title: Structural determination of 3beta-stearyloxy-urs-12-ene from Maytenus salicifolia by 1D and 2D NMR and quantitative 13C NMR spectroscopy.
abstract: Six pentacyclic triterpenoids, 3beta-stearyloxy-urs-12-ene (1), friedelin (2), 3beta-friedelinol (3), alpha-amyrin (4), beta-amyrin (5), and lupeol (6), have been isolated from the hexane extract of Maytenus salicifolia Reissek (Celastraceae) leaves. The molecular and structural formula as well as the stereochemistry of a new pentacyclic triterpene (1) were determined using data obtained from 1H and 13C NMR spectra, DEPT135 and by 2D HSQC, HMBC, COSY and NOESY experiments. The molecular formula C48H84O2 was established using quantitative 13C NMR, and the molecular weight (692 Da) was confirmed by elemental analysis 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: R R S
authors.initials: RR
authors.lastname: Miranda
authors.forename: G D F
authors.initials: GD
authors.lastname: Silva
authors.forename: L P
authors.initials: LP
authors.lastname: Duarte
authors.forename: I C P
authors.initials: IC
authors.lastname: Fortes
authors.forename: S A Vieira
authors.initials: SA
authors.lastname: Filho
mesh_terms: D002247:Carbon Isotopes; D009682:Magnetic Resonance Spectroscopy; D029755:Maytenus / Q000737:chemistry*; D015394:Molecular Structure; D011083:Polycyclic Compounds / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry*
chemical_list: C511577:3beta-stearyloxy-urs-12-ene; D002247:Carbon Isotopes; D011083:Polycyclic Compounds; D014315:Triterpenes