High resolution nmr and x-ray crystallography data of caudicifolin from Euphorbia acaulis

Abstract

A diterpene lactone was isolated from the cold petrol (60−80°) extract of rhizomes of Euphorbia acaulis, a plant material used by a tribe of central India for curing various inflammatory disorder. The diterpene, which was observed to be identical to caudicifolin on the basis of its physical constants, was subjected to high resolution NMR spectroscopy and X-ray crystallography examination. This paper reports the salient features of the 2D 1H NMR, 13C NMR and X-ray crystallography data of the compound. 13C NMR assignments were made by the use of proton noise decoupling, SFORD, APT and automatic spectral editing techniques. 1H NMR assignments were made with the aid of a COSY experiment for long range couplings and NOE correlated 2D-experiments. The 1H and 13C NMR spectral assignments have been further corroborated by H/C correlation experimental results.