- Effective Na+-Binding Ability and Molecular Assembly of an Alkylamide-Substituted Penta(ethylene)glycol Derivative
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A new amphiphilic penta(ethylene glycol) derivative (1) bearing two hydrogen-bonding -CONHC14H29 chains was prepared. Compound 1 exhibited ion-recognition abilities for Na+ and K+, and its properties were compared with those of the macrocyclic [18]crown-6. Although both compound 1 and [18]crown-6 have six ether oxygen atoms (-OC2H2-), the Na+-binding ability of the former was much higher than that of the latter. K+-binding ability of cyclic [18]crown-6 was much higher than its Na+-binding ability, while the reverse was true for acyclic compound 1. Single-crystal X-ray structural analysis of Na+·1·B(Ph)4-·(hexane)2 at 100 K revealed the existence of a wrapped Na+-coordination by six ether and one carbonyl oxygen atoms of 1, which was further stabilized by intramolecular N-H···O= hydrogen-bonding interactions. The complex phase transition during glass (G) formation and recrystallization was confirmed in the thermal cycle of Na+·1·B(Ph)4-, whose molten state showed two kinds of liquid phases, Na+-complexed (Na+·1) + B(Ph)4- and completely dissociated Na+ + 1 + B(Ph)4-. The Na+ conductivity of the molten state was 2 orders of magnitude higher than that of the G phase.
- Seto, Shinya,Takeda, Takashi,Hoshino, Norihisa,Akutagawa, Tomoyuki
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p. 6349 - 6358
(2021/06/28)
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- Homo-PROTACs: Bivalent small-molecule dimerizers of the VHL E3 ubiquitin ligase to induce self-degradation
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E3 ubiquitin ligases are key enzymes within the ubiquitin proteasome system which catalyze the ubiquitination of proteins, targeting them for proteasomal degradation. E3 ligases are gaining importance as targets to small molecules, both for direct inhibition and to be hijacked to induce the degradation of non-native neo-substrates using bivalent compounds known as PROTACs (for 'proteolysis-targeting chimeras'). We describe Homo-PROTACs as an approach to dimerize an E3 ligase to trigger its suicide-type chemical knockdown inside cells. We provide proof-of-concept of Homo-PROTACs using diverse molecules composed of two instances of a ligand for the von Hippel-Lindau (VHL) E3 ligase. The most active compound, CM11, dimerizes VHL with high avidity in vitro and induces potent, rapid and proteasome-dependent self-degradation of VHL in different cell lines, in a highly isoform-selective fashion and without triggering a hypoxic response. This approach offers a novel chemical probe for selective VHL knockdown, and demonstrates the potential for a new modality of chemical intervention on E3 ligases.
- Maniaci, Chiara,Hughes, Scott J.,Testa, Andrea,Chen, Wenzhang,Lamont, Douglas J.,Rocha, Sonia,Alessi, Dario R.,Romeo, Roberto,Ciulli, Alessio
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- ALBUMIN-BINDING COMPOUNDS
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The present invention provides an albumin-binding compound essentially of the following elements: a spacer group, a water-soluble bridging group, a fatty acid chain and an acidic group characterised in that the acidic group is attached to the distal end of the fatty acid chain. The invention also provides an albumin-binding compound to which one or more biologically active moieties are attached.
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Page/Page column 24-25
(2010/02/15)
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- Ligand Recognition by E- and P-Selectin: Chemoenzymatic Synthesis and Inhibitory Activity of Bivalent Sialyl Lewis x Derivatives and Sialyl Lewis x Carboxylic Acids
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Described is the preparation of five sLex dimers and five sLex carboxylic acids by coupling chemoenzymatically synthesized amino-substituted sialyl Lewis x (sLex) derivative 4 to homobifunctional cross-linkers 20-24 of varying chain length. 20-24 were obtained by alkylating low-molecular-weight oligoethylene glycols with tert-butyl bromoacetate and subsequent transformation of the di-tert-butyl esters into disuccinimide esters. The products were assayed for inhibition against binding of a sLea-polymer to immobilized E- and P-selectin. In the E-selectin assay all dimers had lower IC50 values than the sLex monomer. The results show that comparable binding enhancements can be obtained with linkers of completely different length and rigidity. In the P-selectin assay four of the five sLex carboxylic acids displayed significantly improved inhibitory potency. The lowest IC50 value was observed for the compound with the shortest spacer between the sLex moiety and the additional carboxylate, being ca. 20-40 times more potent than unmodified sLex. These findings should be of importance for the design of new multivalent forms of sLex as well as sLex mimetics as high-affinity selectin ligands.
- Wittmann, Valentin,Takayama, Shuichi,Gong, Ke Wei,Weitz-Schmidt, Gabriele,Wong, Chi-Huey
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p. 5137 - 5143
(2007/10/03)
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