查看文章

(−)-Epigallocatechin gallate (EGCG), the most abundant tea catechin, has been proposed to be beneficial to human health based on its strong antioxidative and other biological activities in vitro. Inadequate knowledge regarding the bioavailability and biotransformation of EGCG in humans, however, has limited our understanding of its possible beneficial health effects. In this study, 4‘,4‘ ‘-di-O-methyl-EGCG (4‘,4‘ ‘-DiMeEGCG) was detected in human plasma and urine by LC/MS/MS following green tea ingestion. Both 4‘,4‘ ‘-DiMeEGCG and EGCG reached peak plasma values (20.5 ± 7.7 and 145.4 ± 31.6 nM, respectively, in 4 subjects) at 2 h after the dose. The half-lives of 4‘,4‘ ‘-DiMeEGCG and EGCG were 4.1 ± 0.8 and 2.7 ± 0.9 h, respectively. The cumulative urinary excretion of 4‘,4‘ ‘-DiMeEGCG during a 24 h period was 140.3 ± 48.6 μg, about 5-fold higher than that of EGCG, but the excreted 4‘,4 …