Formation of pyrophosphate, tripolyphosphate, and phosphorylimidazole with the thioester, N, S-diacetylcysteamine, as the condensing agent

The formation of pyrophosphate, tripolyphosphate and phosphorylimidazole from orthophosphate in the presence of the thioester N, S-diacetylcysteamine is reported. Reactions performed with 0.20 M orthophosphate and 0.20 M N, S-diacetylcysteamine in 0.40 M imidazole under drying conditions at 50 C yielded pyrophosphate and tripolyphosphate after six days in the presence and absence of divalent metal ions. Reactions carried out at ambient temperature yielded phosphorylimidazole in the presence or absence of 0.05 M MgCl2, phosphorylimidazole and pyrophosphate in the presence of 0.05 M CaCl2, and pyrophosphate and tripolyphosphate in the presence of 0.15 M CaCl2. Such reactions represent potential pathways for the formation of energy-rich compounds providing free energy for use in prebiotic biopolymer synthesis.