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Wyszukujesz frazę "nitroaromatic compounds" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Reduction of nitroaromatic compounds by NAD(P)H:quinone oxidoreductase (NQO1): the role of electron-accepting potency and structural parameters in the substrate specificity
Autorzy:
Misevičienė, Lina
Anusevičius, Žilvinas
Šarlauskas, Jonas
Čėnas, Narimantas
Powiązania:
https://bibliotekanauki.pl/articles/1041217.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
reduction potential
DT-diaphorase
nitroaromatic compounds
reduction mechanism
explosives
Opis:
We aimed to elucidate the role of electronic and structural parameters of nitroaromatic compounds in their two-electron reduction by NAD(P)H:quinone oxidoreductase (NQO1, DT-diaphorase, EC 1.6.99.2). The multiparameter regression analysis shows that the reactivity of nitroaromatic compounds (n = 38) increases with an increase in their single-electron reduction potential and the torsion angle between nitrogroup(s) and the aromatic ring. The binding efficiency of nitroaromatics in the active center of NQO1 exerted a less evident role in their reactivity. The reduction of nitroaromatics is characterized by more positive entropies of activation than the reduction of quinones. This points to a less efficient electronic coupling of nitroaromatics with the reduced isoalloxazine ring of FAD, and may explain their lower reactivity as compared to quinones. Another important but poorly understood factor enhancing the reactivity of nitroaromatics is their ability to bind at the dicumarol/quinone binding site in the active center of NQO1.
Źródło:
Acta Biochimica Polonica; 2006, 53, 3; 569-576
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Single-electron reduction of quinone and nitroaromatic xenobiotics by recombinant rat neuronal nitric oxide synthase
Autorzy:
Anusevičius, Žilvinas
Nivinskas, Henrikas
Šarlauskas, Jonas
Sari, Marie-Agnes
Boucher, Jean-Luc
Čėnas, Narimantas
Powiązania:
https://bibliotekanauki.pl/articles/1039577.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
antitumour agents
nitroaromatic compounds
electron transfer mechanism
oxidative stress
quinones
Neuronal nitric oxide synthase (nNOS)
Opis:
We examined the kinetics of single-electron reduction of a large number of structurally diverse quinones and nitroaromatic compounds, including a number of antitumour and antiparasitic drugs, and nitroaromatic explosives by recombinant rat neuronal nitric oxide synthase (nNOS, EC 1.14.13.39), aiming to characterize the role of nNOS in the oxidative stress-type cytotoxicity of the above compounds. The steady-state second-order rate constants (kcat/Km) of reduction of the quinones and nitroaromatics varied from 102 M-1s-1 to 106 M-1s-1, and increased with an increase in their single-electron reduction potentials (E17). The presence of Ca2+/calmodulin enhanced the reactivity of nNOS. These reactions were consistent with an 'outer sphere' electron-transfer mechanism, considering the FMNH./FMNH2 couple of nNOS as the most reactive reduced enzyme form. An analysis of the reactions of nNOS within the 'outer sphere' electron-transfer mechanism gave the approximate values of the distance of electron transfer, 0.39-0.47 nm, which are consistent with the crystal structure of the reductase domain of nNOS. On the other hand, at low oxygen concentrations ([O2] = 40-50 μM), nNOS performs a net two-electron reduction of quinones and nitroaromatics. This implies that NOS may in part be responsible for the bioreductive alkylation by two-electron reduced forms of antitumour aziridinyl-substituted quinones under a modest hypoxia.
Źródło:
Acta Biochimica Polonica; 2013, 60, 2; 217-222
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of the Condensed Phase Enthalpy of Formation of Nitroaromatic Compounds Using the Estimated Gas Phase Enthalpies of Formation by the PM3 and B3LYP Methods
Autorzy:
Oftadeh, M.
Keshavarz, M. H.
Khodadadi, R.
Powiązania:
https://bibliotekanauki.pl/articles/951504.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
condensed phase enthalpy formation
gas phase enthalpy formation
nitroaromatic compounds
PM3
B3LYP
Opis:
A new method is introduced to correlate the condensed phase enthalpies of formation of nitroaromatic compounds with their gas phase enthalpies of formation on the basis of the B3LYP/6-31G* and PM3 methods. For the B3LYP method, the condensed phase enthalpy of formation depends on the number of certain elements, nitro groups and aromatic rings. For the PM3 method the number of N=N or N≡N groups, and the presence or absence of three interconnected rings, in addition to some of the parameters mentioned above, are necessary in order to obtain a reliable correlation. For 72 nitroaromatic compounds, the calculated root mean square (rms) deviations of the condensed phase enthalpies of formation of nitroaromatic compounds using the B3LYP and PM3 methods are 63.63 and 32.17 kJ/mol, respectively. The results predicted on the basis of the PM3 method are compared with the best available experimental data.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 1; 143-156
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quinone- and nitroreductase reactions of Thermotoga maritima thioredoxin reductase
Autorzy:
Valiauga, Benjaminas
Rouhier, Nicolas
Jacquot, Jean-Pierre
Čėnas, Narimantas
Powiązania:
https://bibliotekanauki.pl/articles/1039108.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
thioredoxin reductase
quinones
nitroaromatic compounds
oxidative stress
Thermotoga
Opis:
The Thermotoga maritima NADH:thioredoxin reductase (TmTR) contains FAD and a catalytic disulfide in the active center, and uses a relatively poorly studied physiological oxidant Grx-1-type glutaredoxin. In order to further assess the redox properties of TmTR, we used series of quinoidal and nitroaromatic oxidants with a wide range of single-electron reduction potentials (E17, -0.49-0.09 V). We found that TmTR catalyzed the mixed single- and two-electron reduction of quinones and nitroaromatic compounds, which was much faster than the reduction of Grx-1. The reactivity of both groups of oxidants increased with an increase in their E17, thus pointing to the absence of their structural specificity. The maximal rates of quinone reduction in the steady-state reactions were lower than the maximal rates of reduction of FAD by NADH, obtained in presteady-state experiments. The mixed-type reaction inhibition by NAD+ was consistent with its competition for a NADH binding site in the oxidized enzyme form, and also with the reoxidation of the reduced enzyme form. The inhibition data yielded a value of the standard potential for TmTR of -0.31±0.03 V at pH 7.0, which may correspond to the FAD/FADH2 redox couple. Overall, the mechanism of quinone- and nitroreductase reactions of T. maritima TR was similar to the previously described mechanism of Arabidopsis thaliana TR, and points to their prooxidant and possibly cytotoxic role.
Źródło:
Acta Biochimica Polonica; 2015, 62, 2; 303-309
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Relationship between Impact Sensitivity of Nitroaromatic Energetic Compounds and their Electrostatic Sensitivity
Autorzy:
Zohari, N.
Seyed-Sadjadi, S. A.
Marashi-Manesh, S.
Powiązania:
https://bibliotekanauki.pl/articles/358443.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic materials
nitroaromatic compounds
impact sensitivity
electrostatic sensitivity
safety
Opis:
This study presents a linear relationship between the impact sensitivity of nitroaromatic energetic compounds and their electric spark sensitivity. The methodology assumes that the impact sensitivity of a nitroaromatic energetic compound with the general formula CaHbNcOd can be expressed as a function of the electrostatic sensitivity, the number of NH2 group substitutions in the 2,4,6-trinitrophenyl ring and non-additive structural parameters. The root mean square and absolute standard deviation of a newly introduced correlation were respectively found to be 2.4 and 2.0 for 27 nitroaromatic energetic compounds. The proposed new correlation was also tested for 7 additional nitroaromatic energetic compounds, which have complex molecular structures such as 1-(2,4,6-trinitrophenyl)-5,7-dinitrobenzotriazole and 1,3,7,9-tetranitrophenoxazine.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 2; 427-443
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biodegradation of 3,5-dinitrosalicylic acid by Phanerochaete chrysosporium
Autorzy:
Madaj, Rafał
Kalinowska, Halina
Sroczyński, Witold
Szeląg, Jakub
Sobiecka, Elżbieta
Powiązania:
https://bibliotekanauki.pl/articles/764850.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
nitroaromatic compounds
white-rot fungi
fungal biodegradation
Opis:
Związki nitrowe to szeroka grupa ksenobiotyków, które ze względu na swoją silną toksyczność, wyjątkową odporność na rozkład biologiczny oraz skłonność do bioakumulacji, stanowią bardzo poważny problem dla biosfery. Prowadzi się obecnie wiele badań nad mikroorganizmami, które zdołały wykształcić szlaki metaboliczne pozwalające na rozkład takich związków jak 2,4,6-trinitrotoluen, kwas pikrynowy czy kwas 3,5-dinitrosalicylowy. Jednym z takich mikroorganizmów jest podstawczak Phanerochaete chrysosporium, należący do grupy grzybów białej zgnilizny drewna. Artykuł ten poświęcony jest badaniom nad rozkładem kwasu 3,5-dinitrosalicylowego przez P. chrysosporium w warunkach hodowli stacjonarnej w pożywce zawierającej 0,05–0,5% masowego kwasu 3,5-dinitrosalicylowego. Uzyskane wyniki wskazują na zdolność wybranego mikroorganizmu do rozkładu substratu na drodze redukcji grup nitrowych.
Despite intensive efforts put on prevention of environment pollution by nitroaromatic compounds, these xenobiotics have not been eliminated from the biosphere. The physicochemical properties make nitroaromatics extremely recalcitrant to biodegradation. Therefore, microbial degraders of these pollutants are sought after. This paper reports preliminary results of the study on degradation of 3,5-dinitrosalicylic acid (DNS) by a basidiomycetous fungus Phanerochaete chrysosporium under stationary conditions in a culture medium containing 0.05–0.5% v/v of DNS. The results obtained suggest that the fungus degrades DNS through the reductive pathway.
Źródło:
Acta Universitatis Lodziensis. Folia Biologica et Oecologica; 2018, 14; 14-22
1730-2366
2083-8484
Pojawia się w:
Acta Universitatis Lodziensis. Folia Biologica et Oecologica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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