3413-66-9Relevant academic research and scientific papers
Prebiotic phosphorylation of 2-thiouridine provides either nucleotides or DNA building blocks via photoreduction
Xu, Jianfeng,Green, Nicholas J.,Gibard, Clémentine,Krishnamurthy, Ramanarayanan,Sutherland, John D.
, p. 457 - 462 (2019/04/08)
Breakthroughs in the study of the origin of life have demonstrated how some of the building blocks essential to biology could have been formed under various primordial scenarios, and could therefore have contributed to the chemical evolution of life. Missing building blocks are then sometimes inferred to be products of primitive biosynthesis, which can stretch the limits of plausibility. Here, we demonstrate the synthesis of 2′-deoxy-2-thiouridine, and subsequently 2′-deoxyadenosine and 2-deoxyribose, under prebiotic conditions. 2′-Deoxy-2-thiouridine is produced by photoreduction of 2,2′-anhydro-2-thiouridine, which is in turn formed by phosphorylation of 2-thiouridine—an intermediate of prebiotic RNA synthesis. 2′-Deoxy-2-thiouridine is an effective deoxyribosylating agent and may have functioned as such in either abiotic or proto-enzyme-catalysed pathways to DNA, as demonstrated by its conversion to 2′-deoxyadenosine by reaction with adenine, and 2-deoxyribose by hydrolysis. An alternative prebiotic phosphorylation of 2-thiouridine leads to the formation of its 5′-phosphate, showing that hypotheses in which 2-thiouridine was a key component of early RNA sequences are within the bounds of synthetic credibility.
Effect of base stacking on the acid-base properties of the adenine cation radical [A?+] in solution: ESR and DFT studies
Adhikary, Amitava,Kumar, Anil,Khanduri, Deepti,Sevilla, Michael D.
experimental part, p. 10282 - 10292 (2009/02/03)
In this study, the acid-base properties of the adenine cation radical are investigated by means of experiment and theory. Adenine cation radical (A?+) is produced by one-electron oxidation of dAdo and of the stacked DNA-oligomer (dA)6 by Cl2?- in aqueous glass (7.5 M LiCl in H2O and in D2O) and investigated by ESR spectroscopy. Theoretical calculations and deuterium substitution at C8-H and N6-H in dAdo aid in our assignments of structure. We find the pKa value of A?+ in this system to be ca. 8 at 150 K in seeming contradiction to the accepted value of ≤1 at ambient temperature. However, upon thermal annealing to ≥160 K, complete deprotonation of A?+ occurs in dAdo in these glassy systems even at pH ca. 3. A?+ found in (dA)6 at 150 K also deprotonates on thermal annealing. The stability of A?+ at 150 K in these systems is attributed to charge derealization between stacked bases. Theoretical calculations at various levels (DFT B3LYP/6-31G*, MPWB95, and HF-MP2) predict binding energies for the adenine stacked dimer cation radical of 12 to 16 kcal/mol. Further DFT B3LYP/6-31G* calculations predict that, in aqueous solution, monomeric A?+ should deprotonate spontaneously (a predicted pKa of ca. -0.3 for A?+). However, the charge resonance stabilized dimer AA?+ is predicted to result in a significant barrier to deprotonation and a calculated pK a of ca. 7 for the AA?+ dimer which is 7 pH units higher than the monomer. These theoretical and experimental results suggest that A?+ isolated in solution and A?+ in adenine stacks have highly differing acid-base properties resulting from the stabilization induced by hole derealization within adenine stacks.
Effective anomerisation of 2′-deoxyadenosine derivatives during disaccharide nucleoside synthesis
Gulyaeva, Irma V.,Neuvonen, Kari,Loennberg, Harri,Rodionov, Andrei A.,Shcheveleva, Elena V.,Bobkov, Georgii V.,Efimtseva, Ekaterina V.,Mikhailov, Sergey N.
, p. 1849 - 1864 (2007/10/03)
The formation of a disaccharide nucleoside (11) by O3′-glycosylation of 5′-O-protected 2′-deoxyadenosine or its N6-benzoylated derivative has been observed to be accompanied by anomerisation to the corresponding α-anomeric product (12). The latter reaction can be explained by instability of the N-glycosidic bond of purine 2′- deoxynucleosides in the presence of Lewis acids. An independent study on the anomerisation of partly blocked 2′-deoxyadenosine has been carried out. Additionally, transglycosylation has been utilized in the synthesis of 3′-O-β-D-ribofuranosyl-2′-deoxyadenosines and its α-anomer.
Ionization of purine nucleosides and nucleotides and their components by 193-nm laser photolysis in aqueous solution: Model studies for oxidative damage of DNA 1
Candeias,Steenken
, p. 699 - 704 (2007/10/02)
The effect of 20-ns pulses of 193-nm laser light on aqueous solutions of purine bases, (2′-deoxy)nucleosides, and (2′-deoxy)nucleotides was investigated, and monophotonic ionization was observed. Although (deoxy)ribose and (deoxy)ribose phosphates are also ionized by 193-nm light, the photoionization of the (deoxy)nucleosides and -tides takes place predominantly (90%) at the purine moiety, due to the much higher extinction coefficients at 193 nm of the bases as compared to the (deoxy)ribose phosphates. The quantum yields of photoionization (φPl) of the purines are in the range 0.01 to 0.08, based on φ(Cl-) at 193 nm of 0.46. As shown by comparison with data obtained from pulse radiolysis, the ionized purines, i.e., the radical cations, deprotonate in neutral solution, yielding neutral radicals. The radical cation of 1-methylguanosine, produced by photoionization in oxygen-saturated aqueous solution, deprotonates with the rate constant 3.5 × 105 s-1. In the absence of oxygen, the hydrated electrons resulting from the photoionization react with the untransformed purine derivatives to yield the corresponding radical anions. As these are rapidly protonated by water (as concluded from pulse radiolysis), the photoionization in deaerated neutral solution results in two different neutral radicals: a deprotonated radical cation and a protonated radical anion.
Improved procedure for the regiospecific synthesis of 2'-deoxyribonucleosides
Baud,Chavis,Lucas,Imbach
, p. 4437 - 4440 (2007/10/02)
2'-Deoxyribonucleosides are regiospecifically synthesized in high yields by catalyzing with KI-dibenzo-18-crown-6 PTC the condensation between unprotected silylated purines and pyrimidines and the appropriate easily available 2-deoxy-ribofuranosyl or pyranosyl sugar derivatives.
Synthesis and Cytotoxicity of Deoxyadenosine Analogues: Isomer Distribution in the Sodium Salt Glycosylation of 2,6-Disubstituted Purines
Kazimierczuk, Zygmunt,Vilpo, Juhani,Hildebrand, Catherine,Wright, George
, p. 1683 - 1687 (2007/10/02)
Several 2-substituted deoxyadenosine derivatives were synthesized and screened for cytotoxicity toward hematopoietic cells in culture.To prepare intermediates for these syntheses, the sodium salts of 2,6-dibromopurine and 2,6-bis(methylthio)purine were re
