Simultaneous determination mouse feces

A method fbr high-perfbrmance liquid chromatography (HPLC) has been estahlished fbr the simultaneous determination of rheinanthrone, sennidin A, scnnidin B and rhein formed by incubation f 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 aqucous 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 ofrheinanthrone fbllowing dehydration treatment with magnesium sulfate. This method is applicable te determine metabolites of sennosides by anaerobic incubation with rat and mouse feces. Key vvords fecal bacterial metaboiism, sennoside A, rheinanthronc, sennidin A, sennidin B, HPLC.