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Weihua Xiao - One of the best experts on this subject based on the ideXlab platform.
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isolation and purification of flavonoid glucosides from radix astragali by high speed counter current chromatography
Journal of Chromatography B, 2009Co-Authors: Weihua XiaoAbstract:Abstract High-speed counter-current chromatography methods, combined with resin chromatography were applied to the separation and purification of flavonoid Glycosides from the Chinese medicinal herb, Radix Astragali. Five flavonoid Glycosides, namely calycosin-7-O-β- d -glucoside, ononin, (6aR, 11aR)-9,10-dimethoxypterocarpan-3-O-β- d -glucoside, (3R)-2′-hydroxy-3′,4′-dimethoxyisoflavan-7-O-β- d -glucoside and calycosin-7-O-β- d -glucoside-6′′-O-acetate, were obtained. Among them, calycosin-7-O-β- d -glucoside-6′′-O-acetate was preparatively separated from Radix Astragali for the first time. Their structures were identified by ESI–MS, 1H NMR, 13C NMR, and 2D NMR.
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Isolation and purification of flavonoid glucosides from Radix Astragali by high-speed counter-current chromatography.
Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2009Co-Authors: Weihua XiaoAbstract:High-speed counter-current chromatography methods, combined with resin chromatography were applied to the separation and purification of flavonoid Glycosides from the Chinese medicinal herb, Radix Astragali. Five flavonoid Glycosides, namely calycosin-7-O-beta-d-glucoside, ononin, (6aR, 11aR)-9,10-dimethoxypterocarpan-3-O-beta-d-glucoside, (3R)-2'-hydroxy-3',4'-dimethoxyisoflavan-7-O-beta-d-glucoside and calycosin-7-O-beta-d-glucoside-6''-O-acetate, were obtained. Among them, calycosin-7-O-beta-d-glucoside-6''-O-acetate was preparatively separated from Radix Astragali for the first time. Their structures were identified by ESI-MS, (1)H NMR, (13)C NMR, and 2D NMR.
Peter C. H. Hollman - One of the best experts on this subject based on the ideXlab platform.
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the type of sugar moiety is a major determinant of the small intestinal uptake and subsequent biliary excretion of dietary quercetin Glycosides
British Journal of Nutrition, 2004Co-Authors: Ilja C W Arts, Aloys L A Sesink, Maria Faassenpeters, Peter C. H. HollmanAbstract:Quercetin is an important dietary flavonoid with putative beneficial effects in the prevention of cancer and CVD. The in vivo bioactivity of quercetin depends on its bioavailability, which varies widely between foods. We used an in situ rat intestinal perfusion model to study whether differential small intestinal hydrolysis of the sugar moiety of five naturally occurring quercetin Glycosides determines the small intestinal uptake and subsequent biliary excretion of quercetin. After 30 min perfusion, a decrease of intact quercetin Glycoside in perfusate was observed for quercetin-3-O-s-glucoside (20·9 (SEM 1·4) mmol/l) and quercetin-4 0 -O-s-glucoside (23·5 (SEM 1·6) mmol/ l), but not of quercetin-3-O-s-galactoside, quercetin-3-O-s-rhamnoside and quercetin-3-O-a-arabinopyranoside. Appearance of free quercetin in perfusate and conjugated quercetin metabolites (quercetin, isorhamnetin, and tamarixetin) in portal and peripheral plasma and bile were also significantly greater after treatment with quercetin-3-O-s-glucoside or quercetin-4 0 -O-s-glucoside compared with any of the other Glycosides. Thus, the type of sugar moiety is a major determinant of the small intestinal absorption of quercetin Glycosides, but the position (3 or 4 0 ) of the glucose moiety does not further influence absorption. The poor bioavailability of important dietary quercetin Glycosides has implications for their in vivo bioactivities. Flavonoid: Quercetin Glycoside: Intestinal absorption: Lactase phlorizin hydrolase: Bile
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Bioavailabilities of quercetin-3-glucoside and quercetin-4'-glucoside do not differ in humans.
The Journal of nutrition, 2000Co-Authors: Margreet R Olthof, Peter C. H. Hollman, Tom B. Vree, Martijn B. KatanAbstract:The flavonoid quercetin is an antioxidant which occurs in foods mainly as Glycosides. The sugar moiety in quercetin Glycosides affects their bioavailability in humans. Quercetin-3-rutinoside is an important form of quercetin in foods, but its bioavailability in humans is only 20% of that of quercetin-4'-glucoside. Quercetin-3-rutinoside can be transformed into quercetin-3-glucoside by splitting off a rhamnose molecule. We studied whether this 3-glucoside has the same high bioavailability as the quercetin-4'-glucoside. To that end we fed five healthy men and four healthy women (19-57 y) a single dose of 325 micromol of pure quercetin-3-glucoside and a single dose of 331 micromol of pure quercetin-4'-glucoside and followed the plasma quercetin concentrations. The bioavailability was the same for both quercetin glucosides. The mean peak plasma concentration of quercetin was 5.0+/-1.0 micromol/L (+/-SE) after subjects had ingested quercetin-3-glucoside and 4.5+/-0.7 micromol/L after quercetin-4'-glucoside consumption. Peak concentration was reached 37 +/-12 min after ingestion of quercetin-3-glucoside and 27+/-5 min after quercetin-4'-glucoside. Half-life of elimination of quercetin from blood was 18.5+/-0.8 h after ingestion of quercetin-3-glucoside and 17.7+/-0.9 h after quercetin-4'-glucoside. We conclude that quercetin glucosides are rapidly absorbed in humans, irrespective of the position of the glucose moiety. Conversion of quercetin Glycosides into glucosides is a promising strategy to enhance bioavailability of quercetin from foods.
Soren Rosendal Jensen - One of the best experts on this subject based on the ideXlab platform.
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iridoid and phenylethanoid Glycosides in the new zealand sun hebes veronica plantaginaceae
Phytochemistry, 2012Co-Authors: Rilka M Taskova, Tetsuo Kokubun, P J Garnockjones, Soren Rosendal JensenAbstract:The sun hebes are a small clade of New Zealand Veronica formerly classified as Heliohebe. The water-soluble compounds of Veronica pentasepala, Veronica raoulii and Veronica hulkeana were studied and 30 compounds including 15 iridoid glucosides, 12 phenylethanoid Glycosides, the acetophenone glucoside pungenin, the mannitol ester hebitol II and mannitol were isolated. Of these, five were previously unknown in the literature: dihydroverminoside and 3,3′,4,4′-tetrahydroxy-α-truxillic acid 6-O-catalpyl diester, named heliosepaloside, as well as three phenylethanoid Glycoside esters heliosides D, E and F, all derivatives of aragoside. The esters of cinnamic acid derivatives with iridoid and phenylethanoid Glycosides and an unusually high concentration of verminoside were found to be the most distinctive chemotaxonomic characters of the sun hebes. The chemical profiles of the species were compared and used to assess the phylogenetic relationships in the group.
Rilka M Taskova - One of the best experts on this subject based on the ideXlab platform.
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iridoid and phenylethanoid Glycosides in the new zealand sun hebes veronica plantaginaceae
Phytochemistry, 2012Co-Authors: Rilka M Taskova, Tetsuo Kokubun, P J Garnockjones, Soren Rosendal JensenAbstract:The sun hebes are a small clade of New Zealand Veronica formerly classified as Heliohebe. The water-soluble compounds of Veronica pentasepala, Veronica raoulii and Veronica hulkeana were studied and 30 compounds including 15 iridoid glucosides, 12 phenylethanoid Glycosides, the acetophenone glucoside pungenin, the mannitol ester hebitol II and mannitol were isolated. Of these, five were previously unknown in the literature: dihydroverminoside and 3,3′,4,4′-tetrahydroxy-α-truxillic acid 6-O-catalpyl diester, named heliosepaloside, as well as three phenylethanoid Glycoside esters heliosides D, E and F, all derivatives of aragoside. The esters of cinnamic acid derivatives with iridoid and phenylethanoid Glycosides and an unusually high concentration of verminoside were found to be the most distinctive chemotaxonomic characters of the sun hebes. The chemical profiles of the species were compared and used to assess the phylogenetic relationships in the group.
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flavonoid profiles in the heliohebe group of new zealand veronica plantaginaceae
Biochemical Systematics and Ecology, 2008Co-Authors: Rilka M Taskova, Renee J Grayer, Tetsuo Kokubun, Ken G Ryan, P J GarnockjonesAbstract:Abstract The Heliohebe group of Veronica (sect. Hebe ) consists of five species occurring in the South Island of New Zealand. These species and a hybrid were analysed for their flavonoids. Five flavone Glycosides were isolated and identified by NMR spectroscopy and three additional Glycosides were detected by LC–UV–MS. Luteolin 7- O -, 3′- O - and 4′- O -glucosides and apigenin 7- O -glucoside were present in all six taxa investigated, 6-hydroxyluteolin Glycosides were found in five and a luteolin caffeoylGlycoside in four taxa, while a hypolaetin 7- O -Glycoside was detected only in Veronica pentasepala . The 3′- O - and 4′- O -glucosides of luteolin are also common in other species of Veronica sect. Hebe (restricted to the Southern Hemisphere), but are rare in Northern Hemisphere species of Veronica and thus act as good chemotaxonomic markers for the section. The relatively simple flavonoid profiles found in the Heliohebe group are plesiomorphic and consistent with the group's status as sister to the Hebe clade. Based on the detected flavonoids, two groups could be distinguished within the Heliohebe clade: (1) Veronica hulkeana , Veronica lavaudiana and Veronica raoulii , characterised by luteolin caffeoylGlycoside, and (2) V. pentasepala and Veronica scrupea , where this compound is replaced by a 6-hydroxyluteolin dihexoside.
Gary Williamson - One of the best experts on this subject based on the ideXlab platform.
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deglycosylation of flavonoid and isoflavonoid Glycosides by human small intestine and liver β glucosidase activity
FEBS Letters, 1998Co-Authors: Susan M Dupont, Saxon Ridley, M J C Rhodes, Michael R A Morgan, Gary WilliamsonAbstract:Abstract 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 3-glucoside, quercetin 3-rhamnoglucoside and naringenin 7-rhamnoglucoside remained unchanged. The Km for hydrolysis of quercetin 4′-glucoside and genistein 7-glucoside was ∼32±12 and ∼14±3 μM in both tissues respectively. The enzymatic activity of the cell-free extracts exhibits similar properties to the cytosolic broad-specificity β-glucosidase previously described in mammals.
