The Relationship of Metal Binding to the Biological Activities of Phenethylbiguanide*

Abstract

Phenethylbiguanide has been found to form metal complexes with divalent copper and nickel; on the basis of infrared absorption spectra and on theoretical considerations, a revised structure for the metal complexes of biguanides is proposed. Antimicrobial activities of phenethylbiguanide are not affected by divalent copper and nickel but are significantly depressed by iron. The relationship of these findings to the biological mechanisms of action of the compound is discussed.