HPLC/UV analysis of polyacetylenes, phenylpropanoid and pyrrolidine alkaloids in medicinally used Codonopsis species.

Introduction: Codonopsis Radix is commonly used as a tonic in traditional Chinese medicine. However, there is no suitable method to assess the quality of Codonopsis Radix based on multiple components having potential bioactivities.

Objective: To establish a HPLC/UV method for simultaneous quantitation of polyacetylenes (lobetyol, lobetyolin, lobetyolinin, cordifolioidyne B), phenylpropanoid (tangshenoside I) and pyrrolidine alkaloids (codonopyrrolidiums A, B) in Codonopsis Radix.

Methods: Large-scale methanol extraction of Codonopsis Radix, followed by chromatographic separation, provided the seven analytes for quantitation standards. Ultrasound-assisted methanol extracts of samples were analysed using reversed phase, gradient elution HPLC monitored at 215 nm.

Results: The method developed allowed efficient separation of the seven compounds and the detection and quantitation limits of the seven analytes were 0.10-0.32 µg/mL and 0.35-1.07 µg/mL, respectively. All calibration curves showed good linearities (r>0.9993) within the test ranges. Intraday and interday precisions were good with RSD<2.84%. The recoveries of all analytes ranged from 95.8 to 104.7%.

Conclusion: HPLC/UV is an efficient and accurate method of analysis for simultaneous quantitation of seven components in Codonopsis Radix.