Genotoxic potentials and eukaryotic DNA topoisomerase I inhibitory effects of some benzoxazine derivatives

Benzoxazines are heterocyclic compounds which have been used as intermediates in the synthesis of many heterocyclic structures of biological importance as it has been reported that some of the benzoxazines were effective in promoting apoptosis and inhibiting cell proliferation. Present study contains experimental data that showed genotoxic potentials and inhibitory effects on eukaryotic DNA topoisomerase I of 16 newly synthesized benzoxazine derivatives. By rec assay, the bacterial genotoxicity assay, only four tested compounds were found genotoxic at different concentrations and four compounds showed reverse effect. RC50 values evaluated by rec assay revealed that BS5 was the most genotoxic and BS4 was the most cytotoxic compound at micromolar concentration. Compounds were also tested for their inhibitory effects on eukaryotic DNA topoisomerase I enzyme and it was found that 14 of the compounds had inhibitory effects on eukaryotic DNA topoisomerase I enzyme. The most active compounds, BS18 and BS4, showed higher inhibitory activities than the positive control drug camptothecin which is a well-known commercial topoisomerase I inhibitor.