title: ent-Rosane and abietane diterpenoids as cancer chemopreventive agents.
abstract: Two ent-rosane- (cuzcol, 1 and 6-dehydroxycuzcol, 2) and a abietatriene- (salvadoriol, 3) type diterpenoids have been isolated from Maytenus cuzcoina and Crossopetalum uragoga, respectively, along with five known diterpene compounds (4-8). Their stereostructures have been elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques, and computational data. The absolute configuration of cuzcol was determined by application of Riguera ester procedure. This is the first instance of isolation of ent-rosane diterpenoids from species of the Celastraceae. The isolated diterpenes were found to be potent anti-tumour-promoter agents, and carnosol (7) also showed a remarkable chemopreventive effect in an in vivo two-stage carcinogenesis model.
authors.affiliation: Instituto Universitario de Bio-Orgánica Antonio González, Departamento de Química Orgánica, Universidad de La Laguna, Avda. Astrofísico Francisco, Sánchez 2, La Laguna, 38206 Tenerife, Canary Islands, Spain.
authors.forename: Marvin J
authors.initials: MJ
authors.lastname: Núñez
authors.forename: Carolina P
authors.initials: CP
authors.lastname: Reyes
authors.forename: Ignacio A
authors.initials: IA
authors.lastname: Jiménez
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Hayashi
authors.forename: Harukuni
authors.initials: H
authors.lastname: Tokuda
authors.forename: Isabel L
authors.initials: IL
authors.lastname: Bazzocchi
mesh_terms: D045784:Abietanes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D029753:Celastraceae / Q000737:chemistry*; D018592:Cross-Over Studies; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D019309:Epstein-Barr Virus Nuclear Antigens / Q000187:drug effects; D005260:Female; D029755:Maytenus / Q000737:chemistry*; D051379:Mice; D008813:Mice, Inbred ICR; D008954:Models, Biological; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010212:Papilloma / Q000188:drug therapy; D010568:Peru; D024301:Plant Bark / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D012867:Skin / Q000187:drug effects
chemical_list: C558136:6-dehydroxycuzcol; D045784:Abietanes; D016588:Anticarcinogenic Agents; D004224:Diterpenes; D019309:Epstein-Barr Virus Nuclear Antigens; C558135:salvadoriol; C068623:carnosol