title: Insect antifeedant activity of three new tetranortriterpenoids from Trichilia pallida.
abstract: Three new tetranortriterpenoids, methyl 6-hydroxy-11 beta-acetoxy-12 alpha-(2-methylpropanoyloxy)-3,7-dioxo-14 beta,15 beta-epoxy-1,5-meliacadien-29-oate (3), methyl 6,11 beta-dihydroxy-12 alpha-(2-methylpropanoyloxy)-3,7-dioxo-14 beta,15 beta-epoxy-1,5-meliacadien-29-oate (4), and methyl 6-hydroxy-11 beta-acetoxy-12 alpha-(2-methylbutanoyloxy)-3,7-dioxo-14 beta,15 beta-epoxy-1,5-meliacadien-29-oate (5), have been isolated from the roots of Trichilia pallida. The related compounds hirtin (1) and deacetylhirtin (2) were also obtained. Compound 4 had the greatest antifeedant activity of 1-5 when tested against larvae of four species of Lepidoptera.
authors.affiliation: Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, UK. m.simmonds@rbgkew.org.uk
authors.forename: M S
authors.initials: MS
authors.lastname: Simmonds
authors.forename: P C
authors.initials: PC
authors.lastname: Stevenson
authors.forename: E A
authors.initials: EA
authors.lastname: Porter
authors.forename: N C
authors.initials: NC
authors.lastname: Veitch
mesh_terms: D000818:Animals; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D005247:Feeding Behavior / Q000187:drug effects*; D007814:Larva / Q000187:drug effects; D007915:Lepidoptera / Q000187:drug effects*; D036701:Limonins; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification*; D006113:United Kingdom
chemical_list: D036701:Limonins; D014315:Triterpenes; C437024:deacetylhirtin; C437025:hirtin; C437023:methy-6-hydroxy-11beta-acetoxy-12alpha-(2-methylpropanoyloxy)-3,7-dioxo-14beta,15beta-epoxy-1,5-meliacadien-29-oate; C437027:methyl-6,11beta-dihydroxy-12alpha-(2-methylpropanoyloxy)-3,7-dioxo-14beta,15beta-epoxy-1,5-meliacadien-29-oate; C437026:methyl-6-hydroxy-11beta-acetoxy-12alpha-(2-methylbutanoyloxy)-3,7-dioxo-14beta,15beta-epoxy-1,5-meliacadien-29-oate