Separation of Polyphenols and Caffeine from the Acetone Extract of Fermented Tea Leaves (Camellia sinensis) Using High-Performance Countercurrent Chromatography

摘要

Leaves from Camellia sienensis are a popular natural source of various beverage worldwide, and contain caffeine and polyphenols derived from catechin analogues. In the current study, caffeine (CAF, >1) and three tea polyphenols including (−)-epigallocatechin 3-O-gallate (EGCg, >2), (−)-gallocatechin 3-O-gallate (GCg, >3), and (−)-epicatechin 3-O-gallate (ECg, >4) were isolated and purified by flow-rate gradient high-performance countercurrent chromatography (HPCCC) using a two-phase solvent system composed of n-hexane–ethyl acetate–methanol–water (1:9:1:9, v/v). Two hundred milligrams of acetone-soluble extract from fermented C. sinensis leaves was separated by HPCCC to give >1 (25.4 mg), >2 (16.3 mg), >3 (11.1 mg) and >4 (4.4 mg) with purities over 98%. The structures of >1–>4 were elucidated by QTOF-MS, as well as ¹H- and ¹³C-NMR, and the obtained data were compared to the previously reported values.