Identification of sesquiterpene glycosides from Dendrobium nobile and their α-glycosidase and α-amylase inhibitory activities

Dendrobium nobile is a traditional Chinese medicine and functional food in China, with anti-aging, immunity-enhancing, glucose-lowering and lipid-lowering health functions. In recent years, the research value of D. nobile has attracted the attention of more and more experts and scholars. Today, phytochemical investigation of the stems of Dendrobium nobile Lindl., led to the isolation of five sesquiterpene glycosides, including dendromoniliside D (1), dendronobiloside A (2), dendronobiloside C (3), dendronobiloside D (4), dendroside G (5) and their α-amylase and α-glycosidase inhibitory activities were also investigated. Among them, dendromoniliside D (1), dendroside G (5) were first isolated from D. nobile. And dendronobiloside A (2) and dendronobiloside C (3) exhibited better inhibitory activity against α-glycosidases, respectively. In the case of α-amylase inhibition, dendroside G (5) has a relatively good effect. These results suggest that sesquiterpene glycosides of D. nobile have potential hypoglycemic activity and deserve further research and development.