Synthesis, in vitro and in silico studies of some novel 5-nitrofuran-2-yl hydrazones as antimicrobial and antitubercular agents

抄録

In this study, we synthesized two series of novel 5-nitrofuran-2-carbohydrazides 21a-h and 22a-e in addition to a third series of thiophene-2-carbohydrazides 23a-g to develop potent antimicrobial and/or antitubercular agents. The newly synthesized compounds were evaluated in vitro for their antimicrobial and antimycobacterial activities. Most of the 5-nitrofuran-2-carbohydrazides 21a-h and 22a-e displayed variable activity against Aspergillus fumigates, Staphylococcus aureus, Streptococcus pneumonia, Bacillis subtilis, Salmonella typhimurium, Klebsiella pneumonia, Escherichia coli and Mycobacterium tuberculosis. The sulfonamide derivative 21f exhibited superior potency and broad-spectrum antimicrobial activity with MIC = 0.06-0.98 µg/mL and antimycobacterial activity with MIC = 3.9 µg/mL. The 5-nitrofuran-2-carbohydrazides 21a, 21b, 21g, 21h and 22a-c exhibited significant antibacterial activity with MIC values in the range of 0.12-7.81 μg/mL. The significances of the 5-nitrofuran moiety and sulfonamide function were explored via the SAR study. In addition, docking studies revealed that the p-amino benzoic acid (PABA) and binding pockets of the dihydropteroate synthase (DHPS) were successfully occupied by compound 21f. Furthermore, two QSAR models were built to explore the structural requirements which controlled the activity.