4-Carbamoyl-1-Beta-D-Ribofuranosyl-Imidazolium-5-Olate-5'-Phosphate

4-Carbamoyl-1-Beta-D-Ribofuranosyl-Imidazolium-5-Olate-5'-Phosphate, also known as Mizoribine 5'-monophosphate, is the active metabolite of the immunosuppressant drug Mizoribine. Mizoribine itself is an imidazole nucleoside initially isolated from the fungus Eupenicillium brefeldianum. Upon administration, Mizoribine is converted into this active phosphorylated form. Its mechanism of action involves the selective inhibition of inosine monophosphate dehydrogenase (IMPDH) and guanosine monophosphate synthetase, key enzymes in the de novo synthesis pathway of guanine nucleotides. By blocking this pathway, the drug effectively suppresses the proliferation of lymphocytes (T and B cells), thereby exerting its immunosuppressive effects. It is primarily used to prevent organ transplant rejection and to treat various autoimmune diseases such as lupus nephritis, rheumatoid arthritis, steroid-resistant nephrotic syndrome, and IgA nephropathy. The drug was developed by the Japanese pharmaceutical company Asahi Kasei and is administered orally.

Other names

Mizoribine 5'-monophosphateMizoribine 5'-phosphateMZ-5-PMZ5-PMZ 5-PMZB-5'P5-Hydroxy-1-(5-O-phosphono-β-D-ribofuranosyl)-1H-imidazole-4-carboxamide