Abstract: In a process for the stereoselective, in particular enantioselective enzymatic reduction of keto compounds to the corresponding chiral hydroxy compounds, wherein the keto compounds are reduced with an enantioselective, NADH-specific oxidoreductase, a polypeptide is used for reducing the keto compounds, which polypeptide exhibits an R-ADH-signature H-[P; A]-[I; A; Q; V; L]-[G; K]-R at positions 204-208 and the following further structural features in their entirety: (i) an N-terminal Rossmann-Fold GxxxGxG, (ii) an NAG-motif at position 87, (iii) a catalytic triad consisting of S 139, Y 152 and K 156, (iv) a negatively charged amino acid moiety at position 37, (v) two C-terminal motifs in the dimerization domain [A; S]-S-F and [V; I]-DG-[G; A]-Y-[T; C; L]-[A; T; S]-[Q; V; R; L; P], (vi) Val or Leu at position 159 (4 positions downstream of K 156), (vii) Asn at position 178, and (viii) a proline moiety at position 188.

Abstract: The invention relates to a process for the enantioselective enzymatic reduction of a keto compound to the corresponding chiral hydroxy compound, wherein the keto compound is reduced with an oxidoreductase in the presence of a cofactor, and is characterized in that an oxidoreductase is used which has an amino acid sequence in which (a) at least 70% of the amino acids are identical to the amino acids of one of the amino acid sequences SEQ ID No 1, SEQ ID No 6 and SEQ ID No 8, or (b) at least 55% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 2, or (c) at least 65% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 3, or (d) at least 75% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 4, or (e) at least 65% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 5, or (0 at least 50% of the amino acids are identical to the amino acids of the amino acid sequence

Abstract: In a process for the enantioselective enzymatic reduction of a hydroxy ketone of general formula I wherein R1=C1-C6 alkyl and R2=—Cl, —CN, —OH, —H or C1-C6 alkyl, into a chiral diol of general formula II wherein R1 and R2 have the same meaning as in formula I, the hydroxy ketone is reduced with an oxidoreductase in the presence of NADH or NADPH as a cofactor, wherein a) the hydroxy ketone is provided in the reaction at a concentration of ?50 g/l, b) the oxidized cofactor NAD or NADP having formed is regenerated continuously by oxidation of a secondary alcohol of general formula RXRYCHOH, wherein RX, RY independently represent hydrogen, branched or unbranched C1-C8-alkyl and Ctotal?3, and c) the reduction of the hydroxy ketone and the oxidation of the secondary alcohol are catalyzed by the same oxidoreductase.

Abstract: A process for the enantioselective enzymatic reduction of a keto compound of general formula I wherein R may represent any protective group for amino functions (tert. butyloxycarbonyl group (BOC), benzyloxycarbonyl group, 9-fluorenylmethoxycarbonyl group) and X?—Cl, —CN, —OH, Br, F.

Abstract: The invention relates to a process for the enantioselective enzymatic reduction of a keto compound to the corresponding chiral hydroxy compound, wherein the keto compound is reduced with an oxidoreductase in the presence of a cofactor, and is characterized in that an oxidoreductase is used which has an amino acid sequence in which (a) at least 70% of the amino acids are identical to the amino acids of one of the amino acid sequences SEQ ID No 1, SEQ ID No 6 and SEQ ID No 8, or (b) at least 55% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 2, or (c) at least 65% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 3, or (d) at least 75% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 4, or (e) at least 65% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 5, or (0 at least 50% of the amino acids are identical to the amino acids of the amino acid sequence

Abstract: The invention relates to a process for the enantioselective enzymatic reduction of secodione derivatives. The secodione derivative is reduced with an oxidoreductase/dehydrogenase in the presence of NADH or NADPH as a cofactor. The secodione derivative is used in the reaction batch at a concentration of ?10 g/l and the oxidized cofactor NAD or NADP formed by the oxidoreductase/dehydrogenase is regenerated continuously.

Abstract: A process for the enantioselective reduction of compounds having a steroid structure (ABCD) including one or several heteroatoms, one or several double bonds and/or aromatic components in the ring structure and having at least one oxo group at positions 3, 7, 11, 12 or 17 in the steroid ring system or in the a-position of any carbon moiety of the steroid structure: comprising providing the oxosteroid compound in the reaction at a concentration of ?50 g/L, a reduced cofactor NADH or NADPH, a hydroxysteroid dehydrogenase and a secondary alcohol or cycloalknaol to effect the enantioselective reduction.

Abstract: The present invention relates to a process for the enantioselective enzymatic reduction of keto compounds, in particular of 4-halo-3-oxobutyric acid esters, to the corresponding R-alcohols or S-4-halo-3-hydroxybutyric acid esters, respectively, using an R-specific oxidoreductase in the presence of a cofactor.

Abstract: The invention relates to a process for the enantioselective enzymatic reduction of secodione derivatives. The secodione derivative is reduced with an oxidoreductase/dehydrogenase in the presence of NADH or NADPH as a cofactor. The secodione derivative is used in the reaction batch at a concentration of ?10 g/l and the oxidized cofactor NAD or NADP formed by the oxidoreductase/dehydrogenase is regenerated continuously.

Abstract: In a process for the stereoselective, in particular enantioselective enzymatic reduction of keto compounds to the corresponding chiral hydroxy compounds, wherein the keto compounds are reduced with an enantioselective, NADH-specific oxidoreductase, a polypeptide is used for reducing the keto compounds, which polypeptide exhibits an R-ADH-signature H-[P; A]-[I; A; Q; V; L]-[G; K]-R at positions 204-208 and the following further structural features in their entirety: (i) an N-terminal Rossmann-Fold GxxxGxG, (ii) an NAG-motif at position 87, (iii) a catalytic triad consisting of S 139, Y 152 and K 156, (iv) a negatively charged amino acid moiety at position 37, (v) two C-terminal motifs in the dimerization domain [A; S]-S-F and [V; I]-DG-[G; A]-Y-[T; C; L]-[A; T; S]-[Q; V; R; L; P], (vi) Val or Leu at position 159 (4 positions downstream of K 156), (vii) Asn at position 178, and (viii) a proline moiety at position 188.

Abstract: The invention relates to a process for the enantioselective enzymatic reduction of secodione derivatives. The secodione derivative is reduced with an oxidoreductase/dehydrogenase in the presence of NADH or NADPH as a cofactor. The secodione derivative is used in the reaction batch at a concentration of ?10 g/l and the oxidized cofactor NAD or NADP formed by the oxidoreductase/dehydrogenase is regenerated continuously.

Abstract: A process for the enantioselective enzymatic reduction of a keto compound of general formula I wherein R may represent any protective group for amino functions (tert. butyloxycarbonyl group (BOC), benzyloxycarbonyl group, 9-fluorenylmethoxycarbonyl group) and X?—Cl, —CN, —OH, Br, F.

Abstract: The invention relates to a process for the enantioselective enzymatic reduction of a keto compound to the corresponding chiral hydroxy compound, wherein the keto compound is reduced with an oxidoreductase in the presence of a cofactor, and is characterized in that an oxidoreductase is used which has an amino acid sequence in which (a) at least 70% of the amino acids are identical to the amino acids of one of the amino acid sequences SEQ ID No 1, SEQ ID No 6 and SEQ ID No 8, or (b) at least 55% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 2, or (c) at least 65% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 3, or (d) at least 75% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 4, or (e) at least 65% of the amino acids are identical to the amino acids of the amino acid sequence SEQ ID No 5, or (f) at least 50% of the amino acids are identical to the amino acids of the amino acid sequenc

Abstract: A process for the enantioselective enzymatic reduction of compounds which comprise a steroid structure (ABCD) including one or several heteroatoms, one or several double bonds and/or one aromatic component in the ring structure and have at least one oxo group at position 3, 7, 11, 12 or 17 in the steroid ring system or in the ?-position at any carbon moiety on the steroid skeleton (=oxosteroid compound), wherein the oxosteroid compound is reduced with a hydroxysteroid dehydrogenase in the presence of a cofactor NADH or NADPH, is characterized in that a) the oxosteroid compound is provided in the reaction at a concentration of ?50 g/l, b) the oxidized cofactor NAD or NADP formed by the hydroxysteroid dehydrogenase is regenerated continuously by oxidation of a secondary alcohol of general formula RXRYCHOH, wherein RX, RY independently represent hydrogen, a branched or unbranched C1-C8-alkyl and Ctotal?3, or by oxidation of a C4-C6-cycloalkanol, and c) an additional oxidoreductase/alcohol dehydrogenase is u

Abstract: In a process for the enantioselective enzymatic reduction of a hydroxy ketone of general formula I wherein R1=C1-C6alkyl and R2=—Cl, —CN, —OH, —H or C1-C6 alkyl, into a chiral diol of general formula II wherein R1 and R2 have the same meaning as in formula I, the hydroxy ketone is reduced with an oxidoreductase in the presence of NADH or NADPH as a cofactor, wherein a) the hydroxy ketone is provided in the reaction at a concentration of ?50 g/l, b) the oxidized cofactor NAD or NADP having formed is regenerated continuously by oxidation of a secondary alcohol of general formula RXRYCHOH, wherein RX, RY independently represent hydrogen, branched or unbranched C1-C8-alkyl and Ctotal?3, and c) the reduction of the hydroxy ketone and the oxidation of the secondary alcohol are catalyzed by the same oxidoreductase.

Abstract: The invention relates to a NADH-dependent oxidoreductase obtained from yeasts, for example, of the genus Pichia, more particularly from Pichia capsulata. The oxidoreductace used in an enzymatic process for enantioselective reduction of organic ketocompounds to the corresponding (S)-hydroxy compounds and in an enzymnatic process for an antioselective preparation of (S)-hydroxy compounds in a two phase system using the isolated, recombinantly overexpressed oxidoreductacse from Pichia capsulata.

Abstract: The invention relates to a method for producing an enantiopure alcohol of general formula (Ia) or (Ib), wherein R1, R2, R3, R4, R5 and R6 each represent hydrogen, halogen, a C1-C6 alkyl or C1-C6 alkoxy group, with the proviso that at least one of the groups R1, R2, R3, R4, R5 and R6 is different from the remaining five groups and with the additional proviso that at least one of the groups R1, R2, R3, R4, R5 and R6 is a halogen. The invention is characterized in that a ketone of general formula (II), wherein R1, R2, R3, R4, R5 and R6 are defined as above, is enzymatically reduced in the presence of an S-specific or R-specific dehydrogenase/oxidoreductase using NADH or NADPH as the cofactor.

Abstract: The present invention relates to a process for the enantioselective enzymatic reduction of keto compounds which is carried out in two phases and uses 4-methyl-2-pentanol, 5-methyl-2-hexanol and/or 2-heptanol for coenzyme regeneration.

Abstract: The present invention relates to a process for the enantioselective enzymatic reduction of keto compounds, in particular of 4-halo-3-oxobutyric acid esters, to the corresponding R-alcohols or S-4-halo-3-hydroxybutyric acid esters, respectively, using an R-specific oxidoreductase in the presence of a cofactor.

Abstract: The invention relates to a process for the preparation of 2-butanol by enzymatic-catalyzed reduction of 2-butanone with a carbonyl reductase and a coenzyme and is characterized in that an aqueous phase, which contains the carbonyl reductase and the coenzyme, is contacted with an alcoholic phase, which is not miscible with the aqueous phase and contains 2-butanone, in order to reduce the 2-butanone, with the proviso that the alcohol present in the alcoholic phase is a secondary alcohol capable of regenerating the coenzyme and exhibiting a boiling point which lies above that of water, whereupon the 2-butanol formed is separated.