Ephedra (Ma Huang) is a genus of plant, most commonly derived from the dried herbaceous stems of the Chinese species, Ephedra sinica (Figure 1a and 1b). The natural plant source produces six Ephedra alkaloids, chemicals which are considered to be the active constituents of the plant; ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine and methylpsuedoephedrine (Figure 2) (Veitch et al., 2013). The presence and concentrations of these alkaloids depends primarily on the plant species, origin, growing conditions, and the raw plant material processing, with most species largely containing ephedrine and pseudoephedrine (Haller et al., 2004). Metabolomic studies have shown that anatomical parts of Ephedra sinica have different therapeutic pharmacological effects and for this reason, have been used for different purposes in medicine. This was demonstrated by Lv et al (2015), who used GC-MS to compare the concentrations of Ephedra sinica in the stems (Ma Huang) and in the roots (Mahuanggen) of different plant samples. It was concluded that the pharmacologically important ephedrine alkaloids were present in higher quantities in the stems. This is why Ephedra herb, sold as dry stems of Ephedra sinica, has been used as a commercial source of ephedrine alkaloids worldwide, in particular Europe and America (Lee 2011).
Ephedrine is a β-phenylethylamine widely used as a sympathomimetic in herbal preparations. The structure of ephedrine possesses two