The fatty acids of Euglena gracilis

Abstract

The complete structures of 51 fatty acids of Euglena gracilis have been determined. These include saturated fatty acids from C9 to C19, monounsaturated fatty acids from C13 to C19, diunsaturated fatty acids from C15 to C20, tri-unsaturated fatty acids from C15 to C20, tetraunsaturated fatty acids from C15 to C22, pentaunsaturated fatty acids from C20 to C22, and one docosahexaenoic acid. No evidence was found for branched or cyclic acids. All the double bonds are of the cis-configuration, and the double bonds of polyunsaturated fatty acids are all in methylene-interrupted sequences. E. gracilis synthesizes linoleic acid and linolenic acid, as well as longer chain polyunsaturated fatty acids structurally related to each, thus demonstrating fatty acid biosynthetic mechanisms characteristic of both plants and animals.