Polyribonucleotides containing thiopurines: synthesis and properties of poly(6-thioguanylic acid)

Abstract

The synthesis of poly(2-amino-6-chloropurinylic acid) [poly(n2cl6Pu)] by the polynucleotide phosphorylase catalyzed polymerization of 2-amino-6-chloro-9-(.beta.-D-ribofuranosyl)purine 5''-diphosphate and its chemical conversion to the antitumor agent poly(6-thioguanylic acid) [poly(s6G)] is described. Poly(s6G) formed a relatively unstable complex with poly(C), the properties of which were incompatible with those previously reported for the same complex prepared by another method. Poly(s6G) could be thermally converted to a copolymer of guanylic and 6-thioguanylic acids, the complex of which with poly(C) was strikingly similar to that reported earlier for poly(s6G) .cntdot. poly(C).