Introduction: Further studies of active coumarin components in Radix Angelicae Dahuricae (AE) are absolutely essential to provide data on pharmacology, toxicology and quality for innovative drug candidates. Thus, the preparation of active component standards and the administration of coumarin monomers should be carried out. The isolation of the low-level active components from complex Traditional Chinese Medicine (TCM) samples necessitates the development of rapid, simple and economical modern extraction, separation, identification and purification methods.
Objective: To develop an efficient strategy for the rapid extraction, separation, identification and purification of coumarins from AE.
Methodology: First, active coumarins in AE were extracted with microwave-assisted extraction (MAE) after the extraction conditions were optimised. Second, gradient extraction methods with MAE were used to partially purify AE. Third, a high-performance liquid chromatography-diode array detection-electrospray ionisation tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) method was applied for the preliminary on-line identification and screening of the main coumarins in AE extract. Finally, a two-dimensional preparative high-performance liquid chromatography-diode array detection (2D-prep-HPLC-DAD) system was developed for further preparative separation of those target components.
Results: Altogether 10 coumarins have been identified and five of them including xanthotoxol, osthenol, oxypeucedanin hydrate, byakangelicin and imperatorin were deemed as target components for the preparative isolation. All of the five isolated coumarins were at high purities of over 99% and the production rate was much higher than the traditional methods.
Conclusion: The present paper demonstrates that these consecutive approaches are very useful for to isolate chemical constituents from TCM.