Ephedrine and Pseudoephedrine (C6–C1 Part Derived from l-Phenylalanine and Nitrogen Derived by Transamination)

(−)-Ephedrine, m.p. 33–42 °C (depending on the water content) and its diastereomer (+)-pseudoephedrine (also written as (+)-ψ-ephedrine) occur in various Ephedra species [1] (Fam. Ephedraceae). (−)-Ephedrine was first isolated from the Chinese drug “Ma Huang” in 1885 and was purified in 1887 by Nagai who also obtained pseudoephedrine from the same source. The drug Ma Huang is reported to be Ephedra sinica as well as a mixture of E. equisetina, E. sinica, and E. distachya. Ephedra belongs to the order Ephedrales, of which it is a single genus [2]. In some literature, the genus Ephedra has been included in the family Gnetaceae [3]. The E. sinica plant extracts containing (−)-ephedrine have been used for nearly 5,000 years in Chinese folk medicine. The genus Ephedra is not confined to China and Japan but has a much wider geographical distribution [1, 3, 4]. Ephedrine and ψ-ephedrine are also obtained from other sources [1].