Purity >98%. Oleic acid is a monounsaturated fatty acid and is one of the major components of membrane phospholipids. It contributes about 17% of the total fatty acids esterified to phosphatidylcholine in porcine platelets. Oleic acid ethyl ester is a neutral, more lipid-soluble form of oleic acid. As the free acid, it inhibits collagen-stimulated platelet aggregation by approximately 90% at a concentration of 10 μg/ml. It inhibits fMLF-induced neutrophil aggregation and degranulation by 55% and 68%, respectively, at 5 μM. Oleic acid, whether applied extracellularly (EC50 = ~60 μM) to human platelets or released from membrane phospholipids, causes an increase in intracellular calcium levels.