R406

Cas No.:	841290-81-1
Chemical Name:	6-(5-fluoro-2-(3,4,5-trimethoxyphenylamino)pyrimidin-4-ylamino)-2,2-dimethyl-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one benzenesulfonate
Synonyms:	R406,R-406
SMILES:	O1C(C)(C)C(=O)NC2=NC(NC3C(F)=CN=C(NC4=CC(OC)=C(OC)C(OC)=C4)N=3)=CC=C12.C(S(O)(=O)=O)1=CC=CC=C1
Formula:	C28H29FN6O8S
M.Wt:	628.63
Sotrage:	2 years -20°C Powder, 2 weeks 4°C in DMSO, 6 months -80°C in DMSO

Description:	R406 is a competitive Syk inhibitor for ATP binding with a Ki of 30 nM, potently inhibits Syk kinase activity in vitro with an IC50 of 41 nM, measured at an ATP concentration corresponding to its Km value.
In Vivo:	Prophylactic treatment of mice with R406 administers 1 h before immune complex challenge reduces the cutaneous reverse passive Arthus reaction by approximately 72 and 86% at 1 and 5 mg/kg, respectively, compared with the vehicle control. The net optical density reading of extravasated dye extracted after treatment with R406 at 1 or 5 mg/kg R406 is reduced from 0.14 (vehicle) to 0.04 or 0.02, respectively (p<0.01)[1].
In Vitro:	R406 also exhibits antagonistic activity for adenosine A3 receptor with an IC50 estimated to be 93 nM[1]. In Ramos B lymphoma cells, B-cell receptor (BCR) crosslinking induces robust phosphorylation of B-cell linker protein (BLNK), which is ablated by addition of the Syk inhibitor R406. Additionally, R406 significantly reduces constitutive Syk signaling in EBV+ cell lines derived from patients with Post-transplant lymphoproliferative disorder (PTLD), termed SLCL. Therefore, R406 inhibits Syk activation[2].