Sugar-sugar glycosyltransferases play an important role in structural diversity of small molecule glycosides in higher plants. We isolated a cDNA clone encoding a sugar-sugar glucosyltransferase (CaUGT3) catalyzing 1,6-glucosylation of flavonol and flavone glucosides for the first time from Catharanthus roseus. CaUGT3 exhibited a unique glucosyl chain elongation activity forming not only gentio...

Microctis Folium, the leaves of Microcos paniculata L., is a commonly used herbal tea material. The methanol extract of Microctis Folium and its principle compounds vitexin (1), isovitexin (2) and isorhamnetin 3-O-β-D-rutinoside (3) were investigated for their α-glucosidase inhibitory effects. The extract showed strong α-glucosidase inhibitory effect (IC₅₀ = 61.30 μg/mL) and the three flavonoid...

Five flavonoid glycosides were isolated from the n-butanol soluble fraction of the ethanolic extract of Rapistrum rugosum and their structures were assigned from (1)H- and (13)C-NMR spectra (DEPT) with 2D NMR as quercetin-3-O-α-L-rhamnopyranoside (1), quercetin-3-O- β-D-xyloside (2), quercetin, 3-O-α-L-arabinopyranoside,7-O-α-L-rhamnopyranoside (3), kaempferol 3-O-α-L-arabinopyranoside, 7-O-α-L...

Rhizopus azygosporus Yuan et Jong (ATCC 48108), a starter culture for fermented soybean tempeh, produces β-glucosidases that cleave flavonoid glycosides into aglycones during fermentation. However, recent data suggest that fermentation of a flavonoid glycoside-rich extract with this strain did not result in the production of aglycones. Thus, in this paper, flavonoid metabolism of this strain wa...

Elsholtzia rugulosa Hemsl. is known in China as a local herbal tea, medicinal herb and honey plant. Chemical examination of E. rugulosa led to the isolation of two new flavonoid glycosides, apigenin 4'-O-alpha-D-glucopyranoside (1) and 5,7,3',4'-tetrahydroxy-5'-C-prenylflavone-7-O-beta-D-glucopyranoside (2), together with nine known flavonoids. Their structures were elucidated on the basis of s...

Human serum albumin (HSA) binds a variety of xenobiotics, including flavonoids and warfarin. The binding of another ligand to the IIA binding site on HSA can cause warfarin displacement and potentially the elevation of its free concentration in blood. Studies dealing with flavonoid-induced warfarin displacement from HSA provided controversial results: estimated risk of displacement ranged from ...

13C-NMR, Apigenin, Kaempferol, Flavonoid, Biosynthesis Cell suspension cultures of parsley (Petroselinum hortense) were incubated with [l,2-13C2]acetate during a period of active flavonoid production. The flavonoid glycosides were extracted with ethanol, hydrolyzed in dilute acid, and the aglycones purified by chromatography. Apigenin, a flavone, and kaempferol, a flavonol, were analyzed at 67....