Figure 1. Simplified biosynthetic
pathway of the Heliothis subflexa sex pheromone, modified from
(Groot et al., 2009b) with permission. Desaturation and β-oxidation
produce mono-unsaturated acyl-CoA precursors from 18 or 16 carbon acyl
CoA derivatives, which are then modified to form acetate esters,
alcohols, and aldehydes through specific enzymatic conversions. The ∆9
and ∆11 desaturases create a double bond between the
9th and 10th or
11th and 12th carbon of the 18- or
16-carbon acyl-CoA derivatives, respectively. β-oxidation shortens the
chain length from 18 to 16 carbons. Note that (Z)9-16 acyl-CoA can be
formed through two alternative routes. The compounds present in the
pheromone glands of H. subflexa are in grey boxes.