title: Structure-activity relationships in further series of amino-halogen substituted phenyl-aminoethanols.
abstract: Series of 1-(4-amino-phenyl)-2-aminoethanol derivatives having different substituents in the phenyl nucleus were compared with 1-(4-amino-3,5-dichloro-phenyl)-2-tert.-butylamino-ethanol (clenbuterol) with regard to their action on the adrenergic beta-receptors of guinea pigs, cats and rats. The exchange of the two chlorine atoms of clenbuterol led to substances with a potent beta 2-mimetic activity, surpassing that of clenbuterol, in the bronchial muscles and/or to a beta 1-blocking action in the heart with a relatively low beta 1-intrinsic activity. The strongest action was found with the chloro-cyano, fluoro-cyano and mono-cyano substituted compounds. The chloro-fluoro, bromo-fluoro, mono-fluoro and chloro-trifluoromethyl substituted compounds showed a good oral absorption, comparable to that of clenbuterol. Because of a particularly low beta 1-intrinsic activity in the heart with a long-lasting beta 2-mimetic action on the bronchial muscles also after oral administration, the 1-(4-amino-3-chloro-5-trifluoromethyl-phenyl)-2-tert.-butylamino-ethanol hydrochloride (mabuterol) must come of all the structures investigated particularly into consideration as broncholytic agent for therapeutic use.
mesh_terms: D000318:Adrenergic beta-Agonists / Q000138:chemical synthesis* / Q000494:pharmacology; D000818:Animals; D001985:Bronchial Provocation Tests; D001993:Bronchodilator Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D002415:Cats; D002976:Clenbuterol / Q000031:analogs & derivatives / Q000494:pharmacology; D004983:Ethanolamines / Q000138:chemical synthesis* / Q000494:pharmacology; D005260:Female; D006003:Glycogen / Q000378:metabolism; D006168:Guinea Pigs; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000037:antagonists & inhibitors; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship
chemical_list: D000318:Adrenergic beta-Agonists; D001993:Bronchodilator Agents; D004983:Ethanolamines; D006003:Glycogen; D007545:Isoproterenol; C044573:mabuterol; D002976:Clenbuterol