Excretory Profile of 4-Bromo-2,5-dimethoxy-phenethylamine (2C-B) in Rat

The urinary and faecal metabolic profiles of 4bromo-2,5-dimethoxyphenethylamine (2C-B) in rat were investigated. Male Wistar rats were administrated 10 mg/kg of 2C-B hydrochloride orally, and the urine and faeces were collected 0‐24 and 24‐48 hr after administration. The samples were processed by liquidliquid extraction, and the extracts analyzed by GC/ MS, after derivatization. The major metabolite excreted into the urine was 5-O-desmethyl-N-acetyl-2CB, comprising 13.2% of the administrated dose. Other metabolites detected in the urinary extracts were 2-Odesmethyl-N-acetyl-2C-B (5.8%), 2-O-desmethyl-2CB (3.5%), carboxylic acid compound (1.9%), 5-Odesmethyl-2C-B (1.2%) and an alcoholic compound (0.8%). Only 0.2% of the administrated 2C-B was excreted into the urine in its original form. On the other hand, only 5-O-desmethyl-N-acetyl-2C-B and 2-Odesmethyl-N-acetyl-2C-B were detected in the faecal extracts. The major fraction of the urinary metabolites that contained a hydroxy group were recovered as conjugates.