Academic literature on the topic 'Amido selenide'
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Journal articles on the topic "Amido selenide"
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Poluboyarinov, P. A., D. G. Elistratov, and V. I. Shvets. "METABOLISM AND MECHANISM OF TOXICITY OF SELENIUM-CONTAINING SUPPLEMENTS USED FOR OPTIMIZING HUMAN SELENIUM STATUS." Fine Chemical Technologies 14, no. 1 (February 28, 2019): 5–24. http://dx.doi.org/10.32362/2410-6593-2019-14-1-5-24.
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The work presents a review devoted to the metabolism and the mechanism of toxicity of seleniumcontaining supplements: elemental selenium, sodium selenite, diacetophenonyl selenide, selenopyrane, ebselen, dimethyl dipyrasolyl selenide and selenium-containing amino acids used for correction of selenium deficiency. Elemental selenium penetrating through cell walls, but not through transport channels demonstrates poorly predicted and difficultly regulated bioavailability. Sodium selenate is known to be the most toxic form of selenium in food. The metabolism of xenobiotic diacetophenonyl selenide resembles that of sodium selenide. The xenobiotic reacts with thiols, for instance, with the reduced form of glutathione leading to the formation of hydrogen selenide. Ebselen is not considered to be a well bioavailable form of selenium and thus possesses low toxicity. Xenobiotic selenopyrane eliminates selenium only in processes of xenobiotic liver exchange, and in our investigations - partially in acid-catalyzed hydrolysis. The metabolism of xenobiotic dimethyl dipyrasolyl selenide having low toxicity is poorly investigated. The toxicity of high doses of selenomethionine is determined by the possibility of incorporation in proteins and vitally important enzymes with dramatic changes of protein quaternary structure. The toxicity of high doses of methylselenocysteine seems to be caused by the lack of an exchange pool in the body and quick regeneration of hydrogen selenide from methylselenol which is formed as a result of enzymatic destruction of this amino acid. Also the issue of the most prospect selenium donor is discussed. The physiological compatibility, the low toxicity, the presence of an exchangeable pool in the organism, the antioxidantal properties and the simplicity of production indicate selenocystine as an optimal selenium donor.
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Sonet, Jordan, Maurine Mosca, Katarzyna Bierla, Karolina Modzelewska, Anna Flis-Borsuk, Piotr Suchocki, Iza Ksiazek, et al. "Selenized Plant Oil Is an Efficient Source of Selenium for Selenoprotein Biosynthesis in Human Cell Lines." Nutrients 11, no. 7 (July 4, 2019): 1524. http://dx.doi.org/10.3390/nu11071524.
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Selenium is an essential trace element which is incorporated in the form of a rare amino acid, the selenocysteine, into an important group of proteins, the selenoproteins. Among the twenty-five selenoprotein genes identified to date, several have important cellular functions in antioxidant defense, cell signaling and redox homeostasis. Many selenoproteins are regulated by the availability of selenium which mostly occurs in the form of water-soluble molecules, either organic (selenomethionine, selenocysteine, and selenoproteins) or inorganic (selenate or selenite). Recently, a mixture of selenitriglycerides, obtained by the reaction of selenite with sunflower oil at high temperature, referred to as Selol, was proposed as a novel non-toxic, highly bioavailable and active antioxidant and antineoplastic agent. Free selenite is not present in the final product since the two phases (water soluble and oil) are separated and the residual water-soluble selenite discarded. Here we compare the assimilation of selenium as Selol, selenite and selenate by various cancerous (LNCaP) or immortalized (HEK293 and PNT1A) cell lines. An approach combining analytical chemistry, molecular biology and biochemistry demonstrated that selenium from Selol was efficiently incorporated in selenoproteins in human cell lines, and thus produced the first ever evidence of the bioavailability of selenium from selenized lipids.
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Chao, Wei, Shen Rao, Qiangwen Chen, Weiwei Zhang, Yongling Liao, Jiabao Ye, Shuiyuan Cheng, Xiaoyan Yang, and Feng Xu. "Advances in Research on the Involvement of Selenium in Regulating Plant Ecosystems." Plants 11, no. 20 (October 14, 2022): 2712. http://dx.doi.org/10.3390/plants11202712.
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Selenium is an essential trace element which plays an important role in human immune regulation and disease prevention. Plants absorb inorganic selenium (selenite or selenate) from the soil and convert it into various organic selenides (such as seleno amino acids, selenoproteins, and volatile selenides) via the sulfur metabolic pathway. These organic selenides are important sources of dietary selenium supplementation for humans. Organoselenides can promote plant growth, improve nutritional quality, and play an important regulatory function in plant ecosystems. The release of selenium-containing compounds into the soil by Se hyperaccumulators can promote the growth of Se accumulators but inhibit the growth and distribution of non-Se accumulators. Volatile selenides with specific odors have a deterrent effect on herbivores, reducing their feeding on plants. Soil microorganisms can effectively promote the uptake and transformation of selenium in plants, and organic selenides in plants can improve the tolerance of plants to pathogenic bacteria. Although selenium is not an essential trace element for plants, the right amount of selenium has important physiological and ecological benefits for them. This review summarizes recent research related to the functions of selenium in plant ecosystems to provide a deeper understanding of the significance of this element in plant physiology and ecosystems and to serve as a theoretical basis and technical support for the full exploitation and rational application of the ecological functions of selenium-accumulating plants.
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Eswayah, Abdurrahman S., Thomas J. Smith, and Philip H. E. Gardiner. "Microbial Transformations of Selenium Species of Relevance to Bioremediation." Applied and Environmental Microbiology 82, no. 16 (June 3, 2016): 4848–59. http://dx.doi.org/10.1128/aem.00877-16.
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ABSTRACTSelenium species, particularly the oxyanions selenite (SeO32−) and selenate (SeO42−), are significant pollutants in the environment that leach from rocks and are released by anthropogenic activities. Selenium is also an essential micronutrient for organisms across the tree of life, including microorganisms and human beings, particularly because of its presence in the 21st genetically encoded amino acid, selenocysteine. Environmental microorganisms are known to be capable of a range of transformations of selenium species, including reduction, methylation, oxidation, and demethylation. Assimilatory reduction of selenium species is necessary for the synthesis of selenoproteins. Dissimilatory reduction of selenate is known to support the anaerobic respiration of a number of microorganisms, and the dissimilatory reduction of soluble selenate and selenite to nanoparticulate elemental selenium greatly reduces the toxicity and bioavailability of selenium and has a major role in bioremediation and potentially in the production of selenium nanospheres for technological applications. Also, microbial methylation after reduction of Se oxyanions is another potentially effective detoxification process if limitations with low reaction rates and capture of the volatile methylated selenium species can be overcome. This review discusses microbial transformations of different forms of Se in an environmental context, with special emphasis on bioremediation of Se pollution.
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Potapov, Vladimir A., Mikhail V. Andreev, Maxim V. Musalov, Irina V. Sterkhova, Svetlana V. Amosova, and Lyudmila I. Larina. "Regio- and Stereoselective Synthesis of (Z,Z)-Bis(3-amino-3-oxo-1-propenyl) Selenides and Diselenides Based on 2-propynamides: A Novel Family of Diselenides with High Glutathione Peroxidase-like Activity." Inorganics 10, no. 6 (May 30, 2022): 74. http://dx.doi.org/10.3390/inorganics10060074.
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The efficient regio- and stereoselective syntheses of (Z,Z)-bis(3-amino-3-oxo-1-propenyl) selenides and diselenides in high yields based on the nucleophilic addition of sodium selenide to 2-propynamides and sodium diselenide to 3-(trimethylsilyl)-2-propynamides have been developed. The first examples of the addition of a selenium-centered nucleophile to 2-propynamides with a terminal triple bond and diselenide anion to 3-(trimethylsilyl)-2-propynamides have been carried out. Bis(3-amino-3-oxo-1-propenyl) diselenides are a novel family of compounds, none of which has yet been described in the literature. The glutathione peroxidase-like activity of the obtained compounds has been evaluated and products with high activity have been found. It was established that diselenides are superior to selenides with the same substituents in glutathione peroxidase-like activity. The results of the structural studying of products by single-crystal X-ray diffraction analysis and 77Se-NMR data are discussed.
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MB, Reddy. "Assessing the Bioavailability and Bioaccessibility of Selenium from Selenium-Rich Algae." Food Science & Nutrition Technology 5, no. 5 (September 30, 2020): 1–9. http://dx.doi.org/10.23880/fsnt-16000228.
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Many new selenium (Se) sources for supplementation use are emerging. The objective of this study was to test the Se bioaccessibility (BAC) and bioavailability (BA) of Se-rich algae. Algal samples were cultivated in media containing selenite or selenate then BAC and BA were compared to Se-salts and Se-amino acids from traditional supplementation. BAC was tested based on the Se solubility post in vitro digestion and BA by induction of cellular glutathione peroxidase activity (GPx) in a Se deficient Caco-2 cell model. Cells treated with algae grown in selenate and selenite had a mean GPx activity that was significantly less than the SeMet treatment (P<0.05). Overall, no algae samples grown in selenite were identified as superior since no significant differences were found among the algae samples. However, the algae grown in the higher concentration of selenate (200 ppm) with no sulfite appeared to have a better BA than all other algae samples. Although Se-rich algae did not increase GPx activity as well as traditional supplementation forms, the results gave an insight for the ways to improve Se BA from this novel source. In addition, evaluation of nutritional profile of the algae will give us a greater understanding of how it can offer other health benefits for future supplementation.
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Wegner, Gerald L., Alexander Jockisch, Annette Schier, and Hubert Schmidbaur. "Crystal and Molecular Structures of the Sulfurization and Selenation Products of Bis[bis(trimethylsilyl)amino]germanium(II). Crystal Structure of (Triphenylphosphine)gold(I) Bis(trimethylsilyl)amide." Zeitschrift für Naturforschung B 55, no. 5 (May 1, 2000): 347–51. http://dx.doi.org/10.1515/znb-2000-0501.
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Treatment of bis[bis(trimethylsilyl)amino]germanium(II) with elemental sulfur or selenium affords high yields of the corresponding monosulfide [(Me3Si)2N]2GeS and selenide [(Me3Si)2N]2GeSe, respectively. The crystalline products have now been shown to be cyclic dimers with (GeS/Se)2 four-membered rings by X-ray single crystal structure analysis. The crystal structure of (triphenylphosphine)gold(I) bis(trimethylsilyl)amide (Ph3P)Au-N(SiMe3)2 has also been determined. The molecule is a monomer with a tricoordinate nitrogen atom in a planar configuration [Si2NAu]. The compound does not undergo insertion of the bis[bis(trimethylsilyl)amino]germylene.
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Nasim, Muhammad Jawad, Mhd Mouayad Zuraik, Ahmad Yaman Abdin, Yannick Ney, and Claus Jacob. "Selenomethionine: A Pink Trojan Redox Horse with Implications in Aging and Various Age-Related Diseases." Antioxidants 10, no. 6 (May 31, 2021): 882. http://dx.doi.org/10.3390/antiox10060882.
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Selenium is an essential trace element. Although this chalcogen forms a wide variety of compounds, there are surprisingly few small-molecule organic selenium compounds (OSeCs) in biology. Besides its more prominent relative selenocysteine (SeCys), the amino acid selenomethionine (SeMet) is one example. SeMet is synthesized in plants and some fungi and, via nutrition, finds its way into mammalian cells. In contrast to its sulfur analog methionine (Met), SeMet is extraordinarily redox active under physiological conditions and via its catalytic selenide (RSeR’)/selenoxide (RSe(O)R’) couple provides protection against reactive oxygen species (ROS) and other possibly harmful oxidants. In contrast to SeCys, which is incorporated via an eloquent ribosomal mechanism, SeMet can enter such biomolecules by simply replacing proteinogenic Met. Interestingly, eukaryotes, such as yeast and mammals, also metabolize SeMet to a small family of reactive selenium species (RSeS). Together, SeMet, proteins containing SeMet and metabolites of SeMet form a powerful triad of redox-active metabolites with a plethora of biological implications. In any case, SeMet and its family of natural RSeS provide plenty of opportunities for studies in the fields of nutrition, aging, health and redox biology.
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SUN, Mu-fang, Jing-jing WANG, Wei LIU, Peng YIN, Gui-yi GUO, Cui-ling TONG, and Ya-li CHANG. "Effect and mechanism of exogenous selenium on selenium content and quality of fresh tea leaves." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 50, no. 3 (September 6, 2022): 12814. http://dx.doi.org/10.15835/nbha50312814.
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To study the effect and mechanism of selenium sources on the selenium content and quality of fresh tea leaves, tea seedlings (Camellia sinensis (L.) O. Kuntze) were the research object. A solution of 100 mg/L sodium selenate (Na2SeO4), sodium selenite (Na2SeO3), and selenium yeast (selenium yeast) were applied on the leaves surface of 5-week-old tea plants, and the selenium levels in the leaves, roots, and stems were determined at 20 weeks of age. The effects of different selenium sources on the mineral nutrient content, antioxidant enzyme activity, and quality parameters content in leaves were analyzed. The mechanism was analyzed by detecting the expression levels of related genes. The results showed that the three selenium sources can increase the growth of tea seedlings and the selenium content in leaves and stems, and the selenium yeast treatment had the most significant effect. Selenium spraying promoted the absorption of mineral nutrients such as nitrogen, phosphorus, and potassium, but had no significant impact on the absorption of calcium and magnesium. Spraying the three selenium sources dramatically increased the activities of APX, POD, and SOD antioxidant enzymes, among which the selenium yeast treatment had the most significant effect. However, there was no significant impact on the MDA level in this study. Selenium sources markedly increased leaves total amino acid levels, accompanied by up-regulation the genes of amino acid synthetic enzymes (CsGS, CsGOGAT, and CsGDH). Leaves glucose, tea polyphenol, total soluble protein, catechin, flavonoid contents, and sucrose were higher in selenium sources treatments than in control treatment seedlings. Moreover, selenium sources up-regulated expression of CsHMGR, CsAPX, and CsTCS1 genes. selenium yeast had the best comprehensive effect of the three selenium sources. These results confirmed that selenium sources play a positive role on the selenium content and quality of tea by increasing the antioxidant capacity of leaves, the absorption rate of mineral nutrients, and regulating expression of related genes in Camellia sinensis.
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Seale, Lucia A., Vedbar S. Khadka, Mark Menor, Guoxiang Xie, Ligia M. Watanabe, Alexandru Sasuclark, Kyrillos Guirguis, et al. "Combined Omics Reveals That Disruption of the Selenocysteine Lyase Gene Affects Amino Acid Pathways in Mice." Nutrients 11, no. 11 (October 26, 2019): 2584. http://dx.doi.org/10.3390/nu11112584.
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Selenium is a nonmetal trace element that is critical for several redox reactions and utilized to produce the amino acid selenocysteine (Sec), which can be incorporated into selenoproteins. Selenocysteine lyase (SCL) is an enzyme which decomposes Sec into selenide and alanine, releasing the selenide to be further utilized to synthesize new selenoproteins. Disruption of the selenocysteine lyase gene (Scly) in mice (Scly−/− or Scly KO) led to obesity with dyslipidemia, hyperinsulinemia, glucose intolerance and lipid accumulation in the hepatocytes. As the liver is a central regulator of glucose and lipid homeostasis, as well as selenium metabolism, we aimed to pinpoint hepatic molecular pathways affected by the Scly gene disruption. Using RNA sequencing and metabolomics, we identified differentially expressed genes and metabolites in the livers of Scly KO mice. Integrated omics revealed that biological pathways related to amino acid metabolism, particularly alanine and glycine metabolism, were affected in the liver by disruption of Scly in mice with selenium adequacy. We further confirmed that hepatic glycine levels are elevated in male, but not in female, Scly KO mice. In conclusion, our results reveal that Scly participates in the modulation of hepatic amino acid metabolic pathways.
Dissertations / Theses on the topic "Amido selenide"
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Silva, Alexandre Vieira. "Síntese de organo-seleno aminas e sua resolução cinética via reação de acetilação enantiosseletiva mediada por lipases." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/46/46135/tde-02072008-125408/.
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Nesse trabalho foi desenvolvido um método de síntese quimioenzimática de organo-seleno aminas (1-((2, 3 ou 4 selenocianato)fenil)etanonas) e amidas (N-(1-(2, 3 ou 4-(etilseleno)fenil)etil)acetamida) enantiomericamente enriquecidas. Inicialmente, as organo-seleno aminas, na forma racêmica, foram sintetizadas a partir das orto-, meta- e para- aminoacetofenonas. A incorporação do átomo de selênio nas cetonas aromáticas foi realizada através da reação de selenocianato de potássio com sais de diazônio, preparados a partir das aminoacetofenonas, para levar as o, m ou p-selenocianato acetofenonas (28-65 %). Reações desses compostos com NaBH4, formaram os intermediários organo-selenoboro, que foram posteriormente alquilados com haletos de alquila de modo a formar as organo-seleno acetofenonas (1-(2, 3 ou 4-(etilseleno)fenil)etanona) (63-78 %). As Organo-seleno aminas racêmicas foram preparadas por aminação redutiva das cetonas correspondentes (39-73 %). Após desenvolvido o protocolo de síntese das organo-seleno aminas, nós estudamos a resolução cinética desses compostos através de reação de acetilação mediada por lipases. Um estudo inicial foi conduzido com a amina para substituído, como substrato modelo, de modo a buscar a lipase, solvente, temperatura, razão lipase/substrato e acilante apropriados para a resolução cinética. De acordo com os resultados obtidos, as condições ideais para se conduzir a resolução cinética foi CAL-B como biocatalisador, hexano como solvente e acetato de etila ou metóxi-acetato de etila como acilante a 30°C. Utilizando esse protocolo, as organo-seleno amidas foram preparadas com excelentes excessos enantioméricos (99 %).In this work, we have developed a chemoenzymatic method to enantiomerically synthesize enriched organoselenium amines (1-(2, 3 or 4 -(ethylselanyl)phenyl)ethanamine) and amides (N-(1-(2, 3 or 4-(ethylselanyl)phenyl)ethyl)acetamide). Initially, the organoselenium amines, in the racemic form, were synthesized from ortho-, meta- and para- aminoacetophenones. The incorporation of the selenium atom into the aromatic ketones was achieved by the use of reaction of potassium selenocyanate and diazonium salts, prepared from aminoacetophenones, to afford selenocyanate acetophenones (28-65 %). These compounds were alkylated with alkyl halide to yield the organoselenium acetophenones (1-(2, 3 or 4-(ethylselanyl)phenyl)ethanone) (63-78 %) which were converted into their corresponding racemic organoselenium amines by reductive amination (39-73 %). After developing the protocol for the synthesis of racemic organoselenium amines, we studied the kinetic resolution of these compounds by their acetylation mediated by lipases. An initial study was carried out with the organoselenium amine para substituted, as a model substrate, in order to screen for appropriate lipase, solvent, temperature, lipase/substrate ratio and acylant. This study showed that the ideal condition to conduct the kinetic resolution was CAL-B as biocatalyst, hexane as solvent and ethyl acetate or ethyl methoxyacetate as acylant at 30°C. By using this protocol, the organoselenium amides were prepared in excellent enantiomeric excess (99 %).
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Gaul, David Allen. "Synthetic, mechanistic, structural, and dynamic NMR investigations of zinc bis(amide) compounds." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/30741.
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Robey, Stephanie. "Reactions of Platinum(II) Compounds with Selenium Containing Amino Acids." TopSCHOLAR®, 2013. http://digitalcommons.wku.edu/theses/1252.
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Platinum(II) anticancer medications essentially react with DNA forming kinks inthe double helix of DNA and causing apoptosis. It has also been noted that theseanticancer medications react with methionine and cysteine in the body. With the new discoveries of selenium containing amino acids including selenomethionine and selenocysteine, new research is ongoing to see what types of products can be formed from these amino acids. Our research reacts [Pt(Met-S,N)Cl2] 2+ with selenomethionine to determine what types of products are produced. Monochelates including [Pt(SeMet-Se,N)Cl2] 2+ have formed two isomers, as well as other products that insinuate both selenomethionine and methionine binding with the platinum to form various [Pt(SeMet- Se,N)(Met-S,N)]2+ products. When initially reacting 6 mM [Pt(Met-S,N)Cl2] 2+ with 3 mM SeMet, the monochelates of both are produced without forming any free methionine which would suggest that there is free platinum in our solution creating the SeMet monochelate. When adding additional SeMet to the solution the same products are formed that are created when reacting 6 mM [Pt(Met-S,N)Cl2] 2+ and 6 mM SeMet. The 1H NMR spectrum for these products imply a product of [Pt(SeMet-Se,N)(Met-S,N)] 2+. Also, reactions with [Pt(en)(ox)] 2+ and SeMet were conducted and produced various products at two different pH’s. A [Pt(SeMet-Se,N2] 2+ product was formed at lower pH and produced free ethylenediamine, however at a higher pH only [Pt(en)(SeMet-Se,N)]2+ was produced.
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Wan, Lili. "Determination of total selenium and seleno-amino acids in yeast and aquatic organisms by liquid chromatography and inductively coupled plasma mass spectrometry." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4683.
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Thesis (Ph. D.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 4, 2008) Vita. Includes bibliographical references.
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Papp, Laura V., and n/a. "Multiple Levels of Regulation of Human SECIS Binding Protein 2, SBP2." Griffith University. School of Biomolecular and Biomedical Science, 2006. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20070208.145623.
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Selenium is an essential trace mineral of fundamental importance to human health. Its beneficial functions are largely attributed to its presence within a group of proteins named selenoproteins in the form of the amino acid selenocysteine (Sec). Recently, it was revealed that the human selenoproteome consists of 25 selenoproteins, and for many of them their function remains unknown. The most prominent known roles of selenoproteins are to maintain the intracellular redox homeostasis, redox regulation of intracellular signalling and thyroid hormone metabolism. Sec incorporation into selenoproteins employs a unique mechanism that involves decoding of the UGA stop codon. The process requires interplay between distinct, intrinsic features such as the Sec Insertion Sequence (SECIS) element, the tRNASec and multiple protein factors. The work presented in this thesis has focused on characterising the regulation of human SECIS binding protein 2, SBP2, a factor central to this process. Experimental approaches combined with bioinformatics analysis revealed that SBP2 is subjected to alternative splicing. A total of nine alternatively spliced transcripts appear to be expressed in cells, potentially encoding five different protein isoforms. The alternative splicing events are restricted to the 5?-region, which is proposed to be dispensable for Sec incorporation. One of the variants identified, contains a mitochondrial targeting sequence that was capable of targetting SBP2 into the mitochondrial compartment. This isoform also appears to be expressed endogenously within the mitochondria in cells. Previous reports have depicted SBP2 as a ribosomal protein, despite the presence of a putative Nuclear Localisation Signal (NLS). In this study it was found that SBP2 subcellular localisation is not restricted to ribosomes. Intrinsic functional NLS and Nuclear Export Signals (NESs), enable SBP2 to shuttle between the nucleus and the cytoplasm via the CRM1 pathway. In addition, the subcellular localisation of SBP2 appears to play an important role in regulating Sec incorporation into selenoproteins. The subcellular localisation of SBP2 is altered by conditions imposing oxidative stress. Several oxidising agents induce the nuclear accumulation of SBP2, which occurs via oxidation of cysteine residues within a novel redox-sensitive cysteine rich domain (CRD). Cysteine residues were to form disulfide bonds and glutathione-mixed disulfides during oxidising conditions, which are efficiently reversed in vitro by the thioredoxin and glutaredoxin systems, respectively. These modifications negatively regulate selenoprotein synthesis. Cells depleted of SBP2 are more sensitive to oxidative stress than control cells, which correlated with a substantial decrease in selenoprotein synthesis after treatment with oxidising agents. These results provide direct evidence that SBP2 is required for Sec incorporation in vivo and suggest that nuclear sequestration of SBP2 under such conditions may represent a mechanism to regulate the expression of selenoproteins. Collectively, these results suggest that SBP2 is regulated at multiple levels: by alternative splicing, changes in subcellar localisation and redox control.
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DeSilva, Veronica. "Selenium redox cycling isolation and characterization of a stimulatory component from tissue of loblolly pine for multiplication of somatic embryos; development of an assay to measure l-phenylalanine concentration in blood plasma /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/29788.
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Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2007.Committee Chair: Sheldon May; Committee Members: Nicholas Hud, Stanley Pollock, James Powers, and Gerald Pullman. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Sá, Fabiano Cesar [UNESP]. "Energia mecânica, energia térmica e moagem na extrusão de alimentos para cães e gatos." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/126533.
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000835580.pdf: 2655261 bytes, checksum: e7af4bb36dc30d671baadb257d339877 (MD5)A eficiência do processo de extrusão está diretamente relacionada à energia total transferida para a massa de ração. Extrusoras de rosca simples usualmente implementam ao redor de 20kWh/ton de energia mecânica específica (EME), mas menos se conhece à respeito da implementação de energia térmica específica (ETE) e das implicações da relação entre ETE:EME no processamento de alimentos para cães e gatos. O presente estudo avaliou os efeitos da implementação de três relações entre ETE:EME sobre a macroestrutura dos estrusados, gelatinização do amido, perda de nutrientes, digestibilidade dos nutrientes e palatabilidade de alimentos para cães e gatos. Para cada espécie, o experimento incluiu uma formulação processada de modo a se obter 3 relações ETE:EME, totalizando 3 dietas por espécie. A digestibilidade dos nutrientes foi estudada com 18 cães ou 18 gatos, pelo método de coleta total de fezes. A palatabilidade das dietas foi comparada pelo método de duas vasilhas, com no mínimo 30 animais por comparação. Os dados obtidos foram submetidos a análise de variância e comparados pelo teste de Tukey (P<0,05). Foi possível a produção de rações com diferentes EME (8, 20 e 30 kWh/t) e relações ETE:EME, mas com energia específica total próximas. Estas apresentaram mesma densidade aparente, gelatinização do amido e teor de amido resistente. Fornecidas aos animais, tiveram digestibilidade dos nutrientes e da energia semelhantes, resultaram em produção e características das fezes semelhantes e também não alteram a concentração de produtos da fermentação nas fezes. Houve, no entanto, maior complexação de gordura à medida que se aplicou mais EME nos produtos (P<0,05). Cães e gatos apresentaram menor consumo da ração com 30 kWh/t, em comparação às demais (P<0,05). Cães preferiram ainda a ração com 20 em detrimento da com 8 kWh/t (P<0,05), enquanto para gatos estas últimas tiveram consumo...
The efficiency of the extrusion process is directly related to the total energy transferred to the dough feed. Single screw extruders usually implement around 20kWh / ton of specific mechanical energy (SME), but less is known about the implementation of the specific thermal energy (STE) and the implications of the relationship between STE/SME processing of dog food and cats. This study evaluated the effects of the implementation of three relations between STE/SME on the macrostructure of estrusados, gelatinization, loss of nutrients, nutrient digestibility and palatability of food for dogs and cats. For each species, the experiment included a formulation processed in order to obtain three relations STE/SME totaling three diets for species. Nutrient digestibility was studied in 18 dogs or 18 cats, the total collection of feces. The palatability of the diets was compared for the two vessels method, at least 30 animals by comparison. The data were submitted to ANOVA and Tukey's test (P <0.05). Feed production was possible with different SME (8, 20 and 30 kWh / t) and relations STE/SME, but with total specific energy next. These had the same bulk density, gelatinization of starch and resistant starch. Provided to animals showed digestibility and similar energy production and resulted in similar characteristics of feces and does not alter the concentration of the fermentation product in the feces. There was, however, greater complexation fat as applied SME over the products (P <0.05). Dogs and cats had lower consumption of feed with 30 kWh / t, compared others (P <0.05). Dogs further preferred feed 20 over the 8 kWh / t (P <0.05), while for the latter cats had similar consumption. After extrusion was increasing content of some amino acids and an average reduction of 55% of its selenium content (P <0.05). It was concluded that different relations between SME and STE can be applied in the production of food for dogs and cats, with sufficient ...
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Sá, Fabiano Cesar. "Energia mecânica, energia térmica e moagem na extrusão de alimentos para cães e gatos /." Jaboticabal, 2015. http://hdl.handle.net/11449/126533.
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Orientador: Aulus Cavalieri CarciofiBanca: Atushi Sugohara
Banca: Dalton José Carneiro
Banca: Ricardo Souza Vasconcellos
Banca: Luciano Trevisan
Resumo: A eficiência do processo de extrusão está diretamente relacionada à energia total transferida para a massa de ração. Extrusoras de rosca simples usualmente implementam ao redor de 20kWh/ton de energia mecânica específica (EME), mas menos se conhece à respeito da implementação de energia térmica específica (ETE) e das implicações da relação entre ETE:EME no processamento de alimentos para cães e gatos. O presente estudo avaliou os efeitos da implementação de três relações entre ETE:EME sobre a macroestrutura dos estrusados, gelatinização do amido, perda de nutrientes, digestibilidade dos nutrientes e palatabilidade de alimentos para cães e gatos. Para cada espécie, o experimento incluiu uma formulação processada de modo a se obter 3 relações ETE:EME, totalizando 3 dietas por espécie. A digestibilidade dos nutrientes foi estudada com 18 cães ou 18 gatos, pelo método de coleta total de fezes. A palatabilidade das dietas foi comparada pelo método de duas vasilhas, com no mínimo 30 animais por comparação. Os dados obtidos foram submetidos a análise de variância e comparados pelo teste de Tukey (P<0,05). Foi possível a produção de rações com diferentes EME (8, 20 e 30 kWh/t) e relações ETE:EME, mas com energia específica total próximas. Estas apresentaram mesma densidade aparente, gelatinização do amido e teor de amido resistente. Fornecidas aos animais, tiveram digestibilidade dos nutrientes e da energia semelhantes, resultaram em produção e características das fezes semelhantes e também não alteram a concentração de produtos da fermentação nas fezes. Houve, no entanto, maior complexação de gordura à medida que se aplicou mais EME nos produtos (P<0,05). Cães e gatos apresentaram menor consumo da ração com 30 kWh/t, em comparação às demais (P<0,05). Cães preferiram ainda a ração com 20 em detrimento da com 8 kWh/t (P<0,05), enquanto para gatos estas últimas tiveram consumo...
Abstract: The efficiency of the extrusion process is directly related to the total energy transferred to the dough feed. Single screw extruders usually implement around 20kWh / ton of specific mechanical energy (SME), but less is known about the implementation of the specific thermal energy (STE) and the implications of the relationship between STE/SME processing of dog food and cats. This study evaluated the effects of the implementation of three relations between STE/SME on the macrostructure of estrusados, gelatinization, loss of nutrients, nutrient digestibility and palatability of food for dogs and cats. For each species, the experiment included a formulation processed in order to obtain three relations STE/SME totaling three diets for species. Nutrient digestibility was studied in 18 dogs or 18 cats, the total collection of feces. The palatability of the diets was compared for the two vessels method, at least 30 animals by comparison. The data were submitted to ANOVA and Tukey's test (P <0.05). Feed production was possible with different SME (8, 20 and 30 kWh / t) and relations STE/SME, but with total specific energy next. These had the same bulk density, gelatinization of starch and resistant starch. Provided to animals showed digestibility and similar energy production and resulted in similar characteristics of feces and does not alter the concentration of the fermentation product in the feces. There was, however, greater complexation fat as applied SME over the products (P <0.05). Dogs and cats had lower consumption of feed with 30 kWh / t, compared others (P <0.05). Dogs further preferred feed 20 over the 8 kWh / t (P <0.05), while for the latter cats had similar consumption. After extrusion was increasing content of some amino acids and an average reduction of 55% of its selenium content (P <0.05). It was concluded that different relations between SME and STE can be applied in the production of food for dogs and cats, with sufficient ...
Doutor
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Chapple, Charles E. "Finding a needle in haystack: the Eukaryotic selenoproteome." Doctoral thesis, Universitat Pompeu Fabra, 2009. http://hdl.handle.net/10803/7184.
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Les selenoproteïnes constitueixen una família diversa de proteïnes, caracteritzada per la presència del Seleni (Se), en forma de l'amino àcid atípic, la selenocisteïna (Sec). La selenocisteïna, coneguda com l'amino àcid 21, és similar a la cisteïna (Cys) amb un àtom de seleni en lloc de sofre (S). Les selenoproteïnes són els responsables majoritaris dels efectes biològics del seleni i s'ha observat que poden estar implicades en la infertilitat masculina, el càncer, algunes malalties coronàries,l'activació de virus latents i l'envelliment. La selenocisteïna es codifica pel codó UGA, normalment codó de parada (STOP). Per a la recodificació correcta del UGA són necessaris diversos factors. A la part 3' de la regió no traduïda (UTR) dels transcrits dels gens de selenoproteïnes en organismes eucariotes s'hi troba una estructura de "stem-loop" anomenada SECIS. La proteïna SBP2 interactua amb el SECIS, així com amb el ribosoma, i forma un complex amb el factor d'elongació EFsec i el tRNA de la selenocisteïna, el tRNASec. Donat que el codó TGA normalment significa fi de la traducció, les formes tradicionals de cerca de gens no el reconeixen com a codó codificant. Per aquesta raó ha estat necessari desenvolupar una metodologia específica per a la predicció de gens de selenoproteïnes. En els últims anys, hem contribuït a la descripció del selenoproteoma eucariota amb el descobriment de noves famílies (Castellano et al., 2005), amb l'elaboració de nous mètodes (Taskov et al., 2005; Chapple et al., 2009) i l'anotació de diferents genomes (Jaillon et al., 2004; Drosophila 12 genomes Consortium, 2007; Bovine Genome Sequencing and Analysis Consortium, 2009). Finalment, hem identificat el primer animal que no té selenoproteïnes (Drosophila 12 genomes Consortium, 2007; Chapple and Guigó, 2008), un descobriment soprenent donat que, fins el moment, es creia que les selenoproteïnes eren essencials per la vida animal.Selenoproteins are a diverse family of proteins containing the trace element Selenium (Se)in the form of the non-canonical amino acid selenocysteine (Sec). Selenocysteine, the 21st amino acid, is similar to cysteine (Cys)but with Se replacing Sulphur. In many cases the homologous gene of a known selenoprotein is present with cysteine in the place of Sec in a different genome. Selenoproteins are believed to be the effectors of the biological functions of Selenium and have been implicated in male infertility, cancer and heart diseases, viral expression and ageing. Selenocysteine is coded by the opal STOP codon (TGA). A number of factors combine to achieve the co-translational recoding of TGA to Sec. The 3' Untranslated regions (UTRs) of eukaryotic selenoprotein transcripts contain a stem-loop structure called a Sec Insertion Sequence (SECIS) element. This is recognised by the Secis Binding Protein 2 (SBP2), which binds to both the SECIS element and the ribosome. SBP2, in turn, recruits the Sec-specific Elongation Factor EFsec, and the selenocysteine transfer RNA, tRNASec. The dual meaning of the TGA codon means that selenoprotein genes are often mispredicted by the standard annotation pipelines. The correct prediction of these genes, therefore, requires the development of specific methods. In the past few years we have contributed significally to the description of the eukaryotic selenoproteome2 with the discovery of novel families (Castellano et al., 2005), the elaboration of novel methods (Taskov et al., 2005; Chapple et al., 2009) and the annotation of different genomes (Jaillon et al., 2004; Drosophila 12 genomes Consortium, 2007; Bovine Genome Sequencing and Analysis Consortium, 2009). Finally, and perhaps most importantly, we have identified the first animal to lack selenoprotein genes (Drosophila 12 genomes Consortium, 2007; Chapple and Guigó, 2008). This last finding is particularly surprising because it had previously been believed that selenoproteins were essential for animal life.
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Berkaoui, M'hamed. "Réactivité énaminique de β-aminothiophènes vis-à-vis de divers électrophiles. Accès à des hétérocycles thiophéniques azotés." Rouen, 1998. http://www.theses.fr/1998ROUES015.
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Le fort caractère énaminique des 3-aminothiophènes est responsable de la grande réactivité de la position 2 de l'hétérocycle vis-à-vis des réactifs électrophiles et des acides. L'action d'un aldéhyde en présence de sélénophénol, comme réducteur, et de traces acides, ouvre une voie d'accès aux 2-alkyl 3-aminothiophènes et à leurs dérivés acétamides et carbamates. Le mécanisme de cette réaction de C-alkylation suppose la formation d'un carbocation pseudo-benzylique intermédiaire mis en évidence par capture avec le thiophénol ou le pyrrole. En absence de réducteur, on observe une double alkylation aboutissant aux 2,2'-alkylidènebis(3-thiophénamines) et aux 2,2'-alkylidènebis(3-thiényl)acétamides et carbamates en partant de l'acétamide ou d'un carbamate correspondant. La formation de dithiénopyridines à partir des 2,2'-alkylidènebis(3-thiophènamines) illustre la seconde propriété de ces composés, qui découle de la C-protonation, et que nous appelons transamination acido-catalysée. Elle permet d'expliquer la formation de dithiéno[3,2-b:2',3'-e]pyridines. Nous proposons aussi un mécanisme faisant intervenir préalablement une étape d'oxydation. Lorsque l'aldéhyde utilisé est substitué en α , on observe la formation d'une double liaison plus rapide que la réaction du carbocation avec le substrat. Elle conduit aux composés α-vinyliques non fonctionnalisés. Par le même processus, les composés β-(3-amino 2-thiényl)vinylcétones, esters et nitriles sont obtenus à partir des acétals fonctionnalisés correspondants. Ce résultat permet d'établir le mécanisme de formation des thiéno[3,2-b]pyridines fonctionnalisées en position 6 à partir du 3-aminothiophène et de deux équivalents d'acétal fonctionnalisé. Nous accédons également, de manière efficace aux 2-allyl 3-aminothiophènes par α-allylation directe ou par réarrangement de dérivés N-allylés.
Book chapters on the topic "Amido selenide"
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Kirsch, G., E. Perspicace, and S. Hesse. "Synthesis and Transformations of 2- and 3-hydroxy-Selenophenes and 2- and 3-Amino-Selenophenes." In Selenium and Tellurium Chemistry, 239–50. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-20699-3_10.
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Mercier, Y., D. Batonon-Alavo, and P. A. Geraert. "Chapter 8: Selenium and pork meat quality: muscle redox status, selenium, sulphur amino acids and beyond." In Selenium in pig nutrition and health, 235–60. The Netherlands: Wageningen Academic Publishers, 2021. http://dx.doi.org/10.3920/978-90-8686-912-1_8.
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Sato, R. "From Diphenyl Selenide with Potassium Amide." In Six-Membered Hetarenes with Two Identical Heteroatoms, 1. Georg Thieme Verlag KG, 2004. http://dx.doi.org/10.1055/sos-sd-016-00169.
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García Ruano, J. L., M. B. Cid, A. M. Martín-Castro, and J. Alemán. "Reaction with Compounds Containing an Amino Group." In Sulfur, Selenium, and Tellurium, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-039-00416.
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Comasseto, J. V., and A. S. Guarezemini. "Reaction of Indium(III) -Butyl(trimethylsilyl)amide with Alkanethiols." In Sulfur, Selenium, and Tellurium, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-039-00497.
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García-Ruano, J. L., M. B. Cid, A. M. Martín-Castro, and J. Alemán. "Amination of Sulfoxides with Compounds Containing an Amino Group." In Sulfur, Selenium, and Tellurium, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-039-01003.
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Comasseto, J. V., and A. S. Guarezemini. "Reaction of Alkaneselenols or Sodium Alkaneselenolates with Amino- or Haloarsines." In Sulfur, Selenium, and Tellurium, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-039-01221.
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Braverman, S., M. Cherkinsky, and S. Levinger. "Chiral Alkanesulfinamides Using an Amino Alcohol and Thionyl Chloride via Alkanesulfinate Esters." In Sulfur, Selenium, and Tellurium, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-039-00357.
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Kidd, M. T., and P. F. Surai. "Nutritional strategies to boost immune response in poultry." In Optimising poultry flock health, 149–92. Burleigh Dodds Science Publishing, 2022. http://dx.doi.org/10.19103/as.2022.0104.08.
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In this chapter nutritional modulation of immune function, with specific focus on research work from the year 2000 to present, is outlined with respect to immune responsiveness and disease resistance. In order to assess immune enhancement, suppression, and balance, independent sections for vitamins (i.e., carotenoids and vitamin E), minerals (i.e., selenium and zinc), and amino acids (i.e., arginine and threonine) are presented. Further, consideration of other nutrients is given (e.g., vitamin D, manganese, and copper). In addition to nutrients, sections in this chapter also are concerned with the ingredients on immune modulation (i.e., fats, oils, wheat, rye, insect meal, algae meal, and alternatively processed oilseeds). A section on in ovo manipulation of embryo and subsequent chick immunity is presented. Studies assessing few immune parameters versus those assessing overall immune balance in the presence of challenges are discussed.
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Taber, Douglass F. "Best Synthetic Methods: Functional Group Transformations." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0003.
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Vinyl glycine 2 is a useful precursor to a variety of amino acids. Timothy E. Long of the University of Georgia found (Tetrahedron Lett. 2009, 50, 5067) that the o-nitrophenyl sulfoxide 1 eliminated smoothly in refluxing toluene. Alicia Boto and Rosendo Hernández of IPNA La Laguna observed (Tetrahedron Lett. 2009, 50, 3974) that a related selenoxide elimination proceeded to give the single regioisomer 4. Avelino Corma of the Universidad Politécnica de Valencia developed ( Chemical Commun. 2009, 4947) a gold catalyst for the selective hydroboration of alkynes over alkenes. Eiji Shirakawa and Tamio Hayashi of Kyoto University devised (Chemical Commun. 2009, 5088) a Ru catalyst for the conversion of an alkenyl triflate such as 8 to the corresponding bromide. Tristan H. Lambert of Columbia University found (J. Am. Chem. Soc. 2009, 131, 13930) that the dichloride 11 smoothly converted a variety of alcohols into the corresponding chlorides. Crown ethers have been used to promote SN2 reactivity by solubilizing the metal cation. Sungyul Lee of Kyunghee University, Dae Yoon Chi of Sogang University, and Choong Eui Song of Sungkyunkwan University demonstrated (Angew. Chem. Int. Ed. 2009, 48, 7683) that the inexpensive polyethylene glycols were also effective. Mugio Nishizawa of Tokushima Bunri University devised (Synlett 2009, 1175) conditions for the rapid regioselective hydration of hydroxy alkynes such as 15. Jaume Vilarrasa of the Universitat de Barcelona developed (Organic Lett. 2009, 11, 4414) a mild alternative protocol for the Nef reaction, converting a nitroalkane such as 17 into the corresponding ketone under neutral conditions. Clément Mazet of the University of Geneva optimized (Tetrahedron Lett. 2009, 50, 4141) the Ir-catalyzed conversion of an allylic alcohol 19 into the saturated aldehyde. Jonathan M. J. Williams of the University of Bath established (Angew. Chem. Int. Ed. 2009, 48, 7375) that under Ir-catalyzed “borrowing hydrogen” conditions, alkyl amines could donate alkyl groups to anilines such as 21. Danfeng Huang and Yulai Hu of Northwest Normal University devised (Organic Lett. 2009, 11, 4474) a simple protocol for conversion of an acid 23 to the Weinreb amide 24. of the Universitat
Conference papers on the topic "Amido selenide"
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Erkan, Mehmet Eray, Chun-Young Lee, Shenbin D. Wu, Jong-Youb Lim, Donggun Lim, Kyungkon Kim, and Michael H. C. Jin. "CuInSe2 solar cells prepared by using seleno-amide as selenium source." In 2011 37th IEEE Photovoltaic Specialists Conference (PVSC). IEEE, 2011. http://dx.doi.org/10.1109/pvsc.2011.6185967.
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