Nucléosides

2’-C-Methyl-5-methoxyuridine is a nucleoside analog that inhibits viral replication by inhibiting DNA synthesis. It is also used in the treatment of cancer, as it inhibits the growth of tumor cells by altering their genetic material. This drug is a phosphorothioate and can be activated with an activator to form its active form, which is incorporated into DNA during replication. 2’-C-Methyl-5-methoxyuridine has been shown to be effective against many viruses, including human immunodeficiency virus (HIV), herpes simplex virus type 1 (HSV1), and herpes simplex virus type 2 (HSV2). This drug has been shown to cause death of tumor cells via apoptosis or cell cycle arrest at the G0/G1 phase.

3’-b-C-Methyluridine (3′-b-CMU) is an analog of uridine. It inhibits the activity of viral and bacterial nucleases by attacking the phosphate group. 3′-b-CMU inhibits syncytial formation in cell cultures, which may be due to its ability to inhibit RNA synthesis. This drug has a hydroxyl group that can react with free radicals and may have some inhibitory effect on deoxyribonucleoside triphosphate hydrolysis. 3′-b-CMU is not widely used clinically because it is not readily available, but it is being reinvestigated for use in corynebacterium infections.

5-Methylcytidine is a nucleoside that is found in DNA and RNA. It is used in structural biology to probe the structure of DNA. 5-Methylcytidine binds to the enzyme methyl transferase, which catalyzes the transfer of a methyl group from S-adenosylmethionine to produce 5-methyluridine. This reaction occurs in long-term toxicity studies using primary cells, such as lymphocytes and fibroblasts. 5-Methylcytidine has been shown to inhibit tumour growth in mice by binding to nuclear dna polymerase and blocking transcription. The binding site for this drug on the polymerase is located at the same site as that for nucleoside analogues like azidothymidine (AZT) and zidovudine (AZT).