Interaction of vitamin E and its model compounds with unsaturated fatty acids in homogeneous solution.

Either alpha-tocopherol (vitamin E) or one of its model compounds having side chains of different length at the 2-position of alpha-tocopherol, forms complexes with an unsaturated fatty acid in methanol. For complex formation, the isoprenoid side chain and hydroxy group of alpha-tocopherol are unessential and, rather, the methyl groups attached to the aromatic ring of the chromanol moiety seems to be responsible. For better interaction, more than three methylene-interrupted Z double bonds of a fatty acid are necessary. These findings are incompatible with the hypothesis of Diplock and Lucy on the interaction of vitamin E with each polyunsaturated fatty acid.