|Section2= |Section3= }} 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's known as a deoxyguanosine.… (More on Guanosine)