Effect of the structure of 16-membered tetraaza macrocyclic ligands on the rate of substitution of zinc ions by copper ions in their complexes

1983 ◽  
Vol 18 (5) ◽  
pp. 575-579
Author(s):  
K. B. Yatsimirskii ◽  
V. V. Pavlishchuk
2021 ◽  
Vol 13 (8) ◽  
pp. 4184
Author(s):  
Zhiying Xu ◽  
Caterina Valeo ◽  
Angus Chu ◽  
Yao Zhao

This research investigates the use of a common food waste product for removing four different types of metals typically found in stormwater. Whole, unprocessed oyster shells are explored for use in stormwater management infrastructure that addresses water quality concerns. The role of the shells’ surface area, exposure time, and the solution’s initial concentration on the removal efficiency were examined. Beaker scale experimental results demonstrated very good efficiency by the oyster shells for removing copper ions (80–95%), cadmium ions (50–90%), and zinc ions (30–80%) but the shells were not as effective in removing hexavalent chromium (20–60%). There was a positive relationship between initial concentration and removal efficiency for copper and zinc ions, a negative relationship for hexavalent chromium, and no relationship was found for cadmium ions. There was also a positive relationship between surface area and removal efficiency, and exposure time and removal efficiency. However, after a certain exposure time, the increase in removal efficiency was negligible and desorption was occasionally observed. A mid-scale experiment to mimic real-world conditions was conducted in which continuous inflow based on a 6-h design storm was applied to 2.7 kg of whole, unprocessed oyster shells. The shells provided an 86% and an 84% removal efficiency of cadmium and copper ions, respectively, in one day of hydraulic retention time. No removal was observed for hexavalent chromium, and zinc ion removal was only observed after initial leaching. This work has significant implications for sustainable stormwater infrastructure design using a material commonly found in municipal food waste.


2002 ◽  
Vol 21 (8) ◽  
pp. 421-427 ◽  
Author(s):  
P W Smet ◽  
T F Pauwels ◽  
P J Dierickx

The effect of macrocyclic ligands on cytotoxic concentrations of the transition metal ions of copper, zinc, and cadmium was investigated. For this purpose, a hexaaza-[3,6,9,17,20,23-hexaazatricyclo[23.3.1.111,15] triaconta–1(29),11(30),12,14,25,27–hexaene (L2)] and hexathia-chelating ligand [1,4,7,10,13,16-hexathiacyclooctadecane (L3)] were used in the human hepatoma-derived HepG2 cell line. The cytotoxicity was measured by the neutral red uptake inhibition assay. First, the NI50 of the ligands, i.e., the concentration of the ligand inducing a 50% inhibition in neutral red uptake compared to control cells, was determined. In several metal/ligand combination experiments, the effects for L2 were difficult to interpret, whereas for L3 in combination with copper ions, a severe increase–and for zinc ions, a significant decrease of cell toxicity–relative to the metal control was observed. To further examine the different effects observed with L3 in combination with, respectively, Cu2+ and Zn2+, the glutathione (GSH) content was measured. The relative GSH content decreased as the concentration of L3 increased. It was proposed that the increased toxicity of the combination Cu2+ /L3 could be caused by the depletion of GSH and a subsequent inability to scavenge the produced reactive oxygen species (ROS). This hypothesis was supported by experiments during which vitamin E or C was added to the Cu2+ / L3 system.


1985 ◽  
Vol 21 (2) ◽  
pp. 168-174
Author(s):  
K. B. Yatsimirskii ◽  
V. V. Pavlishchuk ◽  
E. V. Rybak-Akimova

2014 ◽  
Vol 661 ◽  
pp. 39-44
Author(s):  
Nur Khalida Adibah Md Rodzi ◽  
Senusi Faraziehan ◽  
Alrozi Rasyidah

In this study, biosorption of copper and zinc ions on Baker’s yeast, Saccharomyces Cerevisiae was investigated. The data of batch experiments was used to perform equilibrium and kinetic studies. The experimental results were fitted well to the Langmuir and Freundlich model isotherms. According to the parameters of Langmuir isotherm, the maximum biosorption capacities of copper and zinc ions onto immobilized yeast were 5.408mg/g and 1.479mg/g at 293 Kfor the treated beads. Competitive biosorption of two metal ions was investigated in terms of maximum sorption quantity. The binding capacity for copper ions is more than the zinc ions for both untreated and treated immobilized yeast.While, for the kinetic studies, the pseudo second order model was found the most suitable model for the present systems.


Author(s):  
S. B. Cheknev ◽  
E. I. Vostrova ◽  
M. A. Sarycheva ◽  
A. V. Vostrov

Aim. The work was performed with the purpose to study a hemolytic activity in the culture of S.pyogenes under the inhibitory action of millimolar concentrations of zinc ions.Materials and methods. Suspensions of S.pyogenes bacteria which contained 108 CFU/ml were sown by the lawns into the standard Petri dishes coated with the supplemented Blood Nutrient Agar. 30 min later the salt solutions of zinc or copper which contained the metals at the concentrations ranged between 5 x 10-3 M to 5 x 10-1 M were added by the 5 μl drops on the surfaces of the lawns with use of 36-channel stamp replicator. Then the dishes with bacterial cultures were incubated for 24 hrs at 37°C followed by measuring diameter of the area of culture growth inhibition and of the area of inhibition of hemolysis. The study was performed with use of controls towards measuring the state of bacterial cells obtained from different zones of the areas.Results. In presence of the zinc ions concentrations ranged between 50 to 500 mM the area of the growth inhibition of S.pyogenes was surrounded on the lawn of the bacterial culture by the area of the inhibition of hemolysis where the growth inhibition of S.pyogenes was not registered. Copper ions did not form such an area of the hemolysis inhibition.Conclusion. Inhibitory action of zinc ions on the hemolytic S.pyogenes activity in the culture seems to be specific and reversible, and is discussed in a context of the antivirulent zinc ions properties.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3600
Author(s):  
Chise Nagao ◽  
Kunisato Kuroi ◽  
Taiyu Wakabayashi ◽  
Takakazu Nakabayashi

Cu, Zn superoxide dismutase (SOD1) is a representative antioxidant enzyme that catalyzes dismutation of reactive oxygen species in cells. However, (E,E)-SOD1 mutants in which both copper and zinc ions were deleted exhibit pro-oxidant activity, contrary to their antioxidant nature, at physiological temperatures, following denaturation and subsequent recombination of Cu2+. This oxidative property is likely related to the pathogenesis of amyotrophic lateral sclerosis (ALS); however, the mechanism by which Cu2+ re-binds to the denatured (E,E)-SOD1 has not been elucidated, since the concentration of free copper ions in cells is almost zero. In this study, we prepared the (Cu,E) form in which only a zinc ion was deleted using ALS-linked mutant H43R (His43→Arg) and found that (Cu,E)-H43R showed an increase in the pro-oxidant activity even at physiological temperature. The increase in the pro-oxidant activity of (Cu,E)-H43R was also observed in solution mimicking intracellular environment and at high temperature. These results suggest that the zinc-deficient (Cu,E) form can contribute to oxidative stress in cells, and that the formation of (E,E)-SOD1 together with the subsequent Cu2+ rebinding is not necessary for the acquisition of the pro-oxidant activity.


2020 ◽  
Vol 27 (36) ◽  
pp. 45992-46002
Author(s):  
Jingting He ◽  
Shuaining Ma ◽  
Ling Liu ◽  
Chang Liu ◽  
Shaojun Dong

1977 ◽  
Vol 23 (8) ◽  
pp. 1002-1010 ◽  
Author(s):  
D. M. Halsall

The effects of copper, boron, cobalt, manganese, molybdenum, and zinc on the production of zoosporangia by P. cinnamomi and P. drechsleri in the presence of favourable concentrations of calcium, magnesium, potassium, and iron were investigated. Copper ions were the most effective in reducing the numbers of zoosporangia formed by both fungal species. Molybdenum was also slightly inhibitory.Total inhibition of mycelial growth occurred between 1 and 5 × 10−5 M Cu2+ whereas total inhibition of sporangial formation occurred between 1 and5 × 10−7 M Cu2+. At copper concentrations between 10−5 M and 5 × 10−7 M, many P. drechsleri zoosporangia were abnormal in appearance and nonviable.Infection of eucalypt cotyledons by P. drechsleri zoospores was inhibited by 10−6 M Cu2+ but this inhibition was reversed by EDTA (10−4 M). There was no evidence for interaction between Cu2+ and Ca2+, Mg2+, K+, or Fe2+ present in the solutions used in the axenic production of zoospores. Preliminary pot trials indicated that CuSO4 had a protective action for safflower seedlings to infection by P. drechsleri when CuSO4 was applied as a dilute solution over the infection period.


2015 ◽  
Vol 1 (12) ◽  
Author(s):  
Alexandra Bekényiová ◽  
Iveta Štyriaková ◽  
Zuzana Danková

In the present work, the abilities of natural and synthetic samples of goethite and hematite to remove copper Cu(II) ) and zinc Zn(II) ions from aqueous solutions were compared. Batch adsorption experiments were performed in order to evaluate the removal efficiency of iron oxide samples. The effect of initial metal ion concentration, initial pH and time on adsorption of copper and zinc onto the iron oxides has been studied. The sorption data were represented by the linearized Langmuir model. Comparing the values of adsorption capacities, there were differences between the natural and synthetic samples, natural and synthetic goethite had higher sorption capacity for both metals than hematite. The copper ions showed higher affinity than zinc ions to all samples.


Author(s):  
O. Ye. Kopach ◽  
N. A. Fedoriv ◽  
N. A. Melnyk ◽  
H. A. Krytska

Skeletal trauma causes significant biliary tract violations of the liver. Excess copper ions and zinc reduces biliary function of the liver. The aim of the study – to find out the pathogenetic features of liver damage in the case of mechanical injury of varying severity in the presence of excess copper and zinc ions in the body and its antidote therapy. Material and Methods. Experiments were performed on 150 non-linear white male rats weighing 180–200 g. In the context of chronic intoxication with copper and zinc sulfates, they simulated skeletal trauma of varying severity. In animals after 1, 3 and 7 days of post-traumatic period, bile duct function of the liver was studied. The received digital data was subject to statistical analysis. Results and Discussion. Against the background of a medium-degree injury, the indicator varied wavy: after 1 day it increased significantly in relation to the control group (by 32.7 %, p<0.05). After 3 days it significantly decreased and became 17.6 % less than control (p<0.05). After 7 days, it continued to remain at the same level (p<0.05 for control). In conditions of excessive ion exchange of copper and zinc in 1 day the indicator was at the control group level (p>0.05). However, after 3 and 7 days it was significantly lower than the reference level (27.8 % and 24.3 % respectively, p<0.05). In these conditions, after 1 and 3 days, the indicator was statistically significantly lower on the background of excessive intake of copper and zinc ions (31.6 % and 12.4 % respectively, p<0.05). Conclusions. Skeletal trauma causes a significant violation of biliary tract function of the liver. At a trauma of a light degree without intoxication copper and zinc salts in 1 day the index to 7 days increases. While in the middle and severe injuries, after 1 day it is greater than control, but in the future it is lower than the control group. Excessive intake of copper ions and zinc contributes to a decrease in the studied index from 1 to 7 days, and with the trauma of moderate and severe severity of the lungs 3 and 7 days it becomes significantly lower than in the nontoxic group.


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