Arjunolic acid from the root bark of Terminalia catappa linn

Abstract

Terminalia catappa (Linn.) is used in traditional medicine to treat dysmenorrhea and typhoid fever in the Tiv speaking parts of Benue State, Nigeria. The aim of this study was to investigate the plant for its chemical contents that could be responsible for the reported medicinal activity. Extraction of root bark of the plant was done with n-hexane, ethyl acetate and methanol. The ethyl acetate extract was subjected to column chromatography on silica gel 60H, 200-400 mesh, eluted gradient wise with hexane:ethyl acetate. Fractions (ND95-97) obtained from hexane:ethyl acetate (60:40) were combined based on similar TLC Rf values. On standing, the combined fractions gave a white solid with melting point 230 – 231oC which gave a positive result to the Liebermann-Burchard test for pentacyclic triterpenes. Its mass spectrum showed a molecular ion peak at m/z 506.3879 [M + H2O]+. On the basis of1H,13C, 2D (HMBC, HSQC, COSY) NMR spectral data, mass spectrometry, and by comparison of spectra data with literature, ND95-97 was characterized as Arjunolic acid (2,3,23-trihydroxyolean-12-en-28-oic acid). To the best of our knowledge, this is the first report of the isolation of Arjunolic acid from the root bark of Terminalia catappa.