[Authenticity discrimination for Galli Gigerii Endothelium Corneum based on UPLC-MS/MS and peptidomics]

Peptidomics was employed to systematically analyze the characteristic peptides in Galli Gigerii Endothelium Corneum and its adulterants and establish a method for distinguishing Galli Gigerii Endothelium Corneum from its adulterants, including the gizzard membranes from ducks, geese, and pigeons. UPLC-Q-Exactive Orbitrap-MS was combined with multivariate statistical analysis to analyze the peptides in Galli Gigerii Endothelium Corneum and its adulterants. The structures of peptides were identified by pNovo combined with manual recognition of spectra, and synthetic peptide standards were used for validation. LC-MS/MS was used to optimize the sample pre-processing conditions, including the extraction procedure, extraction time, extraction solvents, and solvent volumes, for the characteristic peptide LESY in Galli Gigerii Endothelium Corneum. Multiple reaction monitoring(MRM) in the ESI~+ mode with m/z 511.24→269.11 and 511.24→243.13 as detection ions was employed for qualitative and quantitative analyses. The established UPLC-MS/MS method demonstrated good specificity, stability, and durability. The content of LESY in 16 batches of Galli Gigerii Endothelium Corneum samples ranged from 55.03 to 113.36 μg·g~(-1). Additionally, a qualitative detection method for the common peptide RDPVLVSR in adulterants was established with m/z 471.28→785.45 and 471.28→670.41 as the detection ions. This study established a convenient, rapid, and accurate detection method for the characteristic peptides in Galli Gigerii Endothelium Corneum and its adulterants. The method possesses good specificity, stability, and durability, providing a valuable reference for the identification and quality control of Galli Gigerii Endothelium Corneum and other traditional Chinese medicines derived from animal sources.