|Section2= |Section3= }} Guanosine's 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's attached to a deoxyribose ring, it's known as a deoxyguanosine. Guanosine's structure bears similarities to that of the antiviral drug aciclovir, often used in Herpes… (More on Guanosine)