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Glucoside
Kinds of Glucoside Selected AbstractsRole of Xanthurenic Acid 8- O -,- d -Glucoside, a Novel Fluorophore that Accumulates in the Brunescent Human Eye Lens,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2002Geetha Thiagarajan ABSTRACT We have been able to identify a blue fluorophore from the low-molecular weight soluble fraction of human adult nondiabetic brunescent cataract lenses as xanthurenic acid 8- O -,- d -glucoside (XA8OG) (excitation = 338 nm and emission = 440 nm). To determine the role of this fluorophore in the lens, we have examined its photophysical and photodynamic properties. We found XA8OG to have a fluorescence quantum yield (,) of 0.22 and a major emission lifetime of 12 ns. We found it to be a UVA-region sensitizer, capable of efficiently generating singlet oxygen species but little of superoxide. We also demonstrated that XA8OG oxidizes proteins when irradiated with UVA light, causing photodynamic covalent chemical damage to proteins. Its accumulation in the aging human lens (and the attendant decrease of its precursor O -,- d -glucoside of 3-hydroxykynurenine) can, thus, add to the oxidative burden on the system. XA8OG, thus, appears to be an endogenous chromophore in the lens, which can act as a cataractogenic agent. [source] Downstream Processing of Enzymatically Produced Geranyl GlucosideBIOTECHNOLOGY PROGRESS, Issue 5 2001B. Mattheus de Roode Geraniol plays an important role in the fragrance and flavor industry. The corresponding glucoside has interesting properties as a "slow release" aroma compound. Therefore, the enzymatic production and downstream processing of geranyl glucoside were investigated. Geranyl glucoside was produced in a spray column reactor with an initial production rate of 0.58 mg U,1 h,1. A pretreated hydrophobic microfiltration membrane was used to prevent migration of the aqueous, enzyme-containing phase to the downstream process. No retention of the glucoside, which accumulated in the geraniol phase, was found. On the basis of examples from the literature, four downstream processes were tested on their viability for this system. Extraction with water and foaming were not suitable to recover geranyl glucoside from geraniol. In the first case, the glucoside selectivity for the geraniol phase was found to be high, which made extraction with water unsuccessful. In the second case it was possible to obtain a stable foam, but significant enrichment of the foam with glucoside did not occur. Adsorption on alumina and distillation under reduced pressure were applied successfully and tested in-line with the bioreactor. A maximum glucoside adsorption of 7.86 mg g,1 was achieved on alumina. After desorption and evaporation of the extractant the pure glucoside was obtained quantitatively. A pure product could not be obtained after distillation because a small amount of glucose was present in the permeate as well, which accumulated in the bottom fraction. It was shown that with this reactor system a production of 1 kg of geranyl glucoside in 2 days is possible using an initial amount of 50,000 units of enzyme. [source] ChemInform Abstract: Biological Degradation of Taxol by Action of Cultured Cells on 7-Acetyltaxol-2,,-yl Glucoside.CHEMINFORM, Issue 29 2008Kei Shimoda Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] New Iridoid Glucoside from Picrorhiza kurroa Royle ex Benth.CHEMINFORM, Issue 36 2004Suparna Mandal Abstract For Abstract see ChemInform Abstract in Full Text. [source] A New Pentacyclic Triterpenoid Glucoside from Prunus serrulata var. spontanea.CHEMINFORM, Issue 31 2004Hyun Ah Jung No abstract is available for this article. [source] A New Monoterpene Glucoside from Portulaca oleraceaCHEMINFORM, Issue 10 2004Youngwan Seo Abstract For Abstract see ChemInform Abstract in Full Text. [source] Three New Benzophenone Glucosides from the Leaves of Planchonella obovataHELVETICA CHIMICA ACTA, Issue 3 2010Shoei-Sheng Lee Abstract Chemical investigation of the EtOH extract of the leaves of Planchonella obovata resulted in the isolation of four benzophenone glucosides, 1,4, of which three, 2,4, are new chemical entities together with five known flavonol glycosides. Their structures were elucidated by spectroscopic analysis. Among the isolated compounds, iriflophenone 2- O -(2,6-di- O -galloyl)- , - D -glucopyranoside (4) showed some activity (91.4 and 15.0% inhibition at 100 and 10,,g/ml, resp.) against the , -glucosidase of Bacillus stearothermophilus. [source] Three New Monoterpene Glucosides from Lamium amplexicauleHELVETICA CHIMICA ACTA, Issue 10 2009Masao Kikuchi Abstract Three new monoterpene glucosides, lamiuamplexosides A,C (1,3), along with thirteen known glucosides, were isolated from the whole plant of Lamium amplexicaule L. The structures of 1,3 were elucidated on the basis of spectroscopic, chemical, and physicochemical evidence. [source] New Acylated Secoiridoid Glucosides from Gentiana straminea (Gentianaceae)HELVETICA CHIMICA ACTA, Issue 2 2009Min Xu Abstract Two new acylated secoiridoid glucosides, 4,-acetyl-6,-{[2-hydroxy-3-(1- , - D -glucopyranosyloxy)]benzoyloxy}sweroside and 3,,4,-diacetyl-6,-{[2-hydroxy-3-(1- , - D -glucopyranosyloxy)]benzoyloxy}swertiamarin, named gentistraminosides A (1) and B (2), were isolated from the MeOH extract of Gentiana stramineaMaxim (Gentianaceae), together with twelve known ones, including eight iridoid and secoiridoid glucosides, macrophylloside A (3), loganic acid (4), secologanic acid (5), swertiamarin (6), gentiopicroside (7), loganic acid methyl ester (8), 6,- O - , - D -glucopyranosyl gentiopicroside (9), and loganic acid 11- O - , - D -glucopyranosyl ester (10), one flavone C -glucoside, isovitexin (11), one chromenecarboxylic acid glycosyl ester, macrophylloside D (12), and two triterpenoids, 1,,2,,3,,24-tetrahydroxyolean-12-en-28-oic acid (13), and 3,,6,,24-trihydroxyolean-12-en-28-oic acid (14). Their structures were determined by means of detailed spectroscopic (NMR and MS) analysis. [source] Iridoid Glucosides from Eremostachys moluccelloidesBungeHELVETICA CHIMICA ACTA, Issue 8 2007hsan Çal Abstract From the aerial parts of Eremostachys moluccelloidesBunge, a new iridoid glucoside, lamalbidic acid (7), was isolated as its choline salt 7a together with six known iridoid glucosides, 5-deoxysesamoside (1), 6, -hydroxy-7-epiloganin (2), lamalbide (3), shanzhiside methyl ester (4), sesamoside (5), and 5-deoxypulchelloside I (6). The structures of 7a and 7 (obtained from 7a) were elucidated by spectroscopic (UV, IR, 1D- and 2D-NMR, and ESI-MS) methods. [source] Stereoselective Conversion of Aucubin into Polyfunctionalized Tetrahydro-1H -cyclopenta[c]furan GlucosidesHELVETICA CHIMICA ACTA, Issue 1 2003Christine Mouriès Mitsunobu reaction of 2,,3,,4,,6,,10-penta- O -pivaloylaucubin (6) with phthalimide, triphenylphosphine, and diethyl azodicarboxylate gave (6R)-6-phthalimido-perpivaloylbartsioside (10) (Scheme,1). Selective oxidation reactions performed with perpivaloylaucubin (12) yielded (1R)- and (1S)-3(, - D -glucopyranosyloxy)-1H -cyclopenta[c]furan-1-carboxaldehydes 13 and 14 respectively (Scheme,2). Similarly, perpivaloyl-6-epiaucubin (9) and 10 afforded the corresponding (1S)-carboxaldehyde 15 and (1R)-carboxaldehyde 16, respectively. The protected cyclopentafuran glycosides obtained in this way are versatile synthons, which may prove useful for further chemical diversification. [source] Evaluation of novel fluorogenic substrates for the detection of glycosidases in Escherichia coli and enterococciJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2006J.D. Perry Abstract Aims:, Enzyme substrates based on 4-methylumbelliferone are widely used for the detection of Escherichia coli and enterococci in water, by detection of , -glucuronidase and , -glucosidase activity respectively. This study aimed to synthesize and evaluate novel umbelliferone-based substrates with improved sensitivity for these two enzymes. Methods and Results:, A novel , -glucuronide derivative based on 6-chloro-4-methylumbelliferone (CMUG) was synthesized and compared with 4-methylumbelliferyl- , - d -glucuronide (MUG) using 42 strains of E. coli in a modified membrane lauryl sulfate broth. Over 7 h of incubation, the fluorescence generated from the hydrolysis of CMUG by E. coli was over twice that from MUG, and all of the 38 glucuronidase-positive strains generated a higher fluorescence with CMUG compared with MUG. Neither substrate caused inhibition of bacterial growth in any of the tested strains. Four , -glucosidase substrates were also synthesized and evaluated in comparison with 4-methylumbelliferyl- , - d -glucoside (MU-GLU) using 42 strains of enterococci in glucose azide broth. The four substrates comprised , -glucoside derivatives of umbelliferone-3-carboxylic acid and its methyl, ethyl and benzyl esters. Glucosides of the methyl, ethyl and benzyl esters of umbelliferone-3-carboxylic acid, were found to be superior to MU-GLU for the detection of enterococci, especially after 18 h of incubation, while umbelliferone-3-carboxylic acid- , - d -glucoside was inferior. However, the variability in detectable , -glucosidase activity among the different strains of enterococci in short-term assays using the three carboxylate esters (7 h incubation) may compromise their use for rapid detection and enumeration of these faecal indicator bacteria. Conclusions:, The , -glucuronidase substrate CMUG appears to be a more promising detection system than the various , -glucosidase substrates tested. Significance and Impact of the Study:, The novel substrate CMUG showed enhanced sensitivity for the detection of , -glucuronidase-producing bacteria such as E. coli, with a clear potential for application in rapid assays for the detection of this indicator organism in natural water and other environmental samples. [source] Recovery of Limonoid Glucosides from Citrus MolassesJOURNAL OF FOOD SCIENCE, Issue 8 2002T.K. Schoch ABSTRACT: A method to recover multi-gram quantities of limonoid glucosides from citrus molasses using ion-exchange and styrene/divinylbenzene resins has been developed. A cation exchange resin is used to decolorize the molasses, while an anion exchanger is used to separate limonoid glucosides from other negatively charged compounds. Styrene/divinylbenzene resins are used to bind limonoid glucosides and remove water-soluble materials. The method affords approximately 5 grams of a water-soluble powder containing over 60% by weight limonoid glucosides per liter of molasses. An analysis of the efficiency of the method shows that less than 10% of the total limonoid glucosides are lost during recovery. [source] Effects of Naturally Occurring Stilbene Glucosides from Medicinal Plants and Wine, on Tumour Growth and Lung Metastasis in Lewis Lung Carcinoma-Bearing MiceJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2000YOSHIYUKI KIMURA Stilbene glucosides are naturally occurring phytoalexins, found in a variety of medicinal plants. Among the stilbene derivatives, resveratrol 3- O -D-glucoside (piceid) is found in grapes and wine. We studied the effects of stilbene glucosides isolated from medicinal plants and grapes on tumour growth and lung metastasis in mice bearing highly metastastic Lewis lung carcinoma (LLC) tumours. We also studied the inhibitory effects of stilbene glucosides on differentiation of human umbilical vein endothelial cells (HUVECs) to form a capillary network. Tumour growth in the right hind paw and lung metastasis were inhibited by oral administration of the stilbene glucosides, piceid and 2,3,5,4,-tetrahydroxystilbene-2- O -D-glucoside for 33 consecutive days, in LLC-bearing mice. As the number of CD8+ and NK1.1+ T cells in the spleen was not affected, the inhibitory effects of these stilbene glucosides on tumour growth and lung metastasis could not be explained by natural killer or cytotoxic T lymphocyte activation. Piceid inhibited the DNA synthesis in LLC cells at a concentration of 1000 ,m, but not at lower concentrations (10,100 ,M). 2,3,5,4,-Tetra-hydroxystilbene-2- O -D-glucoside also inhibited DNA synthesis in LLC cells (IC50 81 ,M). In addition, both stilbene glucosides inhibited the formation of capillary-like tube networks (angiogenesis) of HUVECs at concentrations of 100 to 1000 ,M. We suggest that the antitumour and antimetastatic activity of the stilbene glucosides, piceid and 2,3,5,4,-tetrahydroxystilbene-2- O -D-glucoside, might be due to the inhibition of DNA synthesis in LLC cells and angiogenesis of HUVECs. [source] Purification of citrus limonoids and their differential inhibitory effects on human cytochrome P450 enzymesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2007Shibu M Poulose Abstract Recent studies demonstrated that citrus limonoids and flavonoids possess numerous health promoting properties. In the present study, glucosides of limonoids and flavonoids were purified from citrus molasses and limonoid aglycones from citrus seeds. Glucosides were separated on styrene (divinylbenzene), Q-sepharose resins with increasing concentration of sodium chloride. A pH-dependent cold precipitation was carried out for the isolation of naringin in large quantity. Major aglycones such as limonin and nomilin were isolated from seeds by direct crystallization and minor limonoids were purified by vacuum liquid chromatography. The structures of the isolated compounds were confirmed by NMR spectra. Individual limonoids were tested for O -dealkylase and hydroxylase activities of human cytochrome P450 (CYP) isoenzymes such as CYP1A2, CYP1B1, CYP3A4 and CYP19, using ethoxyresorufin, methoxyresorufin and dibenzylfluorescein as substrates. Partial to high inhibition of CYPs was observed in dose-dependent assays. Significant (P < 0.001) reductions in enzyme activities were observed with purified compounds above 2 µmol. Kinetic analyses indicated that limonin glucoside inhibited CYP19 competitively (IC50, 7.1 µ mol L,1), whereas Nomilinic acid glucoside inhibited it noncompetitively (IC50, 9.4 µ mol,1). Nomilinic acid glucoside was the most potent limonoid, with an overall IC50 of < 10 µ mol, for all the enzymes tested. The differential inhibition of CYPs can be ascribed to structural variations of the limonoid nucleus. Limonoid inhibition of key CYPs involved in carcinogenesis supports growing evidence that citrus limonoids act as anticancer agents. Copyright © 2007 Society of Chemical Industry [source] Total Synthesis of Two Naturally Occurring Polyacetylenic Glucosides (-)-Bidensyneoside A1 (Ia) and B (Ib), and an Analogue (Ic) of (-)-Bidensyneoside C (Id).CHEMINFORM, Issue 24 2006Benjamin W. Gung Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] New Megastigmane Glucosides from Excoecaria cochinchinensis Lour. var. cochinchinensis.CHEMINFORM, Issue 19 2006Phan Minh Giang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Camptothecins and Two New Monoterpene Glucosides from Ophiorrhiza liukiuensis.CHEMINFORM, Issue 12 2006Mariko Kitajima Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis of ,-Unsaturated O-Protected Glucosides as Precursors for Unsaturated Neutral Bolaforms.CHEMINFORM, Issue 24 2003S. Konstantinovic Abstract For Abstract see ChemInform Abstract in Full Text. [source] A New Flavone Xyloside and Two New Flavan-3-ol Glucosides from Juniperus communis var. depressaCHEMISTRY & BIODIVERSITY, Issue 1 2007Naoki Iida Abstract A new flavone xyloside, 1, and two new flavan-3-ol glucosides, 3 and 4, were isolated together with three known flavones, 2, 11, and 12, five known flavans, 5,9, and a known dihydrochalcone, 10, from the stems and leaves of Juniperus communis var. depressa (Cupressaceae) collected in Oregon, U.S.A., and their structures were determined on the basis of spectral evidence. A novel flavone nucleus such as that in 1 is seldom found in nature today, and new methylcatechin glucosides 3 and 4 are also rare in nature. In addition, we investigated the inhibitory activity of individual components, i.e., 8,11, and others, that were abundantly isolated from the same plant material for the Maillard reaction. [source] Metabolic engineering of Saccharomyces cerevisiae for the synthesis of the wine-related antioxidant resveratrolFEMS YEAST RESEARCH, Issue 1 2003John V.W. Becker Abstract The stilbene resveratrol is a stress metabolite produced by Vitis vinifera grapevines during fungal infection, wounding or UV radiation. Resveratrol is synthesised particularly in the skins of grape berries and only trace amounts are present in the fruit flesh. Red wine contains a much higher resveratrol concentration than white wine, due to skin contact during fermentation. Apart from its antifungal characteristics, resveratrol has also been shown to have cancer chemopreventive activity and to reduce the risk of coronary heart disease. It acts as an antioxidant and anti-mutagen and has the ability to induce specific enzymes that metabolise carcinogenic substances. The objective of this pilot study was to investigate the feasibility of developing wine yeasts with the ability to produce resveratrol during fermentation in both red and white wines, thereby increasing the wholesomeness of the product. To achieve this goal, the phenylpropanoid pathway in Saccharomyces cerevisiae would have to be introduced to produce p -coumaroyl-CoA, one of the substrates required for resveratrol synthesis. The other substrate for resveratrol synthase, malonyl-CoA, is already found in yeast and is involved in de novo fatty-acid biosynthesis. We hypothesised that production of p -coumaroyl-CoA and resveratrol can be achieved by co-expressing the coenzyme-A ligase-encoding gene (4CL216) from a hybrid poplar and the grapevine resveratrol synthase gene (vst1) in laboratory strains of S. cerevisiae. This yeast has the ability to metabolise p -coumaric acid, a substance already present in grape must. This compound was therefore added to the synthetic media used for the growth of laboratory cultures. Transformants expressing both the 4CL216 and vst1 genes were obtained and tested for production of resveratrol. Following ,-glucosidase treatment of organic extracts for removal of glucose moieties that are typically bound to resveratrol, the results showed that the yeast transformants had produced the resveratrol ,-glucoside, piceid. This is the first report of the reconstruction of a biochemical pathway in a heterologous host to produce resveratrol. [source] The effect of exogenous pectinase on DMHF and derivatives in clarified strawberry juice (Fragaria × ananassa, cv. Elsanta)FLAVOUR AND FRAGRANCE JOURNAL, Issue 5 2002Emanuela Mura Abstract The effect of exogenous pectinase on the levels of 2,5-dimethyl-4-hydroxy-2H -furan-one (DMHF) and DMHF-glucoside was studied in clarified strawberry juice (Fragaria × ananassa, cv. Elsanta). The extent of conversion of DMHF-malonyl glucoside to DMHF-glucoside and DMHF was monitored at three different temperatures (45 °C, 50 °C and 60 °C) and at three different pH values (pH 3.0, 4.0 and 5.4). The effect of using two different concentrations of pectinase was also studied. Based on these results, the endogenous levels of DMHF-malonyl glucoside were calculated for the first time in strawberries. Copyright © 2002 John Wiley & Sons, Ltd. [source] New Acylated Secoiridoid Glucosides from Gentiana straminea (Gentianaceae)HELVETICA CHIMICA ACTA, Issue 2 2009Min Xu Abstract Two new acylated secoiridoid glucosides, 4,-acetyl-6,-{[2-hydroxy-3-(1- , - D -glucopyranosyloxy)]benzoyloxy}sweroside and 3,,4,-diacetyl-6,-{[2-hydroxy-3-(1- , - D -glucopyranosyloxy)]benzoyloxy}swertiamarin, named gentistraminosides A (1) and B (2), were isolated from the MeOH extract of Gentiana stramineaMaxim (Gentianaceae), together with twelve known ones, including eight iridoid and secoiridoid glucosides, macrophylloside A (3), loganic acid (4), secologanic acid (5), swertiamarin (6), gentiopicroside (7), loganic acid methyl ester (8), 6,- O - , - D -glucopyranosyl gentiopicroside (9), and loganic acid 11- O - , - D -glucopyranosyl ester (10), one flavone C -glucoside, isovitexin (11), one chromenecarboxylic acid glycosyl ester, macrophylloside D (12), and two triterpenoids, 1,,2,,3,,24-tetrahydroxyolean-12-en-28-oic acid (13), and 3,,6,,24-trihydroxyolean-12-en-28-oic acid (14). Their structures were determined by means of detailed spectroscopic (NMR and MS) analysis. [source] Iridoid Glucosides from Eremostachys moluccelloidesBungeHELVETICA CHIMICA ACTA, Issue 8 2007hsan Çal Abstract From the aerial parts of Eremostachys moluccelloidesBunge, a new iridoid glucoside, lamalbidic acid (7), was isolated as its choline salt 7a together with six known iridoid glucosides, 5-deoxysesamoside (1), 6, -hydroxy-7-epiloganin (2), lamalbide (3), shanzhiside methyl ester (4), sesamoside (5), and 5-deoxypulchelloside I (6). The structures of 7a and 7 (obtained from 7a) were elucidated by spectroscopic (UV, IR, 1D- and 2D-NMR, and ESI-MS) methods. [source] The effects of carbohydrates upon the survival and reproduction of adult female Pimpla turionellae L. (Hym., Ichneumonidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 4 2001Özalp In this study the effects of 23 carbohydrates belonging to various groups upon the survival egg production and egg of female adult Pimpla turionellae L. were investigated. The best results among the carbohydrates tested was obtained with sucrose which was also employed as control. Glucose, maltose, trehalose and melezitose on the other hand showed no significant effect. The egg production was observed to be unaffected by glucose and maltose although it showed significant increase with trehalose and significant decrease with melezitose. Fructose and sorbitol caused a significant decrease in the survival of the insect. Fructose and sorbitol did not have any significant effect upon egg production whereas galactose caused a significant decrease. With the exception of galactose, no carbohydrate caused any significant effect upon egg hatching. Although they did not produce any eggs the female insects survived for 13.17, 15.13, 11.58 and 15.83 days in mannose, melibiose, raffinose and mannitol, respectively. The shortest life span was observed in arabinose followed by ,-methyl- D -glucoside, dulcitol, rhamnose, cellobiose, xylose, starch, lactose, sarbose, ribose and glycogen. [source] Antibacterial activity of plant extracts from northwestern ArgentinaJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007J.R. Soberón Abstract Aims:, To determine the antibacterial and cytotoxic activities of aqueous and ethanolic extracts of northwestern Argentinian plants used in folk medicine. To compare the mentioned activities with those of five commercial antibiotics. To identify the compounds responsible for the antibacterial activity. Methods and Results:, Plant extracts were prepared according to traditional uses in northwestern Argentina. Antibacterial activity was assayed by agar dilution in Petri dishes and broth dilution in 96-well plates. Lethal dose 50 (LD50) was determined by the Artemia salina assay. Phytochemical analysis was performed by sample adsorption on silica gel, thin-layer chromatography (TLC), bioautography and UV-visible spectra. The results showed that Tripodanthus acutifolius aqueous extracts have lower minimal inhibitory concentrations (MIC) (502 and 506 ,g of extracted material (EM) per ml for infusion and decoction, respectively) than cefotaxim MIC (640 ,g ml,1) against Acinetobacterfreundii (303). These data were lower than their LD50. Tripodanthus acutifolius tincture showed lower MIC (110 ,g of EM per ml) and minimal bactericidal concentration (MBC) (220 ,g of EM per ml) than cefotaxim (MIC and MBC of 320 ,g ml,1) for Pseudomonasaeruginosa. This extract also showed a MIC/MBC of 110/220 ,g of EM per ml, lower than oxacillin (MIC/MBC of 160/220 ,g ml,1) for Staphylococcus aureus (ATCC 25923). The cytotoxicity of all extracts were compared with that of commercial antibiotics. Rutin (3,3,,4,,5,7-pentahydroxyflavone 3- , -rhamnosilglucoside), iso -quercitrin (3,3,,4,,5,7-pentahydroxyflavone 3- , -glucoside) and a terpene would be partially responsible for the antibacterial activity of T. acutifolius infusion. Conclusions:,Tripodanthus acutifolius extracts had the ability to inhibit bacterial growth. The antibacterial activity differs with the applied extractive method, and it could be partially attributed to glycoflavonoids. This paper contributes to the knowledge of antibacterial capacity of plants from northwestern Argentina. Significance and Impact of the Study:, These antibacterial activities support further studies to discover new chemical structures that can contribute to alleviate or cure some illnesses. [source] Evaluation of novel fluorogenic substrates for the detection of glycosidases in Escherichia coli and enterococciJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2006J.D. Perry Abstract Aims:, Enzyme substrates based on 4-methylumbelliferone are widely used for the detection of Escherichia coli and enterococci in water, by detection of , -glucuronidase and , -glucosidase activity respectively. This study aimed to synthesize and evaluate novel umbelliferone-based substrates with improved sensitivity for these two enzymes. Methods and Results:, A novel , -glucuronide derivative based on 6-chloro-4-methylumbelliferone (CMUG) was synthesized and compared with 4-methylumbelliferyl- , - d -glucuronide (MUG) using 42 strains of E. coli in a modified membrane lauryl sulfate broth. Over 7 h of incubation, the fluorescence generated from the hydrolysis of CMUG by E. coli was over twice that from MUG, and all of the 38 glucuronidase-positive strains generated a higher fluorescence with CMUG compared with MUG. Neither substrate caused inhibition of bacterial growth in any of the tested strains. Four , -glucosidase substrates were also synthesized and evaluated in comparison with 4-methylumbelliferyl- , - d -glucoside (MU-GLU) using 42 strains of enterococci in glucose azide broth. The four substrates comprised , -glucoside derivatives of umbelliferone-3-carboxylic acid and its methyl, ethyl and benzyl esters. Glucosides of the methyl, ethyl and benzyl esters of umbelliferone-3-carboxylic acid, were found to be superior to MU-GLU for the detection of enterococci, especially after 18 h of incubation, while umbelliferone-3-carboxylic acid- , - d -glucoside was inferior. However, the variability in detectable , -glucosidase activity among the different strains of enterococci in short-term assays using the three carboxylate esters (7 h incubation) may compromise their use for rapid detection and enumeration of these faecal indicator bacteria. Conclusions:, The , -glucuronidase substrate CMUG appears to be a more promising detection system than the various , -glucosidase substrates tested. Significance and Impact of the Study:, The novel substrate CMUG showed enhanced sensitivity for the detection of , -glucuronidase-producing bacteria such as E. coli, with a clear potential for application in rapid assays for the detection of this indicator organism in natural water and other environmental samples. [source] Effect of silybin and its glycosides on the expression of cytochromes P450 1A2 and 3A4 in primary cultures of human hepatocytesJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 3 2005Pavel Kosina Abstract Four ,-glycosides of flavonoligan silybin, i.e. silybin ,-galactoside, silybin ,-glucoside, silybin ,-maltoside, silybin ,-lactoside were synthesized in order to improve silybin water solubility and bioavailability (K,en et al., J Chem Soc, Perkin Trans 1, 2467,2474, 1997). The presented paper deals with the effect of silybin and its synthetic ,-glycosides on the expression of two major cytochrome P450 isoforms, CYP1A2 and CYP3A4. Primary cultures of human hepatocytes were the model of choice. mRNAs were analyzed using Northern blot and P-radiolabelled probes. CYP protein content was determined by immunoblotting using specific antibodies. Silybin and its ,-glycosides do not induce expression of CYP1A2 and CYP3A4. Tested compounds did not affect inducible expression of CYP1A2 and CYP3A4 by dioxin and rifampicin, respectively, as evaluated at the level of mRNAs and proteins. Silybin and its ,-glycosides do not interfere with the expression of CYP1A2 and CYP3A4, are not likely to produce drug,drug interactions in terms of the inducibility of two important cytochromes P450. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:149,153, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20066 [source] A systematic review of wound cleansing for pressure ulcersJOURNAL OF CLINICAL NURSING, Issue 15 2008FFNMRCSI, Zena Moore MSc Aim., The aim of this study was to use a Cochrane systematic review process to explore the effect of wound cleansing solutions and techniques on pressure ulcer healing. Background., Pressure ulcers impose a significant financial burden on health care systems and negatively affect the quality of life. Wound cleansing is an important component of pressure ulcer care; however, there is uncertainty regarding best practice. Design., Systematic review. Methods., The Specialised Trials Register of the Cochrane Wounds Group, the Cochrane Central Register of Controlled Trials and bibliographies of relevant publications were searched. Drug companies and experts in the field were also contacted. Randomized controlled trials (RCTs) comparing wound cleansing with no wound cleansing, or different wound cleansing solutions, or different cleansing techniques, were eligible for inclusion. For dichotomous outcomes, relative risk (RR) plus 95% confidence intervals (CI) were calculated; for continuous outcomes, weighted mean difference plus 95% CI were calculated. Meta analysis was not conducted because of the small number of diverse RCTs identified. Results., No studies compared cleansing with no cleansing. A statistically significant improvement in healing occurred for wounds cleansed with saline spray containing Aloe vera, silver chloride and decyl glucoside (Vulnopur) compared with isotonic saline (p = 0·025). No statistically significant change in healing was seen when water was compared with saline (RR 3·00, 95% CI 0·21, 41·89). No statistically significant change in healing was seen for ulcers cleansed with, or without, a whirlpool (RR 2·10, 95% CI 0·93,4·76). Conclusion., There is little trial evidence to support the use of any particular wound cleansing solution or technique for pressure ulcers. Relevance to clinical practice., No firm recommendations for ways of cleansing pressure ulcers in clinical practice can be made, the lack of RCT evidence should be a concern for health care providers. [source] ANTHOCYANIN INTERACTIONS WITH DNA: INTERCALATION, TOPOISOMERASE I INHIBITION AND OXIDATIVE REACTIONSJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2008MICHAEL R. WEBB ABSTRACT Anthocyanins and their aglycone anthocyanidins are pigmented flavonoids found in significant amounts in many commonly consumed foods. They exhibit a complex chemistry in aqueous solution, which makes it difficult to study their chemistry under physiologic conditions. Here we used a gel electrophoresis assay employing supercoiled DNA plasmid to examine the ability of these compounds (1) to intercalate DNA; (2) to inhibit human topoisomerase I through both inhibition of plasmid relaxation activity (catalytic inhibition) and stabilization of the cleavable DNA,topoisomerase complex (poisoning); and (3) to inhibit or enhance oxidative single-strand DNA nicking. We found no evidence of DNA intercalation by anthocyan(id)ins in the physiologic pH range for any of the compounds used in this study , cyanidin chloride, cyanidin 3- O -glucoside, cyanidin 3,5- O -diglucoside, malvidin 3- O -glucoside and luteolinidin chloride. The anthocyanins inhibited topoisomerase relaxation activity only at high concentrations (>50 µM), and we could find no evidence of topoisomerase I cleavable complex stabilization by these compounds. However, we observed that all of the anthocyan(id)ins used in this study were capable of inducing significant oxidative DNA strand cleavage (nicking) in the presence of 1 mM dithiothreitol, while the free radical scavenger, dimethyl sulfoxide (DMSO), at concentrations typically used in similar studies, completely inhibited DNA nicking. Finally, we proposed a mechanism to explain the anthocyan(id)in-induced oxidative DNA cleavage observed under our experimental conditions. PRACTICAL APPLICATIONS This study provided improved understanding of the mechanisms by which anthocyan(id)ins interact with DNA. By characterizing the chemistry and solution properties of these important dietary components, we obtained improved information on how the anthocyan(id)ins might function in living systems. 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