Synthesis, characterization and biological screening of some Schiff base macrocyclic ligand based transition metal complexes as antifungal agents

As part of a continuing search for the synthesis of new antimicrobial agents some macrocyclic tetradentate nitrogen donor (N4) ligand based transition metal complexes of the type [M(C12H20O8N4)Cl2] where M = Cu(II), Ni(II) and Co(II) were of our interest. All the compounds were synthesized and evaluated in vitro for their anticandidal property by performing minimum inhibitory concentration (MIC) along with ergosterol composition assay against Candida albicans ATCC 10261, Candida glabrata ATCC 90030, and Candida tropicalis ATCC 750, respectively. Results obtained indicate that growth and ergosterol content decreased significantly in the presence of the test compounds. All the synthesized compounds under investigation were also tested for toxicity by MTT assay on H9c2 cardiac myoblasts and the results showed that these compounds and the ligand offered remarkable viability in the range of 87–94% at a concentration of 25 μM. Ni(II) complex (KNi) was found to be the most active and least cytotoxic among all the compounds screened