Absorption, distribution and metabolism of the anthelmintic methyridine

Possible Alternate Routes in the Metabolism of Betahistine in the Rabbit

“…N-2-Pyridylacetylglycine, previously reported as a metabolite of 2-(2-methoxyethyl) pyridine (9) , chromatographed essentially with the same Rf value (0.03, solvent K ) as 2-pyridylacetic acid, and the two consistently overlapped each other when chromatographed together on paper or silica gel. The Koenig reaction of 2-pyridylacetate pro- (X, 0.62, solvent K ) and ethyl N-2-pyridylacetylglycine accounted for 1.36% of the administered close.…”

“…The failure of an active dehydrogenase preparation to produce (9) 2-pyridylacetalde-hyde or 2-pyridylacetate from 2-(2-hydroxy ethy1)pyridine in vitro has been reported. Oxidation of 2-(2-hydroxyethy1)pyridine took place, however, and many additional pathways for the metabolism of betahistine and its congeners may be forecast from the studies.…”

“…From available data on the metabolism of betahistine and related compounds (8,9), it was considered (6) that demethylbetahistine (2-(2-aminoethy1)pyridine) and 2-(2-hy-droxyethy1)pyridine might both participate as intermediates in the metabolism of betahistine to 2-pyridylacetate. Preliminary experiments have shown (10) that the 12000 x g supernatant from rabbit liver is rich in ability to oxidize betahistine to 2-pyridylacetate.…”

“…packed with 3% SE-30 on 80-90 mesh Anakrom ABS; 50 ml/min helium carrier; injector at 200°, and detector at 210". N-2 -Pyridylacetylglycine was prepared by a modification of the method of Burns, Duncan and Scales (9). The ethyl ester was prepared by refluxing a mixture of 30 mg of N-2 -pyridylacetylglycine in 4 ml of absolute ethanol and 0.01 ml concentrated sulfuric acid for 16 hr.…”