8,12-iso-iPF2a-VI-1,5-lactone

F2 isoprostanes (F2-iPs) are thought to arise from the free radical-mediated peroxidation of phospholipid-bound arachidonic acid.{6910} They are cleaved, presumably by an unidentified phospholipase A2, and are found in the circulation and the urine. 8,12-iso-iPF2a-VI-1,5-lactone is a racemic mixture of the lactone forms of the free acid, 8,12-iso- iPF2a-VI. Previously called IPF2a -I,{320} the free acid form, iPF2a-VI, is the most abundant F2-iP regioisomer measured in the urine of rats treated with CCl4 to induce lipid peroxidation.{5603} iPF2a-VI is the only regioisomer that undergoes lactonization, and this occurs slowly in vivo or can be driven chemically.{17353} The less polar lactone is readily separated from the free acid forms of iPF2a.{17353} While the level of iPF2a-VI in plasma, urine and organs is used as a biomarker for oxidative stress,{17354,17355} some F2-iPs also evoke significant biological effects.{16559} It is not known if 8,12-iso-iPF2a-VI-1,5-lactone has important physiological effects.