Fingerprint profile analysis of hirudo polypeptide based on UHPLC–MS and its application

Hirudo is a medicinal and edible homologous animal. Its rich polypeptides have been proven to have strong biological activity and effects on human health or disease. However, the quality control of hirudo can still be improved. Based on the traditional scientific understanding of oral hirudo administration, this study adopted artificial gastric‐juice extraction combined with pepsin enzymolysis to simulate the digestion and absorption of gastrointestinal tract after taking hirudo. Ultrahigh‐performance liquid chromatography–mass spectrometry technology was initially used to screen and characterize 52 enzymolysis components of hirudo. The fingerprint of hirudo enzymolysis polypeptide was then established. The method was confirmed to have high accuracy, repeatability, and stability. Using the established hirudo enzymolysis polypeptide fingerprint, we proved that it can effectively identify different origins of hirudo. The established fingerprint revealed that 19 enzymolysis polypeptides derived from hirudo in the Qizhi capsule, indicating that it can promote and improve the quality control of Qizhi capsule. The present study provided a new technology and idea for the origin identification and quality control of hirudo, and standards for Chinese patent medicines containing hirudo. It can also serve as a reference for the quality control of other animal‐origin drugs or foods.