Our laboratories analyze the synthetic reactions leading from formamide NH2COH to prebiotically relevant compounds in the presence of catalysts. We have described the formation of all the biological nucleic bases, of carboxylic acids, of two aminoacids and of condensing agents in the presence of catalysts of terrestrial origin (Saladino et al., 2012) and of one meteorite.

Heat-dependent synthetic reactions from NH2COH lead to the synthesis of acyclonucleosides, not (yet?) to that of nucleosides [hurdle # 1]. Nucleosides are phosphorylated in the presence of NH2COH and a phosphate source, yielding also cyclic nucleotides (Costanzo et al., 2007). 3’,5’cyclic GMP non-enzymatically polymerizes up to at least 25mers, as shown by PAGE, MALDI ToF, 31P-NMR, specific RNAse and inhibitors analyses (Costanzo et al., 2012).The reaction is stimulated by 1,8-diazabicycloundec-7-ene and by dimethylformamide. 3’,5’cUMP does not polymerize spontaneously [hurdle # 2], 3’,5’cAMP polymerizes very poorly [hurdle # 3]. We will discuss data on the polymerization of 3’,5’cCMP and on a ribozyme activity exerted by oligomers neo-synthesized from cyclic nucleotides. This approach finds its larger perspective in the evolutionary scenario depicted by Edward Trifonov (2009).

References

Saladino, R., Botta, G., Pino, S., Costanzo, G., Di Mauro, E. (2012) Genetics first or metabolism first? The formamide clue. Chem.Soc.Rev. 41, 5526–5565.

Costanzo G., R. Saladino, C. Crestini, F. Ciciriello, E. Di Mauro (2007) Nucleoside phosphorylation by phosphate minerals, J. Biol. Chem. 282, 16729-16735.

Costanzo, G., Saladino, R., Botta, G., Giorgi, A., Scipioni, A., Pino, S., Di Mauro, E. (2012) Generation of RNA molecules by base catalyzed click-like reaction. ChemBioChem 13, 999-1008.

Trifonov, E.N. (2009) Origin of the genetic code and of the earliest oligopeptides Res. Microbiol. 160, 481-486.