title: Diterpenoids from Neoboutonia glabrescens (Euphorbiaceae).
abstract: Glabrescin, a daphnane diterpenoid, neoboutonin, a degraded diterpenoid with a novel skeleton, and neoglabrescins A and B, two rhamnofolane derivatives, have been isolated from the stem bark of Neoboutonia glabrescens Prain (Euphorbiaceae), together with the known tigliane derivative, baliospermin, and the known daphnane, montanin. Other constituents include squalene, 3-acetylaleuritolic acid, oleanolic acid and sitosterol, and the phenolic compounds 9-methoxy-1,7-dimethylphenanthrene and 2,3,8-tri-O-methylellagic acid. The structures were assigned on the basis of spectral studies and comparison with published literature data. The structures of neoglabrescins A and B were derived for their acetylated derivatives and, in the case of neoglabrescin A, confirmed by X-ray crystallographic analysis.
authors.affiliation: Department of Chemistry, University of Dschang, Box 67, Dschang, Cameroon.
authors.forename: Alembert T
authors.initials: AT
authors.lastname: Tchinda
authors.forename: Apollinaire
authors.initials: A
authors.lastname: Tsopmo
authors.forename: Mathieu
authors.initials: M
authors.lastname: Tene
authors.forename: Pierre
authors.initials: P
authors.lastname: Kamnaing
authors.forename: David
authors.initials: D
authors.lastname: Ngnokam
authors.forename: Pierre
authors.initials: P
authors.lastname: Tane
authors.forename: Johnson F
authors.initials: JF
authors.lastname: Ayafor
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Connolly
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Farrugia
mesh_terms: D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification*; D019665:Euphorbiaceae / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry
chemical_list: D004224:Diterpenes