L-Norpseudoephedrine

L-Norpseudoephedrine, or (−)-norpseudoephedrine, less commonly known as (–)-cathine or L-cathine, is a psychostimulant drug of the amphetamine family. It is the levorotary isomer of Norpseudoephedrine and is one of the 4 optical isomers of phenylpropanolamine ((−)-norpseudoephedrine, (+)-norpseudoephedrine, (−)-norephedrine, & (+)-norephedrine).

L-Norpseudoephedrine is an alkaloid of Ephedra sinica, Ephedra equisetina, and Catha edulis (khat). In khat, L-norpseudoephedrine is a secondary alkaloid present alongside cathinone. It is likely responsible for some of the milder stimulant effects of the plant, while cathinone produces the stronger psychoactive effects. In the Ephedra genus, L-norpseudoephedrine is a trace alkaloid compared to the more abundant alkaloids ephedrine and pseudoephedrine. Unlike in khat, L-Norpseudoephedrine does not contribute significantly to the pharmacological actions of Ephedra, as the amount contained in stems/leaves is negligible.