Limonoids from Nigerian Harrisonia abyssinica and Their Stimulatory Activity against Striga hermonthica Seeds

• Published in: Journal of natural products (Washington, D.C.) Vol. 64; no. 11; pp. 1434 - 1438
• Main Authors: RUGUTT, Joseph K., RUGUTT, Kipngeno J., BERNER, Dana K.
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 01.11.2001; Amer Chemical Soc; American Society of Pharmacognosy
• Subjects: Benzopyrans - chemistry; Benzopyrans - isolation & purification; Benzopyrans - pharmacology; Benzoxepins - chemistry; Benzoxepins - isolation & purification; Benzoxepins - pharmacology; Biological and medical sciences; Chemical Phenomena; Chemistry, Medicinal; Chemistry, Physical; Fundamental and applied biological sciences. Psychology; Furans - chemistry; Furans - isolation & purification; Furans - pharmacology; Life Sciences & Biomedicine; Limonins; Models, Chemical; Molecular Conformation; Molecular Structure; Nigeria; Nuclear Magnetic Resonance, Biomolecular; Parasitic plants; Parasitic plants. Weeds; Pharmacology & Pharmacy; Phytopathology. Animal pests. Plant and forest protection; Plant Roots - chemistry; Plant Sciences; Plants, Medicinal - chemistry; Pyrones - chemistry; Pyrones - isolation & purification; Pyrones - pharmacology; Science & Technology; Scrophulariaceae - chemistry; Scrophulariaceae - drug effects; Seeds - chemistry; Seeds - drug effects; Structure-Activity Relationship; Niger; Africa; ETHYLENE; RUTALES; CITRUS BITTER PRINCIPLES; NMR-SPECTROSCOPY; BIOSYNTHESIS; GERMINATION; SPECTRA; ASSIGNMENTS; Terpenoid; Seeds; Root; Germination; Bark; Furan derivatives; Lactone; Tetracyclic compound; Oxygen heterocycle; Modeling; Medicinal plant; Simaroubaceae; Structure activity relation; Dicotyledones; Angiospermae; Molecular model; Plant origin; Triterpene; Scrophulariaceae; Isolation; Plant growth substance; Spermatophyta; Parasitic plant; Structural analysis
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/np0100183

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), 12 beta -acetoxyharrisonin (4), and pedonin (5) have been isolated. The structure of 1 was assigned unambiguously by spectral data analysis. Under laboratory conditions, 10(-8)-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 (VDWv), 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).