Fenton chemistry in biology and medicine

2007 ◽  
Vol 79 (12) ◽  
pp. 2325-2338 ◽  
Author(s):  
Josef Prousek
Keyword(s):  
Hydroxyl Radical ◽  
Fenton Reaction ◽  
Brown Rot ◽  
White Rot ◽  
Practical Utilization ◽  
Fenton Chemistry ◽  
Radical Production

Various aspects of the participation of Fenton chemistry in biology and medicine are reviewed. Accumulated evidence shows that both hydroxyl radical and ferryl [Fe(IV)=O]2+ can be formed under a variety of Fenton and Fenton-like reactions. Some examples of metal-independent hydroxyl radical production are included. Extracellular Fenton reaction is illustrated by the white rot and brown rot wood-decaying fungi. The natural and practical utilization of catechol-driven Fenton reaction is also presented.

scholarly journals Induction of Extracellular Hydroxyl Radical Production by White-Rot Fungi through Quinone Redox Cycling

2009 ◽  
Vol 75 (12) ◽  
pp. 3944-3953 ◽  
Author(s):  
Víctor Gómez-Toribio ◽  
Ana B. García-Martín ◽  
María J. Martínez ◽  
Ángel T. Martínez ◽  
Francisco Guillén
Keyword(s):  
Hydroxyl Radical ◽  
Fenton Reaction ◽  
White Rot Fungi ◽  
Ligninolytic Enzymes ◽  
White Rot ◽  
Oh Radicals ◽  
Production Rates ◽  
Pycnoporus Cinnabarinus ◽  
Simple Strategy ◽  
The One

ABSTRACT A simple strategy for the induction of extracellular hydroxyl radical (OH) production by white-rot fungi is presented. It involves the incubation of mycelium with quinones and Fe3+-EDTA. Succinctly, it is based on the establishment of a quinone redox cycle catalyzed by cell-bound dehydrogenase activities and the ligninolytic enzymes (laccase and peroxidases). The semiquinone intermediate produced by the ligninolytic enzymes drives OH production by a Fenton reaction (H2O2 + Fe2+ → OH + OH− + Fe3+). H2O2 production, Fe3+ reduction, and OH generation were initially demonstrated with two Pleurotus eryngii mycelia (one producing laccase and versatile peroxidase and the other producing just laccase) and four quinones, 1,4-benzoquinone (BQ), 2-methoxy-1,4-benzoquinone (MBQ), 2,6-dimethoxy-1,4-benzoquinone (DBQ), and 2-methyl-1,4-naphthoquinone (menadione [MD]). In all cases, OH radicals were linearly produced, with the highest rate obtained with MD, followed by DBQ, MBQ, and BQ. These rates correlated with both H2O2 levels and Fe3+ reduction rates observed with the four quinones. Between the two P. eryngii mycelia used, the best results were obtained with the one producing only laccase, showing higher OH production rates with added purified enzyme. The strategy was then validated in Bjerkandera adusta, Phanerochaete chrysosporium, Phlebia radiata, Pycnoporus cinnabarinus, and Trametes versicolor, also showing good correlation between OH production rates and the kinds and levels of the ligninolytic enzymes expressed by these fungi. We propose this strategy as a useful tool to study the effects of OH radicals on lignin and organopollutant degradation, as well as to improve the bioremediation potential of white-rot fungi.

scholarly journals Effect of pH and Oxalate on Hydroquinone-Derived Hydroxyl Radical Formation during Brown Rot Wood Degradation

2003 ◽  
Vol 69 (10) ◽  
pp. 6025-6031 ◽  
Author(s):  
Elisa Varela ◽  
Ming Tien
Keyword(s):  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Iron Reduction ◽  
Brown Rot ◽  
Radical Formation ◽  
Semiquinone Radical ◽  
Ferric Ion ◽  
Redox Cycle ◽  
Fenton Chemistry ◽  
Effect Of Ph

ABSTRACT The redox cycle of 2,5-dimethoxybenzoquinone (2,5-DMBQ) is proposed as a source of reducing equivalent for the regeneration of Fe2+ and H2O2 in brown rot fungal decay of wood. Oxalate has also been proposed to be the physiological iron reductant. We characterized the effect of pH and oxalate on the 2,5-DMBQ-driven Fenton chemistry and on Fe3+ reduction and oxidation. Hydroxyl radical formation was assessed by lipid peroxidation. We found that hydroquinone (2,5-DMHQ) is very stable in the absence of iron at pH 2 to 4, the pH of degraded wood. 2,5-DMHQ readily reduces Fe3+ at a rate constant of 4.5 × 103 M−1s−1 at pH 4.0. Fe2+ is also very stable at a low pH. H2O2 generation results from the autoxidation of the semiquinone radical and was observed only when 2,5-DMHQ was incubated with Fe3+. Consistent with this conclusion, lipid peroxidation occurred only in incubation mixtures containing both 2,5-DMHQ and Fe3+. Catalase and hydroxyl radical scavengers were effective inhibitors of lipid peroxidation, whereas superoxide dismutase caused no inhibition. At a low concentration of oxalate (50 μM), ferric ion reduction and lipid peroxidation are enhanced. Thus, the enhancement of both ferric ion reduction and lipid peroxidation may be due to oxalate increasing the solubility of the ferric ion. Increasing the oxalate concentration such that the oxalate/ferric ion ratio favored formation of the 2:1 and 3:1 complexes resulted in inhibition of iron reduction and lipid peroxidation. Our results confirm that hydroxyl radical formation occurs via the 2,5-DMBQ redox cycle.

Hydroxyl radical production by a heterogeneous Fenton reaction supported in insoluble tannin from bark of Pinus radiata

2016 ◽  
Vol 24 (7) ◽  
pp. 6135-6142 ◽  
Author(s):  
Romina Romero ◽  
David Contreras ◽  
Cristina Segura ◽  
Brigitte Schwederski ◽  
Wolfgang Kaim
Keyword(s):  
Hydroxyl Radical ◽  
Pinus Radiata ◽  
Fenton Reaction ◽  
Heterogeneous Fenton ◽  
Radical Production ◽  
Heterogeneous Fenton Reaction

scholarly journals Generation of *OH initiated by interaction of Fe2+ and Cu+ with dioxygen; comparison with the Fenton chemistry.

2000 ◽  
Vol 47 (4) ◽  
pp. 951-962 ◽  
Author(s):  
N K Urbański ◽  
A Beresewicz
Keyword(s):  
Superoxide Dismutase ◽  
Hydroxyl Radical ◽  
Fenton Reaction ◽  
Copper Toxicity ◽  
Reducing Agents ◽  
H2o2 Concentration ◽  
Fenton Chemistry ◽  
Fenton System ◽  
Krebs Henseleit Buffer

Iron and copper toxicity has been presumed to involve the formation of hydroxyl radical (*OH) from H2O2 in the Fenton reaction. The aim of this study was to verify that Fe2+-O2 and Cu+-O2 chemistry is capable of generating *OH in the quasi physiological environment of Krebs-Henseleit buffer (KH), and to compare the ability of the Fe2+-O2 system and of the Fenton system (Fe2+ + H2O2) to produce *OH. The addition of Fe2+ and Cu+ (0-20 microM) to KH resulted in a concentration-dependent increase in *OH formation, as measured by the salicylate method. While Fe3+ and Cu2+ (0-20 microM) did not result in *OH formation, these ions mediated significant *OH production in the presence of a number of reducing agents. The *OH yield from the reaction mediated by Fe2+ was increased by exogenous Fe3+ and Cu2+ and was prevented by the deoxygenation of the buffer and reduced by superoxide dismutase, catalase, and desferrioxamine. Addition of 1 microM, 5 microM or 10 microM Fe2+ to a range of H2O2 concentrations (the Fenton system) resulted in a H2O2-concentration-dependent rise in *OH formation. For each Fe2+ concentration tested, the *OH yield doubled when the ratio [H2O2]:[Fe2+] was raised from zero to one. (i) Fe2+-O2 and Cu+-O2 chemistry is capable of promoting *OH generation in the environment of oxygenated KH, in the absence of pre-existing superoxide and/or H2O2, and possibly through a mechanism initiated by the metal autoxidation; (ii) The process is enhanced by contaminating Fe3+ and Cu2+; (iii) In the presence of reducing agents also Fe3+ and Cu2+ promote the *OH formation; (iv) Depending on the actual [H2O2]:[Fe2+] ratio, the efficiency of the Fe2+-O2 chemistry to generate *OH is greater than or, at best, equal to that of the Fe2+-driven Fenton reaction.

scholarly journals Evidence from Serpula lacrymans that 2,5-Dimethoxyhydroquinone Is a Lignocellulolytic Agent of Divergent Brown Rot Basidiomycetes

2013 ◽  
Vol 79 (7) ◽  
pp. 2377-2383 ◽  
Author(s):  
Premsagar Korripally ◽  
Vitaliy I. Timokhin ◽  
Carl J. Houtman ◽  
Michael D. Mozuch ◽  
Kenneth E. Hammel
Keyword(s):  
Coniferous Forest ◽  
White Rot Fungi ◽  
Brown Rot ◽  
White Rot ◽  
Fenton Reagent ◽  
Fenton Chemistry ◽  
Content Type ◽  
Brown Rot Fungi ◽  
Serpula Lacrymans

ABSTRACTBasidiomycetes that cause brown rot of wood are essential biomass recyclers in coniferous forest ecosystems and a major cause of failure in wooden structures. Recent work indicates that distinct lineages of brown rot fungi have arisen independently from ligninolytic white rot ancestors via loss of lignocellulolytic enzymes. Brown rot thus proceeds without significant lignin removal, apparently beginning instead with oxidative attack on wood polymers by Fenton reagent produced when fungal hydroquinones or catechols reduce Fe3+in colonized wood. Since there is little evidence that white rot fungi produce these metabolites, one question is the extent to which independent lineages of brown rot fungi may have evolved different Fe3+reductants. Recently, the catechol variegatic acid was proposed to drive Fenton chemistry inSerpula lacrymans, a brown rot member of the Boletales (D. C. Eastwood et al., Science 333:762-765, 2011). We found no variegatic acid in wood undergoing decay byS. lacrymans. We found also that variegatic acid failed to reducein vitrothe Fe3+oxalate chelates that predominate in brown-rotting wood and that it did not drive Fenton chemistryin vitrounder physiological conditions. Instead, the decaying wood contained physiologically significant levels of 2,5-dimethoxyhydroquinone, a reductant with a demonstrated biodegradative role when wood is attacked by certain brown rot fungi in two other divergent lineages, the Gloeophyllales and Polyporales. Our results suggest that the pathway for 2,5-dimethoxyhydroquinone biosynthesis may have been present in ancestral white rot basidiomycetes but do not rule out the possibility that it appeared multiple times via convergent evolution.

scholarly journals Decomposition of spruce wood and release of volatile organic compounds depend on decay type, fungal interactions and enzyme production patterns

2019 ◽  
Vol 95 (9) ◽  
Author(s):  
Tuulia Mali ◽  
Mari Mäki ◽  
Heidi Hellén ◽  
Jussi Heinonsalo ◽  
Jaana Bäck ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Hydrolytic Enzymes ◽  
Brown Rot ◽  
White Rot ◽  
Growth Time ◽  
Fomitopsis Pinicola ◽  
Fenton Chemistry ◽  
Spruce Wood ◽  
Volatile Organic

ABSTRACT Effect of three wood-decaying fungi on decomposition of spruce wood was studied in solid-state cultivation conditions for a period of three months. Two white rot species (Trichaptum abietinum and Phlebia radiata) were challenged by a brown rot species (Fomitopsis pinicola) in varying combinations. Wood decomposition patterns as determined by mass loss, carbon to nitrogen ratio, accumulation of dissolved sugars and release of volatile organic compounds (VOCs) were observed to depend on both fungal combinations and growth time. Similar dependence of fungal species combination, either white or brown rot dominated, was observed for secreted enzyme activities on spruce wood. Fenton chemistry suggesting reduction of Fe3+ to Fe2+ was detected in the presence of F. pinicola, even in co-cultures, together with substantial degradation of wood carbohydrates and accumulation of oxalic acid. Significant correlation was perceived with two enzyme activity patterns (oxidoreductases produced by white rot fungi; hydrolytic enzymes produced by the brown rot fungus) and wood degradation efficiency. Moreover, emission of four signature VOCs clearly grouped the fungal combinations. Our results indicate that fungal decay type, either brown or white rot, determines the loss of wood mass and decomposition of polysaccharides as well as the pattern of VOCs released upon fungal growth on spruce wood.

Quinolinic acid — Iron(II) complexes: Slow autoxidation, but enhanced hydroxyl radical production in the Fenton reaction

2001 ◽  
Vol 34 (5) ◽  
pp. 445-459 ◽  
Author(s):  
Jan Pláteník ◽  
Pavel Stopka ◽  
Martin Vejražka ◽  
Stanislav Štípek
Keyword(s):  
Hydroxyl Radical ◽  
Quinolinic Acid ◽  
Fenton Reaction ◽  
Radical Production
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