NMR for the identification and quantification of isoquinoline alkaloids in plant extracts: Application to Goldenseal

NMR spectroscopy is a powerful technique for identifying and quantifying components in complex mixtures such as plant extracts. Multiple compounds can be identified in the same spectrum recorded on a crude extract. Typical 1D ¹H spectra require less than 10 minutes for data acquisition and analysis. Here we apply this technology to goldenseal. Goldenseal (Hydrastis canadensis) is a plant belonging to buttercup family (Ranunculaceae) native to North America with a range from southeastern Canada through the eastern United States. The plant has been used by Native Americans for medicinal purposes. Key compounds in goldenseal, such as the isoquinolone alkaloids berberine 1, canadine 2, and hydrastine 3, are thought to be responsible for its biological activity. Here we demonstrate quantification of these components from unfractionated goldenseal root extract by NMR spectroscopy. The measurement can be automated with the Assure-RMS software from Bruker.

Fig. 1