Identification of Four New Metabolic Products of Metoclopramide using Mass Spectrometry

Abstract

1. N-(Diethylaminoethyl)-4-amino-5-chloro-2-methoxybenzamide (metoclo-pramide, I), N-(ethylaminoethyl)-4-amino-5-chloro-2-methoxybenzamide (II), N-(aminoethyl)-4-amino-5-chloro-2-methoxybenzamide (III), N-(2′-hydroxy-ethyl)-4-amino-5-chloro-2-methoxybenzamide (IV), N-(diethylaminoethyl)-4-amino-5-chloro-2-hydroxybenzamide (V), and N-(ethylaminoethyl)-4-amino-5-chloro-2-hydroxybenzamide (VI) were obtained from chloroform extracts of incubation mixtures of I or II (HC1 salts) with 9000 g liver microsomal preparations from male rabbits.2. Mass spectrometry (electron impact, chemical ionization and high resolution) was used to identify low concentrations of these products.