The practical consequence of this limited solu bility in water is that uric acid, the main metabo- lite of can form precipitates. As a conse- quence, overproduction of urate and its insolubility contribute to the pathogenesis of tion of urate contributes to inflammation, tophi and tendons), (urate deposits in the skin, joints and urolithiasis (kidney stones). 4 Nucleosides consist of a purine or pyrimidine base attached to a sugar through an energy-poor B-glycosidic bond. Naturally occurring pentose sugars include ribose and 2-deoxyribose (Figure 6 130. When the sugar is attached to a base, the numbered carbon atoms of the sugar are given a prime designation to distinguish them from posi- tions of atoms in the base. The 2' of 2'-deoxyribose refers to C2 of the sugar. Ribonucleosides contain ribose, and 2'-deoxyribonucleosides contain deoxy