Abstract
The kinetics of the autoxidation of a series of polyunsaturated fatty acids (PUFA) with increasing degrees of unsaturation and the mono-, di-and triglycerides of linoleate have been studied in homogeneous chlorobenzene solution at 37 C under 760 torr of oxygen. The autoxidations were initiated by thermal decomposition of azo initiators and followed by measuring the rate of oxygen uptake. The rate of chain initiation was determined by the induction period method using α-tocopherol as the chainbreaking antioxidant. The measured oxidizabilities of the PUFA are linearly dependent on the number of doubly allylic positions present in the molecule. Thus, the oxidizability of linoleate is 2.03×10−2 M−1/2 sec−1/2, and the value for docosahexaenoate is five times greater, 10.15×10−2 M−1/2 sec−1/2. The rate of autoxidation for all PUFA studied and for the mono- and diglyceride is proportional to the substrate concentration and to the square root of the rate of chain initiation, implying that the autoxidation of these compounds follows the usual kinetic rate law. The autoxidation of the triglyceride is more complex and does not appear to follow the same rate law at all substrate concentrations. This deviation from the usual kinetic rate expression may be due to lipid aggregation at low concentrations of the triglyceride.
Similar content being viewed by others
References
Tappel, A.L. (1980) inFree Radicals in Biology (Pryor, W.A., ed.) Vol. IV, pp. 1–47, Academic Press, New York.
Pryor, W.A. (1976) inFree Radicals in Biology (Pryor, W.A., ed.) Vol. I, pp. 1–49, Academic Press, New York.
Pryor, W.A. (1984) inFree Radicals in Molecular Biology, Aging and Disease (Armstrong, D., Sohol, R.S., Cutler, R.G., and Slater, T.F., eds.), pp. 13–43, Raven Press, New York.
Barclay, L.R.C., and Ingold, K.U. (1981)J. Am. Chem. Soc. 103, 6478–6485 and references cited therein.
Pryor, W.A., Kaufman, M.J., and Chruch, D.F. (1985)J. Org. Chem. 50, 281–283.
Yamamoto, Y., Niki, E., Eguchi, J., Kamiya, Y., and Shimasaki, H. (1985)Biochim. Biophys. Acta 819, 29–36.
Holman, R.T., and Elmer, O.C. (1947)J. Am. Oil Chem. Soc. 24, 127–129.
Lundberg, W.O. ed. (1961)Autoxidation and Antioxidants, Vols. I and II, Interscience, New York.
Mill, T., and Hendry, D.G. (1990) inChemical Kinetics (Banford, C.H., and Tipper, C.F.H., eds.) pp. 1–83, Elsevier Scientific Publishing, New York.
Maillard, B., Ingold, K.U., and Scaiano, J.C. (1983)J. Am. Chem. Soc. 105, 5095–5099.
Boozer, C.E., Hammond, G.S., Hamilton, C.E., and Sen, J.N. (1955)J. Am. Chem. Soc. 77, 3233–3237.
Burton, G.W., and Ingold, K.U. (1981)J. Am. Chem. Soc. 103, 6472–6477.
Kiefer, H., and Traylor, T.G. (1966)Tetrahedron Lett. 49, 6163–6168.
Howard, J.A., and Ingold, K.U. (1969)Can. J. Chem. 47, 3809–3815.
Yamamoto, Y., Haga, S., Niki, E., and Kamiya, Y. (1984)Bull. Chem. Soc. Jpn. 57, 1260–1264.
Van Hook, J.P., and Tobolsky, A.V. (1958)J. Am. Chem. Soc. 80, 779–782.
Howard, J.A., and Ingold, K.U. (1962)Can. J. Chem. 40, 1851–1864.
Hammond, G.S., Sen, J.M., and Boozer, C.E. (1955)J. Am. Chem. Soc. 77, 3244–3248.
Holman, R.T. (1954) inProgress in the Chemistry of Fats and Other Lipids (Holman, R.T., Lundberg, W.O., and Malkin, T., eds.) Vol. 2, p. 51, Academic Press, New York.
Howard, J.A., and Ingold, K.U. (1967)Can. J. Chem. 45, 793–802.
Anderson, R.E., Maude, M.B., and Nielsen, J.C. (1985)Current Eye Res. 4, 65–71.
Handelman, G.J., and Dratz, E.A. (1986)Adv. Free Radical Biol. Med. 2, 1–89.
Niki, E., Tsuchiyo, J., Yoshokawa, Y., Yamamoto, Y., and Kamiya, Y. (1986)Bull. Chem. Soc. Jpn. 59, 497–501.
Hendry, D.G., and Russell, G.A. (1964)J. Am. Chem. Soc. 86, 2368–2371.
Howard, J.A., and Ingold, K.U. (1966)Can. J. Chem. 44, 1119–1130.
Barclay, L.R.C., MacNeil, J.M., Van Kessel, J., Forrest, B.J. Porter, N.A., Lehman, L.S., Smith, K.J., and Ellington, J.C. (1984)J. Am. Chem. Soc. 106, 6740–6747.
Author information
Authors and Affiliations
About this article
Cite this article
Cosgrove, J.P., Church, D.F. & Pryor, W.A. The kinetics of the autoxidation of polyunsaturated fatty acids. Lipids 22, 299–304 (1987). https://doi.org/10.1007/BF02533996
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02533996