New lathyrane-type diterpenes from Euphorbia boetica
Euphorbia species, commonly named spurge, have been widely used in traditional medicine to treat several diseases, like tumors and warts . From these species, a wide range of structurally unique polyoxygenated macrocyclic diterpenes as jatrophanes, lathyranes and their polycyclic derivatives, have been isolated. These compounds have shown several important biological activities including antiproliferative effects, modulation of multidrug resistance in cancer cells and apoptosis induction [2–4]. Euphorbia boeticaBoiss. is an herb endemic to Europe, commonly found in Southwest of Iberic Peninsula (Algarve and Alentejo). In our continuing investigation for biologically active molecules, the methanol extract of E. boetica aerial parts has been studied. The crude methanolic residue was suspended on a methanol-water mixture and extracted with ethyl acetate. Repeated column chromatographic fractionation and further purification by HPLC of the ethyl acetate soluble part afforded six diterpenes with the lathyrane skeleton that have a new acylation pattern. In addition, a cycloartane triterpene was also isolated and identified. The chemical structures of the isolated compounds, including stereochemical features were deduced from their physical and spectroscopic data, which include: Infrared Spectroscopy, low and high resolution Mass Spectrometry (MS), and extensive one- and two-dimensional Nuclear Magnetic Resonance studies (1D and 2D-NMR).
Acknowledgement: This work was supported by Fundação para a Ciência e Tecnologia (FCT) (Project PTDC/QUI-QUI/099815/2008)
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