Synthesis and hybridization properties of 2′-O-methylated oligoribonucleotides incorporating 2′-O-naphthyluridines

Abstract

2′-O-(1-Naphthyl)uridine and 2′-O-(2-naphthyl)uridine were synthesized by a microwave-mediated reaction of 2,2′-anhydrouridine with naphthols. Using the 3′-phosphoramidite building blocks, these 2′-O-aryluridine derivatives were incorporated into 2′-O-methylated oligoribonucleotides. Incorporation of five 2′-O-(2-naphthyl)uridines into a 2′-O-methylated RNA sense strand significantly increased the thermostability of the duplex with a 2′-O-methylated RNA antisense strand. Circular dichroism spectroscopy and molecular dynamic simulation of the duplexes formed between the modified RNAs and 2′-O-methyl RNAs suggested that there are π–π interactions between two neighboring naphthyl groups in a sequence of the five consecutively modified nucleosides.