Bioactive -Sativene Sesquiterpenoids from an Endophytic Fungus, .

A series of -sativene sesquiterpenoids (-) including two new natural products ( and ), four new analogues (-), and six known analogues, helminthosporic acid (), drechslerine A (), drechslerine B (), helminthosporol (), helminthosporal acid (), and isosativenediol (), were purified from the endophytic fungus isolated from a desert plant, . The stereochemistry of helminthosporic acid () was established for the first time by X-ray diffraction, and the structures including relative and absolute configurations of these new compounds were determined by NMR and CD spectra together with biosynthetic considerations. Compounds - are the first -sativene sesquiterpenoids possessing a glucose group on C-15, C-15, and C-14, respectively. Compounds , , , and displayed strong phytotoxic effects on corn leaves by producing visible lesions, and helminthosporic acid () was shown to promote division of leaves and roots of with a dose-dependent relationship.