Journal articles: 'Nitration'

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Arasimowicz-Jelonek, Magdalena, and Jolanta Floryszak-Wieczorek. "A physiological perspective on targets of nitration in NO-based signaling networks in plants." Journal of Experimental Botany 70, no. 17 (July 25, 2019): 4379–89. http://dx.doi.org/10.1093/jxb/erz300.

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Abstract Although peroxynitrite (ONOO−) has been well documented as a nitrating cognate of nitric oxide (NO) in plant cells, modifications of proteins, fatty acids, and nucleotides by nitration are relatively under-explored topics in plant NO research. As a result, they are seen mainly as hallmarks of redox processes or as markers of nitro-oxidative stress under unfavorable conditions, similar to those observed in human and other animal systems. Protein tyrosine nitration is the best-known nitrative modification in the plant system and can be promoted by the action of both ONOO− and related NO-derived oxidants within the cell environment. Recent progress in ‘omics’ and modeling tools have provided novel biochemical insights into the physiological and pathophysiological fate of nitrated proteins. The nitration process can be specifically involved in various cell regulatory mechanisms that control redox signaling via nitrated cGMP or nitrated fatty acids. In addition, there is evidence to suggest that nitrative modifications of nucleotides embedded in DNA and RNA can be considered as smart switches of gene expression that fine-tune adaptive cellular responses to stress. This review highlights recent advances in our understanding of the potential implications of biotargets in the regulation of intracellular traffic and plant biological processes.

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Fujisawa, Yasuko, Kazunobu Kato, and Cecilia Giulivi. "Nitration of tyrosine residues 368 and 345 in the β-subunit elicits FoF1-ATPase activity loss." Biochemical Journal 423, no. 2 (September 25, 2009): 219–31. http://dx.doi.org/10.1042/bj20090594.

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Tyrosine nitration is a covalent post-translational protein modification associated with various diseases related to oxidative/nitrative stress. A role for nitration of tyrosine in protein inactivation has been proposed; however, few studies have established a direct link between this modification and loss of protein function. In the present study, we determined the effect of nitration of Tyr345 and Tyr368 in the β-subunit of the F1-ATPase using site-directed mutagenesis. Nitration of the β-subunit, achieved by using TNM (tetranitromethane), resulted in 66% ATPase activity loss. This treatment resulted in the modification of several asparagine, methionine and tyrosine residues. However, nitrated tyrosine and ATPase inactivation were decreased in reconstituted F1 with Y368F (54%), Y345F (28%) and Y345,368F (1%) β-subunits, indicating a clear link between nitration at these positions and activity loss, regardless of the presence of other modifications. Kinetic studies indicated that an F1 with one nitrated tyrosine residue (Tyr345 or Tyr368) or two Tyr368 residues was sufficient to grant inactivation. Tyr368 was four times more reactive to nitration due to its lower pKa. Inactivation was attributed mainly to steric hindrance caused by adding a bulky residue more than the presence of a charged group or change in the phenolic pKa due to the introduction of a nitro group. Nitration at this residue would be more relevant under conditions of low nitrative stress. Conversely, at high nitrative stress conditions, both tyrosine residues would contribute equally to ATPase inactivation.

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Chikina, Maya V., Daria A. Kulagina, and Sergey V. Sysolyatin. "Nitration of 2,6,8,12-Tetraacetyl-2,4,6,8,10,12-Hexaazaisowurtzitane Derivatives." Materials 15, no. 22 (November 8, 2022): 7880. http://dx.doi.org/10.3390/ma15227880.

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The nitration of novel bioactive derivatives of 2,6,8,12-tetraacetyl-2,4,6,8,10,12-hexaazaisowurtzitane in different nitrating systems was examined. The yield of CL-20, the known product from the nitration of hexaazaisowurtzitane compounds, was found to depend on the nature of substituents at the 4,1 positions and on the composition of the nitrating mixture.

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Li, Bin Dong, Jian Wu, and Xiao Ming Ma. "Study on the Green Nitration of Toluene in a Microglass Reactor." Advanced Materials Research 396-398 (November 2011): 2018–22. http://dx.doi.org/10.4028/www.scientific.net/amr.396-398.2018.

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Continuous processing in the microreactor represents a novel way for the safe and expedient conduct of high energetic nitration. Apart from handling benefits,nitration in microreactors proceed under precisely controlled conditions providing improved yields and selectivity. This paper studied the nitration of toluene in the microglass reactor using concentrated nitric acid as the nitrating agent and SO3H-functional ionic liquids, Lanthanide(iii) trifluoroacetate as recyclable catalysts. We described a mild, efficient process for the nitration of toluene.

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Elfering, S. L., V. L. Haynes, N. J. Traaseth, A. Ettl, and Cecilia Giulivi. "Aspects, mechanism, and biological relevance of mitochondrial protein nitration sustained by mitochondrial nitric oxide synthase." American Journal of Physiology-Heart and Circulatory Physiology 286, no. 1 (January 2004): H22—H29. http://dx.doi.org/10.1152/ajpheart.00766.2003.

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The goal of this study was to explore the occurrence of nitrated proteins in mitochondria given that these organelles are endowed with a mitochondrial nitric oxide (NO·) synthase and considering the important role that mitochondria have in energy metabolism. Our hypothesis is that nitration of proteins constitutes a posttranslational modification by which NO· exhibits long-term effects above and beyond those bioregulatory ones mediated through the interaction with cytochrome c oxidase. Our studies are aimed at understanding the mechanisms underlying the nitration of proteins in mitochondria and the biological significance of such a process in the cellular milieu. On promoting a sustained NO· production by mitochondria, we investigated various aspects of protein nitration. Among them, the localization of nitrated proteins in mitochondrial subfractions, the identification of nitrated proteins through proteomic approaches, the characterization of affected pathways, and depiction of a target sequence. The biological relevance was analyzed by considering the turnover of native and nitrated proteins. In this regard, mitochondrial dysfunction, ensuing nitrative stress, may be envisioned as the result of accumulation of nitrated proteins, resulting from an overproduction of endogenous NO· (this study), a failure in the proteolytic system to catabolize modified proteins, or a combination of both. Finally, this study allows one to gain understanding on the mechanism and nitrating species underlying mitochondrial protein nitration.

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Petre, Brínduşa-Alina, Nikolay Youhnovski, Juho Lukkari, Reinhold Weber, and Michael Przybylski. "Structural Characterisation of Tyrosine-Nitrated Peptides by Ultraviolet and Infrared Matrix-Assisted Laser Desorption/Ionisation Fourier Transform Ion Cyclotron Resonance Mass Spectrometry." European Journal of Mass Spectrometry 11, no. 5 (October 2005): 513–18. http://dx.doi.org/10.1255/ejms.777.

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Nitration of tyrosine residues in proteins may occur in cells upon oxidative stress and inflammation processes mediated through generation of reactive nitroxyl from peroxynitrite. Tyrosine nitration from oxidative pathways may generate cytotoxic species that cause protein dysfunction and pathogenesis. A number of protein nitrations in vivo have been reported and some specific Tyrosine nitration sites have been recently identified using mass spectrometric methods. High-resolution Fourier transform ion cyclotron resonance mass spectrometry (MALDI) FT-ICR-MS) is shown here to be a highly efficient method in the determination of protein nitrations. Following the identification of nitration of the catalytic site Tyr–430 residue of bovine prostacyclin synthase, we synthesised several model peptides containing both unmodified tyrosine and 3-nitro-tyrosine residues, using solid-phase peptide synthesis (SPPS). The structures of the nitrotyrosine peptides were characterised both by ESI- and by matrix-assisted laser desorption/ionisation (MALDI)-FT-ICR-MS, using a standard ultraviolet (UV) nitrogen nitrogen laser and a 2.97 μm Nd-YAG infrared laser. Using UV-MALDI-MS, 3-nitrotyrosyl-peptides were found to undergo extensive photochemical fragmentation at the nitrophenyl group, which may hamper or prevent the unequivocal identification of Tyr-nitrations in cellular proteins. In contrast, infrared-MALDI-FT-ICR-MS did not produce fragmentation of molecular ions of Tyr-nitrated peptides.

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Haynes, Virginia, Nathaniel J. Traaseth, Sarah Elfering, Yasuko Fujisawa, and Cecilia Giulivi. "Nitration of specific tyrosines in FoF1 ATP synthase and activity loss in aging." American Journal of Physiology-Endocrinology and Metabolism 298, no. 5 (May 2010): E978—E987. http://dx.doi.org/10.1152/ajpendo.00739.2009.

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It has been reported that C-nitration of proteins occurs under nitrative/oxidative stress; however, its role in pathophysiological situations is not fully understood. In this study, we determined that nitration of Tyr345 and Tyr368 in the β-subunit of the mitochondrial FoF1-ATPase is a major target for nitrative stress in rat liver under in vivo conditions. The chemical characteristics of these Tyr make them suitable for a facilitated nitration (solvent accessibility, consensus sequence, and p Ka). Moreover, β-subunit nitration increased significantly with the age of the rats (from 4 to 80 weeks old) and correlated with decreased ATP hydrolysis and synthesis rates. Although its affinity for ATP binding was unchanged, maximal ATPase activity decreased between young and old rats by a factor of two. These changes directly impacted the available ATP concentration in vivo, and it was expected that they would affect multiple cellular ATP-dependent processes. For instance, at least 50% of available [ATP] in the liver of older rats would have to be committed to sustain maximal Na+-K+-ATPase activity, whereas only 30% would be required for young rats. If this requirement was not fulfilled, the osmoregulation and Na+-nutrient cotransport in liver of older rats would be compromised. On the basis of our studies, we propose that targeted nitration of the β-subunit is an early marker for nitrative stress and aging.

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Buan, Ivy Joyce Arenas, and Dyanne Jane Cid Duldulao. "Microwave-Assisted Synthesis of Para-Nitrophenol Using Calcium Nitrate." Oriental Journal Of Chemistry 37, no. 1 (February 28, 2021): 243–46. http://dx.doi.org/10.13005/ojc/370134.

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Conventional process of nitrating phenolic compounds involves the use of excess corrosive reagents that impose environmental threats. Rapid and environmentally friendly microwave-assisted nitration of phenol has been employed to limit the use of corrosive nitric acid and sulfuric acid. In this study, phenol is reacted to calcium nitrate and acetic acid, which served as nitrating agents. The solution is irradiated under microwave to complete the nitration process. This microwave-assisted- synthesis is a rate- enhanced process that showed complete nitration in a short reaction time of 1 min with a high yield of 89%. Bands of phenyl ring, OH, CO, and nitro groups observed in the FTIR spectra correspond to the vibration modes of para-nitrophenol. GCMS analysis showed a retention time of 7 min for the product with 139m/z base peak with matches that confirms the synthesis of para- nitrophenol. This microwave-assisted method can be employed as an efficient, environmentally safe, and rapid alternative nitration method for the synthesis of para-nitrophenol.

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9

Zhan, Xianquan, Yuda Huang, and Shehua Qian. "Protein Tyrosine Nitration in Lung Cancer: Current Research Status and Future Perspectives." Current Medicinal Chemistry 25, no. 29 (September 26, 2018): 3435–54. http://dx.doi.org/10.2174/0929867325666180221140745.

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Oxidative/nitrative damage is a crucial element among the complex factors that contribute to lung carcinogenesis. Nitric oxide (NO) free radicals, through chemical modifications such as tyrosine nitration, are significantly involved in lung carcinogenesis and metastasis. NO-mediated protein nitration, which is the addition of the nitro group (–NO2) to position 3 of the phenolic ring of a tyrosine residue, is an important molecular event in lung cancer, and has been studied with mass spectrometry. Nitration is involved in multiple biological processes, including signal transduction, protein degradation, energy metabolism, mitochondrial dysfunction, enzyme inactivation, immunogenic response, apoptosis, and cell death. This article reviews the relationship of NO and its derivates and lung cancer, formation and roles of tyrosine nitration in lung cancer, differences of protein nitration between lung cancer and other inflammatory pulmonary diseases, current status of protein nitration and nitroproteomics in lung cancer, and future perspectives to achieve a better understanding of lung carcinogenesis, for biomarker discovery; and for new diagnostic and prognostic monitoring, and therapeutic targets.

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Aulak, Kulwant S., Thomas Koeck, John W. Crabb, and Dennis J. Stuehr. "Dynamics of protein nitration in cells and mitochondria." American Journal of Physiology-Heart and Circulatory Physiology 286, no. 1 (January 2004): H30—H38. http://dx.doi.org/10.1152/ajpheart.00743.2003.

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Nitric oxide is a precursor of reactive nitrating species such as peroxynitrite and nitrogen dioxide that modify proteins to generate 3-nitrotyrosine. Many diseases are associated with increased levels of protein-bound nitrotyrosine, and this is used as a marker for oxidative damage. However, the regulation of protein nitration and its role in cell function are unclear. We demonstrate that biological protein nitration can be a specific and dynamic process. Proteins were nitrated in distinct temporal patterns in cells undergoing inflammatory activation, and protein denitration and renitration occurred rapidly in respiring mitochondria. The targets of protein nitration varied over time, which may reflect their sensitivity to nitration, expression pattern, or turnover. The dynamic nature of the nitration process was revealed by denitration and renitration of proteins occurring within minutes in mitochondria that were subject to hypoxiaanoxia and reoxygenation. Our results have implications that are particularly important for ischemia-reperfusion injury.

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Gole, Madhura D., Jose M. Souza, Irene Choi, Caryn Hertkorn, Stuart Malcolm, Raymond F. Foust, Barbara Finkel, Paul N. Lanken, and Harry Ischiropoulos. "Plasma proteins modified by tyrosine nitration in acute respiratory distress syndrome." American Journal of Physiology-Lung Cellular and Molecular Physiology 278, no. 5 (May 1, 2000): L961—L967. http://dx.doi.org/10.1152/ajplung.2000.278.5.l961.

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The present study identifies proteins modified by nitration in the plasma of patients with ongoing acute respiratory distress syndrome (ARDS). The proteins modified by nitration in ARDS were revealed by microsequencing and specific antibody detection to be ceruloplasmin, transferrin, α1-protease inhibitor, α1-antichymotrypsin, and β-chain fibrinogen. Exposure to nitrating agents did not deter the chymotrypsin-inhibiting activity of α1-antichymotrypsin. However, the ferroxidase activity of ceruloplasmin and the elastase-inhibiting activity of α1-protease inhibitor were reduced to 50.3 ± 1.6 and 60.3 ± 5.3% of control after exposure to the nitrating agent. In contrast, the rate of interaction of fibrinogen with thrombin was increased to 193.4 ± 8.5% of the control value after exposure of fibrinogen to nitration. Ferroxidase activity of ceruloplasmin and elastase-inhibiting activity of the α1-protease inhibitor in the ARDS patients were significantly reduced (by 81 and 44%, respectively), whereas α1-antichymotrypsin activity was not significantly altered. Posttranslational modifications of plasma proteins mediated by nitrating agents may offer a biochemical explanation for the reported diminished ferroxidase activity, elevated levels of elastase, and fibrin deposits detected in patients with ongoing ARDS.

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Lakhmanov, D. E., Yu G. Khabarov, V. A. Veshnyakov, and M. R. Yokubjanov. "Nitration of Hydrolysis Lignin in Water-Aprotic Solvent Mixtures." Lesnoy Zhurnal (Forestry Journal), no. 5 (November 5, 2020): 184–92. http://dx.doi.org/10.37482/0536-1036-2020-5-184-192.

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Industrial lignins are formed from native lignins during chemical or biochemical processing of plant raw materials. Lignins can be modified to produce valuable products, including monomers, polymeric materials, and composites. The article presents the results of a study of hydrolysis lignin nitration under various conditions. The aim of the study was to obtain a nitrated hydrolysis lignin with a maximum yield and maximum nitrogen content. Therefore, the nitration was carried out using nitric acid in a water-aprotic solvent binary mixtures (1,4-dioxane, dimethyl sulfoxide, tetrahydrofuran, dimethylformamide, acetonitrile). Acetyl nitrate, which is a mixed anhydride of nitric and acetic acids, was also used as a nitrating agent. In this regard, the consumption of acetic anhydride in the synthesis of acetyl nitrate was used taking into account the water present in concentrated nitric acid. Acetyl nitrate was obtained by the reaction of acetic anhydride and concentrated nitric acid at room temperature for 30 min. Acetyl nitrate is a mild nitrating agent opposed to nitric acid. Nitration was carried out under reflux in a boiling water bath for 2–5 min (with nitric acid) or 1–60 min (with acetyl nitrate). Upon completion of the nitration reaction, the products were filtered, washed with distilled water and dried to constant weight without heating. When nitration was performed with nitric acid, the maximum yield of nitrated hydrolysis lignin (83–101 %) was achieved using 1,4-dioxane, acetonitrile, and tetrahydrofuran; and the maximum nitrogen content (4.3–4.5 %) was achieved using 1,4-dioxane or acetonitrile. The use of dimethyl sulfoxide and dimethylformamide leads to a decrease in the product yield to 23–35 %, to a lower nitrogen content of 1.3–3.9 % and an increased oxygen content, which indicates the occurrence of not only nitration, but also depolymerization and oxidative transformations. When nitration with acetyl nitrate, the reaction takes place for 1–3 min, herewith the product contains up to 4.7 % of nitrogen. On the IR spectra of nitrated hydrolysis lignins, new absorption bands appear at 1555 and 1710 cm–1 due to the appearance of carboxyl and nitro groups.

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Dong, Xiongzi, and Xinhua Peng. "Regioselective Nitration of m-Xylene Catalyzed by Zeolite Catalyst." Australian Journal of Chemistry 68, no. 7 (2015): 1122. http://dx.doi.org/10.1071/ch14551.

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Nitration with nitric acid and acetic anhydride via acetyl nitrate as nitrating species is efficient with the substrate m-xylene as solvent. Zeolite Hβ with an SiO2/Al2O3 ratio of 500 was found to be the most active of the catalysts tried both in yield and regioselectivity in the nitration of m-xylene. The molecular volume of the reactants was calculated with the Gaussian 09 program at the B3LYP/6–311+G(2d, p) level and compared with the size of the zeolite Hβ channels. A range of other substrates were subjected to the nitrating system under the same conditions as those optimized for m-xylene and excellent selectivity was obtained.

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Yamato, Takehiko, Koji Tsuchihashi, Noriko Nakamura, Mai Hirahara, and Hirohisa Tsuzuki. "Medium-sized cyclophanes, part 59:1 Nitration of [3.3]- and [3.3.3]metacyclophanes Through-space electronic interactions between two or three benzene rings." Canadian Journal of Chemistry 80, no. 2 (February 1, 2002): 207–15. http://dx.doi.org/10.1139/v02-009.

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The two tert-butyl groups of anti-6,15-di-tert-butyl-9,18-dimethoxy[3.3]metacyclophane (anti-4) are both ipso-nitrated even under mild reaction conditions such as copper(II) nitrate in an acetic anhydride solution because of the decreased deactivation of the second aromatic ring by the introduced nitro group. On the other hand, anti-5,13-di-tert-butyl-8,16-dimethoxy[2.2]metacyclophane (anti-1) undergoes replacement of only one tert-butyl group under the same reaction conditions. The higher yields of the twofold ipso-nitration product anti-7 were obtained in nitration of anti-4 with fuming nitric acid or mixed acid (HNO3H2SO4). Thus, the number of ipso-nitrations at the tert-butyl groups of anti-4 was strongly affected by the reactivity of the nitration reagent. Nitration of the corresponding syn-conformer syn-4 with copper(II) nitrate in an acetic anhydride solution, however, led only to the recovery of the starting compound. The presently developed procedure was further applied to the direct removal of the tert-butyl group by electrophilic substitution of the larger-sized ring macrocyclic metacyclophanes, cone- and partial-cone-tri-tert-butyl[3.3.3]metacyclophanes 11.Key words: [3n]metacyclophanes, conformation, ipso-nitration, through-space electronic interaction, crystal structure.

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Moosavi-Zare, Ahmad Reza, Mohammad Ali Zolfigol, Mahmoud Zarei, Ehsan Noroozizadeh, and M. Hassan Beyzavi. "Nitration of arenes by 1-sulfopyridinium nitrate as an ionic liquid and reagent by in situ generation of NO2." RSC Advances 6, no. 92 (2016): 89572–77. http://dx.doi.org/10.1039/c6ra15922b.

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Yi, Xiaofei, Kai Chen, Wei Chen, Wanzhi Chen, Miaochang Liu, and Huayue Wu. "Synthesis of cyclic gem-dinitro compounds via radical nitration of 1,6-diynes with Fe(NO3)3·9H2O." Organic & Biomolecular Chemistry 17, no. 19 (2019): 4725–28. http://dx.doi.org/10.1039/c9ob00431a.

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ANDREKOPOULOS, Christopher, Hao ZHANG, Joy JOSEPH, Shasi KALIVENDI, and B. KALYANARAMAN. "Bicarbonate enhances alpha-synuclein oligomerization and nitration: intermediacy of carbonate radical anion and nitrogen dioxide radical." Biochemical Journal 378, no. 2 (March 1, 2004): 435–47. http://dx.doi.org/10.1042/bj20031466.

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α-Synuclein, a neuronal presynaptic protein, has been reported to undergo oligomerization to form toxic Lewy bodies in neurodegenerative disorders. One of the proposed mechanisms for aggregation of α-synuclein involves oxidative and nitrative modifications. In the present study, we show that addition of 3-morpholino-sydnonimine chloride (SIN-1) or slow infusion of pre-formed peroxynitrite (ONOO−) to mixtures containing α-synuclein and HCO3− markedly enhanced both nitration and aggregation of α-synuclein through dityrosine formation. Bicarbonate-dependent peroxidase activity of Cu,Zn-superoxide dismutase (SOD1) also induced covalent aggregation of α-synuclein via a CO3•−-dependent mechanism. Nitrone spin traps completely inhibited CO3•−-mediated oxidation/nitration and aggregation of α-synuclein. Conversely, α-synuclein inhibited CO3•−-induced spin adduct formation. Independent evidence for CO3•−-mediated oxidation and dimerization of α-synuclein was obtained from UV photolysis of [(NH3)5CoCO3]+, which generates authentic CO3•−. Irradiation of [(NH3)5CoCO3]+ and NO2− in the presence of α-synuclein yielded nitration and aggregation products that were similar to those obtained from a SIN-1 (or slowly infused ONOO−) and HCO3− or a myeloperoxidase/H2O2/NO2− system. Hydrophobic membranes greatly influenced α-synuclein aggregation and nitration in these systems. We conclude that both CO3•− and NO2• could play a major role in the nitration/aggregation of α-synuclein.

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Stojanovic, Srdjan, Dragana Stanic, Milan Nikolic, Smiljana Raicevic, Mihajlo Spasic, and Vesna Niketic. "Manganese superoxide dismutase (MnSOD) catalyzes NO-dependent tyrosine residue nitration." Journal of the Serbian Chemical Society 70, no. 4 (2005): 601–8. http://dx.doi.org/10.2298/jsc0504601s.

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The peroxynitrite-induced nitration of manganese superoxide dismutase (MnSOD) tyrosine residue, which causes enzyme inactivation, is well established. This led to suggestions that MnSOD nitration and inactivation in vivo, detected in various diseases associated with oxidative stress and overproduction of nitric monoxide (NO), conditions which favor peroxynitrite formation, is also caused by peroxynitrite. However, our previous in vitro study demonstrated that exposure of MnSOD to NO led to NO conversion into nitrosonium (NO+) and nitroxyl (NO?) species, which caused enzyme modifications and inactivation. Here it is reported that MnSOD is tyrosine nitrated upon exposure to NO, as well as that MnSOD nitration contributes to inactivation of the enzyme. Collectively, these observations provide a compelling argument supporting the generation of nitrating species in MnSOD exposed to NO and shed a new light on MnSOD tyrosine nitration and inactivation in vivo. This may represent a novel mechanism by which MnSOD protects cell from deleterious effects associated with overproduction of NO. However, extensive MnSOD modification and inactivation associated with prolonged exposure to NO will amplify the toxic effects caused by increased cell superoxide and NO levels.

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Pérez de la Lastra, José Manuel, Celia Andrés Juan, Francisco J. Plou, and Eduardo Pérez-Lebeña. "The Nitration of Proteins, Lipids and DNA by Peroxynitrite Derivatives-Chemistry Involved and Biological Relevance." Stresses 2, no. 1 (January 29, 2022): 53–64. http://dx.doi.org/10.3390/stresses2010005.

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In recent years, much interest has been generated by the idea that nitrosative stress plays a role in the aetiology of human diseases, such as atherosclerosis, inflammation, cancer, and neurological diseases. The chemical changes mediated by reactive nitrogen species (RNS) are detrimental to cell function, because they can cause nitration, which can alter the structures of cellular proteins, DNA, and lipids, and hence, impair their normal function. One of the most potent biological nitrosative agents is peroxynitrite (ONOO−), which is produced when nitric oxide (•NO) and superoxide (•O2−) are combined at extremely rapid rates. Considering the plethora of oxidations by peroxynitrite, this makes peroxynitrite the most prevalent nitrating species responsible for protein, DNA, and lipids nitration in vivo. There is biochemical evidence to suggest that the interactions of the radicals NO and superoxide result in the formation of a redox system, which includes the reactions of nitrosation and nitration, and is a component of the complex cellular signalling network. However, the chemistry involved in the nitration process with peroxynitrite derivatives is poorly understood, particularly for biological molecules, such as DNA, proteins, and lipids. Here, we review the processes involved in the nitration of biomolecules, and provide a mechanistic explanation for the chemical reactions of NOS and nitrosative stress. This study reveals that these processes are based on a surprisingly simple and straightforward chemistry, with a fascinating influence on cellular physiology and pathology.

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Stefanelli, Manuela, Sara Nardis, Frank R. Fronczek, Kevin M. Smith, and Roberto Paolesse. "Copper β-trinitrocorrolates." Journal of Porphyrins and Phthalocyanines 17, no. 06n07 (June 2013): 440–46. http://dx.doi.org/10.1142/s1088424613500120.

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The β-nitration reaction carried out on the corrole macrocycle has been shown to be extremely regioselective, although the reduced symmetry of the macrocycle could potentially lead to a huge number of possible regioisomers. We recently reported that the careful use of AgNO 2/ NaNO 2 as a nitrating system enabled the achievement in good yields of mono- and dinitro-derivatives on both corrole free base and its copper complex, proving to be an efficient and cost-effective method. In this work, we present a detailed study of the scope of this method using TtBuCorrH 3 as a model corrole. A further increase of the oxidant pushes the nitration up to the functionalization of three β-pyrrolic positions, although concomitant decomposition of the macrocycle is also observed. The application of the proven nitration method with a five-fold excess of both silver and sodium nitrites with respect to corrole, afforded the 2,3,17-( NO 2)3- TtBuPCorrCu as the main product, in 25% yield, together with traces of another compound identified by X-ray crystallographic analysis as the 3,8,17-( NO 2)3- TtBuPCorrCu isomer. In light of these recent results, we also reinvestigated the characterization of the nitration products obtained from bis-substitution reactions, allowing among others the identification of the copper 3,8-( NO 2)2 corrolate.

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Honoré, Jean-Claude, Amna Kooli, Xin Hou, David Hamel, José Carlos Rivera, Émilie Picard, Pierre Hardy, et al. "Sustained hypercapnia induces cerebral microvascular degeneration in the immature brain through induction of nitrative stress." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 298, no. 6 (June 2010): R1522—R1530. http://dx.doi.org/10.1152/ajpregu.00807.2009.

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Hypercapnia is regularly observed in chronic lung disease, such as bronchopulmonary dysplasia in preterm infants. Hypercapnia results in increased nitric oxide synthase activity and in vitro formation of nitrates. Neural vasculature of the immature subject is particularly sensitive to nitrative stress. We investigated whether exposure to clinically relevant sustained high CO2 causes microvascular degeneration in the newborn brain by inducing nitrative stress, and whether this microvascular degeneration has an impact on brain growth. Newborn rat pups were exposed to 10% CO2 as inspired gas (PaCO2 = 60–70 mmHg) starting within 24 h of birth until postnatal day 7 (P7). Brains were notably collected at different time points to measure vascular density, determine brain cortical nitrite/nitrate, and trans-arachidonic acids (TAAs; products of nitration) levels as effectors of vessel damage. Chronic exposure of rat pups to high CO2 (PaCO2 ≈ 65 mmHg) induced a 20% loss in cerebrovascular density at P3 and a 15% decrease in brain mass at P7; at P30, brain mass remained lower in CO2-exposed animals. Within 24 h of exposure to CO2, brain eNOS expression and production of nitrite/nitrate doubled, lipid nitration products (TAAs) increased, and protein nitration (3-nitrotyrosine immunoreactivity) was also coincidently augmented on brain microvessels (lectin positive). Intracerebroventricular injection of TAAs (10 μM) replicated cerebrovascular degeneration. Treatment of rat pups with NOS inhibitor (l-Nω-nitroarginine methyl ester) or a peroxynitrite decomposition catalyst (FeTPPS) prevented hypercapnia-induced microvascular degeneration and preserved brain mass. Cytotoxic effects of high CO2 were reproduced in vitro /ex vivo on cultured endothelial cells and sprouting microvessels. In summary, hypercapnia at values frequently observed in preterm infants with chronic lung disease results in increased nitrative stress, which leads to cerebral cortical microvascular degeneration and curtails brain growth.

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Sudarma, I. M., A. Shofiati, and M. G. Darmayanti. "Nitration of Methyl Eugenol Derived from Clove Oil." Asian Journal of Chemistry 32, no. 1 (November 18, 2019): 17–20. http://dx.doi.org/10.14233/ajchem.2020.22114.

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No report is available in literature for the nitration of methyl eugenol. The main goal of this work is to find an efficient method for the synthesis of 5-nitro-methyl eugenol. 5-Nitro-methyl eugenol is of considerable importance in the production of other fine chemicals such as 5-amino-methyl eugenol for further chemical synthesis and has also possible to enhance its biological properties and other applications. The methyl eugenol can be prepared from methylation of eugenol which can be isolated from clove oil. In an attempt to synthesize nitro-methyl eugenol in high yield, three different nitration methods of methyl eugenol have been applied. Method (a) gave 5.97 %, (b) 84.37 % and (c) 11.40 %. Method (b) using a nitrating consisting mixture of HNO3 and H2SO4 under mild condition has been found to give 5-nitro-methyl eugenol in good yield.

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Besser, Charlotte, Adam Agocs, Andjelka Ristic, and Marcella Frauscher. "Implementation of Nitration Processes in Artificial Ageing for Closer-to-Reality Simulation of Engine Oil Degradation." Lubricants 10, no. 11 (November 5, 2022): 298. http://dx.doi.org/10.3390/lubricants10110298.

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During their service, engine oils suffer from various influencing parameters such as thermo-oxidative stress and nitration, hence, the accumulation of degradation products and the entry of contaminants. Accordingly, ICEs need to be able to operate satisfactorily, especially with a degraded lubricant, making it highly recommendable to use such oils for component testing in ICE development. Thus, a new nitrative thermo-oxidative ageing method is presented for closer-to-reality simulation of engine oil alteration with the intention to provide reproducibly aged oils for subsequent bench testing. With this method, a target used oil from field application was replicated and the comparability of oil condition in the lab vs. field regarding oxidation, nitration, additive depletion, and acidification amongst others was verified by conventional and advanced analyses. Special focus was laid on the identification of nitration products, proving them to be predominantly oxidized aromatic species or organophosphates. The presented method gives valuable benefit for the closer-to-reality ageing of engine oils in reasonable time frames with moderate costs and, hence, for the provision of test oils for ICE bench testing enabling rapid engine component assessment.

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Buchczyk, Darius P., Karlis Briviba, F. Ulrich Hartl, and Helmut Sies. "Responses to Peroxynitrite in Yeast: Glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) as a Sensitive Intracellular Target for Nitration and Enhancement of Chaperone Expression and Ubiquitination." Biological Chemistry 381, no. 2 (February 15, 2000): 121–26. http://dx.doi.org/10.1515/bc.2000.017.

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Abstract Peroxynitrite (ONOO−), a potent oxidizing and nitrating species, has been linked to covalent modifications of biomolecules in a number of pathological conditions. In S. cerevisiae, a model eukaryotic cell system, ONOO− was found to be more potent than hydrogen peroxide in oxidizing thiols, inducing heat shock proteins (Hsp70) and enhancing the ubiquitination of proteins. As identified by microsequence analysis following immunoprecipitation with anti-nitrotyrosine antibodies, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was especially susceptible to nitration by ONOO− in yeast cells. The activity of this enzyme was strongly inhibited upon steady-state exposure of the cells to low doses of ONOO− in yeast and in cultured rat astrocytes. Thus, ONOO− is a potent stressor in yeast capable of inducing oxidative damage and protein nitration, with GAPDH being a preferential target protein that is efficiently inactivated.

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25

Zhang, Hui, Qi Sun, Teng Liu, Lu Ma, Panpan Zhen, Ke Wang, Lingqiao Lu, et al. "Alleviation of Plasma Homocysteine Level by Phytoestrogenα-Zearalanol Might Be Related to the Reduction of Cystathionineβ-Synthase Nitration." BioMed Research International 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/143192.

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Hyperhomocysteinemia is strongly associated with cardiovascular diseases. Previous studies have shown that phytoestrogenα-zearalanol can protect cardiovascular system from hyperhomocysteinemia and ameliorate the level of plasma total homocysteine; however, the underlying mechanisms remain to be clarified. The aim of this research is to investigate the possible molecular mechanisms involved in ameliorating the level of plasma homocysteine byα-zearalanol. By the successfully established diet-induced hyperhomocysteinemia rat models, we found that, afterα-zearalanol treatment, the activity of cystathionineβ-synthase, the key enzyme in homocysteine metabolism, was significantly elevated and level of nitrative stress in liver was significantly reduced. In correlation with this, results also showed a decreased nitration level of cystathionineβ-synthase in liver. Together data implied that alleviation of plasma homocysteine level by phytoestrogenα-zearalanol might be related to the reduction of cystathionineβ-synthase nitration.

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Sasmal, Sheuli, Soumya Kumar Sinha, Goutam Kumar Lahiri, and Debabrata Maiti. "A directing group-assisted ruthenium-catalyzed approach to access meta-nitrated phenols." Chemical Communications 56, no. 52 (2020): 7100–7103. http://dx.doi.org/10.1039/d0cc02851g.

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meta-Selective C–H nitration of phenol derivatives was developed using a Ru-catalyzed σ-activation strategy. Cu(NO₃)₂·3H₂O was employed as the nitrating source, whereas Ru₃(CO)₁₂ was found to be the most suitable metal catalyst for the protocol.

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27

Khan, Md Asad, Md Faiz Akram, Khursheed Alam, Haseeb Ahsan, and Moshahid A. Rizvi. "Peroxynitrite-Mediated Structural Changes in Histone H2A: Biochemical and Biophysical Analysis." Protein & Peptide Letters 27, no. 10 (November 2, 2020): 989–98. http://dx.doi.org/10.2174/0929866527666200427213722.

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Background: Peroxynitrite, a nitrating and oxidizing agent, is formed by the interaction between nitric oxide and superoxide radicals. H2A histone is a basic nucleoprotein and is one of the major core histones responsible for packaging DNA. It has been shown that they are highly sensitive to oxidizing and nitrating agents. Objective: Nitration of tyrosine residues in proteins by peroxynitrite is regarded as a marker of nitrosative damage. The dityrosine bond, an oxidative covalent cross-link between two tyrosines in protein, is increasingly identified as a marker of oxidative stress, aging and neurodegerative diseases. Methods: Peroxinitrite-mediated nitration and dinitration in H2A histone was assessed by various biophysical techniques. Results: The data presented in this study showed that the dityrosine content was found to be elevated in H2A histone modified with peroxynitrite. The formation of dityrosine showed a decrease in fluorescence intensity, generation of a new peak in FT-IR, increase in hydrodynamic size, and loss of secondary and tertiary structure of H2A resulting in a partially folded structure. Conclusion: We report that H2A may undergo conformational and structural changes under nitrosative and oxidative stress from the deleterious effects of peroxynitrite.

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Brito, Cecilia, Mercedes Naviliat, Adriana C. Tiscornia, Francoise Vuillier, Gabriela Gualco, Guillaume Dighiero, Rafael Radi, and Alfonso M. Cayota. "Peroxynitrite Inhibits T Lymphocyte Activation and Proliferation by Promoting Impairment of Tyrosine Phosphorylation and Peroxynitrite-Driven Apoptotic Death." Journal of Immunology 162, no. 6 (March 15, 1999): 3356–66. http://dx.doi.org/10.4049/jimmunol.162.6.3356.

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Abstract Peroxynitrite (ONOO−) is a potent oxidizing and nitrating agent produced by the reaction of nitric oxide with superoxide. It readily nitrates phenolic compounds such as tyrosine residues in proteins, and it has been demonstrated that nitration of tyrosine residues in proteins inhibits their phosphorylation. During immune responses, tyrosine phosphorylation of key substrates by protein tyrosine kinases is the earliest of the intracellular signaling pathways following activation through the TCR complex. This work was aimed to evaluate the effects of ONOO− on lymphocyte tyrosine phosphorylation, proliferation, and survival. Additionally, we studied the generation of nitrating species in vivo and in vitro during immune activation. Our results demonstrate that ONOO−, through nitration of tyrosine residues, is able to inhibit activation-induced protein tyrosine phosphorylation in purified lymphocytes and prime them to undergo apoptotic cell death after PHA- or CD3-mediated activation but not upon phorbol ester-mediated stimulation. We also provide evidence indicating that peroxynitrite is produced during in vitro immune activation, mainly by cells of the monocyte/macrophage lineage. Furthermore, immunohistochemical studies demonstrate the in vivo generation of nitrating species in human lymph nodes undergoing mild to strong immune activation. Our results point to a physiological role for ONOO− as a down-modulator of immune responses and also as key mediator in cellular and tissue injury associated with chronic activation of the immune system.

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LIU, MIN-HSIEN, KEN-FA CHENG, CHENG CHEN, and YAW-SUN HONG. "SOLVENT EFFECT ON ELECTROPHILIC AND RADICAL SUBSTITUTION OF TOLUENE MONONITRATION REACTIONS." Journal of Theoretical and Computational Chemistry 07, no. 05 (October 2008): 965–76. http://dx.doi.org/10.1142/s0219633608004222.

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Two kinds of nitrating reagents, a nitronium cation [Formula: see text] and a nitro radical (· NO 2), were used in the gaseous phase toluene mononitration reaction. The closed shell calculation for electrophilic substitution and open shell calculation for radical substitution were both performed in solventless, H 2 O -solvated, and CH 3 OH -solvated molecular reaction systems. In the series of electrophilic toluene nitration reactions, both ortho-nitro toluene (o-MNT) and para-nitro toluene (p-MNT) are more abundant products than meta-nitro toluene (m-MNT), no matter what solvent is used in the reaction system. The reaction energy barrier for obtaining each kind of mononitro toluene follows a stepwise decreasing trend when the reaction is carried out in the solventless, H 2 O -solvated, and CH 3 OH -solvated systems. In all radical toluene nitration reactions, solventless or solvated, m-MNT is the most abundant product. The energy barrier data also show that the nitration reaction is more feasible in a solvated than in a solventless system. H 2 O has a more obvious solvent effect than CH 3 OH in the · NO 2 radical substitution reaction, and the H 2 O -solvated system provides a lower activation energy reaction path.

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30

Martynov, I. V., V. I. Uvarov, V. K. Brel', V. I. Anufriev, and A. V. Yarkov. "Nitration of fluoroethylenes by nitrating mixture (HNO3+H2O4+SO3)." Bulletin of the Academy of Sciences of the USSR Division of Chemical Science 38, no. 12 (December 1989): 2500–2503. http://dx.doi.org/10.1007/bf00962433.

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GALIÑANES, Manuel, and Bashir M. MATATA. "Protein nitration is predominantly mediated by a peroxynitrite-dependent pathway in cultured human leucocytes." Biochemical Journal 367, no. 2 (October 15, 2002): 467–73. http://dx.doi.org/10.1042/bj20020825.

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Protein nitration is a common characteristic of oxidative injury caused by the invasion of leucocytes into inflammatory lesions. Two distinct pathways of nitration of protein tyrosine residues, namely the peroxynitrite (ONOO-)-mediated pathway and another catalysed by the haem-containing peroxidases, have been reported under experimental conditions. However, the contribution of these two pathways in human leucocytes is still controversial. The present study demonstrates that the process of phenolic nitration of proteins in cultured human leucocytes is mainly ONOO--mediated and that it differs between granulocytes and mononuclear cells, depending on the cell compartment and the stimuli. We have also shown that NO induces protein nitration via a ONOO--dependent pathway, whereas NO2-, the NO metabolite, does not increase but decreases nitration in PMA-stimulated leucocytes. The inhibition of myeloperoxidase activity did not reduce protein nitration; on the other hand, the myeloperoxidase inhibitor aminobenzoic hydrazide caused increased nitration, which was mediated by ONOO-. These results suggest that protein nitration is predominantly mediated by a ONOO--dependent pathway in cultured human leucocytes and that the myeloperoxidase-catalysed pathway does not play a significant role in protein nitration.

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32

Trostchansky, Andrés, Summer Lind, Roberto Hodara, Tomoyuki Oe, Ian A. Blair, Harry Ischiropoulos, Homero Rubbo, and José M. Souza. "Interaction with phospholipids modulates α-synuclein nitration and lipid–protein adduct formation." Biochemical Journal 393, no. 1 (December 12, 2005): 343–49. http://dx.doi.org/10.1042/bj20051277.

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Intracellular aggregates of α-syn (α-synuclein) represent pathoanatomical hallmarks of neurodegenerative disorders (synucleinopathies). The molecular mechanisms underlying α-syn aggregation into filamentous inclusions may involve oxidation and nitration of the protein. Whereas the effects of oxidants and nitrating species on soluble α-syn have been studied in detail, the effect of these reactive species on α-syn associated with lipids is still unknown. In the present paper, we report that α-syn bound to small unilamellar liposomes composed of phosphatidylcholine/phosphatidic acid is resistant to oxidation and nitration when compared with soluble α-syn. Additionally, increasing concentrations of unsaturated fatty acids diminished the oxidation and nitration of α-syn upon exposure to fluxes of peroxynitrite (8–20 μM·min−1). To investigate the effect of oxidized lipids on α-syn, the protein was incubated with the bifunctional electrophile 4-HNE [4-hydroxy-2(E)-nonenal]. MS analysis showed the formation of three major products corresponding to the native protein and α-syn plus one or two 4-HNE molecules. Trypsin digestion of the modified protein followed by peptide ‘finger-printing’ revealed that 4-HNE modified the peptide E46GVVHGVATVAEK58. Further analysis of the peptides with liquid chromatography–tandem MS identified the modified residue as His50. The data indicate that the association of α-syn with biological membranes protects the protein from oxidation and nitration and thus diminishes the formation of protein molecules capable of forming aggregates. However, products of lipid peroxidation can also modify α-syn, generating novel protein adducts that could serve as biomarkers for documenting oxidative processes in human as well as animal and cellular models of α-syn aggregation and pathology.

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Song, Si-Zhe, Youren Dong, Guo-Ping Ge, Qiang Li, and Wen-Ting Wei. "Recent Advances in Radical Nitration Using tert-Butyl Nitrite." Synthesis 52, no. 06 (January 8, 2020): 796–806. http://dx.doi.org/10.1055/s-0039-1690789.

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Nitro compounds serve as valuable intermediates for pharmaceuticals, agrochemicals, dyes, and polymers. In recent years, radical nitration using tert-butyl nitrite (t-BuONO) has attracted wide attention and desirable progress has been made. On the one hand, t-BuONO is a potential active nitro radical source and can react with various functional groups. On the other hand, as a green and novel nitration reagent, t-BuONO has relatively low price and can easily produce a radical under mild conditions, which undoubtedly provides a simple and efficient way for nitration reactions. To date, some important reviews are available that summarize the synthesis of nitro compounds. To the best of our knowledge, however, there is still no review that exclusively discusses the synthesis of nitro compounds using t-BuONO through a radical strategy. Therefore, this review aims to highlight the recent advances in radical nitration using t-BuONO as nitration reagent. The main progress in this area has been presented according to the type of reaction substrates. Special attention has been paid discussion of the reaction mechanisms and selected examples of substrates have been given. We hope this paper will be a useful reference and inspiration for those who are exploring the synthesis of nitro compounds using t-BuONO.1 Introduction2 Radical Nitration of Alkenes3 Radical Nitration of Aromatics4 Radical Nitration of Alkynes5 Radical Nitration of 1,n-Enynes6 Radical Nitration of Alkanes7 Summary and Perspective

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Wade, Peter A., Nicholas Paparoidamis, C. Jared Miller, and Stephanie A. Costa. "Nitration reactions of conjugated compounds employing lithium nitrate and trifluoroacetic anhydride." Canadian Journal of Chemistry 97, no. 8 (August 2019): 591–96. http://dx.doi.org/10.1139/cjc-2019-0024.

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Tandem nitration and Ritter reaction of three conjugated dienes using trifluoroacetyl nitrate in acetonitrile led predominantly to 1,4-addition products and concomitant N-nitration. The major products, N-nitro-N-(4-nitrobut-2-enyl)acetamide derivatives, were obtained in 57%–70% yield. Tandem nitration and Ritter reaction of 4-methylpent-3-en-2-one led to the 1,2-addition product, a base-sensitive α-nitroketone. Nitration of N-methylacetamide and pyrrolidine by trifluoroacetyl nitrate occurs on the N-atom, whereas nitration of N-phenylacetamide occurs on the aromatic ring.

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35

Elias, Gracy, Bruce J. Mincher, Stephen P. Mezyk, Thomas D. Cullen, and Leigh R. Martin. "Anisole nitration during gamma-irradiation of aqueous nitrite and nitrate solutions: free radical versus ionic mechanisms." Environmental Chemistry 7, no. 2 (2010): 183. http://dx.doi.org/10.1071/en09109.

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Environmental context. The nitration of aromatic compounds is an important source of toxic, carcinogenic, and mutagenic species in the atmosphere. Gas phase nitration typically occurs by free radical reactions. Condensed-phase free radical reactions may also be relevant in fog and cloud water in polluted areas, in urban aerosols with low pH, in water treatment using advanced oxidation processes such as e-beam irradiation, and in nuclear waste treatment applications. This paper discusses research towards an improved understanding of nitration of aromatic compounds in the condensed phase under conditions conducive to free radical formation. Abstract. In the irradiated, acidic condensed phase, radiation-enhanced nitrous acid-catalysed, nitrosonium ion, electrophilic aromatic substitution followed by oxidation reactions dominated over radical addition reactions for anisole. This ionic mechanism would predominate in urban atmospheric aerosols and nuclear fuel dissolutions. Irradiated neutral nitrate anisole solutions were dominated by mixed nitrosonium/nitronium ion electrophilic aromatic substitution reactions, but with lower product yields. Solutions such as these might be encountered in water treatment by e-beam irradiation. Irradiation of neutral nitrite anisole solutions resulted in a statistical substitution pattern for nitroanisole products, suggesting non-electrophilic free radical reactions involving the •NO2 radical. Although often proposed as an atmospheric nitrating agent, NO2 radical is unlikely to have an important effect in the acidic condensed phase in the presence of more reactive, competing species such as nitrous acid.

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36

Adekunle, I. M. "Production of Cellulose Nitrate Polymer from Sawdust." E-Journal of Chemistry 7, no. 3 (2010): 709–16. http://dx.doi.org/10.1155/2010/807980.

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Cellulose nitrate polymer was produced from sawdust of Nigeria origin using a method, which involved alternate alkaline and chlorination treatment to remove non-cellulosic constituents, followed by nitration reaction. The effects of nitrating acid mixture type and composition, nitrating time and nitrating acid mixture to cellulose material ratio on yield and solubility of products were investigated. Results showed that alkaline resistant α -cellulose was extracted and the yield of cellulose nitrate ranged from 35.28 to 96.02%, increasing with acid mixtures HNO3+ AC2O + ACOH < HNO3+ H2SO4+ H2O < HNO3+ H3PO4+ H2O. Variation in the composition of a particular nitrating acid mixture, relative acid strength of the nitrating mixture, nitrating time and proportion of nitrating acid to cellulose material all influenced the yield and solubility of cellulose nitrate whose nitrogen contents ranged from 11.06 to 13.12%. The products were chloroform, acetone and ester soluble, hence, useful for industrial applications.

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Kulkarni, Amol A. "Continuous flow nitration in miniaturized devices." Beilstein Journal of Organic Chemistry 10 (February 14, 2014): 405–24. http://dx.doi.org/10.3762/bjoc.10.38.

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This review highlights the state of the art in the field of continuous flow nitration with miniaturized devices. Although nitration has been one of the oldest and most important unit reactions, the advent of miniaturized devices has paved the way for new opportunities to reconsider the conventional approach for exothermic and selectivity sensitive nitration reactions. Four different approaches to flow nitration with microreactors are presented herein and discussed in view of their advantages, limitations and applicability of the information towards scale-up. Selected recent patents that disclose scale-up methodologies for continuous flow nitration are also briefly reviewed.

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Glukhacheva, Vera S., Sergey G. Il’yasov, Elena O. Shestakova, Egor E. Zhukov, Dmitri S. Il’yasov, Anastasia A. Minakova, Ilia V. Eltsov, Andrey A. Nefedov, and Alexander M. Genaev. "Synthesis of Nitro- and Acetyl Derivatives of 3,7,10-Trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane." Materials 15, no. 23 (November 23, 2022): 8320. http://dx.doi.org/10.3390/ma15238320.

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Here, we report the study results of the nitration of 3,7,10-trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane (THAP) by different nitrating agents such as nitric acid, mixed nitric/sulfuric acids, nitric anhydride, and mixed concentrated nitric acid/acetic anhydride to furnish 3,7,10-trioxo-2-nitro-2,4,6,8,9,11-hexaaza[3.3.3]propellane and 3,7,10-trioxo-2,8-dinitro-2,4,6,8,9,11-hexaaza[3.3.3]propellane, whereas a lactam–lactim rearrangement was found to take place upon vigorous cooling to give 10-hydroxy-2,4,6,8,9,11-hexaazatricyclo[3.3.3.01,5]undec-9-ene-3,7-dione. The two competing reactions, lactam–lactim rearrangement, and nitration were found to take place. The acylation of 3,7,10-trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane was examined and the formation conditions of 2,6-di- and 2,6,9-triacetyl-substituted and 3,7,10-trioxo-2,4,6,8,9,11-hexaacetyl-2,4,6,8,9,11-hexaaza[3.3.3]propellane were established. The acetyl derivatives were found to be instable in an acidic medium and to undergo deacylation. The obtained findings correlate well with the quantum-chemical calculations.

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Kai, Wang, Bo Dong, Chao-fei Yang, and Hua Qian. "Acidic ionic liquids and green and recyclable catalysts in the clean nitration of TAIW to CL-20 using HNO3 electrolyte." Canadian Journal of Chemistry 95, no. 2 (February 2017): 190–93. http://dx.doi.org/10.1139/cjc-2016-0512.

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A novel method for the synthesis of CL-20 by nitration of TAIW was investigated. HNO3 electrolyte, containing generated dinitrogen pentoxide and unreacted dinitrogen tetraoxide, was directly used as a nitrating agent and the result was encouraging. A series of SO3H-functionalized ionic liquids were utilized to further improve the result. The satisfactory yield of CL-20 (94%) makes it a useful method for the green and clean synthesis of CL-20.

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Bodkhe, Arjun, Vilas Sudrik, Dnyaneshwar Karpe, and Shamrao Lawande. "Development of A Novel One-pot Process for the Synthesis of Tolcapone." Oriental Journal Of Chemistry 38, no. 6 (December 30, 2022): 1561–66. http://dx.doi.org/10.13005/ojc/380631.

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Novel one-pot process for the preparation of tolcapone., 2-methoxy anisole compound 9 treated with 4-methyl benzoyl chloride compound 10 using aluminium chloride gives 4-hydroxy -3-methoxy-4-methyl benzophenone compound 11 Further on nitration using new nitrating agent i.e. melamine nitrate to get corresponding nitro benzophenone compound 6. After demethylation using 48% HBr-Acetic acid to get pure Tolcapone 1 by the cost-effective and commercially feasible process.

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Putri, Reni, Robert Junaidi, and Mustain Mustain. "Pemanfaatan A-Selulosa Fiber Cake Kelapa Sawit Sebagai Alternatif Bahan Baku Nitroselulosa." Jurnal Pendidikan dan Teknologi Indonesia 1, no. 9 (September 26, 2021): 351–56. http://dx.doi.org/10.52436/1.jpti.83.

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Dengan kadar selulosa yang tinggi, fiber cake kelapa sawit dapat digunakan sebagai bahan baku pembuatan nitroselulosa. Percobaan ini bertujuan untuk menghasilkan nitroselulosa dari ?-Selulosa fiber cake kelapa sawit yang memiliki yield produk dan kadar nitrogen yang tinggi dengan waktu yang singkat. Percobaan dilakukan melalui tiga tahapan yaitu tahap pre-treatment bahan baku, tahap pembuatan nitroselulosa melalui proses nitrasi dan tahap analisis produk nitroselulosa. Konversi ?-selulosa fiber cake kelapa sawit menjadi nitroselulosa dilakukan dengan variasi asam penitrasi dengan perbandingan H2SO4 98% dengan HNO3 70% sebesar 1:1, 1:2, 1:3, 1:4 dan 1:5, waktu reaksi pada proses nitrasi selama 30 dan 40 menit serta variasi.suhu proses nitrasi 10-15oC dan 15-20oC. Dari hasil penelitian diketahui bahwa kondisi optimal proses pembuatan nitroselulosa dari fiber cake kelapa sawit dicapai pada rasio asam penitrasi sebesar 1:1 dengan suhu nitrasi 15-20oC dan waktu nitrasi selama 40 menit. Pada kondisi ini diperoleh yield sebesar 95,0% dengan kadar nitrogen sebesar 9,9%. With high cellulose content, fiber cake palm oil can be used as a raw material for the manufacture of nitrocellulose. This experiment aims to produce nitrocellulose from fiber cake palm oil which has high yield product and high nitrogen content. The experiment was carried out in three stages, namely the pre-treatment of raw materials, the stage of making nitrocellulose through the nitration process and the analysis stage of the nitrocellulose product. The conversion of ?-cellulose fiber cake into nitrocellulose was carried out by varying the acid nitrate with a ratio of H2SO4 98% with HNO3 70% at 1:1, 1:2, 1:3, 1:4 and 1:5, The reaction is in the nitration process for 30 and 40 minutes and the variation of the nitration process temperature is 10-15oC and 15-20oC. From the results of the study it is known that the optimal conditions for the process of making nitrocellulose from fiber cake palm oil are achieved at a nitrating acid ratio of 1 :1 with a nitration temperature of 15-20oC and a nitration time of 40 minutes. In this condition, yield of 95,0% was obtained with nitrogen content of 9,9%.

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Алимов, А. Р., В. А. Петров, В. Ф. Мадякин, and А. Б. Лившиц. "INTENSIFICATION OF THE DIFFUSION STAGE OF CELLULOSE NITRATION." Южно-Сибирский научный вестник, no. 5(45) (October 31, 2022): 63–69. http://dx.doi.org/10.25699/sssb.2022.45.5.004.

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Повышение эффективности технологии и качества нитратов целлюлозы является актуальной задачей в настоящее время. Одним из направлений повышения эффективности является интенсификация отдельных стадий технологического процесса с помощью различных физических и физико-химических воздействий. В данной работе представлены результаты исследования интенсификации диффузионной стадии нитрования целлюлозы термо-вакуум-импульсным методом. Для синтеза нитратов целлюлозы (НЦ) использовали хлопковую целлюлозу марки 35 (ГОСТ 595-79) и штатную нитрующую кислотную смесь (НКС), применяемую для получения низкоазотных НЦ следующего состава HNO3-23,60%; H2O-16,81%; H2SO4 -59,59%. Увеличение скорости диффузии нитрующих кислотных смесей вглубь целлюлозного волокна осуществляли за счет использования активированной термо-вакуум-импульсным воздействием целлюлозы, предварительного вакуумирования капиллярно-пористого пространства целлюлозы и импульсной (за счет градиента давления ∆P = 99,325 кПа) подачи нитрующей кислотной смеси в реакционную зону. В работе представлена экспериментальная установка вакуум-импульсного нитрования целлюлозы и принцип ее действия. На основе гидродинамической модели определены оптимальные глубина вакуумирования и высота слоя целлюлозы при проведении процесса. Приведено сравнение кинетических кривых, полученных при вакуум-импульсном и штатном способах нитрования целлюлозы. Показано, что время, за которое содержание азота в НЦ достигает 190,0 млNO/г при вакуум-импульсном способе в 5 раз меньше, чем при штатном. Кроме того, экспериментально получена зависимость содержания азота в нитрате целлюлозы от температуры нитрующей кислотной смеси при исследуемом способе. Также в статье представлен анализ полученных образцов нитратов целлюлозы по основным физико-химическим характеристикам: содержание азота, растворимость, относительной вязкость раствора, химическая стойкость. Полученные характеристики образцов НЦ соответствуют ГОСТу на лаковые коллоксилины, что дает основание продолжить исследования в данном направлении. Improving the efficiency of technology and the quality of cellulose nitrates is an urgent task at the present time. One of the ways to improve efficiency is the intensification of individual stages of the technological process with the help of various physical and physico-chemical effects. This paper presents the results of a study of the intensification of the diffusion stage of cellulose nitration by the thermal-vacuum-pulse method. For the synthesis of cellulose nitrates (NC), we used cotton cellulose grade 35 (GOST 595-79) and a standard nitrating acid mixture (NAM) used to obtain low-nitrogen NC of the following composition HNO3-23,60%; H2O-16,81%; H2SO4 -59,59%. The increase in the rate of diffusion of nitrating acid mixtures deep into the cellulose fiber was carried out by using cellulose activated by thermal-vacuum-pulse action, preliminary evacuation of the capillary-porous media of cellulose, and pulsed (due to a pressure gradient ∆P = 99.325 kPa) input of a nitrating acid mixture into the reaction zone. The paper presents an experimental set for vacuum-pulse nitration of cellulose and the principle of its operation. Based on the hydrodynamic model, the optimal evacuation depth and the height of the cellulose layer during the process were determined. A comparison is made of the kinetic curves obtained with the vacuum-pulse and standard methods of cellulose nitration. It is shown that the time during which the nitrogen content in the NC reaches 190.0 mlNO/g with the vacuum-pulse method is 5 times less than with the standard one. In addition, the dependence of the nitrogen content in cellulose nitrate on the temperature of the nitrating acid mixture was experimentally obtained for the method under study. The article also presents an analysis of the obtained samples of cellulose nitrates according to the main physical and chemical characteristics: nitrogen content, solubility, relative viscosity of the solution, chemical resistance. The obtained characteristics of NC samples correspond to GOST for lacquer colloxylins, which gives reason to continue research in this direction.

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Bellamy, Anthony J., Nikolaj V. Latypov, and Patrick Goede. "Nitration of the 6-Methyl-1,3,5-Triazine Derivatives, 6-Methyl-1,3,5-Triazine-2,4(1H, 3H)-Dione and 2,4-Dimethoxy-6-Methyl-1,3,5-Triazine." Journal of Chemical Research 2003, no. 9 (September 2003): 529–30. http://dx.doi.org/10.3184/030823403322597171.

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Nitration of 6-methyl-1,3,5-triazine-2,4(1 H, 3 H)-dione (III) gave 2,4,6-trihydroxy-1,3,5-triazine (cyanuric acid, V) and tetranitromethane, whilst nitration of 2,4-dimethoxy-6-methyl-1,3,5-triazine (IV) gave 2,4-dimethoxy-6-trinitromethyl-1,3,5-triazine (VII) or a furazan N-oxide derivative (IX), depending upon the nitration medium.

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Ion, Laura, Ancuta-Veronica Lupaescu, Andrei Neamtu, Gabi Drochioiu, and Brindusa-Alina Petre. "Binding Affinities Studies of Nitrated Model Peptides to Monoclonal Anti-3-nitrotyrosine Antibody." Revista de Chimie 71, no. 1 (February 7, 2020): 259–65. http://dx.doi.org/10.37358/rc.20.1.7843.

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Tyrosine nitration has been shown to be an important oxidative protein modification and play a crucial role in pathophysiological conditions, associated with oxidative stress, such as atherosclerosis and neurodegenerative disease. For a better understanding of nitration mechanism, the identification and the quantification of nitration sites represents an important research goal. Due to (i) the low levels of nitration in native proteins, (ii) structural changes induced by nitration and (iii) the specificity of anti � 3 nitro tyrosine antibodies the method which may provide the identification of nitration sites in proteins represent a challenging experimental task. In this work we have used synthetic nitrated tyrosine containing peptides to determine antibody-binding affinities and specificity of different tyrosine residue (Tyr33, Tyr98, Tyr107and Tyr122) in Eosinophil cationic proteins (ECP). The highest affinity of nitrated ECP peptides to the monoclonal antibody (anti-3NT) was obtained for the only in vivo nitrated identified residue Tyr33(0.082 �M); in contrast, all other three nitrated residues at Tyr98, Tyr107 and Tyr122) showed significant lower affinity being imbedded in the ECP protein structure as similar resulted by molecular computational modeling.

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Fischer, Alfred, Deborah L. Fyles, George N. Henderson, and Sumit Ray Mahasay. "ipso Nitration. XXVIII. Nitration of 4-substituted toluenes: 1,2 adducts." Canadian Journal of Chemistry 64, no. 9 (September 1, 1986): 1764–70. http://dx.doi.org/10.1139/v86-291.

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Nitration of 4-acetamido-, 4-chloro-, and 4-methoxy-toluene in acetic anhydride gives in each case a cis 1,2 nitronium acetate adduct in addition to the nitro substitution product(s). Nitration of 4-fluorotoluene gives a pair of diastereomeric 1,4 nitronium acetate adducts and the cis 1,2 adduct.

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46

Rastuti, Undri, Jumina Jumina, and Sabirin Matsjeh. "SINTESIS 6-NITRO VERATRALDEHID (3,4-DIMETOKSI-6-NITRO BENZALDEHID) DARI VANILIN DENGAN HNO3 DAN CAMPURAN HNO3-H2SO4." Molekul 4, no. 2 (November 1, 2009): 62. http://dx.doi.org/10.20884/1.jm.2009.4.2.64.

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The synthesis of 6-nitro veratraldehyde from vanillin was used HNO3 and a mixture of HNO3 and H2SO4. The reaction steps were (I) methylation of vanillin and (2) nitration of the methylation product. Methylation of vanillin was conducted using dimetnylsulfate and NaOH at 60 0C for 2 hours. Nitration of the methylation product was performed in two methods, which using HN03 and using a mixture of HN03 and H2SO4 both at 5 0C for 2 hours. The products were analyzed by means of TLC, GC; IR, 1H-NMR and GC-MS spectrometers.The methylation of vanillin gave 87.7 % yield of veratraldehyde which was found as a white crystal (m.p 43 oC). The nitration of veratraldehyde produced 6-nitro veratraldehyde observed as a yellow crystal having of m.p. 1300C. Nitration using neat HNO3 gave a smaller yield (50.35%) of 6-nitro veratraldehyde than nitration with a mixture of HNO3 and H2SO4 (93.63 %).

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47

Corpas, Francisco J., Mounira Chaki, Marina Leterrier, and Juan B. Barroso. "Protein tyrosine nitration." Plant Signaling & Behavior 4, no. 10 (October 2009): 920–23. http://dx.doi.org/10.4161/psb.4.10.9466.

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SMITH, A. "Nitration immunology*1." Journal of Allergy and Clinical Immunology 113, no. 2 (February 2004): S51. http://dx.doi.org/10.1016/j.jaci.2003.12.148.

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Turaev, A. S., and E. N. Yanishevskaya. "Nitration of carboxymethylcellulose." Chemistry of Natural Compounds 30, no. 4 (July 1994): 502–4. http://dx.doi.org/10.1007/bf00630410.

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Kopranenkov, V. N., E. A. Makarova, and E. A. Luk'yanets. "Nitration of tetrabenzoporphins." Chemistry of Heterocyclic Compounds 22, no. 9 (September 1986): 960–64. http://dx.doi.org/10.1007/bf00478125.

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Journal articles on the topic 'Nitration'

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