Monoenoic fatty acids in dogfish livers: isomers of the C16, C18, C20, and C22 series.

Abstract

SummaryStructural isomers of monoenoic fatty acids in dogfish (Squalus acanthias) liver oil were determined. These fatty acids comprised 58% of total fatty acids and 87% of unsaturated fatty acids of the oil. Although it is known that polyunsaturated C20 and C22 fatty acids are present in quantity in most fish oils, dogfish-liver oil was found to contain substantial amounts of C20 and C22 monoenoic fatty acids as well. The following isomers were found in the oil: cis-9-hexadecenoic acid (6.1%), cis-9-octadecenoic acid (24.7%), cis-11-octadecenoic acid (9.8%), cis-9-eicosenoic acid (4.0%), cis-11-eicosenoic acid (5.1%), cis-11-docosenoic acid (6.7%), and cis-13-docosenoic acid (1.8%). It is suggested that most of the monoenoic fatty acids of dogfish-liver oil may be formed by addition of acetate units to oleic acid and other fatty acids having a Δ9 double bond.