The most efficient steaming conditions below 200 degrees C for extracting antioxidants from used tea leaves and their reaction behavior during the steaming treatment were investigated. The antioxidative activity of the steamed extracts increased with increasing steaming temperature, and the yield of the ethyl acetate extract fraction from each steamed extract showing the greatest antioxidative ...

The single crystal of (-)-gallocatechin-3-O-gallate (GCg) was prepared using a solution containing an equimolecular amount of GCg and (-)-epigallocatechin-3-O-gallate (EGCg) in water. The crystal structure of GCg determined by X-ray crystallographic analysis was monoclinic with the space group P2(1) at 223 K. Offset pi-pi interactions formed between the A and A rings, B and B rings, and gallate...

Tea is the most common beverage throughout the world. Green tea (Camellia sinensis) is full of flavonoids (1). This herbal drug has a lot of polyphenols, catechin epicatechin, epigallocatechin and epigallocatechin-3-gallate. It also contains other composites like saponins, caffeine, tannins, and some vitamins. Several different investigations have indicated that green tea has hypo-cholesterolae...

Analytical data are reported for 20 flavonoids (as aglycones) determined for more than 60 fresh fruits, vegetables, and nuts collected from four regions across the United States at two times of the year. Sample collection was designed and implemented by the Nutrient Data Laboratory (USDA). Analyses of eight flavan-3-ols (catechin, catechin gallate, epicatechin, epicatechin gallate, epigallocate...

BACKGROUND The blackcurrant (Ribes nigrum L.) is a species of native currant which contains a lot of polyphenolic antioxidants which is used medicinally and has a fundamental role in the maintenance health. MATERIALS, METHODS AND OBJECTIVE: Ultraviolet-visible spectrophotometry and ultraviolet range high performance liquid chromatography (HPLC) were used to characterize the polyphenolic content...

We developed an analytical method for measuring tea catechins in plasma by solid-phase extraction (SPE), followed by HPLC with a coulometric electrochemical detector. The plasma was mixed with an equal volume of acetonitrile to precipitate protein, and catechins in the resulting supernatant were extracted by SPE, using a C18 cartridge. To correct the extraction efficiency, ethyl gallate was sim...