Z-Butylidenephtalide in the Essential Oil from Roots of Levisticum officinale

Abstract

Z-butylidenephtalide was prepared by means of a stereospecific synthesis method. Its configuration was confirmed by 'H-NMR measurements and experiments on photochemical isomerization. The Z-compound was found to be the only butylidenephtalide isomer present in a commercial sample of essential oil from the roots of Levisticum officinale Koch, as well as in freshly distilled oil. UV irradiation induces isomerization from the Z-to the E-isomer with markedly different organoleptic properties. Key Word Index Levisticum officinale - Apiaceae (Umbelliferae) - Essential Oil - Z-Butylidenephtalide.