Echinothiophene, a Novel Benzothiophene Glycoside from the Roots of <i>Echinops grijissii</i>

Abstract

The structure of echinothiophene, the β-d-glucoside of a benzo[b]thiophene lactone bearing a novel skeleton, has been deduced from extensive NMR and MS studies. The compound undergoes facile epimerization at the C-6 center, perhaps through the enol 2. Molecular mechanics and dynamics calculations indicated that the structure 1 (C-6, R) is more stable than 3 (C-6, S).