- Factors affecting the hydrogen reduction kinetics of CsHSO4
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The hydrogen reduction of CsHSO4, including in the presence of catalysts, is studied. The main factors affecting the rate of the process are determined. A possible reaction mechanism through the surface hydrated phase is discussed. Experiments
- Ponomareva,Lavrova
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- on demand redox buffering by H2S contributes to antibiotic resistance revealed by a bacteria-specific H2S donor
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Understanding the mechanisms of antimicrobial resistance (AMR) will help launch a counter-offensive against human pathogens that threaten our ability to effectively treat common infections. Herein, we report bis(4-nitrobenzyl)sulfanes, which are activated by a bacterial enzyme to produce hydrogen sulfide (H2S) gas. We found that H2S helps maintain redox homeostasis and protects bacteria against antibiotic-triggered oxidative stress on demand , through activation of alternate respiratory oxidases and cellular antioxidants. We discovered, a hitherto unknown role for this gas, that chemical inhibition of H2S biosynthesis reversed antibiotic resistance in multidrug-resistant (MDR) uropathogenic Escherichia coli strains of clinical origin, whereas exposure to the H2S donor restored drug tolerance. Together, our study provides a greater insight into the dynamic defence mechanisms of this gas, modes of antibiotic action as well as resistance while progressing towards new pharmacological targets to address AMR.
- Shukla, Prashant,Khodade, Vinayak S.,Sharathchandra, Mallojjala,Chauhan, Preeti,Mishra, Saurabh,Siddaramappa, Shivakumara,Pradeep, Bulagonda Eswarappa,Singh, Amit,Chakrapani, Harinath
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- Thio sol-gel synthesis of titanium disulfide thin films and nanoparticles using titanium(IV) alkoxide precursors
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Titanium tetraisopropoxide reacts with hydrogen sulfide in butylamine solvent at room temperature to form an amorphous titanium alkoxy-sulfide which can be converted to crystalline titanium disulfide by heat treatment in a flowing hydrogen sulfide gas stream. The reaction has been studied using infrared and Raman spectroscopy, gas chromatography-mass spectrometry, X-ray diffractometry and energy-dispersive X-ray analysis measurements. Based on these studies, it is shown that a partially thiolysed alkoxide precursor forms through the replacement of a limited number of alkoxy groups by hydrosulfide moieties. This alkoxy-hydrosulfide is believed to form following a thiolysis-condensation mechanism similar to the hydrolysis-condensation process that occurs during the corresponding oxide sol-gel reaction. The alkoxy-hydrosulfide species can then be completely thiolysed at 800 °C in a stream of hydrogen sulfide to yield pure, hexagonal titanium disulfide in either film or particulate form.
- Let, Alexandru L.,Mainwaring, David E.,Rix, Colin J.,Murugaraj, Pandiyan
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- Titanium sulphide nanoclusters formed within inverse micelles
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High-quality, nano-sized clusters of TiS2 have been grown successfully inside inverse micellar cages and their optical properties studied. The clusters exhibit large blueshifts in the optical-absorption features with decreasing cluster size due to quantum confinement, affording control of the absorption thresholds and a demonstration of the crossover from band-like to molecule-like spectra as the size of the clusters becomes smaller than that of the exciton in the bulk. Crown Copyright
- Mainwaring, David E.,Let, Alexandru L.,Rix, Colin,Murugaraj, Pandiyan
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- Desulfurization of the Ni(100) Surface Using Gas-Phase Hydrogen Radicals
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Gas-phase hydrogen radicals cause desulfurization of the sulfided Ni(100) surface even for temperatures as low as 120 K, resulting in H2S formation. In contrast, no thermal desulfurization is observed in the presence of coadsorbed hydrogen. During hydrogen radical exposure, sulfur is abstracted from the Ni(100) surface by a sequential Eley-Rideal mechanism. After hydrogen radical exposure, two additional H2S formation pathways involving coadsorbed hydrogen are observed during subsequent heating. In the first pathway, H2S formation is observed at 150 K, involving a partially hydrogenated intermediate formed during gas-phase atomic hydrogen exposure. The second pathway involves addition of desorbing subsurface hydrogen to adsorbed sulfur, leading to H2S formation at 190 K. Both the temperature and coverage dependence of the 150 K pathway support a sequential hydrogen addition mechanism with a sulfhydryl intermediate during temperature-programmed desorption (TPD) studies. Previous H2S decomposition studies on this surface show that the sulfhydryl intermediate is not stable above ～190 K because of thermal dehydrogenation. The temperature dependence of H2S formation and sulfur removal during exposure to the gas-phase hydrogen radical is also consistent with a sulfhydryl intermediate. Above 200 K, no desulfurization is observed during gas-phase hydrogen radical exposure. This thermal dehydrogenation of H2S also depends on the coverage of coadsorbed sulfur. Increasing sulfur coverages inhibits dehydrogenation of both H2S and SH. With higher sulfur coverages, H2S desorption is favored and substantial sulfur is removed during temperature-programmed reaction spectroscopy (TPRS) experiments after low-temperature hydrogen radical exposure. Taken together, the temperature- and coverage-dependent behavior indicates that sulfhydryl is an intermediate for sulfur abstraction. Through control of gas-phase hydrogen radical exposure, vacancies in sulfided nickel layers were generated. Hydrogen chemisorption studies were used to probe these sulfur vacancies. The new, low-temperature hydrogen desorption peak at 230 K corresponds to hydrogen modified by coadsorbed sulfur.
- Capitano, Adam T.,Gland, John L.
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- Interaction between certain porphyrins and CdS colloids: A steady state and time resolved fluorescence quenching study
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The interaction between porphyrins namely, meso-tetrakis (4-methoxyphenyl)porphyrin (TMeOPP), protoporphyrin IX (PPIX) and Zinc(II) meso-tetraphenylporphyrin (ZnTPP) with colloidal CdS has been studied by using steady state and time resolved fluorescence quenching measurements. The porphyrins adsorbed on the surface of colloidal CdS due to electrostatic interaction. This adsorption leads to changes in the absorption spectra related to the complex formation. The apparent association constant (Kapp) was in the order of 4.34-5.58 × 105 M-1 from the effect of colloidal CdS on the absorption spectra and 0.64-1.6 × 105 M-1 from fluorescence quenching data. Quenching is attributable mainly to static mechanism through ground state complex formation as confirmed by lifetime measurements.
- Jhonsi, M. Asha,Kathiravan,Renganathan
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- LATTICE VIBRATION SPECTRA Part LXIV. Raman spectroscopic study of lithium hydrogensulfide LiSH: dynamic disorder and order-disorder phase transition
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Raman spectra (4000-50 cm-1) of lithium hydrogensulfide are recorded in the range from 70 to 300 K.The temperature dependence of frequencies and halfwidths of the SH- stretching and librational modes yields clear evidence for a disorder-order phase transition at 222 K and thermally activated dynamic disorder of the SH- ions in the room temperature polymorph.Down to 70 K the increasing splitting of the in-plane libration can be interpreted by a Landau-type order parameter.This splitting reflects increasing dynamic interactions (factor group splitting) of adjacent (in ) SH- ions due to the ordering process.The halfwidths of the stretching and out-of-plane librational modes exhibits an Arrhenius-type behaviour.The activation energies derived are 1.9 kJ mol-1 for both vibrations.The activation temperature (230 K) is in good agreement with that of the change of the specific heat at 228 K.The order mechanism and a plausible structure of the ordered phase below 222 K are discussed.
- Beckenkamp, K.,Lutz, H. D.,Jacobs, H.,Metzner, U.
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- Formation of branched fractal CdS patterns in oligomer LB monolayers: A study using transmission electron microscopy
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Transmission electron microscopy images of the treelike fractal aggregates of CdS nanoparticles in amphiphilic oligomer (polymaleic acid with octadecanol ester) LB matrix were observed. The features of these aggregates were developed into the micrometer regime. By changing the ratio between carboxylic groups and hydrocarbon chains, as well as the surface pressure, different fractal CdS patterns could be obtained. These results lead us to propose the mechanism of the formation of branchlike patterns, very much analogous to two-dimensional irreversible fractal-growth models such as diffusion-limited aggregates (DLA). Weak hydrophobic and hydrophilic interaction for interfacial molecular recognition at the organic/inorganic interface had been proposed as providing a possible elucidation for the formation of some aspects of a self-similar fractal-like pattern. At a ratio of 7:1, the fractal dimension was calculated by the box-counting method, and the dominant value was 1.69 ± 0.03, which was in good agreement with two-dimensional DLA.
- Li, Lin Song,Jin, Jian,Yu, San,Zhao, Yingying,Zhang, Chengxiang,Li, Tie Jin
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- Synthesis and photolysis of 3-tert-butyl-4-oxy(mercapto)-1,4-dihydropyrazolo[5,1-c][1,2,4]triazines
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Reactions of 3-tert-butyl- or 3,4-di-tert-butyl-substituted 8-methylpyrazolo[5,1-c][1,2,4]-triazines with trifluoroacetic anhydride afforded 1-(2,2,2-trifluoroacetyl)-1,4-dihydropyrazolo-[5,1-c][1,2,4]triazin-4-yl 2,2,2-trifluoroacetates. The treatment with H2X and RXH (X = O or S; R = Me or Et) of covalent trifluoroacetate that does not contain the But group at the C(4) atom allowed us to synthesize 1-(3-tert-butyl-4-R-pyrazolo[5,1-c][1,2,4]triazin-1(4H)-yl)-2,2,2-trifluoroethan-1-ones. The structure of 4-ethylthio derivative was fully established by the single-crystal X-ray diffraction analysis. The UV irradiation of obtained 2,2,2-trifluoroethan-1-ones leads to the aromatization of triazine ring. The UV photolysis of 1-trifluoroacetyl-4-hydroxy derivative has been proposed as a novel method for the photogeneration of acidity. Antimicrobial and antifungal activities of the synthesized compounds were evaluated.
- Ivanov, S. M.,Lyssenko, K. A.,Traven, V. F.
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- Synthesis and X-ray diffraction characterization of FeNdSbS4, an analog of berthierite
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A rare-earth-containing analog of the mineral berthierite, with the composition FeNdSbS4, was synthesized for the first time. FeNdSbS4 is isostructural with FeSb2S4 and crystallizes in orthorhombic symmetry (sp. gr. Pbam, Z = 4) with lattice parameters a = 11.395 A, b = 14.136 A, and c = 3.747 A.
- Gasymov,Gasymova,Aliev
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- Sulfur-33 Isotope Tracing of the Hydrodesulfurization Process: Insights into the Reaction Mechanism, Catalyst Characterization and Improvement
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The novel approach based on 33S isotope tracing is proposed for the elucidation of hydrodesulfurization (HDS) mechanisms and characterization of molybdenum sulfide catalysts. The technique involves sulfidation of the catalyst with 33S-isotope-labeled dihydrogen sulfide, followed by monitoring the fate of the 33S isotope in the course of the hydrodesulfurization reaction by online mass spectrometry and characterization of the catalyst after the reaction by temperature-programmed oxidation with mass spectrometry (TPO-MS). The results point to different pathways of thiophene transformation over Co or Ni-promoted and unpromoted molybdenum sulfide catalysts, provide information on the role of promoter and give a key for the design of new efficient HDS catalysts.
- Sushkevich, Vitaly L.,Popov, Andrey G.,Ivanova, Irina I.
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- Polymersome Wound Dressing Spray Capable of Bacterial Inhibition and H2S Generation for Complete Diabetic Wound Healing
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Diabetic wounds are difficult to heal due to recurrent bacterial infection, decreased proliferation, and migration of epidermal and endothelial cells. This is related to impaired leukocyte function and low blood concentrations of H2S in diabetic patients. Herein, an antibacterial polymersome-based wound dressing spray was demonstrated for complete diabetic wound healing. The designed polymersome was self-assembled from poly(?-caprolactone)24-block-poly[lysine15-stat-(S-aroylthiooxime)23] [PCL24-b-P(Lys23-stat-SATO15)], where PCL is the hydrophobic membrane-forming block and P(Lys-stat-SATO) acts as a hydrophilic stabilizer block. The polymersomes can penetrate and kill Gram-positive and Gram-negative bacteria because of the electrostatic interaction induced by the antibacterial P(Lys23-stat-SATO15) block. Furthermore, the SATO segments are capable of long-term H2S generation by reacting with cysteine (up to 12 h). This promotes proliferation, migration of epidermal and endothelial cells, and angiogenesis. Overall, this polymersome-based wound dressing spray acts as a bacterial inhibitor and H2S generator and offers a fresh insight into the effective treatment of diabetic wounds.
- Liu, Danqing,Liao, Yuyao,Cornel, Erik Jan,Lv, Mingchen,Wu, Tong,Zhang, Xinyue,Fan, Liujie,Sun, Min,Zhu, Yunqing,Fan, Zhen,Du, Jianzhong
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p. 7972 - 7985
(2021/11/01)
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- N-Methylation of Self-Immolative Thiocarbamates Provides Insights into the Mechanism of Carbonyl Sulfide Release
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Hydrogen sulfide (H2S) is an important biomolecule, and self-immolative thiocarbamates have shown great promise as triggerable H2S donors with suitable analogous control compounds; however, thiocarbamates with electron-deficient payloads are less efficient H2S donors. We report here the synthesis and study of a series of N-methylated esterase-triggered thiocarbamates that block the postulated unproductive deprotonation-based pathway for these compounds. The relative reaction profiles for H2S release across a series of electron-rich and electron-poor N-Me aniline payloads are examined experimentally and computationally. We show that thiocarbamate N-methylation does block some side reactivity and increases the H2S release profiles for electron-poor donors. Additionally, we show that isothiocyanate release is not a competitive pathway, and rather that the reduced efficiency of electron-poor donors is likely due to other side reactions.
- Levinn, Carolyn M.,Mancuso, Jenna L.,Lutz, Rachel E.,Smith, Haley M.,Hendon, Christopher H.,Pluth, Michael D.
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p. 5443 - 5451
(2021/05/07)
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- Generation of H2S from Thiol-Dependent NO Reactivity of Model [4Fe-4S] Cluster and Roussin's Black Anion
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Iron-sulfur clusters (Fe-S) have been well established as a target for nitric oxide (NO) in biological systems. Complementary to protein-bound studies, synthetic models have provided a platform to study what iron nitrosylated products and byproducts are produced depending on a controlled reaction environment. We have previously shown a model [2Fe-2S] system that produced a dinitrosyl iron complex (DNIC) upon nitrosylation along with hydrogen sulfide (H2S), another important gasotransmitter, in the presence of thiol, and hypothesized a similar reactivity pattern with [4Fe-4S] clusters which have largely produced inconsistent reaction products across biological and synthetic systems. Roussin's black anion (RBA), [Fe4(μ3-S)3(NO)7]-, is a previously established reaction product from synthetic [4Fe-4S] clusters with NO. Here, we present a new reactivity for the nitrosylation of a synthetic [4Fe-4S] cluster in the presence of thiol and thiolate. [Et4N]2[Fe4S4(SPh)4] (1) was nitrosylated in the presence of excess PhSH to generate H2S and an "RBA-like"intermediate that when further reacted with [NEt4][SPh] produced a {Fe(NO)2}9 DNIC, [Et4N][Fe(NO)2(SPh)2] (2). This "RBA-like"intermediate proved difficult to isolate but shares striking similarities to RBA in the presence of thiol based on IR υ(NO) stretching frequencies. Surprisingly, the same reaction products were produced when the reaction started with RBA and thiol. Similar to 1/NO, RBA in the presence of thiol and thiolate generates stoichiometric amounts of DNIC while releasing its bridging sulfides as H2S. These results suggest not only that RBA may not be the final product of [4Fe-4S] + NO but also that RBA has unprecedented reactivity with thiols and thiolates which may explain current challenges around identifying biological nitrosylated Fe-S clusters.
- Oakley, Kady M.,Zhao, Ziyi,Lehane, Ryan L.,Ma, Ji,Kim, Eunsuk
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p. 15910 - 15917
(2021/07/20)
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- Evolution of Structural, Thermal, Optical, and Vibrational Properties of Sc2S3, ScCuS2, and BaScCuS3 Semiconductors
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In the present work, we report on the synthesis of Sc2S3, ScCuS2 and BaScCuS3 powders using a method based on oxides sulfidation and modification of their properties. The crystal structures and morphology of samples are verified by XRD and SEM techniques. Thermal stability has been studied by DTA which has revealed that Sc2S3 decomposes to ScS through melting at 1877 K. ScCuS2 and BaScCuS3 melt incongruently at temperatures of 1618 K and 1535 K, respectively. The electronic structure calculations show that the investigated compounds are semiconductors with indirect band gap (Eg). According to the diffuse reflection spectroscopy, Sc2S3, ScCuS2 and BaScCuS3 are wide-bandgap semiconductors featured the Eg values of 2.53 eV, 2.05 eV and 2.06 eV, respectively. The band gap decreases with the introduction of copper (I) and barium cations into the crystal structure of the compounds. Variation of local structure has been verified by Raman and infrared spectroscopy. The calculated vibrational modes of ScCuS2 correspond to CuS4 and Sc?S layer vibrations, even though ScS6 octahedra-like structural units can be found in the structure.
- Aleksandrovsky, Aleksandr S.,Andreev, Oleg V.,Azarapin, Nikita O.,Leonidov, Ivan I.,Maximov, Nikolai G.,Oreshonkov, Aleksandr S.,Razumkova, Illaria A.,Shestakov, Nikolai P.
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p. 3355 - 3366
(2021/08/23)
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- A Dinuclear Persulfide-Bridged Ruthenium Compound is a Hypoxia-Selective Hydrogen Sulfide (H2S) Donor
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Hydrogen sulfide (H2S) is a gaseous molecule that has received attention for its role in biological processes and therapeutic potential in diseases, such as ischemic reperfusion injury. Despite its clinical relevance, delivery of H2S to biological systems is hampered by its toxicity at high concentrations. Herein, we report the first metal-based H2S donor that delivers this gas selectively to hypoxic cells. We further show that H2S release from this compound protects H9c2 rat cardiomyoblasts from an in vitro model of ischemic reperfusion injury. These results validate the utility of redox-activated metal complexes as hypoxia-selective H2S-releasing agents for use as tools to study the role of this gaseous molecule in complex biological systems.
- Woods, Joshua J.,Wilson, Justin J.
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supporting information
p. 1588 - 1592
(2020/11/30)
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- In Vitro Reconstitution of a Five-Step Pathway for Bacterial Ergothioneine Catabolism
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Ergothioneine is a histidine-derived sulfur metabolite that is biosynthesized by bacteria and fungi. Plants and animals absorb ergothioneine as a micronutrient from their environment or nutrition. Several different mechanisms of microbial ergothioneine production have been described in the past ten years. Much less is known about the genetic and structural basis for ergothioneine catabolism. In this report, we describe the in vitro reconstitution of a five-step pathway that degrades ergothioneine to l-glutamate, trimethylamine, hydrogen sulfide, carbon dioxide, and ammonia. The first two steps are catalyzed by the two enzymes ergothionase and thiourocanate hydratase. These enzymes are closely related to the first two enzymes in histidine catabolism. However, the crystal structure of thiourocanate hydratase from the firmicute Paenibacillus sp. reveals specific structural features that strictly differentiate the activity of this enzyme from that of urocanate hydratases. The final two steps are catalyzed by metal-dependent hydrolases that share most homology with the last two enzymes in uracil catabolism. The early and late part of this pathway are connected by an entirely new enzyme type that catalyzes desulfurization of a thiohydantoin intermediate. Homologous enzymes are encoded in many soil-dwelling firmicutes and proteobacteria, suggesting that bacterial activity may have a significant impact on the environmental availability of ergothioneine.
- Beliaeva, Mariia A.,Leisinger, Florian,Seebeck, Florian P.
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p. 397 - 403
(2021/03/08)
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- Biochemical Characterization, Phytotoxic Effect and Antimicrobial Activity against Some Phytopathogens of New Gemifloxacin Schiff Base Metal Complexes
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String of Fe(III), Cu(II), Zn(II) and Zr(IV) complexes were synthesized with tetradentateamino Schiff base ligand derived by condensation of ethylene diamine with gemifloxacin. The novel Schiff base (4E,4′E)-4,4′-(ethane-1,2-diyldiazanylylidene)bis{7-[(4Z
- Mohamed, Amira A.,Elshafie, Hazem S.,Sadeek, Sadeek A.,Camele, Ippolito
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- Mechanochemical synthesis of air-stable hexagonal Li4SnS4-based solid electrolytes containing LiI and Li3PS4
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Sulfide solid electrolytes with high ionic conductivity and high air stability must be developed for manufacturing sulfide all-solid-state batteries. Li10GeP2S12-type and argyrodite-type solid electrolytes exhibit a high ionic conductivity of ～10-2 S cm-1 at room temperature, while emitting toxic H2S gas when exposed to air. We focused on hexagonal Li4SnS4 prepared by mechanochemical treatment because it comprises air-stable SnS4 tetrahedra and shows higher ionic conductivity than orthorhombic Li4SnS4 prepared by solid-phase synthesis. Herein, to enhance the ionic conductivity of hexagonal Li4SnS4, LiI was added to Li4SnS4 by mechanochemical treatment. The ionic conductivity of 0.43LiI·0.57Li4SnS4 increased by 3.6 times compared with that of Li4SnS4. XRD patterns of Li4SnS4 with LiI showed peak-shifting to lower angles, indicating that introduction of I-, which has a large ionic radius, expanded the Li conduction paths. Furthermore, Li3PS4, which is the most air-stable in the Li2S-P2S5 system and has higher ionic conductivity than Li4SnS4, was added to the LiI-Li4SnS4 system. We found that 0.37LiI·0.25Li3PS4·0.38Li4SnS4 sintered at 200 °C showed the highest ionic conductivity of 5.5 × 10-4 S cm-1 at 30 °C in the hexagonal Li4SnS4-based solid electrolytes. The rate performance of an all-solid-state battery using 0.37LiI·0.25Li3PS4·0.38Li4SnS4 heated at 200 °C was higher than those obtained using Li4SnS4 and 0.43LiI·0.57Li4SnS4. In addition, it exhibited similar air stability to Li4SnS4 by formation of LiI·3H2O in air. Therefore, addition of LiI and Li3PS4 to hexagonal Li4SnS4 by mechanochemical treatment is an effective way to enhance ionic conductivity without decreasing the air stability of Li4SnS4.
- Kobayashi, Hironori,Kuratani, Kentaro,Otoyama, Misae
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p. 38880 - 38888
(2021/12/20)
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- Use of Dithiasuccinoyl-Caged Amines Enables COS/H2S Release Lacking Electrophilic Byproducts
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The enzymatic conversion of carbonyl sulfide (COS) to hydrogen sulfide (H2S) by carbonic anhydrase has been used to develop self-immolating thiocarbamates as COS-based H2S donors to further elucidate the impact of reactive sulfur species in biology. The high modularity of this approach has provided a library of COS-based H2S donors that can be activated by specific stimuli. A common limitation, however, is that many such donors result in the formation of an electrophilic quinone methide byproduct during donor activation. As a mild alternative, we demonstrate here that dithiasuccinoyl groups can function as COS/H2S donor motifs, and that these groups release two equivalents of COS/H2S and uncage an amine payload under physiologically relevant conditions. Additionally, we demonstrate that COS/H2S release from this donor motif can be altered by electronic modulation and alkyl substitution. These insights are further supported by DFT investigations, which reveal that aryl and alkyl thiocarbamates release COS with significantly different activation energies.
- Cerda, Matthew M.,Mancuso, Jenna L.,Mullen, Emma J.,Hendon, Christopher H.,Pluth, Michael D.
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supporting information
p. 5374 - 5380
(2020/03/19)
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- Insights into the Mechanism of Thiol-Triggered COS/H2S Release from N-Dithiasuccinoyl Amines
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The hydrolysis of carbonyl sulfide (COS) to form H2S by carbonic anhydrase has been demonstrated to be a viable strategy to deliver H2S in a biological system. Herein, we describe N-dithiasuccinoyl amines as thiol-triggered COS/H2S donors. Notably, thiol species especially GSH and homocysteine can trigger the release of both COS and H2S directly from several specific analogues via an unexpected mechanism. Importantly, two representative analogues Dts-1 and Dts-5 show intracellular H2S release, and Dts-1 imparts potent anti-inflammatory effects in LPS-challenged microglia cells. In conclusion, N-dithiasuccinoyl amine could serve as promising COS/H2S donors for either H2S biological studies or H2S-based therapeutics development.
- Zhou, Shengchao,Mou, Yujie,Liu, Miao,Du, Qian,Ali, Basharat,Ramprasad, Jurupula,Qiao, Chunhua,Hu, Li-Fang,Ji, Xingyue
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p. 8352 - 8359
(2020/09/07)
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- Novel synthesis method of chlorolucanthone
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The invention discloses a novel synthesis method of chlorolucanthone, and belongs to the technical field of chemical engineering. The method comprises the following steps: firstly, adding a sodium hydrosulfide solution into a hydrogen sulfide generator, then dropwise adding an acid into the hydrogen sulfide generator, and guiding generated gas into a preheated pipeline reactor; pumping preheated p-dichlorobenzene into the pipeline reactor, reacting the p-dichlorobenzene with hydrogen sulfide gas, cooling a reaction product to obtain liquid and gas, and rectifying and purifying the liquid to obtain mercaptochlorobenzene; secondly, adding a reaction solvent and an alkali into a flask, stirring, adding mercaptochlorobenzene and o-chlorobenzoic acid, carrying out a reflux reaction, and carrying out aftertreatment after the reaction is finished so as to obtain an intermediate 2-carboxyl-4'-chlorodiphenyl sulfide; and finally, adding 2-carboxyl-4'-chlorodiphenyl sulfide into concentrated sulfuric acid, carrying out an intramolecular cyclization dehydration reaction, and purifying after the reaction is ended so as to obtain the target product. The method disclosed by the invention is simple and convenient to operate, mild in reaction condition, clean and environment-friendly, and high in product yield and purity.
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Paragraph 0021; 0029-0030; 0034-0035; 0039-0040; 0044-0045
(2020/10/21)
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- Reversible uptake of sulfur-containing gases by single crystals of a Cr 8 metallacrown
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The exposure of green crystals of the [CrF(O2CtBu)2]8Cr8 metallacrown to SO2 and H2S gases results in the binding of the gas molecules in the internal molecular cavity, despite the absence of any pores or channels in the structure. Single crystal X-ray diffraction studies show that the gas molecules bind weakly to the bridging fluoride ligands. The desorption process was followed by TGA, DSC and in situ variable temperature single crystal X-ray diffraction, obtaining the gas binding energies for the gas guest molecules. These results are supported by DFT calculations.
- Vitórica-Yrezábal, I?igo J.,Sava, Daniel Florin,Reta, Daniel,Timco, Grigore A.,Winpenny, Richard E. P.
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supporting information
p. 13184 - 13189
(2019/09/18)
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- Study of dry- and wet-process amorphous arsenic sulfides: Synthesis, Raman reference spectra, and identification in historical art materials
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This paper reports the dry and wet synthetic procedures and characterization by Raman spectroscopy of amorphous arsenic sulfide reference pigments. Reference spectra of two amorphous materials obtained by wet process methods and four dry process references of amorphous arsenic sulfide pigments of known composition are presented and discussed. While all materials present a main band characteristic for the amorphous pigment centered on 341?cm?1, additional small contributions indicate the presence of sulfur, arsenic oxide, and crystalline nano phases embedded in the amorphous matrix. Although only the broad 341-cm?1 peak is necessary to identify the arsenic sulfide as an amorphous material, the smaller additional features allow for the characterization of the various manufacturing processes and initial materials used. In ideal conditions, these small features also enable to assess the As/S ratio of the studied amorphous arsenic sulfide pigments based on their relative intensity. In this context, the latter reference spectra were used to characterize the amorphous arsenic sulfide pigments and their arsenic to sulfur elemental composition in four 18th- to 20th-century historical samples and compared with scanning electron microscopy with energy dispersive X-ray semiquantitative analyses. The identification of the amorphous arsenic sulfide used in these historical samples was compared with the description of the manufacturing processes reported in historical sources of the time, allowing for a better understanding of the evolution of the amorphous arsenic sulfide pigments manufacturing methods.
- Vermeulen, Marc,Palka, Karel,Vl?ek, Miroslav,Sanyova, Jana
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p. 396 - 406
(2019/01/04)
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- Cyclic Sulfenyl Thiocarbamates Release Carbonyl Sulfide and Hydrogen Sulfide Independently in Thiol-Promoted Pathways
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Hydrogen sulfide (H2S) is an important signaling molecule that provides protective activities in a variety of physiological and pathological processes. Among the different types of H2S donor compounds, thioamides have attracted attention due to prior conjugation to nonsteroidal anti-inflammatory drugs (NSAIDs) to access H2S-NSAID hybrids with significantly reduced toxicity, but the mechanism of H2S release from thioamides remains unclear. Herein, we reported the synthesis and evaluation of a class of thioamide-derived sulfenyl thiocarbamates (SulfenylTCMs) that function as a new class of H2S donors. These compounds are efficiently activated by cellular thiols to release carbonyl sulfide (COS), which is quickly converted to H2S by carbonic anhydrase (CA). In addition, through mechanistic investigations, we establish that COS-independent H2S release pathways are also operative. In contrast to the parent thioamide-based donors, the SulfenylTCMs exhibit excellent H2S releasing efficiencies of up to 90percent and operate through mechanistically well-defined pathways. In addition, we demonstrate that the sulfenyl thiocarbamate group is readily attached to common NSAIDs, such as naproxen, to generate YZ-597 as an efficient H2S-NSAID hybrid, which we demonstrate releases H2S in cellular environments. Taken together, this new class of H2S donor motifs provides an important platform for new donor development.
- Pluth, Michael D.,Steiger, Andrea K.,Zhao, Yu
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supporting information
(2019/09/06)
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- Effects of sulfane sulfur content in benzyl polysulfides on thiol-triggered H2S release and cell proliferation
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Investigations into hydrogen sulfide (H2S) signaling pathways have demonstrated both the generation and importance of persulfides, which are reactive sulfur species that contain both reduced and oxidized sulfur. These observations have led researchers to suggest that oxidized sulfur species, including sulfane sulfur (S0), are responsible for many of the physiological phenomena initially attributed to H2S. A common method of introducing S0 to biological systems is the administration of organic polysulfides, such as diallyl trisulfide (DATS). However, prior reports have demonstrated that commercially-available DATS often contains a mixture of polysulfides, and furthermore a lack of structure-activity relationships for organic polysulfides has limited our overall understanding of different polysulfides and their function in biological systems. Advancing our interests in the chemical biology of reactive sulfur species including H2S and S0, we report here our investigations into the rates and quantities of H2S release from a series of synthetic, pure benzyl polysulfides, ranging from monosulfide to tetrasulfide. We demonstrate that H2S is only released from the trisulfide and tetrasulfide, and that this release requires thiol-mediated reduction in the presence of cysteine or reduced glutathione. Additionally, we demonstrate the different effects of trisulfides and tetrasulfides on cell proliferation in murine epithelial bEnd.3 cells.
- Bolton, Sarah G.,Cerda, Matthew M.,Gilbert, Annie K.,Pluth, Michael D.
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p. 393 - 398
(2019/01/04)
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- Controllable thioester-based hydrogen sulfide slow-releasing donors as cardioprotective agents
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Hydrogen sulfide (H2S) is an important signaling molecule with promising protective effects in many physiological and pathological processes. However, the study of H2S has been impeded by the lack of appropriate H2S donors that could mimic its slow-releasing process in vivo. Herein, we report the rational design, synthesis, and biological evaluation of a series of thioester-based H2S donors. These cysteine-activated H2S donors release H2S in a slow and controllable manner. Most of the donors comprising an allyl moiety showed significant cytoprotective effects in H9c2 cellular models of oxidative damage. The most potent donor 5e decreased the mitochondrial membrane potential (MMP) loss and lactate dehydrogenase (LDH) release in H2O2-stimulated H9c2 cells. More importantly, donor 5e exhibited a potent cardioprotective effect in an in vivo myocardial infarction (MI) mouse model by reducing myocardial infarct size and cardiomyocyte apoptosis. Taken together, our studies demonstrated that these new allyl thioesters are potential cardioprotective agents by releasing H2S.
- Yao, Hong,Luo, Shanshan,Liu, Junkai,Xie, Shaowen,Liu, Yanpeng,Xu, Jinyi,Zhu, Zheying,Xu, Shengtao
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supporting information
p. 6193 - 6196
(2019/06/07)
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- Novel spectral manipulations for determinations of Tolnaftate along with related toxic compounds: Drug profiling and a comparative study
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A comparative study using novel quadruple divisor and mean centering of ratio spectra spectrophotometric methods was developed for resolution of five- component mixture of Tolnaftate, β-naphthol (Tolnaftate alkaline degradation product and its toxic impurity), methyl(m-tolyl)carbamic acid (Tolnaftate alkaline degradation product), N-methyl-m-toluidine (Tolnaftate toxic impurity) and methyl paraben (as a preservative). For the novel quadruple divisor method, each component in the quinary mixture was determined by dividing the quinary mixture spectrum by a sum of standard spectrum of equal concentration of the other four components as a quadruple divisor. First derivative of each ratio spectra was then obtained which allowed selective determination of each component without interference from other components in the mixture. The second method was mean centering of ratio spectra that depended on utilizing the mean centered ratio spectra in four successive steps leading to enhancement of the signal to noise ratio. The absorption spectra of the five studied components were recorded in the wavelength range of 210–350 nm. The mean centered fourth ratio spectra amplitudes for each component were used for its determination. The developed methods were successfully applied for determination of laboratory prepared quinary mixtures to ensure method's specificity, then, were further applied on Tinea Cure cream where no interference from excipients. For the first time, Tolnaftate was determined along with its toxic impurity; β-naphthol, that could be absorbed by the skin, causing systemic toxic effects, unlike Tolnaftate that poorly absorbed, indicating the significance of this work. The proposed methods were statistically compared with each other and with the reference method. Furthermore, ICH guidelines were followed for their validation.
- Emam, Raghda A.,Abdelrahman, Maha M.,Abdelaleem, Eglal A.,Ali, Nouruddin W.
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- Acyl Selenyl Sulfides as the Precursors for Reactive Sulfur Species (Hydrogen Sulfide, Polysulfide, and Selenyl Sulfide)
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Persulfides are receiving increased attention due to their links to hydrogen sulfide (H2S) and hydrogen polysulfide (H2Sn). Their close analogues selenyl sulfides (RSeSHs), however, have limited literature precedent, and their reactivity and possible role in biology are largely unknown. Here, we devised an acyl selenyl sulfide template to study RSeSH chemistry. Their stability and reactivity toward amines/thiols were studied. These compounds can produce H2S or H2S2 under different conditions, suggesting that RSeSHs are possible intermediates.
- Hamsath, Akil,Wang, Yingying,Yang, Chun-Tao,Xu, Shi,Ca?edo, Danica,Chen, Wei,Xian, Ming
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supporting information
p. 5685 - 5688
(2019/08/01)
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- Controlled release of hydrogen sulfide significantly reduces ROS stress and increases dopamine levels in transgenic: C. elegans
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Hydrogen sulfide, an endogenous signalling molecule, is central to several pathophysiological processes in mammalian systems. It scavenges reactive oxygen species and is known to ameliorate dopaminergic neuronal degeneration in neurotoxin-induced Parkinson's disease models. The rapid volatilization of H2S from spontaneously releasing sulfide salts being a challenge, we describe peptide conjugates which exhibit tris(2-carboxyethyl)phosphine mediated "slow and sustained" H2S release. These conjugates reduced hydrogen peroxide-induced oxidative stress and significantly increased dopamine levels in transgenic C. elegans.
- Ali, Rafat,Pal, Hilal Ahmad,Hameed, Rohil,Nazir, Aamir,Verma, Sandeep
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supporting information
p. 10142 - 10145
(2019/08/30)
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- Development of Acid-Mediated H2S/COS Donors That Respond to a Specific pH Window
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Hydrogen sulfide (H2S) is a biologically relevant molecule, and recent efforts have focused on developing small molecular donors that deliver H2S on demand. Acid-activated donors have garnered significant interest due to the potential application of such systems in myocardial ischemia injury or for suppressing tumor growth. In this work, we report a new strategy for tuning H2S delivery to a specific pH window. Specifically, we utilize self-immolative thiocarbamates with an imine-derived triggering group. After imine hydrolysis, the self-immolative decomposition releases carbonyl sulfide (COS), which is quickly hydrolyzed to H2S by carbonic anhydrase. Although acid-mediated hydrolysis results in imine cleavage, environments that are too acidic result in protonation of the aniline intermediate and results in inhibition of COS/H2S release. Taken together, this mechanism enables access to donor motifs that are only activated within specific pH windows. Here, we demonstrate the design, preparation, and pH evaluation of a series of imine-based COS/H2S donor motifs, which we anticipate that will have utility in investigating H2S in acidic microenvironments.
- Gilbert, Annie K.,Zhao, Yu,Otteson, Claire E.,Pluth, Michael D.
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p. 14469 - 14475
(2019/10/11)
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- Characterization of Dialkyldithiophosphates as Slow Hydrogen Sulfide Releasing Chemicals and Their Effect on the Growth of Maize
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Hydrogen sulfide is a key gasotransmitter for plants and has been shown to greatly increase their growth and survival in the presence of environmental stressors. Current methods for slowly releasing hydrogen sulfide use chemicals, such as GYY-4137, but these result in the release of chemicals not found in the environment, and chemicals used may lack structures that can be readily tuned to affect the rate of release of hydrogen sulfide. In this article, we describe the synthesis and slow release of hydrogen sulfide from dialkyldithiophosphates, which are a new set of hydrogen sulfide releasing chemicals that can be used in agriculture. The rates of hydrolysis of dibutyldithiophosphate and GYY-4137 were measured in water at 85 °C and compared with each other to investigate their differences. GYY-4137 is widely used as a chemical that slowly releases H2S, but its rate of release was not previously quantified. The release of hydrogen sulfide in water at room temperature was measured for a series of dialkyldithiophosphates using a hydrogen sulfide electrode. It was shown that the structure of the dialkyldithiophosphate affected the amount of hydrogen sulfide released. The final degradation products of dibutyldithiophosphate were shown to be phosphoric acid and butanol, which are chemicals found in the environment. This result was notable because it demonstrated that dialkyldithiophosphates degrade to safe, natural chemicals that will not pollute the environment. To demonstrate that dialkyldithiophosphates have potential applications in agriculture, maize was grown for 4.5 weeks after exposure to 1-200 mg of dibutyldithiophosphate, and the weight of corn plants increased by up to 39% at low loadings of dibutyldithiophosphate.
- Carter, Justin M.,Brown, Eric M.,Irish, Erin E.,Bowden, Ned B.
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- Real-time monitoring of a photoactivated hydrogen persulfide donor for biological entities
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Hydrogen persulfide (H2S2) plays an important role in sulfur-based redox signaling mechanisms. Herein, we developed a visible light activated ESIPT based H2S2 donor using a p-hydroxyphenacyl phototrigger. The unique feature of the designed H2S2 donor system is the ability to monitor the H2S2 release in real time through a non-invasive fluorescence color change approach, with the color changing from green to blue. Next, we demonstrated the detection and quantification of H2S2 using a fluorescein based "turn-on" fluorescent probe. Furthermore, in vitro studies of the designed H2S2 donor demonstrated the real-time monitored H2S2 release and cytoprotective ability in the highly oxidizing cellular environment of MDA-MB-468 cells.
- Chaudhuri, Amrita,Venkatesh, Yarra,Jena, Bikash Chandra,Behara, Krishna Kalyani,Mandal, Mahitosh,Singh, N.D. Pradeep
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supporting information
p. 8800 - 8805
(2019/10/22)
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- Synthesis and Upconversion Luminescence in LaF3:Yb3+, Ho3+, GdF3: Yb3+, Tm3+ and YF3:Yb3+, Er3+ obtained from Sulfide Precursors
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Rare earth fluorides are mainly obtained from aqueous solutions of oxygen-containing precursors. Probably, this method is simple and efficient, however, oxygen may partially be retained in the fluoride structure. We offer an alternative method: obtaining fluorides and solid solutions based on them from an oxygen-free precursor. As starting materials, we choose sulfides of rare-earth elements and solid solutions based on them. The fluorination is carried out by exposure to hydrofluoric acid of various concentrations. The transmission electron microscopy images revealed the different morphologies of the products, which depend on the concentration of the fluorinating component (HF) and the host element. The solid solution particle size varied from 30–35 nm in the case of GdF3:Yb3+, Tm3+ (4 % HF) to larger structures with dimensions exceeding 200 nm, such as that for LaF3:Yb3+, Ho3+ (40 % HF). The thermal characteristics, such as the temperatures of the transitions and melting and enthalpies, were determined for the solid solutions and simple fluorides. Applicability of the materials obtained as biological luminescent markers was tested on the example of upconversion luminescence, and good upconversion properties were detected.
- Razumkova, Illariia A.,Denisenko, Yuriy G.,Boyko, Andrey N.,Ikonnikov, Denis A.,Aleksandrovsky, Aleksandr S.,Azarapin, Nikita O.,Andreev, Oleg V.
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p. 1393 - 1401
(2020/01/02)
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- Esterase-sensitive trithiane-based hydrogen sulfide donors
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1,3,5-Trithiane functionalized with esterase-sensitive ester groups on the methylene linkers was developed as a class of enzymatic hydrolysis-based hydrogen sulfide (H2S) donors. The amount of H2S released from the donors was dependent on the number of ester bonds. The donors release H2S in a controllable manner in the presence of an enzyme.
- Shyaka, Clovis,Xian, Ming,Park, Chung-Min
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p. 9999 - 10003
(2019/12/23)
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- Solid-phase hydrogen in a magnesium-carbon composite for efficient hydrogenation of carbon disulfide
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Desulfurization of syngas from coal gasification is an essential process in chemical synthesis to achieve high value-added utilization of coal. The hydrogenation conversion method is known for its high desulfurization degree in organic sulfur removal, but it is hindered by severe operating conditions, which leads to low safety and low efficiency. A Mg-carbon composite is synthesized by a reactive ball-milling method to store solid-phase hydrogen with high activity for CS2 hydrogenation. Without the presence of high-pressure gaseous hydrogen, CS2 in the stream is hydrogenated by the composite at 250 °C to yield CH4 and H2S, and the conversion achieved is over 91.8% in 300 min. First-principles calculations reveal that chemisorption structures can influence the reaction of CS2 with MgH2, in which horizontal chemisorption is in favor of the generation of gaseous H2S while vertical chemisorption can result in solid MgS. This new method of hydrogenation paves the way for organic sulfur compound removal at moderate temperatures without using a high-pressure hydrogen atmosphere.
- Chen, Haipeng,Han, Zongying,Feng, Xun,Liu, Pei,Liu, Jinqiang,Liu, Guilong,Yuan, Weiwei,Ren, Tianjiao,Zhou, Shixue
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supporting information
p. 3055 - 3062
(2018/02/22)
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- Catalytic Synthesis of Methylthiophenes
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The gas-phase reaction of dimethyl disulfide with thiophene over Co/HZSM-5 catalyst in a helium medium under atmospheric pressure at 250–350°C gave a mixture of mono-, di-, tri-, and tetramethylthiophenes with an overall selectivity of 94–96%.
- Mashkina,Khairulina
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p. 1794 - 1797
(2019/03/26)
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- Reactive Oxygen Species-Triggered Tunable Hydrogen Sulfide Release
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A series of carbamothioates with tunable release of H2S after activation by reactive oxygen species are reported. The half-lives of H2S release could be tuned from 24 to 203 min by varying the basicity of the amine.
- Chauhan, Preeti,Jos, Swetha,Chakrapani, Harinath
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p. 3766 - 3770
(2018/07/21)
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- Alternative pathway of H2S and polysulfides production from sulfurated catalytic-cysteine of reaction intermediates of 3-mercaptopyruvate sulfurtransferase
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It has been known that hydrogen sulfide and/or polysulfides are produced from a (poly)sulfurated sulfur-acceptor substrate of 3-mercaptopyruvate sulfurtransferase (MST) via thioredoxin (Trx) reduction in vitro. In this study, we used thiosulfate as the donor substrate and the catalytic reaction was terminated on the formation of a persulfide or polysulfides. We can present alternative pathway of production of hydrogen sulfide and/or polysulfides from (poly)sulfurated catalytic-site cysteine of reaction intermediates of MST via Trx reduction. Matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometric analysis revealed that after prolonged incubation of MST with thiosulfate, a trisulfide adduct becomes predominant at the sulfurated catalytic-site cysteine. When these adducts were reduced by Trx with reducing system (MST:Escherichia coli Trx:E. coli Trx reductase:NADPH = 1:5:0.02:12.5 molar ratio), liquid chromatography with tandem mass spectrometric analysis for monobromobimane-derivatized H2Sn revealed that H2S2 first appeared, and then H2S and H2S3 did later. The results were confirmed by high-performance liquid chromatography-fluorescence analysis.
- Nagahara, Noriyuki,Koike, Shin,Nirasawa, Takashi,Kimura, Hideo,Ogasawara, Yuki
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p. 648 - 653
(2018/01/27)
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- Y2S3 – Y2O3 phase diagram and the enthalpies of phase transitions
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A phase diagram of the Y2S3-Y2O3, system has been defined from 1000 K to melts for the first time; the enthalpies of phase transitions in the systems have been determined. The monoclinic phase δ-Y2S3 (P21/m, a = 1.7523(8) nm, b = 0.4010(9) nm, с = 1.0170(7) nm, β = 98.60(6)°; microhardness H = 411 ± 7 HV) transforms at 1716 ± 7 K to the unquenchable high-temperature phase ξ-Y2S3, ΔН = 29 ± 6 J/g (7.9 KJ/mol) as determined by DSC. The quenching can't latch the Y2S3-phase. The melting point of Y2S3 is 1888 ± 7 K; ΔН = 150 ± 28 J/g (41.1 KJ/mol). Y2OS2 has a monoclinic structure (P21/c, а = 0.8256(8) nm, b = 0.6879(8) nm, с = 0.6848(8) nm, β = 99.52(6), Н = 491 ± 13 HV) and melts incongruently at 1790 ± 8 K, ΔН = 190 ± 45 J/g (52 KJ/mol) by the scheme Y2OS2 ? Y2O2S + L (16 mol% Y2O3). Y2O2S has a hexagonal structure (a = 0.3784(5) nm, c= 0.6584(4) nm, Н = 654 ± 7 HV). Its congruent melting temperature is 2350 ± 40 K as determined by visual polythermal analysis (VPTA). The eutectic formed by Y2S3 and Y2OS2 phases has the composition 14.0 ± 0.5 mol% Y2O3 (0.58Y2S3 + 0.42Y2OS2) and melting temperature 1770 ± 6 K; ΔН = 215 ± 39 J/g. Between Y2O2S and Y2O3 phases, there is a eutectic with the coordinates 80 ± 1 mol% Y2O3 (0.6Y2O2S + 0.4Y2O3) and melting temperature 2150 ± 35 K (VPTA).
- Andreev,Pimneva
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- Cysteine-activated hydrogen sulfide (H2S) delivery through caged carbonyl sulfide (COS) donor motifs
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Hydrogen sulfide (H2S) is an important biomolecule, and controllable H2S donors are needed to investigate H2S biological functions. Here we utilize cysteine-mediated addition/cyclization chemistry to unmask an acrylate-functionalized thiocarbamate and release carbonyl sulfide (COS), which is quickly converted to H2S by carbonic anhydrase (CA).
- Zhao, Yu,Steiger, Andrea K.,Pluth, Michael D.
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supporting information
p. 4951 - 4954
(2018/05/23)
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- Visible to NIR Light Photoactivation of Hydrogen Sulfide for Biological Targeting
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The synthesis and photochemical properties of H2S-releasing BODIPY thiocarbamate photocage scaffolds activatable by visible-to-NIR (up to 700 nm) light to release carbonyl sulfide (COS), which is transformed to H2S using either isolated or natural carbonic anhydrase, is reported. The excellent uncaging cross section and high H2S release yields in in vitro experiments, including live-cell imaging, suggest that these photocages can serve as a platform for the bio-orthogonal phototriggered release within the tissue-transparent window.
- ?tacko, Peter,Muchová, Lucie,Vítek, Libor,Klán, Petr
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supporting information
p. 4907 - 4911
(2018/08/24)
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- Characterization and Biological Activity of a Hydrogen Sulfide-Releasing Red Light-Activated Ruthenium(II) Complex
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Hydrogen sulfide (H2S) is a biological gasotransmitter that has been employed for the treatment of ischemia-reperfusion injury. Despite its therapeutic value, the implementation of this gaseous molecule for this purpose has required H2S-releasing prodrugs for effective intracellular delivery. The majority of these prodrugs, however, spontaneously release H2S via uncontrolled hydrolysis. Here, we describe a Ru(II)-based H2S-releasing agent that can be activated selectively by red light irradiation. This compound operates in living cells, increasing intracellular H2S concentration only upon irradiation with red light. Furthermore, the red light irradiation of this compound protects H9c2 cardiomyoblasts from an in vitro model of ischemia-reperfusion injury. These results validate the use of red light-activated H2S-releasing agents as valuable tools for studying the biology and therapeutic utility of this gasotransmitter.
- Woods, Joshua J.,Cao, Jian,Lippert, Alexander R.,Wilson, Justin J.
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supporting information
p. 12383 - 12387
(2018/10/02)
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- Esterase-Sensitive Glutathione Persulfide Donor
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An esterase-sensitive glutathione persulfide (GSSH) donor (BW-GP-401) is described. The release profile was studied by monitoring the formation of lactone and direct trapping of GSSH with 1-fluoro-2,4-dinitrobenzene (DNFB). The donor was examined for its
- Yuan, Zhengnan,Zheng, Yueqin,Yu, Bingchen,Wang, Siming,Yang, Xiaoxiao,Wang, Binghe
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supporting information
p. 6364 - 6367
(2018/10/20)
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- Applications of Synthetic Organic Tetrasulfides as H2S Donors
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In an effort to expand the availability of simple polysulfides for H2S donation, we report here the synthesis and H2S release profiles of bis(aryl) and bis(alkyl) tetrasulfides. The tetrasulfide donors release H2S in a first-order dependence on reduced glutathione (GSH) and release more H2S than the commonly used trisulfide DATS.
- Cerda, Matthew M.,Hammers, Matthew D.,Earp, Mary S.,Zakharov, Lev N.,Pluth, Michael D.
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supporting information
p. 2314 - 2317
(2017/05/12)
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- Light-Activated COS/H2S Donation from Photocaged Thiocarbamates
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Hydrogen sulfide (H2S) is an important biomolecule, and responsive chemical tools for its delivery are needed. Here, we utilize the photocleavable o-nitrobenzyl group to unmask caged thiocarbamates and to access photoactivated H2S releasing molecules. These donors function by the initial release of carbonyl sulfide (COS), which is quickly hydrolyzed to H2S by carbonic anhydrase (CA). Our investigations demonstrate that o-nitrobenzyl-caged thiocarbamates can serve as a donor platform for the bio-orthogonal stimulated release of COS/H2S.
- Zhao, Yu,Bolton, Sarah G.,Pluth, Michael D.
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supporting information
p. 2278 - 2281
(2017/05/12)
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- Inhibition of Mitochondrial Bioenergetics by Esterase-Triggered COS/H2S Donors
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Hydrogen sulfide (H2S) is an important biological mediator, and synthetic H2S donating molecules provide an important class of investigative tools for H2S research. Here, we report esterase-activated H2S donors that function by first releasing carbonyl sulfide (COS), which is rapidly converted to H2S by the ubiquitous enzyme carbonic anhydrase (CA). We report the synthesis, self-immolative decomposition, and H2S release profiles of the developed scaffolds. In addition, the developed esterase-triggered COS/H2S donors exhibit higher levels of cytotoxicity than equivalent levels of Na2S or the common H2S donors GYY4137 and AP39. Using cellular bioenergetics measurements, we establish that the developed donors reduce cellular respiration and ATP synthesis in BEAS 2B human lung epithelial cells, which is consistent with COS/H2S inhibition of cytochrome c oxidase in the mitochondrial respiratory chain although not observed with common H2S donors at the same concentrations. Taken together, these results may suggest that COS functions differently than H2S in certain biological contexts or that the developed donors are more efficient at delivering H2S than other common H2S-releasing motifs.
- Steiger, Andrea K.,Marcatti, Michela,Szabo, Csaba,Szczesny, Bartosz,Pluth, Michael D.
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p. 2117 - 2123
(2017/08/23)
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- Triggered and Tunable Hydrogen Sulfide Release from Photogenerated Thiobenzaldehydes
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Hydrogen sulfide (H2S) has been identified as an important cell-signaling mediator and has a number of biological functions, such as vascular smooth muscle relaxation, neurotransmission, and regulation of inflammation. A facile and versatile approach for H2S production initiated by light irradiation and controlled by reaction with an amine or an amino acid was developed. The donor was synthesized in a one-pot reaction, and simple crystallization led to a yield of approximately 90 %. The synthetic strategy is scalable and versatile, and the H2S donors can be expressed ina number of different molecular and macromolecular forms, including crystalline small-molecule compounds, water-soluble polymers, polystyrene films, and hydrogels. The H2S donors based on polystyrene film and hydrogel were used as cell-culture scaffolds. The H2S donor based on water-soluble polymer was applied in photocontrolled inhibition of P-selectin expression on human platelets and subsequent regulation of platelet aggregation. This study provides the simplest controllable H2S source to study its biological functions. The developed materials are also new therapeutic platforms to deliver H2S, as there is no accumulation of toxic byproducts, and the donor materials from polystyrene films and hydrogels can be readily removed after releasing H2S.
- Xiao, Zeyun,Bonnard, Thomas,Shakouri-Motlagh, Aida,Wylie, Ross A. L.,Collins, Joe,White, Jonathan,Heath, Daniel E.,Hagemeyer, Christoph E.,Connal, Luke A.
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supporting information
p. 11294 - 11300
(2017/08/26)
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- Tuning the growth of Cu-MOFs for efficient catalytic hydrolysis of carbonyl sulfide
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Development of the high activity, promoter-free catalysts for carbonyl sulfide (COS) hydrolysis is important for the efficient utilization of various feedstocks. In this study, the Cu-based metal-organic framework HKUST-1 is synthesized by a simple and mild anodic-dissolution electrochemical method. The physical and chemical properties of the samples are characterized by several techniques, including scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller analysis and X-ray photoelectron spectroscopy. The results reveal that the synthesis voltage plays a crucial role in controlling the morphology of the resulting HKUST-1. The obtained samples function as novel catalysts for the hydrolysis of COS. A high efficiency, approaching 100%, can be achieved for the conversion of COS at 150 °C over the optimal HKUST-1 synthesized at 25 V. This is significantly higher than that of the sample prepared by the traditional hydrothermal method. Additionally, the effects of the water temperature and the flow velocity on the hydrolysis of COS are also investigated in detail. Finally, a possible reaction pathway of COS hydrolysis over HKUST-1 is also proposed. This work represents the first example of MOFs applied to the catalytic hydrolysis of COS. The results presented in this study can be anticipated to give a feasible impetus to design novel catalysts for removing the sulfur-containing compounds.
- Shen, Lijuan,Wang, Gaojie,Zheng, Xiaoxiao,Cao, Yanning,Guo, Yufeng,Lin, Ke,Jiang, Lilong
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p. 1373 - 1381
(2017/08/22)
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- Kinetic Insights into Hydrogen Sulfide Delivery from Caged-Carbonyl Sulfide Isomeric Donor Platforms
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Hydrogen sulfide (H2S) is a biologically important small gaseous molecule that exhibits promising protective effects against a variety of physiological and pathological processes. To investigate the expanding roles of H2S in biology, researchers often use H2S donors to mimic enzymatic H2S synthesis or to provide increased H2S levels under specific circumstances. Aligned with the need for new broad and easily modifiable platforms for H2S donation, we report here the preparation and H2S release kinetics from a series of isomeric caged-carbonyl sulfide (COS) compounds, including thiocarbamates, thiocarbonates, and dithiocarbonates, all of which release COS that is quickly converted to H2S by the ubiquitous enzyme carbonic anhydrase. Each donor is designed to release COS/H2S after the activation of a trigger by activation by hydrogen peroxide (H2O2). In addition to providing a broad palette of new, H2O2-responsive donor motifs, we also demonstrate the H2O2 dose-dependent COS/H2S release from each donor core, establish that release profiles can be modified by structural modifications, and compare COS/H2S release rates and efficiencies from isomeric core structures. Supporting our experimental investigations, we also provide computational insights into the potential energy surfaces for COS/H2S release from each platform. In addition, we also report initial investigations into dithiocarbamate cores, which release H2S directly upon H2O2-mediated activation. As a whole, the insights on COS/H2S release gained from these investigations provide a foundation for the expansion of the emerging area of responsive COS/H2S donor systems.
- Zhao, Yu,Henthorn, Hillary A.,Pluth, Michael D.
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supporting information
p. 16365 - 16376
(2017/11/22)
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- Esterase activated carbonyl sulfide/hydrogen sulfide (H2S) donors
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Hydrogen sulfide (H2S) is a mediator of a number of cellular processes, and modulating cellular levels of this gas has emerged as an important therapeutic area. Localized generation of H2S is thus very useful but highly challenging. Here, we report pivaloyloxymethyl-based carbonothioates and carbamothioates that are activated by the enzyme, esterase, to generate carbonyl sulfide (COS), which is hydrolyzed to H2S.
- Chauhan, Preeti,Bora, Prerona,Ravikumar, Govindan,Jos, Swetha,Chakrapani, Harinath
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supporting information
p. 62 - 65
(2017/11/28)
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- Thermal Decomposition Mechanism for Ethanethiol
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The thermal decomposition of ethanethiol was studied using a 1 mm x 2 cm pulsed silicon carbide microtubular reactor, CH3CH2SH + Δ → Products. Unlike previous studies these experiments were able to identify the initial ethanethiol decomposition products. Ethanethiol was entrained in either an Ar or a He carrier gas, passed through a heated (300-1700 K) SiC microtubular reactor (roughly ≤100 μs residence time) and exited into a vacuum chamber. Within one reactor diameter the gas cools to less than 50 K rotationally, and all reactions cease. The resultant molecular beam was probed by photoionization mass spectroscopy and IR spectroscopy. Ethanethiol was found to undergo unimolecular decomposition by three pathways: CH3CH2SH → (1) CH3CH2 + SH, (2) CH3 + H2C=S, and (3) H2C=CH2 + H2S. The experimental findings are in good agreement with electronic structure calculations. (Chemical Equation Presented).
- Vasiliou, AnGayle K.,Anderson, Daniel E.,Cowell, Thomas W.,Kong, Jessica,Melhado, William F.,Phillips, Margaret D.,Whitman, Jared C.
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p. 4953 - 4960
(2017/07/17)
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- Catalytic reactions of dimethyl disulfide with thiophene and benzene
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The gas-phase reaction of dimethyl disulfide with thiophene proceeds under the action of acid catalysts under atmospheric pressure at 160-350°C and a residence time of τ = 0.6-21 s to form thioalkylation and alkylation products. Dimethyl disulfide reacts with benzene to form only alkylation products. Catalysts containing both strong protic and Lewis acid sites, as well as basic sites of moderate strength, are the most active ones.
- Mashkina,Khairulina
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- Synthesis and Pharmacological Evaluation of Novel Adenine-Hydrogen Sulfide Slow Release Hybrids Designed as Multitarget Cardioprotective Agents
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This work deals with the design, synthesis, and evaluation of the cardioprotective properties of a number of novel hybrid compounds combining the adenine nucleus with a suitable H2S slow-releasing moiety, coupled via a stable ether bond. The H2S release rate of the hybrids and their ability to increase cGMP were estimated in vitro. The most promising derivatives 4 and 11, both containing 4-hydroxythiobenzamide moiety as H2S donor, were selected for further in vivo evaluation. Their ability to release H2S in vivo was recorded using a new fully validated UPLC-DAD method. Both compounds reduced significantly the infarct size when administered at the end of sustained ischemia. Mechanistic studies showed that they conferred enhanced cardioprotection compared to adenine or 4-hydroxythiobenzamide. They activate the PKG/PLN pathway in the ischemic myocardium, suggesting that the combination of both pharmacophores results in synergistic cardioprotective activity through the combination of both molecular pathways that trigger cardioprotection.
- Lougiakis, Nikolaos,Papapetropoulos, Andreas,Gikas, Evangelos,Toumpas, Spyridon,Efentakis, Panagiotis,Wedmann, Rudolf,Zoga, Anastasia,Zhou, Zhongmin,Iliodromitis, Efstathios K.,Skaltsounis, Alexios-Leandros,Filipovic, Milos R.,Pouli, Nicole,Marakos, Panagiotis,Andreadou, Ioanna
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p. 1776 - 1790
(2016/03/22)
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- CdS nanocapsules and nanospheres as efficient solar light-driven photocatalysts for degradation of Congo red dye
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CdS-1 (nanosphers) and CdS-2 (nanocapsule), were synthesized via green synthetic route without using any toxic surfactants by thermolysis of bis(4-benzhydrylpiperazine-1-carbodithioate-κ2 S, S?)cadmium(II) (1) and bis (4-benzylpipera-zine-1-carbodithioate-κ2 S, S?)cadmium(II) (2), respectively in the presence of ethylenediamine as a solvent. The nanoparticles were characterized by TEM, XRD, SEM, FT-IR UV–Visible and Fluorescence spectroscopy. The TEM results showed the formation of nanospheres (CdS-1) and nanocapsules (CdS-2) from complexes 1 and 2, respectively. Both CdS nanoparticles (NPs) have hexagonal crystal phase and a band gap value in the visible region as confirmed by the XRD and UV–Visible spectra, respectively. The photoluminescence (PL) data revealed that CdS-2 has longer recombination time of photo-injected electron hole pairs than CdS-1. The similar FT-IR spectra for both CdS NPs, and different HOMO-LUMO gap values for complexes {4.8187?eV (1) and CdS-2 4.7504?eV (2)} as predicted by DFT calculations suggest that stability of complexes play a key role in controlling morphology. Furthermore, the visible light driven photocatalytic degradation of Congo red dye was observed higher for nanocapsules than nanospheres due to a longer recombination time of photo-injected electron hole pairs.
- Khan, Azam,Zia-ur-Rehman,Rehman, Muneeb-ur-,Khan, Rajwali,Zulfiqar,Waseem, Amir,Iqbal, Azhar,Shah, Zawar Hussain
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- Ammonium tetrathiomolybdate as a water-soluble and slow-release hydrogen sulfide donor
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Ammonium tetrathiomolybdate (TTM) was found to be a slow hydrogen sulfide (H2S) releasing agent. Its H2S generation capability in aqueous solutions was confirmed by UV–vis and fluorescence assays. TTM also showed H2S-like cytoprotective effects in hydrogen peroxide (H2O2)-induced oxidative damage in HaCaT cells.
- Xu, Shi,Yang, Chun-Tao,Meng, Fu-Hui,Pacheco, Armando,Chen, Li,Xian, Ming
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supporting information
p. 1585 - 1588
(2016/07/27)
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- Controlled chemical release of hydrogen sulfide
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Agents of formula: where R1 and R2 vary independently and are acyl, sulfonyl, phosphoryl, alkyl, substituted alkyl, halogen, aryl, arylalkyl, substituted aryl, heteroaryl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, heterocycle, or heteroatoms; and R3 is H or a member of a ring structure which includes R2, are provided; as are agents of formula: where R1, R2 and R3 vary independently and: R1=OH, OR′, NHR′, NR′R″ (with R′ R″=alkyl, aryl, heteroaryl, etc); R2=acyl, alkyl, aryl, sulfonyl, etc; R3=alkyl, aryl, substituted aryl, heteroaryl, etc; and R4 and R5 are (independently) H, methyl or alkyl, substituted alkyl, aryl, substituted aryl, etc. Methods of using the agents to treat e.g. cardiovascular disease, stroke, shock, injuries caused by hypoxia, male erectile dysfunction, and Alzheimer's are provided.
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Page/Page column 24; 25; 26
(2015/09/22)
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- Design, Synthesis, and Cardioprotective Effects of N-Mercapto-Based Hydrogen Sulfide Donors
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Hydrogen sulfide (H2S) is a signaling molecule which plays regulatory roles in many physiological and/or pathological processes. Therefore, regulation of H2S levels could have great potential therapeutic value. In this work, we report the design, synthesis, and evaluation of a class of N-mercapto (N-SH)-based H2S donors. Thirty-three donors were synthesized and tested. Our results indicated that controllable H2S release from these donors could be achieved upon structural modifications. Selected donors (NSHD-1, NSHD-2, and NSHD-6) were tested in cellular models of oxidative damage and showed significant cytoprotective effects. Moreover, NSHD-1 and NSHD-2 were also found to exhibit potent protective effects in a murine model of myocardial ischemia reperfusion (MI/R) injury.
- Zhao, Yu,Yang, Chuntao,Organ, Chelsea,Li, Zhen,Bhushan, Shashi,Otsuka, Hiro,Pacheco, Armando,Kang, Jianming,Aguilar, Hector C.,Lefer, David J.,Xian, Ming
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p. 7501 - 7511
(2015/10/05)
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