CNDO/2 quantum-mechanical calculations of the conformational flexibility of the diketopiperazine skeleton

✍ Scribed by Jerzy Ciarkowski

• Publisher: Wiley (John Wiley & Sons)
• Year: 1984
• Tongue: English
• Weight: 549 KB
• Volume: 23
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360230303

✦ Synopsis

Eight conformers typical of diketopiperazine (DKP) ring folding were chosen for analysis.

Conf~ormational energy calculations were carried out using the semiempirical quantummechanical CNDOI:! method. The results obtained confirm considerable flexibility of'the IIKP skeleton. As the degree of' folding increases, twisted boat conformations with the nonplanar peptide bonds tend to he more stable, while more rigid regular boat conformations with planar peptide bonds appear to be less stable than a flat one. The CNDOD method was found to he reliable enough for conformational studies of cyclic peptide skeletons with cispeptide bonds.