Abstract: A method for preparing L-carnitine using a micro-reaction system. (R)-4-halo-3-hydroxybutyrate was subjected to quaternization and hydrolysis in an aqueous trimethylamine solution in the presence of an inorganic base in a micro-channel reactor to produce the L-carnitine.

Abstract: A method for preparing L-carnitine using a micro-reaction system. (R)-4-halo-3-hydroxybutyrate was subjected to quaternization and hydrolysis in an aqueous trimethylamine solution in the presence of an inorganic base in a micro-channel reactor to produce the L-carnitine.

Abstract: Disclosed herein are a carbonyl reductase variant and its use in the preparation of (R)-4-chloro-3-hydroxybutyrate. The carbonyl reductase variant is obtained by mutating phenylalanine-85 in an amino acid sequence as shown in SEQ ID NO:4 to methionine. An amino acid or amino acids at one or more positions other than position 85 in the amino acid sequence of the carbonyl reductase may be further replaced. The application also provides a recombinant expression vector carrying the gene encoding the carbonyl reductase variant, a genetically-engineered bacterium carrying the carbonyl reductase variant gene and glucose dehydrogenase gene, and an application of this bacterium in the asymmetric reduction of 4-chloroacetoacetate to prepare (R)-4-chloro-3-hydroxybutyrate.

Abstract: The present disclosure relates to the technical field of biochemical engineering and particularly discloses a preparation method for (R)-3-hydroxyl-5-hexenoate. In the method of the present disclosure, the (R)-3-hydroxyl-5-hexenoate is prepared by catalytic reduction of 3-carbonyl-5-hexenoate by ketoreductase with 3-carbonyl-5-hexenoate as the substrate. The amino acid sequence of ketoreductase is shown in SEQ ID NO.1. In the present disclosure, the (R)-3-hydroxyl-5-hexenoate having a very high chiral purity is obtained by asymmetric reduction by ketoreductase as the biocatalyst. The present disclosure has the advantages of easy operation, mild reaction conditions, high reaction yield and good practical industrial application value.

Abstract: The present disclosure relates to the technical field of biochemical engineering and particularly discloses a preparation method for (R)-3-hydroxyl-5-hexenoate. In the method of the present disclosure, the (R)-3-hydroxyl-5-hexenoate is prepared by catalytic reduction of 3-carbonyl-5-hexenoate by ketoreductase with 3-carbonyl-5-hexenoate as the substrate. The amino acid sequence of ketoreductase is shown in SEQ ID NO.1. In the present disclosure, the (R)-3-hydroxyl-5-hexenoate having a very high chiral purity is obtained by asymmetric reduction by ketoreductase as the biocatalyst. The present disclosure has the advantages of easy operation, mild reaction conditions, high reaction yield and good practical industrial application value.