Streptoverticillium fervens

The full structure and absolute configuration of FR 900848 104 has been determined to be (6R,8S,9R,11S,12S,14R,15S,17R) from X-ray crystallographic study [133]. Strategies for its enantioselective total synthesis are based on an iterative cyclopropanation [134], and on the use of chiral auxiliaries [135]. It has also been prepared by fermentation and isolated from cultures of Streptoverticillium fervens to be considered as an agrochemical microbicide [136]. 

The recently discovered partially cyclopropanated polyenamide FR-900848 (45), is a nucleoside isolated from the fermentation broth of Streptoverticillium fervens [88], and shows potent selective activity... 

Ribofuranosyl Analogues. - New nucleoside antibiotics to be reported have included the antifungal compound FR 900403 (15) obtained from the broth of Kernia sp. F-19849, the antifungal antibiotic FR 900848 (16) from Streptoverticillium fervens, containing a novel... 

An impressive example of the use of the Simmons-Smith reagent in the construction of natural products is the highly unusual, potent antifungal agent FR-9(X)848, obtained in 1990 from a fermentation broth of Streptoverticillium fervens and first synthesized in 1996. Its most noteworthy feature is the fatty acid residue, which contains five cyclopropanes, four of which are contiguous and all of which were made by Simmons-Smith cyclopropanations. 

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