The present disclosure provides engineered ketoreductase enzymes having improved properties as compared to a naturally occurring wild-type ketoreductase enzyme. Also provided are polynucleotides encoding the engineered ketoreductase enzymes, host cells capable of expressing the engineered ketoreductase enzymes, and methods of using the engineered ketoreductase enzymes to synthesize a variety of chiral compounds.

The present disclosure relates to engineered ketoreductase polypeptides for the preparation of hydroxyl substituted carbamate compounds, and polynucleotides, vectors, host cells, and methods of making and using the ketoreductase polypeptides.

The present disclosure relates to engineered ketoreductase polypeptides for the preparation of hydroxyl substituted carbamate compounds, and polynucleotides, vectors, host cells, and methods of making and using the ketoreductase polypeptides.

The invention discloses an alcohol dehydrogenase mutant and use thereof. The alcohol dehydrogenase mutant of the present invention has high thermal stability and enables high catalytic efficiency and high conversion rate (i.e. space time yield) in the asymmetric reduction of prochiral diaryl ketones to produce chiral diaryl alcohols. Therefore, the alcohol dehydrogenase mutant of the present invention has extremely high prospect of application in the production of chiral diaryl alcohols, such as (S)-(4-chlorophenyl)-(pyridin-2-yl)-methanol, (R)-(4-chlorophenyl)-(pyridin-2-yl)-methanol.

The invention relates to the field of pharmaceutical synthesis, in particular to a preparation method of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol derivatives and their intermediates. The preparation method is carried out starting from compound Formula A1. ##STR00001## In the preparation of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol derivatives, the chirality was constructed by enzymatic method, and the products were prepared with high optical purity. The preparation method can be used to produce the key intermediates of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol of darunavir commercially, which is a very economical route suitable for industrial production.

Disclosed are a ketoreductase mutant and a method for producing a chiral alcohol. The ketoreductase mutant has an amino acid sequence obtained by the mutation of the amino acid sequence shown in SEQ ID NO: 1, and the mutation includes a mutation siteK200H. In the present disclosure, the mutant obtained by mutation takes a ketone compound as a raw material, the chiral alcohol may be efficiently produced by stereoselective reduction, and the stability is greatly improved, which is suitable for popularization and application to the industrial production of the chiral alcohol.

The present invention relates to an enzymatic process for preparation of optically pure enantiomers of homopropargylic alcohol compounds of formula I, which are useful intermediates for the synthesis of Halichondrin B and analogs. wherein, P is H or an alcohol protecting group, n is an integer ranging from 0-12.

##STR00001##

The present invention relates to regioselective chemical and electrochemical processes for the preparation of an oxidized heterocyclic alpha-amino amide compounds. By applying specific catalysts or catalyst systems during chemical oxidation or by applying particular electrochemical oxidation conditions the present invention provides access to valuable alpha amino amide compounds, which are oxidized at the heterocyclic amino group by regioselective introduction of either a hydroxyl or a keto group. In a more particular embodiment, the present invention describes a chemical oxidation reaction, which advantageously is applicable in the enantioselective synthesis of valuable oxidized heterocyclic alpha-amino amide compounds, like levetiracetam, brivaracetam or the synthesis of piracetam. Another aspect of the present invention relates to a process for the electrochemical recycling of alkali perhalogenate oxidants as spent during said regioselective oxidation reactions of the invention. Still another aspect of the invention relates to the electrochemical preparation of perhalogenates.

The present invention discloses a method for preparing L-glufosinate ammonium by biological enzymatic de-racemization, a glufosinate ammonium dehydrogenase mutant and a use thereof. The method for preparing L-glufosinate ammonium by biological enzymatic de-racemization includes catalyzing D,L-glufosinate ammonium as a raw material by a multi-enzyme catalysis system to obtain L-glufosinate ammonium. The enzyme catalysis system includes D-amino acid oxidase for catalyzing D-glufosinate ammonium in the D,L-glufosinate ammonium to 2-carbonyl-4-[hydroxy(methyl)phosphonyl]butanoic acid, and a glufosinate ammonium dehydrogenase mutant for catalytically reducing 2-carbonyl-4-[hydroxy(methyl)phosphonyl]butanoic acid to L-glufosinate ammonium. The glufosinate ammonium dehydrogenase mutant is obtained by mutation of glufosinate-ammonium dehydrogenase in wild fungi Thiopseudomonas denitrificans at a mutation site of V377S. The glufosinate ammonium dehydrogenase mutant in the present invention has better catalytic efficiency. When racemic D, L-glufosinate ammonium is used as a substrate for a catalytic reaction, the conversion rate is much higher than the conversion rate of a wild-type enzyme, and the yield of 2-carbonyl-4-[hydroxy(methyl)phosphonyl]butanoic acid (PPO for short) is also greatly improved.

The present invention refers to a modified D-amino acid oxidase (DAAO). In particular, the modified DAAO of the present invention has the activity of catalyzing the oxidation of D-glufosinate into PPO. Further, the modified DAAO of the present invention has increased activity of catalyzing the oxidation of D-glufosinate into PPO and/or increased stability as compared to SEQ ID NO: 4. The present invention also refers to the polynucleotide encoding the modified DAAO of the present invention, the vector and host cell expressing the modified DAAO of the present invention, and the method of producing L-glufosinate with the modified DAAO and host cell of the present invention.