Abstract

After intravenous dosage in dogs, the major portion of the xanthine oxidase inhibitor, 3-(4-pyrimidinyl)-5-(4-pynidyl)-1,2,4-triazole, is excreted in bile as a polar conjugate refractory to µ-glucuronidase, sulfatase, µ-glycosidase and nucleoside phosphorylase. High resolution mass spectrometry. nuclear magnetic resonance, absorption and fluorescence spectra, and identification of chemical hydrolysis produets of recrystallized conjugate have established its structure as the N-(1)-µ-D-glucopyranoside. The same conjugate is a sigificant component of renal and biliary elimination in the rat and monkey as well. These constitute the first reported instance of N-glucosylation as a detoxification mechanism in mammals.