mizoribine mizoribine mizoribine (inn, trade name bredinin) is an immunosuppressive drug. the compound was first observed in tokyo, japan, in 1971. first isolated from the fungus penicillium brefeldianum. mizoribine (mzb) is an imidazole nucleoside that has been used in renal transplantation, and in steroid-resistant nephrotic syndrome, iga nephropathy, lupus, as well as for adults with rheumatoid arthritis, lupus nephritis and other rheumatic diseases. mzb exerts its activity through selective inhibition of inosine monophosphate synthetase and guanosine monophosphate synthetase, resulting in the complete inhibition of guanine nucleotide synthesis without incorporation into nucleotides. it arrests dna synthesis in the s phase of cellular division. thus, mzb has less toxicity than azathioprine, another immunosuppressant used for some of the same diseases. mizoribineclinical dataother names1--5-hydroxyimidazole-4-carboxamideahfs/drugs.cominternational drug namesroutes ofadministrationoralatc codenonelegal statuslegal status in general: ℞ (prescription only) identifiers iupac name 5-hydroxy-1-β-d-ribofuranosyl-1h-imidazole-4-carboxamide cas number50924-49-7 ypubchem cid104762chemspider94571unii4jr41a10vpkeggd01392 ycomptox dashboard (epa)dtxsid8045777 echa infocard100.164.876 chemical and physical dataformulac9h13n3o6molar mass259.218 g·mol−13d model (jsmol)interactive image smiles c1=nc(=c(n12(((o2)co)o)o)o)c(=o)n inchi inchi=1s/c9h13n3o6/c10-7(16)4-8(17)12(2-11-4)9-6(15)5(14)3(1-13)18-9/h2-3,5-6,9,13-15,17h,1h2,(h2,10,16)/t3-,5-,6-,9-/m1/s1key:hzqdcmwjebcwbr-uuokfmhzsa-n (verify)