Synthetic substances known as nucleoside analogues imitate the structure of naturally occurring nucleosides, which are the building blocks of DNA and RNA. Because these analogues can disrupt the synthesis of nucleic acids in infections or cancer cells, they are employed in medicine as antiviral and anticancer medicines. An overview of nucleoside analogues is provided below: Analogs of nucleosides have a structure with natural nucleosides, consisting of a sugar molecule connected to a nitrogenous base. They are different, nevertheless, in one crucial way: they include modified sugars or bases. They are able to interfere with target cells' DNA or RNA's regular function because to this modification.Azidothymidine (AZT), a nucleoside analogue used to treat HIV/AIDS, is among the most well-known instances. Similar to thymidine, a naturally occurring DNA nucleoside, AZT has an azido group (-N3) at the 3' carbon of the sugar moiety rather than the typical hydroxyl (-OH) group. The azido group in AZT inhibits further elongation of the DNA chain when HIV-infected cells incorporate it into their DNA during replication, hence preventing viral replication. Cytarabine, often known as ara-C, is a significant nucleoside analogue that is used to treat different types of leukemia. Similar to cytidine in nature, cytarabine also contains an arabinose sugar rather than ribose. Its ability to alter its structure renders it a potent suppressor of DNA synthesis, especially in cancer cells that divide quickly.Acyclovir is a nucleoside analogue used in the field of antiviral medications for the treatment of herpes virus infections. Acyclovir is similar to the nucleoside guanosine, but instead of a ribose sugar, it possesses an acyclic side chain. Viral DNA synthesis is stopped when it specifically targets viral DNA polymerase after becoming phosphorylated within infected cells. The capacity of nucleoside analogues to specifically target enzymes involved in nucleic acid replication accounts for their versatility. They can stop the spread of viruses or the growth of cancer cells by interfering with these mechanisms. However, there may be adverse consequences associated with their use, including gastrointestinal problems or suppression of the bone marrow.To sum up, nucleoside analogs are a potent class of drugs with a wide range of uses in virology and oncology. They are useful weapons in the battle against viral infections and cancer because their synthetic changes enable targeted interruption of DNA or RNA production.
