| abstract |
Compounds of formula I; <IMAGE> I wherein R1 is hydrogen, or a blocking group that is compatible with oligonucleotide synthesis; R2 is hydrogen, nitro, lower alkyl amino, diloweralkyl amino or methyl; R3 is hydrogen or -P(R4)OR5; R4 is chlorine, 4-nitroimidazole, imidazole, tetrazole, triazole or di(lower-alkyl)amino-; R5 is methyl, 2-cyanoethyl or 2,2,2-trichloroethyl; n is from 0 to 2 X is oxygen, sulfur, or -NR6; R6 is hydrogen or lower alkyl; Q is chosen from the group consisting of <IMAGE> and <IMAGE> R7 is lower-alkyl or loweralkyloxy methylene; and R8 is hydrogen, benzoyl, anisoyl, or lower-alkyl carbonyl and its pharmaceutically acceptable addition salts are nucleotide analogs. Modified oligonucleotides containing the nucleoside analogs of formula I are stable to nuclease degradation and are useful in inhibiting gene expression, in sequencing, and in mutagenesis. |