Synthesis of Selectively 15N-Labeled 2′-O-{[(Triisopropylsilyl)oxy]methyl}(=tom)-Protected Ribonucleoside Phosphoramidites and Their Incorporation into a Bistable 32Mer RNA Sequence

✍ Scribed by Philipp Wenter; Stefan Pitsch

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: German
• Weight: 288 KB
• Volume: 86
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200390330

✦ Synopsis

Abstract

We present optimized reaction conditions for the conversion of 2′‐O‐{[(triisopropylsilyl)oxy]methyl}(=tom) protected uridine and adenosine nucleosides into the corresponding protected (3‐^15^N)‐labeled uridine and cytidine and (1‐^15^N)‐labeled adenosine and guanosine nucleosides 4, 6, 12, and 18, respectively (Schemes 1–4). On a DNA synthesizer, the resulting ^15^N‐labeled 2′‐O‐tom‐protected phosphoramidite building blocks 19–22 were efficiently incorporated into five selected positions of a bistable 32mer RNA sequence 23 (known to adopt two different structures) (Fig. 1). By 2D‐HSQC and HNN‐COSY experiments in H~2~O/D~2~O 9 : 1, the ^15^N‐signals of all base‐paired ^15^N‐labeled nucleotides could be identified and attributed to one of the two coexisting structures of 23.