Concentrations of the alkaloids magnoflorine, N‐methylcystine and baptifoline in samples of blue cohosh

Abstract

Preparations of roots of Blue Cohosh (Caulophyllum thalictroides) have been promoted for their estrogen-like benefits and are sold as dietary supplements in the form of powder, tablet and liquid. The safety and efficacy of such preparations have not been systematically evaluated. Recent studies indicate that ingestion of Blue Cohosh can produce birth defects and neonatal heart failure in humans. These effects may be due to some of the alkaloids present in the plant preparations. Two such alkaloids, baptifoline and N-methylcytisine, possess anti-inflammatory and mutagenic properties. We purified magnoflorine, N-methylcytisine and baptifoline from rhizomes of authenticated plant material and used these alkaloids as external standards during the analysis of commercial samples. Rhizomes of authenticated Blue Cohosh were obtained from Botanical Liaisons, Boulder CO. Samples of Blue Cohosh in powder, capsule and liquid forms were obtained from commercial sources. The rhizomes were powdered in a blender, sieved through a #60 sieve and extracted in methanol (5g/25mL). The contents of 10 capsules were mixed and 0.5g extracted in 10mL methanol. Liquid samples were diluted 1:10 with methanol. All samples were analyzed by HPLC using an XTerra Phenyl reversed phase HPLC column with a gradient mobile phase consisting of water and acetonitrile, each with 2 mM ammonium bicarbonate and 0.1% ammonium hydroxide. All three alkaloids were detected in all samples with magnoflorine present in the highest concentrations and baptifoline in the lowest concentrations.