Synthesis of 9-and 12-nitro conjugated linoleic acid: Regiospecific isomers of naturally occurring conjugated nitrodienes

Conjugated diene-containing fatty acids (rumenic and rumelenic acids) are major substrates for nitration under physiological conditions. Their nitrated products are present in human urine. These nitrodienecontaining lipid electrophiles contain a strongly electron-withdrawing pair of conjugated double bonds amenable to nucleophilic attack in biological milieu, which affords them pluripotent signaling capabilities. We report synthetic methods to obtain useful quantities of three main biological nitrated fatty acids (9-and 12-nitro-conjugated linoleic acids and 9-nitro-conjugated linolenic acid) in six or seven steps from commercially available starting materials, for biological evaluation of these naturally occurring biomolecules. (C) 2021 Published by Elsevier Ltd.