title: New flavan-3-ol dimer from green tea produced from Camellia taliensis in the Ai-Lao mountains of Southwest China.
abstract: Camellia taliensis (W. W. Smith) Melchior, belonging to the genus Camellia sect. Thea (Theaceae), is an endemic species distributed from the west and southwest of Yunnan province, China, to the north of Myanmar. Known as a wild tea tree, its leaves have been used commonly for producing tea beverages by the local people of its growing area. One new flavan-3-ol dimer, talienbisflavan A (1), was isolated from green tea prepared from the leaves of C. taliensis collected from the east side of the Ai-Lao mountains, Yuanjiang county of Yunnan province, China. In addition, five hydrolyzable tannins (2-6), five flavonols and flavonol glycosides (9-13), three flavan-3-ols (14-16), nine simple phenolic compounds and glycosides (7, 8, and 17-23), and caffeine (24) were identified. Their structures were determined by detailed spectroscopic analysis. All of the isolated phenolic compounds were tested for their antioxidant activities by DPPH and ABTS(+) radical scavenging assays. The contents of its main chemical compositions were also compared with those collected from the Lincang area of Yunnan province by high-performance liquid chromatography analysis.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources of West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China.
authors.forename: Li-Fang
authors.initials: LF
authors.lastname: Zhu
authors.forename: Min
authors.initials: M
authors.lastname: Xu
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Zhu
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Shi-Xiong
authors.initials: SX
authors.lastname: Yang
authors.forename: Chong-Ren
authors.initials: CR
authors.lastname: Yang
authors.forename: Ying-Jun
authors.initials: YJ
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001628:Beverages; D028244:Camellia / Q000737:chemistry*; D002681:China; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019281:Dimerization; D005419:Flavonoids / Q000737:chemistry*; D044948:Flavonols / Q000032:analysis; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D015394:Molecular Structure; D013634:Tannins / Q000032:analysis
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D044948:Flavonols; D016166:Free Radical Scavengers; D013634:Tannins; C585849:talienbisflavan A; C404987:flavan-3-ol