(R)-(+)-palasonin, a cantharidin-related plant toxin, also occurs in insect hemolymph and tissues.
Gas chromatographic and mass spectroscopic analyses of extracts of cantharidin-containing meloid, clerid, and staphylinid beetles revealed the presence of minor to significant amounts of palasonin, previously only known from seeds and fruits of the Indian shrub Buteafrondosa (Leguminaceae). Unlike (S)-(-)-palasonin (> 99% ee) from B. frondosa, the insects produce palasonin of low ee with the (R)-(+)-enantiomer (0-50% ee) prevailing. The ee of palasonin from individual specimens of predatory insects (Trichodes apiarius), which acquire their chemical protection from cantharidin-producing insects, may vary considerably. The absolute configuration of (S)-(-)-palasonin, previously deduced from indirect chemical and spectroscopic methods, was confirmed by X-ray crystal structure analysis of a cyclic imide derived from (S)-(-)-palasonin and (S)-(-)- 1 -(4-nitrophenyl)-ethylamine.
Max Planck Institute for Chemical Ecology, Jena, Germany.
Oliver
O
Fietz
Konrad
K
Dettner
Helmar
H
Görls
Kerstin
K
Klemm
Wilhelm
W
Boland
D000818:Animals; D001952:Bridged-Ring Compounds / Q000737:chemistry* / Q000302:isolation & purification; D002193:Cantharidin / Q000737:chemistry* / Q000302:isolation & purification; D001517:Coleoptera / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry* / Q000302:isolation & purification; D007887:Fabaceae / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006458:Hemolymph / Q000737:chemistry; D007509:Irritants / Q000737:chemistry* / Q000302:isolation & purification; D010945:Plants, Edible / Q000737:chemistry; D012639:Seeds / Q000737:chemistry
D001952:Bridged-Ring Compounds; D004852:Epoxy Compounds; D007509:Irritants; C470227:palasonin; D002193:Cantharidin