Bombykol is a

pheromone A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...

released by the female

silkworm The domestic silk moth (''Bombyx mori''), is an insect from the moth family Bombycidae. It is the closest relative of ''Bombyx mandarina'', the wild silk moth. The silkworm is the larva or caterpillar of a silk moth. It is an economically imp ...

moth to attract mates. It is also the sex pheromone in the wild silk moth (''

Bombyx mandarina ''Bombyx mandarina'', the wild silk moth, is an insect from the moth family Bombycidae. It is the closest relative of '' Bombyx mori'', the domesticated silk moth. The silkworm is the larva or caterpillar of a silk moth. Unlike the domesticated ...

''). Discovered by

Adolf Butenandt Adolf Friedrich Johann Butenandt (; 24 March 1903 – 18 January 1995) was a German biochemist. He was awarded the Nobel Prize in Chemistry in 1939 for his "work on sex hormones." He initially rejected the award in accordance with government po ...

in 1959, it was the first pheromone to be characterized chemically. Minute quantities of this pheromone can be used per acre of land to confuse male insects about the location of their female partners. It can thus serve as a lure in traps to remove insects effectively without spraying crops with large amounts of pesticides. Butenandt named the substance after the moth's Latin name ''Bombyx mori.'' ''In vivo'' it appears that bombykol is the natural ligand for a pheromone binding protein, BmorPBP, which escorts the pheromone to the pheromone receptor.

Biosynthesis

Bombykol is known to be derived from

acetyl-CoA Acetyl-CoA (acetyl coenzyme A) is a molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for ...

via the C-16 fatty acyl palmitoyl-CoA. Palmitoyl-CoA is converted to bombykol in steps that involve desaturation and reductive modification of the carbonyl carbon. Compared to other Type I pheromones, bombykol biosynthesis does not need chain-shortening or any other kind of modification of the terminal hydroxyl group. A desaturase enzyme encoded by the gene Bmpgdesat1 (Desat1), produces the monoene (11''Z'')-hexadecenoyl-CoA as well as the diene (10''E'',12''Z'')-10,12-hexadecadienoyl-CoA. This desaturase is the only enzyme necessary to catalyze these two consecutive desaturation steps. The bombykol acyl precursor (10''E'',12''Z'')-10,12-hexadecadienoate is primarily found as a triacylglycerol ester in the cytoplasmic lipid droplets of pheromone gland cells of the moth. And when the adult females emerge from their pupae, the neurohormone PBAN (pheromone biosynthesis-activating neuropeptide) start signaling events that help control the lipolysis of the stored triacylglycerols, releasing (10''E'',12''Z'')-10,12-hexadecadienoate for its final reductive modification. The mechanism of the lipolytic release of (10''E'',12''Z'')-10,12-hexadecadienoate from triacylglycerols is not completely known but the candidate lipase-encoding genes have been identified.

References

{{reflist Insect pheromones Insect ecology Primary alcohols Conjugated dienes