The unsaturated fatty acyl moieties of TAG present in natural oils of borage, olive, and rice were converted to their corresponding geometrical trans isomers by thiyl radical-catalyzed isomerization. Thiyl radicals were generated from 2-mercaptoethanol under photolytic or thermal conditions. A relevant feature of this method is the absence of double-bond shifts, so that no positional trans isomers or conjugated polyenes are formed. Oils obtained after the isomerization were winterized to further increase their trans fatty acid content. Methanolysis and hydrolysis of the trans oil mixtures using an enzymatic method (lipase B from Candida antarctica) gave good conversions to the corresponding trans FAME and fatty acids, respectively. These results are relevant for the studies of lipid isomerism and trans fatty acid recognition, which is a growing concern in biochemistry and nutrition, and open new perspectives for the synthesis of glycerides and studies of their structure-activity relationships.
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Aro, A., Epidemiological Studies of trans Fatty Acids and Coronary Heart Disease, in Trans Fatty Acids in Human Nutrition, edited by J.L. Sébédio and W.W. Christie, The Oily Press, Dundee, 1998, pp. 235–260.
McDonald, R.E., and M.M. Mossoba, Methods for trans Fatty Acid Analysis, in Food Lipids: Chemistry, Nutrition and Biotechnology, edited by C.C. Akoh and D.B. Min, Marcel Dekker, New York, 2002, pp. 169–204.
Lie Ken Jie, M.S.F., and C.C. Lam, 1H-Nuclear Magnetic Resonance Spectroscopic Studies of Saturated, Acetylenic and Ethylenic Triacylglycerols, Chem. Phys. Lipids 77:155–171 (1995).
Lie Ken Jie, M.S.F., and J. Mustafa, High-Resolution Nuclear Magnetic Resonance Spectroscopy—Applications to Fatty Acids and Triacylglycerols, Lipids 32:1019–1035 (1997).
Sgoutas, D.S., and F.A. Kummerow, Cis-trans Isomerization of Unsaturated Fatty Acid Methyl Esters Without Double Bond Migration, 4:283–287 (1969).
Ferreri, C., C. Costantino, L. Perrotta, L. Landi, Q.G. Mulazzani, and C. Chatgilialoglu, Cis-trans Isomerization of Polyunsaturated Fatty Acid Residues in Phospholipids Catalyzed by Thiyl Radicals, J. Am. Chem. Soc. 123:4459–4468 (2001).
Ferreri, C., A. Samadi, F. Sassatelli, L. Landi, and C. Chatgilialoglu, Regioselective cis-trans Isomerization of Arachidonic Double Bonds by Thiyl Radicals: The Influence of Phospholipid Supramolecular Organization, 126:1063–1072 (2004).
Ferreri, C., M.R. Faraone-Mennella, C. Formisano, L. Landi, and C. Chatgilialoglu, Arachidonate Geometrical Isomers Generated by Thiyl Radicals: The Relationship with trans Lipids Detected in Biological Samples, Free Radic. Biol. Med. 33:1516–1526 (2002).
Shimada, Y., Y. Watanabe, T. Samukawa, A. Sugihara, H. Noda, H. Fukuda, and A. Tominaga, Conversion of Vegetable Oil to Biodiesel Using Immobilized Candida antarctica Lipase, J. Am. Oil Chem. Soc. 76:789–793 (1999).
Borgdorf, R., and S. Warwel, Substrate Selectivity of Various Lipases in the Esterification of cis- and trans-9-Octadecenoic Acid, Appl. Microb. Biotechnol. 51:480–485 (1999).
Jaworski, J., and E.B. Cahoon, Industrial Oils from Transgenic Plants, Curr. Opin. Plant Biol. 6:178–184 (2003).
Grandgirard, A., A. Piconneaux, J.L. Sébédio, and F. Julliard, Trans Isomers of Long-Chain n−3 Polyunsaturated Fatty Acids in Tissue Lipid Classes of Rats Fed with Heated Linseed Oil, Reprod. Nutr. Dev. 38:17–29 (1998).
Huang, X., and C. Fang, Dietary trans Fatty Acids Increase Hepatic Acyl-CoA: Cholesterol Acyltransferase Activity in Hamsters, Nutr. Res. 20:547–558 (2000).
Kramer, J.K.C., V. Fellner, M.E.R. Dugan, F.D. Sauer, M.M. Mossoba, and M.P. Yurawecz, Evaluating Acid and Base Catalysis in the Methylation of Milk and Rumen Fatty Acids with Special Emphasis on Conjugated Dienes and Total trans Fatty Acids, Lipids 32:1219–1228 (1997).
Wolff, R.I., and D. Precht, A Critique of 50-m CP-Sil 88 Capillary Columns Used Alone to Assess trans-Unsaturated FA in Foods: The Case of the TRANSFAIR Study, 37:627–629 (2002).
Official Methods and Recommended Practices of the AOCS, edited by D. Firestone, 5th edn., AOCS Press, Champaign, 1998.
Chatgilialoglu, C., C. Ferreri, M. Ballestri, Q.G. Mulazzani, and L. Landi, Cis-trans Isomerization of Monounsaturated Fatty Acid Residues in Phospholipids by Thiyl Radicals, J. Am. Chem. Soc. 122:4593–4601 (2000).
Chatgilialoglu, C., A. Altieri, and H. Fischer, The Kinetics of Thiyl-Radical Induced Reactions of Monounsaturated Fatty Acid Esters, 124:12816–12823 (2002).
Loliger, J., P. Lambelet, R. Aeschbach, and E. Prior, Natural Antioxidants: From Radical Mechanisms to Food Stabilization, in Food Lipids and Health, edited by R.E. McDonald and D.B. Min, Marcel Dekker, New York, 1996, pp. 68–77.
Chatgilialoglu, C., L. Zambonin, A. Altieri C. Ferreri, Q.G. Mulazzani, and L. Landi, Geometrical Isomerism of Monounsaturated Fatty Acids. Thiyl Radical Catalysis and Influence of Antioxidant Vitamins, Free Radic. Biol. Med. 33:1143–1147 (2002).
Warwel, S., R. Borgdorf, and L. Brühl, Substrate Selectivity of Lipases in the Esterification of Oleic Acid, Linoleic Acid, Linolenic Acid and Their All-trans-Isomers and in the Transesterification of cis/trans-Isomers of Linoleic Acid Methyl Ester, Biotechnol. Lett. 21:431–436 (1999).
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Samadi, A., Andreu, I., Ferreri, C. et al. Thiyl radical-catalyzed isomerization of oils: An entry to the trans lipid library. J Amer Oil Chem Soc 81, 753–758 (2004). https://doi.org/10.1007/s11746-004-0974-8
- Geometrical isomerization
- thiyl radicals
- trans fatty acids
- trans oils