SYNTHESIS, ANTIBACTERIAL EVALUATION AND DOCKING STUDIES OF SOME NOVEL ISATIN DERIVATIVES

Benzylimino isatin Mannich bases (IS1 & IM1-IM6) were designed manually and synthesized by the simple Mannich reaction. The synthesized compounds were confirmed by means of their spectral evidence (FTIR, 1H NMR and ESI-MS). The antibacterial activities were carried out with Gram +ve as well as Gram -ve bacteria by disc diffusion method. All the compounds showed moderate In vitro antibacterial activity, particularly, compound IM4 (E)-3-(benzylimino)-1-[(4-methylpiperazin-1-yl)methyl]indolin-2 -one showed better activity with 19, 17, 17 and 11 mm zone of inhibition at 100 μg/0.1 mL concentration against Gram +ve bacteria (S. aureus, B. subtilis) and Gram –ve bacteria (P. eruginosa, E. coli) respectively compared to standard fluoroquinolone antibacterial ciprofloxacin, which have 30 mm zone of inhibition at 10 μg/0.1 mL concentration in Gram +ve bacteria (B. Subtilus) as well as Gram -ve bacteria (P. eruginosa). Molecular docking studies were carried out for active compound IM4 with DNA gyrase enzyme (1kzn) protein by Molegro Virtual Docker 2013.1.6 (MVD), in order to determine the probable binding model in to active site of 1kzn with the compound IM4.