4-hydroxy Nonenal is a lipid peroxidation product derived from oxidized ω-6 polyunsaturated fatty acids such as arachidonic acid and linoleic acid. [1] [2] It exhibits various biological activities such as cytotoxicity, growth inhibiting activity, genotoxicity, and chemotactic activity and has been widely used as a marker of lipid peroxidation.[1][2][3] 4-oxo-2-Nonenal is a more recently identified product of lipid peroxidation.[4][5][6] It actively modifies histidine and lysine residues on proteins and causes protein cross-linking. [7][8] 4-oxo-2-Nonenal also modifies 2’-deoxyguanosine, further implicating lipid peroxidation in mutagenesis and carcinogenesis.[4]

Reference:
[1]. Pryor, W.A., and Porter, N.A. Suggested mechanisms for the production of 4-hydroxy-2-nonenal from the autoxidation of polyunsaturated fatty acids. Free Radical Biology & Medicine 8, 541-543 (1990).
[2]. Esterbauer, H., Schaur, R.J., and Zoliner, H. Chemistry and biochemistry of 4-hydroxynonenal, malonaldehyde, and related aldehydes. Free Radical Biology & Medicine 11, 81-128 (1991).
[3]. Sodum, R.S., and Chung, F.L. 1,N2-ethenodeoxyguanosine as a potential marker for DNA adduct formation by trans-4-hydroxy-2-nonenal. Cancer Research 48, 320-323 (1988).
[4]. Rindgen, D., Nakajima, M., Wehrli, S., et al. Covalent modifications to 2'-deoxyguanosine by 4-oxo-nonenal, a novel product of lipid peroxidation. Chemical Research in Toxicology 12, 1195-1204 (1999).
[5]. Lee, S.H., and Blair, I.A. Characterization of 4-oxo-2-nonenal as a novel product of lipid peroxidation. Chemical Research in Toxicology 13, 698-702 (2000).
[6]. Spiteller, P., Kern, W., Reiner, J., et al. Aldehydic lipid peroxidation products derived from linoleic acid. Biochimica et Biophysica Acta 1531, 188-208 (2001).
[7]. Liu, Z., Minkler, P.E., and Sayre, L.M. Mass spectroscopic characterization of protein modification by 4-hydroxy-2-(E)-nonenal and 4-oxo-2-(E)-nonenal. Chemical Research in Toxicology 16, 901-911 (2003).
[8]. Zhang, W.H., Liu, J., Xu, G., et al. Model studies on protein side chain modification by 4-oxo-2-nonenal. Chemical Research in Toxicology 16, 512-523 (2003).