Glutathione-triggered prodrugs: Design strategies, potential applications, and perspectives

The burgeoning prodrug strategy offers a promising avenue toward improving the efficacy and specificity of cytotoxic drugs. Elevated intracellular levels of glutathione (GSH) have been regarded as a hallmark of tumor cells and characteristic feature of the tumor microenvironment. Considering the pivotal involvement of elevated GSH in the tumorigenic process, a diverse repertoire of GSH-triggered prodrugs has been developed for cancer therapy, facilitating the attenuation of deleterious side effects associated with conventional chemotherapeutic agents and/or the attainment of more efficacious therapeutic outcomes. These prodrug formulations encompass a spectrum of architectures, spanning from small molecules to polymer-based and organic-inorganic nanomaterial constructs. Although the GSH-triggered prodrugs have been gaining increasing interests, a comprehensive review of the advancements made in the field is still lacking. To fill the existing lacuna, this review undertakes a retrospective analysis of noteworthy research endeavors, based on a categorization of these molecules by their diverse recognition units (i.e., disulfides, diselenides, Michael acceptors, and sulfonamides/sulfonates). This review also focuses on explaining the distinct benefits of employing various chemical architecture strategies in the design of these prodrug agents. Furthermore, we highlight the potential for synergistic functionality by incorporating multiple-targeting conjugates, theranostic entities, and combinational treatment modalities, all of which rely on the GSH-triggering. Overall, an extensive overview of the emerging field is presented in this review, highlighting the obstacles and opportunities that lie ahead. Our overarching goal is to furnish methodological guidance for the development of more efficacious GSH-triggered prodrugs in the future. By assessing the pros and cons of current GSH-triggered prodrugs, we expect that this review will be a handful reference for prodrug design, and would provide a guidance for improving the properties of prodrugs and discovering novel trigger scaffolds for constructing GSH-triggered prodrugs.

Sulfonate-Containing Polyelectrolytes for Perovskite Modification: Chemical Configuration, Property, and Performance

Three sulfonate-containing polyelectrolytes are elaborately designed and used to passivate perovskite film with the anti-solvent method. Under the influence of the secondary monomer, three copolymers present various chemical configurations and deliver different modification effects. Fluorene-thiophene copolymer STF has linear and highly-conjugated chain. STF-perovskite film presents large crystal grains. Fluorene-carbazole copolymer SCF has flexible chain and easily enters into grain boundary areas. SCF-perovskite film is homogenous and continuous. Fluorene-fluorene copolymer SPF agglomerates on the surface and is not applicable to the anti-solvent method. The full investigation demonstrates that STF and SCF not only conduct surface defect passivation, but also improve the film quality by being involved in the perovskite's crystallization process. Compared with the control device, the devices with STF and SCF deliver high efficiency and excellent stability. The unencapsulated devices with STF and SCT maintain ≈80% of the initial power conversion efficiency (PCE) after 40 days of storage under 30-40% relative humidity. SCF performs better and the device maintains 60% of the initial PCE after 20 days of storage under 60-80% relative humidity.

New Water-Soluble (Iminomethyl)benzenesulfonates Derived from Biogenic Amines for Potential Biological Applications

In this paper, a highly efficient and straightforward method for synthesizing novel Schiff bases was developed by reacting selected biogenic amines with sodium 2-formylbenzene sulfonate and sodium 3-formylbenzene sulfonate. 1H and 13C NMR, IR spectroscopy, and high-resolution mass spectrometry were used to characterize the new compounds. The main advantages of the proposed procedure include simple reagents and reactions carried out in water or methanol and at room temperature, which reduces time and energy. Moreover, it was shown that the obtained water-soluble Schiff bases are stable in aqueous solution for at least seven days. Additionally, the antioxidant and antimicrobial activity of synthesized Schiff bases were tested.

Isethionate is an intermediate in the degradation of sulfoacetate by the human gut pathobiont Bilophila wadsworthia

The obligately anaerobic sulfite-reducing bacterium Bilophila wadsworthia is a common human pathobiont inhabiting the distal intestinal tract. It has a unique ability to utilize a diverse range of food- and host-derived sulfonates to generate sulfite as a terminal electron acceptor (TEA) for anaerobic respiration, converting the sulfonate sulfur to H2S, implicated in inflammatory conditions and colon cancer. The biochemical pathways involved in the metabolism of the C2 sulfonates isethionate and taurine by B. wadsworthia were recently reported. However, its mechanism for metabolizing sulfoacetate, another prevalent C2 sulfonate, remained unknown. Here, we report bioinformatics investigations and in vitro biochemical assays that uncover the molecular basis for the utilization of sulfoacetate as a source of TEA (STEA) for B. wadsworthia, involving conversion to sulfoacetyl-CoA by an ADP-forming sulfoacetate-CoA ligase (SauCD), and stepwise reduction to isethionate by NAD(P)H-dependent enzymes sulfoacetaldehyde dehydrogenase (SauS) and sulfoacetaldehyde reductase (TauF). Isethionate is then cleaved by the O2-sensitive isethionate sulfolyase (IseG), releasing sulfite for dissimilatory reduction to H2S. Sulfoacetate in different environments originates from anthropogenic sources such as detergents, and natural sources such as bacterial metabolism of the highly abundant organosulfonates sulfoquinovose and taurine. Identification of enzymes for anaerobic degradation of this relatively inert and electron-deficient C2 sulfonate provides further insights into sulfur recycling in the anaerobic biosphere, including the human gut microbiome.

Structure and mechanism of sulfofructose transaldolase, a key enzyme in sulfoquinovose metabolism

Sulfoquinovose (SQ) is a key component of plant sulfolipids (sulfoquinovosyl diacylglycerols) and a major environmental reservoir of biological sulfur. Breakdown of SQ is achieved by bacteria through the pathways of sulfoglycolysis. The sulfoglycolytic sulfofructose transaldolase (sulfo-SFT) pathway is used by gut-resident firmicutes and soil saprophytes. After isomerization of SQ to sulfofructose (SF), the namesake enzyme catalyzes the transaldol reaction of SF transferring dihydroxyacetone to 3C/4C acceptors to give sulfolactaldehyde and fructose-6-phosphate or sedoheptulose-7-phosphate. We report the 3D cryo-EM structure of SF transaldolase from Bacillus megaterium in apo and ligand bound forms, revealing a decameric structure formed from two pentameric rings of the protomer. We demonstrate a covalent "Schiff base" intermediate formed by reaction of SF with Lys89 within a conserved Asp-Lys-Glu catalytic triad and defined by an Arg-Trp-Arg sulfonate recognition triad. The structural characterization of the signature enzyme of the sulfo-SFT pathway provides key insights into molecular recognition of the sulfonate group of sulfosugars.

Design, Synthesis and Bioactivity of Novel Pyrimidine Sulfonate Esters Containing Thioether Moiety

Pesticides play an important role in crop disease and pest control. However, their irrational use leads to the emergence of drug resistance. Therefore, it is necessary to search for new pesticide-lead compounds with new structures. We designed and synthesized 33 novel pyrimidine derivatives containing sulfonate groups and evaluated their antibacterial and insecticidal activities. Results: Most of the synthesized compounds showed good antibacterial activity against Xanthomonas oryzae pv. Oryzae (Xoo), Xanthomonas axonopodis pv. Citri (Xac), Pseudomonas syringae pv. actinidiae (Psa) and Ralstonia solanacearum (Rs), and certain insecticidal activity. A₅, A₃₁ and A₃₃ showed strong antibacterial activity against Xoo, with EC₅₀ values of 4.24, 6.77 and 9.35 μg/mL, respectively. Compounds A₁, A₃, A₅ and A₃₃ showed remarkable activity against Xac (EC₅₀ was 79.02, 82.28, 70.80 and 44.11 μg/mL, respectively). In addition, A₅ could significantly improve the defense enzyme (superoxide dismutase, peroxidase, phenylalanine ammonia-lyase and catalase) activity of plants against pathogens and thus improve the disease resistance of plants. Moreover, a few compounds also showed good insecticidal activity against Plutella xylostella and Myzus persicae. The results of this study provide insight into the development of new broad-spectrum pesticides.

The Nanostructure of Alkyl-Sulfonate Ionic Liquids: Two 1-Alkyl-3-methylimidazolium Alkyl-Sulfonate Homologous Series

The functionalization of polymers with sulfonate groups has many important uses, ranging from biomedical applications to detergency properties used in oil-recovery processes. In this work, several ionic liquids (ILs) combining 1-alkyl-3-methylimidazolium cations [C_nC₁im]⁺ (4 ≤ n ≤ 8) with alkyl-sulfonate anions [C_mSO₃]^- (4 ≤ m ≤ 8) have been studied using molecular dynamics simulations, totalizing nine ionic liquids belonging to two homologous series. The radial distribution functions, structure factors, aggregation analyses, and spatial distribution functions reveal that the increase in aliphatic chain length induces no significant change in the structure of the polar network of the ILs. However, for imidazolium cations and sulfonate anions with shorter alkyl chains, the nonpolar organization is conditioned by the forces acting on the polar domains, namely, electrostatic interactions and hydrogen bonding.

Plasma and Skin Per- and Polyfluoroalkyl Substance (PFAS) Levels in Dairy Cattle with Lifetime Exposures to PFAS-Contaminated Drinking Water and Feed

Plasma and ear notch samples were removed from 164 Holstein cows and heifers, which had lifetime exposures to per- and polyfluoroalkyl substances (PFAS) through consumption of contaminated feed and water sources. A suite of nine PFAS including five perfluoroalkyl carboxylic acids (PFCA) and four perfluoroalkyl sulfonic acids (PFSA) was quantified in plasma and ear notch samples by liquid chromatography-mass spectrometry. Bioaccumulation of four- to nine-carbon PFCAs did not occur in plasma or skin, but PFSAs longer than four carbons accumulated in both plasma and skin. Exposure periods of at least 1 year were necessary for PFSAs to reach steady-state concentrations in plasma. Neither parity (P = 0.76) nor lactation status (P = 0.30) affected total PFSA concentrations in mature cow plasma. In contrast, lactation status greatly affected (P < 0.0001) total PFSA concentrations in ear notch samples. Skin samples could be used for biomonitoring purposes in instances when on-farm blood collection and plasma preparation are not practical.

The pathway for coenzyme M biosynthesis in bacteria

Mercaptoethane sulfonate or coenzyme M (CoM) is the smallest known organic cofactor and is most commonly associated with the methane-forming step in all methanogenic archaea but is also associated with the anaerobic oxidation of methane to CO₂ in anaerobic methanotrophic archaea and the oxidation of short-chain alkanes in Syntrophoarchaeum species. It has also been found in a small number of bacteria capable of the metabolism of small organics. Although many of the steps for CoM biosynthesis in methanogenic archaea have been elucidated, a complete pathway for the biosynthesis of CoM in archaea or bacteria has not been reported. Here, we present the complete CoM biosynthesis pathway in bacteria, revealing distinct chemical steps relative to CoM biosynthesis in methanogenic archaea. The existence of different pathways represents a profound instance of convergent evolution. The five-step pathway involves the addition of sulfite, the elimination of phosphate, decarboxylation, thiolation, and the reduction to affect the sequential conversion of phosphoenolpyruvate to CoM. The salient features of the pathway demonstrate reactivities for members of large aspartase/fumarase and pyridoxal 5'-phosphate-dependent enzyme families.

Biochemical Investigation of 3-Sulfopropionaldehyde Reductase HpfD

Sulfoquinovose is the polar headgroup of plant sulfolipids and is a globally abundant organosulfur compound, and its degradation by bacteria is an important component of the sulfur cycle. Sulfoquinovose degradation by certain bacteria, including Escherichia coli, produces dihydroxypropanesulfonate (DHPS), which is further converted by anaerobic bacteria into 3-hydroxypropanesulfonate (3-HPS), through the catalytic action of DHPS dehydratase (a member of the glycyl radical enzyme family), and sulfopropionaldehyde reductase HpfD (a member of the metal-dependent alcohol dehydrogenase family). Here we report biochemical investigation of Hungatella hathewayi HpfD. In addition to 3-HPS, HpfD also displayed high catalytic activities for NAD⁺ -dependent oxidation of 4-hydroxybutanesulfonate (4-HBS) and γ-hydroxybutyrate (GHB). The highest activity was obtained with Fe²⁺ or Mn²⁺ as the divalent metal cofactor. Bioinformatics studies suggest that, in addition to DHPS degradation, 3-HPS and γ-aminobutyrate (GABA) degradations also involve HpfD homologs.

Lignosulfonic Acid Sodium Is a Noncompetitive Inhibitor of Human Factor XIa

The anticoagulant activity of lignosulfonic acid sodium (LSAS), a non-saccharide heparin mimetic, was investigated in this study. LSAS is a relatively safe industrial byproduct with similar polyanionic characteristics to that of heparin. Human plasma clotting assays, fibrin polymerization testing, and enzyme inhibition assays were exploited to investigate the anticoagulant activity of LSAS. In normal human plasma, LSAS selectively doubled the activated partial thromboplastin time (APTT) at ~308 µg/mL. Equally, LSAS doubled APTT at ~275 µg/mL in antithrombin-deficient plasma. Yet, LSAS doubled APTT at a higher concentration of 429 µg/mL using factor XI-deficient plasma. LSAS did not affect FXIIIa-mediated fibrin polymerization at 1000 µg/mL. Enzyme assays revealed that LSAS inhibits factor XIa (FXIa) with an IC₅₀ value of ~8 μg/mL. LSAS did not inhibit thrombin, factor IXa, factor Xa, factor XIIIa, chymotrypsin, or trypsin at the highest concentrations tested and demonstrated significant selectivity against factor XIIa and plasmin. In Michaelis–Menten kinetics, LSAS decreased the V_MAX of FXIa hydrolysis of a tripeptide chromogenic substrate without significantly changing its K_M indicating an allosteric inhibition mechanism. The inhibitor also disrupted the generation of FXIa–antithrombin complex, inhibited factor XIIa-mediated and thrombin-mediated activation of the zymogen factor XI to FXIa, and competed with heparin for binding to FXIa. Its action appears to be reversed by protamine sulfate. Structure–activity relationship studies demonstrated the advantageous selectivity and allosteric behavior of LSAS over the acetylated and desulfonated derivatives of LSAS. LSAS is a sulfonated heparin mimetic that demonstrates significant anticoagulant activity in human plasma. Overall, it appears that LSAS is a potent, selective, and allosteric inhibitor of FXIa with significant anticoagulant activity in human plasma. Altogether, this study introduces LSAS as a promising lead for further development as an anticoagulant.

Benzenedisulfonic Acid as an ALD/MLD Building Block for Crystalline Metal-Organic Thin Films*

Two new atomic/molecular layer deposition processes for depositing crystalline metal-organic thin films, built from 1,4-benzenedisulfonate (BDS) as the organic linker and Cu or Li as the metal node, are reported. The processes yield in-situ crystalline but hydrated Cu-BDS and Li-BDS films; in the former case, the crystal structure is of a previously known metal-organic-framework-like structure, while in the latter case not known from previous studies. Both hydrated materials can be readily dried to obtain the crystalline unhydrated phases. The stability and the ionic conductivity of the unhydrated Li-BDS films were characterized to assess their applicability as a thin film solid polymer Li-ion conductor.

Discovery of Novel Sultone Fused Berberine Derivatives as Promising Tdp1 Inhibitors

A new type of berberine derivatives was obtained by the reaction of berberrubine with aliphatic sulfonyl chlorides. The new polycyclic compounds have a sultone ring condensed to C and D rings of a protoberberine core. The reaction conditions were developed to facilitate the formation of sultones with high yields without by-product formation. Thus, it was shown that the order of addition of reagents affects the composition of the reaction products: when sulfochlorides are added to berberrubine, their corresponding 9-O-sulfonates are predominantly formed; when berberrubine is added to pre-generated sulfenes, sultones are the only products. The reaction was shown to proceed stereo-selectively and the cycle configuration was confirmed by 2D NMR spectroscopy. The inhibitory activity of the synthesized sultones and their 12-brominated analogs against the DNA-repair enzyme tyrosyl-DNA phosphodiesterase 1 (Tdp1), an important target for a potential antitumor therapy, was studied. All derivatives were active in the micromolar and submicromolar range, in contrast to the acyclic analogs and 9-O-sulfonates, which were inactive. The significance of the sultone cycle and bromine substituent in binding with the enzyme was confirmed using molecular modeling. The active inhibitors are mostly non-toxic to the HeLa cancer cell line, and several ligands show synergy with topotecan, a topoisomerase 1 poison in clinical use. Thus, novel berberine derivatives can be considered as candidates for adjuvant therapy against cancer.

Microwave-Assisted Synthesis of Organometallic Rhenium (I) Pentylcarbonato Complexes: New Synthon for Carboxylato, Sulfonato and Chlorido Complexes

Tricarbonylrhenium(I)(α-diimine) complexes are of importance because of their strong cytotoxic and fluorescence properties. Syntheses of such complexes were achieved through a two-step process. First, the pentylcarbonato complexes, fac-(CO)₃(α-diimine)ReOC(O)OC₅H₁₁ were synthesized through a microwave-assisted reaction of Re₂(CO)₁₀, α-diimine, 1-pentanol and CO₂ in a few hours. Second, the pentylcarbonato complexes are treated with carboxylic, sulfonic and halo acids to obtain the corresponding carboxylato, sulfonato and halido complexes. This is the first example of conversion of Re₂(CO)₁₀ into a rhenium carbonyl complex through microwave-assisted reaction.

Anion Texturing Towards Dendrite-Free Zn Anode for Aqueous Rechargeable Batteries

The reversibility of metal anode is a fundamental challenge to the lifetime of rechargeable batteries. Though being widely employed in aqueous energy storage systems, metallic zinc suffers from dendrite formation that severely hinders its applications. Here we report texturing Zn as an effective way to address the issue of zinc dendrite. An in-plane oriented Zn texture with preferentially exposed (002) basal plane is demonstrated via a sulfonate anion-induced electrodeposition, noting no solid report on (002) textured Zn till now. Anion-induced reconstruction of zinc coordination is revealed to be responsible for the texture formation. Benchmarking against its (101) textured-counterpart by the conventional sulphate-based electrolyte, the Zn (002) texture enables highly reversible stripping/plating at a high current density of 10 mA cm^-2 , showing its dendrite-free characteristics. The Zn (002) texture-based aqueous zinc battery exhibits excellent cycling stability. The developed anion texturing approach provides a pathway towards exploring zinc chemistry and prospering aqueous rechargeable batteries.

Synthesis and insecticidal activity of sulfonate derivatives of sesamol against Mythimna separata in vivo

A series of sulfonate derivatives of sesamol were synthesized and evaluated for their insecticidal activity against a crop-threatening agricultural pest, the pre-third-instar larvae of Mythimna separata in vivo. Among all the target compounds, compounds 3b, 3g, 3h, and 3p exhibited more promising insecticidal activity than sesamol and toosendanin, and the final mortality rates (FMRs) of 3b, 3g, 3h, 3p, 1, and toosendanin were 60.7%/60.7%/67.9%/53.6%/32.1%/50.0%, respectively. Especially compound 3h exhibited the most potent insecticidal activity with FMRs of 67.9%. This suggested that a 4-fluorophenylsulfonyl group introduced at the hydroxyl position of sesamol was necessary for obtaining the most potent compound.[Formula: see text].

Synthesis of sulfonate derivatives of maltol and their biological activity against Phytophthora capsici and Bursaphelenchus xylophilus in vitro

Sixteen sulfonate derivatives of maltol were synthesized and screened in vitro for their anti-oomycete and nematicidal activity against Phytophthora capsici and Bursaphelenchus xylophilus, respectively. Among all the compounds, 3e, 3m, and 3p exhibited the most promising and pronounced anti-oomycete activity against P. capsici than zoxamide, and the EC₅₀ values of 25.42, 18.44, 23.69, and 27.99 mg/L, respectively; compounds 3e, 3m, 3n, and 3p exhibited potent nematicidal activity with LC₅₀ values ranging from 1 to 2 mg/L, especially 3m and 3n showed the best promising and pronounced nematicidal activity, with LC₅₀ values of 1.1762 and 1.2384 mg/L, respectively. [Formula: see text].

Design, Synthesis, Acaricidal Activities, and Structure-Activity Relationship Studies of Novel Oxazolines Containing Sulfonate Moieties

With the ultimate goal of addressing pest-related constraints on global agricultural production, we used combination principles to design and synthesize 2,4-diphenyl-1,3-oxazolines containing a sulfonate moiety at the para-position of the 4-phenyl group. The target compounds, which have strong affinity for lipids and can be expected to traverse cell membranes, were characterized by ¹H and ¹³C NMR spectroscopy and high-resolution mass spectrometry. Their activities against the larvae and eggs of carmine spider mites (Tetranychus cinnabarinus) were determined by a leaf-dipping method and compared with the activity of the commercial acaricide etoxazole. Most of the test compounds displayed good ovicidal and larvicidal activities. In particular, a tert-butylphenyl-substituent compound possessed better larvicidal activity (LC₅₀ = 0.022 ± 0.009 mg/L) and ovicidal activity (0.044 ± 0.020 mg/L) than etoxazole (0.091 ± 0.051 and 0.095 ± 0.059 mg/L, respectively). Given its outstanding bioactivities, this compound deserves further attention as a pesticide candidate.

In Vitro and In Vivo Inhibition of the Infectivity of Human Enterovirus 71 by a Sulfonated Food Azo Dye, Brilliant Black BN

Hand, foot, and mouth disease (HFMD), a highly contagious disease in children, is caused by human enteroviruses, including enterovirus 71 (EV71), coxsackievirus A16 (CVA16), and coxsackievirus A6 (CVA6). Although HFMD is usually mild and self-limiting, EV71 infection occasionally leads to fatal neurological disorders. Currently, no commercial antiviral drugs for HFMD treatment are available. Here, numerous sulfonated azo dyes, widely used as food additives, were identified as having potent antiviral activities against human enteroviruses. Among them, brilliant black BN (E151) was able to inhibit all EV71, CVA16, and CVA6 strains tested. In rhabdomyosarcoma cells, the 50% inhibitory concentrations of the dye E151 for various strains of EV71 ranged from 2.39 μM to 28.12 μM, whereas its 50% cytotoxic concentration was 1,870 μM. Food azo dyes, including E151, interacted with the vertex of the 5-fold axis of EV71 and prevented viral entry. Their efficacy in viral inhibition was regulated by amino acids at VP1-98, VP1-145, and/or VP1-246. Dye E151 not only prevented EV71 attachment but also eluted attached viruses in a concentration-dependent manner. Moreover, E151 inhibited the interaction between EV71 and its cellular uncoating factor cyclophilin A. In vivo studies demonstrated that E151 at a dose of 200 mg/kg of body weight/day given on the initial 4 days of challenge protected AG129 mice challenged with 10× the 50% lethal dose of wild-type EV71 isolates. Taken together, these data highlight E151 as a promising antiviral agent against EV71 infection.IMPORTANCE Human enterovirus 71 (EV71) is one of the causative agents of hand, foot, and mouth disease in children and is responsible for thousands of deaths in the past 20 years. Food azo dyes have been widely used since the nineteenth century; however, their biological effects on humans and microbes residing in humans are poorly understood. Here, we discovered that one of these dyes, brilliant black BN (E151), was particularly effective in inhibiting the infectivity of EV71 in both cell culture and mouse model studies. Mechanistic studies demonstrated that these sulfonated dyes mainly competed with EV71 attachment factors for viral binding to block viral attachment/entry to host cells. As no commercial antiviral drugs against EV71 are currently available, our findings open an avenue to exploit the development of permitted food dye E151 as a potential anti-EV71 agent.

Facilitating Proton Transport in Nafion-Based Membranes at Low Humidity by Incorporating Multifunctional Graphene Oxide Nanosheets

Nafion, as a state-of-the-art solid electrolyte for proton exchange membrane fuel cells (PEMFCs), suffers from drastic decline in proton conductivity with decreasing humidity, which significantly restricts the efficient and stable operation of the fuel cell system. In this study, the proton conductivity of Nafion at low relative humidity (RH) was remarkably enhanced by incorporating multifunctional graphene oxide (GO) nanosheets as multifunctional fillers. Through surface-initiated atom transfer radical polymerization of sulfopropyl methacrylate (SPM) and poly(ethylene glycol) methyl ether methacrylate, the copolymer-grafted GO was synthesized and incorporated into the Nafion matrix, generating efficient paths at the Nafion-GO interface for proton conduction. The Lewis basic oxygen atoms of ethylene oxide (EO) units and sulfonated acid groups of SPM monomers served as additional proton binding and release sites to facilitate the proton hopping through the membrane. Meanwhile, the hygroscopic EO units enhanced the water retention property of the composite membrane, conferring a dramatic increase in proton conductivity under low humidity. With 1 wt % filler loading, the composite membrane displayed the highest proton conductivity of 2.98 × 10^-2 S cm^-1 at 80 °C and 40% RH, which was 10 times higher than that of recast Nafion. Meanwhile, the Nafion composite exhibited a 135.5% increase in peak power density at 60 °C and 50% RH, indicating its great application potential in PEMFCs.

Crystal structure of phenyl 2,4,5-tri-chloro-benzene-sulfonate

The title compound, C12H7Cl3O3S, was synthesized via a nucleophilic substitution reaction between phenol and 2,4,5-tri-chloro-benzene-sulfonyl chloride. The two aryl rings are oriented gauche to one another around the sulfonate S-O bond, with a C-S-O-C torsion angle of -70.68 (16)°, and the two rings are inclined to one another by 72.40 (7)°. In the crystal, mol-ecules are linked via various C-Cl⋯π inter-actions, forming ribbons propagating along [100]. Neighboring ribbons are linked by a weak C-Cl⋯π inter-action, forming layers parallel to (010).

Synthesis and Evaluation of Aminothiazole-Paeonol Derivatives as Potential Anticancer Agents

In this study, novel aminothiazole-paeonol derivatives were synthesized and characterized using ¹H-NMR, ¹³C-NMR, IR, mass spectroscopy, and high performance liquid chromatography. All the new synthesized compounds were evaluated according to their anticancer effect on seven cancer cell lines. The experimental results indicated that these compounds possess high anticancer potential regarding human gastric adenocarcinoma (AGS cells) and human colorectal adenocarcinoma (HT-29 cells). Among these compounds, N-[4-(2-hydroxy-4-methoxyphenyl)thiazol-2-yl]-4-methoxybenzenesulfonamide (13c) had the most potent inhibitory activity, with IC₅₀ values of 4.0 µM to AGS, 4.4 µM to HT-29 cells and 5.8 µM to HeLa cells. The 4-fluoro-N-[4-(2-hydroxy-4-methoxyphenyl)thiazol-2-yl]benzenesulfonamide (13d) was the second potent compound, showing IC₅₀ values of 7.2, 11.2 and 13.8 µM to AGS , HT-29 and HeLa cells, respectively. These compounds are superior to 5-fluorouracil (5-FU) for relatively higher potency against AGS and HT-29 human cancer cell lines along with lower cytotoxicity to fibroblasts. Novel aminothiazole-paeonol derivatives in this work might be a series of promising lead compounds to develop anticancer agents for treating gastrointestinal adenocarcinoma.

Crystal structure of (R)-2'-benz-yloxy-[1,1'-binaphthalen]-2-yl tri-fluoro-methane-sulfonate

In the title compound, C₂₈H₁₉F₃O₄S, a new 2′-benz­yloxy (R)-BINOL derivative containing a tri­fluoro­methane­sulfonate group in the 2-position, the planes of the two naphthyl ring systems (r.m.s. deviations = 0.012 and 0.019 Å) are at an angle of 73.36 (2)°, and the planes of the benzyl ring and the naphthyl ring system bound to the ether O atom are at an angle of 75.67 (4)°. In the crystal, mol­ecules are linked via C—H⋯F hydrogen bonds, forming chains propagating along [100]. The chains are linked via a weak C—F⋯π inter­action and weak π–π inter­actions [shortest inter-centroid distance = 3.9158 (12) Å], forming a three-dimensional structure. The absolute structure of the mol­ecule in the crystal was determined by resonant scattering [Flack parameter = 0.02 (6)].