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991.
Di Fiore A Maresca A Alterio V Supuran CT De Simone G 《Chemical communications (Cambridge, England)》2011,47(42):11636-11638
N-substituted benzenesulfonamides, incorporating the N-amino-, N-hydroxy- and N-methoxy-moieties at the sulfonamide zinc binding group, have been investigated as CAIs by means of inhibition and structural studies, unraveling interesting aspects related to their inhibition mechanism. 相似文献
992.
Neal BM Vorushilov AS DeLaRosa AM Robinson RE Berrie CL Barybin MV 《Chemical communications (Cambridge, England)》2011,47(38):10803-10805
Synthesis and self-assembly of structurally related mercapto- and isocyanoazulenes, including novel 2-mercapto-1,3-dicyanoazulene (4) and 2-isocyano-1,3-dicyanoazulene (5), are reported. Exposing 5 adsorbed on Au(111) to a solution of 4 displaces the isocyanoazulene monolayer with that of the mercaptoazulene as judged by ν(C≡N) signatures of these films. 相似文献
993.
994.
995.
Pabis A Szala-Bilnik J Swiatla-Wojcik D 《Physical chemistry chemical physics : PCCP》2011,13(20):9458-9468
Classical molecular dynamics (MD) simulation of ˙OH in liquid water at 37 °C has been performed using flexible models of the solute and solvent molecules. We derived the Morse function describing the bond stretching of the radical and the potential for ˙OH-H(2)O interactions, including short-range interactions of hydrogen atoms. Scans of the potential energy surface of the ˙OH-H(2)O complex have been performed using the DFT method with the B3LYP functional and the 6-311G(d,p) basis set. The DFT-derived partial charges, ±0.375e, and the equilibrium bond-length, 0.975 ?, of ˙OH resulted in the dipole moment of 1.76 D. The radical-water radial distribution functions revealed that ˙OH is not built into the solvent structure but it rather occupies distortions or cavities in the hydrogen-bonded network. The solvent structure at 37 °C has been found to be the same as that of pure water. The hydration cage of the radical comprises 13-14 water molecules. The estimated hydration enthalpy -42 ± 5 kJ mol(-1) is comparable with the experimental value -39 ± 6 kJ mol(-1) for 25 °C. Inspection of hydrogen bonds showed the importance of short-range interaction of hydrogen atoms and indicated that neglect of the angular condition greatly overestimates the number of the H-acceptor radical-water bonds. The mean number ?n = 0.85 of radical-water H-bonds has been calculated using geometric definition of H-bond and ?n = 0.62 has been obtained when the energetic condition, E(da)≤-8 kJ mol(-1), was additionally considered. The continuous lifetimes of 0.033 ps and 0.024 ps have been estimated for the radical H-donor and the H-acceptor bonds, respectively. Within statistical uncertainty the radical self-diffusion coefficient, (2.9 ± 0.6) × 10(-9) m(2) s(-1), is the same as (3.1 ± 0.5) × 10(-9) m(2) s(-1) calculated for water in solution and in pure solvent. To the best of our knowledge, this is the first study of the ˙OH(aq) properties at a biologically relevant body temperature. 相似文献
996.
Anna Rabajczyk 《Central European Journal of Chemistry》2011,9(2):357-366
The Kielce Lake is a water reservoir located in the Kielce city zone. Areas around the reservoir are used for recreational,
residential and industrial purposes. Additionally, the nearby state road to the city of Łódź, is a source of transportation
pollution, including heavy metals. The reservoir is fed by a watercourse which receives municipal wastewater from the town
of Masłów near Kielce. The amount and diversity of organic and inorganic compounds which flow into the reservoir causes heavy
pollution of the Lake waters. To reduce the degree of reservoir pollution, a pulverizing aerator was installed in the middle
of the Kielce Lake in May 2008. Sediment samples were collected at a depth of 0–20 cm between July 2008 and May 2010 at five
sites in the littoral zone of the recultivation area. These environmental samples underwent a five-stage sequential extraction
procedure, assisted by microwave radiation. The concentrations of trace metals Zn, Cu, Ni, Cr, Pb, Mn, Fe and Cd in various
extracts were determined by means of F-AAS and GF-AAS. The results have shown a high concentration of analytes in reservoir
sediments. 相似文献
997.
Helena Dodziuk Anna Bielejewska Wojciech Schilf Haruhisa Ueda 《Central European Journal of Chemistry》2011,9(6):1056-1061
The NMR spectra of [2.2]paracyclophane with β- or γ-cyclodextrin in DMF-d7 at room temperature do not show significant complexation, while HPLC of the complexes in mixed H2O:alcohol solvents demonstrate complexation with different stoichiometries. At 243 K in DMF solution the H3 and H5 NMR signals
of γ-cyclodextrin (but not β) exhibit complexation-induced chemical shifts denoting complex formation. According to HPLC,
at room temperature the [2.2]paracyclophane complex with β-cyclodextrin in 20% H2O:EtOH exhibits 1:2 stoichiometry with K
1 = 1×102 ± 2, K
2 = 9.0×104 ± 2×103 (K = 9×106) while that with γ-cyclodextrin in 50% H2O:MeOH exhibits 1:1 stoichiometry with K
1 = 4×103 ± 150 M−1. Thermodynamic parameters for both complexes have been estimated from the retention time temperature dependence. For the
β-cyclodextrin complexation at 25°C ΔG
0
CD is −39.7 kJ mol−1 while ΔH
0
CD and ΔS
0
CD are −88.2 kJ mol−1 and −0.16 kJ mol−1 K−1. For γ-cyclodextrin, the corresponding values are ΔG
0
CD = −20.5 kJ mol−1, ΔH
0
CD = −33.5 kJ mol−1 and ΔS
0
CD = −0.04 kJ mol−1 K−1.
相似文献
998.
Monzote Fidalgo L Sariego Ramos I García Parra M Cuesta-Rubio O Márquez Hernández I Campo Fernández M Piccinelli AL Rastrelli L 《Natural product communications》2011,6(7):973-976
In this paper we analyzed the antiprotozoal effects of eighteen Cuban propolis extracts (brown, red and yellow type) collected in different geographic areas, using Leishmania amazonensis (as a model of intracellular protozoa) and Trichomonas vaginalis (as a model of extracellular protozoa). All evaluated propolis extracts caused inhibitory effect on intracellular amastigotes of L. amazonensis. However, cytotoxicity on peritoneal macrophages from BALB/c mice was observed. Only five samples decreased the viability of T. vaginalis trophozoites at concentrations lower than 10 microg/mL. No correlation between the type of propolis and antiprotozoal activity was found. Cuban propolis extracts demonstrated activity against both intracellular and extracellular protozoa model, as well as the potentialities of propolis as a natural source to obtain new antiprotozoal agents. 相似文献
999.
A unified quantum <Emphasis Type="Italic">SO</Emphasis>(3) invariant for rational homology 3-spheres
Given a rational homology 3-sphere M with |H
1(M,ℤ)|=b and a link L inside M, colored by odd numbers, we construct a unified invariant I
M,L
belonging to a modification of the Habiro ring where b is inverted. Our unified invariant dominates the whole set of the SO(3) Witten–Reshetikhin–Turaev invariants of the pair (M,L). If b=1 and L=∅, I
M
coincides with Habiro’s invariant of integral homology 3-spheres. For b>1, the unified invariant defined by the third author is determined by I
M
. Important applications are the new Ohtsuki series (perturbative expansions of I
M
) dominating quantum SO(3) invariants at roots of unity whose order is not a power of a prime. These series are not known to be determined by the
LMO invariant. 相似文献
1000.