ChemInform Abstract: BIFUNCTIONAL CHELATING AGENTS. PART 1. 1-(P-AMINOPHENETHYL)ETHYLENEDIAMINETETRAACETIC ACID

1983 ◽  
Vol 14 (20) ◽  
Author(s):  
J. ALTMAN ◽  
N. SHOEF ◽  
M. WILCHEK ◽  
A. WARSHAWSKY
Keyword(s):  
Chelating Agents ◽  
Ethylenediaminetetraacetic Acid

scholarly journals Upregulation of the Renin–Angiotensin System Pathways and SARS-CoV-2 Infection: The Rationale for the Administration of Zinc-Chelating Agents in COVID-19 Patients

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 506
Author(s):  
Loris Zamai
Keyword(s):  
Chelating Agents ◽  
Ethylenediaminetetraacetic Acid ◽  
Current Knowledge ◽  
Clinical Manifestations ◽  
Renin Angiotensin System ◽  
Experimental Models ◽  
Zinc Metalloprotease ◽  
Previous Hypothesis ◽  
Zinc Metalloproteases

The article describes the rationale for the administration of zinc-chelating agents in COVID-19 patients. In a previous work I have highlighted that the binding of the SARS-CoV spike proteins to the zinc-metalloprotease ACE2 has been shown to induce ACE2 shedding by activating the zinc-metalloprotease ADAM17, which ultimately leads to systemic upregulation of ACE2 activity. Moreover, based on experimental models, it was also shown the detrimental effect of the excessive systemic activity of ACE2 through its downstream pathways, which leads to “clinical” manifestations resembling COVID-19. In this regard, strong upregulation of circulating ACE2 activity was recently reported in COVID-19 patients, thus supporting the previous hypothesis that COVID-19 may derive from upregulation of ACE2 activity. Based on this, a reasonable hypothesis of using inhibitors that curb the upregulation of both ACE2 and ADAM17 zinc-metalloprotease activities and consequent positive feedback-loops (initially triggered by SARS-CoV-2 and subsequently sustained independently on viral trigger) is proposed as therapy for COVID-19. In particular, zinc-chelating agents such as citrate and ethylenediaminetetraacetic acid (EDTA) alone or in combination are expected to act in protecting from COVID-19 at different levels thanks to their both anticoagulant properties and inhibitory activity on zinc-metalloproteases. Several arguments are presented in support of this hypothesis and based on the current knowledge of both beneficial/harmful effects and cost/effectiveness, the use of chelating agents in the prevention and therapy of COVID-19 is proposed. In this regard, clinical trials (currently absent) employing citrate/EDTA in COVID-19 are urgently needed in order to shed more light on the efficacy of zinc chelators against SARS-CoV-2 infection in vivo.

Mobility of Chelated Radionuclides in Engineered Concrete Barriers

1992 ◽  
Vol 294 ◽  
Author(s):  
Craig A. Dicke ◽  
Robert W. Smith
Keyword(s):  
Citric Acid ◽  
Chelating Agents ◽  
Ethylenediaminetetraacetic Acid ◽  
Cobalt Complexes ◽  
Alkaline Ph ◽  
Pore Fluids ◽  
Concrete Barriers ◽  
Equilibrium Speciation ◽  
Low Level Radioactive Waste

ABSTRACTConcrete is a major component in many low-level radioactive waste (LLW) disposal facilities. The use of concrete is widespread because of its physical and structural properties and because it provides geochemical control on metal and radionuclide releases. Organic compounds are often disposed with radionuclides in LLW disposal facilities. Interactions between radionuclides and chelating agents must be evaluated to estimate mobility of radionuclides in concrete vaults. This paper quantifies the effects of two common organic components [citric acid and ethylenediaminetetraacetic acid (EDTA)] on radionuclide mobility in concrete barriers by using equilibrium geochemical calculations.Equilibrium speciation calculations indicate that some radionuclides are chelated in groundwater (pH 7) but are destabilized in the highly alkaline (pH 13) concrete pore fluids. Radionuclides complexed by EDTA and citrate are replaced by calcium in the concrete pore fluids. In addition, the citrate nuclide complex reacts to form uncomplexed citrate in concrete pore fluids. The chemical performance of concrete LLW disposal facilities should not be compromised by small amounts of chelating agents disposed with some radionuclides. However, EDTA may form significant nickel and cobalt complexes above the pH important in the long-term service life of concrete barriers.

Change of resistance to lysozyme and ultrasonic disintegration of the mycelium of Streptomyces griseus under the influence of chelating agents and polyvalent cations

1968 ◽  
Vol 14 (7) ◽  
pp. 769-773 ◽  
Author(s):  
F. Szeszák ◽  
G. Szabó ◽  
J. Erdel ◽  
F. Müller
Keyword(s):  
Cell Wall ◽  
Life Cycle ◽  
Submerged Culture ◽  
Chelating Agents ◽  
Ethylenediaminetetraacetic Acid ◽  
Streptomyces Griseus ◽  
Enhanced Resistance ◽  
Polyvalent Cations

Mycelia of Streptomyces griseus strain No. 52-1 from a 2-day submerged culture pretreated with ethylenediaminetetraacetic acid (EDTA) were digested with lysozyme. The sensitivity of younger vegetative hyphae to lysozyme increased while that of older reproductive hyphae remained almost unchanged.EDTA or borate pretreatment increased resistance to ultrasonic disintegration in the case of 96-h mycelia from submerged culture. EDTA was most effective at a concentration of 10−5 M.The enhanced resistance to ultrasonic disintegration can be reversed by Mg2+ and Al3+ in a concentration of 10−5 M, while Ca2+ ions are ineffective.These results suggest the existence of a polyvalent-ion-dependent layer in the cell wall of streptomycetes. Such a layer would be exterior to the mucopeptide layer. Its thickness changes during the life cycle and it is most prominent in younger vegetative hyphae.

scholarly journals Liposomes containing chelating agents. Cellular penetration and a possible mechanism of metal removal.

1975 ◽  
Vol 65 (1) ◽  
pp. 112-122 ◽  
Author(s):  
Y E Rahman ◽  
B J Wright
Keyword(s):  
Kupffer Cells ◽  
Chelating Agents ◽  
Metal Removal ◽  
Ethylenediaminetetraacetic Acid ◽  
Morphological Changes ◽  
Close Contact ◽  
Physiological Role ◽  
Cellular Membrane ◽  
Liposomal Membrane ◽  
Autophagic Vacuoles

Electron microscope studies were done on mouse liver, from 5 min to 8 wk after an intravenous injection of liposomes containing ethylenediaminetetraacetic acid (EDTA). Livers of mice receiving an injection of liposomes containing KCL instead of EDTA or an injection of a solution of EDTA were also examined. Liposomes were shown to be phagocytized by hepatocytes as well as by Kupffer cells within minutes after the injection. Initially, there was a close contact between the liposomal membrane and the cellular membrane, followed by an invagination of the latter and the formation of a distinct vesicle surrounding a single liposome or a cluster of several liposomes. No fusion between the liposomal membrane and the cell membrane was observed. Between 15 min and 6 h after liposome injection, the Kupffer cells were found to have an increased number of lysosomes and autophagic vacuoles. Within the latter, morphologically intact liposomes or remnants of liposomes could be seen. At 12 h after injection, a striking increase in macrophages was observed in the liver sinusoids of EDTA-liposome-injected mice, but not in those of KCl-liposome-injected mice. Within the macrophages, remnants of liposomes occasionally could be observed. However, the origin and the physiological role of these cells are unknown. In the hepatocytes, morphological changes were first observed 24 h after injection; there were large numbers of autophagic vacuoles, and some cells showed extensive areas of focal cytoplasmic degeneration. The morphology of the liver cells returned to normal about 7 days after injection. No morphological changes were observed in livers of mice receiving EDTA solution without liposomes. A possible mechanism by which the liposome-encapsulated chelating agents can successfully remove intracellular toxic metals is discussed. The use of liposomes as carriers seems to be a useful tool for intracellular delivery of chelating agents or drugs in general.

scholarly journals Enhanced Degradation of Phenol by a Fenton-Like System (Fe/EDTA/H2O2) at Circumneutral pH

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 474 ◽  
Author(s):  
Selamawit Ashagre Messele ◽  
Christophe Bengoa ◽  
Frank Erich Stüber ◽  
Jaume Giralt ◽  
Agustí Fortuny ◽  
...  
Keyword(s):  
Chelating Agents ◽  
Ethylenediaminetetraacetic Acid ◽  
Chelating Agent ◽  
Nitrilotriacetic Acid ◽  
Molar Ratio ◽  
Phenol Removal ◽  
Stoichiometric Ratio ◽  
Initial Ph ◽  
Phenol Conversion ◽  
Circumneutral Ph

This work deals with the degradation of phenol based on the classical Fenton process, which is enhanced by the presence of chelating agents. Several iron-chelating agents such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), diethylenetriamine pentaacetic acid (DTPA), and ethylenediamine-N,N’-diacetic acid (EDDA) were explored, although particular attention was given to EDTA. The effect of the molar ligand to iron ratio, EDTA:Fe, initial pH, and temperature on the oxidation process was studied. The results demonstrate that the proposed alternative approach allows the capacity for degrading phenol to be extended from the usual acidic pH (around 3.0) to circumneutral pH range (6.5–7.5). The overall feasibility of the process depends on the concentration of the chelating agent and the initial pH of the solution. The maximum phenol conversion, over 95%, is achieved using a 0.3 to 1 molar ratio of EDTA:Fe, stoichiometric ratio of H2O2 at an initial pH of 7.0, and a temperature of 30 °C after 2 hours of reaction, whereas only 10% of phenol conversion is obtained without EDTA. However, in excess of ligand (EDTA:Fe > 1), the generation of radicals seems to be strongly suppressed. Improvement of the phenol removal efficiency at neutral pH also occurs for the other chelating agents tested.

The Role of Siderophores in the Transport of Radionuclides

1992 ◽  
Vol 294 ◽  
Author(s):  
Larry E. Hersman ◽  
Philip D. Palmer ◽  
David E. Hobart
Keyword(s):  
Ionic Radius ◽  
Chelating Agents ◽  
Ethylenediaminetetraacetic Acid ◽  
Binding Constants ◽  
Subsurface Environment ◽  
Naturally Occurring ◽  
Trisodium Salt ◽  
Aerobic Soil ◽  
Soil And Water

ABSTRACTIron exists in aerobic soil and water environments most commonly as insoluble Fe(III). Siderophores are powerful, microbially produced chelating agents that are used to mobilize the insoluble Fe(III) cation. Over 80 siderophores have been isolated and characterized, with some reportedly having iron-binding constants as high as 1052. Fe(III) and Pu(IV) are similar in their charge/ionic radius ratio (4.6 and 4.2, respectively); therefore, Pu(IV) may serve as analog to Fe(III). It is possible that some radioactive wastes could be chelated by naturally occurring siderophores, thereby altering the transport rates of those elements through the subsurface environment. This investigation wn 9 initiated to investigate that possibility. The binding of 239Pu(IV) by four chelating agents is reported in this paper: a siderophore isolated and purified from a Pseudomonas sp.; desferal, a ferrioxamine siderophore commonly used for deferration therapy; EDTA, ethylenediaminetetraacetic acid; and, citrate, trisodium salt.

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