Evaluation of optimized molecular structure-antimicrobial and antioxidant efficacy relationship of Schiff bases

The synthesis, reactivity, structure, antimicrobial potential, and antioxidant property of some Schiff bases were extensively studied experimentally and theoretically using the B₃LYP method of DFT (density functional theory). Schiff bases formed with the interaction of salicylaldehyde and amino alcohols in a 1:1 molar ratio in ethanol. The physicochemical and spectroscopic investigations decide the plausible structure of these newly synthesized Schiff bases. The computational study can assess the molecular orbitals, chemical reactivity, stability, and molecular electrostatic potential of Schiff bases. The thermodynamic parameters and optimized structures of Schiff bases in the gaseous state investigated by the B₃LYP method of DFT. The evaluation of Schiff bases possesses antimicrobial resistance against gram-negative (Pseudomonas aeruginosa) and (Bacillus cereus)gram-positive bacterial strains as well as fungal strains (Candida albicans and Penicillium chrysogeum). The MIC (minimum inhibitory concentration) of all Schiff bases against Bacillus cereus was found in the range of 250 to 1200 µg. The MIC values of L₁H, L₂H, and L₃H against Penicillium chrysogeum were 400, 600, and 800 µg, respectively, whereas the MIC value of L₁H against Candida albicans was 600 µg. The free radical scavenging activity by the DPPH method was used to access potential antioxidant activity in Schiff bases.