Phytochemical fingerprinting to thwart black cohosh adulteration: a 15 Actaea species analysis

Introduction – The popular use of black cohosh products (Actaea racemosa L., syn. Cimicifuga racemosa L.) is growing as the demand for alternatives to estrogen therapy has increased. Critical to safe use is the assurance of unadulterated, high‐quality products. Questions have been raised about the safety of black cohosh due to cases of liver toxicity in patients who reported taking it; subsequent evaluation found some products to be adulterated with other related herbal species. Correct plant species identification is a key first step for good manufacturing practices of safe black cohosh products. Objectives – To develop analytical methods which distinguish black cohosh from other species (American and Asian) of Actaea increasingly found as adulterants in commercially available black cohosh products. Material and methods – Fifteen species of Actaea were collected from North America and Asia, and the phytochemical fingerprints of these samples were established using HPLC‐PDA and LC‐MS techniques. Results – The HPLC and LC‐MS fingerprints for polyphenols and triterpene glycosides revealed distinct patterns that make black cohosh clearly distinguishable from most other species of Actaea. Two marker compounds, cimifugin and cimiracemoside F, were found to be important to distinguish black cohosh from most Asian species of Actaea. Formononetin was not found from either Asian or American species of Actaea. Conclusions – Phytochemical fingerprinting is a practical, reliable method for authenticating black cohosh and distinguishing it from other species of Actaea increasingly found as adulterants in commercially available black cohosh products. This should facilitate the continued development of high‐quality, unadulterated black cohosh products. Copyright © 2011 John Wiley & Sons, Ltd.