Conformational studies of natural products. Part 4. Conformation and absolute configuration of cascarosides A, B, C, D

Abstract

¹ H and ¹³C NMR spectra for the four carthartic constituents of Cascara bark, namely, the cascarosides A–D are recorded. The conformation and absolute configuration of each component of the two diastereoisomeric pairs have been determined on the basis of anisotropic effects and specific NOE (nuclear Overhauser effects) in their ¹H NMR spectra. CD spectra for these anthrone C,O-diglucosides are reported.