9,12-Octadecadiynoic Acid is a plant lipoxygenase inhibitor. 9,12-Octadecadiynoic Acid is a linoleic acid metabolism inhibitor. 9,12-Octadecadiynoic Acid stimulates the antigen-induced contraction of guinea-pig tracheal spirals and the immunological release of slow reacting substance of anaphylaxis (SRS-A) from actively sensitized guinea-pig lung fragments.