Metabolism of clebopride in vitro Identification of N-oxidized products

1. N-(1′-Benzyl-4′-piperidyl-N-oxide)-4-amino-5-chloro-2-methoxybenzamide,N-(4′-(N-hydroxylpiperidyl))-4-amino-5-chloro-2-methoxybenzamide and N-(4′-(Δ1′-piperidyl-N-oxide))-4-amino-5-chloro-2-methoxybenzamide were obtained from chloro- form extracts of incubation mixtures of clebopride or desbenzyl clebopride with 9000g supernatant of liver homogenates of male NZW rabbits.

2. These metabolites were identified using electron impact (low and high resolution) and field desorption mass spectrometry, and computer averaged time proton magnetic resonance spectroscopy.