Biological evaluation of potent antioxidant, lipoxygenase inhibitor and antibacterial: A comparative study

Three biologically active new Schiff bases, 2-[(3-hydroxybenzylidene)amino]phenol 5, 2-[(4-hydroxybenzylidene)amino]phenol 6 and 4-[(2-hydroxyphenylimino)methyl]benzene-1,3-diol 7, were synthesized by the reaction of 2-aminophenol 1 with three different hydroxyl-benzaldehydes 2–4. They were characterized by spectroscopic analysis (IR, 1H NMR, EI-MS) along with elemental analyses. The products were biological screened out for antioxidant, lipoxygenase inhibition, antibacterial and urease inhibition activities. The compounds 5 and 6 showed potent while 7 showed moderate antioxidant activity. Compound 6 showed potent whereas 5 and 7 showed significant lipoxygenase inhibition activity. All the target compounds showed excellent activities against Staphylococcus intermedius, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Salmonella typhi bacteria. All the compounds showed non-significant activity against urease enzyme.