NMR confirmation that tryptophan dehydrogenation occurs with Syn stereochemistry during the biosynthesis of CDA in Streptomyces coelicolor
NMR confirmation that tryptophan dehydrogenation occurs with Syn stereochemistry during the biosynthesis of CDA in Streptomyces coelicolor
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DOI：
10.1021/jo701660v
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发表时间：
2007-11-09
影响因子：
3.6
通讯作者：
Micklefield, Jason
中科院分区：
文献类型：
--
作者：
Amir-Heidari, Bagher;Micklefield, Jason
[图形]将双标记的（2'S，3 'R）-[3'-H-2（1），C-13（1）]-色氨酸饲喂Trp-His营养缺陷型天蓝色链霉菌菌株WH 101。质谱分析表明，单和双掺入标记的色氨酸钙依赖性脂肽抗生素（CDA 4a）。根据C-13 NMR光谱，显然（Z）-2 '，3'脱氢色氨酸（CDA 4中的位置11）的C3 '-信号是1：1：1三联体，表明在Trp-氧化期间保留了亚甲基的pro-R位置上的氘原子。这提供了明确的证据，即Trp脱氢是通过损失2'和pro-3'S氢原子而发生的，具有整体的顺式立体化学。
[GRAPHICS]Doubly labeled (2'S,3'R)-[3'-H-2(1),C-13(1)]-tryptophan was fed to the Trp-His auxotrophic Streptomyces coelicolor strain WH101. Mass spectrometry showed single and double incorporation of the labeled Trp into the calcium-dependent lipopeptide antibiotic (CDA4a). From C-13 NMR spectroscopy, it was apparent that the C3'-signal of the (Z)-2',3'dehydrotryptophan (position 1 1 in CDA4) was a 1: 1: 1 triplet indicating that the deuterium atom in the pro-R position of the methylene group is retained during Trp-oxidation. This provides definitive proof that Trp dehydrogenation occurs through the loss of the 2' and pro-3'S hydrogen atoms with overall syn stereochemistry.