HPLC method to assay total saponins in Ilex paraguariensis aqueous extract

Abstract

Ilex paraguariensis St. Hilaire is a South American tree from which leaves and twigs are used to prepare a commonly consumed tea in several South American countries. The plant is known as "erva-mate" in Portuguese or "yerba mate" in Spanish. Considering the potential use of the saponins as surfactant as well as its therapeutic potential, the present work was designed to propose extraction and quantitation methods for the saponins present in Ilex paraguariensis. The saponins were extracted by decoction, hydrolyzed and quantified by a HPLC method with UV detection. The saponins concentration was expressed in ursolic acid (total saponins). The method showed linearity for ursolic acid in the range of 13.5 to 135 μg mL-1. The aqueous extract presented total saponins concentration of 352 μg mL-1. The results also suggest the possibility of use of similar method for assaying triterpenoid saponins in other plants. ©2005 Sociedade Brasileira de Química.