Arachidonic acid (Icosanoic acid), a long-chain fatty acid, is present in all mammalian cells, typically esterified to membrane phospholipids, and is one of the most abundant polyunsaturated fatty acids present in human tissue[1][2]. Human Endogenous Metabolite
[1]. KoppovÁ I, et al. Analysis of fatty acid composition of anaerobic rumen fungi. Folia Microbiol (Praha). 2008;53(3):217-20. [2]. Martin SA, et al. The discovery and early structural studies of arachidonic acid. J Lipid Res. 2016 Jul;57(7):1126-32.