Enzymatic Synthesis of Nucleoside‐5′‐ O ‐(1‐thiophosphates) and ( S P )‐Adenosine‐5′‐ O ‐(1‐thiotriphosphate)

Treatment of adenosine with PSCl 3 in trimethyl phosphate gave, after ion‐exchange chromatography, adenosine‐5′‐ O ‐monophosphate (AMP; 28%) and adenosine‐5′‐ O ‐monothiophosphate (AMPS; 48%). AMPS was studied as a thiophosphate residue donor in an enzymatic transphosphorylation with nucleoside phosphotransferase (NPase) of the whole cells of Erwinia herbicola. As exemplified by a number of natural and sugar‐ and base‐modified nucleosides, it was demonstrated that NPase of the whole cells of Erwinia herbicola catalyzes the transfer of both thiophosphate and phosphate residues with a similar efficiency. An incubation of AMPS in a phosphorylating extract of Saccharomyces cerevisiae (K‐phosphate buffer (0.3  M , pH 7.0); 3% glucose; 15 m M MgCl 2 ; 28°, 8 h), followed by ion‐exchange column chromatography afforded AMP (8%), AMPS (recovered, 23%), ATP (11%), and ( S P )‐adenosine‐5′‐ O ‐(1‐thiotriphosphate) (( S P )‐ATP α S); (total yield 37%; 48% based on the consumed AMPS). For comparison of physicochemical properties, adenosine was chemically transformed into ATP α S as a mixture of the ( S P ) (53%) and (R P ) (44%) diastereoisomers.