Isofurans are nonclassic eicosanoid

Nonclassic eicosanoid

Nonclassic eicosanoids are biologically active signaling molecules made by oxygenation of twenty-carbon fatty acids other than the classic eicosanoids.-Terminology:"Eicosanoid" is the collective...

s formed nonenzymatically by free radical mediated peroxidation of arachidonic acid

Arachidonic acid

Arachidonic acid is a polyunsaturated omega-6 fatty acid 20:4.It is the counterpart to the saturated arachidic acid found in peanut oil, Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega-6 fatty acid 20:4(ω-6).It is the counterpart to the saturated arachidic acid found in peanut oil,...

. The isofurans are similar to the isoprostane

Isoprostane

The isoprostanes are prostaglandin-like compounds formed in vivo from the free radical-catalyzed peroxidationof essential fatty acids without the direct action of cyclooxygenase enzyme....

s and are formed under similar conditions, but contain a substituted tetrahydrofuran

Tetrahydrofuran

Tetrahydrofuran is a colorless, water-miscible organic liquid with low viscosity at standard temperature and pressure. This heterocyclic compound has the chemical formula 4O. As one of the most polar ethers with a wide liquid range, it is a useful solvent. Its main use, however, is as a precursor...

ring. The concentration of oxygen affects this process; at elevated oxygen concentrations, the formation of isofurans is favored whereas the formation of isoprostanes is disfavored.