Xuejiao Li1, Ying Wang2, Jiachen Sun3, Xia Li1, Chengcheng Zhao1, Ping Zhao1, Shuli Man4, Wenyuan Gao1,2,4. 1. Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China. 2. Tianjin Key Laboratory of Chemistry and Analysis of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China. 3. College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, 300134, China. 4. Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China.
Abstract
INTRODUCTION: Dioscorea species, which contain abundant steroidal saponins, have been used as folk medicines or raw materials to synthesise steroid drugs. OBJECTIVE: To establish a rapid chemotaxonomic method that will comprehensively resolve confusions about genetic relationships of genus Dioscorea. METHODS: A comprehensive strategy using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) was firstly proposed to evaluate the chemotaxonomy of 12 species (27 taxa) from China by hierarchical cluster analysis (HCA) based on the variations of the identified metabolites. RESULTS: Twenty-eight secondary metabolites (mainly steroidal saponins) were identified. The MSn fragmentation patterns of DA (a new acetylated steroidal saponin at C-7 position) were firstly reported. Moreover, eight major steroidal saponins were further quantified simultaneously by UPLC-QTOF-MS method. According to HCA results, D. bulbifera L. was distinguished with species of sect. Stenophora Uline for pennogenin-type steroidal saponins. Dioscorea zingiberensis exhibited far distance from other members of sect. Stenophora Uline for two unique saponins. Dioscorea banzhuana may be reclassified into sect. Stenophora. Dioscorea nipponica subsp. rosthornii and D. collettii var. hypoglauca might be separated from their original subspecies/varieties as new species, respectively. CONCLUSION: The chemotaxonomic method was successfully applied in the study of genetic relationships of Dioscorea species. This study not only enhanced the understanding of chemical constituents, but also laid basic theoretical foundations for the rational utilisation and chemotaxonomy of genus Dioscorea.
INTRODUCTION:Dioscorea species, which contain abundant steroidal saponins, have been used as folk medicines or raw materials to synthesise steroid drugs. OBJECTIVE: To establish a rapid chemotaxonomic method that will comprehensively resolve confusions about genetic relationships of genus Dioscorea. METHODS: A comprehensive strategy using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) was firstly proposed to evaluate the chemotaxonomy of 12 species (27 taxa) from China by hierarchical cluster analysis (HCA) based on the variations of the identified metabolites. RESULTS: Twenty-eight secondary metabolites (mainly steroidal saponins) were identified. The MSn fragmentation patterns of DA (a new acetylated steroidal saponin at C-7 position) were firstly reported. Moreover, eight major steroidal saponins were further quantified simultaneously by UPLC-QTOF-MS method. According to HCA results, D. bulbifera L. was distinguished with species of sect. Stenophora Uline for pennogenin-type steroidal saponins. Dioscorea zingiberensis exhibited far distance from other members of sect. Stenophora Uline for two unique saponins. Dioscorea banzhuana may be reclassified into sect. Stenophora. Dioscorea nipponica subsp. rosthornii and D. collettii var. hypoglauca might be separated from their original subspecies/varieties as new species, respectively. CONCLUSION: The chemotaxonomic method was successfully applied in the study of genetic relationships of Dioscorea species. This study not only enhanced the understanding of chemical constituents, but also laid basic theoretical foundations for the rational utilisation and chemotaxonomy of genus Dioscorea.