Biotransformation of 5´-O-β-D-galactosyl-floxuridine by immobilized β-galactosidase from Kocuria rhizophila

Abstract

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.