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Calculations on the low energy conformers of N-acetyl-D-alanyl-D-alanine

✍ Scribed by J. Frau; J. Donoso; F. Muñoz; F. García Blanco

Publisher: Wiley (John Wiley & Sons)
Year: 1998
Tongue: English
Weight: 226 KB
Volume: 45
Category: Article
ISSN: 0006-3525
DOI: 10.1002/(sici)1097-0282(199802)45:2<119::aid-bip3>3.0.co;2-v

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✦ Synopsis

In this article a conformational analysis of the D-alanyl-D-alanine dipeptide, both charged and neutral, has been carried out. The preferred conformations were determined by means of ab initio and semiempirical quantum, together with empirical force field calculations. The AMBER* force field and the 6-31 / G** and 6-31G** ab initio levels give rise to a coincident minimum energy structure, which, on the other hand, differs from that determined by AM1, 3-21 / G, and 3-21G. The solvent effect on the different charged and neutral conformations have been considered through the AMSOL semiempirical method. A quantification regarding the structural similarities between the different dipeptide conformations and the ampicillin has been performed. The results show that the best overlay is attained by the minimum structure energy obtained by using the 6-31 / G** methodology, which presents a planar amidic nitrogen.

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