Chemically created substances known as synthetic nucleoside analogs are intended to replicate the structure and capabilities of natural nucleosides. The building blocks of nucleic acids, such as DNA and RNA, are called nucleosides, and they are made up of a sugar molecule and a nitrogenous base. Artificial counterparts alter these elements to obstruct biological functions, especially in the field of medicine.These analogs are essential components of antiviral and anticancer treatments. They can be incorporated into the DNA and RNA of viruses or cancer cells by emulating natural nucleosides, which can result in replication mistakes and ultimately cause cell death. For example, medications such as zidovudine (AZT) and acyclovir are used to treat HIV and herpes simplex virus, respectively. The active triphosphate versions of these medications are phosphorylated within the cell, inhibiting the vital enzymes required for viral replication, reverse transcriptase and viral DNA polymerase. Nucleoside analogues like cytarabine (Ara-C) and 5-fluorouracil (5-FU) are utilized in the treatment of cancer. When Ara-C is integrated into DNA during replication, 5-FU inhibits thymidylate synthase, an enzyme essential for DNA synthesis and causes chain termination. These strategies reduce the proliferation of cancer cells by specifically targeting those that divide quickly.Careful modification is required during the construction of synthetic nucleoside analogues in order to improve specificity, lower toxicity, and overcome resistance. One tactic is to change the sugar moiety; gemcitabine is an example of this, since it has two fluorine atoms in place of hydrogen atoms to improve its stability and DNA integration. A different strategy involves changing the nitrogenous base, such as 6-mercaptopurine, which interferes with DNA and RNA production by incorporating sulfur into the purine base. Prodrugs, such as sofosbuvir for hepatitis C, are examples of recent advances in medicine. They improve bioavailability and targeting by being converted into active forms within the body. Nucleoside analogues can also be conjugated with other compounds to improve transport to particular tissues, so maximizing therapeutic efficacy and reducing side effects. All things considered, synthesized nucleoside analogues are essential to contemporary pharmacotherapy. Viral infections and malignancies can be effectively treated by them due to their unique capacity to selectively interrupt the production of nucleic acids. Research is still being done to improve these molecules in order to treat different diseases more broadly and more effectively.
