Sirolimus

**Semantic type:** Antibiotic|Organic Chemical|Pharmacologic Substance

**Definition:** A natural macrocyclic lactone produced by the bacterium Streptomyces hygroscopicus, with immunosuppressant properties. In cells, sirolimus binds to the immunophilin FK Binding Protein-12 (FKBP-12) to generate an immunosuppressive complex that binds to and inhibits the activation of the mammalian Target Of Rapamycin (mTOR), a key regulatory kinase. This results in inhibition of T lymphocyte activation and proliferation that occurs in response to antigenic and cytokine (IL-2, IL-4, and IL-15) stimulation and inhibition of antibody production. (NCI04)

**Synonyms:** - 9,10,12,13,14,21,22,23,24,25,26,27,32,33,34,34a-Hexadecahydro-9,27-dihydroxy-3-((1R)-2-((1S,3R,4R)-4-hydroxy-3-methoxycyclohexyl)-1-methylethyl)-10,21-dimethoxy-6,8,12,14,20,26-hexamethyl-23,27-epoxy-3H-pyrido(2,1-c)(1,4)oxaazacyclohentriacontine-1,5,11,2 - AY 22989 - AY-22989 - AY22989 - RAPA - RAPAMYCIN - Rapamune - Rapamune - Rapamycin - SILA 9268A - SILA-9268A - SILA9268A - SIROLIMUS - WY 090217 - WY-090217 - WY090217 - rapamycin - sirolimus