- A prebiotically plausible synthesis of pyrimidine β-ribonucleosides and their phosphate derivatives involving photoanomerization
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Previous research has identified ribose aminooxazoline as a potential intermediate in the prebiotic synthesis of the pyrimidine nucleotides with remarkable properties. It crystallizes spontaneously from reaction mixtures, with an enhanced enantiomeric excess if initially enantioenriched, which suggests that reservoirs of this compound might have accumulated on the early Earth in an optically pure form. Ribose aminooxazoline can be converted efficiently into α-ribocytidine by way of 2,2'-anhydroribocytidine, although anomerization to β-ribocytidine by ultraviolet irradiation is extremely inefficient. Our previous work demonstrated the synthesis of pyrimidine β-ribonucleotides, but at the cost of ignoring ribose aminooxazoline, using arabinose aminooxazoline instead. Here we describe a long-sought route through ribose aminooxazoline to the pyrimidine β-ribonucleosides and their phosphate derivatives that involves an extraordinarily efficient photoanomerization of α-2-thioribocytidine. In addition to the canonical nucleosides, our synthesis accesses β-2-thioribouridine, a modified nucleoside found in transfer RNA that enables both faster and more-accurate nucleic acid template-copying chemistry.
- Xu, Jianfeng,Tsanakopoulou, Maria,Magnani, Christopher J.,Szabla, Rafa?,?poner, Judit E.,?poner, Ji?í,Góra, Robert W.,Sutherland, John D.
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p. 303 - 309
(2017/04/03)
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- Chiral Nanozymes-Gold Nanoparticle-Based Transphosphorylation Catalysts Capable of Enantiomeric Discrimination
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Enantioselectivity in RNA cleavage by a synthetic metalloenzyme has been demonstrated for the first time. Thiols containing chiral ZnII-binding head groups have been self-assembled on the surface of gold nanoparticles. This results in the spontaneous formation of chiral bimetallic catalytic sites that display different activities (kcat) towards the enantiomers of an RNA model substrate. Substrate selectivity is observed when the nanozyme is applied to the cleavage of the dinucleotides UpU, GpG, ApA, and CpC, and remarkable differences in reactivity are observed for the cleavage of the enantiomerically pure dinucleotide UpU.
- Chen, Jack L.-Y.,Pezzato, Cristian,Scrimin, Paolo,Prins, Leonard J.
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supporting information
p. 7028 - 7032
(2016/05/19)
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- Ribonuclease activity of an artificial catalyst that combines a ligated CuII ion and a guanidinium group at the upper rim of a cone -Calix[4]arene platform
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A cone-calix[4]arene derivative, featuring a guanidinium group and a CuII ion ligated to a 1,4,7-triazacyclononane (TACN) ligand at the 1,3-distal positions of the upper rim, effectively catalyzes the cleavage of 2-hydroxypropyl p-nitrophenyl phosphate (HPNP) and a number of diribonucleoside 3′,5′-monophosphates (NpN′). Kinetic and potentiometric measurements support the operation of a general-base/general-acid mechanism and demonstrate that the hydroxo form of the ligated CuII ion is the sole catalytically active species. Rate enhancements relative to the background hydrolysis reaction at 1 mM catalyst concentration are 6 × 105-fold for HPNP and cluster around 107-fold with the most favorable catalyst-NpN′ combinations.
- Salvio, Riccardo,Volpi, Stefano,Cacciapaglia, Roberta,Casnati, Alessandro,Mandolini, Luigi,Sansone, Francesco
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p. 5887 - 5893
(2015/06/16)
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- Diguanidinocalix[4]arenes as effective and selective catalysts of the cleavage of diribonucleoside monophosphates
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Calix[4]arenes derivatives 1 and 2, featuring two guanidine units at the upper rim, catalyze the transesterification of diribonucleoside monophosphates much more effectively than that of HPNP. Rate accelerations relative to the background range from 10su
- Salvio, Riccardo,Cacciapaglia, Roberta,Mandolini, Luigi,Sansone, Francesco,Casnati, Alessandro
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p. 34412 - 34416
(2014/11/12)
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