title: Excisanin H, a novel cytotoxic 14,20-epoxy-ent-kaurene diterpenoid, and three new ent-kaurene diterpenoids from Rabdosia excisa.
abstract: A novel 14,20-epoxy-ent-kaurene diterpenoid, excisanin H (1), and three new ent-kaurene diterpenoids, 2-4, were isolated from aerial parts of Rabdosia excisa along with eight known ent-kaurene diterpenoids, 5-12. The structural elucidations were made using spectral (HREIMS, IR, (1)H, (13)C, and 2D NMR) methods. The absolute configuration of 1 was determined by demonstrating that oxidation of kamebakaurin (8) produced excisanin H (1). These ent-kaurene diterpenoids all showed significant cytotoxic activity against P388 murine leukemia cells.
authors.affiliation: School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Ming-Yu
authors.initials: MY
authors.lastname: Gui
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Aoyagi
authors.forename: Yong-Ri
authors.initials: YR
authors.lastname: Jin
authors.forename: Xu-Wen
authors.initials: XW
authors.lastname: Li
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Hasuda
authors.forename: Koichi
authors.initials: K
authors.lastname: Takeya
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D045786:Diterpenes, Kaurane / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019686:Lamiaceae / Q000737:chemistry*; D007941:Leukemia P388; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D045786:Diterpenes, Kaurane; D004365:Drugs, Chinese Herbal; C484471:excisanin H