In vivo metabolism of 4-bromo-2,5-dimethoxyphenethylamine (2C-B) in the rat: identification of urinary metabolites.

In rats, the psychoactive compound 2C-B is broken down into at least six distinct breakdown products through two main metabolic pathways. One pathway converts 2C-B into an aldehyde, which is then further processed into an alcohol and a carboxylic acid. The other pathway produces metabolites where a methyl group is removed from either the 2- or 5-position of the molecule, followed by acetylation of the amino group. These findings indicate that the body metabolizes 2C-B through multiple chemical changes, resulting in a variety of metabolites that are excreted in urine.

Study at a glance

Abstract

The in vivo metabolism of 4-bromo-2,5-dimethoxyphenethylamine (2C-B), a ring-substituted psychoactive phenethylamine, in the rat was studied. Male Wistar rats were administered 10 mg/kg of 2C-B hydrochloride orally, and 24 h urine fractions were collected. After enzymatic hydrolysis of the urine samples, the metabolites were extracted by liquid-liquid extraction and analyzed by gas chromatography-mass spectrometry. 2-(4-Bromo-2,5-dimethoxyphenyl)-ethanol, 4-bromo-2,5-dimethoxyphenylacetic acid, 2-(2-hydroxy-4-bromo-5-methoxyphenyl)-ethylamine, 2-(2-methoxy-4-bromo-5-hydroxyphenyl)-ethylamine, 1-acetoamino-2-(2-hydroxy-4-bromo-5-methoxyphenyl)-ethane, and 1-acetoamino-2-(2-methoxy-4-bromo-5-hydroxyphenyl)-ethane were identified as 2C-B metabolites. These findings suggest that at least two metabolic pathways for 2C-B are operative in rats. The first pathway leads to the corresponding aldehyde metabolite by deamination, which is subsequently reduced or oxidized, to give the corresponding alcohol and carboxylic acid metabolites. The second pathway leads to the corresponding 2-O-desmethyl or 5-O-desmethyl metabolites in which the amino group is subsequently acetylated.