An Efficient Glycoblotting‐Based Analysis of Oxidized Lipids in Liposomes and a Lipoprotein

Even though the widely occurring lipid oxidation, which is triggered by reactive oxygen species (ROS), produces a variety of oxidized lipids, practical methods to efficiently analyze oxidized lipids remain elusive. Herein, we show that the glycoblotting platform can be used to analyze oxidized lipids. The analysis is based on the principle that lipid aldehydes, one of the oxidized lipid species, can be captured selectively, enriched, and detected. Moreover, we discovered that 3-methyl-1-p-tolyltriazene (MTT) methylates phosphoric and carboxylic acids, and that MTT-mediated methylation is, in combination with conventional tandem mass spectrometry (MS/MS) analysis, an effective method for the structural analysis of oxidized lipids. Using three classes of standards, liposomes, and a lipoprotein, we demonstrate that glycoblotting represents a powerful approach for focused lipidomics even in complex macromolecules.