Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilov St., 119991 Moscow, Russian Federation.
Org Biomol Chem. 2018 Mar 28;16(12):2156-2163. doi: 10.1039/c8ob00223a. Epub 2018 Mar 9.
Nucleoside phosphorylases are involved in the salvage pathways of nucleoside biosynthesis and catalyze the reversible reaction of a nucleobase with α-d-ribose-1-phosphate to yield a corresponding nucleoside and an inorganic phosphate. The equilibrium of these reactions is shifted towards nucleosides, especially in the case of purines. Purine nucleoside phosphorylase (PNP, EC 2.4.2.1) is widely used in labs and industry for the synthesis of nucleosides of practical importance. Bacterial PNPs have relatively broad substrate specificity utilizing a wide range of purines with different substituents to form the corresponding nucleosides. To shift the reaction in the opposite direction we have used arsenolysis instead of phosphorolysis. This reaction is irreversible due to the hydrolysis of the resulting α-d-ribose-1-arsenate. As a result, heterocyclic bases are formed in quantitative yields and can be easily isolated. We have developed a novel method for the preparation of cytokinins based on the enzymatic cleavage of the N-glycosidic bond of N-substituted adenosines in the presence of PNP and NaHAsO. According to the HPLC analysis the conversion proceeds in quantitative yields. In the proposed strategy the ribose residue acts as a protective group. No contamination of the final products with AsO has been detected via HPLC-HRMS; simple analytical arsenate detection via ESI-MS has been proposed.
核苷磷酸化酶参与核苷生物合成的补救途径，催化碱基与 α-d-核糖-1-磷酸的可逆反应，生成相应的核苷和无机磷酸。这些反应的平衡有利于核苷，特别是嘌呤的情况。嘌呤核苷磷酸化酶（PNP，EC 2.4.2.1）在实验室和工业中广泛用于合成具有实际重要性的核苷。细菌 PNP 具有相对较宽的底物特异性，利用具有不同取代基的广泛嘌呤形成相应的核苷。为了使反应向相反方向移动，我们使用了砷解而不是磷酸解。由于生成的 α-d-核糖-1-砷酸盐的水解，该反应是不可逆的。结果，杂环碱基以定量产率形成，并且可以容易地分离。我们已经开发了一种基于在 PNP 和 NaHAsO 的存在下切割 N-取代腺苷的 N-糖苷键的新型细胞分裂素制备方法。根据 HPLC 分析，转化率以定量产率进行。在所提出的策略中，核糖残基充当保护基团。通过 HPLC-HRMS 未检测到最终产物与 AsO 的污染；已经提出了通过 ESI-MS 进行简单的分析性砷酸盐检测。
