62475-47-2Relevant articles and documents
Prebiotic Photochemical Coproduction of Purine Ribo- And Deoxyribonucleosides
Xu, Jianfeng,Green, Nicholas J.,Russell, David A.,Liu, Ziwei,Sutherland, John D.
supporting information, p. 14482 - 14486 (2021/09/18)
The hypothesis that life on Earth may have started with a heterogeneous nucleic acid genetic system including both RNA and DNA has attracted broad interest. The recent finding that two RNA subunits (cytidine, C, and uridine, U) and two DNA subunits (deoxyadenosine, dA, and deoxyinosine, dI) can be coproduced in the same reaction network, compatible with a consistent geological scenario, supports this theory. However, a prebiotically plausible synthesis of the missing units (purine ribonucleosides and pyrimidine deoxyribonucleosides) in a unified reaction network remains elusive. Herein, we disclose a strictly stereoselective and furanosyl-selective synthesis of purine ribonucleosides (adenosine, A, and inosine, I) and purine deoxynucleosides (dA and dI), alongside one another, via a key photochemical reaction of thioanhydroadenosine with sulfite in alkaline solution (pH 8-10). Mechanistic studies suggest an unexpected recombination of sulfite and nucleoside alkyl radicals underpins the formation of the ribo C2′-O bond. The coproduction of A, I, dA, and dI from a common intermediate, and under conditions likely to have prevailed in at least some primordial locales, is suggestive of the potential coexistence of RNA and DNA building blocks at the dawn of life.
Selective Generation and Reactivity of 5′-Adenosinyl and 2′-Adenosinyl Radicals
Chatgilialoglu, Chryssostomos,Duca, Maria,Ferreri, Carla,Guerra, Maurizio,Ioele, Marcella,Mulazzani, Quinto G.,Strittmatter, Harald,Giese, Bernd
, p. 1249 - 1255 (2007/10/03)
The reaction of hydrated electrons (eaq-) with 8-bromoadenosine 7 has been investigated by radiolytic methods coupled with product studies. Pulse radiolysis revealed that one-electror reductive cleavage of the C-Br bond gives the C8 radical 8 followed by a fast radical translocation to the sugar moiety. The reaction is partitioned between C5′ and C2′ positions in a 60:40 ratio leading to 5′-adenosinyl radical 9 and 2′-adenosinyl radical 11. This radical translocation from C8 to different sites of the sugar moiety has also been addressed computationally by means of DFT B3LYP calculations. In addition, ketone 21 was prepared and photolyzed providing an independent generation of C2′ radical 11. Both C5′ and C2′ radicals undergo unimolecular reactions. Radical 9 attacks adenine with a rate constant of 1.0 × 104 s-1 and gives the aromatic aminyl radical 10, whereas C2′ radical 11 liberates adenine with a rate constant of 1.1 × 105 s-1.
