R 112 (pharMaceutical)

R112 is an inhibitor of spleen tyrosine kinase (Syk; IC₅₀ = 226 nM in cultured human mast cells) that acts in an ATP-competitive and reversible manner (K_i = 96 nM). It inhibits mast cell and basophil degranulation induced by anti-IgE cross-linking (EC₅₀s = 353 and 280 nM, respectively). It also inhibits basophil degranulation induced by an allergen with an EC₅₀ value of 490 nM. R112 inhibits the production of leukotriene C₄ (LTC₄; ) and decreases cytokine levels in cultured human mast cells.

R 112 is Syk inhibitor. It can be used in biological study and therapeutic use of application of cultured human mast cells (CHMC) for design and structure-activity relationship of IgE-mediated mast cell activation inhibitors.

[1] ALEXANDER B. ROSSI BA. Identification of the Syk kinase inhibitor R112 by a human mast cell screen[J]. Journal of Allergy and Clinical Immunology, 2006, 118 3: Pages 749-755. DOI: 10.1016/j.jaci.2006.05.023