33422-70-7Relevant academic research and scientific papers
Stability studies on the newly discovered cyclic form of tRNA N 6-threonylcarbamoyladenosine (ct6A)
Matuszewski, Michal,Sochacka, Elzbieta
, p. 2703 - 2706 (2014)
A cyclic form of N6-threonylcarbamoyladenosine bearing an oxazolone moiety (ct6A) was discovered very recently at the position 37 in several tRNA sequences. Our study on the synthesized 5′,3′, 2′-O-acetylated derivative of ct6A confirmed high stability of the modified nucleoside under physiological conditions (PBS buffer, pH 7.4) and revealed remarkable stability of the oxazolone ring in acidic (100 mM HCl, pH 1) and basic (0.1 mM NaOH, pH 10) conditions. This feature may allow for the post-synthetic conversion of t6A into ct6A in assembled oligoribonucleotides.
Noncanonical RNA Nucleosides as Molecular Fossils of an Early Earth—Generation by Prebiotic Methylations and Carbamoylations
Schneider, Christina,Becker, Sidney,Okamura, Hidenori,Crisp, Antony,Amatov, Tynchtyk,Stadlmeier, Michael,Carell, Thomas
supporting information, p. 5943 - 5946 (2018/04/30)
The RNA-world hypothesis assumes that life on Earth started with small RNA molecules that catalyzed their own formation. Vital to this hypothesis is the need for prebiotic routes towards RNA. Contemporary RNA, however, is not only constructed from the four canonical nucleobases (A, C, G, and U), it also contains many chemically modified (noncanonical) bases. A still open question is whether these noncanonical bases were formed in parallel to the canonical bases (chemical origin) or later, when life demanded higher functional diversity (biological origin). Here we show that isocyanates in combination with sodium nitrite establish methylating and carbamoylating reactivity compatible with early Earth conditions. These reactions lead to the formation of methylated and amino acid modified nucleosides that are still extant. Our data provide a plausible scenario for the chemical origin of certain noncanonical bases, which suggests that they are fossils of an early Earth.
Synthesis and characterization of the native anticodon domain of E. coli tRNA(Lys): Simultaneous incorporation of modified nucleosides mnm5s2U, t6A, and pseudouridine using phosphoramidite chemistry
Sundaram, Mallikarjun,Crain, Pamela F.,Davis, Darrell R.
, p. 5609 - 5614 (2007/10/03)
The anticodon domain of E. coli tRNA(Lys) contains the hypermodified nucleosides mnm5s2U and t6A at positions 34 and 37, respectively, along with a more common ψ at position 39. The combination of these three nucleotides represents one of the most extensively modified RNA domains in nature. 2-Cyanoethyl diisopropylphosphoramidites of the hypermodified nucleosides mnm5s2U and t6A were each synthesized with protecting groups suitable for automated RNA oligonucleotide synthesis. The 17 nucleotide anticodon stem-loop of E. coli tRNA(Lys) was then assembled from these synthons using phosphoramidite coupling chemistry. Coupling efficiencies for the two hypermodified nucleosides and for pseudouridine phosphoramidite were all greater than 98%. A mild deprotection scheme was developed to accommodate the highly functionalized RNA. High coupling yields, mild deprotection, and efficient HPLC purification allowed us to obtain 1.8 mg of purified RNA from a 1 μmol scale RNA synthesis. Our efficient synthetic protocol will allow for biophysical investigation of this rather unique tRNA species wherein nucleoside modification has been shown to play a role in codon-anticodon recognition, tRNA aminoacyl synthetase recognition, and programmed ribosomal frameshifting. The human analogue, tRNA(Lys,3), is the specific tRNA primer for HIV-1 reverse transcriptase and has a similar modification pattern.
Nucleoside Annelating Reagents: N-(tert-Butyloxycarbonyl)-2-bromoacetamide and 2-Chloroketene Diethyl Acetal
Leonard, Nelson J.,Cruickshank, Kenneth A.
, p. 2480 - 2488 (2007/10/02)
The title reagents undergo cyclocondesation reaction with the amidine-like moiety of tri-O-acetyladenosine and cytidine (and related compounds) to form a new five-membered ring (etheno bridging), substituted with a (tert-butoxycarbonyl)amino or an ethoxy function.Some of the products exhibit useful fluorescence properties.Removal of the tert-butoxycarbonyl group with standard conditions gives the corresponding, somewhat unstable amino compounds which can be conveniently characterized as the corresponding N-acetyl derivatives.The reagents introducing additional substitution on the etheno bridge, with enhanced fluorescence, also suggest the possibility of cross-linking functionalization.
