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1
Christensen, M. K., C. J. Frederickson e G. Danscher. "Retrograde tracing of zinc-containing neurons by selenide ions: a survey of seven selenium compounds." Journal of Histochemistry & Cytochemistry 40, n. 4 (aprile 1992): 575–79. http://dx.doi.org/10.1177/40.4.1313065.
Testo completoAbstract (sommario):
The autometallographic retrograde tracing of zinc-containing neurons by intracerebral injection of sodium selenite (Na2SeO3), introduced by Danscher in 1982, has recently been described in more detail. Intracerebral injections of both sodium selenide (Na2Se) and sodium selenite (Na2SeO3) have been successfully used; however, sodium selenite had a rather toxic effect on the injected tissue. In the present study, we tested seven different selenium compounds to find the most suitable compound for retrograde tracing of zinc-positive pathways. Among the tested compounds, sodium selenide (Na2Se) caused insignificant necrosis within the injection site and was easily transported retrogradely when handled anaerobically. Sodium selenide is therefore recommended as the compound of choice.
2
Cemeli, Eduard, Ricard Marcos e Diana Anderson. "Genotoxic and antigenotoxic properties of selenium compounds in thein vitromicronucleus assay with human whole blood lymphocytes and tk6 lymphoblastoid cells". Scientific World JOURNAL 6 (2006): 1202–10. http://dx.doi.org/10.1100/tsw.2006.204.
Testo completoAbstract (sommario):
Selenium is known to possess both genotoxic and antigenotoxic properties. In the present study, we have evaluated the genotoxicity and antigenotoxicity of three selenium compounds (sodium selenate, sodium selenite and selenous acid) by measuring in vitro micronucleus induction. Assays were conducted in whole blood lymphocytes and in the TK6 lymphoblastoid cell line, with and without co-treatment with potassium dichromate, a known genotoxic compound. In general, the compounds were more active in TK6 cells than they were in blood lymphocytes. Only 1 μM selenous acid increased the frequency of binucleated cells containing micronuclei (BNMN) in blood lymphocytes, while all three selenium compounds increased BNMN in TK6 cells. In addition, combinations of selenous acid and potassium dichromate resulted in lower frequencies of BNMN than potassium dichromate alone in blood lymphocytes, while combinations of sodium selenate and potassium dichromate produced lower frequencies of BNMN than potassium dichromate alone in TK6 cells. The concentrations of selenium compounds that were used, in combination with the medium components and the biological physiology of the whole blood lymphocytes and TK6 cells, could have affected the redox potential of the compounds, switching the chemicals from a pro-oxidant to antioxidant status and vice-versa. The lower activities of the compounds in blood lymphocytes may be due to the protective effects of blood components. The results indicate that the genotoxic and antigenotoxic properties of selenium compounds are highly dependent upon the conditions under which they are evaluated.
3
Francisco Sánchez-Viesca e Reina Gómez. "The mechanism of Mecke’s test for opioids". World Journal of Chemical and Pharmaceutical Sciences 2, n. 1 (30 gennaio 2023): 023–27. http://dx.doi.org/10.53346/wjcps.2023.2.1.0014.
Testo completoAbstract (sommario):
Mecke colour test is an official assay for opioids, either for opium or for purified compounds. It employs a solution of selenious acid in sulphuric acid. However, organoselenium chemistry was misunderstood for many years. The reaction mechanism involving selenium (IV) compounds was explained by way of electron back donation, which is a theoretical contravention. In this communication we provide the reactions that take place during this test. Each step is fully commented and the electron flow is given. The reaction proceeds by way of an enol selenite. Acidolysis gives rise to a reduced selenium (II) intermediate and an activated ketone at C-2, that is, a redox reaction with polarity inversion. Addition of selenious acid and further electron shifts affords morphine ortho-quinone and elemental selenium.
4
GLOTOVA, I. A., N. A. GALOCHKINA, V. F. SELEMENEV, O. V. PEREGONCHAYA e S. A. SOKOLOVA. "IR-SPECTROSCOPIC STUDY OF IMMOBILIZATION OF SELENIUM COMPOUNDS ON BIOMODIFIED COLLAGEN". Periódico Tchê Química 16, n. 33 (20 marzo 2019): 159–68. http://dx.doi.org/10.52571/ptq.v16.n33.2019.174_periodico33_pgs_159_168.pdf.
Testo completoAbstract (sommario):
The aim of the work was to research the spectral characteristics of collagen substances bioengineered by using complex collagenolytic proteases preparation obtained before and after the immobilization of selenium compounds in acidic and alkaline media and to comparate the degree of interaction of selenium preparations with collagen matrix upon immobilization and its influence on the conformation of protein molecules. The results of the immobilization of selenium preparations on biomodified collagen by the IR spectroscopy method are presented, analyzed, and discussed. Biomodified collagen was obtained from beef trimming waste (veins and tendons) by sequential peroxide-alkaline and enzymatic hydrolysis with the food collagenase preparation. The following sources of selenium were used as compounds with bioprotective properties for subsequent immobilization on biomodified collagen proteins: 4,4-di[3(5-methyldiprazolil)]selenide (DMDPS) with the content of 0,657g DMDMS in 100 cm3 and sodium selenite. Spectrograms are carried out for products of biomodification of collagen before sorption of compounds of selenium, (at the rate of 1.2 g-6 of selenium on 1 g of collagen) in acid (рН =5) and alkaline (рН =10) environments at a research of influence of compounds of selenium on IR spectrums of products of biomodification of collagen. It was established, that the immobilization takes place by a chemical reaction of selenium preparations with functional groups of the side chains of protein molecules, and its degree varies in the range Na2SeO3 (pH=5) > 4,4-di[3(5-methyldiprazolil)]selenide (DMDPS) > Na2SeO3 (pH=10). It is shown that under the interaction of selenium products with collagen, there is no change in the conformations of its molecules occurred.
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Eom, Taejun, e Anzar Khan. "Selenium-Epoxy ‘Click’ Reaction and Se-Alkylation—Efficient Access to Organo-Selenium and Selenonium Compounds". Chemistry 2, n. 4 (5 ottobre 2020): 827–36. http://dx.doi.org/10.3390/chemistry2040054.
Testo completoAbstract (sommario):
This work establishes the ‘click’ nature of the base-catalyzed oxirane ring opening reaction by the selenolate nucleophile. The ‘click’-generated ß-hydroxy selenide can be alkylated to afford cationic selenium species. Hemolytic studies suggest that selenonium cations do not lyse red blood cells even at high concentrations. Overall, these results indicate the future applicability of the developed organo-selenium chemistry in the preparation of a new class of cationic materials based on the seleno-ether motif.
6
Nevitov, Mikhail, Aleksandr Ostapchuk, Pavel Poluboyarinov, Aleksey Gamayunov, Polina Anipchenko, Anatoly Stekolnikov, Kirill Plemyashov et al. "PSVI-33 Queen bees’ artificial breeding using selenium compounds". Journal of Animal Science 97, Supplement_3 (dicembre 2019): 205–6. http://dx.doi.org/10.1093/jas/skz258.423.
Testo completoAbstract (sommario):
Abstract The aim of the study was to research the effect of selenium-containing drugs on the efficiency of artificial hatching, using them in the composition of feeding of starter-families. The experiment was conducted in a private apiary located in the Penza region, Russia (30 bee colonies). The predominant honey plants - melilot, rose bay. The average productivity -65–70 kg of marketable honey.In the maternal family, 1.5-day-old larvae were taken, transferred to artificial pans and placed for a day in the family-starters, and then - in the queen-rearing colony. Families-starters once received a sugar syrup with selenium-containing drugs. Sugar syrup(S) was prepared in a 1: 1 ratio, selenium drugs were added to it. The introduction of selenopyran as part of top-dressing to the starter-family at a dose of 0.2 mg of selenium per 1 kg of bees causes an increase in selenium content in the body of bees by 138%, while the administration of sodium selenite and selenocystin does not lead to significant changes in the selenium status of insects under the same conditions.Sodium selenite, introduced as part of top-dressing to the family-starter up to 0.2 mg selenium per 1 kg of bee mass, increases the selenium content in the body of the queens that were in the 1st day of development in this family by 225%, while selenopyran with this method administration causes an increase in selenium level in the body of the uterus by 121%, and selenocystin - by 73%, compared with the control.The use of selenocystine and sodium selenite as part of feeding to starter families contributes to better preservation of the larvae in the development process in queen-rearing colony, compared with the control and provides a higher yield of queens (respectively, 214% and 157% higher).
7
Garayev, A. M., e A. B. Rzayeva. "SOLVOTHERMAL SYNTHESIS OF TRIPLE NANO COMPOUNDS BISBSE3 IN A LIQUID PHASE". EurasianUnionScientists 5, n. 7(76) (20 agosto 2020): 68–72. http://dx.doi.org/10.31618/esu.2413-9335.2020.5.76.931.
Testo completoAbstract (sommario):
Ternary compounds of bismuth antimony selenide have been synthesized under solvothermal conditions in ethylene glycol medium at the temperature of 453-463 K during 15 hours from bismuth (III) oxide, antimony (III) oxide, elemental selenium (amorph) and hydrazine monohydrate. At a temperature of 453-463 K, after a 15-hour synthesis, a flocculent precipitate is obtained. The thermographic, differential thermal (DTA), X-ray (XRD), chemical, and morphological analyses of the compound were performed and it was found that the crystals of the compound are presented in the form of nano and micro-shelves. The results showed that the composition of selenium compounds of antimony bismuth corresponds to the BiSbSe3 formulas
8
Swearingen, J. W., D. E. Fuentes, M. A. Araya, M. F. Plishker, C. P. Saavedra, T. G. Chasteen e C. C. Vásquez. "Expression of the ubiE Gene of Geobacillus stearothermophilus V in Escherichia coli K-12 Mediates the Evolution of Selenium Compounds into the Headspace of Selenite- and Selenate-Amended Cultures". Applied and Environmental Microbiology 72, n. 1 (gennaio 2006): 963–67. http://dx.doi.org/10.1128/aem.72.1.963-967.2006.
Testo completoAbstract (sommario):
ABSTRACT The ubiE gene of Geobacillus stearothermophilus V, with its own promoter, was cloned and introduced into Escherichia coli. The cloned gene complemented the ubiE gene deficiency of E. coli AN70. In addition, the expression of this gene in E. coli JM109 resulted in the evolution of volatile selenium compounds when these cells were grown in selenite- or selenate-amended media. These compounds were dimethyl selenide and dimethyl diselenide.
9
Mal’tseva, Valentina N., Michael V. Goltyaev, Egor A. Turovsky e Elena G. Varlamova. "Immunomodulatory and Anti-Inflammatory Properties of Selenium-Containing Agents: Their Role in the Regulation of Defense Mechanisms against COVID-19". International Journal of Molecular Sciences 23, n. 4 (21 febbraio 2022): 2360. http://dx.doi.org/10.3390/ijms23042360.
Testo completoAbstract (sommario):
The review presents the latest data on the role of selenium-containing agents in the regulation of diseases of the immune system. We mainly considered the contributions of selenium-containing compounds such as sodium selenite, methylseleninic acid, selenomethionine, and methylselenocysteine, as well as selenoproteins and selenium nanoparticles in the regulation of defense mechanisms against various viral infections, including coronavirus infection (COVID-19). A complete description of the available data for each of the above selenium compounds and the mechanisms underlying the regulation of immune processes with the active participation of these selenium agents, as well as their therapeutic and pharmacological potential, is presented. The main purpose of this review is to systematize the available information, supplemented by data obtained in our laboratory, on the important role of selenium compounds in all of these processes. In addition, the presented information makes it possible to understand the key differences in the mechanisms of action of these compounds, depending on their chemical and physical properties, which is important for obtaining a holistic picture and prospects for creating drugs based on them.
10
Bandura, Laura, Justyna Drukala, Agnieszka Wolnicka-Glubisz, Mikael Björnstedt e Wlodzimierz Korohoda. "Differential effects of selenite and selenate on human melanocytes, keratinocytes, and melanoma cells". Biochemistry and Cell Biology 83, n. 2 (1 aprile 2005): 196–211. http://dx.doi.org/10.1139/o04-130.
Testo completoAbstract (sommario):
Among the substances that attracted the attention of oncologists in recent years are selenium-containing compounds, both inorganic and organic. Several epidemiological studies have shown an inverse correlation between selenium intake and cancer incidence. In the experiments reported here, we compared the effects of 2 inorganic selenium- containing salts that differed in the level of selenium oxidation, selenite IV and selenate VI. We tested the effects of these 2 compounds on cell survival and growth, cell cycle processing, cell morphology, cytoskeleton, and lipid peroxidation in 3 human skin cell types: normal keratinocytes, melanocytes, and human melanoma cell line HTB140. The different effects of selenite and selenate on the viability, growth, and morphology of normal cells and tumor cells are reported and provide a base for future research and treatment of some neoplastic diseases. The attention is paid to cell apoptosis induced by selenite and not by selenate, and the effects of tested substances on thioredoxin reductase system are postulated.Key words: selenium, cell viability and growth, apoptosis, lipid oxidation, thioredixin reductase system, human skin cells, human melanoma.
11
Kieliszek, Marek, e Stanisław Błażejak. "Speciation Analysis of Selenium in Candida utilis Yeast Cells Using HPLC-ICP-MS and UHPLC-ESI-Orbitrap MS Techniques". Applied Sciences 8, n. 11 (25 ottobre 2018): 2050. http://dx.doi.org/10.3390/app8112050.
Testo completoAbstract (sommario):
Selenium plays a key role in the proper metabolism of living organisms. The search for new selenium compounds opens up new possibilities for understanding selenometabolome in yeast cells. This study was aimed at the identification of compounds containing selenium in the feed yeasts Candida utilis ATCC 9950. Yeast biomass was kept in aqueous solutions enriched with inorganic selenium (20 mg·L−1) for 24 h. Speciation analysis of the element was performed using the HPLC-ICP-MS and UHPLC-ESI-Orbitrap MS techniques. The obtained selenium value in the yeast was 629 μg·g−1, while the selenomethionine value was 31.57 μg·g−1. The UHPLC-ESI-Orbitrap MS analysis conducted allowed for the identification of six selenium compounds: dehydro-selenomethionine-oxide, selenomethionine, selenomethionine-NH3, a Se-S conjugate of selenoglutathione-cysteine, methylthioselenoglutathione, and 2,3-DHP-selenocysteine-cysteine. In order to explain the structure of selenium compounds, the selected ions were subjected to fragmentation. The selenium compounds obtained with a low mass play a significant role in the metabolism of the compound. However, the bioavailability of such components and their properties have not been fully understood. The number of signals indicating the presence of selenium compounds obtained using the UHPLC-ESI-Orbitrap MS method was characterized by higher sensitivity than when using the HPLC-ICP-MS method. The obtained results will expand upon knowledge about the biotransformation of selenium in eukaryotic yeast cells. Future research should focus on understanding the entire selenium metabolism in cells and on the search for new transformation pathways for this element. This opens up new possibilities for obtaining functional food, rich in easily absorbable selenium sources, and constituting an alternative to dietary supplements based on this compound found primarily in inorganic form.
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Wallenberg, Marita, Eric Olm, Christina Hebert, Mikael Björnstedt e Aristi P. Fernandes. "Selenium compounds are substrates for glutaredoxins: a novel pathway for selenium metabolism and a potential mechanism for selenium-mediated cytotoxicity". Biochemical Journal 429, n. 1 (14 giugno 2010): 85–93. http://dx.doi.org/10.1042/bj20100368.
Testo completoAbstract (sommario):
The Grx (glutaredoxin) proteins are oxidoreductases with a central function in maintaining the redox balance within the cell. In the present study, we have explored the reactions between selenium compounds and the glutaredoxin system. Selenite, GS-Se-SG (selenodiglutathione) and selenocystine were all shown to be substrates of human Grx1, implying a novel role for the glutaredoxins in selenium metabolism. During the past few years, selenium has further evolved as a potential therapeutic agent in cancer treatment, and a leading mechanism of cytotoxicity is the generation of ROS (reactive oxygen species). Both selenite and GS-Se-SG were reduced by Grx1 and Grx2 in a non-stoichiometric manner due to redox cycling with oxygen, which in turn generated ROS. The role of Grx in selenium toxicity was therefore explored. Cells were treated with the selenium compounds in combination with transient overexpression of, or small interfering RNA against, Grx1. The results demonstrated an increased viability of the cells during silencing of Grx1, indicating that Grx1 is contributing to selenium toxicity. This is in contrast with TrxR (thioredoxin reductase), which previously was shown to protect cells from selenium cytotoxicity, verifying a diverse role between Grx and TrxR in selenium-mediated cytotoxicity. Furthermore, selenium treatment led to a marked increase in protein glutathionylation and cysteinylation that potentially can influence the activity and function of several proteins within the cell.
13
Nechvoglod, Olga Vladimirovna, Evgeny N. Selivanov, Vladimir Chumarev e Denis Toloknov. "Thermodynamic Simulation of the Oxidation Processes of Ag2Se by NaNO2". Defect and Diffusion Forum 353 (maggio 2014): 111–15. http://dx.doi.org/10.4028/www.scientific.net/ddf.353.111.
Testo completoAbstract (sommario):
The thermodynamic simulation of the oxidation processes of silver selenide by reagents such as NaNO2, NaNO3 and NaOH during their heat treatment has been conducted. Gibbs energy of silver selenide oxidation reactions has been estimated. It is shown as a reagent–oxidant of silver selenide it is rationally to use a mixture of sodium nitrite and sodium hydroxide. Oxidation of silver selenide during heat treatment together with sodium nitrite and sodium hydroxide is accompanied by the formation of soluble compounds such as Na2SeO3 and Na2SeO4, silver being passed in the metallic state. Separation coefficients characterizing oxidation efficiency and the level of selenium transfer in soluble compounds were estimated. Using the data the separation method of materials containing selenides by means of their sintering with sodium-containing reagents is proposed. The method is based on the transfer of selenium in the water-soluble compounds followed by leaching, precious metals being the elemental state. The products obtained are suitable for the production of selenium and precious metals by traditional technologies.
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Yang, Dan-Yi, Yu-Wei Chen, John M. Gunn e Nelson Belzile. "Selenium and mercury in organisms: Interactions and mechanisms". Environmental Reviews 16, NA (dicembre 2008): 71–92. http://dx.doi.org/10.1139/a08-001.
Testo completoAbstract (sommario):
This paper reviews the growing literature dealing with the antagonistic effect of selenium (Se) compounds on the toxicity of mercury (Hg) compounds in higher animals and organisms present in the aquatic environment. It covers both laboratory and field studies and summarizes the possible mechanisms that explain the protective action of Se compounds on mercuric mercury (Hg2+) and methylmercury (CH3Hg+) toxicity. The review is subdivided according to the molecular form of Hg and the organisms in which the antagonism has been studied. Many authors suggest that the protective effect of selenite on the toxicity of Hg2+in mammals is due mainly to the in vivo formation of mercuric selenide (HgSe), a stable and biologically inert complex. The detection of HgSe has been confirmed in several studies in support of this mechanism. Possible mechanisms that may be involved in the antagonism between Se compounds and CH3Hg+in mammals and aquatic organisms are also presented. The possibility of adding Se compounds to contaminated lakes and reservoirs as a remediation technique to limit the bioaccumulation of Hg2+and CH3Hg+is critically discussed.
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Mechora, Špela, Mateja Germ e Vekoslava Stibilj. "Selenium compounds in selenium-enriched cabbage". Pure and Applied Chemistry 84, n. 2 (10 gennaio 2012): 259–68. http://dx.doi.org/10.1351/pac-con-11-07-19.
Testo completoAbstract (sommario):
For the study, cabbage (Brassica oleracea var. capitata L.) and red cabbage (Brassica oleracea var. capitata L. f. rubra) were treated with Na selenate. Cabbage was foliarly sprayed twice with 20 mg Se(VI) L–1, while red cabbage was fertilized twice with 0.5 mg Se(VI) L–1. Despite the high dose of Se, no toxic effects were observed on cabbage plants. The total Se concentration in cabbage leaves was 4.80 ± 0.25 μg Se g–1 (DM) and in red cabbage 0.96 ± 0.04 μg Se g–1 (DM). Soluble Se compounds were extracted from parts of cabbage with protease XIV, resulting in 49 % of soluble Se from roots, 59 % from leaves, and 65 % from stems. In red cabbage, the corresponding figures were 28 % of soluble Se in roots, 31 % in stems, and 43 % in leaves. Se species were determined in the enzymatic extracts using ion exchange high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). The main Se species found in all parts of cabbage and red cabbage was selenomethionine (SeMet), which in roots represented 94 and 55 % of the soluble Se content in cabbage and red cabbage, respectively. In stems and leaves of cabbage, SeMet represented only 23 % of the soluble Se content. In stems of red cabbage SeMet represented 80 % and in leaves 41 % of the soluble Se content. We observed that traces of Se(VI) were present in upper parts of both plants.
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Luxem, Katja E., Bas Vriens, Renata Behra e Lenny H. E. Winkel. "Studying selenium and sulfur volatilisation by marine algae Emiliania huxleyi and Thalassiosira oceanica in culture". Environmental Chemistry 14, n. 4 (2017): 199. http://dx.doi.org/10.1071/en16184.
Testo completoAbstract (sommario):
Environmental contextVolatile selenium compounds from the oceans may ultimately be an important selenium source for agricultural soils. It has been hypothesised that marine algae are responsible for volatile selenium emissions, but in laboratory experiments, we observed minimal volatile selenium production by two marine algae known to produce large amounts of volatile sulfur. Instead, we found hints that bacterial processes may be important in the production of volatile selenium in the oceans. AbstractVolatile methylated selenium compounds, especially dimethylselenide, are thought to comprise the majority of marine selenium emissions. Despite their potential importance for the global redistribution of this trace element, which is essential for human health, little is known about the algal production of volatile organic selenium compounds. Previous studies have found correlations between dissolved dimethylselenide concentrations, dimethylsulfide concentrations (the sulfur analogue of dimethylselenide) and proxies for algal activity, most notably during a bloom of the coccolithophorid Emiliania huxleyi. In culturing studies, we investigated the ability of three globally important marine algal species, E. huxleyi, Phaeocystis globosa and the diatom Thalassiosira oceanica, to produce dimethylselenide. Despite substantial uptake of selenium and the production of volatile sulfur, E. huxleyi and T. oceanica produced negligible volatile selenium (<2nM). P. globosa produced low amounts of volatile selenium (~8nM), but grew poorly in our laboratory. However, cultures of marine bacteria and mixed bacterial–algal cultures showed that substantial amounts of volatile selenium can be produced in the presence of marine bacteria. In addition, a culture of marine bacteria alone produced ~50nM volatile selenium, far more than axenic cultures of E. huxleyi when exposed to equivalent selenite concentrations. Our results hint that marine algae may be of minor importance in the direct production of volatile selenium in the oceans, and suggest that the production of these compounds in the marine biosphere may instead be controlled by bacterial activity.
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Kieliszek, Marek. "Selenium–Fascinating Microelement, Properties and Sources in Food". Molecules 24, n. 7 (3 aprile 2019): 1298. http://dx.doi.org/10.3390/molecules24071298.
Testo completoAbstract (sommario):
Selenium is a micronutrient that is essential for the proper functioning of all organisms. Studies on the functions of selenium are rapidly developing. This element is a cofactor of many enzymes, for example, glutathione peroxidase or thioredoxin reductase. Insufficient supplementation of this element results in the increased risk of developing many chronic degenerative diseases. Selenium is important for the protection against oxidative stress, demonstrating the highest activity as a free radical scavenger and anti-cancer agent. In food, it is present in organic forms, as exemplified by selenomethionine and selenocysteine. In dietary supplementation, the inorganic forms of selenium (selenite and selenate) are used. Organic compounds are more easily absorbed by human organisms in comparison with inorganic compounds. Currently, selenium is considered an essential trace element of fundamental importance for human health. Extreme selenium deficiencies are widespread among people all over the world. Therefore, it is essential to supplement the deficiency of this micronutrient with selenium-enriched food or yeast cell biomass in the diet.
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Tran, Trang Minh, Dung Tien Pham, Phong Quoc Le e Hiep Minh Dinh. "Study on the selenium absorptive ability of Ophiocordyceps sinensis fungus in liquid cultures". Science and Technology Development Journal 19, n. 4 (31 dicembre 2016): 53–61. http://dx.doi.org/10.32508/stdj.v19i4.705.
Testo completoAbstract (sommario):
Ophiocordyceps sinensis is a medicinal mushroom which is highly valued in traditional and modern medicine. Besides, selenium (Se) is an essential trace element in the human body. Therefore, the study on selenium accumulation ability of O. sinensis fungus to improve its bioactivities as well as selenium bioavailability is extremely imperative. In this research, O. sinensis cultured on liquid medium with sodium selenite (Se+4) or sodium selenate (Se+6) at 0–30 mg/L concentrations, then isolated three selenium-containing compounds including selenium-exopolysaccharide (Se-EPS), selenium-polysaccharide (Se-PS) and selenium-protein (Se-Pr). The results showed that the growth and selenium cumulation of O. sinensis at 25 mg/L Se6+ were the best with the biomass and selenium levels reached 14.52 ± 0.82 g/L and 1644.83 ± 116.45 μg/g, respectively. Of those, the selenium composition in organic compounds was 568.84 ± 12.86 μg/g in Se-EPS, 429.68 ± 22.17μg/g in Se-PS and 443.19 ± 18.48 μg/g in Se-Pr. Moreover, the FT-IR analysis of the aforementioned compounds determined the presence of Se=O and C-O-Se stretching vibration at the featured absorption peaks. Consequently, these results have demonstrated that O. sinensis is capable to transform inorganic Se into organic Se forms during its development process. Finally, this study will create premises and scientific basis for the further study on the Se-enriched substances in O. sinensis mushroom.
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Chomchan, Rattanamanee, Sunisa Siripongvutikorn, Panupong Puttarak e Rungtip Rattanapon. "Influence of selenium bio-fortification on nutritional compositions, bioactive compounds content and anti-oxidative properties of young ricegrass (Oryza sativa L.)". Functional Foods in Health and Disease 7, n. 3 (31 marzo 2017): 195. http://dx.doi.org/10.31989/ffhd.v7i3.321.
Testo completoAbstract (sommario):
Background: Young ricegrass (Oryza sativa L.) can be introduced as one of functional food product since sprouts have been much interested in this era due to their high nutritive values. Bio-fortification of selenium is one strategy to enhance plant bioactivity. However, the level of selenium used is varied among species of plants, hence, the proper level needs to be explored.Objective: To investigate the influence of selenium bio-fortification on nutritional compositions, bioactive compounds content and anti-oxidative properties of young ricegrass.Methods: Sodium selenite ranging 0, 10, 20, 30 and 40 mg Se/L has been hydroponically bio-fortified into ricegrass then grown for 8 d and investigated the changes of growth characteristics, selenium content, accumulation of bioactive compounds and anti-oxidative properties.Results: Results revealed that selenium bio-fortified exogenously increased the accumulation of selenium in ricegrass by 529% at 40 mg Se/L treatment without negatively changes in leaves biomass at the day of harvesting. However, root part weight slightly decreased when increased selenium level. Selenium at concentration of 10 and 20 mg Se/L can stimulate the production of phenolic compounds and antioxidant activities in young ricegrass as measured by DPPH, ABTS, FRAP and chelating assay. Conversely, higher level of selenium fortification reduced the accumulation of phenolics in ricegrass may due to pro-oxidant expression.Conclusion: Selenium bio-fortification can be used as a useful technique to improve quality of ricegrass plantation. 10 mg Se/L treatment was an ideal to trigger the synthesis of phenolics which exhibited high antioxidant activities. While, 40 mg Se/L treatment was ultimate for the production of Se plant foods.Keywords: Antioxidant activities; Bio-fortification; Ricegrass; Selenium
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Azizi, Zohreh, e Arash Babakhanian. "Fabricating a new electrochemically modified pencil graphite electrode based on acetophenone (2,4-dinitrophenyl)hydrazone for determining selenium in food and water samples". Analytical Methods 10, n. 43 (2018): 5205–13. http://dx.doi.org/10.1039/c8ay01959b.
Testo completo
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Xu, Mengmeng, Song Zhu, Lingling Wang, Zhiyi Wei, Liting Zhao, Guiyang Shi e Zhongyang Ding. "Influence of Selenium Biofortification on the Growth and Bioactive Metabolites of Ganoderma lucidum". Foods 10, n. 8 (12 agosto 2021): 1860. http://dx.doi.org/10.3390/foods10081860.
Testo completoAbstract (sommario):
Selenium biofortification of edible and medicinal mushrooms is an effective way to produce selenium-enriched food supplements. Ganoderma lucidum is the typical one with excellent biological activity. This study investigated G. lucidum growth and bioactive metabolites alterations during liquid culture with different concentrations of selenite. Low selenium levels did not affect growth and mycelia morphology, whereas high selenium levels negatively influenced growth, dramatically decreased biomass, caused nucleic acid and protein leakage, damaged cell walls and membranes, and resulted in indicators such as degraded cells, a red color, and an unpleasant odor. Through headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) analysis, ten volatile Se compounds were identified in G. lucidum with 200 ppm selenite, which led to an odor change, whereas only three with 50 ppm selenite. SeMet was the major selenoamino acid in the 50 ppm selenite group by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS), but more MeSeCys was produced with 200 ppm selenite. Polysaccharide yields were promoted and inhibited with 50 and 200 ppm selenite, respectively. These results provide comprehensive insights into the effects of selenite on G. lucidum in liquid culture and are beneficial for functional selenium-enriched mushroom production and improving nutritive values.
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Məmməd oğlu Qarayev, Əhməd, e Aliyə Bayram Rzayeva. "Studying of obtaining conditions of bismuth selenide in the aquatic medium". SCIENTIFIC RESEARCH 08, n. 4 (27 aprile 2022): 189–93. http://dx.doi.org/10.36719/2789-6919/08/189-193.
Testo completoAbstract (sommario):
Məqalədə bismut oksidin elementar selenlə qarşılıqlı təsirindən bismut(III) selenidə su mühitində trasformasiya şəraiti öyrənilməsi verilmişdir. Birləşmənin əmələ gəlməsinin temperaturdan, mühitin pH-dan, reduksiyaedicinin miqdarından asılılığı araşdırılmış və prosesin reaksiya tənliyi tərtib edilmişdir. Alınan maddənin fiziki kimyəvi xassələri TQ, DTA, RFA, və kimyəvi analiz metodları ilə müəyyən edilmişdir. Termoqravimetrik analizlə nümunədə Bi:Se nisbəti 90.65:49.98 təşkil etmişdir. Differensial termiki analizlə nümunənin ərimə temperaturunun 7050C olduğu təyin edilmişdir. Rentgen quruluş analizi nümunənin fərdiliyini təsdiq etmişdir. Belə ki, difraktoqramda alınan piklərin intensivliyi və bucaq qiymətləri etalon qiymətlərinə uyğun gəlmişdir. Qeyd olunlara əsasən nümunənin tərkibinin Bi2Se3 formuluna uyğun gəldiyi dəqiqləşdirilmişdir. Açar sözlər: çökdürmə, su mühiti, bismut oksid, rentgen analiz, kimyəvi analiz, bismut(III) selenid Ahmed Memmed Garayev Aliya Bayram Rzayeva Studying of obtaining conditions of bismuth selenide in the aquatic medium Abstract The article presents the study of the transformation conditions of bismuth (III) selenium in the aquatic environment from the interaction of bismuth oxide with elemental selenium. The dependence of the formation of the compound on temperature, pH of the medium, the amount of reducing agent was studied and the reaction equation of the process was compiled. The physical and chemical properties of the obtained compounds were determined by TQ, DTA, RFA, and chemical analysis methods. By thermogravimetric analysis, the Bi: Se ratio in the sample was 90.65: 49.98. The melting temperature of the sample was determined at 705 0C by the differential thermal analysis. X-ray structure analysis confirmed the individuality of the sample. Thus, the intensity and angle values of the peaks obtained in the diffractogram corresponded to the reference values. Based on the above, it was clarified that the composition of the sample corresponds to the formula Bi2Se3. Key words: sedimentation, aquatic medium, bismuth oxide, x-ray analysis, chemical analysis bismuth(III) selenide.
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Shi, Chen-Yang, Yin-Chin Hew e Choon-Nam Ong. "Inhibition of aflatoxin B1-induced cell injury by selenium: an in vitro study". Human & Experimental Toxicology 14, n. 1 (gennaio 1995): 55–60. http://dx.doi.org/10.1177/096032719501400111.
Testo completoAbstract (sommario):
Dietary selenium is an essential trace element in human nutrition. Selenium has been shown in animal studies to inhibit aflatoxin hepatocarcinogenesis. However, the cellu lar mechanism responsible for the inhibition has not been thoroughly studied. This study examines the effect of two selenium compounds, namely, sodium selenite and selenium- enriched yeast extract (SeY), on the cytotoxicity, DNA- binding and mutagenicity of aflatoxin B1 (AFB1) in cul tured Chinese hamster ovary (CHO) cells. CHO cells, after treatment with 2 μg ml-1 selenite or 80 μg ml-1 SeY, exhibit ed increased resistance to AFB1-induced cell killing. At a concentration of 50 μg ml-1 AFB1, cell survival, measured by the clonogenicity assay, was increased by 21- and 10- fold in selenite- and SeY-treated cells, respectively. However, selenium treatment did not appear to affect AFB1-DNA binding. Similarly, no effect was observed on AFB1 mutagenicity, as determined by the hypoxanthine- guanine phosphoribosyl transferase (HPRT) gene mutation assay. The results showed that selenium could effectively protect cells from AFB1 cytotoxicity in cultured cells but had no effect on AFB1-DNA adduct formation or mutagen esis. It is suggested that there are multiple pathways of AFB1 toxicity and that selenium can modulate AFB1- induced cell killing independent of its genotoxicity.
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Pyrzynska, Krystyna. "Speciation of Selenium Compounds." Analytical Sciences 14, n. 3 (1998): 479–83. http://dx.doi.org/10.2116/analsci.14.479.
Testo completo
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Weiss, J. F., V. Srinivasan, K. S. Kumar, M. L. Patchen e M. R. Landauer. "Radioprotection by selenium compounds". Biological Trace Element Research 33, n. 1-3 (aprile 1992): 164–65. http://dx.doi.org/10.1007/bf02784015.
Testo completo
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Zawadzka, Anna M., Ronald L. Crawford e Andrzej J. Paszczynski. "Pyridine-2,6-Bis(Thiocarboxylic Acid) Produced by Pseudomonas stutzeri KC Reduces and Precipitates Selenium and Tellurium Oxyanions". Applied and Environmental Microbiology 72, n. 5 (maggio 2006): 3119–29. http://dx.doi.org/10.1128/aem.72.5.3119-3129.2006.
Testo completoAbstract (sommario):
ABSTRACT The siderophore of Pseudomonas stutzeri KC, pyridine-2,6-bis(thiocarboxylic acid) (pdtc), is shown to detoxify selenium and tellurium oxyanions in bacterial cultures. A mechanism for pdtc's detoxification of tellurite and selenite is proposed. The mechanism is based upon determination using mass spectrometry and energy-dispersive X-ray spectrometry of the chemical structures of compounds formed during initial reactions of tellurite and selenite with pdtc. Selenite and tellurite are reduced by pdtc or its hydrolysis product H2S, forming zero-valent pdtc selenides and pdtc tellurides that precipitate from solution. These insoluble compounds then hydrolyze, releasing nanometer-sized particles of elemental selenium or tellurium. Electron microscopy studies showed both extracellular precipitation and internal deposition of these metalloids by bacterial cells. The precipitates formed with synthetic pdtc were similar to those formed in pdtc-producing cultures of P. stutzeri KC. Culture filtrates of P. stutzeri KC containing pdtc were also active in removing selenite and precipitating elemental selenium and tellurium. The pdtc-producing wild-type strain KC conferred higher tolerance against selenite and tellurite toxicity than a pdtc-negative mutant strain, CTN1. These observations support the hypothesis that pdtc not only functions as a siderophore but also is involved in an initial line of defense against toxicity from various metals and metalloids.
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Kuršvietienė, Lolita, Aušra Mongirdienė, Jurga Bernatonienė, Jurgita Šulinskienė e Inga Stanevičienė. "Selenium Anticancer Properties and Impact on Cellular Redox Status". Antioxidants 9, n. 1 (17 gennaio 2020): 80. http://dx.doi.org/10.3390/antiox9010080.
Testo completoAbstract (sommario):
(1) Background: In this review, we provide information published in recent years on the chemical forms, main biological functions and especially on antioxidant and prooxidant activities of selenium. The main focus is put on the impact of selenoproteins on maintaining cellular redox balance and anticancerogenic function. Moreover, we summarize data on chemotherapeutic application of redox active selenium compounds. (2) Methods: In the first section, main aspects of metabolism and redox activity of selenium compounds is reviewed. The second outlines multiple biological functions, asserted when selenium is incorporated into the structure of selenoproteins. The final section focuses on anticancer activity of selenium and chemotherapeutic application of redox active selenium compounds as well. (3) Results: optimal dietary level of selenium ensures its proper antioxidant and anticancer activity. We pay special attention to antioxidant activities of selenium compounds, especially selenoproteins, and their importance in antioxidant defence. It is worth noting, that data on selenium anticancer properties is still contraversive. Moreover, selenium compounds as chemotherapeutic agents usually are used at supranutritional doses. (4) Conclusions: Selenium play a vital role for many organism systems due to its incorporation into selenoproteins structure. Selenium possesses antioxidant activity at optimal doses, while at supranutritional doses, it displays prooxidant activity. Redox active selenium compounds can be used for cancer treatment; recently special attention is put to selenium containing nanoparticles.
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Mao, Xueyun, Chen Hua, Liang Yang, Yuhui Zhang, Zhengxi Sun, Lei Li e Tao Li. "The Effects of Selenium on Wheat Fusarium Head Blight and DON Accumulation Were Selenium Compound-Dependent". Toxins 12, n. 9 (6 settembre 2020): 573. http://dx.doi.org/10.3390/toxins12090573.
Testo completoAbstract (sommario):
Fusarium head blight (FHB) caused by Fusarium graminearum not only results in severe yield losses, but also contaminates wheat grains with deoxynivalenol (DON) toxins. Prevention and control of FHB and DON contamination rely mainly on resistant varieties and fungicides. Selenium (Se) is an essential element for humans and animals, and also a beneficial element for plants. In this work, four Se compounds, i.e., sodium selenite (Na2SeO3), sodium selenate (Na2SeO4), selenomethionine (SeMet) and selenocysteine (SeCys2), were supplemented in a trichothecene biosynthesis induction (TBI) solid medium at different dosages in in vitro experiments. The four Se compounds at the dosage of 20 mg∙L−1 were sprayed onto wheat spikes immediately after inoculation at anthesis. All four of the Se compounds significantly inhibited the mycelial growth and DON production in the in vitro experiment; however, in planta, their effects on FHB severity and toxin accumulation in grains were compound-dependent. SeMet consistently negatively regulated fungal growth and DON accumulation both in vitro and in planta, which could be a novel and proconsumer strategy for reducing the detriment of wheat FHB disease and DON accumulation.
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Krief, Alain, Cathy Delmotte e Catherine Colaux-Castillo. "Reactions involving inorganic compounds". Pure and Applied Chemistry 72, n. 9 (1 gennaio 2000): 1709–13. http://dx.doi.org/10.1351/pac200072091709.
Testo completoAbstract (sommario):
Selenium chemistry became, over the last 30 years, particularly useful for synthetic organic chemistry [1]. Inorganic as well as organic selenium compounds allow transformation which otherwise cannot be done or require much more drastic conditions to proceed. We have over the last 25 years explored the reactivity of elemental selenium as well as its inorganic and organic derivatives. We report here our recent finding concerning (i) organic diselenols and -diselenolates and (ii) the role of selenoxides in the enantioselective dihydroxylation of C,C double bonds using catalytic amounts of osmium tetroxide.
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Barbosa, Nilda Vargas, e João Batista T. da Rocha. "Influência do zinco sobre o efeito do selênio na atividade da enzima δ-ALA-D de fígado, rim e cérebro de camundongos adultos in vitro". Ciência e Natura 24, n. 24 (9 dicembre 2002): 49. http://dx.doi.org/10.5902/2179460x27224.
Testo completoAbstract (sommario):
Selenium is an essential dietary trace element and its deficiency can cause some pathologies such as cardiac diseases. However, investigations have evidencied the toxicologic effect of organic and inorganic selenium compounds in the organs and enzymes.The present work examined the toxic effect of selenium on δ-ALA-D an enzyme involved in the biosynthesis of tetrapyrrol heme. A possible protective role of zinc on inhibitory effect of selenium was also evaluated. The organic selenium compound, (CH3)2C (Seφ) (0CH3) caused a dose dependent inhibition of renal, hepatic and cerebral δ-ALA-D (p< 0.01). Also was evidencied that the selenium and zinc interaction not was able to restore the δ-ALA-D activity inhibited by selenium but increasing the inhibitory effect from the compound on the renal and cerebral enzyme.
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Mohamed, Dalia A., Awis Qurni Sazili, Loh Teck Chwen e Anjas Asmara Samsudin. "Effect of Microbiota-Selenoprotein on Meat Selenium Content and Meat Quality of Broiler Chickens". Animals 10, n. 6 (4 giugno 2020): 981. http://dx.doi.org/10.3390/ani10060981.
Testo completoAbstract (sommario):
Selenium (Se) is able to transform from inorganic to organic forms via many bacterial species. This feature is being considered for delivering more bioavailable selenium compounds such as selenocysteine and selenomethionine for human and animal diet. This study investigated the effects of bacterial selenoprotein versus inorganic Se on the carcass characteristics, breast meat selenium content, antioxidant status, and meat quality of broiler chickens. One hundred and eighty chicks were randomly allotted to five treatments of a basal diet supplemented with no Se, sodium selenite, Enterobacter cloacae Selenium (ADS1-Se), Klebsiella pneumoniae-Selenium (ADS2-Se), and Stenotrophomonas maltophilia-Selenium (ADS18-Se). The results showed that bacterial selenoprotein has the ability to deposit more Se in the breast meat compared to sodium selenite. Both Se sources reduced breast meat drip loss, cooking loss, shear force, and 2-thiobarbituric acid reactive substances (TBARS) significantly. It also increased total antioxidant (TAC) and glutathione peroxidase (GSH-Px) in comparison with the negative control. The highest activity of (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) was found in bacterial selenoprotein. In conclusion, bacterial selenoprotein is more efficient than sodium selenite in increasing the breast meat Se deposition and oxidative capacity of broiler chickens. Therefore, it can be effectively used to produce Se-rich meat as a functional food.
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Yang, W. H., e J. R. Yang. "Cytolysis caused by selenite uptake in the Bacillus subtilis". Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 368–69. http://dx.doi.org/10.1017/s0424820100169572.
Testo completoAbstract (sommario):
The toxic effects of selenium compounds on animals are well documented. However, the cytotoxic effects of these compounds are not well known. Using electron microscopy and atomic absorption spectrophotometry, we studied the effect of sodium selenite on the fine structure of Bacillus subtilis.Bacteria were cultured with sodium selenite in LB broth at 38°C in a shaker culture system. At concentrations of selenite greater than 1mM, an inhibitory effect on bacterial growth was seen during the first few hours of culture. Using the atomic absorption assay, no uptake of selenite into bacteria during the lag phase was demonstrable. However, during the exponential growth phase, a marked increase in the selenium content of the cell pellet was measured along with a decrease in selenite in the supernatant (Figure 1). A reddish discoloration of the culture media was observed which corresponded with increasing selenite uptake by bacteria. After 24 hours in culture, an increase in particle density and viscosity of the culture media was measured which suggested fragmentation of the bacteria resulting in the release of DNA into the media.
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Cipriano, Patriciani Estela, Rodrigo Fonseca da Silva, Cynthia de Oliveira, Alexandre Boari de Lima, Fabio Aurélio Dias Martins, Gizele Celante, Alcindo Aparecido dos Santos et al. "Sodium Selenate, Potassium Hydroxy-Selenide, Acetylselenide and Their Effect on Antioxidant Metabolism and Plant Nutrition and Yield in Sorghum Genotypes". Foods 12, n. 10 (17 maggio 2023): 2034. http://dx.doi.org/10.3390/foods12102034.
Testo completoAbstract (sommario):
Agronomic biofortification with selenium (Se) effectively reduces hidden hunger and increases the nutritional intake of Se in people and animals. Because sorghum is a staple diet for millions of people and is used in animal feed, it becomes a crop with biofortification potential. Consequently, this study aimed to compare organoselenium compounds with selenate, which is effective in numerous crops, and to assess grain yield, the effect in the antioxidant system, and macronutrient/micronutrient contents of different sorghum genotypes treated with Se, via foliar spray. The trials used a 4 × 8 factorial design, with four Se sources (control—without Se supply, sodium selenate, potassium hydroxy-selenide, acetylselenide) and eight genotypes (BM737, BRS310, Enforcer, K200, Nugrain320, Nugrain420, Nugrain430, and SHS410). The Se rate used was 0.125 mg plant−1. All genotypes reacted effectively to foliar fertilization with Se through sodium selenate. In this experiment, potassium hydroxy-selenide and acetylselenide showed low Se levels and lower Se uptake and absorption efficiency than selenate. Selenium fertilization increased grain yield and altered lipid peroxidation by malondialdehyde content, hydrogen peroxide content, catalase activity, ascorbate peroxidase, superoxide dismutase, and macronutrients and micronutrients content of the studied genotypes. In sum, biofortification with selenium led to an overall yield increase of sorghum plants and supplementation with selenium through sodium selenate was more efficient than organoselenium compounds, yet acetylselenide had a positive effect on the antioxidant system. Sorghum can be effectively biofortified through the foliar application of sodium selenate; however, studying the interaction between organic and inorganic Se compounds in plants is necessary.
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Zaki, Dr Remon M., Prof Adel M. Kamal El-Dean, Dr Nermin A. Marzouk, Prof Jehan A. Micky e Mrs Rasha H. Ahmed. "A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE". JOURNAL OF ADVANCES IN CHEMISTRY 12, n. 1 (26 ottobre 2015): 3910–18. http://dx.doi.org/10.24297/jac.v12i1.845.
Testo completoAbstract (sommario):
Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.
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Hao, Wenbin, Chunmei Tao, Tanveer M. Adyel, Junjie Zhao, Jun Hou, Lingzhan Miao e Yuan Zeng. "Effects of Selenium in Different Valences on the Community Structure and Microbial Functions of Biofilms". Water 14, n. 15 (2 agosto 2022): 2394. http://dx.doi.org/10.3390/w14152394.
Testo completoAbstract (sommario):
With the wide application of selenium (Se) in industrial production, different Se-based compounds (selenate and selenite) are produced and released into aquatic environments. The potential impacts of such Se compounds on the biofilms (a complex microbial aggregate in aquatic systems) need to be substantially explored. Herein, we investigated the responses of bacterial community diversity, composition and structure, and function of biofilms after 21 days of exposure to low concentrations (100 µg/L) and high concentrations (1 mg/L) of sodium selenate and sodium selenite, respectively. Distinct effects of selenium in different valences on the community structure and microbial functions of biofilms were observed. Compared with the controls, the addition of selenate and selenite solutions altered the richness of biofilms but not the diversity, which is dependent on the concentration and valences, with sodium selenite (1 mg/L) exhibiting a strong inhibition effect on community richness. Significant changes of community composition and structure were observed, with a significant increase in Proteobacteria (31.08–58.00%) and a significant decrease in Bacteroidetes (32.15–11.45%) after exposure to sodium selenite with high concentration. Also, different responses of gamma-Proteobacteria and alpha-Proteobacteria were observed between the sodium selenite and sodium selenate treatments. Moreover, results showed that sodium selenite could strengthen the function of the metabolism of biofilms, and the higher the concentration is, the more apparent the enhancement effect is. All these results suggested that the effects of different valence states of selenium were obvious, and sodium selenite with high concentration strongly changed the diversity, structure and function of biofilms.
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Batist, G., A. G. Katki, V. J. Ferrans e C. E. Myers. "The Role of Selenium Compounds in Cancer Therapy". Journal of the American College of Toxicology 5, n. 1 (gennaio 1986): 87–93. http://dx.doi.org/10.3109/10915818609140739.
Testo completoAbstract (sommario):
Experimental evidence is presented that demonstrates the impact of selenium on the effects of a variety of anticancer treatments, including chemotherapy and radiation. Selenium-dependent glutathione peroxidase can detoxify organic peroxides resulting from some of these treatments. Selenium deficiency has also been associated with significant changes in liver enzymes that activate some drugs and contribute to detoxification. Some forms of free selenium have cytotoxicity against a variety of tumor cell lines, both murine and human. Experimental data suggest that catalytic oxidation of cellular glutathione and reduction of molecular oxygen are part of the mechanism of this antitumor activity. This provides provocative possibilities for the inclusion of selenium into cancer therapy regimens.
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Groth, Sabrina, Christoph Budke, Susanne Neugart, Sofia Ackermann, Fenja-Sarah Kappenstein, Diemo Daum e Sascha Rohn. "Influence of a Selenium Biofortification on Antioxidant Properties and Phenolic Compounds of Apples (Malus domestica)". Antioxidants 9, n. 2 (24 febbraio 2020): 187. http://dx.doi.org/10.3390/antiox9020187.
Testo completoAbstract (sommario):
Biofortified apples seem to be a suitable produce. In this study, different selenium forms and application levels were applied to the two apple varieties ‘Golden Delicious’ and ‘Jonagold’, grown in the years 2017 and 2018 in order to increase the selenium uptake within a typical Western diet. It was shown that the biofortification, which was performed as a foliar application implemented in usual calcium fertilization, led to significantly increased selenium contents in the fruits. Furthermore, biofortification affected the total phenolic content (TPC), the polyphenol oxidase activity (PPO), as well as the antioxidant activity (AOA), the latter measured with the two well-known assays Trolox Equivalent Antioxidant Capacity Assay (TEAC) and Oxygen Radical Absorbance Capacity Assays (ORAC). The varying selenium forms and application levels showed a differing influence on the parameters mentioned before. Higher fertilizer levels resulted in higher selenium accumulation. It was found that PPO activity fluctuates less in biofortified apples. With regard to TPC, selenate led to higher amounts when compared to the untreated controls and selenite resulted in lower TPC. AOA analysis showed no clear tendencies as a result of the selenium biofortification. In the case of ‘Jonagold’, a higher AOA was generally measured when being biofortified, whereas, in the case of ‘Golden Delicious’, only one form of application led to higher AOA. Additionally, differences in the amount of major phenolic compounds, measured with High Performance Liquid Chromatography Mass Spectrometry (HPLC-DAD-ESI-MSn), were observed, depending on the conditions of the biofortification and the variety.
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KLEMENTYEV, M. I., M. G. CHABAEV, E. V. TUAEVA e R. V. NEKRASOV. "PRODUCTIVE POTENTIAL OF REARED YOUNG PIGS WHEN ENRICHING FEEDING DIETS WITH VARIOUS SELENIUM COMPOUNDS". PIG-BREEDING, n. 1 (2023): 35–39. http://dx.doi.org/10.37925/0039-713x-2023-1-35-39.
Testo completoAbstract (sommario):
To carry out scientific and economic experience, three groups of piglets-analogues at the age of 28 days (20 heads in each group) were selected, depending on the origin and live weight. The duration of the experiment was (62 days). According to the experimental scheme, the growing young pigs of the 1st control group as part of the SK-4 compound feed received 0.30 mg/kg of inorganic selenium feed in the form of sodium selenite, analogues from the 2nd and 3rd experimental groups received the same compound feed with the addition of 0.15 and 0.20 mg/kg of organic selenium, respectively. Feeding young pigs of the 2nd and 3rd experimental groups as part of the SK-4 compound feed of organic selenium in the amount of 0.15 and 0.20 mg/kg contributed to an increase in live weight and average daily gains at 60 and 90 days of age, respectively, by 7.46 g, 7.24 g and 12.3%, 12.1% and 8.4 g 8.3 g and 9.5%, 9.5% compared to control animals. The inclusion of various levels of organic selenium in the composition of the SK-4 compound feed contributed to an increase in the digestibility of all nutrients compared to the control. The inclusion of organic selenium in the growing young pigs of the experimental groups of 0.15 and 0.20 mg/kg of feed had a positive effect on the dynamics of morphological, biochemical, immunological parameters that cause an increase in the protective properties of the body. The greatest economic effect was obtained in the 2nd experimental group of piglets receiving 0.15 mg of B-Traxime Selenium per 1 kg of feed and amounted to 292.5 rubles per head.
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Lapkina, E. Z., E. E. Saveleva e N. A. Bulgakova. "Antiradical properties of selenium-enriched grain seedlings". Вестник Пермского университета. Серия «Биология»=Bulletin of Perm University. Biology, n. 1 (2021): 12–17. http://dx.doi.org/10.17072/1994-9952-2021-1-12-17.
Testo completoAbstract (sommario):
The results of studies of antiradical activity by the method of DPPG absorption by extracts of rye, wheat, and oat seedlings enriched with selenium from aqueous solutions of sodium Selenite 0.001, 0.005, 0.01, 0.05% concentrations within 24 hours. Selenium inhibits the rate of reaching the "plateau" of the DPPG absorption reaction, but increases the anti-radical activity of grain seedlings. The total content of phenolic compounds in grain extracts was determined spectrophotometrically. The influence of selenium on the growth processes of wheat, rye, and oats is shown. Concentrations of 0.001 and 0.005% have a stimulat-ing effect on the length of the roots and coleoptile of grain crops. At a concentration of 0.05%, selenium is deposited as granules in the cells of the germ of the grain. Oats are the most sensitive crop to selenium, and wheat and rye are promising as crops that can exhibit antiradical properties and source of organic forms of selenium.
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BRIVIBA, Karlis, Ivan ROUSSYN, Victor S. SHAROV e Helmut SIES. "Attenuation of oxidation and nitration reactions of peroxynitrite by selenomethionine, selenocystine and ebselen". Biochemical Journal 319, n. 1 (1 ottobre 1996): 13–15. http://dx.doi.org/10.1042/bj3190013.
Testo completoAbstract (sommario):
The effect of the selenium-containing compounds selenomethionine, selenocystine and ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one] on the oxidation of dihydrorhodamine 123 caused by peroxynitrite and on the nitration of 4-hydroxyphenylacetate by peroxynitrite was studied in comparison with their sulphur analogues methionine, cystine and ebsulfur [2-phenyl-1,2-benzisothiazol-3(2H)-one]. The selenocompounds protected dihydrorhodamine 123 from oxidation and 4-hydroxyphenylacetate from nitration more effectively than their sulphur analogues. Sodium selenite exhibited no effect. These observations are corollaries to the recent finding [Roussyn, Briviba, Masumoto and Sies (1996) Arch. Biochem. Biophys. 330, 216–218] that selenium-containing compounds are efficient in protecting against peroxynitrite-induced DNA single-strand breaks.
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Jobidon, Robert, e Marcel Prévost. "Potential Use of Quadrivalent Selenium as a Systemic Deer-Browsing Repellent: A Cautionary Note". Northern Journal of Applied Forestry 11, n. 2 (1 giugno 1994): 63–64. http://dx.doi.org/10.1093/njaf/11.2.63.
Testo completoAbstract (sommario):
Abstract This study evaluates the potential usefulness and toxicity of applying quadrivalent selenium (selenite ion) to the soil to discourage white-tailed deer from browsing conifer seedlings. After absorption by the root system and internal transport, organoselenium compounds are volatilizedby the foliage, and the characteristic garlic odor is hypothesized to protect coniferous tree seedlings from browsing damage. Results indicate that either 5, 17, or 24 months after treatment, selenized white spruce seedlings did not show significantly different deer-browsing damage from controlseedlings when deer numbers were high. Five and seventeen months after treatment, selenium had not leached but had accumulated in the top soil. Large-scale application of selenium may represent a potential environmental risk, hence we do not recommend use of selenite ion to prevent damagefrom deer-browsing of white spruce seedlings. North. J. Appl. For. 11(2):63-64.
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Kamal, Amna, Muhammad Adnan Iqbal e Haq Nawaz Bhatti. "Therapeutic applications of selenium-derived compounds". Reviews in Inorganic Chemistry 38, n. 2 (26 luglio 2018): 49–76. http://dx.doi.org/10.1515/revic-2018-0008.
Testo completoAbstract (sommario):
AbstractSelenium is a biocompatible element and participates in several biochemical reactions occurring in the human body. Its biocompatibility and minimal toxicity has attracted researchers to develop selenium-based drugs. Hence, recent developments on biomedical applications of selenium-based compounds have been discussed. A structure activity relationship has also been interpreted.
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Zagrodzki, Paweł, Agnieszka Wiesner, Monika Marcinkowska, Marek Jamrozik, Enrique Domínguez-Álvarez, Katarzyna Bierła, Ryszard Łobiński et al. "Relationships between Molecular Characteristics of Novel Organic Selenium Compounds and the Formation of Sulfur Compounds in Selenium Biofortified Kale Sprouts". Molecules 28, n. 5 (22 febbraio 2023): 2062. http://dx.doi.org/10.3390/molecules28052062.
Testo completoAbstract (sommario):
Due to problems with selenium deficiency in humans, the search for new organic molecules containing this element in plant biofortification process is highly required. Selenium organic esters evaluated in this study (E-NS-4, E-NS-17, E-NS-71, EDA-11, and EDA-117) are based mostly on benzoselenoate scaffolds, with some additional halogen atoms and various functional groups in the aliphatic side chain of different length, while one compound contains a phenylpiperazine moiety (WA-4b). In our previous study, the biofortification of kale sprouts with organoselenium compounds (at the concentrations of 15 mg/L in the culture fluid) strongly enhanced the synthesis of glucosinolates and isothiocyanates. Thus, the study aimed to discover the relationships between molecular characteristics of the organoselenium compounds used and the amount of sulfur phytochemicals in kale sprouts. The statistical partial least square model with eigenvalues equaled 3.98 and 1.03 for the first and second latent components, respectively, which explained 83.5% of variance in the predictive parameters, and 78.6% of response parameter variance was applied to reveal the existence of the correlation structure between molecular descriptors of selenium compounds as predictive parameters and biochemical features of studied sprouts as response parameters (correlation coefficients for parameters in PLS model in the range—0.521 ÷ 1.000). This study supported the conclusion that future biofortifiers composed of organic compounds should simultaneously contain nitryl groups, which may facilitate the production of plant-based sulfur compounds, as well as organoselenium moieties, which may influence the production of low molecular weight selenium metabolites. In the case of the new chemical compounds, environmental aspects should also be evaluated.
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Arodin Selenius, Lisa, Marita Wallenberg Lundgren, Rim Jawad, Olof Danielsson e Mikael Björnstedt. "The Cell Culture Medium Affects Growth, Phenotype Expression and the Response to Selenium Cytotoxicity in A549 and HepG2 Cells". Antioxidants 8, n. 5 (14 maggio 2019): 130. http://dx.doi.org/10.3390/antiox8050130.
Testo completoAbstract (sommario):
Selenium compounds influence cell growth and are highly interesting candidate compounds for cancer chemotherapy. Over decades an extensive number of publications have reported highly efficient growth inhibitory effects with a number of suggested mechanisms f especially for redox-active selenium compounds. However, the studies are difficult to compare due to a high degree of variations in half-maximal inhibitor concentration (IC50) dependent on cultivation conditions and methods to assess cell viability. Among other factors, the variability in culture conditions may affect the experimental outcome. To address this, we have compared the maintenance effects of four commonly used cell culture media on two cell lines, A549 and HepG2, evaluated by the toxic response to selenite and seleno-methylselenocysteine, cell growth and redox homeostasis. We found that the composition of the cell culture media greatly affected cell growth and sensitivity to selenium cytotoxicity. We also provided evidence for change of phenotype in A549 cells when maintained under different culture conditions, demonstrated by changes in cytokeratin 18 (CK18) and vimentin expression. In conclusion, our results have shown the importance of defining the cell culture medium used when comparing results from different studies.
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Ganther, H. E. "Pathways of Selenium Metabolism Including Respiratory Excretory Products". Journal of the American College of Toxicology 5, n. 1 (gennaio 1986): 1–5. http://dx.doi.org/10.3109/10915818609140731.
Testo completoAbstract (sommario):
Selenium occurs in a variety of different chemical forms in plants and animals. Plants take up inorganic forms of selenium and make numerous selenium analogs of sulfur compounds. Exclusion of selenium from proteins is characteristic of plant species able to tolerate high concentrations of selenium. Animals metabolize both inorganic and organic forms of selenium into biologically active compounds, including selenocysteine in glutathione peroxidase. Intermediary metabolism of selenium in animals characteristically involves reduction and methylation, resulting in the excretion of urinary or respiratory metabolites that include the trimethylselenonium ion and dimethylselenide. Some mechanisms for reduction and methylation of selenium in animals are discussed, as well as the effects of methylation on toxicity.
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Jablonska, Ewa, Qi Li, Edyta Reszka, Edyta Wieczorek, Kateryna Tarhonska e Tong Wang. "Therapeutic Potential of Selenium and Selenium Compounds in Cervical Cancer". Cancer Control 28 (1 gennaio 2021): 107327482110018. http://dx.doi.org/10.1177/10732748211001808.
Testo completoAbstract (sommario):
Cervical cancer is a common female cancer. It is strongly associated with human papillomavirus (HPV) infection. However, HPV infection alone is not sufficient to induce cervical cancer because its development is dependent on the coexistence of several factors that enable the virus to overcome the host immune system. These include individual genetic background, environmental factors, or diet, including dietary selenium intake. Selenium is an essential trace element with antiviral properties and has been shown to exert antitumor effects. Surprisingly, the role of selenium in cervical cancer has not been studied as intensively as in other cancers. Here, we have summarized the existing experimental data on selenium and cervical cancer. It may be helpful in evaluating the role of this nutrient in treatment of the mentioned malignancy as well as in planning further studies in this area.
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Kurek, Eliza, Magdalena Michalska-Kacymirow, Anna Konopka, Olga Kościuczuk, Anna Tomiak e Ewa Bulska. "Searching for Low Molecular Weight Seleno-Compounds in Sprouts by Mass Spectrometry". Molecules 25, n. 12 (22 giugno 2020): 2870. http://dx.doi.org/10.3390/molecules25122870.
Testo completoAbstract (sommario):
A fit for purpose analytical protocol was designed towards searching for low molecular weight seleno-compounds in sprouts. Complementary analytical techniques were used to collect information enabling the characterization of selenium speciation. Conceiving the overall characterization of the behavior of selenium, inductively plasma optical mass spectrometry (ICP-MS) was used to determine the total selenium content in entire sprouts as well as in selected extracts or chromatographic fractions. Then, high-performance liquid chromatography combined with ICP-MS (HPLC-ICP-MS) was used to evaluate the presence of inorganic and organic seleno-compounds, with the advantages of being very sensitive towards selenium, but limited by available selenium standard compounds. Finally, ultra-high performance liquid chromatography electrospray ionization triple quadrupole mass spectrometry (UHPLC-ESI-QqQ-MS/MS) and UHPLC-ESI-Orbitrap-MS/MS were used for the confirmation of the identity of selected compounds and identification of several unknown compounds of selenium in vegetable sprouts (sunflower, onion, radish), respectively. Cultivation of plants was designed to supplement sprouts with selenium by using solutions of selenium (IV) at the concentration of 10, 20, 40, and 60 mg/L. The applied methodology allowed to justify that vegetable sprouts metabolize inorganic selenium to a number of organic derivatives, such as seleno-methylselenocysteine (SeMetSeCys), selenomethionine (SeMet), 5′-seleno-adenosine, 2,3-DHP-selenolanthionine, Se-S conjugate of cysteine-selenoglutathione, 2,3-DHP-selenocysteine-cysteine, 2,3-DHP-selenocysteine-cysteinealanine, glutathione-2,3-DHP-selenocysteine, gamma-Glu-MetSeCys or glutamyl-glycinyl-N-2,3-DHP-selenocysteine.
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Pinheiro, F. J. A., R. S. Barros, D. M. Ribeiro, B. M. Lana Souza, De e T. G. Coelho. "Efficiency of selenium compounds in breaking dormancy of Townsville stylo seeds". Seed Science and Technology 36, n. 2 (1 luglio 2008): 271–82. http://dx.doi.org/10.15258/sst.2008.36.2.02.
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ISOZAKI, Akinori, Sachiko KUDOU, Hisomu NAGASHIMA e Tadao OKUTANI. "Determination of selenium in organic selenium compounds by ion chromatography." Bunseki kagaku 48, n. 5 (1999): 491–97. http://dx.doi.org/10.2116/bunsekikagaku.48.491.
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Kul’chitskii, N. A., e A. V. Naumov. "Modern State of Markets of Selenium and Selenium-Based Compounds". Izvestiya Vuzov. Tsvetnaya Metallurgiya (Proceedings of Higher Schools. Nonferrous Metallurgy) 1, n. 3 (17 giugno 2015): 40. http://dx.doi.org/10.17073/0021-3438-2015-3-40-48.
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