Purity >90%. Arachidonic acid is an essential fatty acid and a precursor for all prostaglandins, thromboxanes, and leukotrienes. Arachidonic Acid Alkyne is a form of arachidonic acid with an ?-terminal alkyne. The terminal alkyne group can be used in click chemistry linking reactions to tag arachidonic acid with fluorescent or biotinylated labels for analysis of its metabolism and biological activity. Because the alkyne group is at the ?-terminus, this compound can be used to easily tag metabolites and derivatives.