Sesquiterpenoids and Xanthones from the Kiwifruit-Associated Fungus Bipolaris sp. and Their Anti-Pathogenic Microorganism Activity.

Nine previously undescribed sesquiterpenoids, bipolarisorokins A-I ( 1 - 9 ); two new xanthones, bipolarithones A and B ( 10 and 11 ); two novel sativene-xanthone adducts, bipolarithones C and D ( 12 and 13 ); as well as five known compounds ( 14 - 1 8 ) were characterized from the kiwifruit-associated fungus Bipolaris sp. Their structures were elucidated by extensive spectroscopic methods, electronic circular dichroism (ECD), 13 C NMR calculations, DP4+ probability analyses, and single crystal X-ray diffractions. Many compounds exhibited anti-pathogenic microorganism activity against the bacterium Pseudomonas syringae pv. actinidiae and four pathogenic microorganisms.