Compound as reactive (1)
xanthosine + S-adenosyl-L-methionine → S-adenosyl-L-homocysteine + 7-methylxanthosine
Compound as product (2)
H2O + XMP → xanthosine + phosphate
H2O + guanosine + H+ → xanthosine + ammonium
Reversible reaction (1)
xanthosine + phosphate ↔ xanthine + α-D-ribose-1-phosphate