Novel benzimidazole derived naphthalimide triazoles： synthesis, antimicrobial activity and interactions with calf thymus DNA

• Published in: Science China. Chemistry 2015-03, Vol.58 (3), p.483-494
• Main Authors: Luo, Yun-Lei, Baathulaa, Kishore, Kannekanti, Vijaya Kumar, Zhou, Cheng-He, Cai, Gui-Xin
• Format: Article
• Language: English
• Subjects: Antimicrobial agents; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Dilution; Fungicides; NMR; Norfloxacin; Nuclear magnetic resonance; Thymus gland; Triazoles; 三唑; 合成; 小牛胸腺DNA; 抗菌活性; 新化合物; 苯并咪唑; 衍生; 金黄色葡萄球菌
• ISSN: 1674-7291; 1869-1870
• DOI: 10.1007/s11426-014-5296-3

A novel series of benzimidazole derived naphthalimide triazoles and some corresponding triazoliums have been successfully synthesized and characterized by 1H NMR, 13 C NMR, 1H-1H COSY, IR and HRMS spectra. All the new compounds were screened for their antimicrobial activities in vitro by two-fold serial dilution. 2-Chlorobenzyl triazolium 8g and compound 9b with octyl group exhibited the best antibacterial activities among all the tested compounds, especially against S. aureus with inhibitory concentration of 2 μg/mL which was equipotent potency to Norfloxacin（MIC=2 μg/mL） and more active than Chloromycin（MIC=7 μg/mL）. Triazoliums 8g and 8f bearing 3-fluorobenzyl moiety displayed the best antifungal activities（MIC=2-19 μg/mL） against all the tested fungal strains without being toxic to PC12 cell line within concentration of 128 μg/m L. Further investigations by fluorescence and UV-Vis spectroscopic methods revealed that the compound 8g could effectively intercalate into calf thymus DNA to form the 8g-DNA complex which could block DNA replication, exerting powerful antimicrobial activities.