Determination of long‐range 13C, 1H coupling constants of macrolide antibiotics by 2D J—δ selective INEPT experiments

Abstract

Abstract2D J—δ selective INEPT experiments were used to measure long‐range 13C,1H coupling constants for the macrolide antibiotics roxithromycin, erythromycin and their metabolites, RU 39001 and erythralosamine, respectively. The 2D J—δ selective INEPT experiment was performed using selective excitation by a DANTE pulse train. In some cases, to avoid truncation problems in the t1 domain, treatment of the data using a linear prediction method was adopted. Dihedral angles for the glycosidic bonds and the erythronolid unit were deduced from a Karplus‐type equation for conformational study. The apparent equilibrium between different conformers is discussed by comparison of experimental results and theoretical calculations by molecular dynamics.