Identification of Double Bond Positions and Relative Acyl Chain Positions in Egg Yolk Phosphatidylcholines Using OAD-TOF System

User Benefits

- Position-specific fragmentation with the OAD RADICAL SOURCE I allows the identification of double bond positions. - Relative acyl chain position assigned using sn-1 signature ions produced by sequential CID and OAD is possible. - Fragment ions are detected with high mass accuracy and structure characterization is annotated with high certainty.

Introduction

As a major class of lipids, phosphatidylcholines (PCs) often contain mixtures of structural isomers in terms of relative acyl chain positions on the glycerol backbone (sn-positions) and the locations of carbon-carbon double bonds (C=Cs) in unsaturated acyl chains. Studies have revealed these structural diversity has deep impacts on cell membrane permeability, proteins binding, enzyme selectivity, and plasticity of cancer cells. However, profiling PC isomers at the aforementioned level remains challenging as any relating variation structural isomers cannot be differentiated by traditional CID. In this Application News, we present a novel workflow for confidently profiling PCs down to sn-- and C=C location level. This proposed method can be simply incorporated into liquid chromatography coupled with OAD-TOF system without sample derivatization or any instrument modification. The performance of the workflow is demonstrated by identification of 24 distinct PC molecular species from the egg yolk sample, including 8 identified down to C=C level only and 4 to both.

February 3, 2026 GMT