Composition of the Diacyl Glyceryl Ethers and Triglycerides of the Flesh and Liver of the Dogfish (squalus Acanthias).

The major lipids ofthedogfish (Squalusacanthias) are the diacyl glyceryl ethers and triglycerides. These classes of compounds in the flesh (dorsal section) and liver were separated by thin-layer chromatography. The glyceryl ethers and/or fatty acids resulting from saponification of each of these fractions were analyzed by gas-liquid chromatography as their isopropylidene and methyl ester derivatives, respectively. Few significant differences were apparent between the ether portions of the diacyl glyceryl ethers of the flesh and liver, but the fatty acids were quite different in composition. Those of the flesh contained high percentages of the CZ0 and C22 polyenoic acids that are characteristic of most fish lipids; those of the liver contained little polyenoic acid but high concentrations of C ~ O and C22 monoenoic acids. Although the triglycerides of the flesh contained more of the polyenoic acids than the liver, the differences in this fraction between the flesh and liver were less striking. I t appears that the over-all unsaturation of the dogfish lipids is largely governed by the relative amounts of monoenoic and polyenoic acids in the C20 and C22 series.