Heterobimetallic complexes containing organometallic acylhydrazone ligands as potential inhibitors of human carbonic anhydrases

In the search of new bioorganometallic compounds as potential inhibitors of human (h) carbonic anhydrases (hCAs, EC 4.2.1.1), heterobinuclear ruthenium(II) complexes based on organometallic-acylhydrazones have been obtained. The complexes (1a-b, 2a-b) were prepared by reaction between the corresponding organometallic-acylhydrazone of the general formula [{(η5-C5H4)CH=N-NH-C(O)-C6H4–4-SO2NH2}]MLn or [{(η5-C5H4)CH=N-NH-C(O)-CH2CH2-NH-C6H4–4-SO2NH2}]MLn (where MLn = Re(CO)3; FeCp) and [Ru(p-cymene)Cl2]2. All compounds were characterized by conventional spectroscopic techniques and cyclic voltammetry. Biological evaluation as CA inhibitors (CAIs) was carried out and showed derivatives 1a, 2a and 2b to behave as selective inhibition against the tumors associate isoforms hCA IX and XII making them interesting candidates for preclinical evaluation in various hypoxic tumors in which the two enzymes are overexpressed.