- A novel strategy for efficient chemoenzymatic synthesis of D-glutamine using recombinant Escherichia coli cells
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D-glutamine is a D type stereoisomer of glutamine which is involved in many metabolic processes. Seeking lower-cost and industrially scalable approaches for the synthesis of D-glutamine is very valuable both in academic career and potential applications. Herein, we developed a novel efficient chemoenzymatic strategy for producing D-glutamine. Initially, DL-glutamine was chemically prepared with cheap and accessible DL-glutamic acid as raw material. Subsequently, the L-glutamine among the racemic mixture was selectively hydrolyzed to L-glutamic acid by Escherichia coli whole-cell system which expressed L-aminopeptidase D-Ala-esterase/amidase (DmpA) from Ochrobactrum anthropi. The left D-glutamine was obtained by isoelectric point precipitation with 70% of the theoretical yield. Furthermore, we optimized enzymatic resolution conditions to determine the optimum parameters as pH 8, 30 °C, 0.1% (v/v) Triton X-100, and 1 mM Mn2+. These results suggested that our strategy might be potentially usable for the synthesis of D-glutamine in industrial productions.
- Du, Qinglin,Zhang, Xiangyang,Pan, Xinru,Zhang, Hongjuan,Yang, Yu-Shun,Liu, Junzhong,Jiao, Qingcai
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- Sulfur ylides 13. Synthesis and intramolecular cyclization of keto-stabilized sulfur ylides
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Keto-stabilized sulfur mono-and bisylides were obtained from N-phthalylglutamic acid and their intramolecular cyclization was studied. The intramolecular cyclization of the ylide obtained at the α-carboxy group gave a product of the pyrrolizidinedione structure; bisylide yielded a cycloheptene derivative as the result of intramolecular recombination of intermediate dicarbene. The ylide obtained at the γ-carboxy group underwent no cyclization, giving methylthio ketone and oxo benzoate.
- Galin,Sakhautdinov,Lakeev,Egorov,Fatykhov,Maidanova
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p. 2867 - 2872
(2007/10/03)
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- Thalidomide metabolites and analogues. 3. Synthesis and antiangiogenic activity of the teratogenic and TNFα-modulatory thalidomide analogue 2-(2,6-dioxopiperidine-3-yl)phthalimidine
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Versatile synthesis of the teratogenic, TNFα-modulatory, and antiangiogenic thalidomide analogue 2-(2,6-dioxopiperidine-3-yl)phthalimidine (1) and its direct antiangiogenic properties are described. With thalidomide or thalidomide derivatives as precursors, the synthesis involved either carbonyl reduction/thiation-desulfurization or carbonyl reduction/acyliminium ion reduction protocols. Compared to earlier studies with thalidomide, which was only active with microsomal treatment, 1 exhibited marginal inhibitory activity in the rat aortic ring assay, thereby demonstrating the requirement for metabolic activation.
- Luzzio, Frederick A.,Mayorov, Alexander V.,Ng, Sylvia S. W.,Kruger, Erwin A.,Figg, William D.
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p. 3793 - 3799
(2007/10/03)
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- Synthesis of 3-methylaspartic acids by ring-contraction of a nickelacycle derived from glutamic anhydride
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The synthesis of protected methylaspartic acids from glutamic acid has been achieved by means of ring contraction of the derived nickelacycle followed by insertion of isocyanides.
- Echavarren, Antonio M.,Castano, Ana M.
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p. 2369 - 2378
(2007/10/02)
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