Abstract:

Xanthono-pyridine(2)was synthesized by means of Ullmann method from o-iodobenzoic acid and 8-hydroxyquinoline; then compound 2 was treated with methyl iodide, ethyl iodide to afford quaternary ammonium salts 3a and 3b, respectively. Their structures were confirmed by IR, NMR, MS and elemental analysis. The two target compounds′ cytotoxic activities against four human cancer cell lines including A2780(ovarian cancer), Hela(cervical cancer), SPC-A(liver cancer) and KB(oral epithelial carcinoma), were evaluated in vitro by MTT method, the results show that the activities of both salts 3a and 3b were better than that of the positive control 5-Fu. Ethidium bromide displacement assay showed that the apparent binding constants(Kapp) of compound 3a and 3b with CT-DNA(calf thymus) were 3.91×105 L/mol and 2.72×105 L/mol, respectively, which suggests that their anti-cancer capabilities might be associated with their interactions with DNA. Their inhibitory activities on acetylcholinesterase(AChE) and butyrylcholinersterase(BuChE) were studied as well. The two compounds showed better and almost equivalent inhibitory activity on AChE. The IC50 values reach μmol/L level, which are close to that of Galantamine·HBr; enzyme kinetic study indicates that the type of their inhibition on AChE was noncompetitive action.