Thin-layer chromatographic study of the metabolites of erythromycins in the wistar rat

Abstract

The metabolites of erythromycin A, anhydroerythromycin A, N-demethylerythromycin A and erythromycin B in the Wistar rat were studied by thin-layer chromatography. In some experiments germ-free rats, rats with a cannulated bile duct and a gastrectomized rat were used. The erythromy¬cins examined were shown to undergo two principal changes, N -demethylation and acid-catalysed degradation. It was demonstrated that the stomach and the liver are not the sole sites of acid degra¬dation and demethylation of erythromycins, respectively. Erythromycin A give, three principal me¬tabolites, anhydroerythromyein A, anhydro-N -demethylerythromycin A and N -demethylerythromycin A, and erythromycin A enol ether and N-demethylerythromycin A enol ether are present to a minor extent. 5-0-Desosaminyleryt:-.ronolide A was also identified, suggesting the presence of an erythro¬mycin glycosidase.