RT Journal Article SR Electronic T1 Conformational Analysis of Beta2-Adrenoceptor-Stimulating Agents JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 22 OP 27 VO 20 IS 1 A1 MOTOHASHI, MICHIO A1 NISHIKAWA, MASAO YR 1981 UL http://molpharm.aspetjournals.org/content/20/1/22.abstract AB The conformation of 2-cyclobutylamino-5,6-dihydroxy-1,2,3,4-tetrahydro-1-naphthalenol, a very potent beta-adrenoceptor-stimulating agent, was analyzed in solution by proton relaxation techniques. This compound seems to take two equilibrium conformations, one of which corresponds to that of the crystalline state. Furthermore, the conformational analysis of isoetharine and several beta2-adrenergic-stimulating agents made it possible to restrict three dihedral angles so that the molecule was beta2-active. Restricting these three dihedral angles unequivocally settles the stereochemical arrangement of all functional groups involved in beta2-stimulants, two catechol hydroxyls, benzylic hydroxyl, and two N+-H bonds. ACKNOWLEDGMENTS The authors are grateful to Drs. E. Ohmura, K. Morita, and Y. Sanno for encouragement and helpful advice throughout this study.