NMR Study of Spontaneous Degradation of Penicillin G in Aqueous Solution

The spontaneous degradation of penicillin G in aqueous solution has been studied using NMR and thin layer chromatography. Correlation NMR spectroscopy was used to follow products which appear at the early stage of degradation. It has been found that in 0.3 M phosphate buffer (pH 7.0, 30 °C) a successive first order degradation penicillin G 1 penicilloic acid 2 secondary product is dominant with kinetic constants of k1=0.7×10−2 h−1 and k2=6×10−2 h−1.