Method for biologically synthesizing (R)-(-)-mandelic acid

Abstract

The invention provides a method for biologically synthesizing (R)-(-)-mandelic acid. The method comprises the following steps: feeding mandelonitrile into a conversion liquid, reacting at the pH value of 6.0-9.0 at a temperature of 20-40DEG C for 20-24h, stopping feeding, and continuously reacting for 2-6h to obtain (R)-(-)-mandelic acid. The conversion liquid comprises E. coli engineering bacteria containing J2315 nitrilase. (R)-(-)-mandelic acid is prepared through a J2315 nitrilase and fed mandelonitrile combination technology, so the method has the advantages of simple process route, mild reaction conditions and no pollution, allows the (R)-(-)-mandelic acid accumulation concentration of a single batch reaction to reach 2.9M and the ee value to be greater than 97%, and has good industrial application prospect.

Description

technical field [0001] The invention belongs to the technical field of bioengineering and relates to a method for biologically synthesizing (R)-(-)-mandelic acid. Background technique [0002] Mandelic acid is an extremely important chiral drug intermediate with dual functions of anti-inflammatory and bactericidal. At present, in the international market, the demand for mandelic acid is growing at an average annual rate of about 10%, especially (R)‐(‐)‐mandelic acid has long been an urgently needed product at home and abroad. [0003] (R)‐(‐)‐mandelic acid and its derivatives are important pharmaceutical intermediates for the synthesis of cyclomandelate, oxybenzazole, pemoline and other vasodilators, bactericides, and antispasmodics, and have good biological properties. Decomposability, is currently the most eye-catching acidic optical resolution agent, which can make most racemic amines and amino acids undergo optical resolution through the formation of diastereomer salts,...

AI Technical Summary

Problems solved by technology

[0005] 1. Using benzaldehyde and hydrocyanic acid as raw materials, mandelonitrile is first prepared, and then (R)‐(‐)‐mandelic acid is obtained under the action of nitrilase, but this method is only (R)‐(‐) ‐A research direction of mandelic acid production, due to the low activity of the known nitrilase, it cannot meet the requirements of industrial production at present

[0006] 2. Mandelic acid racemate is first synthesized, then esterified or aminolyzed to obtain mandelic acid ester or mandelic acid amide, and then under the action of esterification hydrolase or amidohydrolase, a single enantiomer mandelic acid is obtained, but the The method is also only a research direction for the production of (R)‐(‐)‐mandelic acid, which is currently limited by known esterification hydrolases and amidohydrolases with low activity and poor stereoselectivity, resulting in (R )‐(‐)‐Mandelic acid has low purity and cannot meet the requirements of industrial application at present

[0007] 3. Use acetophenone as a substrate to directly catalyze the synthesis of chiral mandelic acid by microorganisms with oxidoreductase, but this method is only a research direction, and is also limited by the low enzyme activity reported so far. Industrial application is difficult

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