15763-06-1Relevant articles and documents
Intramolecular Stacking Association of Three Dinucleoside Monophosphates Containing Naturally-occurring 1-Methyladenosine Residue(s): m1ApA. Apm1A, m1Apm1A
Takeuchi, Yasuhiro,Tazawa, Ichiro,Inoue, Yasuo
, p. 3598 - 3602 (1982)
Three modified dinucleoside monophosphates containing naturally-occurring 1-methyladenosine residue, m1ApA, Apm1A, and m1Apm1A, were prepared.Intramolecular stacking association properties of these dimers were studied quantitatively using two independent methods.Thermal denaturation and acid-base titration experiments reached to the same conclusion that both m1pA and Apm1 were less stacked than ApA.Acid-base titration experiment also showed that the three modified dimers, in their neutral forms, were stacked to almost the same extent as ApA.These results indicate the N-1 methylation of an adenine base does not enhance stacking interaction of dimers, in sharp contrast to the N6 methylation of the same base.UV hypochromicity and CD measurements were also made for the three dimers, and the results were found to be consistent with those of th estacking quotient determination.
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.
Methylation of Adenosine and Related Nucleosides with Trimethylselenonium Hydroxyde, and Regiospecific Effects of Copper(II) Ions
Yamauchi, Kiyoshi,Hattori, Kazue,Kinoshita, Masayoshi
, p. 1327 - 1330 (2007/10/02)
Methylation of adenosine, deoxyadenosine, 6-N-methyladenosine and 2'(3')-O-methyladenosines with trimethylselenonium hydroxyde was studied in the presence and absence of copper(II) acetylacetonate .It was found that copper(II) ions promoted methylation of the 2'(3')-OH groups of the ribonucleosides but suppressed methylation at the N-1 position of the adenine rings.The metal-ion effects are discussed in conjunction with a catalytic role for Cu(AA)2 in the reactions.
