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61.
Hanna Kowalska Agata Marzec Ewa Domian Ewelina Masiarz Agnieszka Ciurzyska Sabina Galus Aleksandra Makiewicz Andrzej Lenart Jolanta Kowalska 《Molecules (Basel, Switzerland)》2020,25(23)
Japanese quince has high health value, but due to its taste and texture, it is difficult to eat raw. The use of innovative drying methods to produce dried snack foods from these fruits may be of interest to producers and consumers. The physicochemical and sensory properties of 3 mm slices of Japanese quince fruit (with skin, without seeds) obtained by osmotic pre-treatment in chokeberry and apple juice concentrates, and with the use of convection (convective drying, C-D), freeze-drying (F-D), and convection-microwave-vacuum drying (hybrid) are assessed. The methods of drying osmo-dehydrated slices do not affect the dry matter content. In most dried quince, the water activity is 0.40 or lower. Pre-osmotic dehydration and drying have a significant impact on the mechanical and acoustic properties of quince chips. Sensory attractive chips emit loud acoustic emission (AE) during the breaking test. Chips that are osmo-dehydrated in a mixture of chokeberry juice concentrate and sucrose and dried by a hybrid method are attractive. They have a dark red color given by chokeberry concentrate and a slight sweet (with a slight sour-bitter) taste. The sensory evaluation was useful for determining the quality of the chips in terms of their texture (crispness) tested by mechanical methods. Their sensory ratings (overall desirability as weight of color, taste, crispness, and flavor) are high and similar (from 3.8 to 4.1). The use of innovative drying methods with pre-osmotic treatment allows obtaining dried material with properties comparable to those obtained by the F-D method, but in a much shorter time, i.e., with lower energy and using a simple method. 相似文献
62.
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
63.
JPC – Journal of Planar Chromatography – Modern TLC - The lipophilicity of 2,6-disubstituted 7-methylpurines and 6-mer-captopurine has been determined by reversed-phase thin-layer... 相似文献
64.
Renata Kasprzyk Beata J. Starek Sylwia Ciechanowicz Dorota Kubacka Joanna Kowalska Jacek Jemielity 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(27):6728-6740
The m7G cap is a unique nucleotide structure at the 5′-end of all eukaryotic mRNAs. The cap specifically interacts with numerous cellular proteins and participates in biological processes that are essential for cell growth and function. To provide small molecular probes to study important cap-recognizing proteins, we synthesized m7G nucleotides labeled with fluorescent tags via the terminal phosph(on)ate group and studied how their emission properties changed upon protein binding or enzymatic cleavage. Only the pyrene-labeled compounds behaved as sensitive turn-on probes. A pyrene-labeled m7GTP analogue showed up to eightfold enhanced fluorescence emission upon binding to eukaryotic translation initiation factor 4E (eIF4E) and over 30-fold enhancement upon cleavage by decapping scavenger (DcpS) enzyme. These observations served as the basis for developing binding- and hydrolytic-activity assays. The assay utility was validated with previously characterized libraries of eIF4E ligands and DcpS inhibitors. The DcpS assay was also applied to study hydrolytic activity and inhibition of endogenous enzyme in cytoplasmic extracts from HeLa and HEK cells. 相似文献
65.
Magdalena Kowalska ukasz Fijakowski Monika Kubacka Kinga Saat Grzegorz Grzek Jacek Nowaczyk Alicja Nowaczyk 《Molecules (Basel, Switzerland)》2021,26(12)
Tiagabine is an antiepileptic drug used for the treatment of partial seizures in humans. Recently, this drug has been found useful in several non-epileptic conditions, including anxiety, chronic pain and sleep disorders. Since tachycardia—an impairment of cardiac rhythm due to cardiac ion channel dysfunction—is one of the most commonly reported non-neurological adverse effects of this drug, in the present paper we have undertaken pharmacological and numerical studies to assess a potential cardiovascular risk associated with the use of tiagabine. A chemical interaction of tiagabine with a model of human voltage-gated ion channels (VGICs) is described using the molecular docking method. The obtained in silico results imply that the adverse effects reported so far in the clinical cardiological of tiagabine could not be directly attributed to its interactions with VGICs. This is also confirmed by the results from the isolated organ studies (i.e., calcium entry blocking properties test) and in vivo (electrocardiogram study) assays of the present research. It was found that tachycardia and other tiagabine-induced cardiac complications are not due to a direct effect of this drug on ventricular depolarization and repolarization. 相似文献
66.
67.
A new method for the analysis of three ecological insecticides, namely azadyrachtin, spinosad (sum of spinosyn A and spinosyn
D) and rotenone, in produce and soil samples is presented. Investigated compounds are one of the most significant insecticides
authorized for organic farming crop protection in many countries. Extraction of the pesticides from plant and soil matrices
was performed by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. The method entailed a
single extraction of the investigated compounds with acidified acetonitrile followed by a dispersive solid-phase extraction
cleanup step prior to the final determination by reverse-phase ultra-performance liquid chromatography/tandem quadrupole mass
spectrometry (UPLC-MS/MS). Validation studies were carried out on cabbage, tomato and soil samples. Recoveries of the spiked
samples were in the range between 67% and 108%, depending on the matrix and the spiking level. Relative standard deviations
for all matrix–compound combinations did not exceed 12%. The limits of quantification were ≤0.01 mg kg−1 in all cases, except for azadirachtin. The developed method was applied to the analysis of real samples originating from
organic farming production. 相似文献
68.
Heinrich Puff Heide Hevendehl Kornelia Höfer Hans Reuter Willi Schuh 《Journal of organometallic chemistry》1985,287(2):163-178
The di-t-butyltin hydroxide halides t-Bu2Sn(OH)X (X = F, Cl or Br) have been prepared starting from the dihalides t-Bu2SnX2 or the oxide (t-Bu2SnO)3. X-Ray analysis of the three compounds shows dimeric molecules: two 5-coordinated tin atoms and the oxygen atoms of the hydroxyl groups are linked to a four-membered ring. As confirmed by the IR spectra, the molecules in the crystal are held together by OH?X hydrogen bonds. These are strong in the hydroxide fluoride but are weak in the analogous chloride and bromide. 相似文献
69.
T. Kowalska 《Chromatographia》1990,30(5-6):298-300
Summary We apply our new retention model introduced elsewhere to the studies of intermolecular interactions between the solute and
the remaining components of a normal-phase HPLC system using a binary mobile phase consisting of an alcohol and a hydrocarbon.
This can be achieved through the analysis of the regressional parameters A, B, and C appearing in the relationship of solute
retardation (RF) vs. mobile phase composition. Negative values of these parameters indicate a greater affinity of the solute to the stationary
phase than to a given mobile phase moiety, whereas positive values have a reverse meaning. According to the absolute values
of A, B, and C solute groups can be arranged according to the affinity toward a given mobile phase moiety, which is a detailed
and important information regarding their separation, the stationary phase and with each individual constituent of the mobile
phase. 相似文献
70.
The Karl Fischer titration is based on a specific chemical reaction. Several measures exist to make all the water of insoluble
samples accessible for the chemical reactants. The most efficient are the titration at elevated temperatures, the use of a
homogenizer in the titration vessel and the modification of the polarity of the working medium (essentially methanol) by the
addition of appropriate solvents like chloroform or formamide. It is known however that formamide interferes with the Karl
Fischer reaction and so causes more or less false results. This effect increases with higher temperatures. A method is therefore
presented to avoid this interference, even when working at the boiling point of the working medium. It takes advantage of
the fact that the side reaction has a practically constant velocity, at least as long as usual titrations last. Thus, a constant
additional consumption of Karl Fischer reagent is observed. This can be accounted for by measuring this effect before the
start of the determination and by deducting the additional reagent consumption, which is proportional to the duration of the
titration, from the totally added volume. With certain modern titrators this can even be carried out automatically. They can
continuously measure the so-called drift, the titration rate necessary to keep the titration cell dry, and have the capability
to use this drift as stop criterion for the titration. This means that the analysis is terminated when the drift existing
before the titration is reached again. The additional consumption of reagent, to be deducted from the total volume, can (automatically)
be calculated from the drift rate and the titration time. The proposed procedure allows the use of formamide as additional
solvent, even at high temperatures, in order to shorten determination times considerably. It avoids false results due to the
interference, which has so far prevented its use when exact results were desired and when the duration of the analysis was
long.
Received: 30 May 1996 / Revised: 26 July 1996/Accepted: 30 July 1996 相似文献