Title: 1,10-Epoxyhypocretenolides from the Azorean Endemic Leontodon rigens (Asteraceae)
Volume: 2
Issue: 5
Author(s): C. Zidorn, E.- P. Ellmerer, G. Konwalinka, K.- H. Ongania, R. Schwaha, R. Greil, K. Joehrer, N. B. Perry and H. Stuppner
Affiliation:
Keywords:
asteraceae, leontodon rigens, natural products, sesquiterpene lactone epoxides, cytotoxicity
Abstract: A methanolic extract of Leontodon rigens (Dryander in Aiton) Paiva & Ormonde yielded 1,10- epoxy-14-hydroxyhypocretenolide-β-D-glucopyranoside and its 6-O-p-hydroxyphenylacetyl derivative. These compounds represent the first epoxyguaian-12,5-olide derivatives. The structures were established by means of high resolution mass spectrometry and 1-D and 2-D NMR spectroscopy. The cytotoxicity of the isolated compounds was assessed using the MTT assay and their potential to induce apoptosis by employing the annexin V-PI assay.