AN NMR STUDY OF EREMOMYCIN AND ITS DERIVATIVES

FULL ¹H AND ¹³C ASSIGNMENT, MOTIONAL BEHAVIOR, DIMERIZATION AND COMPLEXATION WITH AC-D-ALA-D-ALA

Abstract

Complete ¹H and ¹³C NMR assignments are presented for eremomycin (1) and some of its desglycosylated derivatives 2, 3 and compared to the structurally closely related glycopeptide vancomycin. Primary structure and stereochemistry of eremomycin is corroborated by the present high field total correlation spectroscopy, NOESY and heteronuclear multiple-bond correlation NMR methods. A rough motional characterization of the title compound is attempted by ¹³C-T₁ and ¹³C-{¹H} NOE measurements. Dimerization of eremomycin is observed both in DMSO-d₆-CCl₄ and D₂O solutions. Complexation with cell wall analogue dipeptide Ac-D-Ala-D-Ala is also demonstrated.