Two new trans-fused iridoid glycosides (5 alpha H)-6 alpha-8-epidihydrocornin and (5 alpha H)-6 alpha-8-hydroxy-8-epiloganin, were isolated from Penstemon mucronatus, along with cornin, penstemoside and three hastato-sides. The trans-fused iridoids are only the second and third known among over 900 described cis-fused iridoid glycosides. Two pairs of iridoids, identical except for the stereochemistry at C-8, were found. Structures were determined by spectroscopic methods.
isolation, taxonomy, Scrophulariaceae, iridoid glycosides, Penstemon mucronatus
Publication DOI: 10.1016/S0031-9422(98)00349-5Journal NLM ID: 0151434Publisher: Elsevier
Institutions: Department of Chemistry, Colorado State University, Fort Collins, US
Methods: 13C NMR, 1H NMR, HPLC, extraction, HMQC, HR-FAB-MS, VLC, optica rotation measurement
Found