title: Preparation and study of new poly-8-hydroxyquinoline chelators for an anti-Alzheimer strategy.
abstract: Fourteen different ligands have been synthesized with two covalently linked 8-hydroxyquinoline motifs that favor metal complexation. These bis-chelators include different bridges at the C2 positions and different substituents to modulate their physicochemical properties. They can form metal complexes in a ratio of one ligand per metal ion with Cu II and Zn II, two metal ions involved in the formation of amyloid aggregates of the toxic Abeta-peptides in the Alzheimer disease. The apparent affinity of all bis-8-hydroxyquinoline ligands for Cu II and Zn II are similar with logK Cu II approximately 16 and logK Zn II approximately 13 and are 10,000 times more efficient than for the corresponding 8-hydroxyquinoline monomers. Their strong chelating capacities allow them to inhibit more efficiently than the corresponding monomers the precipitation of Abeta-peptides induced by Cu II and Zn II and also to inhibit the toxic formation of H2O2 due to copper complexes of Abeta. The best results were obtained with a one-atom linker between the two quinoline units. X-ray analyses of single-crystals of Cu II, Zn II or Ni II complexes of 2,2'-(2,2-propanediyl)-bis(8-hydroxyquinoline), including a one-atom linker, showed that all heteroatoms of the bis-8-hydroxyquinoline ligand chelate the same metal ion in a distorted square-planar geometry. The Cu II and Zn II complexes include a fifth axial ligand and are pentacoordinated.
authors.affiliation: Laboratoire de Chimie de Coordination du CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Deraeve
authors.forename: Christophe
authors.initials: C
authors.lastname: Boldron
authors.forename: Alexandrine
authors.initials: A
authors.lastname: Maraval
authors.forename: Honoré
authors.initials: H
authors.lastname: Mazarguil
authors.forename: Heinz
authors.initials: H
authors.lastname: Gornitzka
authors.forename: Laure
authors.initials: L
authors.lastname: Vendier
authors.forename: Marguerite
authors.initials: M
authors.lastname: Pitié
authors.forename: Bernard
authors.initials: B
authors.lastname: Meunier
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000187:drug effects; D002614:Chelating Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D006861:Hydrogen Peroxide / Q000037:antagonists & inhibitors / Q000138:chemical synthesis / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D015125:Oxyquinoline / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry / Q000187:drug effects; D011108:Polymers / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
chemical_list: D016229:Amyloid beta-Peptides; D002614:Chelating Agents; D008024:Ligands; D009942:Organometallic Compounds; D010446:Peptide Fragments; D011108:Polymers; C075222:amyloid beta-protein (1-42); D015125:Oxyquinoline; D003300:Copper; D009532:Nickel; D006861:Hydrogen Peroxide; D015032:Zinc