Synthesis, antimicrobial and antioxidant evaluation with in silico studies of new thiazole Schiff base derivatives

Abstract

A series of nineteen thiazole Schiff base derivatives 2a-2s were synthesized (Scheme 1) and elucidated by spectral analyses (IR, 1H NMR and HRMS). The evaluation of their antimicrobial activities against two gram-positive, two gram-negative, and two fungal strains revealed that some compounds displayed moderate antimicrobial activities compared to standard ciprofloxacin and miconazole in disc diffusion technique. Compound 2a displayed very strong antioxidant efficacy (IC50 = 3.52 ± 0.86 µg/mL) compared to standard ascorbic acid (IC50 = 27.34 ± 1.86 µg/mL) in DPPH free radical scavenging assay. Compounds 2j, 2k, and 2m displayed significant antioxidant activities in this assay as well. In silico analysis predicted that the synthesized compounds follow the Lipinski's rule of five and Veber's rule with one exception. The compounds displayed good drug-likeness and drug-score properties. The molecular docking studies predicted that the synthesized thiazole Schiff base derivatives are tolerable in putative receptor binding sites.