MODIFIED OLIGONUCLEOTIDE

摘要

A modified oligonucleotide comprising an oligonucleotide containing at its 3'end a modified nucleoside as a structural component, wherein the modified nucleoside is one having a carboxylic acid or steroid skeleton containing compound linked via a linker to the 3'end of nucleoside. The modified oligonucleotide can be produced by solid-phase synthesis using any of the unit compounds for solid-phase synthesis represented by the formula (XIA) or the unit compounds for solid-phase synthesis represented by the formula (XIS) as a starting material. (XIA) (XIS) wherein R<SUP>1</SUP>, R<SUP>2</SUP>, n, m, R<SUP>A</SUP> and R<SUP>S</SUP> are as defined in the description.