Metabolism of ferulic acid in rats

Ferulic acid is the major active constituent in many natural Chinese medicinal herbs. The metabolism of ferulic acid has been investigated using solid-phase extraction and HPLC-DAD methods that were established to separate and analyze the metabolites in urine, feces and bile. Three metabolites, identified by enzymatic hydrolysis, HPLC-DAD, HPLC-MS and MS/MS, are all glucuronic acid conjugates of ferulic acid. Ferulic acid conjugated with one glucuronic acid at different positions produces M1 and M3. Ferulic acid conjugated with two glucuronic acids produces M2, which is the main metabolite. A metabolic pathway is proposed.