Docosahexaenoic acid 1,2,3,4-¹³C (DHA 1,2,3,4-¹³C) is intended for use as an internal standard for the quantification of DHA by GC- or LC-MS. DHA is a long-chain ω-3 polyunsaturated fatty acid (PUFA) found in fish and algal oils.¹It comprises approximately 40% of total brain PUFAs and is abundant in grey matter and retinal membranes.²DHA typically represents 0.52-7.5% of human total plasma fatty acids. It is produced from α-linolenic acidviaa series of desaturase- and elongase-catalyzed reactions, resulting in a docosapentaenoic acid intermediate, which is elongated, desaturated, and β-oxidized to produce DHA.³DHA can be liberated from cellular membranes by phospholipase A₂(PLA₂) and converted to numerous oxylipins, including specialized pro-resolving mediators (SPMs), which are produced by lipoxygenases and include D-series protectins and resolvins, as well as maresins, that regulate host defense and the resolution of inflammation.⁴DHA has roles in several physiological and pathological processes, including neural development, cardiovascular diseases, obesity, and inflammation.^3,5

1.Kuratko, C.N., and Salem, N., Jr.Biomarkers of DHA statusProstaglandins Leukot. Essent. Fatty Acids81(2-3)111-118(2009) 2.Lacombe, R.J.S., Chouinard-Watkins, R., and Bazinet, R.P.Brain docosahexaenoic acid uptake and metabolismMol. Aspects Med.64109-134(2018) 3.Calder, P.C.Docosahexaenoic acidAnn. Nutr. Metab.69(Suppl 1)7-21(2016) 4.Basil, B.C., and Levy, B.D.Specialized pro-resolving mediators: Endogenous regulators of infection and inflammationNat. Rev. Immunol.16(1)51-67(2016) 5.Arnoldussen, I.A.C., and Kiliaan, A.J.Impact of DHA on metabolic diseases from womb to tombMar. Drugs12(12)6190-6212(2014)