Zythiostromic acid

An unidentified Zythiostroma species, isolated from aspen, was also found to be antagonistic to O. crassivaginatum. Zythiostromic acids A (25) and B (26), as well as zythiostromolide (27) isolated from the culture broth of this fungus, although new natural compounds, were inactive against the blue stain fungi (16) (Chart 5). 

Ayer, W.A., and A.Q. Khan Zythiostromic acids, diterpenoids from an antifungal Zythiostroma species associated with aspen. Phytochem. 42, 1647 (1996). 

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