Simultaneous high-performance liquid chromatographic determination of sennoside A metabolites in rat and mouse feces

Abstract

A method for high-performance liquid chromatography (HPLC) has been established for the simultaneous determination of rheinanthrone, sennidin A, sennidin B and rhein formed by incubation of sennoside A with rat and mouse feces. The analysis was done within 20 min with a Wakosil-II5C18HG column by linear gradient elution using a mobile phase containing aqueous phosphoric acid and acetonitrile. Rheinanthrone was unstable in solutions when exposed to air. As for the stability in the solvents, rheinanthrone in ethyl acetate was relatively resistant to degradation at room temperature, and ethyl acetate was suitable as a solvent extracted from the incubation mixture. Ethyl acetate extract improved the stability of rheinanthrone following dehydration treatment with magnesium sulfate. This method is applicable to determine metabolites of sennosides by anaerobic incubation with rat and mouse feces.