Synthesis and antitumor, antityrosinase, and antiplatelet aggregation activities of xanthone.

In the present study, five fluorine substituted and three chlorine substituted 1,3-dihydroxyxanthones were synthesized in one step. The yields ranged from 48% to 72%. Among them, compounds 12 and 15-18 were reported for the first time. The antitumor, antityrosinase and antiplatelet aggregation activities of all or part of compounds 1-19 were evaluated. Compounds 1, 2, 4, 6-7, 10-15 and 19 exhibited enhanced cytotoxicity against certain cancer cells. Compound 10, containing 2,4-difluorophenyl at the C7 position, particularly exhibited superior antitumor activity. The inhibition rate of compound 18 against tyrosinase was approximately 22%. Compounds 1-3, 6, 9, 12 and 18, 19 exhibited obvious inhibitory platelet aggregation induced by ADP in rats. Moreover, the effects of compounds 2 and 3 were more pronounced. These results demonstrated that compounds 1-4, 6-7, 9-15 and 19 were promising leads for further structural modification. [ABSTRACT FROM AUTHOR]