Homo- and heterometallic coordinative compounds of Cu(II) and Bi(III) with aminopolycarboxylates and 2-benzoylpyridine thiosemicarbazones

Abstract

This article deals with the synthesis and study of three homometallic coordination compounds of Cu(II) and four Cu(II) - Bi(III) heterometallic compounds with mixed polydentate ligands, thiosemicarbazone - aminopolycarboxylate (APC), with the general formulas Cu(L)2Cu(APC)·nH2O, Cu(HL){Bi(APC)}2·nH2O and Cu(L)Bi(APC)·nH2O (n = 0 - 13, APC = edta4- and cdta4-), 4-methyl- and 4-ethyl-thiosemicarbazones of 2-benzoylpyridine are in the monodeprotonated (L) or nondeprotonated (HL) forms. The antibacterial activity of heterometallic compounds Cu(HBzPyTSC-4Me){Bi(edta)} 2 (4) and Cu(HBzPyTSC-4Et){Bi(edta)}2·7H2O (6) was determined against Gram-positive strains Staphylococcus aureus (ATCC 25923) and Bacillus cereus (ATCC 11778) and two Gram-negative strains Escherihia coli (ATCC 25922) and Acinetobacter baumannii (BAA- 747). The compounds displayed high activity against Staphylococcus aureus (ATCC 25923), with the minimum inhibitory concentration MIC = 0.24 μg/mL, a value approximately 19 times higher than the activity of Furacilin (4.67 μg/mL). Both compounds have bactericidal activity against Bacillus cereus strain (ATCC 11778) with MIC = 0.97 μg/mL, which is about 4.8 times higher than the activity of Furacilin. The fungicidal activity of the compounds 4 and 6 against Candida albicans strain, expressed in MIC, was found to be 7.81 and 15.62 μg/mL, correspondingly, values of about 4 and 2 times higher than the one of Nystatin (32.0 μg/mL).