High performance liquid chromatography of zanhic acid glycoside in alfalfa (Medicago sativa)

The aerial parts of alfalfa (Medicago sativa L.) contain a considerable amount of zanhic acid tridesmoside which, due to its low activity, cannot be determined using standard biological procedures. A high performance liquid chromatographic method has been developed for its determination. The procedure employs the alkaline hydrolysis of the tridesmoside followed by the derivatization of released prosapogenins with 4-bromophenacyl bromide. It is demonstrated that alkaline hydrolysis of tridesmoside generates different prosapogenins depending on the solvent used. The conditions for alkaline hydrolysis has been optimised.