- A compound of a sugar (usually ribose or deoxyribose) with a purine or pyrimidine base by way of an N-glycosyl link.- n. bisphosphate a n. that carries two independent ( i.e., not linked to each other) phosphoric residues. Cf.:n. diphosphate.- n. diphosphate (NDP) the pyrophosphoric ester of a n., i.e., a n. in which the H of one of the ribose hydroxyls (usually the 5′) is replaced by a pyrophosphoric (diphosphoric) radical; e.g., adenosine 5′-diphosphate. Cf.:n. bisphosphate.- n. triphosphate a n. in which the H of one of the ribose hydroxyls (usually the 5′) is replaced by a triphosphoric group, –PO(OH)–O–PO(OH)–O–PO(OH)2 or the corresponding conjugate base; e.g., adenosine triphosphate.
* * *nu·cle·o·side 'n(y)ü-klē-ə-.sīd n a compound (as guanosine or adenosine) that consists of a purine or pyrimidine base combined with deoxyribose or ribose and is found esp. in DNA or RNA compare NUCLEOTIDE
* * *n.a compound consisting of a nitrogen-containing base (a purine or pyrimidine) linked to a sugar. Examples are adenosine, guanosine, cytidine, thymidine, and uracil.
* * *nu·cleo·side (nooґkle-o-sīd″) a heterocyclic nitrogenous base, particularly a purine or pyrimidine, in N-glycosidic linkage with a sugar, particularly a pentose; it is often used specifically to denote a compound obtained by hydrolysis of nucleic acids, a purine or pyrimidine linked to ribose or deoxyribose, e.g., adenosine or cytidine.
Medical dictionary. 2011.