＞98%

Store at -20℃ for one year（Powder）；Store at 2-4℃ for two weeks；Store at -20℃ for six months after dissolution.

枸橼酸托法替尼；Tasocitinib citrate；CP-690550 citrate

White to off-white powder

DMSO ：50.5 mg/mL (100 mM)

JAK3,JAK2

Tofacitinib citrate inhibits IL-2-mediated human T cell blast proliferation and IL-15-induced CD69 expression with IC50 of 11 nM and 48 nM, respectively. Tofacitinib citrate prevents mixed lymphocyte reaction with IC50 of 87 nM. Tofacitinib citrate treatment of murine factor-dependent cell Patersen–erythropoietin receptor (FDCP-EpoR) cells harboring human wild-type or V617F JAK2 leads to prevention of cell proliferation with IC50 of 2.1 µM and 0.25 µM, respectively. Tofacitinib citrate inhibits interleukin-6-induced phosphorylation of STAT1 and STAT3 with IC50 of 23 nM and 77 nM, respectively. Moreover, Tofacitinib citrate generates a significant pro-apoptotic effect on murine FDCP-EpoR cells carrying JAK2VV617F, whereas a lesser effect is observed for cells carrying wild-type JAK2. This activity is coupled with the inhibition of phosphorylation of the key JAK2V617F-dependent downstream signaling effectors signal transducer and activator of transcription (STAT)3, STAT5, and v-akt murine thymoma viral oncogene homolog (AKT). Additionally, Tofacitinib citrate prevents IL-15-induced CD69 expression in human and cynomolgus monkey NK and CD8+ T cells in vitro.

Tofacitinib citrate decrease a delayed-type hyper-sensitivity response and extended cardiac allograft survival in murine models. Furthermore, Tofacitinib citrate treatment of ex-vivo-expanded erythroid progenitors from JAK2V617F-positive PV patients results in specific, antiproliferative (IC50 = 0.2 μM) and pro-apoptotic activity. In contrast, expanded progenitors from healthy controls are less sensitive to Tofacitinib citrate in proliferation (IC50 > 1.0 μM), and apoptosis assays. During 2 weeks of Tofacitinib citrate dosing at 10 and 30 mg/kg/d, a significant, time-dependent decrease in NK cell numbers relative to vehicle treatment is observed. Effector memory CD8+ cell numbers in the Tofacitinib citrate-treated group are 55% less than those observed in animals treated with vehicle.