title: Synthesis and insect antifeedant activity of aurones against Spodoptera litura larvae.
abstract: A series of aurones were prepared from various phenols via phenoxy acetic acids and coumaranones and evaluated for insect antifeedant activity against the common cutworm (Spodoptera litura). The naturally occurring aurone was most active at an ED50 of 0.12 micromol/cm2. The synthetic precursor, coumaranones, showed that the introduction of methoxyl and methyl groups to the benzene ring increased insect antifeedant activity. Similarly, the tested aurones showed that the introduction of methoxyl group to the A and/or B rings increased the insect antifeedant activity, but 4,5,6- and 3',4',5'-trisubstituted compounds did not show this activity in this test. The hydroxylation of aurones in the B ring should be disadvantageous for insect antifeedant activity against S. litura. Although the melting points did not correlate well with the insect antifeedant activity, compounds that were nearly inactive had high melting points. A significant correlation was noted between biological activity (pED50) and a hydrogen-bonding parameter calculated from the Rf value obtained from SiOH thin-layer chromatography and a lipophilicity parameter (log k) calculated from the retention time in ODS high-performance liquid chromatography. The respective correlation coefficients (r) were -0.83 and -0.70. The introduction of alkoxy and alkyl groups along with adequate hydrogen bonding seems to contribute to the antifeedant activity of the compounds tested.
authors.affiliation: Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara, Japan. masanori@nara.kindai.ac.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Morimoto
authors.forename: Hiromi
authors.initials: H
authors.lastname: Fukumoto
authors.forename: Toki
authors.initials: T
authors.lastname: Nozoe
authors.forename: Ai
authors.initials: A
authors.lastname: Hagiwara
authors.forename: Koichiro
authors.initials: K
authors.lastname: Komai
mesh_terms: D000085:Acetates / Q000737:chemistry; D000818:Animals; D001572:Benzofurans / Q000138:chemical synthesis* / Q000494:pharmacology; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004435:Eating / Q000187:drug effects; D007306:Insecticides / Q000138:chemical synthesis*; D007814:Larva / Q000502:physiology*; D010756:Phosphoric Acids / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D018411:Spodoptera / Q000502:physiology*; D013329:Structure-Activity Relationship
chemical_list: D000085:Acetates; D001572:Benzofurans; D007306:Insecticides; D010756:Phosphoric Acids; D011108:Polymers; C486837:aurone; C047269:polyphosphoric acid; C415326:phenoxyacetic acid