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7078680 
Journal Article 
Secondary metabolites by chemical screening .29. Agistatines, novel pyranacetals from the fungus FH-A 6239 
Gohrt, A; Grabley, S; Thiericke, R; Zeeck, A; , 
1996 
VCH PUBLISHERS INC 
DEERFIELD BEACH 
627-633 
WOS:A1996UR24700023 
Novel pyranacetals, named agistatines A, B, D, and E (1 to 4), were discovered by a chemical screening in the culture broth of the fungus FH-A 6239. The structures were established by detailed spectroscopic investigations and confirmed by X-ray analysis of agistatine B (2), 4-O-(2-bromobenzoyl)dihydroagistatine A (6), 4-O-(2-bromobenzoyl)agistatine B (7), and agistatine E (4) leading to the stereochemical information. The described secondary metabolites exhibit unusual bicyclic (1 and 3) and tricyclic (2 and 4) structures with a characteristic ketal moiety at C-2 (except 3). The instability of the main fermentation product agistatine E (4) is caused by an additional hemiketal located at the adjacent C-8a.