenylethanoid glycosides, forsythoside B (3), alyssonoside (4) and leucosceptoside B(5); and two iridoid glucosides, lamiide (6) andauroside (7), were isolated. The structure elucidation of the isolated compounds was carried out by spectroscopic (UV, IR, 1D- and 2D-NMR, FAB-MS) methods. (-)-Dihydrodehyrodiconiferyl alcohol-9-O-b -D-glucopyranoside (1) and chlorogenic acid (2) were isolated for the first time from Phlomis species in this study.
TL;DR: Cichoriin-6'-p-hydroxyphenyl acetate, a new natural product, was isolated from chicory leaves and described as a “new natural product”.
Journal Article•
TL;DR: Ten phenolic and flavonoid compounds including one new acylated flavonol glycoside were isolated from Psidium gauijava seeds and the structures of the new compound quercetin-3-O-beta-D-(2"-O-galloyl glucoside)-4'-O-vinylpropionate were elucidated.
Abstract: Ten phenolic and flavonoid compounds including one new acylated flavonol glycoside were isolated from Psidium gauijava seeds. The structures of the new compound quercetin-3-O-beta-D-(2"-O-galloyl glucoside)-4'-O-vinylpropionate and of the known compounds were elucidated by different chemical and physical methods, 1H- and 13C NMR spectral analysis.
TL;DR: Three compounds H-1, H-2 & CH-2 isolated from the chloroform extract of stem of Ipomoea turpethum and the crude petroleum ether, chloro form and ethyl acetate extracts were screened against thirteen pathogenic bacteria for their antibacterial activities.
Abstract: Three compounds H-1 (β-sitosteryl-β-D glucoside), H-2 (22, 23-dihydro-α-spinosteryl glucoside) & CH-2 (salicylic acid) isolated from the chloroform extract of stem of Ipomoea turpethum and the crude petroleum ether, chloroform and ethyl acetate extracts were screened against thirteen pathogenic bacteria for their antibacterial activities. The minimum inhibitory concentration (MIC) of the isolated compound CH-2 was also measured against Bacillus subtilis, Shigella dysenteriae, Sarcina lutea and Escherichia coli. The values were found to be between 128 and 256 µg/ml. The cytotoxic activity of CH-2 and chloroform and ethyl acetate extracts was also measured by brine shrimp lethality bioassay and the LC values were found 50 to be 56.23, 199.53 and 31.62 µg/ml, respectively.
TL;DR: A new iridoid glucoside, urphoside A, was isolated from Veronica hederifolia together with a known megastigmane glucosides, 3-hydroxy-5,6-epoxy-beta-ionol-9-O- beta-D-glucopyranoside, and a hexitol, dulcitol.
Abstract: A new iridoid glucoside, urphoside A, and six known iridoid glucosides, pikuroside, aucubin, veronicoside, catalposide, amphicoside, and verminoside, were isolated from Veronica hederifolia together with a known megastigmane glucoside, 3-hydroxy-5,6-epoxy-β-ionol-9-O-β-D-glucopyranoside, and a hexitol, dulcitol. The structures of the isolated compounds were established by the extensive 1D- and 2D-NMR spectroscopy.
TL;DR: In this article, a novel α-hydroxy acid derivative was synthesized by transesterification in non-aqueous phase using immobilized lipase as biocatalyst, and the results showed that conversion and initial rate decreased with the increase of water content.
Abstract: Ethyl glucoside lactate, a novel α-hydroxy acid derivative, was synthesized by transesterification in non-aqueous phase using immobilized lipase as biocatalyst. Parameters such as solvent type, substrate concentration, reaction temperature, and enzyme concentration were investigated to optimize the lipase-catalyzed transesterification. In solvent-free system with butyl lactate as both acyl donor and solvent, a 71% conversion was achieved. In order to investigate the effect of initial water content, the reactions were carried out in the mediums treated with molecular sieves. The results showed that conversion and initial rate decreased with the increase of water content. The conversion and initial rate reached to 95% and 67.4 mM/h, respectively, by carrying out the reaction under reduced pressure, which was employed to eliminate butanol and the initial water.
TL;DR: The successful scale-up of the enzymatic synthesis of α-methyl glucoside acrylate from laboratory-scale to pilot-scale was examined and a general method was developed to purify and recover the monoacrylate product from unreacted sugar and undesired diester by a simple crystallization and precipitation process.
Abstract: The successful scale-up of the enzymatic synthesis of alpha-methyl glucoside acrylate from laboratory-scale (milliliter) to pilot-scale (liter) was examined. Specifically, Candida antarctica lipase B (Novozym 435) was used as a biocatalyst to produce alpha-methyl glucoside acrylate via the transesterification of alpha-methyl glucoside (MG) with vinyl acrylate (VA) using acetone as a solvent. This is a pseudo-solid-phase synthesis; only a fraction of the alpha-methyl glucoside and the product are soluble in acetone. Molecular sieves were used to remove traces of water in the reaction medium and to increase enzyme stability by removing the acetaldehyde by-product. A general method was also developed to purify and recover the monoacrylate product from unreacted sugar and undesired diester by a simple crystallization and precipitation process.