Quantification and identification of bioactive metabolites from Kalopanacis Cortex by HPLC with evaporative light scattering detection and ESI quadrupole TOF MS

A method based on HPLC coupled with an evaporative light scattering detection and ESI quadrupole TOF MS was established for the quantification and identification of phenolics and triterpene saponins in Kalopanacis Cortex using a gradient elution of acetonitrile with 0.1% formic acid and water with 0.1% formic acid on an RP C₁₈ column (4.6 × 250 mm, 5 μm). Diverse validation parameters, such as the linearity, LOD and LOQ, accuracy, precision, repeatability, and stability, were successfully obtained. Additionally, the efficiencies of different extraction methods were compared. The developed method was applied for the quantitative analysis of twelve representative metabolites in 61 Kalopanacis Cortex samples. The quantitation results showed that coniferin, kalopanaxsaponin C, septemlosides II, III, C, and D exhibited distinct regional patterns in Kalopanacis Cortex samples. These six compounds including one new triterpene saponin show potential as marker compounds for evaluating the quality of Kalopanacis Cortex and the geographical variation in its chemical composition.