Abstract
(−)-Epigallocatechin is a chemoprotective polyphenolic compound found in green tea.
Its low abundance in tea increases the cost and difficulty of obtaining sufficient
(−)-epigallocatechin to conduct research on (−)-epigallocatechin-mediated health benefits.
We developed a convenient and economical method for preparing (−)-epigallocatechin
from a commercial green tea extract in a sufficient quantity to carry out mechanistic
studies of the pure compound. Crude epigallocatechin gallate was isolated from the
tea extract by silica gel column chromatography, and was then hydrolyzed with immobilized
tannase. The (−)-epigallocatechin found in the hydrolyzed products was extracted into
ethyl acetate and purified by Sephadex LH-20 to produce (−)-epigallocatechin. Very
pure (−)-epigallocatechin (93.7 %) was obtained and its identity was confirmed by
ESI-MS and HPLC. The overall yield was 10 % by mass of the initial green tea extract
obtained as pure (−)-epigallocatechin. No specialized equipment was required, and
the solvents and chromatographic supports used were inexpensive and readily available.
Key words
Camellia sinensis
- Theaceae - catechin - flavonoid - polyphenol - antioxidant - tea
