title: Helikauranoside a, a new bioactive diterpene.
abstract: A new ent-kaurane glucoside, named helikauranoside A (4), was isolated from the aerial parts of Helianthus annuus L. together with three known ent-kaurane-type diterpenoids: (-)-kaur-16-en-19-oic acid (1), grandifloric acid (2), and paniculoside IV (3). The structure of 4 was determined by using a combination of 1D (1H-NMR and 13C-NMR) and 2D (COSY, HSQC, and HMBC) NMR techniques. Bioactivity spectra of isolated compounds were tested by using the etiolated wheat coleoptile bioassay in aqueous solutions at concentrations ranging from 10(-3) to 10(-6)M. Helikauranoside A (4) was the most active (-84%, 10(-3)M; -56%, 10(-4)M). These results suggest that this new compound may be involved in defense mechanisms of H. annuus.
authors: Grupo de Alelopatía, Departamento de Química Organica, Facultad de Ciencias, Universidad de Cádiz, C/ República Saharaui s/n, Apdo. 40, 11510, Puerto Real, Cádiz, Spain. famacias@uca.es
authors: Francisco A
authors: FA
authors: Macías
authors: Adriana
authors: A
authors: López
authors: Rosa M
authors: RM
authors: Varela
authors: Ascensión
authors: A
authors: Torres
authors: José M G
authors: JM
authors: Molinillo
mesh_terms: D004224:Diterpenes / Q000032:analysis* / Q000494:pharmacology*; D006368:Helianthus / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010675:Pheromones / Q000032:analysis / Q000494:pharmacology; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D014908:Triticum / Q000187:drug effects* / Q000254:growth & development
chemical_list: D004224:Diterpenes; D010675:Pheromones; D010936:Plant Extracts