Biosynthesis of fatty acids in the roach Eurycotis floridana

After ingestion of [1-¹⁴C]acetate, fatty acids of the roach Eurycotis floridana show a labelling pattern consistent with biosynthesis by condensation of C₂ units. Oleic acid is efficiently synthesized by direct conversion of stearic acid. Synthesis of a C₁₈ dienoic acid may occur at a very low rate. Oleic acid constitutes about half of the total fatty acid content, and palmitic is the most abundant saturated acid. There is only a trace of fatty acids of chain length greater than C₁₈; arachidonic acid is entirely absent.