Title
Novel acetylcholinesterase inhibitors from Zijuan tea and biosynthetic pathway of caffeoylated catechin in tea plant
Author
Wei Wang, Xi-Wen Fu, Xin-Long Dai, Fang Hua, Gang-Xiu Chu, Ming-Jie Chu, Feng-Lin Hu, Tie-Jun Ling, Li-Ping Gao, Zhong-Wen Xie, Xiao-Chun Wan, Guan-Hu Bao
Year
2017
Journal
Food Chemistry
Abstract
Zijuan tea is a special cultivar of Yunnan broad-leaf tea (Camellia sinensis var. assamica) with purple buds, leaves, and stems. Phytochemical study on this tea led to the discovery of three hydroxycinnamoylated catechins (HCCs) (1-3), seven other catechins (4-10), three proanthocyanidins (11-13), five flavones and flavone glycosides (14-18), two alkaloids (19, 20), one steroid (21), and one phenylpropanoid glycoside (22). The isolation and structural elucidation of the caffeoylated catechin (1) by means of spectroscopic techniques was described. We also provide the first evidence that 1 is synthesized via a two-step pathway in tea plant. The three HCCs (1-3) were investigated on their bioactivity through molecular modeling simulation and biochemical experiments. Our results show that they bind acetylcholinesterase (AChE) tightly and have strong AChE inhibitory activity with IC50 value at 2.49, 11.41, 62.26 μM, respectively.
Instrument
J-815
Keywords
Circular dichroism, Stereochemistry, Food science