title: Cancer chemopreventive activity of oleanane-type triterpenoids from the stem bark of Betula ermanii.
abstract: In search for cancer chemopreventive agents from natural sources, three oleanane- and four known lupane-type triterpenoids, and sitosterol from the stem bark of Betula ermanii were tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Among them, 3beta-acetoxy-12alpha-hydroxyoleanan-13beta,28-olide (1) and 3beta-acetoxy-11alpha,12alpha-epoxyoleanan-13beta,28-olide (2) were investigated for the inhibitory effect in a two-stage carcinogenesis test on mouse skin using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter. 3beta-Acetoxy-11alpha,12alpha-epoxyoleanan-13beta,28-olide (2) was found to exhibit the potent antitumor promoting activity in the in vivo carcinogenesis test.
authors.affiliation: Department of Medicinal Chemistry, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan.
authors.forename: Chiharu
authors.initials: C
authors.lastname: Yamaguchi
authors.forename: Yasuko
authors.initials: Y
authors.lastname: In
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Wada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamada
authors.forename: Harukuni
authors.initials: H
authors.lastname: Tokuda
authors.forename: Reiko
authors.initials: R
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D000956:Antigens, Viral / Q000187:drug effects / Q000378:metabolism; D029662:Betula / Q000737:chemistry*; D015197:Carcinogenicity Tests; D005260:Female; D051379:Mice; D008813:Mice, Inbred ICR; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D010212:Papilloma / Q000139:chemically induced / Q000517:prevention & control; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D012878:Skin Neoplasms / Q000139:chemically induced / Q000517:prevention & control; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D016588:Anticarcinogenic Agents; D000956:Antigens, Viral; C033305:Epstein-Barr virus early antigen; D014315:Triterpenes; C413246:oleanane; D009828:Oleanolic Acid; D013755:Tetradecanoylphorbol Acetate