Application of cultured human mast cells (CHMC) for the design and structure–activity relationship of IgE-mediated mast cell activation inhibitors

[Display omitted] Here we report the optimization of small molecule inhibitors of human mast cell degranulation via anti-IgE-mediated tryptase release following cross-linking and activation of IgE-loaded FcεR1 receptors. The compounds are selective upstream inhibitors of FcεR1-dependent human mast cell degranulation and proved to be devoid of activity in downstream ionomycin mediated degranulation. Structure–activity relationship (SAR) leading to compound 26 is outlined.