A New Metabolic Pathway of Bromazepam Involving Attachment of a Methylthio Group

Abstract

1. The structures of three hitherto unidentified metabolites of bromazepam in the rat were elucidated using u.v., mass, n.m.r. and i.r. spectrometry.

2. All three metabolites contained a methylthio or corresponding oxidized group at the C-6′ position of the pyridyl moiety.

3. Quantitative analysis of the metabolites determined after administration of [¹⁴C]bromazepam to rat revealed that the three metabolites together comprised about 6 % of the total radioactivity excreted in the 24-h urine, or about 1 % of the dose.