Abstract

DESIGN, SYNTHESIS, AND BIOLOGICAL ACTIVE STUDY OF NOVEL AMIDE-COUPLED 6-HYDROXY-N-PHENYL-9HCARBAZOLE- 3-CARBOXAMIDE PROMOTED BY COPPER HALIDE

P. Raja Sekhar Naidu, D. Radhika and N. Krishnarao*

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Abstract

The development of antimicrobials having a unique mode of action is an essential to solve problems of multi-drug resistance challenges. Here in, we have designed and synthesized novel amide-coupled 6- hydroxy-N-phenyl-9H-carbazole-3-carboxamide (6a-f) by acid-amine coupling reaction of 6-hydroxy-9H-carbazole-3-carbonyl chloride with substituted various amines in the presence of strong base. The synthesized amide-coupled naphthalene scaffolds were characterized through 1H NMR; 13C NMR, FT-IR as well as mass spectroscopic techniques. These derivatives were examined for their antimicrobial. Among all, “6d & 6e “exhibited excellent antibacterial activity at minimum inhibitory concentration (MIC) values ranging between 12.5 and 100 μg/mL against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcuspyogenes compared to standard drug Ciprafloxin. The antifungal assay revealed that compounds 6e wsa most effective (MIC - 250 μg/mL) against Candida albicans compared to standard drug Fluconazole.

Keywords: 6-hydroxy-9H-carbazole-3-carboxylic acid, 6-hydroxy-9H-carbazole-3- carbonyl chloride, 6-hydroxy-N-phenyl-9H-carbazole-3-carboxamide, Bioevluation.