Abstract

Two pathways of combined chemical and biocatalytic synthesis of the antibiotic cefazolin (CEZ) from 7-amino-cephalosporanic acid (7-ACA) with the immobilized recombinant cephalosporin-acid synthetase as the biocatalyst are compared. The first pathway involved chemical substitution with 2-mercapto-5-methylthiadiazole to modify the 3-acetoxy group in 7-ACA with subsequent biocatalytic acylation of the amino group of the product, 7-amino-3-[2-methyl-1,3,4-thiadiazol-5-yl)-thiomethyl]-3-cephem-4-carboxylic acid (TDA), with the methyl ester of 1(Н)-tetrazolylacetic acid. An alternative pathway involved biocatalytic acylation of the 7-ACA amino group to form an intermediate (S-p CEZ) that was chemically transformed into CEZ at the next step without isolation from the reaction mix. Analysis and optimization of each of the biocatalytic processes showed that 7-ACA acylation had a number of important advantages over TDA acylation with respect to the process yield, final concentration of the product in the reaction mix, and the tolerance of the process conditions with respect to enzyme activity and stability. Given the obvious environmental advantages of the process of chemical S-p CEZ transformation into CEZ over the process of TDA production from 7-ACA, we conclude that the second pathway of combined chemical and biocatalytic CEZ synthesis is preferable.

中文翻译：

---

头孢菌素酸合成酶替代头孢唑啉的合成

摘要

比较了固定化的重组头孢菌素-酸合成酶作为生物催化剂，由7-氨基头孢菌酸（7-ACA）化学合成和生物催化合成头孢唑啉（CEZ）的两种途径。第一条途径涉及用2-巯基-5-甲基噻二唑进行化学取代，以修饰7-ACA中的3-乙酰氧基，随后对产物7-氨基-3- [2-甲基-1]的氨基进行生物催化酰化， 3，4-噻二唑-5-基-硫代甲基] -3-cephem-4-羧酸（TDA），带有1（Н）-四唑基乙酸的甲酯。另一种途径涉及7-ACA氨基的生物催化酰化反应，形成中间体（Sp CEZ），该中间体在下一步无需从反应混合物中分离就可化学转化为CEZ。对每个生物催化过程的分析和优化表明，就工艺产量，反应混合物中产物的最终浓度以及工艺条件的耐受性而言，7-ACA酰化与TDA酰化相比具有许多重要优势。对酶的活性和稳定性。鉴于化学Sp CEZ转化为CEZ的过程比7-ACA的TDA生产过程具有明显的环境优势，我们得出结论，化学和生物催化CEZ合成的第二条途径是可取的。