UNIT 4.23 Synthesis of Oligoribonucleotides Containing N6-Alkyladenosine and 2-Methylthio-N6-Alkyladenosine

  1. Elzbieta Kierzek,
  2. Ryszard Kierzek

Published Online: 1 SEP 2004

DOI: 10.1002/0471142700.nc0423s17

Current Protocols in Nucleic Acid Chemistry

Current Protocols in Nucleic Acid Chemistry

How to Cite

Kierzek, E. and Kierzek, R. 2004. Synthesis of Oligoribonucleotides Containing N6-Alkyladenosine and 2-Methylthio-N6-Alkyladenosine. Current Protocols in Nucleic Acid Chemistry. 17:4.23:4.23.1–4.23.21.

Author Information

  1. Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland

Publication History

  1. Published Online: 1 SEP 2004
  2. Published Print: JUN 2004


The N6-alkyladenosines and 2-methylthio-N6-alkyladenosines are the most common modified adenosine nucleosides, and transfer ribonucleic acids (tRNA) are particularly rich in these modified nucleosides. They are present at position 37 of the anticodon arm, and the contributions of these hypermodified nucleosides to codon-anticodon interactions as well as to translation are significant, although they are not fully understood. This unit describes a new chemical synthesis method for oligoribonucleotides containing N6-alkyladenosines and 2-methylthio-N6-alkyladenosines via postsynthetic modifications of precursor oligoribonucleotides. To obtain oligoribonucleotides containing N6-alkyladenosines, a precursor oligoribonucleotide carrying 6-methylthiopurine riboside residues was used, whereas for the synthesis of oligoribonucleotides containing 2-methylthio-N6-alkyladenosines, a precursor oligoribonucleotide carrying the 2-methylthio-6-chloropurine riboside was applied. This allowed synthesis of modified oligoribonucleotides containing naturally occurring modified nucleosides such as N6-isopentenyladenosine (i6A), N6-methyladenosine (m6A), 2-methylthio-N6-isopentenyladenosine (ms2i6A), and 2-methylthio-N6-methyladenosine (ms2m6A), as well as several unnaturally modified adenosine derivatives.


  • N6-alkyladenosine;
  • 2-methylthio-N6-alkyladenosine;
  • phosphoramidites of modified nucleosides;
  • postsynthetic modification of oligoribonucleotides