High-performance liquid chromatographic method for determination of the metabolism of polyunsaturated molecular species of phosphatidylserine labeled in the polar group.

A reversed-phase HPLC method to monitor the incorporation of radiolabeled precursors into the polar group of individual polyunsaturated molecular species of phosphatidylserine (PS) is presented. PS labeled in the polar group was decarboxylated and subsequently converted to trinitrophenyl-phosphatidylethanolamine (Tnp-PE), which was separated into its molecular species by reversed-phase HPLC within 90 min, using a gradient of acetonitrile-methanol and ammonium acetate. A major feature of the method is the complete resolution of the stearoyl species, 18:0/20:4 and 18:0/22:6, at ambient temperature. By determining the amount of radioactivity incorporated into each fraction, the metabolism of individual molecular species of PS, and also of PE, labeled in the polar group can be investigated.