Antimicrobial investigation of novel multi-metal complexes of schiff base series

Schiff base had a promising application as an antibacterial agents as reported by previous studies but they are still in the discovery phase. Metal complexes with the Schiff base will increase the antibacterial properties theoretically. In the study, four samples were tested with two bacteria which were P. aeruginosa and B. subtilis. The samples were from hydrazide and isatin-derived Schiff base. There are two test conducted in the study which were minimum inhibitory concentration test and disk diffusion test. Minimum inhibitory concentration test was conducted to investigate the lowest concentration needed to inhibit the bacteria tested. Disk diffusion test was conducted to investigate the inhibition zone of the bacteria. The results obtained for the MIC test was sample 4 exhibit the best MIC value when tested against Gram positive bacteria. Sample 1 exhibit the best MIC value when tested against Gram negative bacteria. Meanwhile, the results obtained for disk diffusion test was only for sample 3 and sample 4 against B. subtilis. The rest of the samples showed no inhibition zone. Theoretically, the results of the disk diffusion test should be approximately the same with the minimum inhibition concentration in term of their critical concentration at the point of critical mass achieved. In the study, some error might affect the inhibition action of the samples or affect the growth of the bacteria. Sample 4 and 1 showed the convincing results to be developed as antibacterial agent in real life. However samples 4 can be improved in term of the medicinal chemistry to exhibit a better antibacterial action against Gram negative bacteria. Samples 1 which showed a moderate antibacterial action can be improved its activity by complexing it with the metal.