Biomimetic Ketone Reduction by Disulfide Radical Anion
The conversion of ribonucleosides to 2′-deoxyribonucleosides is catalyzed by ribonucleoside reductase enzymes in nature. One of the key steps in this complex radical mechanism is the reduction of the 3′-ketodeoxynucleotide by a pair of cysteine residues, providing the electrons via a disulfide radic...
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doaj-f111bef165ba4ccda96674527606cf562021-09-26T00:45:37ZengMDPI AGMolecules1420-30492021-09-01265429542910.3390/molecules26185429Biomimetic Ketone Reduction by Disulfide Radical AnionSebastian Barata-Vallejo0Konrad Skotnicki1Carla Ferreri2Bronislaw Marciniak3Krzysztof Bobrowski4Chryssostomos Chatgilialoglu5Istituto per la Sintesi Organica e la Fotoreattività (ISOF), Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, ItalyInstitute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, PolandIstituto per la Sintesi Organica e la Fotoreattività (ISOF), Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, ItalyCenter for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614 Poznan, PolandInstitute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, PolandIstituto per la Sintesi Organica e la Fotoreattività (ISOF), Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, ItalyThe conversion of ribonucleosides to 2′-deoxyribonucleosides is catalyzed by ribonucleoside reductase enzymes in nature. One of the key steps in this complex radical mechanism is the reduction of the 3′-ketodeoxynucleotide by a pair of cysteine residues, providing the electrons via a disulfide radical anion (RSSR<sup>•−</sup>) in the active site of the enzyme. In the present study, the bioinspired conversion of ketones to corresponding alcohols was achieved by the intermediacy of disulfide radical anion of cysteine (CysSSCys)<sup>•−</sup> in water. High concentration of cysteine and pH 10.6 are necessary for high-yielding reactions. The photoinitiated radical chain reaction includes the one-electron reduction of carbonyl moiety by disulfide radical anion, protonation of the resulting ketyl radical anion by water, and H-atom abstraction from CysSH. The (CysSSCys)<sup>•−</sup> transient species generated by ionizing radiation in aqueous solutions allowed the measurement of kinetic data with ketones by pulse radiolysis. By measuring the rate of the decay of (CysSSCys)<sup>•−</sup> at λ<sub>max</sub> = 420 nm at various concentrations of ketones, we found the rate constants of three cyclic ketones to be in the range of 10<sup>4</sup>–10<sup>5</sup> M<sup>−1</sup>s<sup>−1</sup> at ~22 °C.https://www.mdpi.com/1420-3049/26/18/5429biomimetic chemistrycysteineketone reductionfree radicalspulse radiolysiskinetics |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Sebastian Barata-Vallejo Konrad Skotnicki Carla Ferreri Bronislaw Marciniak Krzysztof Bobrowski Chryssostomos Chatgilialoglu |
spellingShingle |
Sebastian Barata-Vallejo Konrad Skotnicki Carla Ferreri Bronislaw Marciniak Krzysztof Bobrowski Chryssostomos Chatgilialoglu Biomimetic Ketone Reduction by Disulfide Radical Anion Molecules biomimetic chemistry cysteine ketone reduction free radicals pulse radiolysis kinetics |
author_facet |
Sebastian Barata-Vallejo Konrad Skotnicki Carla Ferreri Bronislaw Marciniak Krzysztof Bobrowski Chryssostomos Chatgilialoglu |
author_sort |
Sebastian Barata-Vallejo |
title |
Biomimetic Ketone Reduction by Disulfide Radical Anion |
title_short |
Biomimetic Ketone Reduction by Disulfide Radical Anion |
title_full |
Biomimetic Ketone Reduction by Disulfide Radical Anion |
title_fullStr |
Biomimetic Ketone Reduction by Disulfide Radical Anion |
title_full_unstemmed |
Biomimetic Ketone Reduction by Disulfide Radical Anion |
title_sort |
biomimetic ketone reduction by disulfide radical anion |
publisher |
MDPI AG |
series |
Molecules |
issn |
1420-3049 |
publishDate |
2021-09-01 |
description |
The conversion of ribonucleosides to 2′-deoxyribonucleosides is catalyzed by ribonucleoside reductase enzymes in nature. One of the key steps in this complex radical mechanism is the reduction of the 3′-ketodeoxynucleotide by a pair of cysteine residues, providing the electrons via a disulfide radical anion (RSSR<sup>•−</sup>) in the active site of the enzyme. In the present study, the bioinspired conversion of ketones to corresponding alcohols was achieved by the intermediacy of disulfide radical anion of cysteine (CysSSCys)<sup>•−</sup> in water. High concentration of cysteine and pH 10.6 are necessary for high-yielding reactions. The photoinitiated radical chain reaction includes the one-electron reduction of carbonyl moiety by disulfide radical anion, protonation of the resulting ketyl radical anion by water, and H-atom abstraction from CysSH. The (CysSSCys)<sup>•−</sup> transient species generated by ionizing radiation in aqueous solutions allowed the measurement of kinetic data with ketones by pulse radiolysis. By measuring the rate of the decay of (CysSSCys)<sup>•−</sup> at λ<sub>max</sub> = 420 nm at various concentrations of ketones, we found the rate constants of three cyclic ketones to be in the range of 10<sup>4</sup>–10<sup>5</sup> M<sup>−1</sup>s<sup>−1</sup> at ~22 °C. |
topic |
biomimetic chemistry cysteine ketone reduction free radicals pulse radiolysis kinetics |
url |
https://www.mdpi.com/1420-3049/26/18/5429 |
work_keys_str_mv |
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1716869900015763456 |