77874-90-9Relevant articles and documents
Tuning Structures and Properties for Developing Novel Chemical Tools toward Distinct Pathogenic Elements in Alzheimer's Disease
Han, Jiyeon,Lee, Hyuck Jin,Kim, Kyu Yeon,Lee, Shin Jung C.,Suh, Jong-Min,Cho, Jaeheung,Chae, Junghyun,Lim, Mi Hee
, p. 800 - 808 (2018)
Multiple pathogenic factors [e.g., amyloid-β (Aβ), metal ions, metal-bound Aβ (metal-Aβ), reactive oxygen species (ROS)] are found in the brain of patients with Alzheimer's disease (AD). In order to elucidate the roles of pathological elements in AD, chemical tools able to regulate their activities would be valuable. Due to the complicated link among multiple pathological factors, however, it has been challenging to invent such chemical tools. Herein, we report novel small molecules as chemical tools toward modulation of single or multiple target(s), designed via a rational structure-property-directed strategy. The chemical properties (e.g., oxidation potentials) of our molecules and their coverage of reactivities toward the pathological targets were successfully differentiated through a minor structural variation [i.e., replacement of one nitrogen (N) or sulfur (S) donor atom in the framework]. Among our compounds (1-3), 1 with the lowest oxidation potential is able to noticeably modify the aggregation of both metal-free Aβ and metal-Aβ, as well as scavenge free radicals. Compound 2 with the moderate oxidation potential significantly alters the aggregation of Cu(II)-Aβ42. The hardly oxidizable compound, 3, relative to 1 and 2, indicates no noticeable interactions with all pathogenic factors, including metal-free Aβ, metal-Aβ, and free radicals. Overall, our studies demonstrate that the design of small molecules as chemical tools able to control distinct pathological components could be achieved via fine-tuning of structures and properties.
Enhanced photoinduced electron transfer at the surface of charged lipid bilayers
Limburg, Bart,Laisne, Guillaume,Bouwman, Elisabeth,Bonnet, Sylvestre
, p. 8965 - 8972 (2014)
Photocatalytic systems often suffer from poor quantum yields due to fast charge recombination: The energy-wasting annihilation of the photochemically created charge-separated state. In this report, we show that the efficiency of photoinduced electron tran
5-(2-Aminoethyl)dithio-2-nitrobenzoate as a more base-stable alternative to ellman's reagent
Zhu, Jinge,Dhimitruka, Ilirian,Pei, Dehua
, p. 3809 - 3812 (2007/10/03)
(Chemical Equation Presented) 5-(2-Aminoethyl)dithio-2-nitrobenzoate (ADNB) reacts with free thiols with kinetics similar to those of Ellman's reagent but has dramatically improved stability under alkaline conditions, making it an excellent alternative to Ellman's reagent for the quantitation of thiol contents and enzymatic assays under basic pH conditions.
On the Cleavage of Ellman's Reagent by Dithonite in the Presence of Dioctadecyldimethylammonium Chloride Surfactant Vesicles Laced with Cholesterol
Huffman, Robert W.,McBride, Phil,Brown, David M.
, p. 1633 - 1637 (2007/10/02)
Ellman's reagent (I) is distributed between the outer aqueous interface and the interior bilayer of DODAC vesicles upon contact when added to presonicated aqueous DODAC suspensions.This distribution also extends to the inner aqueous interface in about 10 min.This suspension reacts with aqueous alkaline sodium dithionite in two kinetic processes.The first process involves the bimolecular cleavage of I at the outer aqueous interface instantaneously.This is followed by a slow reaction of the same due to leakage of the bilayer-embedded substrate to the outer interface.This condition changes, however, when the DODAC vesicles are laced with cholesterol by cosonication of the aqueous solutions.Both Ellman's reagent and the reduced anion II product of cleavage by dithionite now are impermeable to this membrane but the protonated III does penetrate the bilayer.This result is indicated by loss of absorbance at 440 nm concurrent with gain in absorbance at 320 nm upon contact between III and cholesterol-laced vesicles.This result is interpreted in terms of the known permeability changes accompanying the incorporation of cholesterol into the vesicles.Thus Ellman's reaggent (I) can be encapsulated by DODAC vesicles if they contain cholesterol in such a way that they are unreachable by dithionite and lyate species.
Reactivity Control by Microencapsulation in Simple Ammonium Ion Vesicles
Moss, Robert A.,Swarup, Shanti,Zhang, Hongmei
, p. 2914 - 2919 (2007/10/02)
The quantitative oxidation of Ellman's anion (2) to Ellman's reagent by o-iodosobenzoate (4) can be kinetically controlled by microencapsulation in vesicles of dioctadecyldimethylammonium chloride (DODAC (1b)).Reactions at pH 8 between 2 and excess 4 occur rapidly on the surface of DODAC vesicles (k ca. 0.16-0.24 s-1).When either 2 or 4 is encapsulated within the DODAC vesicles, rapid reaction with the other exovesicular reagent does not occur; instead, a slow (k ca. (2-7) 1E-3 s-1) permeation-limited oxidation is observed, in which 4 is probably the key permeant.Individually encapsulated 2 and 4 react with each other only to the extent of ca. 5-10percent over 20 h, a rate retardation >18000 relative to the unmodulated exovesicular reaction.Similarly, the cleavage of Ellman's anion (2) by dithionite can be controlled by DODAC vesicles.The rapid, exovesicular cleavage (k ca. 33-35 s-1) disappeaers when endovesicular 3 is challanged by exovesicilar dithionite and is replaced by the slow (k ca. (5-7) 1E-4 s-1) hydrolysis of 3.In contrast to the observed facile vesicular DODAC control of these anion-anion reactions, the cleavage of neutral p-nitrophenyl diphenyl phosphate by 4 is not strongly affected by encapsulation of either substrate or 4.
VARIABLE STOICHIOMETRY IN THE DECOMPOSITION OF AROMATIC DISULFIDES IN ALKALINE SOLUTION. ON THE PROPERTIES OF 3-CARBOXYLATE-4-NITROBENZENESULFENATE ION
Blakeley, Robert L.,Riddles, Peter W.,Zerner, Burt
, p. 127 - 136 (2007/10/02)
The alkaline hydrolysis of low concentrations of the aromatic disulfide 5,5'-dithiobis(2-nitrobenzoic acid) in 3.0M NaOH, quantitatively forms 3-carboxylate-4-nitrobenzenesulfenate ion as expected for a simple displacement of the thiophenoxide ion by hydroxide ion.In the absence of residual disulfide, the sulphenate ion is stable, apart from slow oxidation to the corresponding sulfinate ion.The red sulfinate ion has an absorption maximum at 492 +/- 2nm with a molar absorption coefficient (ε) of 10.600 M-1 cm-1 at 490 nm.At high initial concentrations of disulfide or at lower concentrations of hydroxide ion, appreciable amounts of the sulfenate ion react with unreacted disulfide to form a transient sulfinic acid thiolester intermediate which decomposes to form the corresponding sulfinate ion and the thiophenoxide ion.This work constitutes the first unambiguous description of the mechanism and variable stoichiometry of the alkaline decomposition of an aromatic disulfide.
Nucleophilic Esterolytic and Displacement Reactions of a Micellar Thiocholine Surfactant
Moss, Robert A.,Bizzigotti, George O.,Huang, Ching-Wen
, p. 754 - 762 (2007/10/02)
The thiol-functionalized surfactant N-n-cetyl-N,N-dimethyl-N-(β-thioethyl)ammonium chloride, 4 (16-SH), was synthesized.Under micellar conditions at pH 7, excess micellar 16-SH cleaved p-nitrophenyl acetate (PNPA) with kψmax = 2.16 s
