Separation of isomeric lysophospholipids by reverse phase HPLC

A reverse‐phase high performance liquid chromatography (HPLC) method was developed which resolved isomers of lysophosphatidylcholine (LPC) differing in the location of the aliphatic chain (sn‐1 orsn‐2 position) and the position (Δ6 or Δ9) or geometric configuration (cis ortrans) of the olefin group in monounsaturated species. LPC isomers containing an acyl substituent at thesn‐2 position eluted before their 1‐acyl‐sn‐glycero‐3‐phosphocholine (1‐acyl LPC) counterparts. The retention times of both thesn‐1 andsn‐2 isomers of monounsaturated species increased in the order Δ9‐cis < Δ9‐trans < Δ6‐cis. The integrated ultraviolet absorbance (203 nm) in binary mixtures of the Δ9‐cis and Δ6‐cis 2‐acyl lysophospholipid isomers correlated with the lipid phosphorus content of corresponding column eluates (r‐0.994). Thus, the present method will facilitate synthesis of isomerically pure diradylphospholipids by providing homogeneous lysophospholipid precursors and help simplify the quantitative analysis of unsaturated lysophospholipid species.