title: Labdane and kaurane diterpenoids from Plectranthus fruticosus.
abstract: Six new diterpenoids, three labdane and three kaurane derivatives, have been isolated from an acetone extract of Plectranthus fruticosus together with other already known substances. The structures of these compounds (1-5 and 7) were established mainly by spectroscopic means, particularly by 1D and 2D NMR studies, as well as by some chemical correlations with known diterpenoids. The physical and spectroscopic data of the derivative 11, obtained by hydrolysis of the labdane 2, were identical to those reported for a compound previously isolated from Croton joufra, to which structure 12 had been established erroneously by other authors. Several of the isolated compounds were tested as antimicrobial agents against three bacteria strains and one yeast strain, but only 4 showed a moderate inhibitory activity against Staphylococcus aureus.
authors.affiliation: Faculdade de Farmácia da Universidade de Lisboa, Centro de Estudos de Ciências Farmacêuticas (CECF), Avenida das Forças Armadas, P-1649-019 Lisboa, Portugal.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gaspar-Marques
authors.forename: M Fátima
authors.initials: MF
authors.lastname: Simões
authors.forename: Aida
authors.initials: A
authors.lastname: Duarte
authors.forename: Benjamín
authors.initials: B
authors.lastname: Rodríguez
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D029802:Croton / Q000737:chemistry; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010946:Plants, Medicinal / Q000737:chemistry*; D031346:Plectranthus / Q000737:chemistry*; D011174:Portugal; D013211:Staphylococcus aureus / Q000187:drug effects*; D013237:Stereoisomerism
chemical_list: D000900:Anti-Bacterial Agents; D004224:Diterpenes; C433017:labdane