1H and 13C NMR conformational analysis in solution of isoproterenol a pure β-agonist drug

13C and 1H NMR parameters were measured for isoproterenol in solution. Spin-lattice relaxation rates were considered and C-H and H-H J couplings were determined. The t rotamer was shown to occur in a much greater abundance than the two g rotamers. Dynamics in solution were interpreted in terms of a nearly isotropic motion of the α-hydroxyphenethyl moiety and of a high degree of flexibility of the isopropyl moiety, Relevant distances and dipolar connectivities were measured and used to build up a Dreiding model of the most probable conformation.