Open AccessA DFT Study of the cis-Dihydroxylation of Nitroaromatic Compounds Catalyzed by Nitrobenzene Dioxygenase
Author(s) -
Anna Pabis,
Inacrist Geronimo,
Piotr Paneth
Publication year - 2014
Publication title -
the journal of physical chemistry. b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 392
eISSN - 1520-6106
pISSN - 1520-5207
DOI - 10.1021/jp4076299
Subject(s) - dihydroxylation , dioxygenase , nitrobenzene , chemistry , catalysis , hydroxylation , substrate (aquarium) , ferredoxin , stereochemistry , ring (chemistry) , photochemistry , reaction mechanism , medicinal chemistry , enzyme , organic chemistry , enantioselective synthesis , oceanography , geology
The mechanism of cis-dihydroxylation of nitrobenzene and 2-nitrotoluene catalyzed by nitrobenzene 1,2-dioxygenase (NBDO), a member of the naphthalene family of Rieske non-heme iron dioxygenases, was studied by means of the density functional theory method using four models of the enzyme active site. Different possible reaction pathways for the substrate dioxygenation initiated either by the Fe(III)-OOH or HO-Fe(V)═O attack on the aromatic ring were considered and the computed activation barriers compared with the Gibbs free energy of activation for the oxygen-oxygen cleavage leading to the formation of the iron(V)-oxo species from its ferric hydroperoxo precursor. The mechanism of the substrate cis-dihydroxylation leading to the formation of a cis-dihydrodiol was then investigated, and the most feasible mechanism was found to be starting with the attack of the high-valent iron-oxo species on the substrate ring yielding a radical intermediate, which further evolves toward the final product.