To investigate the effects of flavonoids on free radical-mediated biological membrane damage and the interaction of flavonoids with heme proteins, we studied the effects of quercetin, its glycosides (rutin and quercetin-3-O-glucoside), morin and (-)epicatechin on the hemolysis of the bovine erythrocytes induced by the hydrophilic free radical initiator, 2,2'-azobis(2-amidinopropane)dihydrochlor...

In-silico study was performed to find the pharmacodynamics, toxicity profiles and biological activities of three phytochemicals isolated from Limoniastrum feei (Plumbagenaceae). Online pharmacokinetic tools were used to estimate the potential of Quercetin, kaempferol-3-O-β-D-glucopyranoside (astragalin) and quercitin-7-O-β-D-glucopyranoside as specific drugs. Then the prediction of potential ta...

BACKGROUND Hydrogen peroxide is continuously generated in living cells through metabolic pathways and serves as a source of reactive oxygen species. Beyond the threshold level, it damages cells and causes several human disorders, including cancer. METHODS Effect of isolated 3-O-methyl quercetin and kaempferol on H2O2 induced cytotoxicity, ROS formation, plasma membrane damage, loss of mitocho...

A new compound, kaempferol 3-O-(2''-O-galloylrutinoside) (1), was isolated from the white flower of Nymphaea candida, together with nine known flavonol glycosides, kaempferol (2), kaempferol 3-O-beta-D-glucopyranoside (3), kaempferol 3-O-alpha-l-rhamnopyranoside (4), kaempferol 3-O-alpha-l-rhamnopyranosylglucopyranoside (5), kaempferol 7-O-beta-D-glucopyranoside 3-(O-alpha-l-rhamnopyranosylgluc...

Angelica shikokiana is widely marketed in Japan as a dietary food supplement. With a focus on neurodegenerative conditions such as Alzheimer's disease, the aerial part was extracted and through bio-guided fractionation, fifteen compounds [α-glutinol, β-amyrin, kaempferol, luteolin, quercetin, kaempferol-3-O-glucoside, kaempferol-3-O-rutinoside, methyl chlorogenate, chlorogenic acid, hyuganin E,...

Flavonoids exhibit antioxidant behavior believed to be related to their metal ion chelation ability. We investigate the complexation mechanism of several flavonoids, quercetin, luteolin, galangin, kaempferol, and chrysin, with iron, the most abundant type of metal ions in the body, through first-principles electronic structure calculations based on density functional theory (DFT). We find that ...

Two new prenylated flavonoids, named scariosin (1) and isorhynchospermin (2) were isolated from the leaves of paracalyx scariosa together with kaempferol, quercetin, kaempferol 3-O- rutinoside and rutin. The structures of (1) and (2) were characterized as 8-C- prenyl- taxifolin 7,3'-dimethylether and 6-C-prenylquercetin 7,4'-dimethylether by their chemical and spectra data, respectively.

Three new flavonol malonylrhamnosides, 3-O-(4"-O-malonyl)-alpha-L-rhamnopyranosides of mearnsetin, myricetin and quercetin respectively, together with the corresponding mearnsitrin, myricitrin, quercitrin and the 4-O-methyl phloracetophenone 2-O-beta-D-glucopyranoside, were isolated from the leaves of Ribes alpinum and fully characterized by spectrocopic methods including 2D NMR.