Rate constants for peroxidation of polyunsaturated fatty acids and sterols in solution and in liposomes.

ABSTRACT: Rate constants for autoxidation propagation of several unsaturated lipids in benzene solution at 37 degrees C and in phosphatidylcholine liposomes were determined by a linoleate radical clock. This radical clock is based on competition between hydrogen atom abstraction by an intermediate peroxyl radical derived from linoleic acid that leads to a trans,cis-conjugated hydroxyoctadecadienoic product and beta-fragmentation of the same peroxyl that gives the trans,trans-product hydroxyoctadecadienoic acid. Rate constants determined by this approach in solution relative to linoleic acid (k(p) = 62 M(-1) s(-1)) were: arachidonic acid (k(p) = 197 +/- 13 M(-1) s(-1)), eicosapentaenoic acid (k(p) = 249 +/- 16 M(-1) s(-1)), docosahexaenoic acid (k(p) = 334 +/- 37 M(-1) s(-1)), cholesterol (k(p)= 11 +

SUBMITTER: Xu L 

PROVIDER: S-EPMC3656724 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature