title: Phenolic antioxidants from green tea produced from Camellia taliensis.
abstract: The chemical constituents of green tea prepared from the leaves of Camellia taliensis (W. W. Smith) Melchior (Theaceae) were investigated for the first time. Of these, 19 phenolic compounds including 8 hydrolyzable tannins (1-8), 6 catechin derivatives (9-14), 3 quinic acid aromatic esters (15-17), and 2 simple phenolics (18, 19) were identified, along with caffeine (20). Their antioxidant activities were evaluated by DPPH radical scavenging and tyrosinase inhibitory assays. Moreover, the chemical composition was compared with that in the cultivated tea plant, C. sinensis var. assamica, by HPLC analysis. It was noted that C. taliensis has similar chemical features with the cultivated tea plant; that is, both of them contain rich flavan-3-ols and caffeine. In addition, there are abundant hydrolyzable tannins as specific characteristic constituents contained in the leaves of C. taliensis. Therein, 1,2-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-beta-D-glucopyranose (8), as a major compound in C. taliensis, showed remarkable antioxidant activity. The results suggested that C. taliensis could be a valuable plant resource for the production of tea.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.
authors.forename: Da-Fang
authors.initials: DF
authors.lastname: Gao
authors.forename: Ying-Jun
authors.initials: YJ
authors.lastname: Zhang
authors.forename: Chong-Ren
authors.initials: CR
authors.lastname: Yang
authors.forename: Ke-Ke
authors.initials: KK
authors.lastname: Chen
authors.forename: Hong-Jian
authors.initials: HJ
authors.lastname: Jiang
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D001628:Beverages / Q000032:analysis*; D028244:Camellia / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives / Q000032:analysis; D010636:Phenols / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry*; D011801:Quinic Acid / Q000031:analogs & derivatives / Q000032:analysis; D013634:Tannins / Q000032:analysis
chemical_list: D000975:Antioxidants; D010636:Phenols; D013634:Tannins; D011801:Quinic Acid; D002392:Catechin