Quality Evaluation of the Root Bark Epidermis of Peony by HPLC-DAD-ESI-MS/MS

The annual output of Moutan Cortex is significant, but the epidermis of the root bark of peony (EPRP), as a by-product of Moutan Cortex, is typically discarded. To achieve full use of resources, this study aimed to develop an HPLC fingerprint analysis method using HPLC-DAD-ESI-MS/MS on EPRP sourced from different regions to establish EPRP quality control standards. For chromatography, a ShimPack Scepter C₁₈ column (4.6 mm × 250 mm, 5 μm) was used. The mobile phase for HPLC consisted of acetonitrile (A) and a 0.1% aqueous formic acid solution (B). An HPLC fingerprint was established, featuring 30 characteristic peaks with a similarity of over 0.80. A total of 31 components were identified, with 22 chemical markers determined, including 1-galloylglucose, gallic acid, methyl gallate, oxypaeoniflora, paeonolide, apiopaeonoside, albiflorin, paeoniflorin, p-coumaric acid, ferulic acid, 1,2,3,6-tetragalloylglucose, ellagic acid, galloylpaeoniflorin, luteoloside, 1,2,3,4,6-O-penta-galloylglucose, diosmin, neodiosmin, resveratrol, mudanpioside C, benzoyloxypaeoniflorin, benzoylpaeoniflorin, and paeonol. These markers align with component structure theory, allowing for the analysis of the structural characteristics of EPRP from different regions. These findings provide a valuable reference for the future quality evaluation of EPRP, enhance the understanding of the components in EPRP from diverse sources, and lay a foundation for the development and greater utilization of EPRP.