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51.
Lidija Andro Pavica Planini Marijana Juri 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(9):o337-o340
The asymmetric unit of the title compound, C10H10N22+·2C2HO4−, consists of one half of a 4,4′‐bipyridinium cation, which has inversion symmetry, and a hydrogen oxalate anion, in which an intramolecular hydrogen bond exists. The cations and anions are connected by O—H...O, N—H...O and C—H...O hydrogen bonds, forming a two‐dimensional network, whereas π–π stacking interactions involving the 4,4′‐bipyridinium cations lead to the formation of a three‐dimensional supramolecular structure. An unusual deca‐atomic ring is formed between two hydrogen oxalate anions, which are linked side‐to‐side via O—H...O hydrogen‐bonding interactions. 相似文献
52.
Tetianec L Bratkovskaja I Kulys J Casaite V Meskys R 《Applied biochemistry and biotechnology》2011,163(3):404-414
The kinetic parameters of carbohydrate oxidation catalyzed by Acinetobacter calcoaceticus pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase (GDH) and Escherichia coli PQQ-dependent aldose sugar dehydrogenase (ASDH) were determined using various electron acceptors. The radical cations of
organic compounds and 2,6-dichlorophenolindophenol are the most reactive with both enzymes in presence of glucose. The reactivity
of dioxygen with ASDH is low; the bimolecular constant k
ox = 660 M−1 s−1, while GDH reactivity with dioxygen is even less. The radical cation of 3-(10H-phenoxazin-10-yl)propionic acid was used as electron acceptor for reduced enzyme in the study of dehydrogenases carbohydrates
specificity. Mono- and disaccharide reactivity with GDH is higher than the reactivity of oligosaccharides. For ASDH, the reactivity
increased with the carbohydrate monomer number increase. The specificity of quinoproteins was compared with specificity of
flavoprotein Microdochium nivale carbohydrate oxidase due to potential enzymes application for lactose oxidation. 相似文献
53.
Lidija Gomidželović Dragana Živković Ana Kostov Aleksandra Mitovski Ljubiša Balanović 《Journal of Thermal Analysis and Calorimetry》2011,103(3):1105-1109
The results of comparative thermodynamic analysis of Ga–In–Sb system are presented in this paper. Investigations, carried
out in the section from Ga corner with molar ratio of In:Sb equal to 1:1, were done experimentally, using Oelsen calorimetry
at the temperature 873 K and analytically, applying different calculation methods—Toop and Muggianu, in the temperature interval
from 873 to 1673 K. Excess molar Gibbs energies and activity of all components in specified temperature interval were calculated. 相似文献
54.
Barbara Simončič Brigita Tomšič Lidija Černe Boris Orel Ivan Jerman Janez Kovač Metka Žerjav Andrej Simončič 《Journal of Sol-Gel Science and Technology》2012,61(2):340-354
Cotton fabric was treated with two-component water- and oil-repellent antimicrobial coatings consisting of the commercial
aqueous organic–inorganic hybrid precursors fluoroalkyl-functional siloxane (FAS) and 3-(trimethoxysilyl)-propyldimethyloctadecyl
ammonium chloride (SiQAC) of different concentrations. Two different application procedures were used: a one-step treatment
(S1) by a sol mixture consisting of both precursors [coating FAS-SiQAC (S1)] and a two-step treatment (S2) by SiQAC sol and
then FAS sol [coating SiQAC + FAS (S2)]. The functional properties of the coatings were determined from liquid contact angle
measurements and antimicrobial activity, as well as FTIR and XPS analyses. Although both treatments gave the cotton fabric
superhydrophobic and oleophobic properties at a sufficient sol concentration, procedure S1 was found to be more effective
than procedure S2. The antibacterial properties of the SiQAC + FAS (S2) coating were superior to those of the FAS-SiQAC (S1)
coating. For both two-component coatings, the active bacteriostatic activity of SiQAC was enhanced by the passive antibacterial
activity of FAS. Two-component coatings did not provide significant antifungal protection. Repetitive washing gradually deteriorated
both coatings but the coating applied by procedure S2 seemed to be slightly more durable than that applied by S1. The two-component
coatings caused an increase in the flexibility and a slight decrease in the fabric breaking strength and air permeability
of the cotton sample. 相似文献
55.
Taha Genco Lidija Fras Zemljič Matej Bračič Karin Stana-Kleinschek Thomas Heinze 《Cellulose (London, England)》2012,19(6):2057-2067
Cellulose viscose fibres were functionalized by novel amino cellulose sulfates (ACS), namely 6-deoxy-6-(ω-aminoethyl) amino cellulose-2,3(6)-O-sulfate (AECS), and 6-deoxy-6-(2-(bis-N′,N′-(2-aminoethyl)aminoethyl)) amino cellulose-2,3(6)-O-sulfate (BAECS). In this way an amphoteric characteristics were introduced onto cellulose viscose fibers which is extremely important by fiber applications. Whilst cellulose fibers possess only negligible carboxyl groups’ content, the coating of fibers by AECS and BAECS, respectively, introduces new functional groups to the fibers; as positively-charged amino groups and negatively-charged sulfate groups. The typical functional groups within the non-coated fibers, as well in the ACS-coated fibers, were characterized by means of X-ray photoelectron spectroscopy, conductometric-, potentiometric and polyelectrolyte titrations, as well as conventionally by the spectroscopic methylene-blue method. The electro-kinetic behavior was evaluated by measuring the zeta-potential of the fibers as a function of pH. The amounts of the positive-charges (introduced protonated amino groups) determined by potentiometric titration agreed with the amounts of the positive charges determined by conductometric titration. The total amounts of negatively-charged fiber groups (sulfate and carboxyl) determined by polyelectrolyte titration were 38.8 and 32.1 mMol kg?1 for AECS-Vis and BAECS-Vis, respectively, and these results were in accordance with the conventional methylene-blue method. 相似文献
56.
Veljković J Uzelac L Molčanov K Mlinarić-Majerski K Kralj M Wan P Basarić N 《The Journal of organic chemistry》2012,77(10):4596-4610
Five new (2-adamantyl)naphthol derivatives (5-9, quinone methide precursors, QMP) were synthesized and their photochemical reactivity was investigated by preparative photolyses, fluorescence spectroscopy, and laser flash photolysis (LFP). Excitation of QMP 5 to S(1) leads to efficient excited state intramolecular proton transfer (ESIPT) coupled with dehydration, giving quinone methide QM5 which was characterized by LFP (in CH(3)CN-H(2)O, λ(max) = 370 nm, τ = 0.19 ms). On irradiation of QMP 5 in CH(3)OH-H(2)O (4:1), the quantum yield of methanolysis is Φ = 0.70. Excitation of naphthols QMP 6-8 to S(1) in CH(3)CN leads to photoionization and formation of naphthoxyl radicals. In a protic solvent, QMP 6-8 undergo solvent-assisted PT giving QM6 or zwitterion QM8 that react with nucleophiles delivering adducts, but with a significantly lower quantum efficiency. QMP 9 in a protic solvent undergoes two competitive processes, photosolvolysis via QM9 and solvent-assisted PT to carbon atom of the naphthalene giving zwitterion. QM9 has been characterized by LFP (in CH(3)CN-H(2)O, λ(max) > 600 nm, τ = 0.9 ms). In addition to photogenerated QMs, two stable naphthalene QMs, QM10 and QM11 were synthesized thermally and characterized by X-ray crystallography. QM10 and QM11 do not react with H(2)O but undergo acid-catalyzed fragmentation or rearrangement. Antiproliferative activity of 5-9 was investigated on three human cancer cell lines. Exposure of MCF-7 cells treated with 5 to 300 nm irradiation leads to an enhanced antiproliferative effect, in accordance with the activity being due to the formation of QM5. 相似文献
57.
Rafailović LD Gammer C Rentenberger C Kleber C Whitehead AH Gollas B Karnthaler HP 《Physical chemistry chemical physics : PCCP》2012,14(2):972-980
We demonstrate that nanofabrication of 3D dendritic CoNi alloy foams with an open porous structure can be achieved by electrodeposition onto a single-crystalline Cu(111) substrate at ambient conditions. The very low wettability of this substrate caused by its low surface energy allows tailoring the CoNi deposit morphology. This is concluded from a comparison of polycrystalline Cu substrates with single-crystalline ones of different orientations. The advantages of the present CoNi alloy foams are low internal stresses and good mechanical stability on the substrate. In a second step, by comparing the catalytic properties of the achieved foam with those of CoNi layers obtained on polycrystalline Cu substrates, it is shown that the morphology of the CoNi layers has a decisive influence on the kinetics of the surface redox reaction. The higher reaction rate makes the open foam suitable as catalyst for oxygen evolution in electrolysers. The reversibility of the redox process provides great potential for the achieved porous layers to be used as positive material in alkaline batteries. 相似文献
58.
Mirna Ćurković Perica Ivana Šola Lidija Urbas Franci Smrekar Mladen Krajačić 《Journal of chromatography. A》2009,1216(13):2712-2716
A procedure based on BIA Separations CIM DEAE anion-exchange chromatography was developed to separate double-stranded (ds) RNA of hypovirus infecting phytopathogenic fungus Cryphonectria parasitica. Using a linear gradient of 25 mM 4-morpholinepropanesulfonic acid (MOPS), pH 7.0 as a binding buffer, and 25 mM MOPS, 1.5 M NaCl, 0.1 mM EDTA, 15% isopropanol (v/v), pH 7.0 as an elution buffer, hypoviral dsRNA was additionally purified from nucleic acid species present in preparations partially purified by standard CF-11 cellulose chromatography. Moreover, crude phenol/chloroform extracts of the fungal tissue were also applied to monolithic supports and CIM DEAE chromatograms revealed clear evidence for hypoviral presence without CF-11 chromatography, nucleic acid precipitation, and electrophoresis. 相似文献
59.
Kristina Pavi Maja Beus Goran Poje Lidija Uzelac Marijeta Kralj Zrinka Raji 《Molecules (Basel, Switzerland)》2021,26(21)
As cancer remains one of the major health burdens worldwide, novel agents, due to the development of resistance, are needed. In this work, we designed and synthesized harmirins, which are hybrid compounds comprising harmine and coumarin scaffolds, evaluated their antiproliferative activity, and conducted cell localization and cell cycle analysis experiments. Harmirins were prepared from the corresponding alkynes and azides under mild reaction conditions using Cu(I) catalyzed azide–alkyne cycloaddition, leading to the formation of the 1H-1,2,3-triazole ring. Antiproliferative activity of harmirins was evaluated in vitro against four human cancer cell lines (MCF-7, HCT116, SW620, and HepG2) and one human non-cancer cell line (HEK293T). The most pronounced activities were exerted against MCF-7 and HCT116 cell lines (IC50 in the single-digit micromolar range), while the most selective harmirins were 5b and 12b, substituted at C-3 and O-7 of the β-carboline core and bearing methyl substituent at position 6 of the coumarin ring (SIs > 7.2). Further experiments demonstrated that harmirin 12b is localized exclusively in the cytoplasm. In addition, it induced a strong G1 arrest and reduced the percentage of cells in the S phase, suggesting that it might exert its antiproliferative activity through inhibition of DNA synthesis, rather than DNA damage. In conclusion, harmirin 12b is a novel harmine and coumarin hybrid with significant antiproliferative activity and warrants further evaluation as a potential anticancer agent. 相似文献
60.
Vesna Petrovi Perokovi
eljka Car Josip Draenovi Ranko Stojkovi Lidija Milkovi Mariastefania Antica ani kalamera Sranka Tomi Rosana Ribi 《Molecules (Basel, Switzerland)》2021,26(21)
Muramyl dipeptide (MDP) is the smallest peptidoglycan fragment able to trigger the immune response. Structural modification of MDP can lead to the preparation of analogs with improved immunostimulant properties, including desmuramyl peptides (DMPs). The aim of this work was to prepare the desmuramyl peptide (L-Ala-D-Glu)-containing adamantyl-triazole moiety and its mannosylated derivative in order to study their immunomodulatory activities in vivo. The adjuvant activity of the prepared compounds was evaluated in a murine model using ovalbumin as an antigen, and compared to the reference adjuvant ManAdDMP. The results showed that the introduction of the lipophilic adamantyl-triazole moiety at the C-terminus of L-Ala-D-Glu contributes to the immunostimulant activity of DMP, and that mannosylation of DMP modified with adamantyl-triazole causes the amplification of its immunostimulant activity. 相似文献