Herbal medicines and infectious diseases: Characterization by LC-SPE-NMR of some medicinal plant extracts used against malaria

Abstract

The extracts of two medicinal plants used in traditional medicine against malaria were characterized by means of an LC-SPE-NMR and LC-MS platform. The structure of a series of major constituents from Bafodeya benna, as well as minor constituents from Ormocarpum kirkii, was determined. Bafodeya benna was found to contain (2R,3R)-taxifolin-3-O-α-L-rhamnoside or astilbin, and its isomers neoastilbin, neoisoastilbin, and isoastilbin, as well as quercetin-3-O-α-L-rhamnoside. From Ormocarpum kirkii, a series of known flavonoids and biflavonoids was obtained, as well as three new compounds, i.e., 7,7-di-O-β-D-glucosyl-()-chamaejasmin, 7-O-β-D-glucosyl-(I-3,II-3)- biliquiritigenin, and isovitexin-(I-3,II-3)-naringenin. The isolated constituents may explain, at least in part, the traditional use against malaria. LC-SPE-NMR, in combination with LC-MS, is a powerful tool for the fast characterization of plant extracts, in order to define priorities at an early stage of a fractionation procedure. In addition, herbal medicinal products can completely be characterized, both with regard to their major as well as their minor constituents. © Georg Thieme Verlag KG Stuttgart - New York.