| 초록 |
In oriental traditional medicine Ephedra Herba has long been used for diaphoretic,anti-asthmatic, and diuretic as well as for the treatment of bronchitis and acute nephriticedema. Especially the alkaloids from Ephedra species (i.e., ephedra alkaloids) are used inmodern medicine for asthma, influenza and inflammation. The main active alkaloids areconsist of L-ephedrine, D-pseudoephedrine, D-norpseudo-ephedrine, L-norephedrine,methylephedrines, L-methylephedrine and D-methyl pseudoephedrine. Thus the quality of thecrude ephedrine-based drug is frequently evaluated in terms of its alkaloid content. To date, the selective isolation of such a great variety of ephedrine derivatives fromEphedra Herba has been solely based on the conventional liquid solvent extraction. However,when one adopts such a conventional technique for the separation of such alkaloids, the useof multistage extraction steps is usually necessary. Thus toward searching for an alternativeextraction process, the CO2-based supercritical fluid extraction (SFE) method was tested forthe selective extraction of the target ephedrine derivatives (i.e., ephedrine, pseudoephedrine,and methylephedrine) from Ephedra sinica Stapf. In fact, upon the present authors’ preliminary experiment, polar substances such asephedrines were not soluble in pure supercritical CO2. Thus, in order to improve thoselimitation of pure CO2 as a supercritical solvent, illustratively the effect of addition of leastamount of polarity modifiers to CO2 was experimentally investigated.
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