Synthesis, characterization and antimicrobial potential of transition metal complexes of triacetic lactone

Seven novel and biological active transition metal complexes were prepared using 3-nitro- 4-hydroxy -6-methyl-pyran-2-one derivative of triacetic lactone as ligand. These complexes were characterized by elemental analysis, magnetic susceptibility measurement, UV/Vis, FTIR and NMR spectroscopy. These data showed that solid complexes of Ni (II), Co (II), Mn (II), Zn (II) and Fe (II) indicated octahedral geometries while Cu (II) complex was assigned square planar geometry. The antimicrobial activities of all above mentioned complexes along with ligand were tested against eleven different bacterial strains and ten fungal strains using agar well diffusion assay. Cu (II) complex showed highest inhibition zone against Shigella dysentriae (22.3 mm), greater than standard drug, while the Zn (II) complex showed maximum antifungal activity against Trichophyton simii (18.7 mm). The antimicrobial activities indicated that metal complexes showed enhanced activity as compared to the free ligand.