ACYL AND ALK‐1′‐ENYL GROUP COMPOSITION OF ETHANOLAMINE PHOSPHOGLYCERIDES OF HUMAN BRAIN

Abstract

Abstract— Ethanolamine phosphogylcerides (EPG) of human brain gray and white matter were analyzed for their alk‐1′‐enyl group and fatty acid compositions in sn‐glycerol positions 1 and 2. Gray matter contained more 18:0 (54%) and less 18:1 (24.5%) alk‐1′‐enyl residues than white matter (16% and 57%. Sixty per cent of alk‐1′‐enyl 18.1 in gray matter was the (n‐7), against 71%, in white matter. Both gray and white matter contained small amounts of 18:1 (n‐5) and (n‐3) isomers. The fatty acids in position I of the phosphatidylethanolamines were more saturated than the corresponding alk‐1′‐enyl groups of the plasmalogens. The ratios of monoenoic fatty acid isomers in position 1 were markedly different from those of the corresponding alk‐1′‐enyl groups in gray matter. The fatty acid patterns in position 2 of plasmalogen and phosphatidylethanolamines of white matter were similar except for 22:4(n‐6) which was concentrated in the plasmalogen (16% against 10%, in the phosphatidyl ethanolamine). In gray matter, the same trend was noted. The data suggest that alk‐1′‐enyl residues and the fatty acids in position 1 as well as the fatty acids in position 2 of alk‐1′‐enyl acyl and diacyl type EPG in both gray and white matter are, at least in part, of different provenance.