New transient receptor potential TRPV1, TRPM8 and TRPA1 channel antagonists from a single linear β,γ-diamino ester scaffold†
A high throughput screening campaign identified nine β,γ-diamino ester derivatives as TRP modulators. A discrete library of new derivatives (23 components) was prepared in a one-pot two step reductive amination reaction, and evaluated for their ability to block the agonist-induced calcium influx in cells expressing human TRPV1, TRPM8 and TRPA1 channels. Selective antagonists for each channel, as well as dual TRPV1/TRPM8 and TRPM8/TRPA1 ligands, were obtained after subtle modification of this linear scaffold. SAR studies revealed the preferred substituents for the selective blockade of the three TRP channels under study. The most potent TRPV1 antagonists displayed submicromolar IC50 values.