- Total synthesis of gymnorrhizol, an unprecedented 15-membered macrocyclic polydisulfide from the Chinese mangrove bruguiera gymnorrhiza
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The total synthesis of gymnorrhizol, a naturally occurring macrocyclic polydisulfide with a new skeleton and a potent proteintyrosinephosphatase 1B inhibitor, was prepared in three steps, starting from (R)-1-bromo-3- chloroisopropanol and 1,3-dichloropropan-2-ol.
- Gong, Jing-Xu,Shen, Xu,Yao, Li-Gong,Jiang, Hualiang,Krohn, Karsten,Guo, Yue-Wei
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Read Online
- A fast response and red emission probe for mammalian thioredoxin reductase
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The first red emission off-on probe, TRFS-red, for thioredoxin reductase was reported. Compared to the previous green emission probe TRFS-green, TRFS-red maintains a high selectivity to the redox enzyme yet with improved response rate and sensitivity.
- Ma, Huilong,Zhang, Junmin,Zhang, Zhenzhe,Liu, Yaping,Fang, Jianguo
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Read Online
- A small molecule probe reveals declined mitochondrial thioredoxin reductase activity in a Parkinson's disease model
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The first off-on probe, Mito-TRFS, for imaging the mitochondrial thioredoxin reductase (TrxR2) in live cells was reported. In a cellular model of Parkinson's disease (PD), Mito-TRFS staining discloses a drastic decline of the TrxR2 activity, providing a mechanistic link of TrxR2 dysfunction to the etiology of PD.
- Liu, Yaping,Ma, Huilong,Zhang, Liangwei,Cui, Yajing,Liu, Xiaoting,Fang, Jianguo
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Read Online
- Loss of thioredoxin reductase function in a mouse stroke model disclosed by a two-photon fluorescent probe
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Thioredoxin reductase (TrxR) enzymes are critical in regulating redox homeostasis in cells. We report the first two-photon fluorescent probe of mammalian TrxR (TP-TRFS). TP-TRFS retains high specificity in recognizing TrxR. More importantly, the two-photon absorbing character of TP-TRFS enables it to be used in vivo. With the aid of TP-TRFS, a remarkable decline of the TrxR function was observed in the brain of a mouse model of stroke for the first time, providing a mechanistic link of TrxR dysfunction with stroke. This journal is
- Zhao, Jintao,Qu, Yuan,Gao, Hao,Zhong, Miao,Li, Xinming,Zhang, Fang,Chen, Yaxiong,Gan, Lu,Hu, Guodong,Zhang, Hong,Zhang, Shengxiang,Fang, Jianguo
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supporting information
p. 14075 - 14078
(2020/11/21)
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- Molecular rods based on oligo-spiro-thioketals
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We report on an extension of the previously established concept of oligospiroketal (OSK) rods by replacing a part or all ketal moieties by thioketals leading to oligospirothioketal (OSTK) rods. In this way, some crucial problems arising from the reversible formation of ketals are circumvented. Furthermore, the stability of the rods toward hydrolysis is considerably improved. To successfully implement this concept, we first developed a number of new oligothiol building blocks and improved the synthetic accessibility of known oligothiols, respectively. Another advantage of thioacetals is that terephthalaldehyde (TAA) sleeves, which are too flexible in the case of acetals can be used in OSTK rods. The viability of the OSTK approach was demonstrated by the successful preparation of some OSTK rods with a length of some nanometers.
- Wessig,Gerngro?,Freyse,Bruhns,Przezdziak,Schilde,Kelling
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p. 1125 - 1136
(2016/02/19)
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- Highly selective off-on fluorescent probe for imaging thioredoxin reductase in living cells
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The first fluorescent probe for mammalian thioredoxin reductase (TrxR), TRFS-green, was designed, synthesized, and fully evaluated. The probe features a 1,2-dithiolane scaffold with a quenched naphthalimide fluorophore. TRFS-green displays a green fluorescence off-on change induced by the TrxR-mediated disulfide cleavage and subsequent intramolecular cyclization to liberate the masked naphthalimide fluorophore. It was demonstrated in vitro that TRFS-green manifests high selectivity toward TrxR over other related enzymes and various small molecule thiols as well as biological reducing molecules. HPLC analyses indicated that TRFS-green was exclusively converted to naphthalimide catalyzed by TrxR. The ability in triggering on the fluorescence signal by cellular protein extracts correlates well with the endogenous TrxR activity in different cells. Furthermore, inhibition of TrxR by 2,4-dinitrochlorobenzene or depletion of TrxR by immunoprecipitation remarkably decreases the reduction of TRFS-green by cellular protein extracts. Finally, TRFS-green was successfully applied in imaging TrxR activity in living cells. The fluorescence signal of TRFS-green in living cells was inhibited by pretreating the cells with TrxR inhibitor in a dose-dependent manner, potentiating the development of living cell-based screening assay for identifying TrxR inhibitors. We expect the novel fluorescent probe TRFS-green would facilitate the discovery of TrxR-targeting small molecules for potential therapeutic agents and provide significant advances in understanding the physiological/pathophysiological functions of TrxR in vivo.
- Zhang, Liangwei,Duan, Dongzhu,Liu, Yaping,Ge, Chunpo,Cui, Xuemei,Sun, Jinyu,Fang, Jianguo
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p. 226 - 233
(2014/01/23)
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- Selective synthesis of isomeric dithioglycerols
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Reactions of 2,3-dibromopropan-1-ol and 1,3-dichloropropan-2-ol with elemental sulfur activated in the system hydrazine hydrate-2-aminoethanol at 30-35°C gave oligomeric polysulfides which were subjected to reductive cleavage with formation of individual dithioglycerol isomers. Activation of sulfur with the use of alkali gives rise to mixtures of isomeric products.
- Levanova,Grabel'nykh,Sukhomazova,Zemirova,Russavskaya,Albanov,Klyba,Zhanchipova,Korchevin
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experimental part
p. 1428 - 1433
(2009/06/08)
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- YELLOW COMPOUND AND WATER-BASED INK-JET RECORDING INK CONTAINING THE COMPOUND
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Aqueous ink for ink-jet recording which contains at least a water-insoluble coloring matter, water and a resin as main components and which takes the form of an emulsion, in which is characterized by containing at least one yellow hue coloring matter selected from the group consisting of a quinophthalone compound represented by the formula (1); and a pyridone azo compound represented by the formula (2); The ink is ink for ink-jet recording having excellent light resistance and storage stability, and enables formation of a high quality image without blotting, and obtained recording image is excellent in water resistance as ink for ink-jet recording.
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- Aqueous ink for ink jet recording
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Aqueous ink for ink jet recording which contains at least a water-insoluble coloring matter, water and a resin as main components and which takes the form of an emulsion, the coloring matter being represented by formula (1) The coloring matter for ink jet recording of the invention is excellent in water resistance in particular and also excellent in light resistance and compatibility with the resin. Thus, it is suited for ink jet recording. Further, the aqueous ink for ink jet recording of the invention which is produced using the coloring matter is excellent in light resistance and storage stability. Especially, when it is used as ink for ink jet recording system, the use of the ink composition can provide excellent aqueous ink that enables formation of a high-quality image without blotting and a recorded image having an excellent water resistance.
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- Reduction of thiokols in the system hydrazine hydrate-base as a new route to alkanedithiols
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A new procedure for preparative synthesis of alkanedithiols from simple commercially available products is based on reduction of the S-S bond in appropriate polyalkylene disulfides (thiokols) in the system hydrazine hydrate-base. Thiokols were prepared by reaction of dihaloalkanes with Na2S2 or K2S2 generated from elemental sulfur and alkali in aqueous hydrazine hydrate. Reaction of 1,2-dibromocyclohexane with sodium or potassium disulfide yields bis(2-bromocyclohexyl) sulfide as the only product.
- Alekminskaya,Russavskaya,Korchevin,Deryagina,Trofimov
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p. 732 - 737
(2007/10/03)
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- Rate Constants and Equilibrium Constants for Thiol-Disulphide Interchange Reactions Involving Oxidized Glutathione
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The rate of reduction of oxidized glutathione (GSSG) to glutathione (GSH) by thiolate (RS-) follows a Broensted relation in pKas of the conjugate thiols (RSH): βnuc ca. 0.5.This value is similar to that for reduction of Ellman's reagent: βnuc ca. 0.4 - 0.5.Analysis of a number of rate and equilibrium data, taken both from this work and from the literature, indicates that rate constants, k, for a range of thiolate-disulphide interchange reactions are correlated well by equations of the form log k = C + βnucpKanuc + βcpKac + βlgpKalg ( nuc = nucleophile, c = central, and lg = leaving group sulfur): eq 36 - 38 give representative values of the Broensted coefficients.The values of these Bronsted coefficients are not sharply defined by the available experimental data, although eq 36 - 38 provide useful kinetic models for rates of thiolate-disulfide interchange reactions.The uncertainty in these parameters is such that their detailed mechanistic interpretation is not worthwhile, but their qualitative interpretation - that all three sulphur atoms experience a significant effective negative charge in the transition state, but that the charge is concentrated on the terminal sulfurs - is justified.Equilibrium constants for reduction of GSSG using α,ω-dithiols have been measured.The reducing potential of the dithiol is strongly influenced by the size of the cyclic disulfide formed on its oxidation: the most strongly reducing dithiols are those which can form six-membered cyclic disulfides.Separate equilibrium constants for thiolate anion-disulphide interchange (KS-) and for thiol-disufide interchange (KSH) have been estimated from literature data: KS- is roughly proportional to 2ΔpKa is the difference between the pKas of the two thiols involved in the interchange.The contributions of thiol pKa values to the observed equilibrium constants for reduction of GSSG with α,ω-dithiols appear to be much smaller than those ascribable to the influence of structure on intramolecular ring formation.These equilibrium and rate constants are helpful in choosing dithiols for use as antioxidants in solutions containing proteines: dithiothreitol (DTT), 1,3-dimercapto-2-propanol (DMP), and 2-mercaptoethanol have especially useful properties.
- Szajewski, Richard P.,Whitesides, George M.
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p. 2011 - 2026
(2007/10/02)
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