*4.1. The Source of Epigallocatechin-3-Gallate*

4.1.1. Epigallocatechin-3-Gallate Extraction

The extraction process and purity measurement of extracted EGCG had been published elsewhere [40]. Briefly, we dispersed five grams of green tea powder (Ten Ren Tea Co., Ltd., Taiwan) in 65% ethanol and refluxed at 100 ◦C for 15 min. The rotary evaporator (N-1000, Eyela, Tokyo, Japan) was used to remove ethanol. We then purified the dried solid in two consecutive extraction processes. The solid dispersed in distilled water was extracted against an equal volume of chloroform. The resulting water phase was then extracted against ethyl acetate. Next, the extracts were obtained from an ethyl acetate phase followed by rotary evaporation and then stored in the containers at low humidity before use.
