Enzyme reaction method and a method for enzymatically producing an optically active cyanohydrin

Abstract

The present invention relates to an enzyme reaction method which comprises performing an enzyme reaction, using an immobilized enzyme having a water content of 10% by weight or more as an enzyme and using an organic solvent substantially immiscible with water as a reaction solvent, under such conditions that a liquid phase forms a homogeneous system without phase separation although it is saturated with water or an aqueous buffer; a method for performing an enzyme reaction using an aldehyde compound as a substrate, which comprises removing a carboxylic acid compound contained in an aldehyde compound by subjecting the aldehyde compound to an alkaline treatment before starting the enzyme reaction; a method for performing an enzyme reaction using an aldehyde compound as a substrate, which comprises reducing a carboxylic acid compound content in the aldehyde compound to 0.1 wt % or less by subjecting the aldehyde compound to an alkaline treatment before starting the enzyme reaction; a method for enzymatically producing an optically active cyanohydrin from a carbonyl compound and prussic acid containing an acidic substance as a stabilizer, which comprises subjecting the prussic acid to a treatment for reducing inhibitory effect of the stabilizer on an enzyme, and performing an enzyme reaction to synthesize the optically active cyanohydrin using the treated prussic acid; a method for enzymatically producing an optically active cyanohydrin, which comprises dissolving prussic acid in an organic solvent substantially immiscible with water to give an organic solution of prussic acid, adding a buffer to this solution in a saturation amount or more, mixing, collecting the organic phase, and performing an enzyme reaction to synthesize the optically active cyanohydrin using the organic phase as prussic acid; as well as a method for enzymatically producing an optically active cyanohydrin, which comprises performing distillation of a reaction solution after completion of an enzyme reaction to separate and collect unreacted prussic acid and organic solvent therefrom, and repeatedly using the collected prussic acid and organic solvent at least once.

1 - 10 . (canceled)  
     
     
         11 . A method for enzymatically producing an optically active cyanohydrin from a carbonyl compound and prussic acid containing an acidic substance as a stabilizer, said prussic acid providing an aqueous phase with pH 5 or less when dissolved at a concentration of 1.5 M in an organic solvent substantially immiscible with water, mixed with pure water at such a ratio that the mixture separates into organic and aqueous phases, and then allowed to stand, wherein said method comprises: 
 subjecting said prussic acid to a treatment for reducing inhibitory effect of the stabilizer on an enzyme; and    performing an enzyme reaction to synthesize the optically active cyanohydrin using the treated prussic acid.    
     
     
         12 . A method for enzymatically producing an optically active cyanohydrin from prussic acid and carbonyl compound, which comprises: 
 dissolving prussic acid in an organic solvent substantially immiscible with water to give an organic solution of prussic acid;    adding a buffer to this solution in a saturation amount or more;    mixing;    collecting the organic phase; and    performing an enzyme reaction to synthesize the optically active cyanohydrin using the organic phase as prussic acid.    
     
     
         13 . The method according to  claim 12 , wherein the buffer has buffering ability in a range of pH 4 to pH 7.  
     
     
         14 . The method according to  claim 11 , wherein the enzyme reaction is catalyzed by hydroxynitrile lyase.  
     
     
         15 . The method according to  claim 12 , wherein the enzyme reaction is catalyzed by hydroxynitrile lyase.  
     
     
         16 . A method for enzymatically producing an optically active cyanohydrin from prussic acid and carbonyl compound, which comprises: 
 performing distillation of a reaction solution after completion of an enzyme reaction to separate and collect unreacted prussic acid and organic solvent therefrom; and    repeatedly using the collected prussic acid and organic solvent at least once.    
     
     
         17 . The method according to  claim 16 , wherein the reaction solution after completion of an enzyme reaction is obtained from the method according to claim  1 .  
     
     
         18 . The method according to  claim 16 , wherein the reaction solution after completion of an enzyme reaction is obtained from the method according to claim  5 .  
     
     
         19 . The method according to  claim 16 , wherein the reaction solution after completion of an enzyme reaction is obtained from the method according to claim  6 .  
     
     
         20 . The method according to  claim 16 , wherein the reaction solution after completion of an enzyme reaction is obtained from the method according to  claim 11 .  
     
     
         21 . The method according to  claim 16 , wherein the reaction solution after completion of an enzyme reaction is obtained from the method according to  claim 12 .  
     
     
         22 . A method of performing an enzymatic reaction, comprising: 
 treating a solution comprising an aldehyde compound with an alkaline compound to form a treated solution; and    initiating the enzymatic reaction;    wherein the aldehyde compound is a substrate for the enzymatic reaction.    
     
     
         23 . The method of  claim 22 , wherein initiating the enzymatic reaction comprises adding an enzyme and hydrogen cyanide to the treated solution.  
     
     
         24 . The method of  claim 22 , wherein the treated solution comprises 0.1 weight percent or less of a carboxylic acid, based on the total weight of the solution.  
     
     
         25 . The method of  claim 22 , wherein treating with an alkaline compound comprises: 
 combining the solution comprising the aldehyde compound with an alkaline aqueous solution to form an aqueous phase; and    separating the aqueous phase from the solution comprising the aldehyde compound.    
     
     
         26 . The method of  claim 24 , wherein treating with an alkaline compound comprises: 
 combining the solution comprising the aldehyde compound with an alkaline aqueous solution to form an aqueous phase; and    separating the aqueous phase from the solution comprising the aldehyde compound.    
     
     
         27 . The method of  claim 22 , wherein the enzymatic reaction comprises the reaction of the aldehyde compound and hydrogen cyanide to form a corresponding optically active cyanohydrin wherein the reaction is catalyzed by hydroxynitrile lyase.  
     
     
         28 . The method of  claim 24 , wherein the enzymatic reaction comprises the reaction of the aldehyde compound and hydrogen cyanide to form a corresponding optically active cyanohydrin wherein the reaction is catalyzed by hydroxynitrile lyase.