purinesugar

Purinesugar is a descriptive term sometimes used to refer to compounds in which a purine base is covalently linked to a sugar moiety, forming purine nucleosides. In standard biochemistry, these compounds are known as purine nucleosides. The most common examples are adenosine (adenine attached to ribose) and guanosine (guanine attached to ribose). When the sugar is deoxyribose, the corresponding nucleosides are part of DNA building blocks.

Structure and chemistry. In purine nucleosides the purine base is attached to the sugar through a glycosidic bond between the N9 atom of the purine and the C1′ atom of the sugar, typically in a beta configuration. The sugar is usually ribose in RNA or deoxyribose in DNA. The glycosidic bond type and sugar identity influence the properties and reactivity of the nucleoside, including its involvement in nucleotide synthesis and salvage pathways.

Biological significance. Purine nucleosides serve as key intermediates in nucleotide metabolism, acting as monomeric units for the synthesis of purine nucleotides. They participate in salvage pathways that recycle purine bases to nucleosides and nucleotides, and some serve signaling roles (for example, adenosine acts in various physiological signaling pathways). Purine nucleosides also contribute to energy transfer and storage in the cell through related molecules like ATP, which contains adenosine.

Terminology note. The term purinesugar is not a standard scientific designation; it is a generic label that might be used to describe the purine–sugar linkage in nucleosides. For precision, the terms purine nucleoside or specific names (adenosine, guanosine) are preferred. See also nucleoside, nucleotide, ribose, deoxyribose, adenosine, guanosine.