Our demonstration
that flies fed a diet supplemented with [1-13C]-palmitic acid led
to the formation of 13C-N-palmitoyldopamine, 13C-N-palmitoylglycine, and 13C-palmitamide is consistent with, but does not prove,
that palmitoyl-CoA in a central palmitoyl donor in the biosynthesis
of the different classes of palmitoylated fatty acid amides. We have
recently identified and characterized an enzyme from D. melanogaster that catalyzes the formation of long-chain N-acylarylalkylamides, notably the N-acylserotonins and the N-acyldopamines,
from the corresponding long-chain acyl-CoA thioesters and aryakylamine: acyl-CoA + serotonin (or dopamine) ? N-acylserotonin
(or N-acyldopamine) + CoA [14]. Importantly, we also found that
the expression pattern of this enzyme in D. melanogaster co-localized to the tissues containing measurable levels of the endogenous
long-chain N-acylserotonins. These data provide evidence for the
central role served by the acyl-CoA thioesters in fatty acid amide
biosynthesis.