Chromatographic Method Comparisons for the Determination of Magnoflorine and Triterpene Saponins from Roots of Blue Cohosh (Caulophyllum thalictroides)

The roots of Cauphyllum thalictroides is traditionally used for the treatment of menstrual difficulties and as an aid in childbirth. C. thalictroides is known to contain saponins which are considered to be responsible for the uterine stimulant effects together with teratogenic alkaloids [1]. A comparison study between HPLC-UV-ELSD, UPLC-UV-ELSD and HPTLC methods was presented for the determination of major alkaloid and triterpene saponins from roots of Caulophyllum thalictroides (blue cohosh) and dietary supplements claiming to contain blue cohosh. The procedure involves the common extraction of the alkaloid and saponins from the plant and dietary samples. By liquid chromatography method with PDA and ELSD, C18 column, mobile phase consisted of solvent A (10 mM ammonium acetate) and solvent B (acetonitrile). Owing to their low UV absorption, the triterpene saponins were detected by evaporative light scattering. Within 35 minutes for HPLC-UV-ELSD method and within 8.0 minutes for UPLC-UV-ELSD method, eight triterpene saponins [cauloside H (2), leoticin D (3), cauloside G (4), cauloside D (5), cauloside B (6), cauloside (7), cauloside (8) and saponin PE (9)] and magnoflorine (1) could be separated, with detection limits of 1–5 µg/mL for saponins and 0.05 µg/mL for magnoflorine by UPLC method, respectively. The methods were successfully used to analyze different dietary products. For the products containing blue cohosh, there was a significant variability in the amounts of the triterpene saponins. The compounds in plant materials and commercial products of blue cohosh were further confirmed by LC-MSD-TOF.

HPLC (A, B) and UPLC (C, D) chromatograms of a mixture of standard (A, C), and roots of blue cohosh (B, D).

Comparison of blue cohosh with dietary products by HPTLC method. Tracks: 1–3, 7, 8; dietary supplements, 5, standard mix-8; 4 & 6, roots of blue cohosh under visible light (Saponins) (A) and at 366 nm (Magnoflorine) (B).

Acknowledgements: This research is funded in part by “Science Based Authentication of Dietary Supplements” Funded by the Food and Drug Administration grant number 2 U01 FD 002071-07. The authors would like to thank Annette Ford, University of Mississippi for extraction of samples. References: [1] Ganzera M, et al. (2003) Phytochem Anal, 14: 1–7.