Gas chromatographic analysis of reactive carbonyl compounds formed from lipids upon UV-irradiation.
Peroxidation of lipids produces carbonyl compounds; some of these, e.g., malonaldehyde and 4-hydroxynonenal, are genotoxic because of their reactivity with biological nucleophiles. Analysis of the reactive carbonyl compounds is often difficult. The methylhydrazine method developed for malonaldehyde analysis was applied to simultaneously measure the products formed from linoleic acid, linolenic acid, arachidonic acid, and squalene upon ultraviolet-irradiation (UV-irradiation). The photoreaction products, saturated monocarbonyl, alpha,beta-unsaturated carbonyls, and beta-dicarbonyls, were derivatized with methylhydrazine to give hydrazones, pyrazolines, and pyrazoles, respectively. The derivatives were analyzed by gas chromatography and gas chromatography-mass spectrometry. Lipid peroxidation products identified included formaldehyde, acetaldehyde, acrolein, malonaldehyde, n-hexanal, and 4-hydroxy-2-nonenal. Malonaldehyde levels formed upon 4 hr of irradiation were 0.06 micrograms/mg from squalene, 2.4 micrograms/mg from linolenic acid, and 5.7 micrograms/mg from arachidonic acid. Significant levels of acrolein (2.5 micrograms/mg) and 4-hydroxy-2-nonenal (0.17 micrograms/mg) were also produced from arachidonic acid upon 4 hr irradiation.
Dennis
K J
KJ
Department of Environmental Toxicology, University of California, Davis 95616.
Shibamoto
T
T
D000079:Acetaldehyde / Q000032:analysis; D000171:Acrolein / Q000032:analysis; D000447:Aldehydes / Q000032:analysis*; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000737:chemistry / Q000528:radiation effects; D002849:Chromatography, Gas; D005557:Formaldehyde / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000737:chemistry / Q000528:radiation effects; D008042:Linolenic Acids / Q000737:chemistry / Q000528:radiation effects; D015227:Lipid Peroxidation; D008055:Lipids / Q000737:chemistry / Q000528:radiation effects*; D008315:Malondialdehyde / Q000032:analysis; D009002:Monomethylhydrazine; D013185:Squalene / Q000737:chemistry / Q000528:radiation effects; D014466:Ultraviolet Rays
D000447:Aldehydes; D001095:Arachidonic Acids; D008041:Linoleic Acids; D008042:Linolenic Acids; D008055:Lipids; D005557:Formaldehyde; D016718:Arachidonic Acid; D008315:Malondialdehyde; D000171:Acrolein; D013185:Squalene; C010463:n-hexanal; D019787:Linoleic Acid; D000079:Acetaldehyde; C027576:4-hydroxy-2-nonenal; D009002:Monomethylhydrazine