Conformational studies of N-acetyl-N′-methylamide derivatives of α-aminobutyric acid, norvaline, and valine. II. Conformational energy calculations and comparison with experimental results

✍ Scribed by Akihiro Abe; Toshimasa Yamazaki

• Publisher: Wiley (John Wiley & Sons)
• Year: 1988
• Tongue: English
• Weight: 840 KB
• Volume: 27
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360270608

✦ Synopsis

Conformational analyses on a series of dipeptides CH,-C*O-NH-CH(R) -C*O-HN-CH, with side chains such as R = CH2CH3,.CH,CH,CH,, and CH(CH,), are described. Calculations were carried out by using semiempirical potential energy functions of Brant et al. The results were compared with those reported by Vhquez et al. and Chuman et al., who employed the ECEPP program in their analyses. The averages of the vicinal coupling constant JNH--CmH and the side-chain conformer fractions p(xl) and p(x2)' were estimated therefrom for preferred conformations. The characteristic features of the experimental observations derived from the 'H-nmr measurements are reasonably well reproduced by these calculations.