Spectroscopic characterization, antimicrobial activity and molecular docking study of novel azo-imine functionalized sulphamethoxazoles

Abstract

[SMX—N=N—C6H3—(p-OH)(m—CHO)] ( 1 ) reacts with ArNH2 to synthesize Schiff bases, [SMX—N=N—C6H3—(pOH)(m—HC=N—Ar)] (Ar =—C6H5 ( 2a ), —C6H4—p—CH3 ( 2b ), —C6H4—p—OCH3 ( 2c ), —C6H4—p—Cl ( 2d ), —C6H4—p—NO2 ( 2e ), —C10H7 ( 2f )) and the products have been assessed for antibacterial properties against Gram positive bacteria, B. subtillis: IC50 (μg/ml): 39.2 ( 1 ), 60.1 ( 2a ), 64.0 ( 2b ), 85.6 ( 2c ), 55.1 ( 2d ), 88.4 ( 2e ) and 65.1 ( 2f ); and Gram negative bacteria, E. coli: IC50 (μg/ml): 159.0 ( 1 ), 151.4 ( 2a ), 155.3 ( 2b ), 140 ( 2c ), 156.0 ( 2d ), 153.5 ( 2e ) and 157 ( 2f ). The cell line toxicity (Vero cells) has also been evaluated with these compounds and EC50 (μg/ml) values are 129.9 ( 1 ), 74.2 ( 2a ) and 93.0 ( 2b ), 191.9 ( 2c ), 99.1 ( 2d ), 93.2 ( 2e ) and 62.0 ( 2f ). The anti-viral efficiency against harpies virus (HSV1F ATCC-733) infection demonstrates that the compound 1 has highest selectivity index (CC50/EC50), 5.06 than the compounds 2a-f (CC50/EC50: 1.18 ( 2a ), 1.42 ( 2b ), 3.50 ( 2c ), 1.45 ( 2d ), 1.58 ( 2e ), 1.29 ( 2f )). The compounds have been spectroscopically characterized and the structural confirmation has been established in one case by single crystal X-ray diffraction studies of 2c . In silico Molecular Docking study has been done using optimized geometries of the compounds to search the most favored binding mode of these drugs and hence useful to explain their competitive drug efficiency.