Laccase initiated C-C couplings: Various techniques for reaction monitoring
Laccase initiated C-C couplings: Various techniques for reaction monitoring
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DOI：
10.1016/j.procbio.2015.05.011
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发表时间：
2015-10-01
影响因子：
4.4
通讯作者：
Kragl, Udo
中科院分区：
文献类型：
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作者：
Engelmann, Claudia;Illner, Sabine;Kragl, Udo
在本研究中，研究了来自嗜热毁丝霉 (Novozym (R) 51003) 的真菌漆酶的酚类化合物的氧化 C-C 偶联作用。这种酶只需要分子氧作为氧化剂，这对于氧化偶联反应来说是一个巨大的优势。然而，由于漆酶的自由基反应机制，这种偶联通常被认为是高度非选择性的。基于不同的分析技术，我们对漆酶引发的偶联反应有了详细的了解。通过在漆酶引发的氧化过程中测量氧气来实现潜在底物的预选。此外，由于可以检测溶解的以及固体化合物，原位 FT-IR 光谱法促进了深入分析。该技术可以根据不同的条件检测各种漆酶底物的偶联等级。结果，2,6-二取代酚的氧化二聚可以被鉴定为具有高度选择性，并且可以放大到数克规模。从而2,6-二异丙基苯酚的氧化产物可以很容易地还原为相应的联苯酚，即抗菌剂二丙泊酚。所提出的技术开辟了新的生物催化方法，将醌型单元作为许多天然化合物和药物的关键元素。 (C) 2015 Elsevier Ltd. 保留所有权利。
In this study the fungal laccase from Myceliophthora thermophila (Novozym (R) 51003) was investigated for oxidative C-C couplings of phenolic compounds. This enzyme requires only molecular oxygen as oxidant, which represents a great advantage for oxidative coupling reactions. However, such couplings are typically considered as highly unselective, due to the radical reaction mechanism of laccases. Based on different analytical techniques we gained detailed insights into laccase initiated coupling reactions. A preselection of potential substrates was realized via oxygen measurement during laccase initiated oxidations. Furthermore in situ FT-IR spectroscopy facilitated analyses in-depth, due to feasibility to detect dissolved as well as solid compounds. This technique allowed the detection of the grade of couplings of various laccase substrates, depending on different conditions. As a result oxidative dimerizations of 2,6-disubstituted phenols could be identified as highly selective and were scaled-up to multigram scale. Thereby the oxidation product of 2,6-diisopropyl phenol can be easily reduced to the corresponding biphenol, the antibacterial agent dipropofol. The presented techniques open up new biocatalytical approaches receiving quinoid units as key elements of many natural compounds and pharmaceuticals. (C) 2015 Elsevier Ltd. All rights reserved.