Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland.
ChemSusChem. 2022 Jan 10;15(1):e202102030. doi: 10.1002/cssc.202102030. Epub 2021 Nov 27.
The continuous synthesis of valuable nucleoside drugs was achieved in up to 99 % conversion by using a novel halotolerant purine nucleoside phosphorylase from Halomonas elongata (HePNP). HePNP showed an unprecedented tolerance to DMSO, usually required for substrate solubility, and could be immobilized on agarose microbeads through disulfide bonds, via a genetically fused Cystag. This covalent yet reversible binding chemistry showcased the reusability of agarose microbeads in a second round of enzyme immobilization with high reproducibility, reducing waste and increasing the sustainability of the process. Finally, the flow synthesis of a Nelarabine analogue (6-O-methyl guanosine) was optimized to full conversion on a 10 mm scale within 2 min residence time, obtaining the highest space-time yield (89 g L h ) reported to date. The cost-efficiency of the system was further enhanced by a catch-and-release strategy that allowed to recover and recirculate the excess of sugar donor from the downstream water waste.
新型耐盐嗜盐单胞菌嘌呤核苷磷酸化酶（HePNP）可实现高达 99%转化率的有价值核苷类药物的连续合成。HePNP 对二甲基亚砜（DMSO）具有前所未有的耐受性，DMSO 通常是底物溶解所必需的，并且可以通过半胱氨酸融合的 Cystag 通过二硫键固定在琼脂糖微珠上。这种共价但可逆的结合化学展示了琼脂糖微珠在第二轮酶固定化中的可重复使用性，具有很高的重现性，减少了浪费并提高了该过程的可持续性。最后，通过优化流动合成，在 2 分钟的保留时间内将奈拉滨类似物（6-O-甲基鸟苷）的合成优化至完全转化，获得了迄今为止报道的最高时空产率（89 g·L-1·h-1）。通过一种捕获-释放策略进一步提高了该系统的成本效益，该策略允许从下游废水回收和再循环过量的糖供体。
