DEFINITION

The nucleotides are compounds in which nitrogenous bases (purine and pyrimidine) are conjugated to the pentose sugars (ribose or deoxyribose) by a β-glycosidic linkage. The β-glycosidic linkage involves C-1 of sugar and the hydrogen atom of N-9 (in the case of purines) or N-1 (in the case of pyrimidine).