Sesquiterpenoids from Hedychium yunnanense and Porana discifera, and the structural revision of two sesquiterpenoids from Laggera pterodonta.

A new eudesmane-type sesquiterpenoid, hedytriol (1), was isolated from Hedychium yunnanense (Zingiberaceae). By means of chemical and spectroscopic methods, the structure of 1 was determined as ( - )-7aH-eudesmane-1beta, 4alpha, 11-triol. A new ent-eudesmane sesquiterpenoid, disciferitriol (2), was isolated from Porana discifera (Convolvulaceae), which was exactly the enantiomer of hedytriol (1). The structures of pterodondiol (3a) and pterodontriol B (3), previously isolated from Laggera pterodonta, were revised on the basis of X-ray diffraction, as well as chemical transformations.