A rapid and feasible1 H-NMR quantification method of ephedrine alkaloids in ephedra herbal preparations

Hsin Yi Hung, Shih Min Lin, Chia Ying Li, Sio Hong Lam, Yu Yi Chan, Meei Jen Liou, Po Chuen Shieh, Fu An Chen, Ping Chung Kuo, Tian Shung Wu

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


A highly specific and sensitive proton nuclear magnetic resonance (1 H-NMR) method has been developed for the quantification of ephedrine alkaloid derivatives in Ephedra herbal commercial prescriptions. At the region of δ 4.0 to 5.0 ppm in the1 H NMR spectrum, the characteristic signals are separated well from each other, and six analogues in total, methylephedrine (ME), ephedrine (EP), norephedrine (NE), norpseudoephedrine (NP), pseudoephedrine (PE), and methylpseudoephedrine (MP) could be identified. The quantities of these compounds are calculated by the relative ratio of the integral values of the target peak for each compound to the known concentrations of the internal standard anthracene. The present method allows for a rapid and simple quantification of ephedrine alkaloid derivatives in Ephedra-related commercial prescriptions without any preliminary purification steps and standard compounds, and accordingly it can be a powerful tool to verify different Ephedra species. In comparison to conventional chromatographic methods, the advantages of this method include the fact that no standard compounds are required, the quantification can be directly performed on the crude extracts, a better selectivity for various ephedrine alkaloid derivatives, and the fact that a very significant time-gain may be achieved.

Original languageEnglish
Article number1599
Issue number6
Publication statusPublished - 2021 Mar 2

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Chemistry (miscellaneous)
  • Molecular Medicine
  • Pharmaceutical Science
  • Drug Discovery
  • Physical and Theoretical Chemistry
  • Organic Chemistry


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