- Fatty Acid Cysteamine Conjugates as Novel and Potent Autophagy Activators That Enhance the Correction of Misfolded F508del-Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)
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A depressed autophagy has previously been reported in cystic fibrosis patients with the common F508del-CFTR mutation. This report describes the synthesis and preliminary biological characterization of a novel series of autophagy activators involving fatty acid cysteamine conjugates. These molecular entities were synthesized by first covalently linking cysteamine to docosahexaenoic acid. The resulting conjugate 1 synergistically activated autophagy in primary homozygous F508del-CFTR human bronchial epithelial (hBE) cells at submicromolar concentrations. When conjugate 1 was used in combination with the corrector lumacaftor and the potentiator ivacaftor, it showed an additive effect, as measured by the increase in the chloride current in a functional assay. In order to obtain a more stable form for oral dosing, the sulfhydryl group in conjugate 1 was converted into a functionalized disulfide moiety. The resulting conjugate 5 is orally bioavailable in the mouse, rat, and dog and allows a sustained delivery of the biologically active conjugate 1.
- Vu, Chi B.,Bridges, Robert J.,Pena-Rasgado, Cecilia,Lacerda, Antonio E.,Bordwell, Curtis,Sewell, Abby,Nichols, Andrew J.,Chandran, Sachin,Lonkar, Pallavi,Picarella, Dominic,Ting, Amal,Wensley, Allison,Yeager, Maisy,Liu, Feng
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Read Online
- "dual Layer" Self-Sorting with Cucurbiturils
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Platinum(II) complexes bearing terpyridyl (tpy) and thiolate ligands were used to test the design of a "dual layer" self-sorting system in the presence of Cucurbit[8]uril (CB[8]). Pt(II) thiolates and CB[8] form 2:1 assemblies, with both metallic centers sitting on top of one another at one of the macrocycle portals. We showed that any pair of these CB[8]-secured Pt(II) complex dimers bearing different tpy "heads" and thiolate "tails" scrambles to afford up to 10 ternary assemblies via two processes: (1) supramolecular exchanges (i.e., the egression and ingression of Pt complexes from and into CB[8]) and (2) ligand exchanges between the Pt thiolates. The mixtures of 10 assemblies were fully characterized by nuclear magnetic resonance spectroscopy. While the thiolate tails do not significantly affect the rate of the supramolecular exchanges, they were found to control (1) the kinetics of ligand exchange, with bulkier thiolates causing dramatic rate retardations, as well as (2) the thermodynamics of the self-sorting process, i.e., the distribution of assemblies at equilibrium, via intra-CB[8] assembly interactions between pairs of thiolates. Ligand exchanges are consistently slower than supramolecular exchanges. An associative pathway that involves the formation of dimers of CB[8]-secured Pt dimers (a total of 4 Pt complexes) during the ligand exchange process was invoked to rationalize the observed kinetics.
- Barbero, Héctor,Masson, Eric,Thompson, Nathan A.
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- LINAC/LASER determination of the absolute rate constant for thiyl and hydroxyl radical reaction with sulfhydryls in aqueous solution: Mercaptoethanol, cysteamine, and N-acetyl-L-cysteine
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The technique of combined pulse radiolysis/laser photolysis has been used to investigate the disulfide radical anion formation reactions for mercaptoethanol, cysteamine, and N-acetyl-L-cysteine over the pH range 7.0-13.0. The photolysis of the transient radical anions, formed by the one electron oxidation of the sulfhydryl, perturbs the disulfide radical anion/thiyl radical equilibrium, allowing rate constants for thiyl radical reaction with the parent sulfhydryl to be uniquely determined from the absorption bleach and subsequent recovery. These pH-dependent values were combined with measured disulfide radical anion equilibrium constants to calculate first-order disulfide radical anion dissociation rate constants. By computer modeling of established mechanisms for the disulfide radical anion growths, rate constants for the reaction of hydroxyl radicals with individual sulfhydryl species were calculated. These values are contrasted with previously reported values determined by using competition kinetics.
- Mezyk, Stephen P.
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Read Online
- Non-specific reaction inhibitor, method for inhibiting non-specific reaction, and kit
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Provided is a non-specific reaction inhibitor for achieving the accurate detection and quantitation of a trace component (a target substance) contained in a sample, in an immunoassay, by simply and effectively inhibiting a non-specific reaction associated with the measurement. The non-specific reaction inhibitor comprises a substance of the formula I: wherein R1 and R2 together form a double bond between carbons, to which they are respectively bonded directly, or R1 is a hydrogen atom and R2 is a group formed by removing H from an SH-group-containing compound, B is a support, and L is a spacer arm portion.
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- Taurine synthesis method (by machine translation)
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The invention provides a taurine synthesis method, and solves the problems of by-product accumulation, high temperature and high pressure in ammonia decomposition reaction, strong strong acid and strong base in acidification and the like in an addition reaction in a traditional taurine synthesis process. The method comprises the following steps: 1) carrying out cyclization reaction of sulfur solution and ethylene contact to obtain a solution of sulfur dissolved in carbon disulfide; 2) carrying out an addition reaction with ammonia or liquid ammonia contact to obtain an amino thiol; 3) carrying out an oxidation reaction in the presence of a catalyst to obtain the crude taurine. (by machine translation)
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Paragraph 0036; 0038; 0041; 0043; 0045; 0047; 0049; 0051
(2020/07/15)
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- Engineering a cleavable disulfide bond into a natural product siderophore using precursor-directed biosynthesis
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An analogue of the bacterial siderophore desferrioxamine B (DFOB) containing a disulfide motif in the backbone was produced from Streptomyces pilosus cultures supplemented with cystamine. Cystamine competed against native 1,5-diaminopentane during assembly. DFOB-(SS)1[001] and its complexes with Fe(iii) or Ga(iii) were cleaved upon incubation with dithiothreitol. Compounds such as DFOB-(SS)1[001] and its thiol-containing cleavage products could expand antibiotic strategies and Au-S-based nanotechnologies.
- Richardson-Sanchez, Tomas,Codd, Rachel
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supporting information
p. 9813 - 9816
(2018/09/10)
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- TUNABLE FLUORESCENCE USING CLEAVABLE LINKERS
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The invention relates to cleavable chemistry in general, and in particular, to tunable fluoresence using cleavable linkers present in fluorochrome-quencher conjugates.
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Paragraph 00118-00119
(2014/11/11)
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- POLY(ORGANOPHOSPHAZENE) COMPOSITION FOR BIOMATERIALS
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Provided are a use of chemically-crosslinkable, poly(organophosphazene)s for biomaterials, chemically-crosslinkable poly(organophosphazene)s with a physiologically active substance covalently-bonded thereto, a use thereof for biomaterials, and a process for preparing the same. The chemical crosslinkings can be made by UV irradiation, and/or a crosslinker, and/or an additive, and/or an enzyme, and/or a mixing of at least one polymer.
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- Poly(organophosphazene) composition for biomaterials
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Provided are a use of chemically-crosslinkable, poly(organophosphazene)s for biomaterials, chemically-crosslinkable poly(organophosphazene)s with a physiologically active substance covalently-bonded thereto, a use thereof for biomaterials, and a process for preparing the same. The chemical crosslinkings can be made by UV irradiation, and/or a crosslinker, and/or an additive, and/or an enzyme, and/or a mixing of at least one polymer.
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- Thiols and selenols as electron-relay catalysts for disulfide-bond reduction
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Pass them on! Dithiobutylamine immobilized on a resin is a useful reagent for the reduction of disulfide bonds. Its ability to reduce a disulfide bond in a protein is enhanced greatly if used along with a soluble strained cyclic disulfide or mixed diselenide that relays electrons from the resin to the protein. This electron-relay catalysis system provides distinct advantages over the use of excess soluble reducing agent alone. Copyright
- Lukesh III, John C.,VanVeller, Brett,Raines, Ronald T.
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supporting information
p. 12901 - 12904
(2014/01/06)
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- BINARY AND TERTIARY GALVANIC PARTICULATES AND METHODS OF MANUFACTURING AND USE THEREOF
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The present invention relates to galvanic particulates, their methods of manufacture and uses in treatments are described. The galvanic particulates may be binary or tertiary galvanic particulates, for example, containing multiple layers or phases of conductive materials.
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- Methyltransferase-directed derivatization of 5-hydroxymethylcytosine in DNA
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Sequence-specific derivatization: Enzymatic methylation of cytosine in DNA is part of an epigenetic regulatory network in vertebrates. In the absence of the methylation cofactor S-adenosyl-L-methionine, bacterial cytosine-5 methyltransferases can catalyze the condensation of aliphatic thiols and selenols with 5-hydroxymethylcytosine, a recently discovered nucleobase in mammalian DNA, to yield 5-chalcogenomethyl derivatives (see scheme).
- Liutkeviaciute, Zita,Kriukiene, Edita,Grigaityte, Indre,Masevieius, Viktoras,Klimasauskas, Saulius
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supporting information; experimental part
p. 2090 - 2093
(2011/04/23)
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- Polymers with structure-defined functions
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An alternating copolymer comprising a backbone of residues of a maleic anhydride derivative and those of a compound containing vinylic unsaturation, which also comprises residues of an active compound containing a nucleophilic group, bound to the backbone by a residue of the nucleophilic group, including such copolymer comprising residues of an active compound containing alcohol, thiol or amine group. The chemical and biological propertieis of actives, such as protease inhibitors, neurotransmitter drugs, and other small molecule active drugs, are enhanced, and new applications enabled. Also, artefacts, including a solid medical implant device, dressing or scaffold or a fluid adhesive or medicinal composition comprising such a polymer, and a method of use of such polymer, including a method for the treatment or prophylaxis of wounds
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- A retro-inverso TAT-like peptide designed to deliver cysteamine to cells
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A retro-inverso, TAT-like peptide wherein lysine residues are replaced with cysteine residues bearing a disulfide-linked cysteamine group is found to engage in thiol-disulfide exchange with cysteine. These peptides are transported into cells and localize to lysosomes. Cellular uptake is enhanced in peptides bearing two cysteamine groups over those with one or none, by factors of approximately 1.5 and 12, respectively.
- Lim, Jongdoo,Pellois, Jean-Philippe,Simanek, Eric E.
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supporting information; experimental part
p. 6321 - 6323
(2010/12/18)
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- Reductive demercuration in deprotection of trityl thioethers, trityl amines, and trityl ethers
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A room-temperature deprotection method of trityl amines, -ethers, and -thioethers is presented, based on coupling of metal acid catalysis (HgX2, with X- = Cl- or OAc-) and sodium borohydride reduction. The results of its application to monotritylated compounds (ethanethiol, ethanol, and piperidine) and to mono- and ditritylated 1,2-bifunctional compounds (mercaptoethanol, aminoethanethiol, and ethanolamine) are compared with those obtained with early methods based on the use of strong Bronsted acids (pure TFA and MeCN solutions of HCl). Trityl thioethers of simple thiols and amino and hydroxy thiols are promptly cleaved by reductive detritylation, and one-pot procedures can be employed to produce free thiols. In contrast, dilution with water of these same compounds in solutions of strong Bronsted acids leaves them unaffected. O-Tr and N-Tr bonds are broken by this latter treatment. However, trityl ethers are rapidly cleaved by even dilute HCl solutions, while cleaving of trityl amines is modulated by HCl concentration. Addition of NaBH4 to solutions of monofunctional trityl ethers in HgCl2/MeCN leads to complete deprotection. Monofunctional trityl amines are partially deprotected only if the complexation reaction is allowed to reach equilibrium. Combination of H+- with HgX+-catalyzed detritylation methods allows selective deprotection of pertritylated amino and hydroxy thiols. The results appear to be due to the strong difference in the affinity of the donor atoms present in the pertritylated substrates for H+ and HgX+. Catalysis based on Bronsted acids leads to cleaving of the N- and O-trityl bonds with recovering of the S-trityl group; that based on mercury salts allows recovering of N- and O-trityl groups with deprotection of the -SH function. Selectivity in deprotection of pertritylated amino alcohols seems to be severely hampered by similarity in the affinity of N- and O-atoms for H+ and HgX+, and, taking advantage of the lower HgX+-complexation rate of the N-trityl with respect to the O-trityl group, only preservation of the N-trityl bond has been achieved.
- Maltese
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p. 7615 - 7625
(2007/10/03)
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- Equilibrium and kinetics studies of transnitrosation between S-nitrosothiols and thiols
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Using UV-vis spectrometrical measurements, equilibrium constants for NO transfer between S-nitroso-N-acetyl-penicillamine (SNAP) and different thiols as well as kinetic data for NO transfer from S-nitroso bovine serum albumin (BSANO) to thiols have been obtained. NO transfer from SNAP to other primary/secondary thiols are thermodynamically favorable, whereas other S-nitrosothiols exhibit similar NO transfer potential. The obtained Gibbs free energy, enthalpy and entropy data indicated that NO transfer reactions from SNAP to four thiols are exothermic with entropy loss. The kinetic behavior of BSANO/RSH transfer can be related to both the acidity of sulfhydryl group and the electronic structure in thiol.
- Wang, Kun,Wen, Zhong,Zhang, Wei,Xian, Ming,Cheng, Jin-Pei,Wang, Peng George
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p. 433 - 436
(2007/10/03)
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- Reactivity of sulfur nucleophiles towards S-nitrosothiols
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Rate constants have been measured for the reactions of a range of S-nitrosothiols with the following sulfur-centred nucleophiles: sulfite ion, thiourea, thiocyanate ion, thiosulfate ion, thiomethoxide ion and sulfide ion. Many of the reactions were very fast and were followed in a stopped-flow spectrophotometer. For the sulfite reaction the reactive species over the pH range 4-8 was shown to be exclusively SO32-. For two RSNO species the reactivity sequence was established as: SO32- > MeS- > S2O32- ? SC(NH2)2 SCN-. The reaction with sulfide ion was also rapid and generated a fairly stable yellow species (λmax 410 nm), which was probably the nitrosodisulfide ion ONSS-, but the absorbance-time data were too complex for a simple kinetic analysis. This reaction could have some potential as an analytical procedure for the determination of RSNO species. The kinetic results are discussed in terms of the factors affecting nucleophilicity and are compared with the corresponding reactions of other nitrosating species.
- Munro, Andrew P.,Williams, D. Lyn H.
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p. 1794 - 1797
(2007/10/03)
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- Reaction of ascorbic acid with S-nitrosothiols: Clear evidence for two distinct reaction pathways
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Ascorbate reacts with S-nitrosothiols generally, in the pH range 3-13 by way of two distinct pathways, (a) at low [ascorbate], typically below ～1 × 10-4 mol dm-3 which leads to the formation of NO and the disulfide, and (b) at higher [ascorbate] when the products are the thiol and NO. Reaction (a) is Cu2+-dependent, and is completely cut out in the presence of EDTA, whereas reaction (b) is totally independent of [Cu2+] and takes place readily whether EDTA is present or not. For S-nitrosoglutathione (GSNO) the two reactions can be made quite separate, although for some reactants the two reactions overlap. In reaction (a), ascorbate acts as a reducing agent, generating Cu+ from Cu2+, which in turn reacts with RSNO forming initially NO, Cu2+ and RS-. The latter can then play the role of reducing agent for Cu2+, leading to disulfide formation. Ascorbate will initiate reaction when the free thiolate has initially been reduced to a very low level by the synthesis of RSNO from a large excess of nitrous acid over the thiol. Reaction (b) is interpreted in terms of nucleophilic attack by ascorbate at the nitroso-nitrogen atom, leading to thiol and O-nitrosoascorbate which breaks up, by a free-radical pathway, to give dehydroascorbic acid and NO. A similar pathway is the accepted mechanism in the literature for the nitrosation of ascorbate by nitrous acid and alkyl nitrites. The rate constant for the Cu2+-independent pathway increases sharply with pH and analysis of the variation of the rate constant with pH identifies a reaction pathway via both the mono- and di-anion forms of ascorbate, with the latter being the more reactive. As expected the entropy of activation is large and negative. Some aspects of structure-reactivity trends are discussed.
- Holmes, Anthony J.,Williams, D. Lyn H.
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p. 1639 - 1644
(2007/10/03)
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- 2,3-disubstituted cyclopentanone derivatives, process for producing the same, and medicinal use thereof
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The present invention relates to a compound represented by the following general formula (1) STR1 (wherein X represents O, S, SO, SO2, or NH, Y is a substituted or unsubstituted hydrocarbon residue containing 1 through 6 carbon atoms and having an overall molecular weight of not less than 15 and not more than 400, and the hydrocarbon residue, when the residue is ring, may contain one or two hetero-atoms in the ring, and Z is a carboxyl group, a group derived therefrom or an aliphatic hydrocarbon residue having from 1 to 4 carbon atoms which may be substituted or unsabstituted) or a pharmacologically acceptable salt thereof (excluding (1R,2S)-2-[(2R)-(2-acetyl-amino-2-carboxyethyl)thiomethyl]-3-oxo-1-cyclopentane-carboxylic acid (cystacyclin)), a method for production thereof and a medicinal use thereof. The compound of the present invention is useful as a neuron differentiation accelerator.
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- Process for producing d,1-5-methyltetrahydrofolic acid and its salts
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A method for preparing d,1-5-methyltetrahydrofolic acid and the salts thereof of the formula: STR1 wherein X is hydrogen, an alkaline metal or alkaline earth metal; by reduction of folic acid with sodium borohydride followed by the methylation of the tetrahydrofolic acid thus obtained with aqueous solutions of formaldehyde and sodium borohydride in an inert atmosphere.
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- Kinetics and Equilibria of Thiol/Disulfide Interchange Reactions of Selected Biological Thiols and Related Molecules with Oxidized Glutathione
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Rate constants for reaction of coenzyme A and cysteine with oxidized glutathione (GSSG) and equilibrium constants for the reaction of coenzyme A, cysteine, homocysteine, cysteamine, and related thiols with GSSG by thiol/disulfide interchange were determined over a range of pD values by NMR spectroscopy.The rate constants for reaction of the thiolate anion forms of coenzyme A and cysteine with GSSG suggest that reduction of GSSG by coenzyme A and cysteine is a mechanistically uncomplicated SN2 reaction.Equilibrium constants for the thiol/disulfide interchange reactions show a strong dependence on the Bronsted basicity of the thiolate anion.In a similar way, ΔE0', the difference between the half-cell potentials for the RSSR/RSH and GSSG/GSH redox couples, is linearly dependent on the difference between the pKA values of RSH and glutathione: ΔE0' = 64ΔpKA - 7.7 where ΔE0' is in units of mV.The reducing strength at a given pH is also determined by the fraction of the thiol present in the reactive thiolate form.At pD 7, the half-cell potentials for coenzyme A, cysteine, homocysteine, and cysteamine are close to that of glutathione, the major intracellular thiol redox system, which suggests that small changes in the intracellular redox potential can cause significant changes in the intracellular distribution of these biological thiols between their reduced and oxidized forms.
- Keire, David A.,Strauss, Erin,Guo, Wei,Noszal, Bela,Rabenstein, Dallas L.
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p. 123 - 127
(2007/10/02)
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- Synthesis of antiulcer compounds
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To synthesize molecules with antiulcer action, specifically ranitidine, niperotidine and cimetidine, having the formula: STR1 wherein R1 is hydrogen or together with R2 represents the rest of a cycloaliphatic or heterocyclic optionally substituted ring with 5 or 6 carbon atoms, R2 represents H, alkyl, alkyl substituted with a simple or substituted aromatic ring or with a single or substituted heterocyclic ring, Ar represents a simple or substituted phenyl group, a simple or substituted heterocyclic aromatic group, N=1, 2, 3, 4, 5 or 6 and X represents CH--NO2, S, N--C N, the compound (II) is prepared through the following process sequence: STR2 wherein Z=H, NO2, halogen and R3 =--(CH2)n Ar, --(CH2)n --SH, --(CH2)n --S--S--(CH2)n, --(CH2)n --S--CH2 Ar Y being halogen. The urea of formula STR3 is converted in a first stage into the corresponding carbodiimide STR4 by reaction with triphenylphosphine and bromine in the presence of a strong base and in a second stage is obtained the desired compound by reaction with nitromethane or with a saline derivative of cynamide.
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- Nitrosoureas compounds preparation thereof and utilization thereof in anticancerous
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Compounds having the general formula (I), STR1 wherein X and Y represent individually H or --NO, at least one of them being a group-NO, n is 0, 1 or 2, R represents hydrogen, an aliphatic, cycloaliphatic, cycloaliphatic-alkyl, aryl or aralkyl radical, or a group of formula, STR2 wherein R1 is a lower alkyl radical or an aryl, all these radicals being optionally substituted. The present invention also relates to the compounds hereabove defined in the form of mixtures of their position isomers. Furthermore, the present invention discloses processes for preparing such compounds, as well as compositions, useful particularly in anticancerous chemotherapy, containing at least one of said compounds as an active principle.
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- Amides of leurosine, leuroformine, desacetylleurosine and desacetylleuroformine
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C-3 Carboxamides of leurosine, leuroformine, 4-desacetylleurosine and 4-desacetylleuroformine, useful as antitumor agents.
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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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- Novel polytriazine compounds
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Novel tetraalkyl piperidine radical containing polytriazine compounds are produced by reacting a dihalogen-triazine with a bifunctional compound containing amine, alcohol, mercaptan or phenol groups at least one of the bifunctional compounds containing a tetraalkyl piperidine radical. The compounds are valuable light stabilizers for synthetic polymers, particularly polyolefin in the form of fibers or films.
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