Flavan-3-Ols and biological implication of Camellia sinensis (L) O Kuntze

Tea, throughout its history, has been one of the most popular non-alcoholic beverages in the world. All cultivated tea is generally assigned to one species Camellia sinensis (L) O Kuntze, most of the tea grown in the world today is highly heterogeneous as a result of the large-scale dispersal of the tea plant during the long history of its cultivation, its out-breeding nature, and the free hybridization between geographical races. Based on the extent of fermentation the tea shoots undergo during processing, teas divided into three major groups: unfermented tea (green tea), semi-fermented tea (oolong tea) and fully fermented tea (black tea). Fresh tea leaves are rich in flavonoids - a group of phenolic compounds known as catechins. Tea is being advocated to be a functional food and an important source of dietary flavonoids. Epidemiological studies carried out during the last three decades suggested that green tea catechins have nutraceutical and therapeutic attributes. Green tea catechins have been reported to possess antimicrobial, antiallergic, anti-carcinogenic and antioxidant activities. EGCG was reported to be the most active compound with 32% potency.