Theoretical Studies on the Photochemistry of Pentose Aminooxazoline, a Hypothetical Intermediate Product in the Prebiotic Synthetic Scenario of RNA Nucleotides

• Published in: The journal of physical chemistry. B Vol. 120; no. 35; pp. 9329 - 9337
• Main Authors: Ai, Yuejie, Xia, Shuhua, Liao, Rong-Zhen
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 08.09.2016
• Subjects: Channels; Density functional theory; Fluid dynamics; Nucleotides; Oxazoles - chemistry; Oxazoles - radiation effects; Pentose; Pentoses - chemistry; Pentoses - radiation effects; Photochemical Processes; Photochemistry; Prebiotics; Precursors; Quantum Theory; Ribonucleic acids; RNA - chemistry; Water - chemistry
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/acs.jpcb.6b06061

2-Aminooxazole is generally considered a prebiotic precursor of ribonucleotides on the early earth. Its pentose compound, pentose aminooxazoline, has been suggested to be a key intermediate in the prebiotic synthetic scenario. In this article, detailed mechanism of the photochemistry of pentose aminooxazoline has been studied by performing density functional theory and multireference complete active space self-consistent field calculations. Parallel to the “ring-puckering” process, which leads to ultrafast nonradiative deactivation, several other photodissociation channels are explored in detail. In addition, the influences of the pentose structure and solvation effects with both implicit and explicit water models have been uncovered for both neutral and protonated forms. The current theoretical results provide very important information not only for the photostability of RNA nucleotides but also for an in-depth understanding of the synthesis of other prebiotic nucleotides.