Ribosides

In biochemistry, a ribonucleotide is a nucleotide containing ribose as its pentose component. It is considered a molecular precursor of nucleic acids. Nucleotides are the basic building blocks of DNA and RNA. Ribonucleotides themselves are basic monomeric building blocks for RNA. Deoxyribonucleotides, formed by reducing ribonucleotides with the enzyme ribonucleotide reductase (RNR), are essential building blocks for DNA. There are several differences between DNA deoxyribonucleotides and RNA ribonucleotides. Successive nucleotides are linked together via phosphodiester bonds.

chemical compound

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.

chemical compound

flavor enhancer

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.

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.

Acadesine (INN), also known as 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, AICA-riboside, and AICAR, is an AMP-activated protein kinase activator which is used for the treatment of acute lymphoblastic leukemia and may have applications in treating other disorders such as diabetes. Acadesine has been used clinically to treat and protect against cardiac ischemic injury. The drug was first used in the 1980s as a method to preserve blood flow to the heart during surgery.

Tiazofurin is a drug which acts as an inhibitor of the enzyme IMP dehydrogenase. Tiazofurin and its analogues were under investigation for potential use in the treatment of cancer, though side effects such as pleuropericarditis and a flu-like syndrome precluded further development. They also show antiviral effects and may be reevaluated as potential options in the treatment of newly emerging viral diseases. ==Synthesis== [[File:Tiazofurin synthesis.svg|thumb|center|500px|ChemDrug Synthesis:]] The treatment of 1-O-Acetyl-2,3,5-tri-O-benzoyl-beta-D-ribofuranose [6974-32-9] (1) with trimethylsily