Two-step Enzymatic Synthesis of Guanine Arabinoside

The chemical synthesis of Guanine arabinoside (ara-G) is extremely complex, time-consuming, and seriously polluted. A two-step enzymatic synthesis process was developed to acquire ara-G easily. 2,6-Diaminopurine arabinoside (ara-DA) was first synthesized with purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase produced by Enterobacter aerogenes DGW-07. The conversion yield of ara-DA could reach above 90% when the reaction liquid contained 30 mmol·L−1 uracil arabinoside as arabinose donor, 10 mmol·L−1 2,6-diaminopurine as arabinose acceptor in pH 7.0 20 mmol·L−1 phosphate buffer, and reacted at 60°C for 48h. Then, ara-DA was effectively transformed into ara-G with adenylate deaminase produced by Aspergillus oryzae DAW-01. The total process had no complex separation and purification.