Comprehensive characterization of the chemical constituents in Platycodon grandiflorum by an integrated liquid chromatography-mass spectrometry strategy

Platycodon grandiflorum (PG), as a well-known medicine food homology species, possess various pharmacological effects and health benefits. Aiming to facilitate in-depth and global characterization of the chemical compositions of PG, a profiling method based on ultra-high performance liquid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry (UPLC/IM-QTOF-MS) was conducted. Consequently, as many as 187 compounds were plausibly or unambiguously identified. Most importantly, phospholipids (PLs) were first observed and identified in PG. Due to their widely confirmed bioactivities, an analysis scheme was developed by hydrophilic interaction liquid chromatography and electrospray ionization tandem mass spectrometry combined with the online Paternò-Büchi reaction (HILIC-PB-MS/MS). The fatty acyl chains and C=C locations of 180 PLs molecular species, which fell into four classes, were unprecedently characterized. This exposure strategy of multi-type constituents greatly enriches the chemical profiling of PG, and helps promoting the further development of therapeutic agents and nutraceutical products from PG.

• This study presents a profiling approach of chemical compositions in Platycodon grandiflorum using ultra-high performance liquid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry (UPLC/IM-QTOF-MS), and more importantly, an analysis workflow combined hydrophilic interaction liquid chromatography-electrospray ionization tandem mass with online Paternò-Büchi reaction (HILIC-PB-MS/MS) for the C=C location determination.
• 180 lipids including 4 classes of distinct phospholipids were newly identified down to the levels of fatty acyl chain and C = C location, revealing phospholipids as critical bioactive components in Platycodon grandiflorum.