Biotransformation of halogenated nucleosides by immobilized Lactobacillus animalis 2′-N-deoxyribosyltransferase

An immobilized biocatalyst with 2′-N-deoxyribosyltransferase activity (NDT) was developed from cell free extracts, resulting in a derivative with an activity of 2.6U/g for the biosynthesis of the 5-fluorouracil-2′-deoxyriboside, an antimetabolite known as floxuridine, used in gastrointestinal cancer treatment. Furthermore, immobilized NDT was satisfactorily used to obtain other halogenated pyrimidine and purine 2′-deoxynucleosides of pharmaceutical interest as antiviral or antitumor compounds at short reaction times. Besides, increasing the biocatalyst amount 8 times per volume unit allowed obtaining a 5-fold improvement in floxuridine biosynthesis. The developed biocatalyst proved to be effective for the biosynthesis of a wide spectrum of halogenated nucleosides by employing an economical, simple and environmentally friendly methodology.