Inosine

Inosine

Clinical data
AHFS/Drugs.com	International Drug Names
ATC code	D06BB05 (WHO) G01AX02 (WHO) S01XA10 (WHO)
Legal status
Legal status	In general: Over-the-counter (OTC)
Pharmacokinetic data
Metabolism	Hepatic
Identifiers
IUPAC name 9-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-6,9-dihydro-3H-purin-6-one
CAS Number	58-63-9 Y
PubChem CID	6021
IUPHAR/BPS	4554
DrugBank	DB04335 N
ChemSpider	5799 Y
UNII	5A614L51CT
KEGG	C00294 Y
ChEBI	CHEBI:17596 Y
ChEMBL	CHEMBL1556 N
ECHA InfoCard	100.000.355
Chemical and physical data
Formula	C10H12N4O5
Molar mass	268.23 g/mol
3D model (Jmol)	Interactive image
SMILES c1[nH]c2c(c(=O)n1)ncn2[C@H]3[C@@H]([C@@H]([C@H](O3)CO)O)O
InChI InChI=1S/C10H12N4O5/c15-1-4-6(16)7(17)10(19-4)14-3-13-5-8(14)11-2-12-9(5)18/h2-4,6-7,10,15-17H,1H2,(H,11,12,18)/t4-,6-,7-,10-/m1/s1 Y Key:UGQMRVRMYYASKQ-KQYNXXCUSA-N Y

Inosine is a nucleoside that is formed when hypoxanthine is attached to a ribose ring (also known as a ribofuranose) via a β-N₉-glycosidic bond.

Inosine is commonly found in tRNAs and is essential for proper translation of the genetic code in wobble base pairs.

Knowledge of inosine metabolism has led to advances in immunotherapy in recent decades. Inosine monophosphate is oxidised by the enzyme inosine monophosphate dehydrogenase, yielding xanthosine monophosphate, a key precursor in purine metabolism. Mycophenolate mofetil is an anti-metabolite, anti-proliferative drug that acts as an inhibitor of inosine monophosphate dehydrogenase. It is used in the treatment of a variety of autoimmune diseases including granulomatosis with polyangiitis because the uptake of purine by actively dividing B cells can exceed 8 times that of normal body cells, and, therefore, this set of white cells (which cannot operate purine salvage pathways) is selectively targeted by the purine deficiency resulting from inherited metabolic diseases (IMD) inhibition.

Adenine is converted to adenosine or inosine monophosphate (IMP), either of which, in turn, is converted into inosine (I), which pairs with adenine (A), cytosine (C), and uracil (U).

Purine nucleoside phosphorylase intraconverts inosine and hypoxanthine.