Synthesis of enzymatically active D-7,8-dihydroneopterin-3'-triphosphate

The first chemical synthesis of D-neopterin-3'-triphosphate and D-7,8-dihydroneopterin-3'-triphosphate is described. D-neopterin-3'-monophosphate was first 1'-2'-0-formylated with anhydrous formic acid, then activated with 1,1'-carbonyldiimidazole and phosphorylated with n-tributyl-ammonium pyrophosphate. The yield of 3'-NTP was 24%. D-7,8-dihydroneopterin-3'-triphosphate was obtained by chemical (hyposulfite) or catalytic (Pd:H2) reduction of 3'-NTP. Preparations from both reductions were fully active in two different enzymatic systems: synthesis of L-5,6,7,8-tetrahydrobiopterin and in the C-2'-epimerization reaction to L-7,8-dihydromonapterin-3'-triphosphate.