郁李仁(R)-醇腈酶高效催化乙酰基三甲基硅烷与丙酮氰醇不对称转氰

Highly efficient asymmetric transcyanation of acetyltrimethylsilane with acetone cyanohydrin in an aqueous/organic biphasic system catalyzed with(R)-oxynitrilase from defatted Prunus Japonica seed meal for the preparation of optically active(R)-2-trimethylsilyl-2-hydroxyl-propionitrile was successfully carried out for the first time.For better understanding of the reaction,various influential variables were examined with respect to the initial reaction rate,the substrate conversion and the product enantiomeric excess(e.e.).Diisopropyl ether was found to be the best organic phase for this reaction among all the organic solvents tested.The optimal concentrations of Prunus Japonica seed meal powder,acetyltrimethylsilane and acetone cyanohydrin,volume ratio of aqueous phase to organic phase,buffer pH value and the reaction temperature were 34. 5 g.L~(-1) and 14 mmol·L~(-1) ,28 mmol.L~(-1) , 13%(by volume),5. 0 and 30℃,respectively,while the initial reaction rate,the substrate conversion and the product enantiomeric excess were 1. 34 mmol.L~(-1) .h~(-1) ,99. 0% and 99. 0%,respectively.The comparative study demonstrated that silicon atom in substrate showed great effect on the reaction and acetyltrimethylsilane was a much better substrate for(R)-hydroxynitrile lyase from Prunus Japonica seed than its carbon analogue 3,3-dimethyl-2-butanone.     

郁李仁（R）-醇腈酶高效催化乙酰基三甲基硅烷与丙酮氰醇不对称转氰

Highly efficient asymmetric transcyanation of acetyltrimethylsilane with acetone cyanohydrin in an aqueous/organic biphasic system catalyzed with （R）-oxynitrilase from defatted Prunus Japonica seed meal for the preparation of optically active （R）-2-trimethylsilyl-2-hydroxyl-propionitrile was successfully carried out for the first time. For better understanding of the reaction, various influential variables were examined with respect to the initial reaction rate, the substrate conversion and the product enantiomeric excess （e.e.）. Diisopropyl ether was found to be the best organic phase for this reaction among all the organic solvents tested. The optimal concentrations of Prunus Japonica seed meal powder, acetyltrimethylsilane and acetone cyanohydrin, volume ratio of aqueous phase to organic phase, buffer pH value and the reaction temperature were 34.5g·L^-1 and 14mmol· L^-1, 28mmol· L^-1, 13% （by volume）, 5.0 and 30℃, respectively, while the initial reaction rate, the substrate conversion and the product enantiomeric excess were 1.34 mmol·L^-1·h^-1, 99.0% and 99.0%, respectively. The comparative study demonstrated that silicon atom in substrate showed great effect on the reaction and acetyltrimethylsilane was a much better substrate for （R）-hydroxynitrile lyase from Prunus Japonica seed than its carbon analogue 3,3-dimethyl-2-butanone.     

葡萄酒沉淀种类及其处理方法

葡萄酒属于电解质平衡状态饮料酒,常常因为条件的变化而发生浑浊或沉淀。通过综合研究,分析葡萄酒常见浑浊与沉淀机理,有针对性地预防,对延长酒体稳定期有积极作用。     

大豆蛋白的营养及其饮料的生产

论述了大豆蛋白的营养及大豆蛋白饮料的生产工艺流程。     

大豆蛋白的营养及其饮料的生产

论述了大豆蛋白的营养及大豆蛋白饮料的生产工艺流程。     

新型豆腐的制备方法

豆腐是我国的传统食品 ,正受到世界各国的青睐。本文介绍了一些新型豆腐的制备方法。     

源于大豆的功能性食品添加物

介绍了来源于大豆的功能性食品添加物（如大豆蛋白、大豆多肽、大豆低聚糖、大豆磷脂、大豆纤维和大豆异黄酮）的性质、功能和应用。     

源于大豆的功能性食品添加物

介绍了来源于大豆的功能性食品添加物（如大豆蛋白、大豆多肽、大豆低聚糖、大豆磷脂、大豆纤维和大豆异黄酮）的性质、功能和应用。     

新型豆腐的制备方法

豆腐是我国的传统食品，正受到世界各国的青睐。本文介绍了一些新型豆腐的制备方法。