Comprehensive Quality Evaluation of the Root Bark of Morus alba L. Based on High-Performance Liquid Chromatography Fingerprinting and Chemometric Analyses

The quality of the root bark of Morus alba L. (SBP) herbs currently circulating in the market is variable. In order to ensure clinical effectiveness, a high-performance liquid chromatography (HPLC) fingerprinting method combined with chemical pattern recognition should be established to control the quality of SBP herbs. The differences of 23 batches of SBP were analyzed by exploratory cluster analysis based on shared fingerprint peak data, and the results indicated that the processing method to remove the cork layer from SBP materials is an important influencing factor on SBP quality. Principal component analysis indicated that SBP samples with the cork layer removed can be clearly distinguished from samples without cork layer removal. The potential chemical markers (kuwanon G, morusin and oxyresveratrol) were screened by partial least squares discriminant analysis. Finally, the contents of the main components were determined, indicating that the processing method of SBP materials can affect content of bioactive ingredients and that cork layer removal leads to a more uniform chemometric profile. The HPLC-based chemometrics approach described here will support the development of quality standards in SBP products.