Synthesis, antimicrobial, antiquorum-sensing, antitumor and cytotoxic activities of new series of cyclopenta(hepta)[b]thiophene and fused cyclohepta[b]thiophene analogs

Abstract

New series of cyclopenta(hepta)[b]thiophene and fused cyclohepta[b]thiophene analogs were synthesized. The new analogs were assessed for antibacterial efficacy toward Escherichia coli ATCC 12435, Bacillus cereus UW 85 and Staphylococcus aureus. Compounds 5a, 6b and 12 showed eminent activity toward all selected bacterial strains compared to ampicillin. The antifungal efficacy of the same analogs was also examined toward Candida albicans and Aspergillus fumigatus 293, whereas 5a,b and 12 showed excellent efficacy toward both of the tested fungi. Moreover, 4b, 6a, 14a and 17 demonstrated interesting antifungal efficacy toward A. fumigatus. The same analogs were assessed for antiquorum-sensing efficacy toward Chromobacterium violacium ATCC 12472, whereas 5a, 12 and 15a demonstrated moderate activity. The new analogs were also esteemed for in vitro antitumor activity over HepG2, MCF-7 and HT-29 cancer cell lines. Results indicated that 6b and 10 are the most potent analogs against the three tested cell lines. In addition, 5a, 6a, 7 and 15a displayed interesting activity toward all tested cell lines. The active in vitro antitumor analogs were screened for in vivo antitumor activity over EAC in mice as well as in vitro cytotoxicity toward W138 human normal cell line. Results demonstrated that 6a,b and 10 have the highest in vivo activity, and that all tested compounds were found to be less cytotoxic than 5-FU toward W138 normal cell line. The DNA-binding affinity of the active antimicrobial and/or antitumor analogs was also assessed, whereas 4a, 5b, 10 and 15a exhibited the highest affinity. In silico studies affirmed that the inspected compounds are compatible with Lipinski's rule of five with expected good oral absorption.