Vitamin A and glutathione-mediated free radical damage: competing reactions with polyunsaturated fatty acids and vitamin C.
Vitamin A (retinol reacts extremely rapidly (k = 1.4 x 10(9) M-1 s-1) with thiyl free radicals derived from glutathione to form a free radical with a very strong visible absorption (lambda max. = 380 nm, E max. = 4.0 x 10(4) M-1 cm-1). Arachidonate, linolenate, linoleate and ascorbate also react readily but much more slowly (k = 2.2 x 10(7), 1.9 x 10(7), 1.3 x 10(7) and 3.6 x 10(8) M-1 s-1 respectively). These results support the possibility that vitamin A might play a role in protecting lipid membranes against thiyl free radical mediated damage.
D'Aquino
M
M
National Institute of Nutrition, Roma, Italy.
Dunster
C
C
Willson
R L
RL
D016718:Arachidonic Acid; D001095:Arachidonic Acids; D001205:Ascorbic Acid; D005231:Fatty Acids, Unsaturated; D005609:Free Radicals; D005978:Glutathione; D007700:Kinetics; D019787:Linoleic Acid; D008041:Linoleic Acids; D008042:Linolenic Acids; D013329:Structure-Activity Relationship; D014801:Vitamin A; D017962:alpha-Linolenic Acid
D001095:Arachidonic Acids; D005231:Fatty Acids, Unsaturated; D005609:Free Radicals; D008041:Linoleic Acids; D008042:Linolenic Acids; D017962:alpha-Linolenic Acid; D014801:Vitamin A; D016718:Arachidonic Acid; D019787:Linoleic Acid; D005978:Glutathione; D001205:Ascorbic Acid