1.How to spoil the taste of insect prey? A novel feeding deterrent against ants released by larvae of the alder leaf beetle, Agelastica alni.
Hilker M1, Häberlein C, Trauer U, Bünnige M, Vicentini MO, Schulz S. Chembiochem. 2010 Aug 16;11(12):1720-6. doi: 10.1002/cbic.201000130.
Chemical defense of leaf beetle larvae (Chrysomelidae) against enemies is provided by secretions containing a wide range of deterrent compounds or by unpalatable hemolymph constituents. Here we report a new, very strong feeding deterrent against ants released by larvae of the alder leaf beetle Agelastica alni when attacked. The larvae release a defensive fluid from openings of pairwise, dorsolaterally located tubercles on the first to the eighth abdominal segments. The fluid, consisting of hemolymph and probably a glandular cell secretion, has previously been shown to contain a very stable, non-volatile feeding deterrent. The major deterrent component was isolated by repeated HPLC separation and analyzed by NMR and MS. The compound proved to be gamma-L-glutamyl-L-2-furylalanine (1), a novel dipeptide containing the unusual amino acid L-2-furylalanine. This amino acid, although synthetically well known, has not previously been reported from natural sources.
