Epoxidation of plasmalogens: Source for long-chain α-hydroxyaldehydes in subcellular fractions of bovine liver

Abstract

1. Masked long-chain α-hydroxyaldehydes were trapped in all subcellular fractions of bovine liver by application of pentafluorbenzyloxime derivatization and quantified via GLC/MS using characteristic ion traces. 2. The chain-length profile of long-chain 2-hydroxy-alkanales clearly indicates their relationship to plasmalogens as precursor molecules. 3. The previously postulated existence of α-acyloxyplasmalogens as precursor molecules of masked longchain α-hydroxyaldehydes in bovine tissue lipids was excluded. 4. The constant oxidation rate of plasmalogens in all subcellular fractions provides conclusive evidence for a non-enzymic plasmalogen epoxidation process (probably via hydroperoxy radicals). 5. The high reactivity of α-hydroxyaldehydes sheds some doubt on the postulation that plasmalogens protect mammalian cells against oxidative stress as postulated previously.