Preparation, spectral characterization and biological applications of Schiff base ligand and its transition metal complexes

Abstract

The present work deals with the study of chemical synthesis of Schiff base ligand, (L) derived from 5-amino-4H-1,2,4-triazole-3-thiol and 3-hydroxy-4-methoxy benzaldehyde and its Cu(II), Co(II), Mn(II), Zn(II) and Ni(II) complexes in 2:1 stoichiometric ratio (2L:M). The structures of all the synthesized compounds were analyzed using FTIR, UV–Visible, MS, 1H NMR, 13C NMR and thermo gravimetric methods. Further, the ligand (L) and its metal complexes were screened for in vitro antibacterial activity against nine food pathogens and their potential activity were qualitatively and quantitatively assessed by the presence/absence for zone of inhibition and minimum inhibitory concentration (MIC) values. The standard antibiotic drug amoxicillin was used as positive control. Impregnated paper discs containing only DMSO used as negative control did not show zone of inhibition. The free radical scavenging ability of test samples were assessed by employing a series of in vitro assays viz., DPPH, ABTS and Superoxide, where Butylated hydroxyl anisole (BHA) was used as a positive control. We have also tested in vitro Inhibitory effects on yeast α-glucosidase and α-amylase using acarbose as a positive control.

Keywords

• Triazole-based ligand
• Transition metal complexes
• NMR
• Pathogens
• Antioxidant assay
• Inhibitory effects