An in vitro antibacterial and antifungal effects of cadmium(II) complexes of hexamethyltetraazacyclotetradecadiene and isomers of its saturated analogue

Objective: To evaluate the antibacterial and antifungal effects of cadmium(II) complexes with hexamethyltetraazacyclotetradecadiene ligands. Methods: Five coordinated square pyramidal cadmium(II) complexes and six coordinated squaw octahedral cadmium(II) complexes have been synthesized by interaction of 5,7,7,12,14,14 hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene (denoted by L.2HClO(4)) and C-chiral isomers of its saturated analogue (denoted by 'teta' and 'tetb' with different salts of Cd2+ ion [e.g. CdI2, Cd(NO3)(2) center dot 6H(2)O, CdCl2 center dot 2H(2)O and Cd(ClO4)(2) center dot 6H(2)O] in methanolic solution. Complexes of the ligands were investigated for antibacterial activity by disc diffusion method and antifungal effect by poisoned food technique. Results: The newly synthesized cadmium(II) complexes of the ligands were screened as potential antimicrobial agent against a number of medically important bacteria (Staphylococcus aureus, Bacillus cereus Salmonella typhi Shigella dysenteriae and Escherichia and against two fungi (Candida albicans and Aspergillus aculeatus). The growth inhibiting activity of the ligands and complexes against bacteria and fungi were compared with the standard antibiotic ampicillin and commercially important antifungal agent, griseofulvin respectively. Among them some of the macrocyclic complexes were found to be more fungitoxic and antibacterial than the reference antifungal drug griseofulvin and antibacterial drug ampicillin respectively. Conclusions: Hexamethyltetraazacyclotetradecadiene ligands and its complexes could be considered as very potential antibacterial and antifungal agent with further investigation.