Whole cells or isolated enzimes. different strategies to prepare modified nucleosides

MATÍAS NOBILE, ROSARIO MEDICI, MARISA TAVERNA PORRO, ESTEBAN GUDIÑO, LUIS IGLESIAS, ELIZABETH LEWKOWICZ, JAVIER MONTSERRAT, ADOLFO IRIBARREN

Berna

Congreso; International roundtable on nucleosides, nucleotides and nucleic acids; 2006

IS3N

Biotransformations offer advantages over traditional chemistry such as high regio- and stereoselectivity, mild experimental conditions and green technologies. In particular, chemoenzymatic routes are useful tools for the synthesis of nucleosides on laboratory as well as industrial scales. Ribo- and arabino- purine nucleosides are frequent targets in new synthetic developments because of their applications as antivirals and antitumorals. Two routes are being carried out in our lab to prepare these kinds of compounds by means of chemoenzymatic procedures. One of them starts from pentoses, like ribose or arabinose, and makes use of isolated enzymes such as lipases, phosphopentomutase and purine nucleoside phosphorylase, consecutively. In the other route, purine nucleosides are prepared through whole cell biocatalysed reactions, starting from cheaper pyrimidine nucleosides. In addition, biocatalysed deamination of the nucleosides prepared following the approaches above mentioned, generates the corresponding hydroxylated derivatives. The application of these strategies to the preparation of antivirals such as ribavirine and adenine and guanine arabinosides, will be discussed.