Antibacterial activities of sulfamethoxazolyl-azo-phenols and their Cu(II) complexes along with molecular docking...

Sulfamethoxazolyl-azo-phenols [SMX-N=N-C₆H₂(R)(R^/)-OH] (1a, 2a) and their Cu(II) complexes, [Cu(SMX-N=N-C₆H₂(R)(R^/)-O)₂] (1b, 2b) (R = p-OMe, R^/ = H, 1a/1b; R = p-Cl, R^/ = m-CH₃, 2a/2b) show antibacterial sensitivity against Gram-positive bacteria, B. subtillis; IC₅₀: 281.47 ± 1.84 μM (1a), 126.39 ± 1.66 μM (1b), and 279.94 ± 3.15 μM (2a), 123.62 ± 1.27 μM(2b), and Gram-negative bacteria, E. coli; IC₅₀: 204.66 ± 3.31 μM (1a) and 89.05 ± 1.48 μM (1b), 223.13 ± 2.71 μM (2a), and 98.26 ± 1.59 μM (2b). Interaction of DNA with free ligand (1a and 2a) is insignificant, while the complexes (1b and 2b) interact strongly and the binding constants are K _b, 8.413 × 10⁴ M^-1 (1b) and 6.56 × 10⁵ M^-1 (2b). Optimized structures of the compounds are docked with protein structure of DHPS (E. coli) to propose the most favoured binding mode of the drugs in the active site. The in silico test of the compound helps to understand drug metabolism, drug-protein interactions, and toxicity (ADMET).