(5Z,14Z)-5,14-Eicosadienoic Acid, is a polysaturated fatty acid. Eicosadienoic acids are converted by desaturases, in vivo, to eicosatrienoic acids, which are potent vasodilators. The more common 11(Z),14(Z)-eicosadienoic acid competitively inhibits inosine 5’-monophosphate dehydrogenase (Ki = 3.1 µM)1 and inhibits the binding of LTB4 to its receptor on neutrophils (Ki = 3.0 µM).