Antimicrobial activity of a new series of benzimidazole derivatives

Due to antimicrobial importance of benzimidazoles and hydrazones, some benzimidazolehydrazone compounds were synthesized to screen their antimicrobial activity. Structures of the synthesized compounds were elucidated by 1H-NMR, IR and ES-MS spectral data and elemental analysis. The synthesized benzimidazole-hydrazones exhibited very weak antibacterial activity. However, antifungal activity of some of the synthesized compounds was very notable against Candida species. The compounds displaying important antifungal activity were screened for their toxicity. Artemia salina 96-well assay was used to determine cytotoxicity of the compounds. Tested compounds exhibited toxicity to different extents (LD50 = 126.33−368.72 μg/mL). Nevertheless, determination of 3–14 folds higher LD50 than minimum inhibitory concentration is a significant finding, which demonstrates that the compounds display antifungal activity at non-toxic concentration.