Predicting cyclic peptide chemical shifts using quantum mechanical calculations

A hybrid sequential molecular mechanics and quantum mechanical approach to modeling cyclic peptides has led to an effective method for predicting their H-1 and C-13 NMR chemical shift values. The method was first developed to predict chemical shifts in chloroform before being adapted to a more peptide friendly solvent, DMSO. Finally the effectiveness of this method was tested in a blind fashion and excellent agreement with the experimental NMR chemical shifts was observed. (C) 2014 Elsevier Ltd. All rights reserved.