Alkaloids from the Stems of Enicosanthellum Pulchrum (King) Heusden

Enicosanthellum pulchrum (King) Heusden belongs to the plant family Annonaceae, is a coniferous tree with green flowers. This study was carried out to isolate and identify the chemical constituents present in the methanol extract of E. pulchrum stems. The plant sample was extracted with hexane, ethyl acetate and methanol successively using Soxhlet apparatus. The methanol extract was then subjected to vacuum liquid chromatography eluted with gradient solvent systems of hexane-ethyl acetate (100:0-0:100) and ethyl acetate-methanol (100:0-0:100) to give eight fractions (I-VIII). Repeated column chromatography of fraction II has led to the isolation of three alkaloids, namely, liriodenine, lysicamine and liridine. Structure elucidation of the isolated compounds was accomplished by means of spectroscopic techniques, as well as by comparison of their spectral data with those reported in the literature.