ANTITUMOR-ACTIVITY OF 2(S)-5,2',5'-TRIHYDROXY-7,8-DIMETHOXYFLAVANONE AND ITS ANALOGS

In an effort to increase of the antitumor activity of 2(S)-5,2 ',5 '-t rihydroxy-7,8-dimethoxyflavanone isolated from Scutellaria indica, we synthesized its analogues, II, III and IV. They showed potent cytotoxi city in vitro against cancer cell lines, L1210, K562 and A549. On the basis of ED50 values against the cancer cell lines, III exhibited abou t 2-7 times stronger activity than I against various cell lines. We te sted the antitumor activity of the analogues against Sarcoma 180 cells in vivo and evaluated the structure-activity relationship. The antitu mor activity appeared to be related to the hydrogen bond between carbo nyl group at C-4 and hydroxyl group at C-5, in contrast to cytotoxic a ction.