TY - JOUR T1 - Conformational Analysis of <em>Beta</em><sub>2</sub>-Adrenoceptor-Stimulating Agents JF - Molecular Pharmacology JO - Mol Pharmacol SP - 22 LP - 27 VL - 20 IS - 1 AU - MICHIO MOTOHASHI AU - MASAO NISHIKAWA Y1 - 1981/07/01 UR - http://molpharm.aspetjournals.org/content/20/1/22.abstract N2 - 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. ER -