Iterative Alanine Scanning Mutagenesis Confers Aromatic Ketone Specificity and Activity of L-Amine Dehydrogenases
Direct reductive amination of prochiral ketones catalyzed by amine dehydrogenases is attractive in the synthesis of active pharmaceutical ingredients. Here, we report the protein engineering of L-Bacillus cereus amine dehydrogenase to allow reactivity on synthetically useful aromatic ketone substrates using an iterative, multiple-site alanine scanning mutagenesis approach. Mutagenesis libraries based on molecular docking, iterative alanine scanning, and double-proximity filter approach significantly expand the scope of active pharmaceutical ingredients relevant building blocks. The eventual quintuple mutant (A115G/T136A/L42A/V296A/V293A) showed reactivity toward aromatic ketones 12 a (5-phenyl-pentan-2-one) and 13 a (6-phenyl-hexan-2-one), which have not been reported to serve as targets of reductive amination by currently available amine dehydrogenases. Docking simulation and tunnel analysis provided valuable insights into the source of the acquired specificity and activity.
Mu, Xiaoqing,Wu, Tao,Mao, Yong,Zhao, Yilei,Xu, Yan,Nie, Yao
p. 5243 - 5253
(2021/11/16)
Improved synthetic method of (R)-1-aryl-2-propylamine
The invention provides an improved synthetic method of (R)-1-aryl-2-propylamine. The improved synthetic method comprises the following steps of: adopting 1-arylacetone as a raw material, adding (R)-1-phenylethylamine, carrying out reductive amination reaction with hydrogen under a common action of a Lewis acid additive and a transitional metal hydrogenation catalyst; carrying out Pd/C catalytic hydrogenation on an obtained intermediate to remove phenethyl on nitrogen and thus obtaining (R)-1-aryl-2-propylamine. The improved synthetic method provided by the invention has the beneficial effectsthat the operation is simple, the adopted Lewis acid additive is low in cost and easy in obtaining, the yield and the enantioselectivity of a product are high, and the application value for industrialsynthesis of (R)-1-aryl-2-propylamine is very high.
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Paragraph 0035; 0036; 0038; 0049
(2018/07/30)
Enzymatic enantiomeric resolution of phenylethylamines structurally related to amphetamine
Both enantiomers of several phenylethylamines, structurally related to amphetamine, have been prepared in good yields and excellent enantiomeric purity by enzymatic kinetic resolution using CAL-B and ethyl methoxyacetate as the acyl donor. In the case of the 4-hydroxyderivative of amphetamine (compound 4i), the S enantiomer racemized possibly in a dynamic kinetic resolution (DKR) under the enzymatic conditions used. The Royal Society of Chemistry 2011.
Munoz, Lourdes,Rodriguez, Anna M.,Rosell, Gloria,Bosch, M. Pilar,Guerrero, Angel
p. 8171 - 8177
(2012/01/04)
Microbial Hydrogenation of Nitroolefins
Micriorganisms which hydrogenate 2-nitro-1-phenyl-1-propene were screend in type cultures and soil samples.Some actinomycetes belonging to Rhodococcus, Nocardia and Mycobacterium asymmetrically reduced the substrate and gave optically active 2-nitro-1-phenylpropane.Among them, Rhodococcus rhodochrous IFO 3338 gave the best results.The satureted compound was obtained quantitatively, when cultivation was carried out for 3 days at 30 oC with a substrate concentration of 0.4percent.The optical purity of the product was seriously affected by the pH of the medium.The more acidic the medium, the higher the enantiomeric excess.The results suggested that non-enzymatic racemization of the product take place even under neutral conditions.Other substrates, such as 2-nitro-1-propene were also converted to optically active 2-nitro-1-substituted propane.