Synthesis of a series of polyunsaturated fatty acids, their potencies as essential fatty acids and as precursors of prostaglandins

A series of polyunsaturated fatty acids has been tested on essential fatty acid activity and as precursors of prostaglandins. It was confirmed that biological activity ofall‐cis8,11,14‐trienoates and 5,8,11,14‐tetraenoates is restricted to acids with 19, 20 or 21 carbon atoms.All‐cis8,11,14‐eicosapolyenoates with extra double bonds at positions 2, 3 or 4 are also biologically active, On the other hand, an additional double bond in the ω‐chain of the molecule, e.g. at the 18th position, leads to nearly complete loss of activity.