Sex pheromone biosynthesis of (E, E)-8,10-dodecadienol in codling moth Cydia pomonella involves E9 desaturation

• Sex pheromone biosynthesis in the codling moth Cydia pomonella (Lepidoptera; Tortricidae) was studied by topical application of deuterated fatty acids in DMSO to pheromone glands. The incorporation of deuterium label into fatty acids and alcohols in the pheromone gland was monitored by gas chromatography with flame ionization detection and mass spectrometry in the selected ion monitoring mode. Dodecanol, (E)-9-dodecenol, (E,E)-8,10-dodecadienol, tetradecanol, and hexadecanol were found in gland extracts. The application of [12,12,12-2H3]dodecanoic acid resulted in labeled dodecanol, (E)-9-dodecenol, and (E,E)-8,10-dodecadienol, as well as the corresponding labeled acids. No label was incorporated into tetradecanol or hexadecanol or any acid with more than 12 carbon atoms. The application of labeled tetradecanoic or hexadecanoic acid introduced label not only into the 12-carbon alcohols, but also into tetradecanol, or tetradecanol and hexadecanol, respectively. The application of (E)-[11, 11,12,12,12,-2H5]9-dodecen-oic acid, whose facile synthesis is described, resulted in labeled (E)-9-do-decenol and (E,E)-8,10-dodecadienol. The (E,E)-8,10-dodecadienol so produced was characterized by an ion at m/z 186, equivalent to [M]+ of a dienol labeled with four deuterons. Thus, one deuterium label is lost when the labeled (E)-9-monoene is converted to the (E,E)-8,10-diene. We conclude that (E,E)-8,10-dodecadienol is synthesized by chain shortening (β-oxidation) of palmitic acid to dodecanoic acid, followed by an unusual E9 desaturation and subsequent conversion of this intermediate into the conjugated precursor, which is finally reduced to the pheromone alcohol. The evolutionary significance of E9 desaturation being responsible for pheromone production in an Olethreutinae species is discussed.

Subject headings

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Keyword

(E)-9-dodecenoic acid

(E,E)-8,10-dodecadienol

biosynthesis

capillary gas chromatography

Cydia pomonella

deuterium

E9 desaturation

labeled precursors

Lepidoptera

palmitic acid

pheromone

Tortricidae

Publication and Content Type

art (subject category)

ref (subject category)