PT  - JOURNAL ARTICLE
AU  - MICHIO MOTOHASHI
AU  - MASAO NISHIKAWA
TI  - Conformational Analysis of <em>Beta</em><sub>2</sub>-Adrenoceptor-Stimulating Agents
DP  - 1981 Jul 01
TA  - Molecular Pharmacology
PG  - 22--27
VI  - 20
IP  - 1
4099  - http://molpharm.aspetjournals.org/content/20/1/22.short
4100  - http://molpharm.aspetjournals.org/content/20/1/22.full
SO  - Mol Pharmacol1981 Jul 01; 20
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.