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11.
Aleksandra Drzewiecka Krystyna Stepniak Anna Barcicka Anna E. Koziol 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(8):m346-m348
The asymmetric unit in the title compound, {[Cd2(C4H4O6)(SO4)(H2O)5]·3H2O}n, is composed of two cadmium cations, one (R,R)‐tartrate and one sulfate anion, five aqua ligands and three solvent water molecules. One of the cadmium ions is coordinated in an octahedral environment, whereas the second is surrounded by seven O atoms in a pentagonal–bipyramidal geometry. Both types of coordination polyhedra form two sets of perpendicular non‐intersecting polymeric chains. CdO6 octahedra share two corners, while CdO7 units are joined by a bridging carboxylate group. An extensive hydrogen‐bond pattern involving all of the OH groups contributes to the stabilization of the structure. 相似文献
12.
Nesković OM Veljković MV Velicković SR Petkovska LT Perić-Grujić AA 《Rapid communications in mass spectrometry : RCM》2003,17(3):212-214
Ionization energies of hypervalent Li(2)F, Li(2)Cl and Na(2)Cl molecules detected by surface ionization electron impact neutralization mass spectrometry are reported. The ionization energies were 3.78 +/- 0.2 eV for Li(2)F, 4.93 +/- 0.2 eV for Li(2)Cl, and 4.21 +/- 0.2 eV for Na(2)Cl. The ionization energies (IE) agree with theoretical ionization energies calculated by ab initio methods, supporting the theoretical prediction that Li(2)F has a hyperlithiated configuration in which the odd electron delocalizes over the two lithiums and with photoionization measurement. The first ionization energy of Na(2)Cl was experimentally confirmed earlier and for Li(2)Cl as well.8 We have developed and used this new approach for the problem--in the present work ions were first formed by surface ionization, followed by electron attachment (neutralization). 相似文献
13.
Frontera A Saczewski F Gdaniec M Dziemidowicz-Borys E Kurland A Deyà PM Quiñonero D Garau C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(22):6560-6567
Several structures of pi complexes of isocyanuric acid and of several thio derivatives with anions have been computed by using high level ab initio calculations. The nature of the complexes has been studied by means of the method of molecular interaction potential with polarization (MIPp) and Bader's theory of atoms-in-molecules. These molecules form favorable complexes with anions and can be used as binding units for building receptors for the molecular recognition of anions. In several cases, the anion-pi interaction has been demonstrated experimentally by means of X-ray crystallography. 相似文献
14.
Amber L. H. Gray Aleksandra Antevska Benjamin A. Link Bryan Bogin Susan J. Burke Samuel D. Dupuy J. Jason Collier Zachary A. Levine Michael D. Karlstad Thanh D. Do 《Chemical science》2021,12(16):5853
Despite being relatively benign and not an indicative signature of toxicity, fibril formation and fibrillar structures continue to be key factors in assessing the structure–function relationship in protein aggregation diseases. The inability to capture molecular cross-talk among key players at the tissue level before fibril formation greatly accounts for the missing link toward the development of an efficacious therapeutic intervention for Type II diabetes mellitus (T2DM). We show that human α-calcitonin gene-related peptide (α-CGRP) remodeled amylin fibrillization. Furthermore, while CGRP and/or amylin monomers reduce the secretion of both mouse Ins1 and Ins2 proteins, CGRP oligomers have a reverse effect on Ins1. Genetically reduced Ins2, the orthologous version of human insulin, has been shown to enhance insulin sensitivity and extend the life-span in old female mice. Beyond the mechanistic insights, our data suggest that CGRP regulates insulin secretion and lowers the risk of T2DM. Our result rationalizes how migraine might be protective against T2DM. We envision the new paradigm of CGRP : amylin interactions as a pivotal aspect for T2DM diagnostics and therapeutics. Maintaining a low level of amylin while increasing the level of CGRP could become a viable approach toward T2DM prevention and treatment.CGRP concentration is elevated in migraine conditions. The protective effect of migraine against type 2 diabetes is attributed to the ability of CGRP to remodel human amylin aggregation and to suppress the secretion of mouse insulin 2 (the orthologue of human insulin). 相似文献
15.
Iwona Stawoska Jacek Waga Aleksandra Weseucha-Birczyska Micha Dziurka Grayna Podolska Edyta Aleksandrowicz Andrzej Skoczowski 《Molecules (Basel, Switzerland)》2022,27(17)
One of the macronutrients indispensable for plant growth and development is nitrogen (N). It is responsible for starch and storage protein (gliadins and glutenins) biosynthesis and, in consequence, influences kernels’ quality and yields. However, applying N-fertilizers increases gluten content in wheat, and it may intensify the risk of developing allergy symptoms in gluten-sensitive individuals. The purpose of our research was to analyse whether and how the elimination of N-fertilizers during the cultivation of wasko.gl− wheat (modified genotype lacking ω-gliadins) changes the secondary structures of gliadin proteins. To this aim, using the FT-Raman technique, we examined flour and gliadin protein extracts obtained from kernels of two winter wheat lines: wasko.gl+ (with a full set of gliadin proteins) and wasko.gl− (without ω-gliadin fraction) cultivated on two different N-fertilization levels—0 and 120 kg N·ha−1. On the basis of the obtained results, we proved that nitrogen fertilization does not have a major impact on the stability of the secondary structures of gliadin proteins for wasko.gl− wheat line with reduced allergenic properties. Furthermore, the results presented herein suggest the possibility of increasing the stability of glutenin structures as a result of the N-fertilization of wasko.gl− wheat line, which gives hope for its use in the production of wheat articles devoted to people suffering from diseases related to gluten sensitivity. 相似文献
16.
Oleg M. Demchuk Aleksandra Martyna Mateusz Kwanik Katarzyna Szwaczko Dorota Strzelecka Barbara Mirosaw Kazimierz Micha Pietrusiewicz Zofia Urbanczyk-Lipkowska 《Molecules (Basel, Switzerland)》2022,27(17)
The series of C2-symmetric biaryl core-based non-racemic bisphosphines possessing substituents of different electronic properties: both EDG and EWG were obtained in a short sequence of good yielding transformations, started from commercial 1,3-dimethyl-2-nitrobenzene. Several different approaches leading to the desirable ligands were practically evaluated. Notably, the synthesis of the entire series of ligands could be performed with the utilization of a single early-stage precursor DIDAB (6,6′-diiodo-2,2′,4,4′-tetramethylbiphenyl-3,3′-diamine), which could be easily obtained in enantiomerically pure form. The obtained compounds at concentrations of 50 and 200 µM showed various biological activity against normal human dermal fibroblast, ranging from inactivity through time-dependent action and ending up with high toxicity. 相似文献
17.
Joanna Kubik ukasz Waszak Grzegorz Adamczuk Ewelina Humeniuk Magdalena Iwan Kamila Adamczuk Mariola Michalczuk Agnieszka Korga-Plewko Aleksandra Jzefczyk 《Molecules (Basel, Switzerland)》2022,27(21)
The Centaurea L. (Asteraceae) genus includes many plant species with therapeutic properties. Centaurea castriferrei Borbás & Waisb is one of the least known and least described plants of this genus. The aim of the study was the phytochemical analysis of water and methanol–water extracts (7:3 v/v) obtained from the aerial parts of the plant as well as evaluation of their anticancer activity. Quantitative determinations of phenolic compounds and flavonoids were performed, and the antioxidant potential was measured using the CUPRAC method. The RP-HPLC/DAD analysis and HPLC-ESI-QTOF-MS mass spectroscopy were performed, to determine the extracts’ composition. The antiproliferative activity of the obtained extracts was tested in thirteen cancer cell lines and normal skin fibroblasts using MTT test. Regardless of the extraction method and the extractant used, similar cytotoxicity of the extracts on most cancer cell lines was observed. However, the methanol–water extracts (7:3 v/v) contained significantly more phenolic compounds and flavonoids as well as showing stronger antioxidant properties in comparison to water extracts. Centaurea castriferrei Borbás & Waisb is a rich source of apigenin and its derivatives. In all tested extracts, chlorogenic acid and centaurein were also identified. In vitro research revealed that this plant may be a potential source of compounds with anticancer activity. 相似文献
18.
Aleksandra Nurzynska Piotr Piotrowski Katarzyna Klimek Julia Krl Andrzej Kaim Grazyna Ginalska 《Molecules (Basel, Switzerland)》2022,27(14)
This study aimed to develop, characterize, and evaluate antibacterial and cytotoxic properties of novel fullerene derivative composed of C60 fullerenol and standard aminoglycoside antibiotic–gentamicin (C60 fullerenol-gentamicin conjugate). The successful introduction of gentamicin to fullerenol was confirmed by X-ray photoelectron spectroscopy which together with thermogravimetric and spectroscopic analysis revealing the formula of the composition as C60(OH)12(GLYMO)11(Gentamicin)0.8. The dynamic light scattering (DLS) revealed that conjugate possessed ability to form agglomerates in water (size around 115 nm), while Zeta potential measurements demonstrated that such agglomerates possessed neutral character. In vitro biological assays indicated that obtained C60 fullerenol-gentamicin conjugate possessed the same antibacterial activity as standard gentamicin against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli, which proves that combination of fullerenol with gentamicin does not cause the loss of antibacterial activity of antibiotic. Moreover, cytotoxicity assessment demonstrated that obtained fullerenol-gentamicin derivative did not decrease viability of normal human fibroblasts (model eukaryotic cells) compared to control fibroblasts. Thus, taking into account all of the results, it can be stated that this research presents effective method to fabricate C60 fullerenol-gentamicin conjugate and proves that such derivative possesses desired antibacterial properties without unfavorable cytotoxic effects towards eukaryotic cells in vitro. These promising preliminary results indicate that obtained C60 fullerenol-gentamicin conjugate could have biomedical potential. It may be presumed that obtained fullerenol may be used as an effective carrier for antibiotic, and developed fullerenol-gentamicin conjugate may be apply locally (i.e., at the wound site). Moreover, in future we will evaluate possibility of its applications in inter alia tissue engineering, namely as a component of wound dressings and implantable biomaterials. 相似文献
19.
Aleksandra Ilic Jesper Schwarz Catherine Johnson Lisa H. M. de Groot Simon Kaufhold Reiner Lomoth Kenneth Wrnmark 《Chemical science》2022,13(32):9165
Fe–N-heterocyclic carbene (NHC) complexes attract increasing attention as photosensitisers and photoredox catalysts. Such applications generally rely on sufficiently long excited state lifetimes and efficient bimolecular quenching, which leads to there being few examples of successful usage of Fe–NHC complexes to date. Here, we have employed [Fe(iii)(btz)3]3+ (btz = (3,3′-dimethyl-1,1′-bis(p-tolyl)-4,4′-bis(1,2,3-triazol-5-ylidene))) in the addition of alkyl halides to alkenes and alkynes via visible light-mediated atom transfer radical addition (ATRA). Unlike other Fe–NHC complexes, [Fe(iii/ii)(btz)3]3+/2+ benefits from sizable charge transfer excited state lifetimes ≥0.1 ns in both oxidation states, and the Fe(iii) 2LMCT and Fe(ii) 3MLCT states are strong oxidants and reductants, respectively. The combined reactivity of both excited states enables efficient one-electron reduction of the alkyl halide substrate under green light irradiation. The two-photon mechanism proceeds via reductive quenching of the Fe(iii) 2LMCT state by a sacrificial electron donor and subsequent excitation of the Fe(ii) product to its highly reducing 3MLCT state. This route is shown to be more efficient than the alternative, where oxidative quenching of the less reducing Fe(iii) 2LMCT state by the alkyl halide drives the reaction, in the absence of a sacrificial electron donor.An iron complex with N-heterocyclic carbene ligands engages in efficient photoredox catalysis via excited state electron transfer reactions of its Fe(ii) and Fe(iii) oxidation states. 相似文献
20.
Thamara R. dos Santos Jakcline dos Santos Melo Alysson V. dos Santos Patrícia Severino lvaro S. Lima Eliana B. Souto Aleksandra Zieliska Juliana C. Cardoso 《Molecules (Basel, Switzerland)》2022,27(24)
The aim of this study was the development of a cereal bar based on bee pollen (BP), honey (H), and flour by-products (peel passion fruit flour—PPFF), generating an innovative product. BP is a protein-rich ingredient and can be used in the composition of cereal bars. PPFF is a by-product rich in fibers. The formulations were developed using a 23 factorial design with four replicates in the center point, studying the sensory analysis as a response variable. The texture and nutritional parameters were performed for the optimal formulation. BP showed ca. 15% of protein. The final formulation (10.35% BP, 6.8% PPFF, and 25% H) presented 22.2% moisture, 1.8% ash, 0.4% total fat, 3.0% fiber, 63.1% carbohydrates, and 74.0 Kcal/25 g. The sensory analysis presented valued around 7 (typical of a traditional bar). Regarding the possibility of purchasing the product, 51% of the panelists said they would probably buy the developed product. The formulated cereal bar had a similar composition as those already marketed. Moreover, it can be considered a source of fiber and is sensory acceptable. This approach opens up new opportunities for developing nutritional and functional foodstuff with improved sensorial aspects. 相似文献