Synthesis of analogs of 3'-phosphoadenosine 5'-phosphosulfate (PAPS)

Analogs of 3'-phosphoadenosine 5'-phosphosulfate, also known as PAPS, are useful in establishing sulfate transfer mechanisms in animals and may be produced by a chemical process yielding an analog B of a pure adenosine 2',3'-cyclic phosphate 5'-phosphate, which compound is initially prepared from the reaction of adenosine and pyrophosphoryl chloride. In the present process an analog B is selected from 8-bromoadenine, purine, hypoxanthine, 4-aminopyrrolo[2,3-d]pyrimidine (tubercidin), and 7-amino-pyrazolopyrimidine (formycin). In the pilot procedure the pure cyclic phosphate is reacted with triethylamine-N-sulfonic acid to produce 2',3'-cyclic phosphate 5'-phosphosulfate. Subsequently, by hydrolysis with the enzyme ribonuclease-T2, the desired compound, an analog of PAPS, is produced. Alternatively, the 2'-phosphoadenosine 5'-phosphosulfate, known as iso-PAPS, may be produced from 2',3'-cyclic phosphate 5'-phosphosulfate by treatment with a different enzyme, PDase II or spleen phosphodiesterase.