Detailed Mechanistic Study of the Non-enzymatic Formation of the Discoipyrrole Family of Natural Products.
Detailed Mechanistic Study of the Non-enzymatic Formation of the Discoipyrrole Family of Natural Products.
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DOI：
10.1021/jacs.5b13320
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发表时间：
2016-02-24
影响因子：
15
通讯作者：
MacMillan JB
中科院分区：
文献类型：
--
作者：
Colosimo DA;MacMillan JB
Discoipyrroles A-D（DPA-DPD）是近年来发现的由海洋细菌湖南芽孢杆菌（Bacillus hunanensis）产生的具有体外抗癌活性的天然产物。初步的生物合成研究表明，DPA是在B的液体发酵培养基中形成的。hunanensis通过一个未知的，但不依赖于蛋白质的机制从三个分泌代谢产物。对依赖于非酶促步骤的天然产物的鉴定的增加产生了理解这些不同反应如何发生的显著需求。在这项工作中，我们利用15 N-标记的起始材料和连续的高灵敏度1H-15 N HMBC NMR光谱，以解决稀缺的反应中间体的非酶discoipyrrole反应，因为它们形成在真实的时间。这些信息指导了使用13 C和18 O标记材料的补充实验，以阐明DPA的非酶生物合成的细节，其特征是高度一致的吡咯形成和必要的O2介导的氧化。我们已经说明了一种新的方法，使用同位素增强二维NMR光谱询问反应机制，因为它们发生。此外，这些发现增加了我们对多组分非酶反应如何通过固有反应性细菌代谢物发生的知识。
Discoipyrroles A–D (DPA–DPD) are recently discovered natural products produced by the marine bacterium Bacillus hunanensis that exhibit anticancer properties in vitro. Initial biosynthetic studies demonstrated that DPA is formed in the liquid fermentation medium of B. hunanensis from three secreted metabolites through an unknown but protein-independent mechanism. The increased identification of natural products that depend on non-enzymatic steps creates a significant need to understand how these different reactions can occur. In this work, we utilized 15N-labeled starting materials and continuous high-sensitivity 1H–15N HMBC NMR spectroscopy to resolve scarce reaction intermediates of the non-enzymatic discoipyrrole reaction as they formed in real time. This information guided supplemental experiments using 13C- and 18O-labeled materials to elucidate the details of DPA’s non-enzymatic biosynthesis, which features a highly concerted pyrrole formation and necessary O2-mediated oxidation. We have illustrated a novel way of using isotopically enhanced two-dimensional NMR spectroscopy to interrogate reaction mechanisms as they occur. In addition, these findings add to our growing knowledge of how multicomponent non-enzymatic reactions can occur through inherently reactive bacterial metabolites.