Stereochemical elucidation of streptorubin B
Haynes, Stuart W., Sydor, Paulina K., Corre, Christophe, Song, Lijiang and Challis, Gregory L.. (2011) Stereochemical elucidation of streptorubin B. Journal of the American Chemical Society, Vol.133 (No.6). pp. 1793-1798. ISSN 0002-7863Full text not available from this repository.
Official URL: http://dx.doi.org/10.1021/ja109164t
Streptorubin B is a structurally remarkable mem-ber of the prodiginine group of antibiotics produced by several actinobacteria, including the model organism Streptomyces coelicolor A3(2). Transannular strain within the pyrrolophane structure of this molecule causes restricted rotation that gives rise to the possibility of (diastereomeric) atropisomers. Neither the relative nor the absolute stereochemistry of streptorubin B is known. NOESY NMR experiments were used to define the relative stereochemistry of the major atropisomer of streptorubin B·HCl in solution as anti. We exploited this finding together with our knowledge of streptorubin B biosynthesis in S. coelicolor to determine the absolute stereochemistry of the anti atropisomer. 2-Undecylpyrrole stereoselectively labeled with deuterium at C-4′ was synthesized and fed to a mutant of S. coelicolor, which was unable to produce streptorubin B because it was blocked in 2-undecylpyrrole biosynthesis, and in which the genes responsible for the last two steps of streptorubin B biosynthesis were overexpressed. 1H and 2H NMR analysis of the stereoselectively deuterium-labeled streptorubin B·HCl produced by this mutasynthesis strategy allowed us to assign the absolute stereochemistry of the major (anti) atropisomer as 7′S. HPLC analyses of streptorubin B isolated from S. coelicolor on a homochiral stationary phase and comparisons with streptorubin B derived from an enantioselective synthesis showed that the natural product consists of an approximately 88:7:5 mixture of the (7′S, anti), (7′S, syn), and (7′R, anti) stereoisomers.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry
Q Science > QR Microbiology
|Divisions:||Faculty of Science > Chemistry|
|Library of Congress Subject Headings (LCSH):||Stereochemistry, Streptomyces, Biosynthesis|
|Journal or Publication Title:||Journal of the American Chemical Society|
|Publisher:||American Chemical Society|
|Official Date:||16 February 2011|
|Page Range:||pp. 1793-1798|
|Access rights to Published version:||Restricted or Subscription Access|
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