title: Sesquiterpene lactones as allelochemicals.
abstract: Six new sesquiterpene lactones, annuolide H (3), helivypolides F, H-J (4, 11-13), and helieudesmanolide A (6), together with known compounds, were isolated from polar bioactive fractions of Helianthus annuus cv. SH-222 and Stella fresh leaf water extracts. Spectroscopic analysis of the new data for 1,2-anhydroniveusin A and 1-methoxy-4,5-dihydroniveusin A corrects some previous assignments. The compounds were tested using the etiolated wheat coleoptile bioassay, and the most active compounds were assayed in standard target species (STS) (Lepidium sativum, Allium cepa, Lactucasativa, Lycopersicon esculentum, and Triticum aestivum) from 5 x 10(-4) to 10(-5) M. The most phytotoxic compounds were helivypolide F and 15-hydroxy-3-dehydrodeoxyfruticin, both of which have a carbonyl group at C-3 conjugated with two double bonds.
authors.affiliation: Grupo de Alelopatía, Departamento de Química Organica, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Spain. famacias@uca.es
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Macías
authors.forename: Adriana
authors.initials: A
authors.lastname: Fernández
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Varela
authors.forename: José M G
authors.initials: JM
authors.lastname: Molinillo
authors.forename: Ascensión
authors.initials: A
authors.lastname: Torres
authors.forename: Pedro L C A
authors.initials: PL
authors.lastname: Alves
mesh_terms: D006368:Helianthus / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018545:Lactuca / Q000187:drug effects; D018551:Solanum lycopersicum / Q000187:drug effects; D015394:Molecular Structure; D019697:Onions / Q000187:drug effects; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D013030:Spain; D013329:Structure-Activity Relationship; D014908:Triticum / Q000187:drug effects
chemical_list: D007783:Lactones; D012717:Sesquiterpenes