Hybrids consisting of the pharmacophores of salmeterol and roflumilast or phthalazinone: Dual β2-adrenoceptor agonists-PDE4 inhibitors for the treatment of COPD

A novel class of dual pharmacology bronchodilators targeting both β2-adrenoceptor and PDE4 was designed and synthesised by combining the pharmacophores of salmeterol and roflumilast or phthalazinone. All the compounds exhibited better β2-adrenoceptor agonist activities (pEC50 = 8.47-9.20) than the reference compound salmeterol (pEC50 = 8.3) and good inhibitory activities on PDE4B2 (IC50 = 0.235-1.093 μM).