Sodium Alginate catalytic asymmetric synthesis of baker's yeast (S) - () -1 - phenyl - 2 - propanol
|School||Central South University|
|Keywords||Baker's yeast (S) - () -1 - phenyl - 2 - propanol Asymmetric reduction Immobilization|
(S) - () -1 - phenyl - 2 - propanol hydrochloride synthesis of optically active amphetamines, (R) - selegiline, cathepsin K (cathepsin K) inhibitors and benzodiazepines important intermediate compounds, present (S) - () -1 - phenyl - 2 - propanol mainly chemical catalysis, enzymatic reduction, enzymatic resolution method and microbial living cells such as catalytic reduction method, but Few on the baker's yeast immobilized catalytic reduction method reported. In this thesis, baker's yeast catalytic reduction fixed alginate phenyl acetone synthesis (S) - () -1 - phenyl - 2 - propanol, main contents and results are as follows: The effects of baker's yeast stereoselective catalytic phenyl acetone asymmetric reduction reaction characteristics, established by gas chromatography (GC) phenyl acetone conversion rate determined, IR and ~ 1HMNR method (S) - () -1 - phenyl - 2 - propanol and characterization of structures ( S) - () -1 - phenyl - 2 - propanol on the enantiomeric excess (ee) is calculated with the ratio of optical rotation. First, as the substrate phenylacetone studied asymmetric reduction of free bread yeast situation investigated phenyl acetone concentration, reaction time, reaction temperature, pH, and glucose concentration on the reduction reaction. The optimum conditions: phenyl acetone concentration 3.28g / L, reaction time 22h, the reaction temperature is 25 ℃, pH value of 6.5 and glucose concentration 15g / L. Which phenyl acetone conversion was 61.6%, (S) - () -1 - phenyl - 2 - propanol is 90.4% ee. Secondly, discusses the alginate immobilized yeast bread many conditions, orthogonal experiment investigated the concentration of sodium alginate, calcium chloride concentration, immobilization temperature, volume and immobilized yeast Saccharomyces cerevisiae immobilized on time effects and determine glutaraldehyde concentration and crosslinking time. Experimental optimum conditions: the concentration of 3% sodium alginate, calcium chloride concentration of 3%, 20% of the amount of yeast, immobilization time 4h, immobilization temperature 30 ℃, the concentration of 1.5% glutaraldehyde and crosslinking time 2h. Finally, phenyl acetone as substrate of immobilized yeast bread asymmetric reduction conditions investigated phenyl acetone concentration, the amount of yeast, immobilization particle diameter, rotation speed, reaction pH, reaction temperature and reaction time reaction conditions on the reaction. The optimum conditions: phenyl acetone concentration 5.74g / L, the amount of yeast 1.5g, immobilized particle diameter 1.5mm ~ 2.0mm, shaking speed 200r/min, pH value of 7.5, reaction temperature 30 ℃ and reaction time 24h. Which phenyl acetone conversion was 62.5%, (S) - () -1 - phenyl - 2 - propanol is 90.7% ee. The same reaction conditions, the free bread yeast obtained Asymmetric Synthesis of phenyl acetone conversion was 55.9%, (S) - () -1 - phenyl - 2 - propanol is 89.7% ee. From the experimental results, the immobilized baker's yeast and yeast free bread compared to the phenyl acetone conversion rate and the (S) - () -1 - phenyl - 2 - propanol ee values ??were improved; immobilized yeast bread reused three times, still able to maintain high catalytic performance. Free bread yeast and baker's yeast can be immobilized catalytic synthesis of (S) - () -1 - phenyl - 2 - propanol, but Saccharomyces cerevisiae immobilized catalyst synthesized phenyl acetone conversion and enantiomeric excess of the product value than the free catalytic synthesis of higher baker's yeast, and the stability and resistance to substrate concentrations were increased.