7458-03-9Relevant articles and documents
Magnetoluminescent agents for dual MRI and time-gated fluorescence imaging
Smolensky, Eric D.,Zhou, Yue,Pierre, Valerie C.
, p. 2141 - 2147 (2012)
The synthesis and properties of two luminescent iron oxide nanoparticles for dual imaging by MRI and time-gated confocal microscopy are presented. These magnetoplasmonic agents consist of macrocyclic terbium complexes conjugated onto magnetite nanoparticles by a polyethylene glycol linker. Two macrocyclic terbium complexes were investigated: Tb-DOTAm-(Phen)3 and Tb-DOTAm-(acetylene)3. Both complexes display the characteristic long luminescence lifetimes of lanthanides (0.8 ms and 1.3 ms, respectively), rendering them ideal for time-gated luminescence spectroscopy and confocal imaging - a feature currently unexplored in multimodal imaging agents. Additionally, the 5 ± 1 nm magnetite nanoparticles, with their permeable PEG coating and stable dopamide anchor, render the two constructs efficient MRI contrast agents with longitudinal (r1) and transverse (r2) relaxivities of 9.8 mM-1Fe s-1 and 98 mM -1Fe s-1 at 60 MHz and 37 °C. The synthesis and characterization of Fe3O4@Tb-DOTAm-(acetylene) 3 and Fe3O4@Tb-DOTAm-(Phen)3, two magnetoluminescent agents for dual imaging by MRI and confocal imaging are presented. The nanoparticles are characterized by high transverse and longitudinal relaxivities and long luminescence lifetimes ideal for time-gated spectroscopy. Copyright
Direct Peptide Cyclization and One-Pot Modification Using the MeDbz Linker
Gless, Bengt H.,Olsen, Christian A.
, p. 10525 - 10534 (2018/09/06)
The one-pot synthesis and modification of cyclic peptides through a self-cleaving on-resin protocol is described. We apply Dawson's MeDbz linker to achieve direct intramolecular peptide cyclization by thioesterification followed by S → N acyl shift. This native chemical ligation approach requires no activating additive and allows direct modification of the crude cyclic peptides in one-pot. The strategy was applied to synthesize 5 cyclic peptide natural products of varying ring size. Finally, one-pot modifications include desulfurization, fluorophore conjugation, and intramolecular disulfide formation.
Optimizing the readout of lanthanide-DOTA complexes for the detection of ligand-bound copper(I)
Hanna, Jill R.,Allan, Christopher,Lawrence, Charlotte,Meyer, Odile,Wilson, Neil D.,Hulme, Alison N.
supporting information, (2017/06/08)
The CuAAC 'click' reaction was used to couple alkyne-functionalized lanthanide-DOTA complexes to a range of fluorescent antennae. Screening of the antenna components was aided by comparison of the luminescent output of the resultant sensors using data normalized to account for reaction conversion as assessed by IR. A maximum 82-fold enhanced signal:background luminescence output was achieved using a Eu(III)-DOTA complex coupled to a coumarin-azide, in a reaction which is specific to the presence of copper(I). This optimized complex provides a new lead design for lanthanide-DOTA complexes which can act as irreversible 'turn-on' catalytic sensors for the detection of ligand-bound copper(I).
