Nucleosides

Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9-glycosidic bond. Adenosine is one of the four nucleoside building blocks of RNA (and its derivative deoxyadenosine is a building block of DNA), which are essential for all life on Earth. Its derivatives include the energy carriers adenosine mono-, di-, and triphosphate, also known as AMP/ADP/ATP. Cyclic adenosine monophosphate (cAMP) is pervasive in signal transduction. Adenosine is used as an intravenous medication for

Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups. In a nucleoside, the anomeric carbon is linked through a glycosidic bond to the N9 of a purine or the N1 of a pyrimidine. Nucleotides are the molecular building blocks of DNA and RNA.

Uridine (symbol U or Urd) is a glycosylated pyrimidine analog containing uracil attached to a ribose ring (or more specifically, a ribofuranose) via a β-N1-glycosidic bond. The analog is one of the five standard nucleosides which make up nucleic acids, the others being adenosine, thymidine, cytidine and guanosine. The five nucleosides are commonly abbreviated to their symbols, U, A, dT, C, and G, respectively. However, thymidine is more commonly written as 'dT' ('d' represents 'deoxy') as it contains a 2'-deoxyribofuranose moiety rather than the ribofuranose ring found in uridine. This is beca

Guanosine (symbol G or Guo) is a purine nucleoside comprising guanine attached to a ribose (ribofuranose) ring via a β-N9-glycosidic bond. Guanosine can be phosphorylated to become guanosine monophosphate (GMP), cyclic guanosine monophosphate (cGMP), guanosine diphosphate (GDP), and guanosine triphosphate (GTP). These forms play important roles in various biochemical processes such as synthesis of nucleic acids and proteins, photosynthesis, muscle contraction, and intracellular signal transduction (cGMP). When guanine is attached by its N9 nitrogen to the C1 carbon of a deoxyribose ring it is

Thymidine (symbol dT or dThd), also known as deoxythymidine is a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. In cell biology it is used to synchronize the cells in G1/early S phase. The prefix deoxy- is often left out since there are no precursors of thymine nucleotides involved in RNA synthesis.

Cytidine (symbol C or Cyd) is a nucleoside molecule that is formed when cytosine is attached to a ribose ring (also known as a ribofuranose) via a β-N1-glycosidic bond. Cytidine is a component of RNA. It is a white water-soluble solid that is only slightly soluble in ethanol.

Lamivudine, commonly called 3TC, is an antiretroviral medication used to prevent and treat HIV/AIDS. It is also used to treat chronic hepatitis B when other options are not possible. It is effective against both HIV-1 and HIV-2. It is typically used in combination with other antiretrovirals such as zidovudine, dolutegravir, and abacavir. Lamivudine may be included as part of post-exposure prevention in those who have been potentially exposed to HIV. Lamivudine is taken by mouth as a liquid or tablet.

Inosine is a nucleoside that is formed when hypoxanthine is attached to a ribose ring (also known as a ribofuranose) via a β-N9-glycosidic bond. It was discovered in 1965 in analysis of RNA transferase. Inosine is commonly found in tRNAs and is essential for proper translation of the genetic code in wobble base pairs. thumb|right|225px|Wobble base pairs for inosine and [[guanine]]

Cytarabine, also known as cytosine arabinoside (ara-C), is a chemotherapy medication used to treat acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), chronic myelogenous leukemia (CML), and non-Hodgkin's lymphoma. It is given by injection into a vein, under the skin, or into the cerebrospinal fluid. There is a liposomal formulation for which there is tentative evidence of better outcomes in lymphoma involving the meninges.

Deoxycytidine is a deoxyribonucleoside, a component of deoxyribonucleic acid. It is similar to the ribonucleoside cytidine, but with one hydroxyl group removed from the C2' position. Deoxycytidine can be phosphorylated at C5' of the deoxyribose by deoxycytidine kinase, converting it to deoxycytidine monophosphate (dCMP), a DNA precursor. dCMP can be converted to dUMP and dTMP.

Deoxyadenosine (symbol dA or dAdo) is a deoxyribonucleoside. It is a derivative of the nucleoside adenosine, differing from the latter by the replacement of a hydroxyl group (-OH) by hydrogen (-H) at the 2′ position of its ribose sugar moiety. Deoxyadenosine is the DNA nucleoside A, which pairs with deoxythymidine (T) in double-stranded DNA.

Puromycin is an antibiotic protein synthesis inhibitor which causes premature chain termination during translation.

Pseudouridine (5-ribosyluracil, abbreviated by the Greek letter psi- Ψ) is an isomer of the nucleoside uridine in which the uracil is attached via a carbon-carbon instead of a nitrogen-carbon glycosidic bond.

'''S-Adenosyl-L-homocysteine (SAH') is the biosynthetic precursor to homocysteine. SAH is formed by the demethylation of S''-adenosyl-L-methionine. Adenosylhomocysteinase converts SAH into homocysteine and adenosine.

The chemical compound 5-methyluridine (symbol m5U), also called ribothymidine (rT), is a pyrimidine nucleoside. It is the ribonucleoside counterpart to the deoxyribonucleoside thymidine, which lacks a hydroxyl group at the 2' position. 5-Methyluridine contains a thymine base joined to a ribose pentose sugar. It is a white solid.

Deoxyuridine (dU) is a compound and a nucleoside. It belongs to a class of compounds known as Pyrimidine 2'-deoxyribonucleosides and closely resembles the chemical composition of uridine but without the presence of the 2' hydroxyl group. Idoxuridine and Trifluridine are variants of deoxyuridine used as antiviral drugs. They are similar enough to be incorporated as part of DNA replication, but they possess side groups on the uracil component (an iodine and a CF3 group, respectively), that prevent base pairing. A known use of dU is as a precursor in the synthesis of Edoxudine.

Nelarabine, sold under the brand names Arranon (US) and Atriance (EU), is a chemotherapy medication used for the treatment of T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL).

Azacitidine, sold under the brand name Vidaza among others, is a medication used for the treatment of myelodysplastic syndrome, myeloid leukemia, and juvenile myelomonocytic leukemia. It is a chemical analog of cytidine, a nucleoside in DNA and RNA. Azacitidine and its deoxy derivative, decitabine (also known as 5-aza-2′-deoxycytidine) were first synthesized in Czechoslovakia as potential chemotherapeutic agents for cancer.

Idoxuridine is an anti-herpesvirus antiviral drug.

Dihydrouridine (abbreviated as D, hU, DHU, or UH2) is a pyrimidine nucleoside which is the result of adding two hydrogen atoms to a uridine, making it a fully saturated pyrimidine ring with no remaining double bonds. D is found in tRNA and rRNA molecules as a nucleoside; the corresponding nucleobase is 5,6-dihydrouracil.

Telbivudine is an antiviral drug used in the treatment of hepatitis B infection. It is marketed by Swiss pharmaceutical company Novartis under the trade names Sebivo (European Union) and Tyzeka (United States). Clinical trials have shown it to be significantly more effective than lamivudine or adefovir, and less likely to cause resistance. However, HBV signature resistance mutation M204I (a change from methionine to isoleucine at position 204 in the reverse transcriptase domain of the hepatitis B polymerase) or L180M+M204V have been associated with Telbivudine resistance.

Bromodeoxyuridine ('''5-bromo-2'-deoxyuridine, BrdU, BUdR, BrdUrd, broxuridine''') is a synthetic nucleoside analogue with a chemical structure similar to thymidine. BrdU is commonly used to study cell proliferation in living tissues and has been studied as a radiosensitizer and diagnostic tool in people with cancer.

Pentostatin (or 2′-deoxycoformycin, trade name Nipent, manufactured by SuperGen) is an anticancer chemotherapeutic drug.

Decitabine (i.e., 5-aza-2′-deoxycytidine), sold under the brand name Dacogen among others, acts as a nucleic acid synthesis inhibitor. It is a medication for the treatment of myelodysplastic syndromes, a class of conditions where certain blood cells are dysfunctional, and for acute myeloid leukemia (AML). Chemically, it is a cytidine analog.

A ribonucleoside is a type of nucleoside including ribose as a component. They are analogous to the nucleosides that, along with a phosphate group, form nucleotides that are the functional units of DNA; however, ribonucleosides are principal components of RNA. These form ribonucleotides with the addition of a phosphate group, which chain to form a molecule of RNA.

Cordycepin, or '''3'-deoxyadenosine''', is a derivative of the nucleoside adenosine, differing from the latter by the replacement of the hydroxy group in the 3' position with a hydrogen. It was initially extracted from the fungus Cordyceps militaris, but can now be produced synthetically.

7-Methylguanosine (m7G) is a modified purine nucleoside. It is a methylated version of guanosine and when found in human urine, it may be a biomarker of some types of cancer. In the RNAs, 7-methylguanosine have been used to study and examine the reaction evolving methylguanosine. It also participates in the formation of 5'-cap that stabilizes mRNA and prevents its degradation by 5' exonucleases.

Maribavir, sold under the brand name Livtencity, is an antiviral medication that is used to treat post-transplant cytomegalovirus (CMV). Maribavir is a cytomegalovirus pUL97 kinase inhibitor that works by preventing the activity of human cytomegalovirus enzyme pUL97, thus blocking virus replication.

Xanthosine is a nucleoside derived from xanthine and ribose. It is the biosynthetic precursor to 7-methylxanthosine by the action of 7-methylxanthosine synthase. 7-Methylxanthosine in turn is the precursor to theobromine (active alkaloid in chocolate), which in turn is the precursor to caffeine, the alkaloid in coffee and tea.

Floxuridine (also 5-fluorodeoxyuridine) is an oncology drug that belongs to the class known as antimetabolites. Specifically, floxuridine is a pyrimidine analog, classified as a deoxyuridine. The drug is usually administered via an artery, and most often used in the treatment of colorectal cancer. The quality of life and survival rates of individuals that receive continuous hepatic artery infusion of floxuridine for colorectal cancer metastases is significantly higher than control groups. Floxuridine can also be prescribed for the treatment of kidney and stomach cancers. In vitro uses of floxu

'''8-Oxo-2'-deoxyguanosine (8-oxo-dG''') is an oxidized derivative of deoxyguanosine. 8-Oxo-dG is one of the major products of DNA oxidation. Concentrations of 8-oxo-dG within a cell are a measurement of oxidative stress.

biochemical compound

REDIRECT Deoxyribonucleotide#Deoxyribonucleoside

5-Methylcytidine is a modified nucleoside derived from 5-methylcytosine. It is found in ribonucleic acids of animal, plant, and bacterial origin.

Brivudine (trade names Zostex, Mevir, Brivir, among others) is an antiviral drug used in the treatment of herpes zoster ("shingles"). Like other antivirals, it acts by inhibiting replication of the target virus.

chemical compound

Regadenoson, sold under the brand name Lexiscan among others, is an A2A adenosine receptor agonist that is a coronary vasodilator that is commonly used in pharmacologic stress testing. It produces hyperemia quickly and maintains it for a duration that is useful for radionuclide myocardial perfusion imaging. The selective nature of the drug makes it preferable to other stress agents such as adenosine, which are less selective and therefore cause more side-effects.

'''S-Adenosylmethioninamine' is a substrate that is required for the biosynthesis of polyamines including spermidine, spermine, and thermospermine. It is produced by decarboxylation of S''-adenosyl methionine.

Galidesivir (BCX4430, immucillin-A) is an antiviral drug, an adenosine analog (a type of nucleoside analog). It was developed by BioCryst Pharmaceuticals with funding from NIAID, originally intended as a treatment for hepatitis C, but subsequently developed as a potential treatment for deadly filovirus infections such as Ebola virus disease and Marburg virus disease, as well as Zika virus. Currently, galidesivir is under phase 1 human trial in Brazil for coronavirus.

Orotidine is a nucleoside formed by attaching orotic acid to a ribose ring via a β-N1-glycosidic bond. It is found in bacteria, fungi and plants. It was first isolated in 1951 from the fungus Neurospora by A. Michael Michelson, William Drell, and Herschel K. Mitchell. In humans, orotidine occurs as its 5'-phosphate (orotidylic acid), which is an intermediate in pyrimidine nucleotide biosynthesis (cytidine and uridine) that are found in nucleic acids. Orotidine itself is not a component of nucleic acid. Large amounts of orotidine are excreted in the urine of cancer patients treated with 6-azaur

8-Hydroxyguanosine is an RNA nucleoside which is an oxidative derivative of guanosine. Measurement of the levels of 8-hydroxyguanosine is used as a biomarker of oxidative stress causing RNA damage.

'''N6-Cyclopentyladenosine (CPA''') is a drug which acts as a selective adenosine A1 receptor agonist. It has mainly cardiovascular effects with only subtle alterations of behavior. CPA is widely used in scientific research into the adenosine receptors and has been used to derive a large family of derivatives.

The chemical compound 3-methyluridine, also called N3-methyluridine, is a pyrimidine nucleoside (abbreviated m3U). In living organisms it is present as RNA modification which has been detected in 23S rRNA of archaea, 16S and 23S rRNA of eubacteria, and 18S, 25S, and 28S of eukaryotic ribosomal RNAs.

'''N6-Methyladenosine (m6A') was originally identified and partially characterised in the 1970s, and is an abundant modification in mRNA and DNA. It is found within some viruses, and most eukaryotes including mammals, insects, plants and yeast. It is also found in tRNA, rRNA, and small nuclear RNA (snRNA) as well as several long non-coding RNA, such as Xist''.

5-Ethynyl-2′-deoxyuridine (EdU) is a thymidine analogue which is incorporated into the DNA of dividing cells. EdU is used to assay DNA synthesis in cell culture and detect cells in embryonic, neonatal and adult animals which have undergone DNA synthesis. Whilst at high doses it can be cytotoxic, this molecule is now widely used to track proliferating cells in multiple biological systems.

CGS-21680 is a specific adenosine A2A subtype receptor agonist. It is usually presented as an organic hydrochloride salt with a molecular weight of 536.0 g/M. It is soluble up to 3.4 mg/mL in DMSO and 20 mg/mL in 45% (w/v) aq 2-hydroxypropyl-β-cyclodextrin.

4-Thiouridine is an atypical nucleoside formed with the 4-thiouracil base found in transfer RNA (tRNA). Its biosynthesis has been determined.

In biochemistry, wybutosine (yW) is a heavily modified nucleoside of phenylalanine transfer RNA that stabilizes interactions between the codons and anti-codons during protein synthesis. Ensuring accurate synthesis of protein is essential in maintaining health as defects in tRNA modifications are able to cause disease. In eukaryotic organisms, it is found only in position 37, 3'-adjacent to the anticodon, of phenylalanine tRNA. Wybutosine enables correct translation through the stabilization of the codon-anticodon base pairing during the decoding process.

chemical compound

FV-100, also known as Cf1743, is an orally available nucleoside analogue drug with antiviral activity. It may be effective against shingles.

CP-532,903 is a selective adenosine A3 subtype receptor agonist. It has antiinflammatory effects and has been shown to reduce superoxide generation in damaged tissues, and protects against tissue damage following myocardial ischemia, mediated via an interaction with ATP-sensitive potassium channels.

N1-Methylpseudouridine (abbreviated m1Ψ) is a natural archaeal tRNA component, and "hypermodified" pyrimidine nucleoside used in biochemistry and molecular biology for in vitro transcription and is found in the SARS-CoV-2 mRNA vaccines tozinameran (Pfizer–BioNTech) and elasomeran (Moderna).

5,6-Dichloro-1-β--ribofuranosylbenzimidazole (DRB) is a chemical compound that inhibits transcription elongation by RNA Polymerase II. Sensitivity to DRB is dependent on DRB sensitivity inducing factor (DSIF), negative elongation factor (NELF), and positive transcription elongation factor b (P-TEFb). DRB is a nucleoside analog and also inhibits some protein kinases.

Queuosine is a modified nucleoside that is present in certain tRNAs in bacteria and eukaryotes. It contains the nucleobase queuine. Originally identified in E. coli, queuosine was found to occupy the first anticodon position of tRNAs for histidine, aspartic acid, asparagine and tyrosine. The first anticodon position pairs with the third "wobble" position in codons, and queuosine improves accuracy of translation compared to guanosine. Synthesis of queuosine begins with GTP. In bacteria, three structurally unrelated classes of riboswitch are known to regulate genes that are involved in the synth

Zebularine is a nucleoside analog of cytidine. It is a transition state analog inhibitor of cytidine deaminase by binding to the active site as covalent hydrates. Also shown to inhibit DNA methylation and tumor growth both in vitro and in vivo.

Tezacitabine is a ribonucleotide reductase inhibitor. It is a synthetic purine nucleoside analogue with potential antineoplastic activity. It is used in synthetic DNA.

Doxifluridine (5'-deoxy-5-fluorouridine) is a second generation nucleoside analog prodrug developed by Roche and used as a cytostatic agent in chemotherapy in several Asian countries including China and South Korea. Doxifluridine is not FDA-approved for use in the USA. It is currently being evaluated in several clinical trials as a stand-alone or combination therapy treatment.

GS-441524 is a nucleoside analogue antiviral drug which was developed by Gilead Sciences. It is the main plasma metabolite of the antiviral prodrug remdesivir, and has a half-life of around 24 hours in human patients. Remdesivir and GS-441524 were both found to be effective in vitro against feline coronavirus strains responsible for feline infectious peritonitis (FIP), a lethal systemic disease affecting domestic cats. Remdesivir was never tested in cats (though some vets now offer it), but GS-441524 has been found to be effective treatment for FIP.

5′-Methylthioadenosine is S-methyl derivative of the adenosine. It is an intermediate in the methylthioadenosine (MTA) cycle, also known as the methionine salvage pathway that is universal to aerobic life.