9-Nitrooleate is one of two regioisomers of nitrooleic acid, the other being 10-nitrooleic acid (OA-NO2, used for the mixture of isomers), are formed by nitration of oleic acid in approximately equal proportions. Peroxynitrite, acidified nitrite, and myeloperoxidase, in the presence of H2O2 and nitrite, all mediate the nitration of oleic acid. OA-NO2 is found in human plasma as the free acid and esterified in phospholipids at concentrations of 619 ± 52 nM and 302 ± 369 nM, respectively. OA-NO2 activates PPARγ approximately 7-fold at a concentration of 1 M and effectively promotes differentiation 3T3-L1 preadipocytes to adipocytes at 3 M.
