Architecture of models for prebiotic synthesis of nucleic acids: template-directed synthesis of oligoguanylates using N-cyanoimidazole.

N-Cyanoimidazole is an efficient condensing agent for the polymerization of guanosine 5'-phosphate (pG) on a poly(C) template in an aqueous solution. At 0 degree C, up to about 30% of input pG was converted to a mixture of oligomers with a mean chain length of up to 7. The effect of divalent metal ions in the polymerization of pG on a poly(C) template was not so considerable as in that of oligo(A) on a poly(U) template. In the polymerization of pG, the moderate yields were obtaind in the presence of Co2+, Ni2+ and Cu2+.