New triterpenoids from the tubers of Corydalis ternata: structural elucidation and bioactivity evaluation.

Two new triterpene glycosides, coryternic acid 3-O-β-D-glucuronopyranoside (1) and coryternic acid 3-O-β-D-glucuronopyranoside-6'-O-methyl ester (2), were isolated from a MeOH extract of the tubers of Corydalis ternata. Acidic hydrolysis of 1 and 2 yielded a new triterpene as their aglycone, coryternic acid (3). The structures of these new compounds were determined through spectral analysis, including extensive 2D-NMR data. In this study we reported that triterpenoids were first isolated from the genus Corydalis. Compound 2 exhibited significant cytotoxicity against the A549, SK-OV-3, SK-MEL-2, and HCT-15 cell lines (IC50 = 15.16, 17.07, 13.32, and 11.95 µM, respectively) and significantly reduced NO production in lipopolysaccharide (LPS)-activated microglia/BV-2 cells with an IC50 value of 16.2 µM without cell toxicity.