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•Zn(I3AAH)2)n (1), a 2D polymer of plant hormone (I3AAH2) was synthesized.•The structure of 1 was confirmed by XRD, FT-IR, FT-Raman, 1H and 13C NMR studies.•Zn(II) is bound by four ...oxygen atoms of four O-deprotonated I3AAH− ligands.•For 1, the inhibition zones for bacteria were from 11 mm to 14 mm.
A new 2D coordination polymer of indole‑3‑acetic acid (I3AAH2) with Zn(II), Zn(I3AAH)2n (1) has been synthesized and fully characterized using single-crystal X-ray diffraction, infrared, Raman, 1H and 13C NMR spectroscopy, DFT calculations and microbiological activity tests. The crystal structure is monoclinic, space group P21/n, with a = 6.1948(2), b = 7.4954(3), c = 36.2877(12) Å, β = 94.006(3)°, V = 1680.81(9) Å3 and Z = 4. The Zn atom is bound to four oxygen atoms of four O-deprotonated I3AAH− ligands, in a slightly distorted tetrahedral environment. The carboxylate groups adopt the μ-O,O′ bidentate bridging mode. Non-classical CH⋯O intra- and intermolecular interactions provide ancillary structural stabilization of 1. A theoretical study was carried out at the B3LYP/6–31++G(d,p) level. Detailed vibrational assignment for 1 was based on the calculated PED. The in vitro antibacterial activity against Gram-negative (E. coli, P. aeruginosa) and Gram-positive (B. subtilis, L. monocytogenes and S. aureus) bacteria and in vitro antifungal activity against A. niger and C. albicans of 1 were investigated. For comparison, similar microbiological tests were performed for four other Zn(II) complexes (2–5) with indolecarboxylic acids reported earlier. For 1, the inhibition zones for bacteria were from 11 mm to 14 mm, but for fungi, no inhibition zones were observed. Promising results were obtained for 3, against B. subtilis, L. monocytogenes and A. niger and for 4 against B. subtilis (with inhibition zones >20 mm).
It is estimated that each year more than 2 million people suffer from diarrheal diseases, resulting from the consumption of contaminated meat. Foodborne infections are most frequently caused by small ...Gram-negative rods Campylobacter. The hosts of these bacteria are mainly birds wherein they are part of the normal intestinal flora. During the commercial slaughter, there is a likelihood of contamination of carcasses by the bacteria found in the intestinal content. In Europe, up to 90% of poultry flocks can be a reservoir of the pathogen. According to the European Food Safety Authority report from 2015, the number of reported and confirmed cases of human campylobacteriosis exceeds 200 thousands per year, and such trend remains at constant level for several years. The occurrence of growing antibiotic resistance in bacteria forces the limitation of antibiotic use in the animal production. Therefore, the European Union allows only using stringent preventive and hygienic treatment on farms. Achieving Campylobacter free chickens using these methods is possible, but difficult to implement and expensive. Utilization of bacterial viruses - bacteriophages, can be a path to provide the hygienic conditions of poultry production and food processing. Formulations applied in the food protection should contain strictly lytic bacteriophages, be non-pyrogenic and retain long lasting biological activity. Currently, on the market there are available commercial bacteriophage preparations for agricultural use, but neither includes phages against Campylobacter. However, papers on the application of bacteriophages against Campylobacter in chickens and poultry products were published in the last few years. In accordance with the estimates, 2-logarithm reduction of Campylobacter in poultry carcases will contribute to the 30-fold reduction in the incidence of campylobacteriosis in humans. Research on bacteriophages against Campylobacter have cognitive and economic importance. The paper presents current state of research on bacteriophages targeted against Campylobacter.
•Three tautomers of 5-methylbenzotriazole (5MeBTA) have similar stability.•Vibrational spectra show the presence of 1H- and 3H-5MeBTA tautomers in the solid state.•Formation of NH···N hydrogen bonds ...between the 1H- and 3H-5MeBTA tautomers is confirmed.•5MeBTA is a strong agent against A. niger, C. albicans and L. monocytogenes.
Three tautomeric forms (1H-, 2H-, 3H-) of 5-methylbenzotriazole (5MeBTA) and the tetramer, which includes the 1H-5MeBTA and 3H-5MeBTA tautomers connected by N3−H⋅⋅⋅N3 and N1−H⋅⋅⋅N2 intermolecular hydrogen bonds, have been studied by density functional theory (DFT) using B3LYP, B3LYP-D3 and ωB97XD methods combined with the 6–31++G(d,p) basis set. Calculations for the tetramer have revealed that intermolecular N3⋅⋅⋅N3 distances range from 2.881 to 2.851 Å, while the N1⋅⋅⋅N2 distances vary between 2.965 and 2.915 Å. These distances are very similar to those reported for the crystal of 5MeBTA (R. K. Belter, F. R. Fronczek, CCDC 1971683, 2019). The theoretical Raman and infrared spectra of the tetramer are in a very good agreement with the FT-Raman and FT-IR spectra of 5MeBTA in the solid state, measured in this work. A detailed interpretation of the experimental vibrational spectra has been made on the basis of the calculated potential energy distribution (PED). Microbiological studies in vitro were conducted for 5MeBTA and benzotriazole (BTA) against six bacterial strains (E. coli, K. pneumoniae, P. aeruginosa, B. subtilis, L. monocytogenes and S. aureus) and two fungal strains (A. niger and C. albicans). The results have shown that the substitution by the methyl group at the C-5 atom of BTA leads to an increase in activity against tested strains, in comparison to BTA. For 5MeBTA, the inhibition zones for bacteria and fungi range from 12 mm to 20 mm, and from 13 mm to 24 mm, respectively. The title compound has revealed particularly strong activity against A. niger, C. albicans and L. monocytogenes (with inhibition zones ≥ 20 mm).
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•Structures and vibrational spectra of 5-halo-1H-indole-2-carboxylic acids are studied.•Dimers with dual linear O−H⋅⋅⋅O hydrogen bonds are present in crystal of 5FI2CAH2.•IR and Raman spectra confirm ...the formation of the O−H⋅⋅⋅O dimers in the solid state.•B3LYP and MP2 calculations show that O−H⋅⋅⋅O dimers are the most stable.•5-halo-1H-indole-2-carboxylic acids are strong agents against L. monocytogenes.
Molecular structures and vibrational spectra of 5-fluoro-1H-indole-2-carboxylic acid (5FI2CAH2), 5‑chloro-1H-indole-2-carboxylic acid (5ClI2CAH2) and 5‑bromo-1H-indole-2-carboxylic acid (5BrI2CAH2) have been investigated. Single crystal X-ray diffraction for 5FI2CAH2 has revealed that a pair of 5FI2CAH2 molecules forms a cyclic dimer connected by dual linear O−H⋯O hydrogen bonds, while the NH group of the pyrrole ring does not participate in hydrogen bond. Theoretical studies were performed for the four possible dimers of 5XI2CAH2 (X = F, Cl, Br) using the B3LYP and MP2 methods with the 6–31++G(d,p) basis set. The calculated dimers included various possible combinations of O−H⋯O and N−H⋯O intermolecular interactions. The optimized structural parameters and the calculated vibrational spectra of the studied compounds show a good agreement with the experiment. The in vitro antibacterial activity against Gram-negative (E. coli, K. pneumoniae and P. aeruginosa) and Gram-positive (B. subtilis, L. monocytogenes and S. aureus) bacteria and antifungal activity against A. niger and C. albicans of 5XI2CAH2 have been investigated. All 5XI2CAH2 molecules have revealed particularly high activity against L. monocytogenes which is one of the most common of foodborne pathogens.
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Akademia Młodych Wynalazców to pokazanie młodym ludziom, że nauka może być formą zabawy. Jest to rodzaj zachęty dzieci i młodzieży do kreatywnego myślenia i pobudzenia wyobraźni, a jednocześnie ...pozawala im powiększyć ich wiedzę. Mamy nadzieję, że doda im to wiary we własne umiejętności. Akademia Młodych Wynalazców jest też miejscem nawiązywania nowych znajomości i przyjaźni, bo moc nauki tkwi w sprawnie działającym zespole. Przecież jednym z celów AMW jest integracja dzieci i młodzieży z różnych częstochowskich szkół. Wspólna ich praca nad rozwiązywaniem problemów to najlepsza droga kreowania przyszłych elit. AMW skraca czas i ułatwia nawiązanie kontaktu zdolnych młodych ludzi. Zajęcia na Akademii Młodych Wynalazców są również wyzwaniem dla nauczycieli akademickich, którzy muszą znaleźć odpowiedni sposób przekazywania wiedzy najmłodszym dzieciom, pobudzając ich kreatywne myślenie oraz kształtując ich osobowość.
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