Elucidation of the catalytic mechanisms of the non-haem iron-dependent catechol dioxygenases: synthesis of carba-analogues for hydroperoxide reaction intermediates

Winfield, Christopher J.; Al-Mahrizy, Zeyana; Gravestock, Michael B.; Bugg, Timothy D. H.

doi:10.1039/b004265j

Cited by 46 publications

(32 citation statements)

References 25 publications

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“…had proposed that the increased Lewis acidity of the ferric center enhances the covalency of the metal‐catecholate interaction and the semiquinone character of the bound catecholate, thereby activating the catecholate for reaction with O 2. Further, when dioxygen attacks the activated carbon atom of catecholate substrate strongly bound to the iron(III) center in the adduct (substrate‐activation mechanism), the Criegee intermediate [(L)(DBSQ)Fe(III)O 2 ] − gives intradiol cleavage products upon acyl migration and extradiol cleavage products upon alkenyl migration …”

Section: Resultsmentioning

confidence: 99%

An Oxido‐Bridged Diiron(II) Complex as Functional Model of Catechol Dioxygenase

Dey¹,

De²,

Yadav

et al. 2016

ChemistrySelect

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An oxido-bridged diiron(II)-phenanthroline complex, [Fe 2 O(phen) 2 Cl 2 ] (1) [phen = 1,10-phenanthroline] has been synthesized from an oxido-bridged diiron(III) precursor in presence of sodium azide and structurally characterized by different spectroscopic tools including single crystal X-ray diffraction study.-From X-ray crystal structure of 1, it is revealed that each of the Fe(II) centre is in distorted octahedral geometry with FeN 4 OCl core and the molecule crystallizes in Pnc2 space group. Bond valence sum (BVS) calculation confirms the existence of iron ions in + 2 oxidation state in 1. The diiron(II) complex has been evaluated as model system for the catechol dioxygenase enzyme by using 3,5-di-tert-butylcatechol (DTBC) as the substrate in acetonitrile medium, revealing that 1 efficiently mimics the catalytic cycle of catechol dioxygenase. Upon stoichiometric addition of DTBC pretreated with two equivalents of triethylamine (Et 3 N) to the diiron complex, two catecholate-to-iron(III) LMCT bands (515 nm and 734 nm) are observed. The in situgenerated catecholate adduct from 1in acetonitrile solution react with dioxygen to afford exclusively extradiol cleavage products along with a small amount of benzoquinone, which is also discerned from the appearance and decrease in intensity of the electronic spectral bands around (708 nm; 507 nm) nm. Nucleophilic attack by molecular oxygen on catecholate adduct in solution provides substantial evidence for the regioselective extradiol cleavage products.

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Section: Resultsmentioning

confidence: 99%

An Oxido‐Bridged Diiron(II) Complex as Functional Model of Catechol Dioxygenase

Dey¹,

De²,

Yadav

et al. 2016

ChemistrySelect

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“…There are no published inhibitors for protocatechuate 3,4-dioxygenase, and the only previously published extradiol catechol dioxygenase inhibitors are reaction intermediate analogues prepared for E. coli MhpB that showed K i values of 0.7-7.6 mM [21]. Iron-chelating inhibitors have been prepared for other non-haem iron-dependent enzymes such as mammalian p-hydroxyphenylpropionate dioxygenase [22] and 2-oxoglutarate dioxygenases such as human PHD2 [23].…”

Section: Discussionmentioning

confidence: 98%

Chemical intervention in bacterial lignin degradation pathways: Development of selective inhibitors for intradiol and extradiol catechol dioxygenases

Sainsbury

Mineyeva

Mycroft

et al. 2015

Bioorganic Chemistry

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“…The structures of extradiol catecholdioxygenases indicated that the distal peroxy intermediate is hard to be formed without a drastic motion of the catechol substrate in the active site because of its highly constrained conformation [11,12]. By using carba-analogs of the proximal and distal peroxy intermediates as inhibitors, Bugg and co-workers elegantly demonstrated that the proximal peroxy intermediate is involved in the reaction mechanism of extradiol enzymes, similarly to intradiol enzymes [1,14,15]. However, further investigations are necessary to clarify how the regioselective oxygen insertion can take place through the common proximal peroxy intermediate.…”

Section: Introductionmentioning

confidence: 99%