title: Biosynthesis of tiglic, ethacrylic, and 2-methylbutyric acids in a carabid beetle, Pterostichus (Hypherpes) californicus.
abstract: Tiglic, 2-methylbutyric, and ethacrylic acids are found in the pygidial gland defensive fluid of many carabid beetles. By injecting a deuterium-labeled precursor into the carabid beetle Pterostichus (Hypherpes) californicus, and analyzing the defensive fluid by gas chromatography/mass spectrometry, we were able to demonstrate that tiglic and ethacrylic acids are biosynthesized from isoleucine via 2-methylbutyric acid. Moreover, we observed that the injection of L-isoleucine induces an increased production of tiglic acid in P. californicus. A strong primary kinetic isotope effect was found to operate in the dehydrogenation step of 2-methylbutyric acid to tiglic and ethacrylic acids. Consequently, ethacrylic acid was found to preferentially accumulate the deuterium labeling from [2,3,4,4-(2)H(4)]isoleucine during our biosynthetic experiments.
authors.affiliation: Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA. athula.attygalle@stevens.edu
authors.forename: Athula B
authors.initials: AB
authors.lastname: Attygalle
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Wu
authors.forename: Kipling W
authors.initials: KW
authors.lastname: Will
mesh_terms: D000179:Acrylates / Q000378:metabolism*; D000818:Animals; D002087:Butyrates / Q000378:metabolism*; D001517:Coleoptera / Q000378:metabolism*; D003437:Crotonates / Q000378:metabolism*; D045782:Hemiterpenes; D007532:Isoleucine / Q000494:pharmacology
chemical_list: D000179:Acrylates; D002087:Butyrates; D003437:Crotonates; D045782:Hemiterpenes; D007532:Isoleucine; C009489:tiglic acid; C036658:acrylic acid; C019475:2-methylbutanoic acid