Insect antifeedants from tropical plants II: structure of zumsin.
A novel A-seco limonoid was isolated from methanolic extract of Croton jatrophoides and designated as zumsin. This compound showed potent antifeedant activity against two lepidopteran larvae, pink bollworm, Pectinophora gossypiella (PC(50) = 1 microg/cm(2), PC(95) = 8 microg/cm(2)), and fall armyworm, Spodoptera frugiperda (PC(50) = 2 microg/cm(2), PC(95) = 16 microg/cm(2)). The structure of zumsin was determined as 1 using a variety of spectroscopic methods including nuclear magnetic resonance, mass spectrometry, and circular dichroism. The structure consists of an A'-B trans-fused ring while dumsin (2), a constituent of the same source, maintains an A'-B cis-fused ring, and suggests two unique biosynthetic processes after A ring oxidative expansion.
Department of Environmental Science, Policy and Management, University of California, Berkeley 94720-3112, USA.
Ken-ichi
K
Nihei
Frederick J
FJ
Hanke
Yukihiro
Y
Asaka
Takeshi
T
Matsumoto
Isao
I
Kubo
D000818:Animals; D002942:Circular Dichroism; D029802:Croton / Q000737:chemistry*; D004435:Eating / Q000187:drug effects; D007306:Insecticides / Q000737:chemistry*; D007814:Larva / Q000502:physiology; D007915:Lepidoptera / Q000254:growth & development / Q000502:physiology; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D000432:Methanol; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry; D018411:Spodoptera / Q000254:growth & development / Q000502:physiology; D014315:Triterpenes / Q000737:chemistry*
D007306:Insecticides; D010936:Plant Extracts; D014315:Triterpenes; C465738:zumsin; D000432:Methanol