A novel series of Mannich bases of 1, 3-dihydroxyxanthone derivatives were designed and synthesized. The
chemical structures of the compounds were characterized by IR, MS and NMR spectra. Their in vitro toxicities on six tumor
cell lines including NCI-H460 (lung cancer), TCA-8113 (tongue squamous cell carcinomas), BEL-7402 (liver cancer),
HepG2 (hepatocarcinoma), SGC-7901 (gastric carcinoma) and T24 (urinary bladder carcinoma) were studied
through MTT assay. The results showed that most of the compounds displayed mild to good inhibitory activities on the
cancer cell lines. Some preliminary structure-activity relationships were also discussed.