title: (4E)-dehydrocitrals [(2E,4E)- and (2Z,4E )-3,7-dimethyl-2,4,6-octatrienals] from acarid mite Histiogaster sp. A096 (Acari: Acaridae).
abstract: A mixture of two monoterpenes was obtained as the opisthonotal gland secretion from unidentified Histiogaster sp. A096 (Acari: Acaridae), and their structures were elucidated to be (4E)-dehydrocitrals [(2E,4E)- and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienals] by GC/MS, GC/FT-IR, UV and 1H-NMR spectra. Both isomers of (4E)-dehydrocitral prepared by syntheses in 4 steps from 3-methyl-2-butenal with 34.2% yields (based on the ylide) were separated by column chromatography into the (2E,4E)- and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienal. Mass spectra together with GC retention times of the purified natural (4E)-dehydrocitrals were identical with those of synthetic (2E,4E)-3,7-dimethyl-2,4,6-octatrienal and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienal. The geometry at the 2-C position of both synthetic (4E)-dehydrocitrals was confirmed by NOESY analyses. This is the first identification of (4E)-dehydrocitrals from the animal kingdom.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hiraoka
authors.forename: N
authors.initials: N
authors.lastname: Mori
authors.forename: R
authors.initials: R
authors.lastname: Nishida
authors.forename: Y
authors.initials: Y
authors.lastname: Kuwahara
mesh_terms: D000053:Acari / Q000737:chemistry*; D000818:Animals; D002849:Chromatography, Gas; D013057:Spectrum Analysis; D013729:Terpenes / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D013729:Terpenes