2'-Deoxyguanosine 5'-monophosphate (dGMP) is used as a substrate of guanylate kinases to generate dGDP, which in turn is phosphorylated to dGTP, a nucleotide precursor used in DNA synthesis. In addition, dGMP can be efficiently phosphorylated by the type I thymidylate kinase of the malarial agent P. falciparum. In humans, deficiency of mitochondrial deoxyguanosine kinase, which synthesizes dGMP from ATP and deoxyguanosine, contributes to mitochondrial DNA depletion syndrome.
Sildenafil nitrate is a selective inhibitor of PDE5 (type 5 cGMP phosphodiesterase) which catalyzes the hydrolysis of 3',5'-cyclic guanosinemonophosphate (cGMP).