Synthesis and Insilico Assessment of Novel Benzothiazole Series against Human DNA Topo Isomerase I

Human topoisomerase I (Top1) plays a pivotal role in cell replication and transcription, and therefore is an important anti-cancer target. Thiazolidinone and Azetidinone derivatives of 6-substituted 2-aminobenzothiazoles were synthesized and tested for their topoisomerase inhibitory activity and cytotoxicity by computational methods. Among the synthesized thiazolidinone and azetidinone analogs, compound 5avi and 6cvi exhibited potent topo I inhibitory activity and strong cytotoxicity. Interestingly, consistency was observed between the cytotoxicities and topo I activities in these thiazolidinone and azetidinone analogs, suggesting that the target of compound 5avi and 6cvi is limited to topo I. Molecular docking studies were performed with the Molecular Operating Environment (London DG Scoring Function) program to afford the ideal interaction mode of the compound into the binding site of the DNA–topo I complex in order to clarify the topo I activity of 5avi and 6cvi..