Molecular networking and Paterno-Büchi reaction guided glycerides characterization and antioxidant activity...

Ganoderma lucidum spore oil (GLSO) is a dietary supplement, with glycerides (GLs) recognized as its important active component. However, comprehensive profiling and accurate structural characterization of GLs in GLSO remain underexplored. In this study, 59 GLs from GLSO were identified by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF MS) and molecular networking (MN). The double bond isomers of these compounds were further resolved by the Paterno-Büchi (PB) reaction coupled with UPLC-Q-TOF MS, resulting in the identification of 36 unsaturated GLs, including 5 pairs of positional isomers. In summary, 64 GLs were characterized, consisting of 9 diacylglycerols (DGs) and 55 triacylglycerols (TGs). Additionally, the compositional variations, antioxidant activities, and relative isomer ratios of CC positional isomers of GLSO from eight different manufacturers were revealed, with 11 GLs correlating with antioxidant activity. This study enhances the understanding of the nutritional value of GLSO and lays a foundation for future quality standard formulation.