Jūratė Šiugždaitė

Synthesis and Biological Activity of 3-[Phenyl(1,3-thiazol-2-yl)-amino]propanoic Acids and Their Derivatives

New N,N-disubstituted β-amino acids and their derivatives with thiazole, aromatic, and heterocyclic substituents were synthesized from N-phenyl-N-thiocarbamoyl-β-alanine by the Hantzsch method; derivatives with hydrazone fragments were also obtained. Some of the synthesized compounds exhibited discrete antimicrobial activity, and 3-[(4-oxo-4,5-dihydro-1,3-thiazol-2-yl)(phenyl)amino]propanoic acid was found to promote rapeseed growth and to increase seed yield and oil content.

Unexpected transformation of ethyl 1-(4-chlorophenyl)-2-methyl-4-oxo-1,4,5,6-tetrahydropyridine-3-carboxylate and antibacterial activity of the products

The cyclization reaction of N-(4-chlorophenyl)-β-alanine, in the presence of piperidine as a catalyst, provided ethyl 1-(4-chlorophenyl)-2-methyl-4-oxo-1,4,5,6-tetrahydropyridine-3-carboxylate, which reactions with different hydrazines were carried out resulting in formation of a variety of tetrahydropyridine, dihydropyrazolone, and oxazole derivatives in good yields. 5-[2-[(4-Chlorophenyl)amino]ethyl]-4-(1-hydrazinylethylidene)-2,4-dihydro-3H-pyrazol-3-one was converted into a series of hydrazones, which provided tetrahydro-3H-pyrazolo[4,3-c]pyridin-3-one under treatment with acids. The structures of all synthesized compounds were confirmed by IR, 1H NMR, and 13C NMR spectroscopy. The structures of three compounds were unambiguously assigned by means of X-ray analysis data. Some of the synthesized compounds exhibited weak antibacterial activity.Graphical Abstract

Synthesis of novel 1,2- and 2-substituted benzimidazoles with high antibacterial and antioxidant activity

Benzimidazole derivatives are potential candidates for drug development. They are efficiently synthesized and possess various biological properties including antibacterial activity. A series of functionalized benzimidazole derivatives bearing N-(4-chloro- or fluorophenyl)pyrrolidin-2-one or N-(4-chloro- or fluorophenyl)aminobutanoic acid moiety were synthesized. Compounds possessing a very high antibacterial activity, comparable to that of a commercial antibacterial agent oxytetracycline, against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Bacillus cereus were identified. Some of the synthesized compounds exhibited significant antioxidant activity.Graphical abstract

Nucleophilic ring opening of 1,4-disubstituted 2-pyrrolidones with hydrazine. Synthesis of azoles with a high antibacterial activity

3-(1 H -Benzimidazol-2-yl)-4-[(phenyl and 4-substituted phenyl)amino]butanohydrazides were synthesized in good yields by treating the corresponding 4-(1 H -benzimidazol-2-yl)-1-phenyl(substituted phenyl)-2-pyrrolidinones with the excess of hydrazine monohydrate. The utility of the newly synthesized hydrazides in the preparation of pyrroles, pyrazoles, oxadiazoles and triazoles has been demonstrated. All compounds were screened for their antibacterial activity. A significant antibacterial activity was found.

Stable isotope ratio method for the characterisation of the poultry house environment.

ABSTRACT Stable isotope analysis was applied to describe the poultry house environment. The poultry house indoor environment was selected for this study due to the relevant health problems in animals and their caretakers. Air quality parameters including temperature, relative humidity, airflow rate, NH3, CO2 and total suspended particles, as well as mean levels of total airborne bacteria and fungi count, were measured. Carbon isotope ratios (13C/12C) were obtained in size-segregated aerosol particles. The carbon (13C/12C) and nitrogen (15N/14N) isotope ratios were measured in feed, litter, scrapings from the ventilation system, feathers and eggs. Additionally, the distribution of δ13C and δ15N values in different tissues of the chicken was examined. The airborne bacteria and fungi extracted from the air filters collected from poultry farms were grown in the laboratory in media with known isotope values and measured for stable isotope ratios. Analysis of isotope fractionation between microorganisms and their media indicated the applicability of stable isotope analysis in bulk samples for the identification of source material. The analysed examples imply that stable isotope analysis can be used to examine the indoor environment along with its biology and ecology, and serve as an informative bioanalytical tool.