Design, synthesis, docking study and cytotoxic activity evaluation of some novel letrozole analogs

Background Breast cancer is the most common type of female cancer. One class of hormonal therapy for breast cancer drugs -non steroidal aromatase inhibitors- are triazole analogues. In this work, some derivatives of these drugs was designed and synthesized. All synthesized compounds were evaluated for their cytotoxic activities on breast cancer cell lines (MDA-MB-231, T47D and MCF-7). Methods Our synthetic route for designed compounds started from 4-bromotolunitrile which was reacted with 1 H -1,2,4-triazole to afford 4-(4-cyanobenzyl)-1,2,4-triazole. The reaction of later compound with aromatic aldehydes led to formation of the designed compounds. Eleven novel derivatives 1a-k were tested for their cytotoxic activities on three human breast cancer cell lines. Results Among the synthesized compound, 4-[2-(3-chlorophenyl)-1-(1 H -1,2,4-triazol-1-yl)ethenyl]benzonitrile ( 1c ) showed the highest activity against MCF-7 and MDA-MB-231 cell lines and 4-[2-(4-methoxyphenyl)-1-(1 H -1,2,4-triazol-1-yl)ethenyl]benzonitrile ( 1 h ) exhibited highest activity against T47D cell line. According to cytotoxic activities results, compound 4-[2-(4-dimethylamino)-1-(1 H -1,2,4-triazol-1-yl)ethenyl]benzonitrile ( 1 k ) showed comparative activity against T47D and MDA-MB-231 cell lines with compound ( 1 h ) and our reference drug Etoposide. Conclusion In the process of anti-cancer drug discovery, to find new potential anti-breast cancer agents, we designed and synthesized a novel series of letrozole analogs. Cytotoxicity evaluation revealed that compounds ( 1c ) and ( 1 k ) were the most potent compounds with comparative activity with Etoposide. The results revealed that π-π interactions are responsible for the enzyme inhibitions of compounds ( 1 c ) and ( 1 k ).