• Journal of Applied Biological Chemistry
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• v.49 no.1
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• pp.8-10
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• 2006

Compositions of methionine-metal chelates have been investigated by FT-IR and XRD studies to elucidate their molecular structures. It was concluded that Copamin and Zincamin contain a high percentage of crystalline products, presumably 2:1 Methionine-Cu or Zn complexes. On the contrary, FT-IR and XRD spectra of Ferramin didn't show any characteristics of the chelate and it was concluded to contain major components of starting $FeSO_4$ and methionine without chelation.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.2
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• pp.77-87
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• 2009

Purpose : To evaluate the effects of Samultang(SMT) on the metals in the dams and fetuses Method : SMT(Decoction) was administered orally using different concentrations to pregnant Sprague-Dawley rats for 20days after being assigned randomly to 5 groups. Each group has 11 dams. Pregnant rats were sacrificed at the 20th day of gestation and metal concentration in the dams and fetuses was observed using a ICP-MS and mercury analyzer. Results : Hg concentration in the blood of dams was lower in the $SMT{\times}1$, $SMT{\times}2$, $SMT{\times}4$group than VC(Vehicle Control) and Control group. Hg concentration in the organs of dams was lower in the $SMT{\times}1$, $SMT{\times}2$, $SMT{\times}4$ group than VC, Control group. Whereas Cd concentration in the organs of fetuses was getting lower as increasing SMT dose, Hg concentration in the organs of fetuses was getting higher as increasing SMT dose. Discussion and Conclusion : There were not any significant harmful differences of metal concentration in the dams and fetuses treated by SMT. Particularly, SMT showed the possibility of efficacy to reduce the concentration of Hg in dams but to increase the concentration of Hg in fetuses. The mechanism of reduction is not yet proven. A hypothesis says there is a possibility of the chelation effect between the essential elements of herbs and heavy metals. Another hypothesis is the possibility of Hg transmission from dam to fetus. Further study should be conducted to make guidelines for the safe use of herbal medicine.

• Journal of the Korean Ceramic Society
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• v.31 no.7
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• pp.804-812
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• 1994

Stable PZT coating sol was prepared using chelating agent, ethylacetoacetate(EAcAc) by sol-gel processing under ambient atmosphere. Through FT-IR spectrum analysis on solution of each reaction step, formation of metal complex was confirmed and prepared PZT sol was stable over several months. Through TG-DTA, XRD, FT-IR spetrum analysis of PZT gel powder, it was understood that the addition of EAcAc could reduce the transition temperature to ferroelectric phase, due to the increased homogeneity by matching the hydrolysis and condensation rates by chelation. Single perovskite phase was obtained by the heat-treatment at 54$0^{\circ}C$ for 30 min. The film was coated on ITO-coated glass substrate by dip coating method. After heat-treatment, PZT thin film had thickness in the range of 20~130 nm. The maximum dielectric constant of its thin film at room temperature and 1 kHz was 128.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1429-1434
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• 2013

A synthesis and cation-induced fluorescent behavior of the carbazole-attached $NO_2S_2$-macrocycle (L) is described and structurally characterized by single crystal X-ray analysis. The photoluminescence spectrum of L in 80% $CH_3CN/CH_2Cl_2$ displays a peak maximum at 431 nm (blue emission). In the metal-induced fluorometric experiment, L showed a drastic chelation-enhanced fluorescence quenching (CHEQ) effect only with $Hg^{2+}$ and $Cu^{2+}$. In ESI-mass study, a 1:1 stoichiometry for complexation of L with $Hg^{2+}$ was confirmed, suggesting the unique sensing behavior of the proposed ligand L due to the selective complexation affinity for $Hg^{2+}$. The observed results indicate that L is a promising turn-off type fluoroionophore for $Hg^{2+}$ and $Cu^{2+}$ detections. Additionally, the $Ag^+$ complex of the precursor macrocycle was prepared and its solid structure was crystallographically characterized.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.115-122
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• 2016

Melanin is a common name used for a certain type of natural dark pigments existing in living organisms, particularly in human hair, eyes, and skin. The unique free radical scavenging effect of melanine could help protecting cells and tissues from harmful UV light. While their exact molecular structures in nature are not still well defined, their multifunctional properties including electrical and ionic conductivities, antioxidation, wet adhesion, and metal ion chelation, are highlighted for the potential applications in bioorganic electronics including biomedical sensors and devices. In this mini-review, we will discuss sources, synthesis methods, structures and multifunctional properties of melanin materials in addition to current research directions on a wide range of applications.

• Membrane Journal
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• v.26 no.4
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• pp.310-317
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• 2016

Lithium ion secondary battery (LISB) is an energy conversion system operated via charging-discharging cycle based on Lithium ion migration. LISB has a lot of advantages such as high energy density, low self-discharge rate, and a relatively high lifetime. Recently, increasing demands of electric vehicles have been encouraging the development of LISB with high capacity. Unfortunately, it causes some critical safety issues. It includes dendrite formation on negative electrode, resulting in electric shortage problems and battery explosion. Also, the elevated temperatures occurred during the LISB operation induces thermal shrinkage of polyolefin (e.g., polyethylene and polypropylene) separators. Consequently, the low thermal stability leads to decay of LISB performances and the reduction of lifetime. In this study, sulfonated poly (arylene ether sulfone) (SPAES) random copolymers were used as key materials to prepare polyolefin pore-filling separator. The resulting separators were evaluated in the term of metal ion chelation capability associated with dendrite formation, $Li^+$ ion conductivity and thermal durability.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.506-511
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• 2008

In this study sol-gel and combustion process was surveyed for the preparation of the red $Y_2O_3$: Eu phosphor, and the properties of phosphor was considered. Chelation and hydrolysis in amorphous citrate sol-gel process were completed in initial reaction stage, and water-forming condensation was superior to organic acid-forming condensation. The mole ratio of citric acid to metal ion had to be above to for the progress of sol-gel process. The dried gel powders are mostly amorphous, and crystallize completely at $700^{\circ}C$, and the crystallinity increases with increasing calcining temperature. The luminescence property of the phosphor was analyzed by measuring the emission spectra. The luminescence intensity increases when the calcination temperature and concentration of metal ions in solution increase.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.6
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• pp.402-409
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• 2001

Different bioligands carrying synthetic adsorbents have been reported in the literature for protein separation, We have developed a novel and new approach to obtain high protein ad-sorption capacity utilizing 2-methacrylamidohistidine(MAH) as a bioligand. MAH was synthe-sized by reacting methacrylocholride and histidine, Spherical beads with an average size of 150-200㎛ were obtained by the radical suspension polymerization of MAH and 2-hydrosyethyl-methacrylate(HEMA) conducted in an aqueous dispersion medium. p(HEMA-co-MAH) beads had a specific surface area of 17.6㎡/g . Synthesized MAH monomer was characterized by NMR. p(HEMA-co-MAH) beads were characterized by swelling test, FTIR and elemental analysis. Then Cu(II) ions were incorporated onto the beads and Cu(II) loading was found to be 0.96 mmol/g.These affinity beads with a swelling ration of 65% and containing, 1.6 mmol MAH/g were used in the adsorption/desorption of human serum albumin(HSA) from both aqueous solutions and hu-man serum. The adsorption of HSA onto p(HEM-co-MAH) was low(8.8 mg/g). Cu(II) chelation onto the beads significantly increased the HSA adsorption (56.3 mg/g). The maximum HSA ad-sorption ws observed at pH 8.0 Higher HSA adsorption was observed from human plasma(94.6 mgHSA/g) Adsorption of other serum proteins were obtained as 3.7 mg/g for fibrinogen and 8.5mg/g for γ-globulin. The total protein adsorption was determined as 107.1mg/g. Desorption of HSA was obtained using 0.1 M Tris/HCl buffer containing 0.5 M NaSCN, High desorption rations(up to 98% of the adsorbed HSA) were observed. It was possible to reuse Cu(II) chelated-p(HEMA-co-MAH) beads without significant decreases in the adsorption capacities.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.425-431
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• 1996

Human neutrophil elastases (HNElastase, EC 3.4.21.37), a causative factor of inflammatory diseases, are regulated by plasma proteinase inhibitors, alpha-proteinase inhibitor and ${\alpha}_2-macroglobulin$. Under certain pathological conditions, however, released enzymes or abnormal function of inhibitors may cause various inflammatory disease. NSAIDs have been clinically applied for treatment of inflammatory diseases. Inhibition of cyclooxygenase is a known mechanism of action of NSAIDs in the treatment of inflammatory disease. In in vitro experiments, HNElastase was inhibited by naproxen, phenylbutazone, and oxyphenbutazone, but ibuprofen, ketoprofen, aspirin, salicylic acid, and tolmetin did not inhibit elastase. HNElastase was also inhibited by chelating agents, EDTA & EGTA, and tetracyclines. Removal of divalent metal ions by EDTA caused inhibition of elastase, and reconstitution of the metal ions recovered the enzyme activity to a certain level. Frequencies and contours in the Raman spectra of various conditions of human neutrophil elastase undergo drastic changes upon partial removal and/or reconstitution of calcium and zinc ions. The metal ion content dependent activities and change of the contour of the Raman spectrogram suggest us that the mechanism of action of a chelator or chelator-like agents on neutrophil elastase may be related to the conformational change at/or near the active site, especially -C=O radical or -COOH radical.

• Ecology and Resilient Infrastructure
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• v.4 no.1
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• pp.63-70
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• 2017

Tetracycline (TC) groups, widely used veterinary antibiotics, can enter into environment through animal manure application. TC forms a ligand complex with multivalent metal cations via chelation that can affect sorption and mobility of TC in soil. So far, however, it has been confirmed through the reaction of the soil outside in the aqueous solution and the evaluation of the performance in the soil cultivation process is insufficient. The purpose of this study was to examine effects of copper on TC toxicity to lettuce growth. In this research, $750mg\;kg^{-1}$ of TC and 2.5, 7.5, $17.5mg\;kg^{-1}$ of Cu are treated in soil and lettuce was cultivated in the treated soil. Growth difference of lettuce by treatment was observed. As a result, $750mg\;kg^{-1}$ of TC treated soil showed toxic effect to lettuce and the effect is alleviated by copper treatment.