title: Synthesis and characterization of synthetic analogs of cinnacidin, a novel phytotoxin from Nectria sp.
abstract: BACKGROUND
  The novel natural product cinnacidin was isolated from a fungal fermentation extract of Nectria sp. DA060097. The compound was found to contain a cyclopentalenone ring system with an isoleucine subunit linked through an amide bond. Initial biological characterization of cinnacidin suggested promising herbicidal activity.
  
  
  RESULTS
  Two synthetic analogs, (2S,3S)-2-[(3RS,3aSR,6aRS)-3-methoxy-4-oxo-3,3a,4,5,6,6a-hexahydropentalen-1-ylcarbamoyl]-3-methylvaleric acid and benzyl (2S,3S)-2-[(3RS,3aSR,6aRS)-3-methoxy-4-oxo-3,3a,4, 5,6,6a-hexahydropentalen-1-ylcarbamoyl]-3-methylvalerate, were prepared for further characterization, and their herbicidal activities were compared with that of cinnacidin.
  
  
  CONCLUSIONS
  The synthetic compounds were highly phytotoxic on a range of weeds. Based on the symptoms in treated plants, the mode of action of these compounds is suggested to be similar to that of coronatine and jasmonic acid. Coronatine was more active against warm-season grasses, while the cinnacidin benzyl ester analog was more effective on cool-season grasses. In a seedling growth bioassay conducted on bentgrass, the cinnacidin analog was equivalent in activity to coronatine.
authors.affiliation: Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268, USA. nmirvine@dow.com
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Irvine
authors.forename: Carla N
authors.initials: CN
authors.lastname: Yerkes
authors.forename: Paul R
authors.initials: PR
authors.lastname: Graupner
authors.forename: Roben E
authors.initials: RE
authors.lastname: Roberts
authors.forename: Don R
authors.initials: DR
authors.lastname: Hahn
authors.forename: Cedric
authors.initials: C
authors.lastname: Pearce
authors.forename: B Clifford
authors.initials: BC
authors.lastname: Gerwick
mesh_terms: D031703:Agrostis / Q000187:drug effects; D000596:Amino Acids / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects; D006540:Herbicides / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006999:Hypocreales / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D007192:Indenes / Q000494:pharmacology; D007532:Isoleucine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D014118:Toxins, Biological / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000596:Amino Acids; D006540:Herbicides; D007192:Indenes; D014118:Toxins, Biological; D007532:Isoleucine; C058487:coronatine