title: 3-Oxo-12alpha-hydroxyfriedelane from Maytenus gonoclada: structure elucidation by (1)H and (13)C chemical shift assignments and 2D-NMR spectroscopy.
abstract: The compounds 3-oxofriedelane (1), 3beta-hydroxyfriedelane (2), 3,11-dioxofriedelane (3), 3,16-dioxofrie delane (4) and 3-oxo-12alpha-hydroxyfriedelane (5) were isolated from the hexane extract of Maytenus gonoclada Mart. (Celastraceae) leaves. Structural formula and the stereochemistry of the new pentacyclic triterpene 3-oxo-12alpha-hydroxyfriedelane (5) were established through (1)H and (13)C NMR and DEPT 135 spectral data including 2D experiments (HMBC, HMQC, COSY, and NOESY) and mass spectrometry (GC-MS).
authors.affiliation: NEPLAM - Departamento de Química, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Mauro Lúcio G
authors.initials: ML
authors.lastname: Oliveira
authors.forename: Lucienir Pains
authors.initials: LP
authors.lastname: Duarte
authors.forename: Grácia Divina F
authors.initials: GD
authors.lastname: Silva
authors.forename: Sidney Augusto Vieira
authors.initials: SA
authors.lastname: Filho
authors.forename: Vagner Fernandes
authors.initials: VF
authors.lastname: Knupp
authors.forename: Fernando Gomes P
authors.initials: FG
authors.lastname: Alves
mesh_terms: D002240:Carbohydrate Sequence; D002247:Carbon Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D029755:Maytenus / Q000737:chemistry*; D009587:Nitrogen Isotopes; D014315:Triterpenes / Q000737:chemistry*
chemical_list: C525101:3-oxo-12alpha-hydroxyfriedelane; D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D014315:Triterpenes