NMR Confirmation That Tryptophan Dehydrogenation Occurs with Syn Stereochemistry during the Biosynthesis of CDA in Streptomyces coelicolor

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• 作者：Bagher Amir-Heidari ; Jason Micklefield
• 刊名：Journal of Organic Chemistry
• 出版年：2007
• 出版时间：November 9, 2007
• 年：2007
• 卷：72
• 期：23
• 页码：8950 - 8953
• 全文大小：150K
• 年卷期：v.72,no.23(November 9, 2007)
• ISSN：1520-6904

文摘

Doubly labeled (2'S,3'R)-[3'-²H₁,¹³C₁]-tryptophan was fed tothe Trp-His auxotrophic Streptomyces coelicolor strainWH101. Mass spectrometry showed single and doubleincorporation of the labeled Trp into the calcium-dependentlipopeptide antibiotic (CDA4a). From ¹³C NMR spectroscopy, it was apparent that the C3'-signal of the (Z)-2',3'-dehydrotryptophan (position 11 in CDA4) was a 1:1:1 tripletindicating that the deuterium atom in the pro-R position ofthe methylene group is retained during Trp-oxidation. Thisprovides definitive proof that Trp dehydrogenation occursthrough the loss of the 2' and pro-3'S hydrogen atoms withoverall syn stereochemistry.