Combining MS and NMR methods for identification and authentication of botanicals

Nuclear magnetic resonance (NMR) and mass spectrometry (MS) are powerful and complementary tools for the characterization of botanical materials. Each has their strengths and weaknesses. In this study, authentic samples of Actaea racemosa (black cohosh) and 4 other Actaea species (A. dahurica, A. podocarpa, A. pachypoda, and A. rubra) were obtained from the Bent Creek Germplasm Repository, American Herbal Pharmacopoeia, and Strategic Sourcing, Inc. Samples were sent to AuthenTechnologies for additional identification/authentication using DNA barcoding. The samples were analyzed by NMR and MS with no prior chromatographic separation. The resulting complex spectra were analyzed by principal component analysis (PCA) and soft independent analysis of class analogy (SIMCA). Both analytical methods gave similar results, showing that A. racemosa could be differentiated from the 4 other Actaea species. Both identified the same samples as mislabeled and both provided a sensitivity (authentic samples identified as authentic) of 87% and a specificity (non-authentic samples identified as non-authentic) of 98%. The 87% sensitivity reflected the variation in A. racemosa materials collected from multiple sites by 3 different organizations. Differences may be due to geographic location, DNA modification at isolated sites, or endophytic fungi.