Inosine is a purine nucleoside in which hypoxanthine is attached to ribofuranose via a beta-N(9)-glycosidic bond. It has a role as a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite and a mouse metabolite. It is a purines D-ribonucleoside and a member of inosines. It derives from a hypoxanthine and a ribofuranose.