This high purity fatty acid is ideal as a standard and for biological studies. Eicosanoic acid is present in small amounts in many animals and plants. It is a vital intermediate in the formation of other fatty acids and is formed by the elongation of stearic acid which can then be desaturated to form arachidonic acid and other unsaturated fatty acids. In human amniotic fluid from diabetic humans sphingomyelin was found not to contain any eicosanoic acid but was found in the amniotic fluid of controls.{50600} In the brine shrimp Artemia franciscana sphingomyelin has been found to contain a significant amount of eicosanoic acid although this fatty acid in sphingomyelin is rare in other sources.{50601} Eicosanoic acid has been reported as a significant fatty acid in some plants (such as in peanuts and Sapindaceae) and in some animals (such as in the copepod Temora longicornis). Eicosanoic acid acylated to an amido bile acid has been used to help prevent cholesterol gallstones by acting as a cholesterol solubilizer.{50602}
