Benzofurano-isatins: Search for antimicrobial agents

In an attempt to find a new class of antimicrobial agents, a series of novel N′-(5 or 7 substituted-2-oxoindolin-3-ylidene)benzofuran-2-carbohydrazides 3(a-p) were synthesized by reacting benzofuran-2-carbohydrazide 1 with 5 and 7 substituted-isatins 2(a-p). The synthesized compounds were confirmed by melting point, IR, 1H NMR, 13C NMR and mass spectroscopy. All the synthesized compounds were screened for antimicrobial activity among the tested series, 3o exhibited excellent antibacterial activity against Escherichia coli and Pseudomonas vulgaris while 3p against Bacillus subtilis, E. coli and P. vulgaris (31.25 μg/mL) when compared with standards. Similarly 3o and 3p showed significant antifungal activity (31.25 μg/mL) when compared to fluconazole against Aspergillus niger.