Schoevaart R, van Rantwijk F, Sheldon R A
Laboratory of Organic Chemistry and Catalysis, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
J Org Chem. 2000 Oct 20;65(21):6940-3. doi: 10.1021/jo000492y.
A total of four enzymatic steps were combined, in a one-pot reaction, to synthesize carbohydrates starting from glycerol. First, phosphorylation of glycerol by reaction with pyrophosphate in the presence of phytase at pH 4.0 in 95% glycerol afforded racemic glycerol-3-phosphate in 100% yield. The L-enantiomer of the latter underwent selective aerobic oxidation to dihydroxyacetone phosphate (DHAP) at pH 7.5 in the presence of glycerolphosphate oxidase (GPO) and catalase. Subsequently, fructose-1,6-bisphosphate aldolase catalyzed the aldol reaction of DHAP with butanal. Finally, dephosphorylation of the aldol adduct was mediated by phytase at pH 4 affording 5-deoxy-5-ethyl-D-xylulose in 57% yield from L-glycerol-3-phosphate. The phytase on/off-switch by pH was the key to controlling phosphorylation and dephosphorylation.
总共四个酶促步骤在一锅反应中结合起来，从甘油开始合成碳水化合物。首先，在pH 4.0的95%甘油中，在植酸酶存在下，甘油与焦磷酸反应进行磷酸化，以100%的产率得到外消旋甘油-3-磷酸。后者的L-对映体在甘油磷酸氧化酶（GPO）和过氧化氢酶存在下，于pH 7.5进行选择性好氧氧化生成磷酸二羟丙酮（DHAP）。随后，果糖-1,6-二磷酸醛缩酶催化DHAP与丁醛的醛醇缩合反应。最后，在pH 4时，植酸酶介导醛醇加合物的去磷酸化反应，从L-甘油-3-磷酸以57%的产率得到5-脱氧-5-乙基-D-木酮糖。通过pH值控制植酸酶的开启和关闭是控制磷酸化和去磷酸化的关键。
