Synthesis, DFT Calculations, In Silico Studies, and Antimicrobial Evaluation of Benzimidazole-Thiadiazole Derivatives.

In this study, a series of new benzimidazole-thiadiazole hybrids were synthesized, and the synthesized compounds were screened for their antimicrobial activities against eight species of pathogenic bacteria and three fungal species. Azithromycin, voriconazole, and fluconazole were used as reference drugs in the mtt assay. Among them, compounds 5f and 5h showed potent antifungal activity against C. albicans with a MIC of 3.90 µg/mL. Further, the results of the antimicrobial assay for compounds 5a, 5b, 5f, and 5h proved to be potent against E. faecalis (ATCC 2942) on the basis of an acceptable MIC value of 3.90 µg/mL. The cytotoxic effects of compounds that are effective as a result of their antimicrobial activity on healthy mouse fibroblast cells (L929) were evaluated. According to HOMO-LUMO analysis, compound 5h (with the lower ΔE = 3.417 eV) is chemically more reactive than the other molecules, which is compatible with the highest antibacterial and antifungal activity results. A molecular docking study was performed to understand their binding modes within the sterol 14-α demethylase active site and to interpret their promising fungal inhibitory activities. Molecular dynamics (MD) simulations of the most potent compounds 5f and 5h were found to be quite stable in the active site of the 14-α demethylase (5TZ1) protein.

Design, Synthesis, and Biological Evaluation Studies of Novel Naphthalene-Chalcone Hybrids As Antimicrobial, Anticandidal, Anticancer, and VEGFR-2 Inhibitors.

Cancer is a progressive disease that is frequently encountered worldwide. The incidence of cancer is increasing with the changing living conditions around the world. The side-effect profile of existing drugs and the resistance developing in long-term use increase the need for novel drugs. In addition, cancer patients are not resistant to bacterial and fungal infections due to the suppression of the immune system during the treatment. Rather than adding a new antibacterial or antifungal drug to the current treatment plan, the fact that the drug with anticancer activity has these effects (antibacterial and antifungal) will increase the patient's quality of life. For this purpose, in this study, a series of 10 new naphthalene-chalcone derivatives were synthesized and their anticancer-antibacterial-antifungal properties were investigated. Among the compounds, compound 2j showed activity against the A549 cell line with an IC50 = 7.835 ± 0.598 µM. This compound also has antibacterial and antifungal activity. The apoptotic potential of the compound was measured by flow cytometry and showed apoptotic activity of 14.230%. The compound also showed 58.870% mitochondrial membrane potential. Compound 2j inhibited VEGFR-2 enzyme with IC50 = 0.098 ± 0.005 µM. Molecular docking studies of the compounds were carried out by in silico methods against VEGFR-2 and caspase-3 enzymes.