Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Proc Natl Acad Sci U S A. 2012 Jun 19;109(25):9727-32. doi: 10.1073/pnas.1206708109. Epub 2012 Jun 4.
Isomerization of sugars is used in a variety of industrially relevant processes and in glycolysis. Here, we show that hydrophobic zeolite beta with framework tin or titanium Lewis acid centers isomerizes sugars, e.g., glucose, via reaction pathways that are analogous to those of metalloenzymes. Specifically, experimental and theoretical investigations reveal that glucose partitions into the zeolite in the pyranose form, ring opens to the acyclic form in the presence of the Lewis acid center, isomerizes into the acyclic form of fructose, and finally ring closes to yield the furanose product. The zeolite catalysts provide processing advantages over metalloenzymes such as an ability to work at higher temperatures and in acidic conditions that allow for the isomerization reaction to be coupled with other important conversions.
糖的异构化在各种工业相关的过程和糖酵解中都有应用。在这里，我们表明，具有骨架锡或钛路易斯酸中心的疏水性沸石β通过类似于金属酶的反应途径异构化糖，例如葡萄糖。具体来说，实验和理论研究表明，葡萄糖以吡喃糖的形式分配到沸石中，在路易斯酸中心的存在下，开环形成无环形式，异构化为果糖的无环形式，最后环合生成呋喃糖产物。与金属酶相比，沸石催化剂具有一些优势，例如能够在高温和酸性条件下工作，这使得异构化反应能够与其他重要的转化反应偶联。
