Iridoids and other glucosides from Penstemon acuminatus

Abstract

The new iridoid glucoside ester 10-( E)-feruloylaucubin (acuminatuside) along with the known iridoid glucosides eurostoside, 10-( Z)- p-coumaroylaucubin, lytanthosalin, 8-epiloganin, mussaenoside, gardoside methyl ester and the glucosides picein and salidroside have been isolated from the stems of Penstemon acuminatus. The structures have been elucidated primarily on the basis of NMR spectroscopy. The assignments of the NMR signals were performed by means of 1H 1H COSY-45° and 1H 13C COSY experiments.