Triterpenoids and Iridoid Glycosides from Gentiana dahurica

One new and six known pentacyclic triterpenoids, 1 and 4 – 9 , resp., along with two new and three known iridoid glycosides, 2 and 3 , and 10 – 12 , resp., were isolated from the roots of Gentiana dahurica (‘ Qin‐Jiao ’). The new structures were elucidated by means of spectroscopic and chemical methods as 1 β ,2 α ,3 α ,24‐tetrahydroxyursa‐12,20(30)‐dien‐28‐oic acid ( 1 ), 6′‐ O ‐acetylgentiopicroside ( 2 ), and 3′‐acetylgentiopicroside ( 3 ). Isolated compounds were tested for their cytotoxicity against the MCF‐7 human breast cancer cell line using the MTT assay. Among them, triterpenoids 2 α ,3 β ,24‐trihydroxyurs‐12‐en‐28‐oic acid ( 6 ) and 3 β ,24‐dihydroxyurs‐12‐en‐28‐oic acid ( 9 ) were found to have moderate cytotoxic effects with IC 50 values of 20.9 and 21.7 μg/ml, respectively. Additionally, the chemotaxonomic significance of the identified secondary metabolites is briefly discussed.