Synthesis and Characterization of Two Cobalt Complexes of Tetracyclines

Abstract

The pleitropic properties of tetracyclines, the biological role of cobalt coupled with the improved biological activity of doxycycline upon chelation by metal ions as well as the biological importance of bipyridine and phenathroline have prompted us to synthesize cobalt-tetracycline complex and mixed ligand cobalt complex of doxycycline with dipyridine quinoxaline (dpq) as ancillary ligand. The two complexes were characterized by electronic, FT-IR and elemental analysis. In both complexes tetracycline, doxycycline and dpq behave as bidendate ligands, dpq coordinating via the two diimine nitrogen atoms. Detailed structural analysis of the complexes by FT- IR and UV-Vis are presented.