EFFECTS OF 2'-O-(TRIFLUOROMETHYL)ADENOSINE ON OLIGODEOXYNUCLEOTIDE HYBRIDIZATION AND NUCLEASE STABILITY

The synthesis and properties of oligodeoxynucleotides (ODNs) containin g 2'-O-(trifluoromethyl)adenosine (2) are described, 2'-O-(Trifluorome thyl)adenosine (2) or N-6-(benzoyl)-2'-O-(trifluoromethyl)adeno (6) wa s obtained in 22 or 32% yield by treating tetraisopropyldisiloxane-1,3 -diyl)(TIPDS)adenosine (4) or N-6,N-6-(di-benzoyl)-2'-O-[(methylthio)t h io carbonyl]-3', 5'-O-(TIPDS)adenosine (5), respectively, with pyrid inium poly(hydrogen fluoride) in the presence of 1,3-dibromo-5,5-dimet hylhydantoin. Nucleoside 2 was incorporated into DNA hexadecamers, ODN s that contained 2 reduced the thermal stability of duplexes with thei r complementary DNAs but increased the thermal stability of duplexes w ith their complementary RNAs. Furthermore, ODNs containing 2 were slig htly more resistant to snake venom phosphodiesterase than an unmodifie d ODN.