47 research outputs found
Dichloridobis[3-(4-chlorophenyl)-2,N,N-trimethyl-2,3-dihydro-1,2,4-oxadiazole-5-amine-κN4]platinum(II)–4-chlorobenzaldehyde (1/1)
In the title 1:1 co-crystal, [PtCl2(C11H14ClN3O)2]·C7H5ClO, the coordination polyhedron of the PtII atom is slightly distorted square-planar with the chloride and 2,3-dihydro-1,2,4-oxadiazole ligands mutually trans, as the Pt atom lies on an inversion center. The 4-chlorobenzaldehyde molecules are statistically disordered about an inversion centre with equal occupancies for the two positions. The PtII complex forms a three-dimensional structure through C—H...Cl and weaker C—H...O interactions with the 4-chlorobenzaldehyde molecule
Fullerene Bromides C<sub>70</sub>Br<sub><i>n</i></sub> (<i>n</i> = 8, 10, 14) Synthesis and Identification and Phase Equilibria in the C<sub>70</sub>Br<sub><i>n</i></sub> (<i>n</i> = 8, 10, 14)/Solvent Systems
The paper presents experimental data on synthesis and identification
(IR, UV spectra, TG, DTG, DTA analysis) of the fullerene bromides
C<sub>70</sub>Br<sub><i>n</i></sub> (<i>n</i> =
8, 10, 14). The data on the temperature dependence of solubility in
aromatic solvents (1,2-dichlorobenzene, benzene, 1-methylbenzene,
1,2-dimethylbenzene) in the temperature range (293 to 353 )K are presented
and characterized; compositions of equilibrium solid phases in binary
C<sub>70</sub>Br<sub><i>n</i></sub> (<i>n</i> =
8, 10, 14) + aromatic solvents system are determined
Rhodamine B-Containing Chitosan-Based Films: Preparation, Luminescent, Antibacterial, and Antioxidant Properties
In this study, Rhodamine B-containing chitosan-based films were prepared and characterized using their mechanical, photophysical, and antibacterial properties. The films were synthesized using the casting method and their mechanical properties, such as tensile strength and elongation at break, were found to be dependent on the chemical composition and drying process. Infrared spectroscopy and X-ray diffraction analysis were used to examine the chemical structure and degree of structural perfection of the films. The photophysical properties of the films, including absorption spectra, fluorescence detection, emission quantum yields, and lifetimes of excited states, were studied in detail. Rhodamine B-containing films exhibited higher temperature sensitivity and showed potential as fluorescent temperature sensors in the physiological range. The antibacterial activity of the films was tested against Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli, with Rhodamine B-containing films demonstrating more pronounced antibacterial activity compared to blank films. The findings suggest that the elaborated chitosan-based films, particularly those containing Rhodamine B can be of interest for further research regarding their application in various fields such as clinical practice, the food industry, and agriculture due to their mechanical, photophysical, and antibacterial properties
Biologically Active Supplements Affecting Producer Microorganisms in Food Biotechnology: A Review
Microorganisms, fermentation processes, and the resultant metabolic products are a key driving force in biotechnology and, in particular, in food biotechnology. The quantity and/or quality of final manufactured food products are directly related to the efficiency of the metabolic processes of producer microorganisms. Food BioTech companies are naturally interested in increasing the productivity of their biotechnological production lines. This could be achieved via either indirect or direct influence on the fundamental mechanisms governing biological processes occurring in microbial cells. This review considers an approach to improve the efficiency of producer microorganisms through the use of several types of substances or complexes affecting the metabolic processes of microbial producers that are of interest for food biotechnology, particularly fermented milk products. A classification of these supplements will be given, depending on their chemical nature (poly- and oligosaccharides; poly- and oligopeptides, individual amino acids; miscellaneous substances, including vitamins and other organic compounds, minerals, and multicomponent supplements), and the approved results of their application will be comprehensively surveyed
Biologically Active Supplements Affecting Producer Microorganisms in Food Biotechnology: A Review
Microorganisms, fermentation processes, and the resultant metabolic products are a key driving force in biotechnology and, in particular, in food biotechnology. The quantity and/or quality of final manufactured food products are directly related to the efficiency of the metabolic processes of producer microorganisms. Food BioTech companies are naturally interested in increasing the productivity of their biotechnological production lines. This could be achieved via either indirect or direct influence on the fundamental mechanisms governing biological processes occurring in microbial cells. This review considers an approach to improve the efficiency of producer microorganisms through the use of several types of substances or complexes affecting the metabolic processes of microbial producers that are of interest for food biotechnology, particularly fermented milk products. A classification of these supplements will be given, depending on their chemical nature (poly- and oligosaccharides; poly- and oligopeptides, individual amino acids; miscellaneous substances, including vitamins and other organic compounds, minerals, and multicomponent supplements), and the approved results of their application will be comprehensively surveyed
Triarylazoimidazole-ZnII, CdII, and HgII Complexes: Structures, Photophysics, and Antibacterial Properties
Novel triarylazoimidazoles containing strong electron donors (p-NEt2) or acceptors (p-NO2) by the azoaryl group, and their group 12 metal complexes were synthesized and fully characterized, including X-ray analysis for several complexes. Novel complexes exhibit red photo-luminescence emission (Φ up to  0.21) in a solution. Moreover, the antibacterial activity of complexes was tested against Gram-positive microorganism S. aureus and Gram-negative microorganism E. coli
A Palladium(II) Center Activates Nitrile Ligands toward 1,3-Dipolar Cycloaddition of Nitrones Substantially More than the Corresponding Platinum(II) Center
PalladiumÂ(II)-coordinated NCR<sup>1</sup> (R<sup>1</sup> = Et (<b>1</b>), NMe<sub>2</sub> (<b>2</b>), Ph (<b>3</b>))
species react smoothly with acyclic nitrones such as the ketonitrones
Ph<sub>2</sub>Cî—»NÂ(O)ÂR<sup>4</sup> (R<sup>4</sup> = <i>p-</i>MeC<sub>6</sub>H<sub>4</sub> (<b>4</b>), <i>p-</i>ClC<sub>6</sub>H<sub>4</sub> (<b>5</b>)) and the
aldonitrone <i>p-</i>MeC<sub>6</sub>H<sub>4</sub>CHî—»NÂ(O)ÂMe
(<b>6</b>) in the corresponding nitrile media. This reaction
proceeds as a consecutive two-step intermolecular cycloaddition to
give the mono- and bis-2,3-dihydro-1,2,4-oxadiazole complexes [PdCl<sub>2</sub>(R<sup>1</sup>CN)Â{N<sup><i>a</i></sup>î—»CÂ(R<sup>1</sup>)ÂONÂ(R<sup>4</sup>)<i>C</i><sup><i>b</i></sup>(R<sup>2</sup>R<sup>3</sup>)}]<sup>(<i>a</i>−<i>b</i>)</sup> (<b>7a</b>–<b>13a</b>; R<sup>2</sup>, R<sup>3</sup> = Ph; R<sup>4</sup> = C<sub>6</sub>H<sub>4</sub>Me-<i>p</i>, R<sup>1</sup> = Et (<b>7</b>), NMe<sub>2</sub> (<b>8</b>), Ph (<b>9</b>); R<sup>4</sup> = C<sub>6</sub>H<sub>4</sub>Cl-<i>p</i>, R<sup>1</sup> = Et (<b>10</b>), NMe<sub>2</sub> (<b>11</b>), Ph (<b>12</b>); R<sup>2</sup> = H, R<sup>3</sup> = C<sub>6</sub>H<sub>4</sub>Me-<i>p</i>, R<sup>4</sup> = Me, R<sup>1</sup> = NMe<sub>2</sub> (<b>13</b>)) and [PdCl<sub>2</sub>{N<sup><i>a</i></sup>î—»CÂ(R<sup>1</sup>)ÂONÂ(R<sup>4</sup>)ÂC<sup><i>b</i></sup>(R<sup>2</sup>R<sup>3</sup>)}<sub>2</sub>]<sup>(<i>a</i>−<i>b</i>)</sup> (<b>7b</b>–<b>13b</b>), respectively.
Inspection of the obtained data and their comparison with the previous
results indicate that the Pd<sup>II</sup> centers provide substantially
greater activation of RCN ligands toward the 1,3-dipolar cycloaddition
than the relevant Pt<sup>II</sup> centers. The palladiumÂ(II)-mediated
1,3-dipolar cycloaddition of ketonitrones to nitriles is reversible.
All complexes were characterized by elemental analyses (C, H, N),
high-resolution ESI-MS, and IR and <sup>1</sup>H and <sup>13</sup>CÂ{<sup>1</sup>H} NMR spectroscopy. The structure of <i>trans-</i><b>7b</b> was determined by single-crystal X-ray diffraction.
Metal-free 5-NR′<sub>2</sub>-2,3-dihydro-1,2,4-oxadiazoles
(<b>7c</b>–<b>13c</b>) were liberated from the
corresponding (2,3-dihydro-1,2,4-oxadiazole)<sub>2</sub>Pd<sup>II</sup> complexes by treatment with 1,2-(diphenylphosphino)Âethane, and the
heterocycles were characterized by high-resolution ESI<sup>+</sup>-MS and <sup>1</sup>H and <sup>13</sup>CÂ{<sup>1</sup>H} spectroscopy
Novel Highly Efficient Antibacterial Chitosan-Based Films
In this study, we elaborated new chitosan-based films reinforced by iron(III)-containing chitosan nanoparticles Fe(III)-CS-NPs at different concentrations. We found that the optimum concentration of Fe(III)-CS-NPs for the improvement of antibacterial and mechanical properties of the films was 10% (σb = ca. 8.8 N/mm2, εb = ca. 41%, inhibition zone for S. aureus = ca. 16.8 mm and for E. coli = ca. 11.2 mm). Also, using the click-chemistry approach (thiol–ene reaction), we have synthesized a novel water-soluble cationic derivative of chitin. The addition of this derivative of chitin to the chitosan polymer matrix of the elaborated film significantly improved its mechanical (σb = ca. 11.6 N/mm2, εb = ca. 75%) and antimicrobial (inhibition zone for S. aureus = ca. 19.6 mm and for E. coli = ca. 14.2 mm) properties. The key mechanism of the antibacterial action of the obtained films is the disruption of the membranes of bacterial cells. The elaborated antibacterial films are of interest for potential biomedical and food applications