Abstract
The Chinese Umbelliferae plant Ligusticum wallichii was found to contain all the new components previously found in Cnidium officinale, which is closely related with L. wallichii and is used as the source plant of the crude drug “senkyu” in Japan. Three ligustilide derivatives, senkyunolide K (2), senkyunolide L (3), and senkyunolide M (4) were isolated simultaneously and their structures were elucidated as 4β-hydroxylsenkyunolide A (2), 6-hydroxy-7-chloro-6, 7-dihydroligustilide (3) and 6-butyryl-7-hydroxy-6, 7-dihydroligustilide (4) on the basis of the spectral properties. Treatment of ligustilide 6, 7-epoxide with hydrochloric acid readily gave 3 and thus 3 was considered to have been formed during the extraction of the plant.
