CHEMICAL AND PHARMACOLOGICAL EVALUATION OF<i>DESMODIUM PULCHELLUM</i>

Abstract

Fifteen simple indolic bases (I–XV) representing three broad structural types, viz., indole–3–alkylamine, β–carboline, and tetrahydro–β–carboline, have been isolated from the various individual parts of Desmodium pulchellum collected during different periods of its growth. Seven of these compounds, (IV, VIII, X–XIII, XV), have been found to occur naturally for the first time. In addition, several unidentified quaternary β–carbolines and non–basic 3–alkylindoles have been isolated and their skeletal pattern determined through spot reactions and spectroscopic methods. The content of N,N–dimethyltryptamine, which is a key intermediate in the metabolism of tryptophan in plants, gradually depleted as the congener bases appeared and accumulated in the different parts of the plant. The major accumulation of the Nb–oxides has been observed in the fruits, while the quaternary bases have been localized in the roots. The results of pharmacological studies indicate that the medicinal properties of the plant extracts are due to their contained alkaloids.