SYNTHESIS AND EVALUATION OF A COUMARIN SCHIFF-BASE FOR IN VITRO ANTIBACTERIAL ACTIVITY AGAINST STAPHYLOCOCCUS AUREUS

Objective: 44 novel Schiff bases of aminated 4-methylumbelliferones were designed and subjected to in silico evaluation of activity against S. aureus, with Dihydrofolate Reductase (DHFR) as the target. The top-scoring compounds (as per binding affinities) were subjected to drug-likeness and ADMET evaluation. Overall assessment of the binding affinities, drug-likeness and ADMET profile (especially toxicity) suggested that the derivative, BVSSS22 was found to be the most promising Schiff base (even when compared to the standard, Trimethoprim). Hence, the objective was to synthesize BVSSS22 and evaluate it for in vitro activity against S. aureus. Methods: BVSSS22 was synthesized, characterized via melting point, TLC, and spectral data acquisition (ATR-IR, NMR, and HRMS), and evaluated for in vitro antibacterial activity against S. aureus using the agar-well diffusion method, with Trimethoprim as the standard (n=3). Results: BVSSS22 was successfully characterized, and the in vitro antibacterial assay showed that BVSSS22 possessed zones of inhibition, where at 400 µg/ml, the zone of inhibition was slightly less than that of trimethoprim (18.33±0.57 mm v/s 17.33±1.15 mm). Conclusion: The results show that BVSSS22 is a potent and safe drug candidate for anti-S. aureus action. However, it can be evaluated at a concentration higher than 400 µg/ml or undergo further structural optimization to enhance its in vitro potency to surpass that of Trimethoprim.