R406 free base

Cas No.:	841290-80-0
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:	CC1(C(=O)NC2=C(O1)C=CC(=N2)NC3=NC(=NC=C3F)NC4=CC(=C(C(=C4)OC)OC)OC)C
Formula:	C22H23FN6O5
M.Wt:	470.45
Sotrage:	2 years -20°C Powder, 2 weeks 4°C in DMSO, 6 months -80°C in DMSO

Description:	R406 is a potent Syk inhibitor with IC50 of 41 nM, strongly inhibits Syk but not Lyn, 5-fold less potent to Flt3.
In Vivo:	R406 reduces cutaneous reverse passive Arthus reaction by approximately 86% at 5 mg/kg in prophylactic treated mice. R406 also shows efficacy in inhibiting paw inflammation in antibody-induced arthritis mouse models [1]. R406 does not adversely affect macrophage or neutrophil function in innate immune responses and has minimal functional immunotoxicity notwithstanding its lymphocytopenic effect [4].
In Vitro:	R406 is a potent inhibitor of immunoglobulin E (IgE)- and IgG-mediated activation of Fc receptor signaling. R406 inhibits the anti-IgE-induced production and release of LTC4 and cytokines and chemokines, including TNFα, IL-8, and GM-CSF. R406 inhibits phosphorylation of Syk substrate linker for activation of T cells in mast cells and B-cell linker protein/SLP65 in B cells. R406 binds to the ATP binding pocket of Syk and inhibits its kinase activity as an ATP-competitive inhibitor with Ki of 30 nM. R406 blocks Syk-dependent FcR-mediated activation of monocytes/macrophages and neutrophils and Bcr-mediated activation of B lymphocytes [1]. R406 significantly induces chronic lymphocytic leukemia (CLL) cell apoptosis in nurselike cells cocultures and blocks CCL3 and CCL4 secretion by CLL cells in response to B-cell antigen receptor (Bcr) triggering [2]. R406 is a potent inhibitor of platelet signaling and functions initiated by FcγRIIA cross-linking by specific antibodies or by sera from HIT patients [3].