ABSTRACT
Novel oligonucleotide analogs that bear phosphodiester and bioreversible S-pivaloyl 2-mercaptoethyl (SPME) phosphate triester internucleosidic linkages are described. Their synthesis employs a novel methodology of oligonucleotide deprotection under mild, non-aqueous conditions.
Subject(s)
Oligonucleotides, Antisense/chemical synthesis , Organophosphates/chemical synthesis , Organophosphates/chemistry , Organophosphorus Compounds/chemical synthesis , Organophosphorus Compounds/chemistry , Organothiophosphorus Compounds/chemistry , Pentanoic Acids/chemistryABSTRACT
The synthesis of 7-propynyl-, 7-iodo- and 7-cyano-7-deaza-2-amino-2'-deoxyadenosines is described. The nucleosides were synthesized, functionalized into the phosphoramidites and incorporated into oligodeoxynucleotides. Spectroscopic melting experiments against complementary RNA showed increases of 3-4 degreesC per modification for single substitutions and smaller increases per incorporation for multiple substitutions relative to unmodified control sequences. The 7-propyne and 7-iodo nucleosides were incorporated into antisense sequences targeting the 3'-UTR of murine C- raf mRNA. Both nucleosides demonstrated substitution-dependent potency. The sequences with three and four substitutions of the 7-propyne-7-deaza-2-amino-2'-deoxyadenosine exhibited a 2-3-fold increase in potency over unmodifed controls.
Subject(s)
Deoxyadenosines/chemistry , Oligonucleotides, Antisense/pharmacology , Animals , Base Sequence , Cell Line , Hydrogen Bonding , Magnetic Resonance Spectroscopy , Mice , Molecular Structure , Oligonucleotides, Antisense/chemistryABSTRACT
A novel solid-phase synthesis of 5'-radiolabeled oligonucleotides is described. The labeling reaction is carried out by the phosphoramidite method with the aid of [4,6-di-14C]-5'-dimethoxytritylthymidine building block 1. The feasibility of the method is demonstrated by preparation of 3'-phosphorylated dodecathymidylate phosphorothioate containing radiolabeled nucleoside at the 5'-terminus.
