Antimalarial and Antimicrobial Activities of some Heteroleptic Metal(II) Complexes of Sulfadiazine–Vitamin C: Synthesis and Spectroscopic Studies

Some new Ni(II), Zn(II), Co(II), Cu(II), and Cd(II) of mixed Sulphadiazine and Vitamin C complexes have been synthesized and characterized by different spectroscopic techniques such as FT-IR, elemental analysis, molar conductivity, and magnetic measurements. Both ligands used for this research work act as bidentate ligands towards the central metal ions coordinating through the nitrogen atoms of >C=N-, NH2 groups of Sulphadiazine and oxygen atoms of OH, CO groups of Vitamin C. Tetrahedral and square-planar geometries have been proposed for the complexes. The complexes are stable under atmospheric conditions. The ligands and their complexes were screened for antimicrobial activities against some isolated organisms: Klebsiella pneumoniae, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis to evaluate their microbial inhibiting potential. The derived complexes were found to exhibit an increased inhibitory action against the organisms when compared to the free ligands. The percentage reduction in parasitaemia for the compounds was also evaluated against Plasmodium berghei. In this realm, [Cd(Su)(Vit)]Cl2 showed the highest activity (89%) as compared to other compounds: Sulphadiazine, Ni(II), Zn(II), Co(II), and Cu(II) complexes are 70, 50, 81, 76, and 77%, respectively, Vitamin C showed no activity. Keywords: Sulfadiazine, Antimalarial, Vitamin C, Physicochemical, Metal-drug complexes, Antimicrobial