β1- and β2-adrenoceptor antagonist activity of a series of para- substituted N-isopropylphenoxypropanolamines

Abstract

To further explore the structure-activity relationships of β- adrenoceptor (β-AR) antagonists, a series of 25 para-substituted N- isopropylphenoxy-propanolamines were synthesised, nine of which are new compounds. All have been examined for their ability to antagonise β1-ARs in rat atria and β2-ARs in rat trachea. Substitution in the para-position of the phenyl ring is thought to confer β3-specificity and the selectivity of these compounds for the β1-AR ranges from 1.5-234. None of the compounds tested were selective for the β2-AR. Of the 25 compounds studied, 22 had reasonable (pA2 > 7) potencies for the rat β1-AR. Only compound 1 displayed reasonable (pA2 > 7) potency for the rat β2-AR. Twe..