Journal of Lipid Research, Vol. 12, 214-220, March 1971
Copyright © 1971 by Lipid Research, Inc.

Phospholipids of Clostridium butyricum. IV. Analysis of the positional isomers of monounsaturated and cyclopropane fatty acids and alk-1'-enyl ethers by capillary column chromatography

Howard Goldfine and Charles Panos

Department of Microbiology, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104; and Department of Biochemistry, Albert Einstein Medical Center, Northern Division, Philadelphia, Pennsylvania 19141

The positional isomers of the cyclopropane fatty acids of Clostridium butyricum phospholipids have been analyzed by capillary column gas-liquid chromatography. Greater than 95% of the methylenehexadecanoic acids was the 9,10 isomer. On the other hand, 60-70% of the hexadecenoic acid precursors was the ⁷ isomer, and the remainder was the ⁹ isomer. Of the methyleneoctadecanoic acids 75-80% was the 11,12 isomer, with the remainder being the 9,10 isomer. There were approximately equal amounts of the ⁹- and ¹¹-octadecenoic acids in the phospholipids. This study reveals a surprisingly strong specificity of the cyclopropane synthetase for the (n-7) series of monoenoic fatty acids.

An analysis by capillary column chromatography of the monoenoic and cyclopropane aldehyde dimethylacetals derived from the plasmalogens (1-alk-1'-enyl-2-acyl-glycero-phosphatides) of C. butyricum revealed the presence of the same positional isomeric mixtures of the 16- and 18-carbon monoenoic residues in approximately the same ratios as were found in the fatty acids. In the formation of the cyclopropane alk-1'-enyl ethers there was also specificity for the (n-7) series, but it was not as strong as that seen in the fatty acids. The ratio of the 7,8 isomer to the 9,10 isomer was higher in the methyl-enehexadecanals than in the corresponding fatty acids. This paper extends the use of Golay capillary columns to the analysis of the positional isomers of plasmalogen aldehydes as their dimethylacetal derivatives.

Supplementary key words plasmalogens • aldehydes • cyclopropane synthetase • specificity

Submitted on September 29, 1970
Accepted on November 24, 1970

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