What is "inosine"

inosine \in"o*sine\ ([i^]n"[-o]*s[i^]n), n. (Chem.) A ribonucleoside ( C10H12N4O5) found in meat and meat extracts, differing from adenosine in having a hydroxyl rather than an amine attached to the purine ring. It may be prepared from adenosine by the enzyme adenosine deaminase, or by chemical deamination, as with nitrous acid. It participates in some cellular functions, but is not one of the normal nucleoside components of RNA.

n. (context biochemistry organic compound English) Any nucleoside formed from hypoxanthine attached to a ribose.

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