5-fluorouracil-2’-deoxyriboside (FUdR), an antimetabolite known as floxuridine, is a halogenated nucleoside extensively used in the clinical treatment of colon carcinoma and hepatic metastases. This drug presents low bioavailability, thus requiring large doses and frequent administration, which leads to long-lasting and severe side effects in clinical practice. In order to overcome this problem, galactosylated nucleoside analogues were obtained using immobilized β-galactosidase in Ca-alginate with yields of 80% at only 7 h. Additionally, the obtained biocatalyst was stable for 6 months in storage conditions (4 °C) and could be reused at least 16 times without loss of its activity at 30 °C.

This work describes for the first time an efficient, eco-compatible and simple bioprocess for obtaining 5´-O-β-d-galactosyl-floxuridine using an immobilized biocatalyst.

5-氟尿嘧啶2'-脱氧核糖苷（FUdR）是一种抗代谢物，称为氟尿苷，是一种卤化的核苷，广泛用于结肠癌和肝转移瘤的临床治疗。该药物的生物利用度低，因此需要大剂量和频繁给药，这在临床实践中导致长期和严重的副作用。为了克服这个问题，使用固定化的β-半乳糖苷酶在藻酸盐中获得了半乳糖基化的核苷类似物，仅在7小时内产率为80％。另外，所获得的生物催化剂在储存条件（4℃）下稳定6个月，并且可以重复使用至少16次而在30℃下不会丧失其活性。

这项工作首次描述了使用固定化生物催化剂获得5′-O-β- d-半乳糖基-氟尿苷的高效，生态兼容和简单的生物工艺。