Abstract
From the leaves of Penstemon nitidus Dougl. (smooth blue beardtongue) besides the known iridoid glucosides cornin (syn.
verbenalin), hastatoside and β-dihydrohastatoside the new compound 10-hydroxycornin
has been isolated. The structures of all compounds were established by spectroscopic
means (FD-MS, 1 H-, 13 C-, 2D-NMR, and NOE). This is the first report of cornin and analogous 6-keto iridoids
in scrophulariaceous plants. Up to now iridoid glucosides like these have only been
found in plants belonging to the Cornaceae and its allies and to the Lamiaceae-Verbenaceae
complex.
Key words
Penstemon nitidus
- Scrophulariaceae - iridoid glucosides - cornin - hastatoside - β-dihydrohastatoside
- 10-hydroxycornin - structure elucidation
