Constituents of Cnidium officinale MAKINO. Structure of Senkyunolide and Gas Chromatography-Mass Spectrometory of the Related Phthalides

Abstract

From the ether extract of C. officinale (Umbelliferae; Japanese name Senkyu), 6 phthalides were isolated by column and preparative TLC. One of them was a new phthalide and named senkyunolide. The structure of senkyunolide was determined by correlation with the known butylphthalide as (3S)-3-butyl-4,5-dihydrophthalide. Mass spectroscopy was the most satisfactory method for structural analysis of phthalides and showed a definite systematic fragmentation starting from the cleavages at the allylic position.