Synthesis and antimicrobial properties of oligomeric silsesquioxanes containing quaternized nitrogen atoms and hydroxyl groups in organic shell

2017 ◽  
Vol 39 (3) ◽  
pp. 188-194
Author(s):  
M.A. Gumenna ◽  
◽  
N.S. Klimenko ◽  
A.V. Stryutsky ◽  
D.M. Hodyna ◽  
...  
Keyword(s):  
Antimicrobial Properties ◽  
Hydroxyl Groups ◽  
Organic Shell

scholarly journals Structure and Antimicrobial Properties of Monensin A and Its Derivatives: Summary of the Achievements

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Daniel Łowicki ◽  
Adam Huczyński
Keyword(s):  
Antimicrobial Activity ◽  
Lipid Membranes ◽  
Antimicrobial Properties ◽  
Biological Properties ◽  
Sodium Cation ◽  
Hydroxyl Groups ◽  
Carboxyl Group ◽  
Growth Promoter ◽  
Monensin A

In this paper structural and microbiological studies on the ionophorous antibiotic monensin A and its derivatives have been collected. Monensin A is an ionophore which selectively complexes and transports sodium cation across lipid membranes, and therefore it shows a variety of biological properties. This antibiotic is commonly used as coccidiostat and nonhormonal growth promoter. The paper focuses on both the latest and earlier achievements concerning monensin A antimicrobial activity. The activities of monensin derivatives, including modifications of hydroxyl groups and carboxyl group, are also presented.

scholarly journals OLIGOMERIC SILSESQUIOXANES COMBINING AZO- AND FLUORESCENT DYES IN ORGANIC SHELL

2019 ◽  
Vol 85 (4) ◽  
pp. 71-80
Author(s):  
Mariana Gumenna ◽  
Nina Klimenko ◽  
Alexandr Stryutsky ◽  
Alexandr Shevchuk ◽  
Viktor Kravchenko ◽  
...  
Keyword(s):  
Absorption Band ◽  
Rhodamine B ◽  
Fluorescent Dyes ◽  
Hydroxyl Groups ◽  
Uv Spectrum ◽  
Absorption Bands ◽  
Organic Shell ◽  
Similar Band ◽  
Inorganic Nanocomposites ◽  
Epoxy Groups

A method for the synthesis of reactive oligomeric silsesquioxanes, combining fragments of azo dye 4-(phenylazo)phenol and fluorescent dye Rhodamine B in various proportions in an organic shell was developed. These compounds were obtained by the reaction between the oligosilsesquioxane nanoparticles consisting of a mixture of linear, branched, ladder and polyhedral structures with epoxy groups in an organic frame (OSS–Ep) and the dyes. The structure of the synthesized substances was characterized by the methods of IR and 1H NMR spectroscopy. The UV-Vis spectra of OSS–Pp–Rh in DMF solution contain absorption bands characteristic of both acidic (560 and 350 nm) and lactone (in the range of 318–326 nm) forms of Rhodamine B. The absorption band of 4-(phenylazo) phenol fragments corresponding to π−π* transition is observed at 348 nm and overlaps the absorption band of Rhodamine B at 350 nm.The intensity of the absorption bands of fragments of various dyes depends on their content in organic frame of the silsesquioxane core. The intensity of the absorption bands at 348 nm and at 560 nm increases with an increase in the content of 4-(phenylazo)phenol and Rhodamine B correspondingly.It should be noted that when using DMF as a solvent the absorption band corresponding to acidic form of Rhodamine B at 560 nm in the UV-Vis spectra of the compounds obtained is more intense than similar band in the spectrum of the original Rhodamine B. Therefore, the attachment of Rhodamine B to the silsesquioxane core of oligomeric silsesquioxanes mixture does not have a significant effect on the position of absorption maxima in the UV-spectrum and prevents dye’s fragments from converting to the colorless lactone form. In the fluorescence spectra of OSS–Pp–Rh obtained using DMF as a solvent a peak at λ max = 592 nm (λex= 520 nm) is observed. The position of the fluorescence peak and its intensity in the spectra at the same optical density of the medium practically do not depend on the ratio of fragments of 4-(phenylazo)phenol and Rhodamine B in organic frame of OSS–Pp–Rh.  The combination of two different chromophores in organic shell of the silsesquioxane core broadens the range of absorbed light and the change of their ratio allows to adjust the absorption intensity in a certain area. The presence of hydroxyl groups makes it possible to introduce the obtained compounds into the composition of polymeric organic-inorganic nanocomposites by covalent bonding.

Synthesis, antioxidant, DNA cleavage and antimicrobial properties of phthalocyanine complexes bearing the poly-hydroxyl groups

2020 ◽  
Author(s):  
Mehmet Salih Ağırtaş ◽  
Beyza Cabir ◽  
Ümit Yıldıko ◽  
Sadin Özdemir ◽  
Serpil Gonca
Keyword(s):  
Dna Cleavage ◽  
Antimicrobial Properties ◽  
Hydroxyl Groups

scholarly journals Oligomeric silsesquioxanes containing dye Rhodamine B in an organic shell

2019 ◽  
Vol 85 (1) ◽  
pp. 47-57
Author(s):  
Mariana Gumenna ◽  
Nina Klimenko ◽  
Alexandr Stryutsky ◽  
Alexandr Shevchuk ◽  
Viktor Kravchenko
Keyword(s):  
Fluorescence Spectrum ◽  
Rhodamine B ◽  
Bathochromic Shift ◽  
Hydroxyl Groups ◽  
Uv Spectrum ◽  
Absorption Bands ◽  
Lactone Form ◽  
Organic Shell ◽  
Langmuir Blodgett Films ◽  
Fluorescence Peak

A method for the synthesis of amphiphilic reactive oligomeric silsesquioxanes (OSS) with fragments of Rhodamine B fluorescent dye and hydroxyl groups in organic shell (OSS-Rh) by the reaction between carboxyl groups of the dye and epoxy groups of the mixture of oligomeric silsesquioxanes (OSS-Ep) was developed. The structure of the synthesized substance was characterized by the methods of IR and 1H NMR spectroscopy. The UV-spectrum of the OSS-Rh compound in dimethylformamide (DMF) solution was characterized by absorption bands of both the colored zwitterion (562 nm and 350 nm) and the colorless lactone (318 nm) forms of Rhodamine B. The absorption band at 562 nm in the spectrum of OSS-Rh in DMF solution was more intense than the analogous band in the spectrum of the original Rhodamine B. Therefore, the attachment of Rhodamine B to the silsesquioxane core of an oligomeric silsesquioxanes mixture does not have a significant effect on the position of the absorption maxima in UV-spectrum and prevents dye’s fragments from converting to the colorless lactone form. In the fluorescence spectra of both Rhodamine B and OSS-Rh, obtained using ethyl alcohol as a solvent, a peak is observed at λmax = 570 nm (λex = 500 nm). In the fluorescence spectrum of OSS-Rh obtained in DMF, a fluorescence peak is observed at λmax = 586 nm (λex = 520 nm). Consequently, the replacement of ethanol by DMF is accompanied by a bathochromic shift of the fluorescence peak of OSS-Rh. In the fluorescence spectrum of Rhodamine B at the same conditions, the peak of fluorescence is absent because of transition of the dye to the lactone form. The compounds obtained can be used in formation of functional Langmuir-Blodgett films as well as in obtaining polymer nanocomposites by covalent bonding.

scholarly journals Antibacterial Activity of Some Flavonoids and Organic Acids Widely Distributed in Plants

2019 ◽  
Vol 9 (1) ◽  
pp. 109 ◽  
Author(s):  
Artur Adamczak ◽  
Marcin Ożarowski ◽  
Tomasz M. Karpiński
Keyword(s):  
Antibacterial Activity ◽  
Organic Acids ◽  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Dilution Method ◽  
Hydroxyl Groups ◽  
Minimal Inhibitory Concentrations ◽  
Natural Substances ◽  
Flavone Glycosides ◽  
Phenyl Rings

Among natural substances widespread in fruits, vegetables, spices, and medicinal plants, flavonoids and organic acids belong to the promising groups of bioactive compounds with strong antioxidant and anti-inflammatory properties. The aim of the present work was to evaluate the antibacterial activity of 13 common flavonoids (flavones, flavonols, flavanones) and 6 organic acids (aliphatic and aromatic acids). The minimal inhibitory concentrations (MICs) of selected plant substances were determined by the micro-dilution method using clinical strains of four species of pathogenic bacteria. All tested compounds showed antimicrobial properties, but their biological activity was moderate or relatively low. Bacterial growth was most strongly inhibited by salicylic acid (MIC = 250–500 μg/mL). These compounds were generally more active against Gram-negative bacteria: Escherichia coli and Pseudomonas aeruginosa than Gram-positive ones: Enterococcus faecalis and Staphylococcus aureus. An analysis of the antibacterial effect of flavone, chrysin, apigenin, and luteolin showed that the presence of hydroxyl groups in the phenyl rings A and B usually did not influence on the level of their activity. A significant increase in the activity of the hydroxy derivatives of flavone was observed only for S. aureus. Similarly, the presence and position of the sugar group in the flavone glycosides generally had no effect on the MIC values.

scholarly journals Biologically Active Compounds of Plants: Structure-Related Antioxidant, Microbiological and Cytotoxic Activity of Selected Carboxylic Acids

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4454
Author(s):  
Beata Godlewska-Żyłkiewicz ◽  
Renata Świsłocka ◽  
Monika Kalinowska ◽  
Aleksandra Golonko ◽  
Grzegorz Świderski ◽  
...  
Keyword(s):  
Cytotoxic Activity ◽  
Carboxylic Acids ◽  
Antimicrobial Properties ◽  
Transition Metal Ions ◽  
Biologically Active ◽  
Hydroxyl Groups ◽  
Experimental Conditions ◽  
Anti Cancer ◽  
Structural Differences ◽  
Microbial Strain

Natural carboxylic acids are plant-derived compounds that are known to possess biological activity. The aim of this review was to compare the effect of structural differences of the selected carboxylic acids (benzoic acid (BA), cinnamic acid (CinA), p-coumaric acid (p-CA), caffeic acid (CFA), rosmarinic acid (RA), and chicoric acid (ChA)) on the antioxidant, antimicrobial, and cytotoxic activity. The studied compounds were arranged in a logic sequence of increasing number of hydroxyl groups and conjugated bonds in order to investigate the correlations between the structure and bioactivity. A review of the literature revealed that RA exhibited the highest antioxidant activity and this property decreased in the following order: RA > CFA ~ ChA > p-CA > CinA > BA. In the case of antimicrobial properties, structure-activity relationships were not easy to observe as they depended on the microbial strain and the experimental conditions. The highest antimicrobial activity was found for CFA and CinA, while the lowest for RA. Taking into account anti-cancer properties of studied NCA, it seems that the presence of hydroxyl groups had an influence on intermolecular interactions and the cytotoxic potential of the molecules, whereas the carboxyl group participated in the chelation of endogenous transition metal ions.

Antimicrobial properties of tannin extracts as animal feed

2019 ◽  
Author(s):  
S Štumpf ◽  
G Hostnik ◽  
M Leitgeb ◽  
M Primožič ◽  
U Bren
Keyword(s):  
Animal Feed ◽  
Antimicrobial Properties

Bleaching ability of pre-hydrolyzed pulps in the context of a biorefinery mill

TAPPI Journal ◽  
2013 ◽  
Vol 12 (11) ◽  
pp. 49-53 ◽  
Author(s):  
CHRISTINE CHIRAT ◽  
LUCIE BOIRON ◽  
DOMINIQUE LACHENAL
Keyword(s):  
Carbon Content ◽  
Acid Hydrolysis ◽  
13C Nmr ◽  
Kraft Lignin ◽  
Kappa Number ◽  
Hydroxyl Groups ◽  
Kraft Pulps ◽  
Quaternary Carbon ◽  
Oxygen Delignification

Autohydrolysis and acid hydrolysis treatments were applied on mixed softwood chips. The cooking ability was studied by varying the alkali and duration of the cook. Pulps with kappa numbers varying from 30 to 70 were obtained. The bleaching ability of these pulps was studied and compared to control kraft pulps. The prehydrolyzed pulps were shown to be more efficiently delignified by oxygen than the control kraft pulps starting from the same kappa number. Furthermore, the final bleaching was also easier for these pulps. It was also shown that extensive oxygen delignification applied on high-kappa pre-hydrolyzed pulps could be a way to improve the overall yield, which is a prerequisite for the development of such biorefinery concepts. Lignin was isolated from the control kraft and the two pre-hydrolyzed kraft pulps and analyzed by 13C NMR. Lignins from pre-hydrolyzed kraft pulps had similar free phenolic groups content to the control kraft lignin, but their aliphatic hydroxyl groups and β-O-4 content were lower than for the control lignin. The quaternary carbon content was the same for all the samples.

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