title: First seco-C oleananes from nature.
abstract: [structure: see text] The triterpenes 8,14-seco-oleana-8(26),13-dien-3beta-ol (1) and its acetyl derivative 2 were isolated from Stevia viscida and Stevia eupatoria, respectively. Their structures were elucidated by 2D NMR, including carbon-carbon connectivity experiments, and confirmed by X-ray diffraction analysis of ketone 3. The absolute configuration was determined by NMR analysis of the Mosher esters of 1. The biogenetic implications of the new substances are discussed.
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Apartado 137, Morelia, Michoacán, 58000 Mexico. lroman@zeus.umich.mx
authors.forename: Luisa U
authors.initials: LU
authors.lastname: Román
authors.forename: Diana
authors.initials: D
authors.lastname: Guerra-Ramírez
authors.forename: Gerardo
authors.initials: G
authors.lastname: Morán
authors.forename: Iván
authors.initials: I
authors.lastname: Martínez
authors.forename: Juan D
authors.initials: JD
authors.lastname: Hernández
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Cerda-García-Rojas
authors.forename: J Martín
authors.initials: JM
authors.lastname: Torres-Valencia
authors.forename: Pedro
authors.initials: P
authors.lastname: Joseph-Nathan
mesh_terms: D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D009828:Oleanolic Acid / Q000031:analogs & derivatives*; D036625:Stevia / Q000737:chemistry*; D014315:Triterpenes
chemical_list: C496878:8,14-seco-oleana-8(26),13-dien-3-one; C496876:8,14-seco-oleana-8(26),13-dien-3beta-ol; D014315:Triterpenes; D009828:Oleanolic Acid