Dammarane triterpenoids from the roots of Gentiana rigescens

Six new minor dammarane triterpenoids were isolated from the roots of Gentiana rigescens. These include one aglycone, gentirigenic acid (1), and five glycosides, gentirigeosides A-E (2-6). Their structures were elucidated through detailed spectroscopic analyses, including 1D and 2D NMR techniques, and enzymatic hydrolysis. Antifungal testing of these compounds showed that the glycosides gentirigeosides A (2), C (4), and E (6) had antifungal activity against the plant pathogen Glomerella cingulata.