Gas chromatographic and mass spectrometric studies of the constituents of the rhizome of calamus

The composition of the volatile oil of European calamuse (Acorus calamus L.) was investigated by liquid—solid chromatography and gas chromatography—mass spectrometry (GC—MS). A total of 184 volatile components were detected, including 67 hydrocarbons, 35 carbonyl compounds, 56 alcohols, 8 phenol, 2 furans and 4 oxido-compounds. The essential oil of Indian calamus was also analyzed by GC—MS and 93 volatile components were detected, β-asarone being the major component. A probable oxidation scheme for β-asarone is shown and the importance of minor components for the development of calamus aroma is also discussed. Of the 125 and 79 components identified in the European and Indian oils, respectively 72 and 39 had not been reported previously in calamus oil.