Spontaneous Prebiotic Formation of a β-Ribofuranoside That Self-Assembles with a Complementary Heterocycle


Abstract Image

The RNA World hypothesis is central to many current theories regarding the origin and early evolution of life. However, the formation of RNA by plausible prebiotic reactions remains problematic. Formidable challenges include glycosidic bond formation between ribose and the canonical nucleobases, as well as the inability of nucleosides to mutually select their pairing partners from a complex mixture of other molecules prior to polymerization. Here we report a one-pot model prebiotic reaction between a pyrimidine nucleobase (2,4,6-triaminopyrimidine, TAP) and ribose, which produces TAP-ribose conjugates in high yield (60–90%). When cyanuric acid (CA), a plausible ancestral nucleobase, is mixed with a crude TAP+ribose reaction mixture, micrometer-length supramolecular, noncovalent assemblies are formed. A major product of the TAP+ribose reaction is a β-ribofuranoside of TAP, which we term TARC. This nucleoside is also shown to efficiently form supramolecular assemblies in water by pairing and stacking with CA. These results provide a proof-of-concept system demonstrating that several challenges associated with the prebiotic emergence of RNA, or pre-RNA polymers, may not be as problematic as widely believed.


Supporting Information

Additional characterization of the formation of TARC is given in Figures S1–S7 and S12, detailed NMR characterization of TARC is given in Figures S8–S10, a proposed reaction mechanism for the formation of TARC from TAP and ribose is presented in Figure S11. Additional CD characterization of TARC assemblies is given in Figures S13–S14. This material is available free of charge via the Internet at http://pubs.acs.org.

Spontaneous Prebiotic Formation of a β‑Ribofuranoside That Self-Assembles with a Complementary Heterocycle

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Link collected : https://pubs.acs.org/doi/10.1021/ja410124v#