Synthesis and biological evaluation of novel benzo[b]xanthone derivatives as potential antitumor agents

Nine novel AMinoalkoxy substituted benzo[b]xanthones (3a–i) were synthesized. Their antitumor activities were evaluated in five human solid tumor cell lines, including Hep-G2, BEL-7402, HeLa, MGC-803 and CNE, by the MTT (2-(4,5-dimethyl-thiazol-2-yl)-3,5-diphenyl-2H-tetrazolium bromide) method. The results showed that most of the compounds displayed moderate to good inhibitory activities on the tested cancer cell lines in vitro, AMong them compounds 3a and 3h showed higher antitumor activity than the other tested compounds against most cell lines. The influences of two kinds of structural factors, i.e., the terminal AMino group and length of the carbon spacers, on the anticancer activities were explored to discuss preliminary structure–activity relationships.