- Radical Reactions in Cavitands Unveil the Effects of Affinity on Dynamic Supramolecular Systems
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Radical reduction of alkyl halides and aerobic oxidation of alkyl aromatics are reported using water-soluble container compounds (1 and 2). The reductions involve α,ω-dihalides (4-8 and 10) with radical initiators in cavitand hosts with varied binding affinities. Product distributions lead to general guidelines for the use of dynamic supramolecular systems with fast reactions. The binding of guest substrates in the hosts must show high affinities (Ka> 103M-1) to ensure that the reactions take place under confinement in the containers.
- Angamuthu, Venkatachalam,Petroselli, Manuel,Rahman, Faiz-Ur,Rebek, Julius,Yu, Yang,Zhao, Xinluo
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supporting information
(2020/02/18)
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- BIVALENT BROMODOMAIN LIGANDS, AND METHODS OF USING SAME
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Described herein are compounds capable of modulating one or more biomolecules substantially simultaneously, e.g., modulating two or more binding domains (e.g., bromodomains) on a protein or on different proteins. For example, in one aspect, a bivalent compound or a pharmaceutically acceptable salt, stereoisomer, metabolite, or hydrate thereof is provided. In another aspect, a method of treating a disease associated with a protein having tandem bromodomains in a patient in need thereof is provided. The method comprises administering to the patient the bivalent compound as described.
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- Synthesis of both enantiomers of akolactone B and (+)-ancepsenolide
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The syntheses of (+)- and (-)-akolactone B and (+)-ancepsenolide were accomplished using a Pd-catalyzed carbonylation. As to the absolute configuration of akolactone B, making a comparison of the specific rotation of both enantiomers of synthetic akolactone B and the natural compound suggests that the absolute configuration at the 4-position of akolactone B is (R).
- Hikosaka, Gen,Hattori, Yasunao,Makabe, Hidefumi
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p. 1367 - 1371
(2014/12/11)
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- Conformationally restricted dynamic supramolecular catalysts for substrate-selective epoxidations
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A second generation of a substrate-selective dynamic supramolecular catalytic system consisting of a catalyst part and a receptor part, connected by a hydrogen-bonding motif, has been realized based on rational design. The results from analyses of the equilibrium mixture of the species generated by the components of the first generation system led us to selectively lock the cisoid conformation of the catalyst part to increase the amount of the substrate-selective catalytic cavity in the equilibrium mixture. This was realized by strapping the catalyst part by organic synthesis. This strapping led to an increase in substrate selectivity in the pair-wise competitive epoxidations of pyridyl- vs. phenyl-appended styrenes and pyridyl- vs. phenyl-appended stilbenes of both Z- and E- configuration compared to the first generation system, reaching 3.4:1 as the highest substrate selectivity for Z-mono-pyridyl-stilbene (27a) vs. the corresponding all-carbon analogue (28a) and for E-dipyridyl-stilbene (26b) vs. the corresponding all-carbon analogue (28b), respectively.
- Sheibani, Esmaeil,Waernmark, Kenneth
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experimental part
p. 2059 - 2067
(2012/04/23)
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- Quaternary bis-ammonium salt precursors and their uses as prodrugs having an antiparasitic activity
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The invention concerns drug precursors with antimalarial effect, characterised in that it consists in quaternary bis-ammonium salts of general formula (I) wherein A and A′, identical or different, are respectively either a group A1 and A′1 of formula (1)
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Page/Page column 17
(2010/02/14)
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- A new approach for the synthesis of [11C]-labeled fatty acids
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The synthesis of ω-[11C], ω-1-[11C] and ω-3-[11C] palmitic acid employing a cross-coupling reaction between a functionalized copper-zinc reagent with [11C]MeI, [1-11C]EtI and [1-11C]BuI is described. A tert.-butyl-protected ω-iodo fatty acid precursor (t)BuO2C-(CH2)(n)-I (n = 11, 13, 14) was converted into the corresponding dialkylzinc reagent [(t)BuO2C-(CH2)(n)]2Zn which reacts with Me2CuI(MgCl)2 to give a highly reactive copper reagent [(t)BuO2C-(CH2)(n)]2CuI(MgCl)2Me2Zn as the labeling precursor. The cross-coupling reaction with [11C]MeI, [1-11C]EtI and [1-11C]BuI provided the protected palmitic acid, specifically labeled with carbon-11 in several positions. The corresponding carbon-13 labeled compounds were synthesized to verify the labeling position. In a typical synthesis with [1-11C]EtI starting with 250 mCi of [11C]CO2, 14 mCi (6% decay-corrected based on [11C]CO2) of ω-1-[11C]palmitic acid was obtained within 30 minutes after EOB in 88% radiochemical purity prior to purification by HPLC. The general feature of this approach allows the convenient synthesis of palmitic acid specifically labeled in the ω, ω-1 or ω-3 positions by using several [11C]-labeled alkyl iodides ([11C]MeI, [1-11C]EtI or [1-11C]BuI) in the same cross-coupling protocol.
- Wuest,Dence,McCarthy,Welch
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p. 1289 - 1300
(2007/10/03)
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- Inhibition of protein kinase Cα by dequalinium analogues: Dependence on linker length and geometry
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Analogues of a bipartite compound, dequalinium (DECA) (quinolinium, 1,1'-(1,10-decanediyl)bis(4-amino-2-methyl diiodide)), were tested for inhibition of protein kinase Cα (PKCα). In vitro assays of monomeric and dimeric analogues support a model in which DECA inhibits PKCα by an obligatory two-point contact, a unique mechanism among PKC inhibitors. The presence of unsaturation in the center of the C10-alkyl linker produced geometric isomers with different inhibitory potencies: cis IC50 = 52 ± 12 μM and trans IC50 = 12 ± 3 μM, where the trans isomer was equipotent to that of the saturated C10-DECA. DECA analogues with longer, saturated linkers (C12, C14, or C16) exhibited enhanced inhibitory potencies which reached a plateau with the C14-linker (IC50 = 2.6 ± 0.2 μM). Metastatic melanoma cells treated with 250 nM C12-, C14-, or C16-DECA and irradiated with long-wave UV light (which causes irreversible inhibition of PKCα by DECA) confirmed the linker-dependent inhibition of intracellular PKCα activity.
- Qin, Donghui,Sullivan, Regina,Berkowitz, William F.,Bittman, Robert,Rotenberg, Susan A.
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p. 1413 - 1417
(2007/10/03)
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- Quantum interference effects in self-assembled asymmetric disulfide monolayers: Comparisons between experiment and ab initio/Monte Carlo theories
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Electron transfer measurements between solution redox probes and a Au electrode coated with self-assembled monolayers of symmetric and asymmetric ??-hydroxyalkane disulfides are used to probe the quantum interference between hydrocarbon chains of different lengths. While ab initio theory predicts a measurable destructive interference effect between hydrocarbon chains differing in length by a single methylene unit, electron transfer rates for the ferricyanide and horse heart cytochrome c are more consistent with rates estimated in the absence of the interference effect. The discrepancy between theory and experiment is discussed in light of possible interchain electronic coupling and phase segregation within the monolayers and limitations of the theoretical models.
- Cheng, Jun,Miller, Cary J.
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p. 1058 - 1062
(2007/10/03)
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- Low-Frequency Raman Spectra of Even α,ο-Disubstituted n-Alkanes
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Low-frequency Raman spectra of even α,ο-disubstituted n-alkanes have been recorded.The major features in the spectra arise from whole-chain longitudinal and bending vibrations.The effects of end group, chain lenght, and temperature on the frequencies of these vibrations are described, and the frequencies of the longitudinal vibrations are interpreted in terms of the chain model of Minoni and Zerbi.
- Viras, Kyriakos,Viras, Fontini,Campbell, Carl,King, Terence A.,Booth, Colin
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p. 3479 - 3483
(2007/10/02)
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- SYNTHESIS OF FOUR n-ALKANES WITH TERMINAL DIPOLAR SUBSTITUENTS
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12-Nitrododecanol, 1,12-dinitrododecane, 1,24-dinitrotetracontane and 2,15-diaminohexadecan-1,16-dioic acid were prepared from the common intermediate 12-bromododecanol.This bromoalcohol, being prepared from cyclododecanone, is free of homologous bifunctional impurities.The functionalised 24 carbon chain was prepared by a Wittig reaction of 12-bromododecanal with the triphenylphosphonium salt of 12-bromododecanal ethylene acetal using 'naked' carbonate anion to provide the base.The resulting bromoacetal was converted to 24-bromotetracont-12-enol, both this and the 12-bromododecanol were converted to the corresponding α,ω-di-iodides and then to the desired α,ω-dinitro compounds.The α-amino acid functionality can be introduced on an α,ω-dihalide with the anion of either diethyl 2-acetylaminopropan-1,3-dioate or benzylidene glycine ethyl ester.Also detailed is the previously unreported reduction of a carboxylic acid to an alcohol by borane-dimethyl sulphide in dichloromethane.
- Ainscow, T. A.,Belmont, M. R.,Henshall, J. L.,Hooper, R. M.,Simmonds, D. J.
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p. 115 - 122
(2007/10/02)
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