Nucleosides

Nucleosides are the structural subunit of nucleic acids such as DNA and RNA. A nucleoside, composed of a nucleobase, is either a pyrimidine (cytosine, thymine or uracil) or a purine (adenine or guanine), a five carbon sugar which is either ribose or deoxyribose. 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.

References

Galmarini, Carlos M.; MacKey, John R.; Dumontet, Charles (2002). “Nucleoside analogues and nucleobases in cancer treatment”. The Lancet Oncology. 3 (7): 415–424. doi:10.1016/S1470-2045(02)00788-X. PMID 12142171.

Gaofei Lu, Gregory GR., Shuli Mao, Michael Hager, Bharat Gurale, Paul Collop, Damien Kuiper, Kasinath Sana, George R. Painter, Abel De La Rosa, Alexander A. Kolykhalov. “Simple In Vitro Assay To Evaluate the Incorporation Efficiency of Ribonucleotide Analog 5’-Triphosphates into RNA by Human Mitochondrial DNA-Dependent RNA Polymerase”.  Antimicrobial Agents and Chemotherapy. 2018, 62 (2) e01830-17. https://journals.asm.org/doi/full/10.1128/AAC.01830-17