抄録
Gas chromatographic examinations were made on the essential oils of Chinese and Japanese Gaobens (Kohon) and related plants, namely, Nothosmyrnium japonicum and Osmorhiza aristata. The essential oil of Chinese Gaoben, whose original plant is Ligusticum sinense, contains mainly 3-butylphthalide, cnidilide, and an un-didentified compound X, and its chemical nature is similar to that of Japanese Chuanxiong (Senkyu, Cnidii Rhizoma). One of Japanese Gaobens now on the market consists mainly of osmorhizole (2, 4-dimethoxy-1-allylbenzene), isoosmorhizole (nothosmyrnole, 2, 4-dimethoxy-1-propenyl-benzene), and anethole, and the chemical constituents are the same as those of the oil of Osmorhiza aristate. The oil of Nothosmyrnium japonicum contains mainly dillapiole, nothoapiole, and an un-identified compound, and the structure of nothoapiole is assumed to be 2, 3, 6-trimethoxy-4, 5-methylendioxy-1-allylbenzene. During synthesis of osmorhizole (Chart 1), the Claisen rearrangement was found to occur at two ortho positions.
