A. Loidlstahlhofen et al., EPOXIDATION OF PLASMALOGENS - SOURCE FOR LONG-CHAIN ALPHA-HYDROXYALDEHYDES IN SUBCELLULAR-FRACTIONS OF BOVINE LIVER, Biochemical journal, 309, 1995, pp. 807-812
1. Masked long-chain alpha-hydroxyaldehydes were trapped in all subcel
lular fractions of bovine liver by application of pentafluorbenzyloxim
e derivatization [van Kuijk, Thomas, Stephens and Dratz (1986) Biochem
. Biophys. Res. Commun. 139, 144-149] and quantified via GLC/MS using
characteristic ion traces. 2, The chain-length profile of long-chain 2
-hydroxyalkanales clearly indicates their relationship to plasmalogens
as precursor molecules. 3. The previously postulated existence of alp
ha-acyloxyplasmalogens as precursor molecules of masked long-chain alp
ha-hydroxyaldehydes in bovine tissue lipids [Lutz and Spiteller (1991)
Liebigs Ann. Chem. 1998, 563-567] was excluded. 4. The constant oxida
tion rate of plasmalogens in all subcellular fractions provides conclu
sive evidence for a non-enzymic plasmalogen epoxidation process (proba
bly via hydroperoxy radicals). 5. The high reactivity of alpha-hydroxy
aldehydes sheds some doubt on the postulation that plasmalogens protec
t mammalian cells against oxidative stress as postulated previously [M
orand, Zoeller and Raetz (1988) J. Biol. Chem. 263, 11590-11596; Moran
d, Zoeller and Raetz (1988) J. Biol. Chem. 263, 11597-11606].