Open AccessBiosynthesis of scarab beetle pheromones
Author(s) -
Leal Walter Soares,
Zarbin Paulo H. G.,
Wojtasek Hubert,
Ferreira José Tércio
Publication year - 1999
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1999.00018.x
Subject(s) - palmitoleic acid , stereochemistry , stereospecificity , chemistry , hydroxylation , fatty acid , oleic acid , carboxylic acid , sex pheromone , stearic acid , palmitic acid , organic chemistry , biology , biochemistry , botany , enzyme , catalysis
Chemical communication in scarab beetles (Coleoptera: Scarabaeidae) is achieved with a wide variety of pheromones, but one typical structure is the γ‐lactone having a long unsaturated hydrocarbon chain. Several species utilize ( R,Z )‐5‐(–)‐(oct‐1‐enyl)‐oxacyclopentan‐2‐one (buibuilactone), ( R,Z )‐5‐(–)‐(dec‐1‐enyl)‐oxacyclopentan‐2‐one and ( S,Z )‐5‐(+)‐(dec‐1‐enyl)‐oxacyclopentan‐2‐one [( R )‐japonilure and ( S )‐japonilure]. Using deuterated precursors, we have demonstrated that these compounds are biosynthesized from fatty acids. (9,10‐d 4 )‐Palmitic acid, (9,10‐d 4 )‐stearic acid, (9,10‐d 2 )‐palmitoleic acid, (9,10‐d 2 )‐oleic acid, (9,10‐d 2 )‐8‐hydroxypalmitoleic acid and (9,10‐d 2 )‐8‐hydroxyoleic acid were readily incorporated by female Anomala cuprea into the pheromone molecules, while ( Z )‐(5,6‐d 2 )‐5‐dodecenoic acid and ( Z )‐(5,6‐d 2 )‐5‐tetradecenoic acid were not. Therefore, the reaction pathway starts from saturated fatty acids, involves their desaturation, followed by 8‐hydroxylation, chain shortening and cyclization. The products obtained from racemic (9,10‐d 2 )‐8‐hydroxypalmitoleic acid and (9,10‐d 2 )‐8‐hydroxyoleic acid were also racemic, implying that the steps following hydroxylation were not stereospecific. Perdeuterated palmitic acid was applied to disclose the mechanism of the unique hydroxylation reaction. Retention of all deuterium atoms implied that this reaction was a direct process mediated by a specific fatty acid hydroxylase, and preceding desaturation or epoxidation was not involved.