Quantitative measurement of demethylation of 14C-methoxyl labeled DMPEA and TMA-2 in rats.

Some reports have suggested that methylation and demethylation of compounds related to 6-hydroxydopamine may be involved in endogenous mental disorder. We report the synthesis of 3,4-dimethoxyphenethylamine (DMPEA) and 2,4,5-trimethoxyphenylisopropylamine (TMA-2) with each methoxyl group separately labeled with 14C. The rate and percent demethylation of these two compounds, with five labeled positions, were determined in the rat. The results suggest that TMA-2 might be metabolized to a hydroquinone in vivo; a similar metabolic intermediate of the psychoactive compound DOM is known to give rise in vitro to an indole.