文摘
Nitroalkene fatty acids are potent endogenous ligand activators of PPAR947;-dependent transcription. Previous studies with the naturally occurring regioisomers of nitrolinoleic acid revealed that the isomers are not equivalent with respect to PPAR947; activation. To gain further insight into the structure−activity relationships between nitroalkenes and PPAR947;, we examined additional naturally occurring nitroalkenes derived from oleic acid, 9-nitrooleic acid (E-9-NO2-18:1 [1]) and 10-nitrooleic acid (E-10-NO2-18:1 [2]), and several synthetic nitrated enoic fatty acids of variable carbon chain length, double bonds, and nitration site. At submicromolar concentrations, E-12-NO2 derivatives were considerably more potent than isomers nitrated at carbons 5, 6, 9, 10, and 13, and chain length (16 versus 18) or number of double bonds (1 versus 2) was of little consequence for PPAR947; activation. Interestingly, at higher concentrations (>2 μM) the nitrated enoic fatty acids (E-9-NO2-18:1 [1], E-9-NO2-16:1 [3], E-10-NO2-18:1 [2], and E-12-NO2-18:1 [7]) deviated significantly from the saturable pattern of PPAR947; activation observed for nitrated 1,4-dienoic fatty acids (E-9-NO2-18:2, E-10-NO2-18:2, E-12-NO2-18:2, and E-13-NO2-18:2).