The "Submédio do Vale São Francisco" (S.V.S.F.), located in the Brazilian Northeast, is an emerging winemaking region South America. Touriga Nacional (T.N.) grapes originated Portugal, thrive under climatic conditions found S.V.S.F. effects of extended maceration on different parameters red wine must produced with T.N. from two harvest years were studied. Increased time (16 to 20 days) resulted...

From the fresh leaves of Koelreuteria paniculata Laxm (Sapindaceae), four new compounds, named ethyl p-trigallate (1), 3''-O-galloyl-4'-O-galloyl-4-O-galloyl-gallic acid (2), ethyl p-heptagallate (3) and 3''-galloylquercitrin (4), together with 12 known compounds namely catechin (5), galloylepicatechin (6), isorhamnetin (7), kaempferol-3-O-arabinopyranoside (8), quercetin-3'-O-beta-D-arabinopyr...

Various dietary flavonoids were evaluated in vitro for their inhibitory effect on xanthine oxidase, which has been implicated in oxidative injury to tissue by ischemia-reperfusion. Xanthine oxidase activity was determined by directly measuring uric acid formation by HPLC. The structure-activity relationship revealed that the planar flavones and flavonols with a 7-hydroxyl group such as chrysin,...

The polyphenol content and antioxidant activity of Nonpareil, Carmel, Butte, Sonora, Fritz, Mission, and Monterey almond cultivars harvested over three seasons in California were examined. LC-MS was employed to quantify 16 flavonoids and two phenolic acids in acidified methanol extracts of almond skins. The 3-year mean polyphenol content of cultivars ranged from 4.0 to 10.7 mg/100 g almonds. Is...

Seven bee pollen samples (C1-C7) with different palynological sources were harvested from Pindamonhangaba municipality (Southeast Brazil). Methanol extracts of untreated samples (control), samples frozen at -18 °C and samples frozen and then dried were analyzed by HPLC/PAD/ESI/MS/MS. Flavonoid diglycosides of quercetin, kaempferol, isorhamnetin and patuletin were detected, together with hydroxy...

Flavonoids are bioactive food compounds with potential lipid-lowering effects. Commercially available enzymatic assays are widely used to determine free fatty acid (FFA) and triglyceride (TG) levels both in vivo in plasma or serum and in vitro in cell culture medium or cell lysate. However, we have observed that various flavonoids interfere with peroxidases used in these enzymatic assays, resul...

In recent years, the scientific interest and particularly economic significance of halophytic plants has been highly demanding due to medicinal nutraceutical potential its bioactive compounds. A xero-halophyte Bassia indica is deemed be a very cheap source natural entities without chemical or biological investigation. this context, new acylated flavonol tetraglycoside, kaempferol-3-O-?-d-glucop...

Four O-acylated flavonol glycosides, new in the plant kingdom, were isolated from the needles of Pseudotsuga menziesii. Their structures were established by 1D and 2D NMR and MS data as: daglesioside I [kaempferol 3-O-[2",5"-O-(4''',4(IV)-dihydroxy)-beta-truxinoyl]-alpha-L-arabinofuranoside] (1), daglesioside II [kaempferol 3-O-[2",5"-O-(4"'-hydroxy)-beta-truxinoyl]-alpha-L-arabinofuranoside] (...

Sea buckthorn (Hippophaë rhamnoides L.) is a rich source of flavonols, especially isorhamnetin. Most prospective cohort studies have indicated some degree of inverse association between flavonoid intake and coronary heart disease. Animal and human studies suggest that sea buckthorn flavonoids may scavenge free radicals, lower blood viscosity, and enhance cardiac function. The effects of flavono...