17018-82-5Relevant articles and documents
Cyclen-based chelators for the inhibition of Aβ aggregation: Synthesis, anti-oxidant and aggregation evaluation
Safadi, Mahmoud El,Bhadbhade, Mohan,Shimmon, Ronald,Baker, Anthony T.,McDonagh, Andrew M.
, p. 343 - 350 (2017)
The aggregation of the protein amyloid-β in the brain has been associated with neurodegenerative diseases such as Alzheimer's disease. Such aggregation of amyloid-β can be induced by misregulated metal ions such as Cu2+ and Zn2+. Here we present four metal chelating compounds based on the cyclen macrocycle that each bear a pendant arm to provide additional anti-oxidant activity. The corresponding Cu2+, Zn2+ and Ni2+ complexes have been synthesized and characterized to examine the ability of the chelators to bind to the metal centres. Aβ40 de-aggregation by the cyclen compounds was assessed using turbidometry and the re-solubilization of the Aβ40 was also examined. Our results show that the cyclen compounds have the ability to effectively chelate Cu2+ and Zn2+ metal ions and thus de-aggregate Aβ40 that has been aggregated due to the presence of these ions. The antioxidant properties of the cyclen compounds were tested by using the DPPH scavenging assay and the results show that some of the compounds can decrease oxidative stress.
Preparation of 2-substituted 8-quinolinols containing C, N, O-donor atoms and its PdII or PtII complexes
Yoneda, Akio,Newkome, George R.,Theriot, Kevin J.
, p. 217 - 226 (1991)
2-Substituted 8-quinolinols possessing two- (4) or three- (6) carbon side chains have been prepared from 2-formyl-8-quinolinol.A carbanion, generated on the side chain, serves as the C-donor of the bonding triad.The complexation with PdII or PtII salts in the presence of pyridine, as an external ligand, afforded the desired neutral chelates having M-C ?-bond as well as the 2 : 1 ML2 complex, possessing the intact methine proton.In the case of 6c possessing a pendant acetylacetonyl moiety, the 1H NMR spectrum suggested a predominance of the enol form, and uponcomplexation, the 2 : 1 ML2 complex was formed.Since these new ligands have three different hetero donor atoms, a novel palladium complex containing four different (C, N, O, P) coordinating sites, by the use of tri(n-butyl)phosphine as an external ligand, was prepared.
Metal ion size profoundly affects H3glyox chelate chemistry
Choudhary, Neha,Barrett, Kendall E.,Kubeil, Manja,Radchenko, Valery,Engle, Jonathan W.,Stephan, Holger,De Guadalupe Jaraquemada-Peláez, María,Orvig, Chris
, p. 15663 - 15674 (2021)
The bisoxine hexadentate chelating ligand, H3glyox was investigated for its affinity for Mn2+, Cu2+ and Lu3+ ions; all three metal ions are relevant with applications in nuclear medicine and medicinal inorganic chemistry. The aqueous coordination chemistry and thermodynamic stability of all three metal complexes were thoroughly investigated by detailed DFT structure calculations and stability constant determination, by employing UV in-batch spectrophotometric titrations, giving pM values (pM = -log[Mn+]free when [Mn+] = 1 μM, [L] = 10 μM at pH 7.4 and 25 °C)-pCu (25.2) > pLu (18.1) > pMn (12.0). DFT calculated structures revealed different geometries and coordination preferences of the three metal ions; notable was an inner sphere water molecule in the Mn2+ complex. H3glyox labels [52gMn]Mn2+, [64Cu]Cu2+ and [177Lu]Lu3+ at ambient conditions with apparent molar activities of 40 MBq μmol-1, 500 MBq μmol-1 and 25 GBq μmol-1, respectively. Collectively, these initial investigations provide insight into the effects of metal ion size and charge on the chelation with the hexadentate H3glyox and indicate that further investigations of the Mn2+-H3glyox complex in 52g/55Mn-based bimodal imaging might be worthwhile.
