Characterization and Identification of Novel Steroids from Nauclea pobeguinii Leaves

Nauclea pobeguinii is a plant in the Rubiaceae family endemic to the swamp forest region of the world. Its extract is widely used in traditional medicine for the treatment of a wide variety of ailments such as malarial, Jaundice, gonorrhea, fever, and stomach discomfort. While other parts of the plant have been examined for the bioactive principles responsible for the medicinal properties, limited information is available in the literature as regards the leaves, hence this study. N. pobeguinii leaves were collected, air-dried, and pulverized. The pulverized sample was extracted with solvents (n-hexane, ethyl acetate, and ethanol) of varying polarity to obtain the crude extracts. Repeated column and thin layer chromatographic separation of the crude extracts afforded three compounds, which were characterized by their IR, 1H, 13C-NMR, and 2D-NMR spectral data. A comparison of the data with literature confirmed the compounds to be 2-hydroxylstigmastane acetate (1), Ergosta-5,6-epoxy-22-en-3-yl-acetate (2), and β-sitosterol (3). Compounds 1 and 2 are novel to N. pobeguinii.