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Characterization of a Phospholipid Adduct Formed in Sprague Dawley Rats by Chloroform Metabolism: NMR Studies
Author(s) -
Guastadisegni Cecilia,
Guidoni Laura,
Balduzzi Maria,
Viti Vincenza,
Consiglio Emma Di,
Vittozzi Luciano
Publication year - 1998
Publication title -
journal of biochemical and molecular toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.526
H-Index - 58
eISSN - 1099-0461
pISSN - 1095-6670
DOI - 10.1002/(sici)1099-0461(1998)12:2<93::aid-jbt4>3.0.co;2-j
Subject(s) - chloroform , phospholipid , adduct , chemistry , metabolism , characterization (materials science) , biochemistry , organic chemistry , membrane , materials science , nanotechnology
The formation of a covalent adduct to a single phospholipid by the oxidative chloroform metabolite, phosgene, is demonstrated in liver mitochondria of phenobarbital‐pretreated Sprague Dawley (SD) rats treated with CHCl 3 . The densitometric analysis of the phosphorus stained extracted phospholipids showed that the formation of this adduct in liver mitochondria is accompanied by a decrease of phosphatidylethanolamine and cardiolipin. The characterization of this adduct was performed with a multinuclear NMR approach by comparison with the decreased phospholipids. Treatment of rats with [ 13 C]chloroform resulted in an intense 13 C NMR peak from either an esteric or amidic carbonyl. Very strong similarities in fatty acid composition were found between phosphatidylethanolamine and the phosgene‐modified PL, using 13 C and 1 H NMR spectroscopy. A multiplet at 3.91 ppm coupled to a signal at 3.41 ppm was shown by two‐dimensional 1 H NMR in the adduct spectrum. This cross peak was interpreted as arising from the shifted resonances of the two PE head group methylene groups, due to the binding with phosgene. 31 P spectrum of the adduct was identical to that of phosphatidylethanolamine. We concluded that the chloroform adduct is a modified phosphatidylethanolamine, with the phosgene‐derived carbonyl bound to the amine of the head group. © 1997 John Wiley & Sons, Inc. J Biochem Toxicol 12: 93–102, 1998