Four cultivars (Bronowicka Ostra, Cyklon, Tornado, and Tajfun) of pepper fruit Capsicum annuum L. were studied for phenolics contents and antioxidant activity. Two fractions of phenolics, flavonoids (with phenolic acids) and capsaicinoids, were isolated from the pericarp of pepper fruit at two growth stages (green and red) and were studied for their antioxidant capacity. Both fractions from red...

Lotus (Nelumbo nucifera) leaves, a traditional Chinese medicinal herb, are rich in flavonoids. In an effort to thoroughly analyze their flavonoid components, macroporous resin chromatography coupled with HPLC-MS/MS was employed to simultaneously enrich and identify flavonoids from lotus leaves. Flavonoids extracted from lotus leaves were selectively enriched in the macroporous resin column, elu...

Three quercetin glycosides, quercetin 5-O-beta-D-glucoside, quercetin 7-O-beta-D-glucoside, and quercetin 4'-O-beta-D-glucoside, and two kaempferol glycosides, kaempferol 5-O-beta-D-glucoside and kaempferol 7-O-beta-D-glucoside, along with their aglycones, quercetin and kaempferol, were isolated from an ethanolic extract of Sasamayu cocoon shells. The chemical structures were characterized by c...

Accumulated data have suggested that the hydroxyl groups of flavonoids are important for their bioactive function. To directly demonstrate the role of hydroxyl groups, we synthesized a derivative of quercetin, 3,7,3',4'-O-tetrabenzylquercetin (4Bn-Q) that substituted the hydroxyl groups of quercetin with benzyl groups, and then evaluated the ability to inhibit cell proliferation and cause apopt...

Fruits of sweet orange (Citrus sinensis), a popular commercial Citrus species, contain high concentrations of flavonoids beneficial to human health. These fruits predominantly accumulate O-glycosylated flavonoids, in which the disaccharides [neohesperidose (rhamnosyl-α-1,2-glucose) or rutinose (rhamnosyl-α-1,6-glucose)] are linked to the flavonoid aglycones through the 3- or 7-hydroxyl sites. T...

Quercetin is a natural flavonoid widely distributed in human diet and functional foods. Quercetin 3-O-β-glucuronide (Q3G) is present in wine and some medicinal plants. Quercetin and Q3G may be metabolized from each other in vivo. While quercetin has been the subject of many studies, the pharmacokinetic profiles of quercetin and Q3G (in animals) have not yet been compared. Herein, we prepared a ...

In this present work the fresh flowers of Allamanda Cathartica Linn. were collected and the solution of Allamanda Cathartica was extracted with 90% methanol under reflux. The alcoholic extract was concentrated in vacuo and the aqueous concentrate, successively fractionated with benzene, peroxide free diethylether and ethylacetate. The benzene fraction was not yielding any isolable material. The...

Two new stilbene glycosides, 5-O-methyl-(E)-resveratrol 3-O-beta-d-glucopyranoside (1) and 5-O-methyl-(E)-resveratrol 3-O-beta-D-apiofuranosyl-(1-->6)-beta-d-glucopyranoside (2), were isolated from the leaves of Acer mono, along with seven known compounds. Among these compounds, 1, 2, and quercetin (3) showed significant hepatoprotective activities against H(2)O(2)-induced toxicity in primary c...

A stem ethanol extract of Bauhinia strychnifolia and its compounds were investigated for their anti-HIV-1 integrase (IN) and anti-allergic activities. From bioassay-guided isolation, five compounds including quercetin (1), 3,5,7,3',5'pentahydroxyflavanonol-3-O--L-rhamnopyranoside (2), 3,5,7-trihydroxychromone-3--L-rhamnopyranoside (3) and a mixture of -sitosterol (4) and stigmasterol (5) wer...

BACKGROUND Limonium bicolor, a halophytic species, can grow in saline or saline-alkali soil, is well known as a traditional Chinese medicine. Recently it attracted much attention for its treatment for cancer. OBJECTIVE The present study was performed to evaluate this species from the phytochemical standpoint and the possible relationship between the antitumor activity and its natural products...