The essential oil constituents in Zedoariae Rhizoma (Gajutsu in Japanese) originated in China, Taiwan, and Yakushima (Japan) were analyzed by means of gas liquid chromatography-mass spectrometry (GC-MS) by using hitherto elucidated nine sesquiterpenoids (1-9) as standard substances. Each essential oil gave a characteristic reconstructed ion current chromatogram as shown by the qualitative analysis and the essential oil composition of Rhizoma from Yakushima was shown to be a sum of the essential oil compositions of Rhizoma from China and Taiwan. The major sesquiterpenoid of each essential oil was shown by the quantitative analysis as furanogermenone (8) in Rhizoma from China, curcumenol (6) in Rhizoma from Taiwan, or dehydrocurdione (4) in Rhizoma from Yakushima (Japan).
