Chiral recognition of terpenoids in some pharmaceuticals derived from natural sources.

Capillary gas chromatography was applied to explore the enantiomeric composition of some terpenoids in pharmaceuticals of natural origin. The drugs under investigation were produced in Germany (Rowachol, Rowatinex), Poland (Terpichol, Terpinex, Rub arom, Herbolen and Oleum Camphoratum), Slovenia (Uroterp, Mentoklar) and United Kingdom (Olbas oil, Vicks Vapo Rub). The model compounds tested were: menthone, isomenthone, menthol, fenchone, borneol and camphor. It has been found that depending on the manufacturer, pharmaceuticals possessing similar chemical composition may differ considerably in enantiomer composition. Exceptionally large discrepancies have been found for the content of borneol and fenchone enantiomers in pharmaceuticals applied in liver and kidney diseases. It seems that the changes in enantiomeric composition are the main reason of the lack of general acceptance of natural medicines by clinicians. The study of enantiomeric composition may sometimes lead to information concerning the origin of preparation, i.e. natural or synthetic.