title: Quantitative analysis of ephedrine analogues from ephedra species using 1H-NMR.
abstract: Four ephedrine analogues such as ephedrine, pseudoephedrine, methylephedrine, and methylpseudoephedrine were determined by (1)H-NMR from Ephedra species. In the region of delta 5.0-4.0, the signals of H-1 attached to the same carbon with a hydroxyl, were well separated from each other in CDCl(3). The amount of each alkaloid was calculated by the relative ratio of the intensity of H-1 signal to the known amount of internal standard, 200 microg of anthracene. This method allows rapid determination of the quantity of four ephedrine alkaloids from Ephedra species. The amount of these alkaloids was in the range of 1.0-2.0% of dry weight depending on the plant materials.
authors.affiliation: Division of Pharmacognosy, Institute of Biology, Leiden University, The Netherlands.
authors.forename: Hye Kyong
authors.initials: HK
authors.lastname: Kim
authors.forename: Young Hae
authors.initials: YH
authors.lastname: Choi
authors.forename: Wen-Te
authors.initials: WT
authors.lastname: Chang
authors.forename: Robert
authors.initials: R
authors.lastname: Verpoorte
mesh_terms: D029789:Ephedra; D004809:Ephedrine / Q000031:analogs & derivatives* / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010936:Plant Extracts / Q000032:analysis; D018514:Plant Structures; D011522:Protons
chemical_list: D010936:Plant Extracts; D011522:Protons; D004809:Ephedrine