SYNTHESIS, EVALUATION AND POLYMORPHISM STUDIES OF NEW BENZIMIDAZOLE DERIVATIVES AS POTENT ANTIBACTERIAL AGENTSAbstract
Ten, 2-substituted benzimidazole derivatives were prepared and assessed against two Gram-positive bacteria (Streptococcus mutans, Staphylococcus aureus) and two Gram-negative bacteria (Psuedomonas aeruginosa, Escherichia coli). The derivatives were obtained by the condensation of 2-((1H-benzo[d] imidazol-2-yl) thio) acetohydrazide(4) with different substituted aromatic aldehydes and their structures were characterized by FTIR, 1H NMR. The compound (E)-2-((1H– benzo [d] imidazole-2-yl) thio)- N´- (furan- 2- yl- methylene) acetohydrazide (6g) showed potent activity against both Gram-positive species (0.2-0.8 µg/ml of MIC) which was better than the standard drug Ciprofloxacin. The derivative (E)-2-((1H-benzo[d]imidazole-2-yl) thio)-N´-(4-methoxybenzylidene) acetohydrazide (6a) was evaluated for potential polymorphism by differential scanning calorimetry (DSC). It was then subjected to crystallization using different solvents. The crystal obtained from acetonitrile solvent displayed different thermal transition (240.82 °C) from that of the parent crystal (234.52 °C).
K. L. S. Konyak, M. M. Maste, A. Saxena * and P. Inamdar
Department of Pharmaceutical Chemistry, KLE University College of Pharmacy Belagavi, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India.
26 July, 2017
12 October, 2017
20 October, 2017
01 May, 2018