Hydrolysis of 2'-esters of erythromycin

Abstract

Hydrolysis rates were determined for 2′-acetyl erythromycin, three of its homologues (2′-propionyl, 2′-butyryl and 2′-valeryl) and 2′-ethylsuccinyl erythromycin in buffer solution (pH 7·0, 37°C) and in human plasma (37°C at concentrations of 5 and 100 mg/l. Ester concentrations were measured by fast atom bombardment mass spectrometry. Hydrolysis in buffer followed pseudo first-order kinetics. The half-lives of the esters ranged from 24.3 to 89.5 min (2′-ethyl-succinyl 1 -acid gtycoprotein. Of the homologous esters, 2′-acetyl erythromycin was hydrolysed most rapidly, but it was hydrolysed more slowly than 2′-ethylsuccinyl erythromycin.