Nucleosides and nucleotides
How do nucleosides form?
Biomolecule
Denufosol Angustmycin Synthesis of nucleosides Purinergic signalling Arabinosyl nucleosides
Denufosol-Chemistry Angustmycin-Abstract Synthesis_of_nucleosides-Other_Methods_for_Nucleoside_Synthesis Purinergic_signalling-Abstract Arabinosyl_nucleosides-Abstract
Denufosol consists of two nucleosides (composed of a nucleobase and a sugar each), 2'-desoxycytidine and uridine, linked by four units of phosphoric acid. It is used in form of its tetrasodium salt. 
Angustmycins are bio-active nucleosides. 
Transglycosylation, which involves the reversible transfer of a sugar moiety from one heterocyclic base to another, is effective for the conversion of pyrimidine nucleosides to purine nucleosides. Most other transglycosylation reactions are low yielding due to a small thermodynamic difference between equilibrating nucleosides. Deoxyribose-derived electrophiles are unable to form the cyclic cation 1; as a result, the stereoselective synthesis of deoxyribonucleosides is more difficult than the synthesis of ribonucleosides. One solution to this problem involves the synthesis of a ribonucleoside, followed by protection of the 3'- and 5'-hydroxyl groups, removal of the 2'-hydroxyl group through a Barton deoxygenation, and deprotection. 
Purinergic signalling (or signaling: "see American and British English differences") is a form of extracellular signalling mediated by purine nucleotides and nucleosides such as adenosine and ATP, leading to the activation of purinergic receptors in the cell and/or in nearby cells, thereby regulating cellular functions. 
Arabinosyl nucleosides are derivatives of the nucleosides. They contain – in contrast to most nucleosides – instead of the β-D-Ribofuranose the β-D-Arabinofuranose. They are mostly used as cytostatics or virostatics. 