Résumé
OBJECTIVE: To explore an efficient structure modification route to transform antibacterial fluoroquinolones to antitumor ones. METHODS: Compound A[1,3,4] oxadiazol-5-thiol 3 derived from ofloxacin 1 was subjected to nucleophilic substitution with each of chloromethyl-1,3,4-oxadiazoles 4a-4g gave di-oxadiazolyl methylsulfides 5a-5g, followed by a quaternization to form the corresponding methiodides 6a-6g, respectively. The in vitro antitumor activity of the title compounds 5a-5g and 6a-6g against three cancer cell lines was evaluated by MTT method. RESULTS: Fourteen title compunds were synthesized and the structures were characterized by corresponding spectral data. The bioactive assay showed that compounds 5a-5g and 6a-6g exhibited a potential anticancer activity (IC50 < 25 μmol · L-1). The activity of the quaternary ammoniums 6a-6g was higher than that of the corresponding free bases 5a-5g. CONCLUSION: The design and synthesis of antitumor fluoroquinolone based on antibacterial fluoroquinolone C-3 heterocycle are worthy of further study.