Synthesis, characterisation and antimicrobial activities of vic-dioxime derivatives containing heteroaromatic hydrazone groups and their metal complexes

Three novel heteroaromatic hydrazone derivatives bearing vic-dioxime groups (L1H2: 5-methyl-2-furfural hydrazone glyoxime, L2H2: 3-acetylpyridine hydrazone glyoxime and L3H2: 4-acetylpyridine hydrazone glyoxime) and their Ni(II), Cu(II) and Co(II) complexes were prepared. They were characterised by elemental analysis, gel permeation chromatography (GPC), FT-IR, UV, 1H NMR and 13C NMR. The antimicrobial activities of compounds L1H2, L2H2, L3H2 and their Ni(II), Cu(II) and Co(II) complexes were evaluated using the disc diffusion method against 13 bacteria and 5 yeasts. The minimal inhibitory concentrations (MICs) against 3 bacteria and 3 yeasts were also determined. Among the test compounds attempted, L1H2, [Co(L1H)2(H2O)2], [Ni(L2H)2], [Cu(L2H)2], L3H2, [Ni(L3H)2 and [Co(L3H)2(H2O)2] showed some activities against certain Gram-positive bacteria and some of the yeasts tested.