13051-49-5Relevant articles and documents
Competence of Thiamin Diphosphate-Dependent Enzymes with 2′-Methoxythiamin Diphosphate Derived from Bacimethrin, a Naturally Occurring Thiamin Anti-vitamin
Nemeria, Natalia S.,Shome, Brateen,Decolli, Alicia A.,Heflin, Kathryn,Begley, Tadhg P.,Meyers, Caren Freel,Jordan, Frank
, p. 1135 - 1148 (2016)
Bacimethrin (4-amino-5-hydroxymethyl-2-methoxypyrimidine), a natural product isolated from some bacteria, has been implicated as an inhibitor of bacterial and yeast growth, as well as in inhibition of thiamin biosynthesis. Given that thiamin biosynthetic enzymes could convert bacimethrin to 2′-methoxythiamin diphosphate (MeOThDP), it is important to evaluate the effect of this coenzyme analogue on thiamin diphosphate (ThDP)-dependent enzymes. The potential functions of MeOThDP were explored on five ThDP-dependent enzymes: the human and Escherichia coli pyruvate dehydrogenase complexes (PDHc-h and PDHc-ec, respectively), the E. coli 1-deoxy-d-xylulose 5-phosphate synthase (DXPS), and the human and E. coli 2-oxoglutarate dehydrogenase complexes (OGDHc-h and OGDHc-ec, respectively). Using several mechanistic tools (fluorescence, circular dichroism, kinetics, and mass spectrometry), it was demonstrated that MeOThDP binds in the active centers of ThDP-dependent enzymes, however, with a binding mode different from that of ThDP. While modest activities resulted from addition of MeOThDP to E. coli PDHc (6-11%) and DXPS (9-14%), suggesting that MeOThDP-derived covalent intermediates are converted to the corresponding products (albeit with rates slower than that with ThDP), remarkably strong activity (up to 75%) resulted upon addition of the coenzyme analogue to PDHc-h. With PDHc-ec and PDHc-h, the coenzyme analogue could support all reactions, including communication between components in the complex. No functional substitution of MeOThDP for ThDP was in evidence with either OGDH-h or OGDH-ec, shown to be due to tight binding of ThDP.
Fully continuous flow preparation method of 3-chloro-4-amyl oxoacetate
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Paragraph 0005; 0037-0052, (2021/06/22)
The invention belongs to the technical field of organic chemical engineering, and particularly relates to a fully continuous flow preparation method of 3-chloro-4-amyl oxoacetate. The method comprises the following steps of simultaneously conveying chlorine and a reaction solution of acetyl butyrolactone into a micro-channel reactor, and carrying out continuous chlorination reaction to obtain alpha-acetyl-alpha-chloro-gamma-butyrolactone, then continuously conveying the reaction liquid and a mixed solution of glacial acetic acid, hydrochloric acid and water to a micro-reaction system consisting of a next micro-mixer and a micro-channel reactor at the same time, and carrying out continuous acylation reaction to obtain 3-chloro-4-amyl oxoacetate finally, acquiring a final product in a micro-channel system of continuous quenching and continuous extraction separation. Compared with a traditional intermittent kettle type synthesis method, the method disclosed by the invention is short in reaction time, high in product yield, high in automation degree, high in process continuous efficiency, high in space-time yield, low in energy consumption and easy to industrially amplify and apply.
A PROCESS FOR PREPARING AN INTERMEDIATE OF VITAMIN B1
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Paragraph 0030; 0031, (2015/11/11)
The invention provides a new process for preparing o-acyl haloketone, comprising reacting α-halo-α-acyl-butyrolactone with an organic acid in the presence of an acid catalyst and an organic solvent.
