402-55-1Relevant articles and documents
Effects of 18F-fluorinated neopentyl glycol side-chain on the biological characteristics of stilbene amyloid-β PET ligands
Tago, Tetsuro,Toyohara, Jun,Fujimaki, Ryo,Tatsuta, Maho,Song, Ruichong,Hirano, Keiichi,Iwai, Kumiko,Tanaka, Hiroshi
, p. 38 - 45 (2021/01/26)
Introduction: The 2,2-dihydroxymethyl-1-[18F]fluoropropane group, also called 18F-labelled neopentyl glycol side-chain, is a novel 18F-labelling group for positron emission tomography (PET) imaging agents. The aim of using this group is to develop simple purification with solid-phase extraction without high-performance liquid chromatography. However, the effects of the neopentyl 18F-labelling group on the characteristics of brain imaging agents are unknown. Here, we added this side-chain to compounds with an aminostilbene structure to evaluate their effects on the biological properties of aminostilbene as an amyloid-β (Aβ) radioligand. Methods: Biodistributions of four novel 18F-labelled stilbene compounds with different lengths of polyethylene glycol (PEG) linkers, called [18F]Cpd-0, -1, -2, and -4, (PEG = 0, 1, 2, and 4), and [18F]AV-1 in normal mice were evaluated. Metabolite analysis of [18F]Cpd-0 and -1 was performed with mouse plasma and brain. A competitive binding assay of [18F]AV-1 binding to Aβ1–42 fibrils was performed to determine the binding properties of the compounds. Results: [18F]Cpd-0, -1, and -2 demonstrated moderate initial brain uptake in mice (3.1–4.2% injected dose/g at 2 min post-injection) followed by fast clearance, and in vivo defluorination of these compounds was negligible. [18F]Cpd-4 exhibited low brain uptake and high bone uptake. Compared with [18F]Cpd-1, the percentage of [18F]Cpd-0 in mouse brain was high at 10 min post-injection. A competitive binding assay revealed partial interference effects by the neopentyl glycol side-chain on binding of stilbene compounds to Aβ1–42 fibrils. Conclusions: Aminostilbene compounds with two or fewer PEG linkers containing an 18F-labelled neopentyl glycol side-chain demonstrated preferable pharmacokinetic properties as a brain imaging radioligand in normal mice. These side-chains can be used as an alternative labelling group for imaging agents targeting the brain.
Development of Covalent Ligands for G Protein-Coupled Receptors: A Case for the Human Adenosine A3 Receptor
Yang, Xue,Van Veldhoven, Jacobus P. D.,Offringa, Jelle,Kuiper, Boaz J.,Lenselink, Eelke B.,Heitman, Laura H.,Van Der Es, Daan,Ijzerman, Adriaan P.
, p. 3539 - 3552 (2019/04/16)
The development of covalent ligands for G protein-coupled receptors (GPCRs) is not a trivial process. Here, we report a streamlined workflow thereto from synthesis to validation, exemplified by the discovery of a covalent antagonist for the human adenosine A3 receptor (hA3AR). Based on the 1H,3H-pyrido[2,1-f]purine-2,4-dione scaffold, a series of ligands bearing a fluorosulfonyl warhead and a varying linker was synthesized. This series was subjected to an affinity screen, revealing compound 17b as the most potent antagonist. In addition, a nonreactive methylsulfonyl derivative 19 was developed as a reversible control compound. A series of assays, comprising time-dependent affinity determination, washout experiments, and [35S]GTPγS binding assays, then validated 17b as the covalent antagonist. A combined in silico hA3AR-homology model and site-directed mutagenesis study was performed to demonstrate that amino acid residue Y2657.36 was the unique anchor point of the covalent interaction. This workflow might be applied to other GPCRs to guide the discovery of covalent ligands.
Irreversible Cysteine-Selective Protein Labeling Employing Modular Electrophilic Tetrafluoroethylation Reagents
Václavík, Ji?í,Zschoche, Reinhard,Klimánková, Iveta,Matou?ek, Václav,Beier, Petr,Hilvert, Donald,Togni, Antonio
supporting information, p. 6490 - 6494 (2017/05/15)
Fluoroalkylation reagents based on hypervalent iodine are widely used to transfer fluoroalkyl moieties to various nucleophiles. However, the transferred groups have so far been limited to simple structural motifs. We herein report a reagent featuring a secondary amine that can be converted to amide, sulfonamide, and tertiary amine derivatives in one step. The resulting reagents bear manifold functional groups, many of which would not be compatible with the original synthetic pathway. Exploiting this structural versatility and the known high reactivity toward thiols, the new-generation reagents were used in bioconjugation with an artificial retro-aldolase, containing an exposed cysteine and a reactive catalytic lysine. Whereas commercial reagents based on maleimide and iodoacetamide labeled both sites, the iodanes exclusively modified the cysteine residue. The study thus demonstrates that modular fluoroalkylation reagents can be used as tools for cysteine-selective bioconjugation.
