|DORCHMAN, DOUG - UNIVERSITY OF LOUISVILLE
Submitted to: Journal of Lipid Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/11/1997
Publication Date: N/A
Interpretive Summary: New methods are required for the analysis and determination of phospholipids, a class of fatty compounds which are important components throughout the body. We have developed a new technique for separating and identifying these fatty compounds that permits identification of a previously unidentified component of the phospholipids. This new technique is important to researchers trying to understand how the body uses dietary fat.
Technical Abstract: The identity of the major phospholipid component of human lens membrane extracts, referred to as the unknown phospholipid, was recently proposed to be 4,5-dihydrosphingomyelin. This tentative identification has awaited further analytical characterization. Using high performance liquid chromatographic separation with atmospheric pressure chemical ionization and electrospray ionization mass spectrometric detection, we report here the first unambiguous identification of the molecular species of the unknown phospholipid. The most abundant molecular species were tetracosenoic (24:1) and palmitic 4,5-dihydrosphingomyelins. Lesser amounts of hexacosanoic, hexacosenoic, tetracosanoic, docosanoic, docosenoic, stearic and myristic dihydrosphingomyelins were found. The most abundant sphingomyelin molecular species in the human lens were similar to those of dihydrosphingomyelin. Commercially available egg yolk sphingomyelin was also found to contain significant amounts of dihydrosphingomyelin species. Molecular species of phosphatidylcholine and cholesterol esters were also identified.