title: Limonoids from Nigerian Harrisonia abyssinica and their stimulatory activity against Striga hermonthica seeds.
abstract: Deoxyobacunone (1), a new limonoid with a double bond in ring D, has been isolated from the root bark of Harrisonia abyssinica collected in Nigeria. Also, the known limonoids obacunone (2), harrisonin (3), 12beta-acetoxyharrisonin (4), and pedonin (5) have been isolated. The structure of 1 was assigned unambiguously by spectral data analysis. Under laboratory conditions, 10(-3)-10(-5) M concentrations of compounds 1-5 exhibited significant stimulatory activity (12-98%) against conditioned Striga hermonthica seeds. This study provided useful insight regarding the functionalities required for activity of limonoids against Striga seeds. The variation in activity was rationalized through quantitative structure-activity relationship (QSAR) models based on several molecular descriptors including van der Waals volume (VDW(v)), molecular polarizability (alpha), dipole moment (mu), log P, and the differences between the highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO-LUMO gap).
authors.affiliation: Department of Chemistry, Massachusetts College of Liberal Arts, 375 Church Street, North Adams, Massachusetts 01247, USA. jrugutt@mcla.mass.edu
authors.forename: J K
authors.initials: JK
authors.lastname: Rugutt
authors.forename: K J
authors.initials: KJ
authors.lastname: Rugutt
authors.forename: D K
authors.initials: DK
authors.lastname: Berner
mesh_terms: D001578:Benzopyrans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001584:Benzoxepins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005663:Furans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D036701:Limonins; D008956:Models, Chemical; D008968:Molecular Conformation; D015394:Molecular Structure; D009549:Nigeria; D019906:Nuclear Magnetic Resonance, Biomolecular; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011753:Pyrones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D028083:Scrophulariaceae / Q000737:chemistry* / Q000187:drug effects; D012639:Seeds / Q000737:chemistry / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: C442767:12-acetoxyharrisonin; D001578:Benzopyrans; D001584:Benzoxepins; D005663:Furans; D036701:Limonins; D011753:Pyrones; C442765:deoxyobacunone; C442766:harrisonin; C442768:pedonin; C067207:obacunone