Synthesis, characterisation, and antimicrobial activities ofS-Benzyl-β-N-3-methoxybenzoyl Dithiocarbazate (SB3OME)and its metal complexes

A new substituted dithiocarbazate derivative ligand, S-benzyl-β-N-3-methoxybenzoyl dithiocarbazate (SB3OME) has been prepared via the nucleophilic substitution reaction of S-benzyldithiocarbazate with meta-methoxybenzoyl chloride. A series of complexes of SB3OME with Cu(II), Zn(II), Co(II), and Ni(II) were also synthesised. These complexes have a general formula of [M(SB3OME)2], where M represents Cu2+, Zn2+, Co2+, and Ni2+. All the synthesised compounds were characterised using various physico-chemical techniques. It was found that all complexes exhibited a six-coordinate where SB3OME acts as a uninegatively charged tridentate NOS ligand, resulting in an octahedral geometry. The antimicrobial activities of all compounds against Staphylococcus aureus (ATCC 25923), Bacillus cereus (ATCC 11778), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922) were evaluated. The values of minimum inhibitory concentration (MIC) were obtained in reference to gentamycin as the standard drug. MIC assay shows that Cu(SB3OME)2 is the most active compound with a MIC value of 437 ug/ml against Staphylococcus aureus (ATCC 25923) and Pseudomonas aeruginosa (ATCC 27853). This study concludes that the antimicrobial activities will enhance upon coordination with metal ions, and the metal complexes can be considered for further development as potential antibiotics.