Withanolide y a withanolide from a hybrid of withania somnifera
Bessalle, R.; Lavie, D.; Frolow, F.
Phytochemistry 26(6): 1797-1800
1987
ISSN/ISBN: 0031-9422
DOI: 10.1016/s0031-9422(00)82291-8
Accession: 006919957
The structure of a withanolide isolated from the hybrid of Withania somnifera chemotype III (Israel) by Indian I (Delhi) has been elucidated as (20R,22R)-5.alpha.,6.alpha.-epoxy-7.alpha.-17.alpha.,20-trihydroxy-1-oxo-witha-2,24-dienolide by X-ray single crystal analysis. This compound is the first example of a 5.alpha.,6.alpha.-epoxy-7.alpha.-hydroxy system among the withanolides, and thus provides an additional step in the biosynthetic pathway. Its reaction with trichloroacetyl isocyanate has been followed by 1H NMR and compared with withanolide T.