A para-amino substituent on the D-ring of green tea polyphenol epigallocatechin-3-gallate as a novel proteasome inhibitor and cancer cell apoptosis inducer Original Research Article

Analogs of (−)-EGCG containing a para-amino group on the D-ring in place of the hydroxyl groups have been synthesized and their proteasome inhibitory activities were studied. We found that, the O-acetylated (−)-EGCG analogs possessing a p-NH2 or p-NHBoc (Boc; tert-butoxycarbonyl) D-ring (5 and 7) act as novel tumor cellular proteasome inhibitors and apoptosis inducers with potency similar to natural (−)-EGCG and similar to (−)-EGCG peracetate. These data suggest that the acetylated amino-GTP analogs have the potential to be developed into novel anticancer agents.