Isolation, characterization, and anthelminthic activities of a novel dichapetalin and other constituents of Dichapetalum filicaule

Context: Dichapetalum filicaule Breteler (Dichapetalaceae) is a rare species occurring only in Côte d’Ivoire and Ghana. Although research on several species of the genus has produced interesting bioactive compounds, particularly the Dichapetalins, a novel class of triterpenoids with antineoplastic properties, there is virtually no information on the ethnobotanical uses and chemical constituents of D. filicaule. Objective: The phytochemical and anthelminthic activities of the constituents of D. filicaule were investigated. Materials and methods: Chemical constituents of the petroleum ether, chloroform–acetone, and methanol root extracts of D. filicaule were isolated by column chromatography and characterized by their physico-chemical properties, 1-D and 2-D NMR spectroscopy and mass spectrometry. In vitro anthelminthic activity of the extracts and compounds against the human hookworm, Necator americanus, Stiles 1902 (Nematoda: Ancylostomatidae) was determined within a concentration range of 2500–250 μg/ml using the Egg Hatch Inhibition (EHI) Assay. The hookworm species were identified using a published polymerase chain reaction (PCR) method. Results: A new dichapetalin, dichapetalin X (1), together with the known dichapetalin A (2), pomolic acid (3), glycerol monostearate (4), D:A-friedooleanan-3β-ol (5), and D:A-friedooleanan-3-one (6) were isolated. Compounds 1, 2, and 4 exhibited EHI with IC₅₀ values of 523.2, 162.4, and 306.0 μg/ml, respectively, against the hookworm. The positive control albendazole gave an IC₅₀ value of 93.27 μg/ml. Discussion and conclusion: This is the first report of the phytochemical investigation of D. filicaule. The study has yielded a new dichapetalin and also demonstrated the potential anthelminthic properties of the constituents.