ω-3 Arachidonic acid is a rare PUFA found in trace amounts in dietary sources. ω-3 Fatty acids are now known to be essential for infant growth and development and protect against heart disease, thrombosis, hypertension, and inflammatory and autoimmune disorders. In human platelet membranes, ω-3 arachidonic acid inhibits arachidonoyl-CoA synthetase with a Ki of 14 µM. It also inhibits arachidonoyl-CoA synthetase in calf brain extracts with an IC50 value of about 5 µM.