EX527, 10 mg

From STEMCELL Technologies, this small molecule is a cell-permeable, selective inhibitor of mammalian sirtuin 1 (SIRT1), with an IC₅₀ of 98 nM, and shows selectivity over SIRT2 and SIRT3 with no activity against other histone deacetylases. SIRT1 is an NAD⁺-dependent deacetylase involved in energy metabolism and inflammation, and the compound is reported to inhibit sirtuins by forming a trimeric complex with an NAD⁺-derived coproduct.

The active substance, also known by the synonym Selisistat, is 6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide (CAS 49843-98-3), with the molecular formula C₁₃H₁₃ClN₂O and a molecular weight of 248.7 g/mol. It is supplied as a crystalline solid with a stated purity of ≥ 98%. The product is stable at -20°C as supplied, should be protected from prolonged exposure to light, and is stable as supplied for 12 months from the date of receipt. According to the manufacturer's safety documentation, the substance is classified as acutely toxic if swallowed (Category 3) and causes serious eye irritation (Category 2A). The product is for research use only and is not intended for human or animal diagnostic or therapeutic applications.

Published studies have described applications in differentiation, where it increased oligodendrocyte production from neural stem and progenitor cells; in immunology, where it restored microvascular responses during the hypoinflammatory phase in a mouse sepsis model; and in disease modeling, where it delayed cyst growth in kidneys of PKD1 knockout mouse models.