Chelating Agent Ethylenediaminetetraacetic Acid Research Articles

EDTA: Ethylene Diamine Tetra Acetic Acid – A Review

Chelation therapists around the world incorporate chelation therapies into their daily medical practice, frequently using EDTA (ethylene diamine tetra acetic acid) compounds, unaware of the chemical difference of the various EDTA chelating agents. With this information, we aim to clarify the different mode of action of the EDTAs, including their appropriate medical use. In the USA, medical practitioners promote EDTA chelation, often as an alternative to conventional treatments for a variety of chronic diseases, including vascular problems. German nonmedical professionals use the ‘CaEDTA push’ as promoted by US web pages, although this is against standard protocol. CaEDTA has been FDA- approved for lead intoxication only, and Na2EDTA has not been approved for the treatment of cardiovascular disease. These facts are often overlooked. Misunderstandings increase the risk of iatrogenic accidents. This information aims to prevent this.

Rationale for the Successful Management of EDTA Chelation Therapy in Human Burden by Toxic Metals.

Exposure to environmental and occupational toxicants is responsible for adverse effects on human health. Chelation therapy is the only procedure able to remove toxic metals from human organs and tissue, aiming to treat damage related to acute and/or chronic intoxication. The present review focuses on the most recent evidence of the successful use of the chelating agent ethylenediaminetetraacetic acid (EDTA). Assessment of toxic-metal presence in humans, as well as the rationale of EDTA therapy in cardiovascular and neurodegenerative diseases, is reported.

Assessing Methods of Removing Metals from Wastewater: The Effect of Ferric Chloride Addition on Metal Speciation and Removal

The presence of cationic pollutant metals in municipal wastewater effluent is a concern because stringent discharge requirements cannot always be met with conventional treatment methods. Attempts to improve metal removal are often unsuccessful because a significant fraction of the cationic metals are complexed by the synthetic chelating agent ethylenediamine tetraacetic acid (EDTA). To identify practical approaches for improving metal removal, an analytical method for measuring metal-EDTA complexes was used to survey metal speciation at a series of wastewater treatment plants. Following these analyses, bench-scale experiments were conducted. The survey data indicated that pollutant metal-EDTA complexes account for a significant fraction of the dissolved metals in wastewater. The bench-scale studies indicated that ferric chloride addition improves the removal of copper and zinc by approximately 20%. To test the results of the bench-scale experiments, a full-scale experiment was conducted by interrupting chemical addition at a municipal wastewater treatment plant that normally adds ferric chloride during primary treatment. Results indicated that ferric chloride addition had a slight impact on metal speciation but no effect on metals removal. The lack of an effect was attributed to changes in metal speciation that occurred during primary treatment irrespective of ferric chloride addition. This title belongs to WERF Research Report Series ISBN: 9781843396949 (Print) ISBN: 9781780404387 (eBook)

Purification and characterization of a novel chitinase from Trichosanthes dioica seed with antifungal activity

Chitinases are a group of enzymes that show differences in their molecular structure, substrate specificity, and catalytic mechanism and widely found in organisms like bacteria, yeasts, fungi, arthropods actinomycetes, plants and humans. A novel chitinase enzyme (designated as TDSC) was purified from Trichosanthes dioica seed with a molecular mass of 39±1kDa in the presence and absence of β-mercaptoethanol. The enzyme was a glycoprotein in nature containing 8% neutral sugar. The N-terminal sequence was determined to be EINGGGA which did not match with other proteins. Amino acid analysis performed by LC-MS revealed that the protein was rich in leucine. The enzyme was stable at a wide range of pH (5.0–11.0) and temperature (30–90°C). Chitinase activity was little bit inhibited in the presence of chelating agent EDTA (ethylenediaminetetraaceticacid), urea and Ca2+. A strong fluorescence quenching effect was found when dithiothreitol and sodium dodecyl sulfate were added to the enzyme. TDSC showed antifungal activity against Aspergillus niger and Trichoderma sp. as tested by MTT assay and disc diffusion method.

Efficacy of chelation therapy to remove aluminium intoxication

There is a distinct correlation between aluminium (Al) intoxication and neurodegenerative diseases (ND). We demonstrated how patients affected by ND showing Al intoxication benefit from short-term treatment with calcium disodium ethylene diamine tetraacetic acid (EDTA) (chelation therapy). Such therapy further improved through daily treatment with the antioxidant Cellfood. In the present study we examined the efficacy of long-term treatment, using both EDTA and Cellfood. Slow intravenous treatment with the chelating agent EDTA (2g/10mL diluted in 500mL physiological saline administered in 2h) (chelation test) removed Al, which was detected (using inductively coupled plasma mass spectrometry) in urine samples collected from patients over 12h. Patients that revealed Al intoxication (expressed in μg per g creatinine) underwent EDTA chelation therapy once a week for ten weeks, then once every two weeks for a further six or twelve months. At the end of treatment (a total of 22 or 34 chelation therapies, respectively), associated with daily assumption of Cellfood, Al levels in the urine samples were analysed. In addition, the following blood parameters were determined: homocysteine, vitamin B12, and folate, as well as the oxidative status e.g. reactive oxygen species (ROS), total antioxidant capacity (TAC), oxidized LDL (oxLDL), and glutathione. Our results showed that Al intoxication reduced significantly following EDTA and Cellfood treatment, and clinical symptoms improved. After treatment, ROS, oxLDL, and homocysteine decreased significantly, whereas vitamin B12, folate and TAC improved significantly. In conclusion, our data show the efficacy of chelation therapy associated with Cellfood in subjects affected by Al intoxication who have developed ND.

Chelating-Agent Enhanced Oil Recovery for Sandstone and Carbonate Reservoirs

Summary Recently low-salinity waterflooding was introduced as an effective enhanced-oil-recovery (EOR) method in sandstone and carbonate reservoirs. The recovery mechanisms that use low-salinity-water injection are still debatable. The suggested possible mechanisms are: wettability alteration, interfacial-tension (IFT) reduction, multi-ion exchange, and rock dissolution. In this paper, we introduce a new chemical EOR method for sandstone and carbonate reservoirs that will give better recovery than the low-salinity-water injection without treating or diluting seawater. In this study, we introduce a new chemical EOR method that uses chelating agents such as ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), and diethylenetriaminepentaacetic acid (DTPA) at high pH values. This is the first time for use of chelating agents as standalone EOR fluids. Coreflood experiments, interfacial and surface tensions, and zeta-potential measurements are performed with DTPA, EDTA, and HEDTA chelating agents. The chelating-agent concentrations used in the study were prepared by diluting the initial concentration of 40 wt% with seawater and injecting it into Berea-sandstone and Indiana-limestone cores of a 6-in. length and a 1.5-in. diameter saturated with crude oil. The coreflooding experiments were performed at 100°C and a 1,000-psi backpressure. Low-salinity-water and seawater injections caused damage to the reservoir because of the calcium sulfate scale deposition during the flooding process. The newly introduced EOR method did not cause calcium sulfate precipitation, and the core permeability was not affected. The core permeability was measured after the flooding process, and the final permeability was higher than the initial permeability in the case of chelating-agent injection. The coreflooding effluent was analyzed for cations with the inductively coupled plasma (ICP) spectroscopy to explain the dissolution-recovery mechanism. The effect of iron minerals on the rock-surface charge was investigated through the measurements of zeta potential for different rocks containing different iron minerals. HEDTA and EDTA chelating agents at 5 wt% concentration prepared in seawater were able to recover more than 20% oil from the initial oil in place from sandstone and carbonate cores. ICP measurements supported the rock-dissolution mechanism because the calcium, magnesium, and iron concentrations in the effluent samples were more than those in the injected fluids. The IFT-reduction mechanism was confirmed by the low IFT values obtained in the case of chelating agents. The type and concentration of chelating agents affected the IFT value. Higher concentrations yielded lower IFT values because of the increase in carboxylic-group concentration. We found that the high-pH chelating agents increased the negative value of zeta potential, which will change the rock toward more water-wet.

Modeling Flow of Chelating Agents During Stimulation of Carbonate Reservoirs

Chelating agents such as ethylenediaminetetraacetic acid (EDTA) and hydroxy ethylene diamine triacetic acid (HEDTA) have been used as stand-alone stimulation fluids. These fluids can be used to stimulate water injectors, oil, or gas producers. In this study, an analytical model was developed to describe the flow of HEDTA and EDTA chelating agents and propagation inside calcite formations. The analytical model can be used as a pre-design tool before the treatments. The developed model can be used to predict the volume of the chelant required to create wormholes in calcite formations at different temperatures. The temperature affects the diffusion coefficient of the chelating agent, wormholing rate, and wormhole shape and size. The dissolving power of different forms of HEDTA can be determined using the model. The optimum injection rate based on optimum wormholing conditions was identified. Also, the model can be used to predict the wormholing rate of different chelating agents in calcite formations. The analytical model can be used to predict the performance of the chelating agent in calcite stimulation. The volume of chelating agent required to stimulate calcite formation per foot thickness was determined using the developed model. The optimum injection rate was determined for different chelating agents using the model, and the results were compared with experimental results from previous work and there was a good agreement between the measured and the predicted values. The model can be used to determine the best stimulation fluid based on the temperature and fracture pressure of the target zones.

Role of extracellular calcium and mitochondrial oxygen species in psychosine-induced oligodendrocyte cell death.

Globoid cell leukodystrophy (GLD) is a metabolic disease caused by mutations in the galactocerebrosidase (GALC) gene. GALC is a lysosomal enzyme whose function is to degrade galacto-lipids, including galactosyl-ceramide and galactosyl-sphingosine (psychosine, PSY). GALC loss of function causes progressive intracellular accumulation of PSY. It is widely held that PSY is the main trigger for the degeneration of myelinating cells and progressive white-matter loss. However, still little is known about the molecular mechanisms by which PSY imparts toxicity. Here, we address the role of calcium dynamics during PSY-induced cell death. Using the human oligodendrocyte cell line MO3.13, we report that cell death by PSY is accompanied by robust cytosolic and mitochondrial calcium (Ca2+) elevations, and by mitochondrial reactive oxygen species (ROS) production. Importantly, we demonstrate that the reduction of extracellular calcium content by the chelating agent ethylenediaminetetraacetic acid can decrease intra-mitochondrial ROS production and enhance cell viability. Antioxidant administration also reduces mitochondrial ROS production and cell loss, but this treatment does not synergize with Ca2+ chelation. Our results disclose novel intracellular pathways involved in PSY-induced death that may be exploited for therapeutic purposes to delay GLD onset and/or slow down its progression.

Partial characterization of Acanthamoeba castellanii (T4 genotype) DNase activity.

The deoxyribonuclease (DNase) activities of Acanthamoeba castellanii belonging to the T4 genotype were investigated. Using zymographic assays, the DNase activities had approximate molecular masses of 25 and 35 kDa. A. castellanii DNases exhibited activity at wide-ranging temperature of up to 60 °C and at pH ranging from 4 to 9. The DNases activities were unaffected by proteinase-K treatment, divalent cations such as Ca(++), Cu(++), Mg(++), and Zn(++), or divalent cation chelating agent ethylenediaminetetraacetic acid (EDTA) or sodium dodecyl sulfate (SDS). The non-reliance on divalent cations and homology data suggests that A. castellanii DNases belong to the class of eukaryotic lysosomal DNase II but exhibit robust properties. The DNases activity in A. castellanii interfered with the genomic DNA extraction. Extraction methods involving EDTA, SDS, and proteinase-K resulted in low yield of genomic DNA. On the other hand, these methods resulted in high yield of genomic DNA from human cells suggesting the robust nature of A. castellanii DNases that are unaffected by reagents normally used in blocking eukaryotic DNases. In contrast, the use of chaotropic agent such as guanidine thiocyanate improved the yield of genomic DNA from A. castellanii cells significantly. Further purification and characterization of Acanthamoeba DNases is needed to study their non-classic distinct properties and to determine their role in the biology, cellular differentiation, cell cycle progression, and arrest of Acanthamoeba.

Determination of picomolar beryllium levels in seawater with inductively coupled plasma mass spectrometry following silica-gel preconcentration

A robust and rapid method for the determination of natural levels of beryllium (Be) in seawater was developed to facilitate mapping Be concentrations in the ocean. A solid-phase extraction method using a silica gel column was applied for preconcentration and purification of Be in seawater prior to determination of Be concentrations with inductively coupled plasma mass spectrometry (ICP-MS). Be was quantitatively adsorbed onto silica gel from solutions with pH values ranging from 6.3 to 9, including natural seawater. The chelating agent ethylenediamine tetraacetic acid was used to remove other ions in the seawater matrix (Na, Mg, and Ca) that interfere with the ICP-MS analysis. The reproducibility of the method was 3% based on triplicate analyses of natural seawater samples, and the detection limit was 0.4pmolkg−1 for 250mL of seawater, which is sufficient for the analysis of seawater in the open ocean. The method was then used to determine the vertical profile of Be in the eastern North Pacific Ocean, which was found to be a recycled-type profile in which the Be concentration increased with depth from the surface (7.2pmolkg−1 at <200m) to deep water (29.2pmolkg−1 from 3500m to the bottom).

Suitability of Ag‐agar gel for the micro‐extraction of organic dyes on different substrates: the case study of wool, silk, printed cotton and a panel painting mock‐up

A surface‐enhanced Raman spectroscopy (SERS) substrate made of agar gel coupled with silver nanoparticles has been applied to the micro‐extraction and the ultra‐sensitive detection of dyes on pieces of textile of different nature (silk, wool, and printed cotton) and on a mock‐up panel painting. In particular, the Ag‐agar gel substrate previously developed has been improved by the addition of the chelating agent ethylenediaminetetraacetic acid (EDTA), which has been found to play an important role as a stabilizer of the nanocomposite matrix and for the improvement of the micro‐extractive performances of the gel. The system has been confirmed to be non‐destructive and minimally invasive, showing a better capability of trapping the dye molecules inside its structure. Ag‐agar gel‐EDTA has been an invaluable and powerful tool for the characterization of the dye present in a printed cotton sample of unknown chemical composition. SERS analyses, performed on the dried cube of gel following extraction on the sample, have allowed for the identification of the dye. SERS results have been corroborated by high‐performance liquid chromatography analyses. The possibility of easily detecting compounds at very low concentration coupled with the high sensitivity of SERS makes this technique a valid and versatile method for the non‐destructive recognition of chemicals in works of art. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Aluminium involvement in neurotoxicity.

The aetiology of neurodegenerative diseases (ND) seems to involve susceptibility genes and environmental factors. Toxic metals are considered major environmental pollutants. Following our study of a case of multiple sclerosis (MS) improvement due to removal of aluminium (Al) and other toxic metals, we have examined the possible relationship between Al intoxication and ND. We used the slow intravenous treatment with the chelating agent EDTA (calcium disodium ethylene diamine tetraacetic acid) (chelation test) to remove Al and detected it in the urine collected from the patients for 12 hours. Patients affected by MS represented 85.6% of total ND. Al was present in 44.8% of cases comprehensive of ND and healthy patients. Al levels were significantly higher in ND patients than in healthy subjects. We here show that treatment of patients affected by Al burden with ten EDTA chelation therapies (EDTA intravenous administration once a week) was able to significantly reduce Al intoxication.

Characterization of a new oxidant-stable serine protease isolated by functional metagenomics

A novel serine protease gene, SBcas3.3, was identified by functional screening of a forest-soil metagenomic library on agar plates supplemented with AZCL-casein. Overproduction in Escherichia coli revealed that the enzyme is produced as a 770-amino-acid precursor which is processed to a mature protease of ~55 kDa. The latter was purified by affinity chromatography for characterization with the azocasein substrate. The enzyme proved to be an alkaline protease showing maximal activity between pH 9 and 10 and at 50°C. Treatment with the chelating agent ethylenediaminetetraacetic acid irreversibly denatured the protease, whose stability was found to depend strictly on calcium ions. The enzyme appeared relatively resistant to denaturing and reducing agents, and its activity was enhanced in the presence of 10 ml/l nonionic detergent (Tween 20, Tween 80, or Triton X-100). Moreover, SBcas3.3 displayed oxidant stability, a feature particularly sought in the detergent and bleaching industries. SBcas3.3 was activated by hydrogen peroxide at concentrations up to 10 g/l and it still retained 30% of activity in 50 g/l H2O2.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-410) contains supplementary material, which is available to authorized users.

Advancement in Infection Control of Opportunistic Pathogen (Aspergillus spp.): Adjunctive Agents

There is continuous emergence of resistant strains which leads to urgent need to discover new antifungal agents. The investigation of adjunctive agents for antifungal activity might help to optimize the therapy for Invasive Aspergillosis (IA). The chelating agents Ethylenediamine Tetraacetic Acid (EDTA) & Disodium salt of EDTA (DiEDTA) as adjunct to antifungal drugs have been investigated against 8 pathogenic isolates of Aspergillus spp. The MIC (Minimum Inhibitory Concentration) found by DDA (Disc Diffusion Assay) is 7.50-15.0 μg/disc; by MDA (Microbroth Dilution Assay) is 30.0-49.13 μg/ml & SGIA (Spore germination Inhibition Assay) is 30.0-49.13 μg/ml. Moreover, these agents did not show any toxicity up to a concentration of 312.5 μg/ml. The antifungal activity is also confirmed by another method i.e time kill curve analysis. While these agents were ten times less active than gold standard drug (Amphotericin B; AmpB) but eight times less toxic than AmpB. This leads to preliminary investigation of in vitro combination of chelating agents with antifungal drugs (Polyenes & Azoles) by DDA. These combinations showed a significant increase in zone of inhibition in contrast to single drug used. This preliminary work with chelating agents suggest that EDTA as an enhancing agent with antifungal properties in combination with antifungal drugs can be used in pharmaceutical preparations. Further investigation is in progress.

Effects of EDTA on Cr+3 Uptake, Accumulation, and Biomass in Nasturtium officinale (Watercress)

A pot study was used to examine the effects of ethylenediaminetetraacetic acid (EDTA) on the growth potential, uptake, and mobilization of Cr by Watercress (Nasturtium officinale) in contaminated water at different concentration levels of the chelating agent EDTA (0, 10-5, and 10-4 M) and four concentration levels of Cr (0, 1, 3, and 10 mgL-1). The EDTA resulted in more solubilization of Cr in water. The application of EDTA 15 d prior to harvest increased the amount of Cr accumulated in watercress with more Cr accumulated by the plants from the media. Nasturtium officinale accumulated high Cr concentration (317 mgkg -1 ) in the root at a concentration of 10 mgL -1 Cr 3+ and 10 4- M EDTA after 15 d growth. The application of EDTA had inhibitory effects on the root and shoot dry biomass compared with that in the

Non-Enzymatic Hydrolysis of RNA in Workers of the AntNylanderia pubens

During preparation of total RNA from Nylanderia pubens (Forel) (Hymenoptera: Formicidae) workers for use in expression library construction, severe RNA degradation consistently occurred. This degradation was masked by spectrophotometric analysis but clearly evident by microfluidic-based assay. Although not specifically identified, the degrading entity was endogenous and localized to the abdomen (terminal abdominal segments) of adult ants. RNA degradation was not observed in preparations of larvae, non-melanized pupae, or eggs. Various RNase and protease inhibitors had no protective effect. However, the metal chelating agent ethylenediaminetetraacetic acid prevented RNA degradation and provides insight into the occurrence.

Extraction of Nickel from Spent Catalyst Using Biodegradable Chelating Agent EDDS

Literature suggests that ethylene-diamine-tetraacetic acid (EDTA) has been proved as a successful chelating agent for the extraction of metals from soils and spent catalysts. EDTA, however, is quite persistent in the environment due to its low biodegradability, thus its use becomes a matter of environmental concern. Therefore, to minimize the potential environmental risks, a new chelating agent [S,S]-ethylene-diamine-disuccinic-acid ([S,S]-EDDS) can be considered as an environmentally benign substitute for EDTA due to its easy biodegradation capability. The present study focuses on the effectiveness of biodegradable chelating agent [S,S]-EDDS for extraction of nickel from the spent catalyst of fertilizer industry. Experiments were carried out in batch mode under reflux conditions and process design parameters were optimized to maximize the extraction efficiency. Ni extraction of 84% was attained at optimum reaction condition in one cycle run. Dechelation of Ni-EDDS complex was performed at pH 5 where more than 96% EDDS was recovered. Results of the present study were compared with the previously studied chelating agent EDTA at optimum reaction conditions reported in literature. It was observed that [S,S]-EDDS requires a narrower pH range as compared to EDTA for chelation–dechelation process. Thus milder reaction conditions were employed for metal extraction using EDDS which is favorable to select the material of construction of equipment, in addition to the added advantage of biodegradability. Kinetic study was also performed for the noncatalyzed extraction process using shrinking core model and the process was found to be diffusion controlled under experimental conditions.

A highly selective fluorescence sensor for Tin (Sn4+) and its application in imaging live cells

A naphthalimide-rhodamine B derivative was synthesized as a fluorescence turn-ON chemodosimeter for Sn(4+). A colour change and marked enhancement of fluorescence was found in the presence of Sn(4+), Cu(2+) and Cr(3+) due to the ring open reaction of rhodamine and a fluorescence resonance energy transfer process. Addition of the strong chelating agent ethylenediaminetetraacetic acid disodium salt (EDTA) partly released the cation from the complex with Sn(4+) and restored the yellow fluorescence. In addition, the compound can be used as a fluorescent probe for Sn(4+) in biological systems and may act as a tool with which to study the physiological functions of tin or pathogenesis in the human body.

The release and extraction of lanthanide ions from metal-encoded poly (styrene-co-methacrylic acid) microspheres

This article describes a systematic study of ion release, carried out on lanthanide-encoded polystyrene-co-methacrylic acid (P(S-MAA)) and polystyrene-co-acrylic acid (P(S-AA)) copolymer particles, which were synthesized by two-stage or three-stage dispersion polymerizations. These particles with different levels of lanthanide (Ln) ion content and containing several different types of Ln ions were dispersed in normal buffer media, namely 2-(N-morpholino)ethanesulfonic acid (MES), phosphate buffered saline solution (PBS), ammonium acetate (AmAc) and buffers containing strong chelating molecules like ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA). Traditional inductively coupled plasma mass spectrometry (ICP-MS) was employed to follow the loss of ions into the aqueous medium as a function of time. The release behavior of the Ln ions were compared. In MES and PBS buffers at neutral pH, and AmAc at pH 9.0, there was essentially no significant loss of Ln ions from the particles to the buffer. When the chelating agents EDTA or DTPA were present in the buffer, the loss of Ln ions was more prominent, but less than 15% after 8 weeks under stirring. The differences among the different samples were small. Considering the ability of EDTA and DTPA to remove Ln ions from the particles and the fact of minimal ion release in the presence of PBS buffer, we infer that the ion loss is a more active process involving the EDTA or DTPA molecules. The main conclusion is that in the absence of strong chelating agents, these particles are stable against ion leakage, even upon prolonged storage and stirring. This is of great importance for their application in bead-array biological assays based on mass cytometry detection.

Soil washing of chromium- and cadmium-contaminated sludge using acids and ethylenediaminetetra acetic acid chelating agent

In this research, the effect of soil washing in the removal of chromium- and cadmium-contaminated sludge samples collected from Pond 2 of the Tehran Oil Refinery was investigated. These metals are considered as hazardous substances for human health and the environment. The carcinogenicity of chromate dust has been established for a long time. Cadmium is also a potential environmental toxicant. This study was carried out by collecting sludge samples from different locations in Pond 2. Soil washing was conducted to treat the samples. Chemical agents, such as acetic acid, ethylenediaminetetra acetic acid (EDTA) and hydrochloric acid, were used as washing solutions to remove chromium and cadmium from sludge samples. The results of this study indicated that the highest removal efficiencies from the sludge samples were achieved using a 0.3 M HCl solution with 82.69% and 74.47% for chromium and cadmium, respectively. EDTA (0.1 M) in the best condition extracted 66.81% of cadmium and 72.52% of chromium from the sludges. The lowest efficiency values for the samples, however, were achieved using 3 M acetic acid with 41.7% and 46.96% removals for cadmium and chromium, respectively. The analysis of washed sludge indicated that the heavy metals removal decreased in the order of 3 M acetic acid < 0.1 M EDTA<0.3 M HCl, thus hydrochloric acid appears to offer a greater potential as a washing agent in remediating the sludge samples.