Design, synthesis, computational insights, and evaluation of tetrazole containing donepezil derivatives as antibiofilm, antimicrobial, and anticancer agents with doxorubicin

Abstract

Tetrazole is an active functional group commonly used in bioactivity studies. It is found in the structures of commercially available drugs such as losartan, cilostazol, and oteseconazole, and is also frequently involved in anticancer studies. Therefore, tetrazole-containing donepezil derivatives (2a-s) were synthesised and evaluated for antimicrobial, antibiofilm, and anticancer activities. Compounds were tested against Candida albicans (ATCC 10231), Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213), and the triple-negative breast cancer (TNBC) cell line MDA-MB-231. Notably, several derivatives showed potent inhibition of both Grampositive, Gram-negative bacteria and biofilm formation, as well as C. albicans. In the anticancer assays, compounds were screened via MTT assays, and their cytotoxicity was also assessed in combination with doxorubicin. The MDA-MB-231 cell line was selected due to its aggressive, chemoresistant phenotype representative of TNBC, a subtype with limited treatment options. Some compounds exhibited moderate to strong synergistic effects with doxorubicin, suggesting potential as adjuvant therapy candidates. Molecular docking and 100 ns molecular dynamics simulation analyses of compounds interacting with the enzymes Dihydropteroate Synthase (DHPS) and Sterol 14-alpha Demethylase (CYP51) were performed. Docking results revealed that compounds 2o and 2h exhibited similar or superior interaction profiles with target enzymes compared to natural substrates and reference ligands. These findings support the multifunctional therapeutic potential of tetrazole-containing donepezil derivatives for further preclinical investigation in infectious and oncologic applications.