Bertram, Lauren;
Roberts, Samuel J;
Powner, Matthew W;
Szabla, Rafał;
(2022)
Photochemistry of 2-thiooxazole: a plausible prebiotic precursor to RNA nucleotides.
Physical Chemistry Chemical Physics
10.1039/d2cp03167a.
(In press).
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Abstract
Potentially prebiotic chemical reactions leading to RNA nucleotides involve periods of UV irradiation, which are necessary to promote selectivity and destroy biologially irrelevant side products. Nevertheless, UV light has only been applied to promote specific stages of prebiotic reactions and its effect on complete prebiotic reaction sequences has not been extensively studied. Here, we report on an experimental and computational investigation of the photostability of 2-thiooxazole (2-TO), a potential precursor of pyrimidine and 8-oxopurine nucleotides on early Earth. Our UV-irradiation experiments resulted in rapid decomposition of 2-TO into unidentified small molecule photoproducts. We further clarify the underlying photochemistry by means of accurate ab initio calculations and surface hopping molecular dynamics simulations. Overall, the computational results show efficient rupture of the aromatic ring upon the photoexcitation of 2-TO via breaking of the C-O bond. Consequently, the initial stage of the divergent prebiotic synthesis of pyrimidine and 8-oxopurine nucleotides would require periodic shielding from UV light either with sun screening chromophores or through a planetary scenario that would protect 2-TO until it is transformed into a more stable intermediate compound, e.g. oxazolidinone thione.
Type: | Article |
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Title: | Photochemistry of 2-thiooxazole: a plausible prebiotic precursor to RNA nucleotides |
Location: | England |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1039/d2cp03167a |
Publisher version: | https://doi.org/10.1039/D2CP03167A |
Language: | English |
Additional information: | This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. |
UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
URI: | https://discovery.ucl.ac.uk/id/eprint/10155253 |
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