title: 12,17-Cyclojatrophane and Jatrophane Constituents of Euphorbia welwitschii.
abstract: Euphowelwitschines A (1) and B (2), isolated from a methanolic extract of Euphorbia welwitschii, exhibit a rare combination of structural features in having a 5/8/8 fused-ring system and a 12,15-ether bridge. Moreover, the isolation of the additional new compounds welwitschene (3) and epoxywelwitschene (4) has provided insights into the biogenetic pathway of 12,17-cyclojatrophanes. The structures of 1-4 were determined by spectroscopic methods inclusive of 1D and 2D NMR experiments and X-ray crystallography for compounds 1 and 2. Preliminary information on the selective antiproliferative activity of compounds 1-4 is also described.
authors.affiliation: Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa , Avenue Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
authors.forename: Mariana A
authors.initials: MA
authors.lastname: Reis
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa , Avenue Rovisco Pais, 1049-001 Lisbon, Portugal.
authors.forename: Vânia
authors.initials: V
authors.lastname: André
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa , Avenue Rovisco Pais, 1049-001 Lisbon, Portugal.
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Duarte
authors.affiliation: Charité Campus Mitte, Institute of Pathology , D-10117 Berlin, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Lage
authors.affiliation: Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa , Avenue Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
authors.forename: Maria-José U
authors.initials: MJ
authors.lastname: Ferreira
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D028481:Euphorbia / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011174:Portugal
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004224:Diterpenes; C000605745:euphowelwitschine A; C000605746:euphowelwitschine B; C530345:jatrophane