scholarly journals Generation of Pseudocontact Shifts in Proteins with Lanthanides Using Small “Clickable” Nitrilotriacetic Acid and Iminodiacetic Acid Tags

2015 ◽  
Vol 21 (13) ◽  
pp. 5084-5092 ◽  
Author(s):  
Choy-Theng Loh ◽  
Bim Graham ◽  
Elwy H. Abdelkader ◽  
Kellie L. Tuck ◽  
Gottfried Otting
Keyword(s):  
Iminodiacetic Acid ◽  
Nitrilotriacetic Acid ◽  
Pseudocontact Shifts

Oxidation of CrIII aminocarboxylate complexes by hydrous manganese oxide: products and time course behaviour

2015 ◽  
Vol 12 (1) ◽  
pp. 33 ◽  
Author(s):  
Richard F. Carbonaro ◽  
Alan T. Stone
Keyword(s):  
Manganese Oxide ◽  
Time Course ◽  
Ethylenediaminetetraacetic Acid ◽  
Environmental Concern ◽  
Iminodiacetic Acid ◽  
Nitrilotriacetic Acid ◽  
Product Distribution ◽  
Hydrous Manganese Oxide ◽  
Wide Ph Range ◽  
Ph Range

Environmental context Oxidation of CrIII (trivalent chromium) to CrVI (hexavalent chromium) is of environmental concern because CrVI is a known mutagen and carcinogen. Our results show that hydrous manganese oxide (HMO) is capable of oxidising soluble CrIII complexed with iminodiacetic acid and nitrilotriacetic acid to CrVI at appreciable rates. CrVI production from soluble CrIII organic complexes is therefore expected to occur in natural and engineered systems that contain HMO. Abstract MnIII,IV (hydr)oxides are believed to be the principal oxidants of CrIII in the subsurface. In nearly all previous work on this subject, the CrIII reactant was prepared from inorganic salts (e.g. nitrate, chloride, sulfate). In our present work, CrIII complexes with the synthetic chelating agents iminodiacetic acid (IDA) and nitrilotriacetic acid (NTA) were reacted with hydrous manganese oxide (HMO) over a wide pH range to examine rates of reaction and product distribution. Capillary electrophoresis was used to quantify changes in reactant (CrIII–IDA and CrIII–NTA) and product (CrVI, free IDA and free NTA) concentrations as a function of time. In addition, a small number of experiments were performed using solutions prepared from CrIII alum (KCr(SO4)2·12H2O(s)) as the CrIII reactant. CrIII–IDA and CrIII–NTA were oxidised to CrVI, but rates were considerably lower than those obtained using inorganic CrIII. Within the timescales of our experiments, complete conversion of CrIII–NTA occurred at pH >7, but not under moderately acidic conditions, even when there was a large stoichiometric excess of HMO. MnCl2 addition experiments indicated that the observed reaction inhibition was attributable to MnII generation during the reaction. Our previous work has shown that citric acid, IDA, NTA and ethylenediaminetetraacetic acid solubilise CrIII from amorphous Cr(OH)3(s) at appreciable rates. The results of this study show that HMO is capable of oxidising the resulting soluble CrIII complexes, providing a viable mechanism for CrIII oxidation to CrVI over a wide pH range.

Gel self-assembly of lanthanum aminopolycarboxylates with skeleton structures and adsorptions of gases

2021 ◽  
Author(s):  
Si-Yuan Wang ◽  
Zhenlang Xie ◽  
Xin Dong ◽  
Zhao-Hui Zhou
Keyword(s):  
Self Assembly ◽  
Ethylenediaminetetraacetic Acid ◽  
Iminodiacetic Acid ◽  
Nitrilotriacetic Acid ◽  
Edta Ethylenediaminetetraacetic Acid

Three lanthanum aminopolycarboxylates [La(Hida)2(H2O)2]n·nCl·4nH2O (1), K2n[La(nta)2]n·nH2O (2) and (H2en)n[La(edta)(H2O)]2n·10nH2O (3) (H2ida = iminodiacetic acid; H3nta = nitrilotriacetic acid; H4edta = ethylenediaminetetraacetic acid; en = ethylenediamine, NH2CH2CH2NH2) have been isolated by...

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