title: Confirmation of the identity of the major phospholipid in human lens membranes.
abstract: OBJECTIVE
  To confirm the identity of the major component of the human lens membranes proposed in 1994 to be dihydrosphingomyelin (DH-SPH).
  
  
  METHODS
  DH-SPH was prepared by catalytic hydrogenation of the double bond between carbons 4 and 5 of sphingomyelin (SPH). DH-SPH was characterized by phosphorus-31 (31P) and proton (1H) nuclear magnetic resonance (NMR) spectroscopy at different reaction times. The spectroscopic data were compared to those of the major component extracted from human lens membranes.
  
  
  RESULTS
  Both the 1H NMR and the 31P NMR spectral resonances of the prepared DH-SPH matched those for the once "unknown phospholipid" that constitutes approximately half the human lens phospholipids.
  
  
  CONCLUSIONS
  The match of the spectroscopic NMR data obtained for the DH-SPH prepared by hydrogenation of SPH and those for the major phospholipid isolated from the human lens membranes confirms the identity of this sphingolipid as D-erythro-4,5-dihydrosphingomyelin.
authors.affiliation: Department of Chemistry, Kentucky Lions Eye Research Institute, University of Louisville 40292, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Ferguson
authors.forename: D
authors.initials: D
authors.lastname: Borchman
authors.forename: M C
authors.initials: MC
authors.lastname: Yappert
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry; D006801:Humans; D006865:Hydrogenation; D007908:Lens, Crystalline / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008563:Membrane Lipids / Q000032:analysis* / Q000302:isolation & purification; D010743:Phospholipids / Q000032:analysis / Q000302:isolation & purification; D013109:Sphingomyelins / Q000032:analysis* / Q000302:isolation & purification
chemical_list: C091181:4,5-dihydrosphingomyelin; D008563:Membrane Lipids; D010743:Phospholipids; D013109:Sphingomyelins