Biotransformation of stobadine, a gamma-carboline antiarrhythmic and cardioprotective agent, in rat liver microsomes.

1. The metabolism of stobadine, a gamma-carboline antiarrhythmic and cardioprotective agent, was investigated in vitro using fortified rat liver microsomal preparations. 2. Two metabolic products, N-desmethyl stobadine and stobadine N-oxide were isolated and identified by means of t.l.c.,g.l.c. -mass spectrometry, n.m.r. spectrometry and comparison with synthetic reference compounds. 3. Stobadine N-oxide was resolved into two optically active stereoisomers which were produced enzymically in approximately equal quantities.