Conformational studies of bacterial peptidoglycan: structure and stereochemistry of N-acetyl-β-d-glucosamine and N-acetyl-β-d-muramic acid

Abstract

The energies of various conformations of N-acetyl-β-d-glucosamine (NAG) and its 3-O-d-lactic acid derivative N-acetyl-β-d-muramic acid (NAM) have been calculated by geometry optimization using the molecular mechanics program MM2. The geometries of these systems have been analyzed in the light of ring torsion, bond lengths, bond angles and conformational states of side groups of the pyranosyl ring and compared with available experimental data of similar pyranose derivatives. The present study indicates the presence of hydrogen bonds to stabilize the side group conformations. Discrepancies with experimental data that are seen in a few cases are ascribed to the nature of the side groups and their geometry. © 1989.