Circular Dichroism Studies of Metal Complexes of Chiral Antibiotics in Solution

摘要

Circular dichroism (CD) studies have been utilized to investigate complexationability of chiral antibiotics, Sodium (+)-benzylpenicillinate and (+)-tetracycline with transition metal ions like VO(II), Cr(III), Co(II) and Cu(II) in alcohol-water (70:30) or in aqueous solutions. The two chiral drugs and metal ions (due to their achiral nature) have no CD bands in the visible region. When metal ions and ligand solutions were mixed, complexation was indicated with the development of well defined, fairly strong CD bands in the crystal field region. The conditions of pH, stoichiometery and time for achieving equilibrium was determined for maximum complexation in these systems. The absorption and CD spectra of these systems maintained under optimum conditions of pH, stoichiometery, concentration and time were measured and interpreted in term of electronic transitions.