Phytochemical and biological preliminary study of Himatanthus drasticus (Mart.) Plumel (Janaguba)

Himatanthus drasticus (Apocynaceae), popularly known as Janaguba, is a medicinal plant tree, which latex is used by the population of the Cariri region, south of Ceará State, Brazil, as anticancer, among other medicinal uses. The stem bark of H. drasticus was subjected to a phytopharmacological investigation in order to identify its major chemical constituents and to evaluate in preliminary in vitro assays for citotoxic, antimicrobial and antinociceptive activities. One compound was isolated and identified as the triterpene lupeol cinnamate. The ethanolic extract was first evaluated biologically as cytotoxic agent against the brine shrimp lethality test, but showed no antimicrobial effect on the tested pathogens in vitro. The extract had a significant antinociceptive effect on the writhing test while showed no effect on the hot-plate test. This is the first detailed phytochemical investigation of H. drasticus L. growing in Brazil and elsewhere. The isolated compounds are reported from this plant for the first time and their full 1H and 13C-NMR assignments are included.