Complexes Cu(II)(4'-R-terpyridine)2(ClO4)2[R=2-thienyl(1), 2-(5-bromothienyl)(2), 2-(5-methyl-thienyl)(3) and 2-(5-methoxythienyl)(4)] were synthesized, and their structures were determined by single-crystal X-ray diffraction analyses and were further characterized by high resolution mass spectrometry, infrared spectroscopy(IR), as well as elemental analysis. Single crystal X-ray diffraction analysis shows that Cu(II) ions in the complexes are both six-coordinated with N6 coordination sphere, displaying distorted octahedral geometries. In addition, the UV-Vis absorption spectra show that the four complexes all exhibit absorption components in both UV and visible light regions. Thus, the photocatalytic activities of the four complexes in the degradation of organic dyes were investigated.
A novel polyoxometalate-based hybrid modified by 3d-4d/2-ptz heterometallic organic chains[n-ptz=5-(n-pyridyl)-tetrazolate], Ag2[Cu(2-ptz)2][β-Mo8O26]0.5·H2O(1)[2-ptz=5-(2-pyridyl)-tetrazolate], was synthesized under hydrothermal conditions. The 3D framework structure of compound 1 was constructed from 1D novel 3d-4d heterometallic organic chains[CuAg2(2-ptz)2]2+ as cationic complexes and[β-Mo8O26]4- polyoxoanions via Cu-O and Ag-O bonds, in which each[β-Mo8O26]4- polyoxoanion was surrounded by six such chains. The electrochemical and photocatalytic properties of compound 1 were investigated.
Hydrophilic acid-resistant Ge-ZSM-5 membranes were synthesized via secondary growth method on porous α-Al2O3 substrates with Silicalite-1 zeolite as seeds. The membranes were characterized by means of scanning electron microscopy, X-ray diffraction and energy dispersive X-ray spectrometer to look into the microstructures and element contents of the membranes. The separation performance of the membranes was investigated for separating water from acetic acid solution by pervaporation. The results show that membranes fabricated by the conventional secondary growth method have a high flux, but the selectivity of them is rather limited. Preheating the secondary synthesis sol and using the supernatant as the secondary synthesis sol for membrane fabrication were found to be effective to lower the concentration of the nutrient to constrain re-nucleation, at the same time, lower the Al content in the membranes. The membrane obtained exhibited improved separation performance with a separation factor of 83 at a flux of 0.67 kg·m-2·h-1 at 353 K for a feed concentration of 98% acetic acid solution.
In an LC-MS investigation of drug metabolic samples from the traditional Chinese medicine Chaihu, the baseline was established via MS selectivity-based chromatogram baseline-shift elimination and exogenous metabolite signals were obtained with MS-based orthogonal projection. Their respective influences on the metabolic chromatographic profiles, metabonomics model and evaluation of drug toxicity were investigated. The baseline shift enhanced the difference between the metabolic profiles of the control and Chaihu groups, and the corresponding correlation coefficient decreased from 70.38% to 62.69%. The exogenous metabolite signal led to a biased expression of the evaluated toxicity, and the enhanced expression resulted in an average Mahalanobis distance of approximately 9.4%. Based on established metabonomics models, the results show that Chaihu induces liver toxicity at a lower dose of 25 g/kg, twice a day. At this dose, Chaihu elicits a process of self-repair for its liver toxicity. The signal intensities of exogenous metabolites from Chaihu changed with the administration time, but only the signal intensities of large molecule metabolites(m/z 500-850) from Chaihu had a positive correlation with its toxicity. These results suggest that liver toxicity from low doses of Chaihu was probably caused by the larger molecule components and not by its active components, saikosaponin and flavonoid glycoside.
Homochiral metal-organic frameworks(HMOFs) have special properties, such as high surface area, fascinating structures and excellent chemical and thermal stability and they have broad application prospects. In this work, we reported the use of HMOF Co-L-GG(L-GG, dipeptide H-Gly-L-Glu) as the stationary phase for separating racemates in gas chromatography. Co-L-GG coated fused silica capillary column(10 m×250 μm i.d.) was prepared via a dynamic coating method. Thirty racemates belonging to different classes of organic compounds were resolved including halohydrocarbons, ketones, esters, ethers, organic acids, epoxyalkanes, alcohols and sulfoxides. When compared with the previously reported chiral MOFs-coated capillary columns, the Co-L-GG coated column exhibited broader chiral resolution ability towards chiral compounds.
In this paper, a novel compound 3-(2-quinolyl)-5-ferrocenyl-isoxazole(5) with high selectivity toward Cu2+ over other heavy and transition-metal(HTM) ions was designed and synthesized in good yields. The compound not only could be used as an electrochemical probe for Cu2+ with an anodic peak shift of Fe(II)/Fe(III) redox couple, but also could be a colorimetric and fluorescent probe due to the detectable change in color by naked eyes and a significant fluorescence quenching of monomeric anthracene moiety. This highly selective sensing of Cu2+ may be attributed to the unprecedented intermolecular electron-transfer reorganization after the oxidation of the first single electron of compound 5, as indicated by electrospray ionization mass spectrometry(ESI-MS) and density functional theory(DFT) calculation results. To the best of our knowledge, this class of compounds have rarely been reported in the field of molecular sensing. It may have a potential significance for the application of the ferrocenyl-isoxazole derivative in molecular recognition.
Well-channeled porous polyethersulfone(PES) beads were synthesized and used for the immobilization of Comamonas testosteroni QYY cells for an aerobic reactor to remove quinoline, phenol, and other refractory compounds in accidentally-released dye wastewater supplemented with domestic wastewater. The pore size in PES beads mainly depended on the dripping time through the water vapor cylinder. When the cylinder was 2.5 m in length, the pore size in the obtained beads was enlarged to 3 μm, which provided an ideal surface for cells to pass through and grow inside. The reactor with the immobilized C. testosteroni QYY on PES beads resisted organic loading shock and enhanced total organic carbon(TOC) removal, which had 100% removal efficiencies of both quinoline and phenol when the volume ratio of the accidental wastewater to domestic wastewater was increased from 1:2 to 1:1, as compared with the 100% and 34.7% removal efficiencies by the reactor with immobilized C. testosteroni QYY on polyurethane(PU) cube or the 82% and 2.4% removal efficiencies by the reactor with only the suspended C. testosteroni QYY cells, respectively. The PES beads had a specific surface area of 1843 cm2/cm3, which had immobilized (0.024±0.003) g of C. testosteroni QYY cell dry mass/cm3, compared with the specific surface area of 564 cm2/cm3 of the PU cube with (0.018±0.002) g of cell dry mass/cm3. The kinetic study revealed that the quinoline and phenol degradation followed zero-order reactions for all the three reactors. The PES reactor demonstrated the highest quinoline and phenol removal efficiencies. The immobilized C. testosteroni QYY on the low-cost inert PES beads demonstrated good shock resistance and was able to completely remove the toxic compounds, including phenyl carbamate, 2-nitrotoluene, and dioctyl phthalate. Therefore, the beads were ideal for large-scale accidental wastewater treatment.
Five coordination polymers,[Co(H3L)2(dib)]·1.5H2O(1),[Cu(H3L)2(dib)](2),[Co(H2L)(mtpy)]·DMF(3),[Ni(H3L)2(mtpy)(H2O)]·3DMF·H2O(4), and[Cd(H3L)2(pybim)]·1.5H2O(5), have been successfully prepared from 5,11,17,23-tetra-tert-butyl-25-(carboxymethoxy)calixarene, metal salts, and N-donor auxiliary ligands under hy-drothermal conditions[dib=1,4-di(1H-imidazol-1-yl)butane, pybim=2-(2'-pyridyl)benzimidazole, and mtpy=4'-(4-methylphenyl)-2,2':6',2"-terpyridine]. Structural analysis suggests that the metal ion first joins two organic carboxylate ligands to form the independent units, which are further extended by the N-donor auxiliary ligand to give the final structure. Compounds 1 and 2 display 1D infinite chains bridged by a flexible bidentate dib ligand. Compounds 3-5, with multidentate chelate ligands, reveal discrete 0D units. Furthermore, in compounds 3 and 5, 1D supramolecular architectures are exhibited due to π-π interactions.
Systematic structure-activity relationship(SAR) exploration of a moderately active tetrazole-bearing lesinurad-based hit 1f led to the discovery of a potent uric acid transporter 1(URAT1) inhibitor 1i, which possessed a novel molecular skeleton and was 11-fold more potent than the parent lesinurad against human URAT1 in-vitro (IC50=0.66 μmol/L for 1i vs. 7.18 μmol/L for lesinurad).
A series of novel pyridinyl-4,5-2H-isoxazole derivatives was synthesized and their chemical structures were characterized by 1H NMR, 13C NMR as well as MS spectroscopic methods, their melting points were also determined. The inhibitory effects of them against breast cancer cell line(MCF-7) were evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide(MTT) procedure in vitro. Most of them possesed potent anti-proliferative activities, among which compounds 11c and 11j exhibited half maximal inhibitory concentrations(IC50) of 1.9 and 1.5 μmol/L, respectively. These compounds also exhibited potent anti-proliferative activities against both human hepatoma cell line(HepG2) and cervical cancer cell line(HeLa). Preliminary structure-activity relationship (SAR) information from these compounds can be used to guide further exploration of new compounds with better potency as molecular probes. Further study on the mechanism-of-action of these compounds is under investigation.
A new series of 1-substituted phenyl-2-(1H-1,2,4-triazol-1-yl)ethanone derivatives 3a-3f was synthesized and their structures were characterized by IR, 1H NMR, 13C NMR and HRMS spectral analysis. Antimicrobial activities of the derivatives were measured against both bacteria and fungi. In vitro antifungal evaluation showed that five compounds(3b-3f) had growth inhibitory effects on the tested fungus, and three of them(3b, 3c and 3e) showed special efficacy against Gram negative bacteria.
In order to find novel herbicidal active compounds, a series of N-(2,2-dimethyl-7-alkoxy-2,3-dihydro-benzofuran-5-yl)-2-(4-arylxoyphenoxy)propionamides was designed, prepared and evaluated for their herbicidal activity. Bioassay results showed that most of the title compounds had excellent and selective herbicidal activity against the monocotyledonous grasses. In particular, compounds 1g and 1m showed 100% inhibition against the growth of three monocotyledonous grasses under both postemergence and preemergence treatments at the dose of 2250 g/hm2 (1 hm2=104 m2), and could be used as lead compounds for further development of novel potential herbicidal agents.
In order to obtain better anti-cancer compounds, nine glycosylated derivatives were designed and synthesized using diosgenin as starting material. Their structures were confirmed by 1H NMR, 13C NMR and MS spectra. The anti-cancer activities of intermediate compounds 5a-5i and the target compounds 6a-6i were investigated against human leukemia HEL, K562, HL60 and melanoma WM9 cell lines via MTT method. The bioassay results show that these derivatives possess good inhibitory activities against the four cancer cell lines. Furthermore, these derivatives show better inhibitory activities against K562 than against other cell lines, and most derivatives show better inhibitory activities than the parental material. Moreover, compounds 6a-6i are more active than their intermediates 5a-5i when against these cells. The above results demonstrate the effects of glycosylation on 3-OH of diosgenin and acetylation of the sugar moiety on their antitumor activities.
Malate dehydrogenase(MDH) is a key enzyme that catalyzes the reversible oxidation of oxaloacetate to malate and plays an important role in the physiological processes of plant growth and development. However, cyt osolic malate dehydrogenase(cMDH), which is crucial for malate synthesis in the cytosol, still has not been extensively characterized in plants. Here, we isolated a cytosolic malate dehydrogenase gene, designated as GhcMDH1, from Gossypium hirsutum and characterized its possible molecular function in cotton fiber. The cloned cDNA of GhcMDH1 is 1520 base pairs in length, and has an open reading frame of 999 base pairs, encoding for 332 amino acid residues with an estimated molecular weight of 35580 and pI of 6.35. Sequence alignment showed that the deduced amino acid sequence of GhcMDH1 protein shared a high similarity to other plant cMDHs. Confocal and immunological analysis confirmed that GhcMDH1 protein was subcellularly localized to the cytosol. Quantitative real-time polymerase chain reaction(PCR) revealed that GhcMDH1 was constitutively expressed in all vegetative cotton tissues, with slightly lower levels in roots than stems and leaves. Interestingly, the transcripts of GhcMDH1 were detected in 5-25 d post anthesis(DPA) fibers and highly abundant at 15 DPA fibers. The total MDH activities and malate contents of cotton fibers were positively correlated with the fiber elongation rates, suggesting that GhcMDH1 may function in malate synthesis in fast fiber elongation. In agreement with this suspicion, the recombinant His-GhcMDH1 protein mainly drives the reaction towards malate generation in vitro. In conclusion, our molecular characterization of the GhcMDH1 gene provides valuable insights to further investigate the malate equilibrium in cotton fiber development.
In this paper, the polarizable dipole-dipole interaction model was further developed via adding lone-pair dipole moment treatment for nucleobase adenine, cytosine, and guanine. Not only polar covalent bonds, such as C=O, C-O, N-H, C-H and O-H were regarded as bond dipoles, but also nitrogens with lone-pair electrons of adenine, cytosine, and guanine were regarded as lone-pair dipoles. The parameters needed were first determined by treating model complexes. The model was subsequently applied to a series of nucleobase-and nucleoside-containing hydrogen-bonded complexes to rapidly predict the equilibrium hydrogen bond distances and the intermolecular interaction energies. It was observed that the model developed in this work reproduce the MP2/6-31+G(d,p) and B3LYP/6-31+G(d,p) equilibrium hydrogen bond distances with a root mean square error of less than 0.004 nm and the counterpoise-corrected MP2/aug-cc-pVTZ intermolecular interaction energies with a root mean square error of less than 2.93 kJ/mol, which was also highly efficient, demonstrating that the model developed in this work was reasonable and useful.
The corrosion inhibition performances of sodium silicate(Na2SiO3) and acrylamide(AM) for Q235 carbon steel in a high-concentration KCl solution(25%, mass fraction) were investigated via static mass loss method, electrochemical measurements, scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS) and Auger electron spectroscopy(AES). AM shows poor inhibition performance, while Na2SiO3 exhibits a better inhibition performance. Moreover, the steel gains mass instead of losing mass in the presence of 0.5% Na2SiO3 and 0.5% AM, indicating that the corrosion is completely inhibited. SEM analysis indicates that a compact protective film is formed on the steel surface by the combined use of inhibitors. Our results demonstrate that Na2SiO3 and AM could have a synergistic effect on steel corrosion in high concentrations of KCl. The synergistic inhibition mechanism is further conjectured by the XPS and AES analysis.
Cytotoxicities of nickel oxide nanoparticles(NiO NPs) with average diameter of 20 nm were investigated on cultured Chlorella vulgaris. Alga growth-inhibition tests were taken and ultrastructure changes of the microalgae were characterized with transmission electron microscopy(TEM). The biological interface conversion effect between NiO nanoparticles and Chlorella vulgaris was studied by X-ray diffraction(XRD), high-resolution transmission electron microscopy(HRTEM) and X-ray photoelectron spectroscopy(XPS). The results indicated that the NiO nanoparticles had severe inhibitory effect on the growth of microalgae, with a 96 h EC50 value of 31.4 mg/L. Under the exposure to NiO NPs suspensions, Chlorella vulgaris cells showed plasmolysis with a shriveled cell shape, disrupted plasma membrane, leaked cytosol and disordered thylakoid grana lamella. The NiO NPs were aggregated and partially reduced to Ni0 inside the Chlorella vulgaris. The bioaccumulation and bio-reduction ability of Chlorella vulgaris provide us with a possible strategy of remediation of aquatic pollution conducted by toxic metal oxide nanoparticles.
A high-efficiency, low-cost and environment-friendly 2-acrylamide-2-methyl propane sulfonic acid (AMPS)-modified hazelnut-shell-based adsorbent(AHS) was synthesized and used to adsorb Cu2+, Pb2+, methylene blue(MB) and malachite green(MG) from aqueous solutions. The AHS was characterized by means of SEM, BET, FTIR and XPS. Different experimental parameters were evaluated in batch adsorption experiments to determine the optimal adsorption conditions. Adsorption kinetics shows that the adsorption rate is well represented by the pseudo-second-order rate model, and the Langmuir model gives the best fit adsorption isotherm. The Langmuir maximum adsorption capacities were found to be 21.14 mg/g for Cu2+, 32.74 mg/g for Pb2+, 68.03 mg/g for MB and 263.16 mg/g for MG, respectively, while the adsorption capacities could be maintained above 90% even after ten adsorption-desorption cycles. The experimental results show that AHS could be applied to treat both industrial and municipal wastewaters.
Circular dichroism(CD) is usually used to study supramolecular chirality. With the development of CD methods, diffuse transmission CD(DTCD) and diffuse reflectance CD(DRCD) have been developed. However, the relationship among CD, DTCD and DRCD has not been well-studied. A chiral low molecular weight gelator was synthesized, which can result in a transparent physical gel in deionized water. The field-emission electron microscopy images show that the gel is able to self-assemble into left-handed helical fibers. The CD and DTCD spectra are almost identical, but they partially differ from the DRCD spectrum. Based on the TD-DFT calculated CD spectrum, the DRCD spectrum is shown to be more accurate.
Phase equilibria and thermodynamic properties of the CsNO3-KNO3-NaNO3 system and its three subsystems were optimized thermodynamically and validated experimentally. The liquid and end solid solution phases of the KNO3-NaNO3 and CsNO3-KNO3 systems were modeled using the substitutional solution and compound energy formalism models, respectively. The CsNO3-KNO3-NaNO3 ternary system was described thermodynamically based on the self-consistent thermodynamic parameters of the three binary systems. A set of thermodynamic parameters was obtained to reproduce the available information on the thermodynamic properties and phase equilibria. Melting temperature, enthalpy, and specific heat capacity of a eutectic sample were determined using differential scanning calorimetry(DSC). The results show a good consistency with the calculated results, suggesting the reliability of the current thermodynamic database. This work is useful for the construction of multicomponent nitrates and to provide guidance for the development of new medium for thermal energy storage.
A porous ZnO/Ag heterostructure photocatalyst was prepared by a simple one-pot method. The photocatalytic degradation of ammonia and dye indicated that compared with pure ZnO, the photocatalytic activity of ZnO/Ag was significantly improved after Ag modification. The main reason for the improvement of photocatalytic activity is that the recombination process of photoinduced electrons and holes of ZnO was inhibited by interconversion of Ag+ and Ag0 at the surface of ZnO. In addition, the effective separation of the photogenerated carriers can generate more active groups, which can promote the degradation of ammonia and organic dyes.
We reported on a simple and general interfacial self-assembly approach to fabricate plasmonic superlattice sheets in extremely large scale, which can be up to ca. 50 cm2, based on different types of noble metal nanoparticles. The self-assembled nanofilms exhibit exciting plasmonic properties with mirror-like reflectance, represented by vivid colour changes. More important, such superlattice sheets can be easily transferred and explored as highly efficient shape-dependent surface enhanced raman scattering(SERS) substrates, as well as flexible and recyclable shape-dependent substrate-supporting nanocatalysts sheets. The conversion of 4-NPH were kept as high as 95% after the nanocatalyst sheets were used for six cycles. The interfacial self-assembly method can be exploited for development of optical and nanocatalysts devices such as flexible colour filters, molecular sensors and flexible plasmonic nanofilms.
The flame retardancies of three kinds of 9,10-dihydro-9-oxa-10-phosphaphenan-threne 10-oxide(DOPO)-containing flame retardant(A1, A2, A3)/poly(lactic acid)(PLA) composites[PA-n/(Ax-y), n=1-12; x=1, 2, 3, denoting three kinds of flame retardants; y=10%, 20%, 30%, 40%, denoting the mass fraction of Ax] were greatly enhanced by melt blending of flame retardant Ax with PLA, including twin-screw extrusion and injection-molding processes. With only 10%(mass fraction) of Ax added to PLA, good flame retardancy with limiting oxygen index(LOI) values of more than 33% was achieved. As the Ax mass fraction was further increased to 20%, PA-n/(Ax-20%) composites showed much better flame retardancy(LOI≥35% and UL-94 V-0 rating). Moreover, the thermal degradation behaviors and mechanical properties of PA-n/(Ax-y) composites were investigated via thermogravimetric analysis(TGA), differential thermal analysis(DTA), tensile testing, notched impact-bar testing, and dynamic mechanical analysis(DMA). TGA results show that PA-n/(Ax-y) composites have slower rate of mass loss and much higher char yield, compared to neat PLA. With the addition of Ax to PLA, the DTA and DMA results indicate slight variations in glass transition tempe-ratures(Tg) of PA-n/(Ax-y) composites. Based on TGA results under nonisothermal conditions, the thermal degradation kinetics of PA-n/(Ax-y) composites were studied by Kissinger's and Ozawa's methods. These thermal degradation dynamic analyses show lower activation energies(EK or EO) for PA-n/(Ax-y) composites, corresponding to higher mass fractions of Ax(from 10% to 40%). The PA-n/(Ax-y) composites with good flame retardancy and good mecha-nical properties obtained in this study could be potential candidates for fire-and heat-resistant applications in automotive engineering and building fields with more safety and excellent performance.
A new and effective organic-inorganic hybrid hydrophilic anti-fog coating was proposed and prepared. As is well-known, the presence of an inorganic component typically decreases the hydrophilicity and transparency of the coating. To solve this problem, we used polyethylene glycol with two different molecular weights to modify the silane coupling agent and mixed it with hydrophilic copolymer to form coating formulas. We coated these formulas on polycarbonate(PC) substrates to measure the anti-fogging properties via contact angle and anti-fogging tests, compared their transparency properties using UV-Vis spectra and evaluated the hardness using a pencil hardness tester. The results demonstrate that the molecular weight of PEG has a strong influence on the properties of the anti-fog coatings. After the corresponding optimization, we manufactured an excellent anti-fog coating. In addition to good adhesion and hardness, the coating also exhibited excellent mechanical properties, optical transparency and perfect anti-fogging performance.