Potent antitumor activity of synthetic 1,2-naphthoquinones and 1,4-naphthoquinones

Rhinacanthone (1) and two 1,2-pyranonaphthoquinones (2,3) were synthesized and found to show very potent cytotoxicity against three cancer cell lines (KB, HeLa and HepG(2)) with IC50 values of 0.92-9.63 muM, whereas the corresponding hydroxylated derivative 4 had reduced cytotoxicity (IC50 values of 7.61-24.13 muM). Three 1,2-furanonaphthoquinone derivatives (5-7) were also synthesized with similar cytotoxicity as 1,2-pyranonaphthoquinones. In comparison to 1,2-naphthoquinones, six w1,4-naphthoquinones derivatives fused with pyran ring (8-10) and furan ring (11-13) were synthesized and they showed less cytotoxicity or inactive to the cancer cell lines. Moreover, compound 13 had significant cytotoxicity against HeLa cell line (IC50 value of 9.25 muM) while it showed no toxic to vero cell. (C) 2003 Elsevier Science Ltd. All rights reserved.