The present invention provides iRNA agents comprising at least one subunit
of the formula (I):
##STR00001## wherein: A and B are each independently for each
occurrence O, N(R.sup.N) or S; X and Y are each independently for each
occurrence H, OH, a hydroxyl protecting group, a phosphate group, a
phosphodiester group, an activated phosphate group, an activated
phosphite group, a phosphoramidite, a solid support,
--P(Z')(Z'')O-nucleoside, --P(Z')(Z'')O-oligonucleotide, a lipid, a PEG,
a steroid, a lipophile, a polymer,
--P(Z')(Z'')O-Linker-OP(Z''')(Z'''')O-oligonucleotide, a nucleotide, an
oligonucleotide, --P(Z')(Z'')-formula (I), --P(Z')(Z'')-- or -Linker-R; R
is L.sup.G, -Linker-L.sup.G, or has the structure shown below:
##STR00002## L.sup.G is independently for each occurrence a
carbohydrate, e.g., monosaccharide, disaccharide, trisaccharide,
tetrasaccharide, oligosaccharide, polysaccharide; R.sup.N is
independently for each occurrence H, methyl, ethyl, propyl, isopropyl,
butyl, or benzyl; and Z', Z'', Z''' and Z'''' are each independently for
each occurrence O or S.
