A novel linker for the solid-phase synthesis of a library of 3′-thiophosphorylated dinucleotides

Solid-phase supports for oligonucleotide synthesis

This unit attempts to provide a reasonably complete inventory of over 280 solid supports available to oligonucleotide chemists for preparation of natural and 3'-modified oligonucleotides. Emphasis is placed on non-nucleosidic solid supports. The relationship between the structural features of linkers and their behavior in oligonucleotide synthesis and deprotection is discussed wherever the relevant observations are available.

Solid phase synthesis of nucleobase and ribose modified inosine nucleoside analogues

The synthesis and the use of new N-1-dinitrophenyl-inosine based solid support is reported. The support, which binds the nucleoside by a 5'-O-monomethoxytrityl function, reacting with N-nucleophiles allowed the synthesis of a small library of N-1 alkylated inosine and AICAR derivatives. Moreover, the obtained supports, after the cleavage of the 2' -3' ribose bond, furnished a set of new N-1 alkylated-2' -3' -secoinosine derivatives in high yields.

Phosphorothioate di- and trinucleotides as a novel class of anti-hepatitis B virus agents

Several nucleoside analogs are under clinical development for use against hepatitis B virus (HBV). Lamivudine (3TC), a nucleoside analog, and adefovir dipivoxil (ADV), an acyclonucleotide analog, are clinically approved. However, long-term treatment can induce viral resistance, and following the cessation of therapy, viral rebound is frequently observed. There continues to be a need for new antiviral agents with novel mechanisms of action. A library of more than 600 di- and trinucleotide compounds synthesized by parallel synthesis using a combinatorial strategy was screened for potential inhibitors of HBV replication using the chronically HBV-producing cell line 2.2.15. Through an iterative process of synthesis, lead optimization, and screening, three analogs were identified as potent inhibitors of HBV replication: dinucleotides ORI-7246 (drug concentration at which a 10-fold reduction of HBV DNA was observed [EC(90)], 1.4 microM) and ORI-9020 (EC(90), 1.2 microM) and trinucleotide ORI-7170 (EC(90), 7.2 microM). These analogs inhibited the replication of both strands of HBV DNA. No suppression of HBV protein synthesis or intracellular core particle formation by these analogs was observed. No inhibition of HBV DNA strand elongation by the analogs or their 5'-triphosphate versions was apparent in in vitro polymerase assays. Although the exact mechanism of action is not yet identified, present data are consistent with an inhibition of the HBV reverse transcriptase-directed priming step prior to elongation of the first viral DNA strand. In transient-transfection assays, these analogs inhibited the replication of 3TC-resistant HBV. Synergistic interactions in combination treatments between the analogs and either 3TC or ADV were observed. These compounds represent a novel class of anti-HBV molecules and warrant further investigation as potential therapeutic agents.