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A Plausible Mechanism of Uracil Photohydration Involves an Unusual Intermediate

Park, Woojin and Filatov (Gulak), Michael and Sadiq, Saima and Gerasimov, Igor and Lee, Seunghoon and Joo, Taiha and Choi, Cheol Ho (2022) A Plausible Mechanism of Uracil Photohydration Involves an Unusual Intermediate. Journal of Physical Chemistry Letters, 13 (30). pp. 7072-7080. ISSN 1948-7185. PMCID PMC9358713. doi:10.1021/acs.jpclett.2c01694.

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It is well-known that photolysis of pyrimidine nucleobases, such as uracil, in an aqueous environment results in the formation of hydrate as one of the main products. Although several hypotheses regarding photohydration have been proposed in the past, e.g., the zwitterionic and “hot” ground-state mechanisms, its detailed mechanism remains elusive. Here, theoretical nonadiabatic simulations of the uracil photodynamics reveal the formation of a highly energetic but kinetically stable intermediate that features a half-chair puckered pyrimidine ring and a strongly twisted intracyclic double bond. The existence and the kinetic stability of the intermediate are confirmed by a variety of computational chemistry methods. According to the simulations, the unusual intermediate is mainly formed almost immediately (∼50–200 fs) upon photoabsorption and survives long enough to engage in a hydration reaction with a neighboring water. A plausible mechanism of uracil photohydration is proposed on the basis of the modeling of nucleophilic insertion of water into the twisted double bond of the intermediate.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle
Filatov (Gulak), Michael0000-0002-1541-739X
Sadiq, Saima0000-0002-0711-4946
Gerasimov, Igor0000-0001-7762-2594
Lee, Seunghoon0000-0003-3665-587X
Joo, Taiha0000-0003-2690-7789
Choi, Cheol Ho0000-0002-8757-1396
Additional Information:© 2022 The Authors. Published by American Chemical Society. Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0). Received 4 June 2022. Accepted 11 July 2022. Published online 28 July 2022. The support by Samsung Science and Technology Foundations Grant SSTF-BA1701-12 and Grants 2020R1A2C2008246 and 2020R1A5A1019141 funded by the Ministry of Science and ICT is acknowledged. This work was also supported by the Korea Polar Research Institute (KOPRI, PE21120). The authors declare no competing financial interest.
Funding AgencyGrant Number
Samsung Science and Technology FoundationSSTF-BA1701-12
National Research Foundation of Korea2020R1A2C2008246
National Research Foundation of Korea2020R1A5A1019141
Korea Polar Research InstitutePE21120
Subject Keywords:Energy, Hydration, Mathematical methods, Pyrimidine, Uracil
Issue or Number:30
PubMed Central ID:PMC9358713
Record Number:CaltechAUTHORS:20220729-722028000
Persistent URL:
Official Citation:A Plausible Mechanism of Uracil Photohydration Involves an Unusual Intermediate. Woojin Park, Michael Filatov (Gulak), Saima Sadiq, Igor Gerasimov, Seunghoon Lee, Taiha Joo, and Cheol Ho Choi. The Journal of Physical Chemistry Letters 2022 13 (30), 7072-7080; DOI: 10.1021/acs.jpclett.2c01694
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:115961
Deposited By: George Porter
Deposited On:01 Aug 2022 18:18
Last Modified:17 Aug 2022 16:47

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