저온 플라즈마 처리된 녹차 유래의 최종당화산물 생성 억제물질의 동정

Abstract

Green tea (Camellia sinensis) with abundant phenolic compounds is considered to a major dietary source of flavan 3-ols such as (−)-epigallocatechin gallate (EGCG). Here, we assessed the effects of non-thermal dielectric barrier discharge (DBD) plasma on green tea extract using spectroscopy and bioassays. Plasma-induced structural changes in EGCG in green tea resulted in the isolation of two methylene-bridge dimers, oolonghomobisflavan A (1) and B (2). The structures of these compounds were characterized using nuclear magnetic resonance and mass spectroscopy data. The symmetric dimer 1 connected by a methylene linkage was the most potent inhibitor of advanced glycation end products (AGEs) formation (IC50, 8.2±0.5 μM). The radical scavenging capacity of against hydroxyl, and stereoisomers 1 and 2 was more potent than that of the positive control ((+)-catechin). These major products purified by treating green tea with DBD plasma for 60 min were quantified by HPLC. Our results provide evidence that structural changes of EGCG in green tea extract induced by plasma might enhance biological efficacy.