Novel carbonyl and nitrile products from reactive chlorinating species attack of lysosphingolipid

Lysosphingolipids are important lipid signaling molecules that are associated predominantly with high density lipoproteins (HDL) in human plasma. Further, HDL has been shown to be a target for the reactive chlorinating species (RCS) produced by myeloperoxidase (MPO). Accordingly, RCS attack of lysosphingolipids was characterized in these studies. It was shown that RCS attack of sphingosylphosphorylcholine results in the formation of 2-hexadecenal and 1-cyano methano phosphocholine. The structures were identified and confirmed predominantly using mass spectrometric analyses. Further, it was demonstrated that RCS attack of another bioactive lysosphingolipid sphingosine 1-phosphate also results in the formation of 2-hexadecenal from its sphingosine base. Using a synthetically prepared, deuterated 2-hexadecenal internal standard, it was determined that 2-hexadecenal quickly accumulated in HDL treated with MPO/RCS generating system. Thus, the present studies characterize the formation of a novel group of lipid products generated following RCS attack of lysosphingolipids.