Ephedra plants, the main components of which are ephedrine alkaloids, are used as traditional medicines in Eastern Asian countries. In this study, we isolated non-ephedrine constituents from various Ephedra plant species cultivated in Japan. HPLC analysis suggested that kynurenic acid and its derivatives accumulated in a wide range of Ephedra plant species. Furthermore, a large amount of (2R,3S)-O-benzoyl isocitrate has been isolated from E. intermedia. This study suggests that Ephedra plants have diverse non-ephedrine constituents.
Keywords: (2R,3S)-O-benzoyl isocitrate; Ephedra plant; kynurenic acid; non-ephedrine constituent.