Analysis of Iridoid Glycoside and GABA Content in the Roots of the Rehmannia glutinosa Cultivars

Background: Rehmannia glutinosa is a perennial herb belonging to the family Scrophulariaceae. Its roots have been utilized as a traditional medicine. The aim of this study was to elucidate the basic information of the roots of the R. glutinosa cultivars and their utilization.Methods and Results: The roots of R. glutinosa cultivars were harvested in the end of March. The two iridoid glycosides, aucubin and catalpol, were analyzed by liquid chromatography/mass spectrometry (LC/MS), whereas γ-aminobutyric acid (GABA) was analyzed by gas chromatography/mass spectrometry (GC/MS). The aucubin content was the highest in the Dakang cultivar, whereas no aucubin was detected in the five cultivars. All cultivars had more than 12 ㎎/g catalpol content, and the maximum catalpol content was found in Jihwang 1. The GABA content was the highest in Suwon 1, and it was 40 times more than that in the Yeongang cultivar.Conclusions: The highest aucubin, catapol and GABA contents were detected in the Dakang, Jihwang 1, and Suwon 1, cultivars respectively. This study provides the crucial information regarding the versatile utilization and pedigree selection of R. glutinosa cultivars.