Microwave-assisted synthesis, spectral characterization, and biological activities of complexes of a Schiff base derived from S-benzyl dithiocarbazate

Co(II), Ni(II), Zn(II), and Cd(II) complexes were synthesized from a Schiff base ligand, benzyl-2-(1-(thiophen-2-yl)propylidene)hydrazine-1-carbodithioate (BTPHC), by conventional as well as microwave irradiation methods. The ligand and its metal complexes were characterized by spectroscopic techniques (FT-IR, UV-vis, mass spectrometry, and 1H NMR) and powder X-ray diffraction. Based on magnetic measurements and spectral data, octahedral environments for Co(II) and Ni(II) complexes and tetrahedral environments for Zn(II) and Cd(II) complexes are proposed. The metal(II) complexes were active toward bacterial and fungal strains. Antidiabetic studies showed that the Cd(II) complex possesses greater potential as an antidiabetic agent than the other metal complexes and the ligand. Antioxidant studies indicate that the Zn(II) and Cd(II) complexes possess high radical scavenging activities. The synthesized ligand and metal(II) complexes were screened for their anticancer properties against two human cancer cell lines MCF-7 and HeLa using an MTT cell viability assay. The Ni(II) complex excelled in halting the proliferation of HeLa and MCF-7 cancer cell lines with IC50 values of 46.63 µM and 80.90 µM, respectively, whereas it displayed insignificant cytotoxicity against the human normal embryonic kidney cell line (HEK293) with IC50 = 300.41 µM.