title: 8,15-epoxylabdane and norlabdane diterpenoids from Eragrostis viscosa.
abstract: Four labdanes with a 8alpha,15-epoxy ring (8alpha,15-epoxylabdan-16beta-oic acid; 8alpha,15-epoxy-16-norlabdan-13-one; 8alpha,15-epoxy-16-norlabdane; and 16-acetoxy-8alpha,15-epoxylabdane) and the known compound ambreinolide were isolated from the hexane extract of the aerial parts of the grass Eragrostis viscosa. The structures of all compounds were established based on spectroscopic data and the X-ray analysis of 8alpha,15-epoxy-16-norlabdan-13-one. The hexane extract presented moderate activity against the snail Biomphalaria glabrata. 8alpha,15-Epoxylabdan-16beta-oic acid showed no mutagenic activity for doses up to 1000 microg/plate and no significant clastogenic activity for doses up to 100 microg/ml.
authors.affiliation: Chemistry Department, Agostinho Neto University, Luanda, Angola.
authors.forename: N'Soki N
authors.initials: NN
authors.lastname: Sebastião
authors.forename: Inês J S
authors.initials: IJ
authors.lastname: Cordeiro
authors.forename: Aldenir F
authors.initials: AF
authors.lastname: dos Santos
authors.forename: Jorge F
authors.initials: JF
authors.lastname: Gaspar
authors.forename: Célia
authors.initials: C
authors.lastname: Martins
authors.forename: José
authors.initials: J
authors.lastname: Rueff
authors.forename: Carlos
authors.initials: C
authors.lastname: Diakanamwa
authors.forename: Antônio E G
authors.initials: AE
authors.lastname: Sant'Ana
authors.forename: Dina I M D
authors.initials: DI
authors.lastname: de Mendonça
mesh_terms: D000818:Animals; D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000032:analysis*; D031750:Eragrostis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D012908:Snails
chemical_list: D004224:Diterpenes