title: New cytotoxic lupane lactones from Kokoona ochracea.
abstract: Three new compounds, ochraceolides A, B, and C, were isolated from nonpolar extracts derived from Kokoona ochracea stem bark. Based on spectroscopic data, their structures were determined to be the closely related lupane lactones: 3-oxolup-20(29)-en-30,21 alpha-olide, 20,29-epoxy-3-oxolupan-30,21 alpha-olide, and 3,6-dioxolup-20(29)-en-30,21 alpha-olide. Compounds 1 and 3 exhibited significant cytotoxic activity with cultured P-388 cells (ED50 values of 0.26 and 0.53 microgram/ml, respectively) but were at least tenfold less active with a variety of human tumor cell lines. Compound 2 was weakly active with cultured P-388 and KB-3 cells (ED50 values of 7.8 and 5.2 micrograms/ml, respectively), but no significant activity was observed with other human cancer cell types (ED50 values of more than 20 micrograms/ml).
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois, Chicago 60612.
authors.forename: O D
authors.initials: OD
authors.lastname: Ngassapa
authors.forename: D D
authors.initials: DD
authors.lastname: Soejarto
authors.forename: C T
authors.initials: CT
authors.lastname: Che
authors.forename: J M
authors.initials: JM
authors.lastname: Pezzuto
authors.forename: N R
authors.initials: NR
authors.lastname: Farnsworth
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007941:Leukemia P388 / Q000188:drug therapy; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D000094042:Lupanes
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D014315:Triterpenes; C073634:ochraceolide A; D000094042:Lupanes; C073635:ochraceolide B; C073637:ochraceolide C