Sativene Sesquiterpenoids from the Plant Endophytic Fungus Bipolaris victoriae S27 and Their Potential as Plant-Growth Regulators.

Thirteen new sativene sesquiterpenoids ( 1 and 3 - 14 ), one new natural product ( 2 ), and 16 known compounds ( 15 - 30 ) were isolated from the endophytic fungus Bipolaris victoriae S27. Their structures were elucidated by extensive spectroscopic analysis, NMR and ECD calculations, and X-ray crystal diffractions. Compound 1 represented the first example of sativene sesquiterpenoids with a 6/5/3/5-caged tetracyclic ring system. All obtained compounds were evaluated for their plant-growth regulatory activity. The results showed that 1 , 3 , 4 , 6 , 8 , 11 , 12 , 17 , 19 , 26 , and 27 could suppress the growth of Arabidopsis thaliana , while 2 , 5 , 13 , 15 , 18 , and 25 showed promoting effects. Among them, compound 3 showed the most potent plant-growth inhibitory activity, which is obviously superior to that of the marked herbicide glyphosate.