title: Cytotoxic oplopane sesquiterpenoids from Arnoglossum atriplicifolium.
abstract: Pale Indian plantain (Arnoglossum atriplicifolium (L.) H. Rob.) is a plant with traditional medicinal usage among the Cherokee Native American tribe for treating cancer. Two oplopane sesquiterpenoids were isolated from an extract of A. atriplicifolium from Western North Carolina. The compounds were isolated by bioassay-guided fractionation using an MCF-7 breast tumour cell line assay. The known compound (1S,6R,7R,8R)-1-acetoxy-6,7-diangeloxy-8,10-epoxy-2-oxo-oplopa-3,14Z,11,12-dien-13-al (1) had an EC50 value of 9.0 μM against MCF-7 cells, while the new compound (1S,3R,6R,7R,8R,11S)-1-acetoxy-6,7-diangeloxy-8,10,11,13-bisepoxyoplopan-2-one (2) had an EC50 value of 96 μM. The compounds were characterised by 1D and 2D NMR spectroscopy and by comparison with literature values in the case for 1. Based on NOESY analysis, a correction of the relative configuration for 1 is presented. The presence of these compounds may help to explain the folk remedy usage of this plant as an anticancer agent.
authors.affiliation: a Department of Chemistry and Physics , Western Carolina University , Cullowhee , NC , USA.|b Natural Products Discovery Institute , Baruch S. Blumberg Institute , Doylestown , PA , USA.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Clement
authors.affiliation: a Department of Chemistry and Physics , Western Carolina University , Cullowhee , NC , USA.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Bleich
authors.affiliation: a Department of Chemistry and Physics , Western Carolina University , Cullowhee , NC , USA.
authors.forename: Hailey E
authors.initials: HE
authors.lastname: Campbell
authors.affiliation: a Department of Chemistry and Physics , Western Carolina University , Cullowhee , NC , USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Naylor
authors.affiliation: a Department of Chemistry and Physics , Western Carolina University , Cullowhee , NC , USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Flood
authors.affiliation: c Bent Creek Institute , Asheville NC , USA.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Kelly
authors.affiliation: d Department of Biological Sciences, Lehman College , City University of New York , Bronx , NY , USA.
authors.forename: Shi-Biao
authors.initials: SB
authors.lastname: Wu
authors.affiliation: d Department of Biological Sciences, Lehman College , City University of New York , Bronx , NY , USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Kennelly
authors.affiliation: c Bent Creek Institute , Asheville NC , USA.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Schmitt
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007198:Indians, North American; D061986:MCF-7 Cells; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008519:Medicine, Traditional; D010943:Plantago / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: C000618911:(1S,3R,6R,7R,8R,11S)-1-acetoxy-6,7-diangeloxy-8,10,11,13-bisepoxyoplopan-2-one; D000972:Antineoplastic Agents, Phytogenic; D012717:Sesquiterpenes
keywords: Arnoglossum atriplicifolium; Oplopane; sesquiterpenoid