Chromogenic and neurotoxic effects of an aliphatic γ-diketone

Computational insights into the molecular structures and mechanism

Chang Guo Zhan, Peter Spencer, David A. Dixon

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

First-principles electronic structure calculations have been performed to predict chromogenic properties of various candidate structures, including pyrrole monomers and dimers and their derivatives, of the chromophores formed from the reactions of 2,5-hexanedione (2,5-HD), a prototype of neurotoxic aliphatic γ-diketones, with NH 3, amino acids, and proteins. The calculated results indicate that the pyrrole monomer structures and a previously proposed dimer structure do not have an absorption in the visible region (A > ∼400 nm and <∼700 nm), whereas a novel type of pyrrole dimer structure has absorptions (γ = ∼400 to 420 nm) in the visible region if the methyl (CH 3) groups on the pyrrole rings are oxidized to CHO groups. The calculated results for the oxidized pyrrole dimer models for cross-linked proteins are consistent with all of the available experimental data for the chromogenic and neurotoxic effects of 2,5-HD. Our results strongly support the conclusion that the chromogenic effects of aliphatic γ-diketones are closely related to their neurotoxic effects and further predict that both the chromogenic and neurotoxic effects are associated with the same chemical reaction process. Such a reaction process most likely starts from the formation of the pyrrole-protein adducts followed by dimerization and further oxidization.

Original languageEnglish (US)
Pages (from-to)6098-6104
Number of pages7
JournalJournal of Physical Chemistry B
Volume108
Issue number19
StatePublished - May 13 2004

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Chromogenics
Pyrroles
pyrroles
Dimers
Molecular structure
molecular structure
Proteins
dimers
Monomers
proteins
Dimerization
Chromophores
monomers
Electronic structure
Amino acids
Chemical reactions
dimerization
Derivatives
chromophores
adducts

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Chromogenic and neurotoxic effects of an aliphatic γ-diketone : Computational insights into the molecular structures and mechanism. / Zhan, Chang Guo; Spencer, Peter; Dixon, David A.

In: Journal of Physical Chemistry B, Vol. 108, No. 19, 13.05.2004, p. 6098-6104.

Research output: Contribution to journalArticle

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