le to modulate the metabolism of polyunsaturated fatty acids and alter the responsiveness of macrophages to inflammatory stimulations.2 Along with other mono and polyunsaturated fatty acids cis-11,14-eicosadienoic acid can inhibit the binding of leukotriene B4 to pig neutrophil membranes, which may account in part for it’s anti-inflammatory activities.3 The X-ray powder diffraction pattern of the sodium soap of cis-11,14-eicosadienoic acid is typical of the crystalline lamellar phase.4