Guanosine

Guanosine is a nucleoside comprising guanine attached to a ribose (ribofuranose) ring via a β-N9-glycosidic bond.

Guanosine can be phosphorylated to become GMP (guanosine monophosphate), cGMP (cyclic guanosine monophosphate), GDP (guanosine diphosphate) and GTP (guanosine triphosphate).

When guanine is attached to a deoxyribose ring, it is known as a deoxyguanosine.