Guanosine is a purine nucleoside comprising guanine attached to a ribose (ribofuranose) ring via a β-N9-glycosidic bond and there are no anhydride bond in guanosine.

The prefix "activated" usually means condensation of a sugar molecule like glucose with a nucleotide. Examples are uridine-5'-diphosphate (UDP) for activation of glucose, galactose or N-acetylglucosamine, guanosine-5'-diphosphate (GDP) for mannose or fucose and cytidine-5'-monophophate (CMP) for sialic acid.

Activation of sugars helps in biochemical transfer of sugar molecules to certain structure, e. g. N-glycans.

Guanosine monophosphate

guanosine

adenosene diphosphate