Complexation of penicillins and penicilloic acids by cupric ion

Abstract

Abstract A kinetic method was developed to study the interactions between cupric ion and penicillins G and V. Complexation was found to occur with the intact penicillins, followed by rapid hydrolysis of the complex into the corresponding penicilloic acid-cupric ion complex. The logarithmic stability constants for the interaction between cupric ion and penicillins G and V were found to be 2·61 and 2·24, respectively. In addition, the method of continuous variation was used to determine the logarithmic stability constants for the cupric ion-penicilloic acid complexes. These were found to be 4·20 and 4·50, for penicilloic V and G acids respectively.