Reaction: PNP trimer transforms RBV to T-CONH2
- in pathway: Ribavirin ADME
Significant amounts of ribavirin (RBV) are phosphorolyzed to 1,2,4-triazole-3-carboxamide (T-CONH2), already in the first pass through intestinal cells. The responsible enzyme purine nucleoside phosphorylase (PNP) is expressed in higher amounts in the small intestine than in the liver, which also correlates with higher cytosolic phosphorolysis activity in intestinal cells. The amount of conversion to T-CONH2 in the liver is additionally reduced by phosphorylation of RBV to RBV-MP. T-CONH2 from this reaction is the major metabolite detectable in urine (Paroni et al, 1989; Furihata et al, 2014).
Reaction - small molecule participants:
T-CONH2 [cytosol]
R1P [cytosol]
phosphate [cytosol]
Reactome.org reaction link: R-HSA-9755044
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Reaction input - small molecules:
phosphate(3-)
Reaction output - small molecules:
1,2,4-triazole-3-carboxamide
alpha-D-ribose 1-phosphate(2-)
Reactome.org link: R-HSA-9755044