Determination of twenty pharmaceutical contaminants in soil using ultrasound-assisted extraction with gas chromatography-mass spectrometric detection.

In this paper, an analytical method for the simultaneous determination of twenty pharmaceuticals (eight non-steroidal anti-inflammatory drugs, five oestrogenic hormones, two antiepileptic drugs, two β-blockers, and three antidepressants) in soils was developed. The optimal method included ultrasound-assisted extraction, a clean-up step on a silica gel column, derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and 1% trimethylchlorosilane (TMCS) in pyridine and ethyl acetate (2:1:1, v/v/v) for 30 min at 60 °C, and determination by gas chromatography-mass spectrometry working in the selected ion monitoring mode. This affords good resolution, high sensitivity and reproducibility, and freedom from interferences even from complex matrices such as soils.

Correction: Ochrobactrum quorumnocens sp. nov., a quorum quenching bacterium from the potato rhizosphere, and comparative genome analysis with related type strains.

[This corrects the article DOI: 10.1371/journal.pone.

Ochrobactrum quorumnocens sp. nov., a quorum quenching bacterium from the potato rhizosphere, and comparative genome analysis with related type strains.

Ochrobactrum spp. are ubiquitous bacteria attracting growing attention as important members of microbiomes of plants and nematodes and as a source of enzymes for biotechnology. Strain Ochrobactrum sp.

The uniform structure of O-polysaccharides isolated from Dickeya solani strains of different origin.

O-polysaccharides were isolated from lipopolysaccharides obtained from four different strains of plant pathogenic bacteria belonging to the species Dickeya solani: two of them were isolated in Poland (IFB0099 and IFB0158), the third in Germany (IFB0223) and the last one, D. solani Type Strain IPO2222, originated from the Netherlands. In addition, the O-polysaccharide of a closely related species D.

Structural characterization of the O-polysaccharide isolated from Franconibacter helveticus LMG23732(T).

The bacterial strain Franconibacter helveticus LMG 23732(T) was previously misidentified as the neonatal pathogen Cronobacter zurichensis. O-polysaccharide (OPS) is a part of lipopolysaccharide (LPS), which is an important cell envelope compound of Gram-negative bacteria. OPS isolated from the bacterium Franconibacter helveticus LMG23732(T) was characterized by chemical analyses as well as 1D and 2D NMR experiments.

The structure of O-polysaccharides isolated from plant pathogenic bacteria Pectobacterium wasabiae IFB5408 and IFB5427.

O-Polysaccharides were isolated from the lipopolysaccharides of two strains of plant pathogenic bacteria Pectobacterium wasabiae isolated in Poland in 2013 (IFB5408 and IFB5427). The purified polysaccharides were analyzed using 1D and 2D NMR spectroscopy ((1)H, DQF-COSY, TOCSY, ROESY, HSQC, HSQC-TOCSY, and HMBC) and the chemical methods. Sugar and methylation analyses of native polysaccharides, absolute configuration assignment of constituent monosaccharides together with NMR spectroscopy data revealed that the chemical structures of both O-polysaccharides are the same.

Structural studies of O-polysaccharide isolated from Cronobacter sakazakii Sequence Type 12 from a case of neonatal necrotizing enterocolitis.

The O-polysaccharide (OPS) of Cronobacter sakazakii NTU 696 (Sequence Type 12) from a case of neonatal necrotizing enterocolitis was isolated from the polysaccharide fraction obtained after lipopolysaccharide (LPS) hydrolysis. Purified OPS was analyzed by NMR spectroscopy ((1)H, COSY, TOCSY, NOESY, HSQC, HSQC-TOCSY and HMBC experiments) and chemical methods. Obtained monosaccharide derivatives analyzed by gas chromatography and gas chromatography-mass spectrometry allowed the identification of six sugar components.

The structure of O-polysaccharide isolated from Cronobacter universalis NCTC 9529T.

The O-polysaccharide (OPS) was isolated from Cronobacter universalis NCTC 9529(T), a new species in the genus Cronobacter, which was created by the reclassification of the species Enterobacter sakazakii. Purified polysaccharide was analyzed by NMR spectroscopy ((1)H, COSY, TOCSY, ROESY, HSQC, and HSQC-TOCSY) and chemical methods. The monosaccharide derivatives were analyzed by gas chromatography and gas chromatography-mass spectrometry.

Detection of denatonium benzoate (bitrex) remnants in noncommercial alcoholic beverages by Raman spectroscopy.

Illegal alcoholic beverages are often introduced into market using cheap technical alcohol, which is contaminated by denatonium benzoate (Bitrex) of very small concentration. Bitrex is the most bitter chemical compound and has to be removed before alcohol consumption. The home-made methods utilize sodium hypochlorite to disintegrate particles of denatonium benzoate in alcohol and to remove bitter taste before trading.

A new silylation reagent dimethyl(3,3,3-trifluoropropyl)silyldiethylamine for the analysis of estrogenic compounds by gas chromatography-mass spectrometry.

In this study we applied DIMETRIS (dimethyl(3,3,3-trifluoropropyl)silyldiethylamine), a new silylating reagent, to derivative natural estrogens such as estrone (E1), 17β-estradiol (E2) and estriol (E3), as well as the synthetic 17α-ethinylestradiol (EE2) and the non-steroid diethylstilbestrol (DES). Its derivatizing properties were compared with those of the commonly used mixture of BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide)+1% trimethylchlorosilane (TMCS) and with MTBSTFA (N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide). The use of DIMETRIS for the silylation all of them is reported for the first time.

Chemometric optimization of derivatization reactions prior to gas chromatography-mass spectrometry analysis.

Derivatization is a methodological technique that can be used to make an organic compound more suitable for qualitative and/or quantitative analysis (e.g. pharmaceuticals).

Chemical structure of the O-polysaccharides isolated from Cronobacter turicensis sequence type 5 strains 57, 564, and 566.

The Cronobacter spp. are Gram-negative bacterial pathogens that can cause infections in all age groups, and have a high mortality rate in neonates due to necrotizing enterocolitis and meningitis. Recent genotyping studies have revealed a strong clonal lineage in the genus, but this has not been compared with physiological traits.

Immunochemical studies of Salmonella Dakar and Salmonella Telaviv O-antigens (serogroup O:28).

Salmonella Dakar and Salmonella Telaviv bacteria belong to serogroup O:28, which represents 107 serovars and possesses only the epitope O28. Salmonella Telaviv has the subfactors O28(1) and O28(2) , whereas S. Dakar has O28(1) and O28(3) .

Chemical structure of the O-polysaccharide isolated from Pectobacterium atrosepticum SCRI 1039.

The lipopolysaccharide (LPS) of the bacterium Pectobacterium atrosepticum SCRI 1039 was hydrolyzed and the products were separated. A study of the obtained O-polysaccharide by means of chemical methods, GLC, GLC-MS, and NMR spectroscopy allowed us to identify a branched polymer with a pentasaccharide repeating unit of the structure shown below, in which the fucose residue was partially O-acetylated at C-2, C-3 or C-4.

Chemical structure of wall teichoic acid isolated from Enterococcus faecium strain U0317.

Wall teichoic acid (WTA) was isolated from Enterococcus faecium strain U0317 and structurally characterized using (1)H, (13)C, and (31)P NMR spectroscopy, including two-dimensional COSY, TOCSY, ROESY, HMQC, and HMBC experiments. Further compositional determination was undertaken using classical chemical methods and HF treatment followed by GLC and GLC-MS analyses. The repeating unit of WTA consisted of two residues of 2-acetamido-2-deoxy-D-galactose, glycerol (Gro), and phosphate, and has the structure shown below: [See formula in text].

Heterogeneous structure of O-Antigenic part of lipopolysaccharide of Salmonella Telaviv (Serogroup O:28) containing 3-Acetamido-3,6-dideoxy-D-glucopyranose.

The O-polysaccharide of Salmonella Telaviv was obtained by mild acid degradation of the lipopolysaccharide and studied by chemical methods (sugar and methylation analyses, Smith degradation, de-O-acetylation) and NMR spectroscopy. The structure of the O-polysaccharide was established. The repeating units that are proximal to the lipopolysaccharide core region mostly have a digalactose side chain and lack glucose, whereas those at the other end of the chain mostly do bear glucose but are devoid of the disaccharide side chain.

Unexpected photoproduct generated via the acetone-sensitized photolysis of 5-bromo-2'-deoxyuridine in a water/isopropanol solution: experimental and computational studies.

The acetone-sensitized photolysis of 5-bromo-2'-deoxyuridine (5-BrdU) in a water/isopropanol solution with 300 nm photons leads to the formation of 2'-deoxyuridine (dU) and a comparable amount of another photoproduct that has not been reported in the literature so far. The negative and positive mass spectra recorded for this species indicate that they originate from the molecular mass of 286 Da, which corresponds to an adduct of 2'-deoxyuridine and 2-propanol. Quantum chemical calculations carried out at the DFT and TDDFT levels reveal both the structure and the UV spectrum of that adduct.

Application of spectroscopic methods for structural analysis of chitin and chitosan.

Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry. Two of the main reasons for this are firstly the unique chemical, physicochemical and biological properties of chitin and chitosan, and secondly the unlimited supply of raw materials for their production. These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production.

Structure of the O-polysaccharide isolated from Cronobacter sakazakii 767.

The Cronobacter spp., previously known as Enterobacter sakazakii, are Gram-negative enterobacterial pathogens that can cause necrotizing enterocolitis, meningitis, and septicemia with a high mortality rate in neonates. The O-specific polysaccharide (O-PS) was isolated from Cronobacter sakazakii strain 767 and structurally characterized using (1)H and (13)C NMR spectroscopy, including two-dimensional DQF-COSY, TOCSY, ROESY, HSQC, and HMBC experiments.

Identification of ionic liquid breakdown products in an advanced oxidation system.

Commonly used alkylimidazolium ionic liquids are poorly to negligibly biodegradable, and some are toxic, with the potential to poison typical biological test systems. Therefore, when ionic liquids are present in technological wastewaters they could break through classical wastewater treatment systems into natural waters and become potentially persistent pollutants. A recent study investigating different advanced oxidation processes found that the H(2)O(2)/UV system degraded dissolved imidazolium ionic liquids with the greatest efficiency.

Smith degradation of the O-antigenic polysaccharide of Salmonella Dakar: structural studies of the products.

Two different oligosaccharides were obtained from the Smith degradation of the O-polysaccharide isolated from the lipopolysaccharide of Salmonella Dakar. The structures of these oligosaccharides were investigated by chemical analysis, NMR spectroscopy and MALDI-TOF mass spectrometry. The following structures of these products were determined: alpha-D-GalpNAc-(1-->4)-alpha-D-Quip3NAc-(1-->3)-alpha-L-Rhap-(1-->2)-threitol and [Formula: see text] where Quip3NAc is 3-acetamido-3,6-dideoxyglucose.

Effective biotic elicitation of Ruta graveolens L. shoot cultures by lysates from Pectobacterium atrosepticum and Bacillus sp.

Growth of Ruta graveolens shoots was induced when Bacillus sp. cell lysates were added to the culture medium. Elicitation of coumarin by this lysate was also very effective; the concentrations of isopimpinelin, xanthotoxin and bergapten increased to 610, 2120 and 1460 microg g(-1) dry wt, respectively.

Assessing toxicity and biodegradation of novel, environmentally benign ionic liquids (1-alkoxymethyl-3-hydroxypyridinium chloride, saccharinate and acesulfamates) on cellular and molecular level.

Ionic liquids are widely studied as alternative solvents in organic synthesis and catalysis, in electrochemistry and the separation sciences; with their many applications they will soon be produced on an industrial scale. Available toxicological data of ionic liquids have already suggested initial guidelines for the conscious design of safer chemicals. In this study a new group of such redesigned ionic liquids-1-alkoxymethyl-3-hydroxypyridinium cations+acesulphamate, saccharinate and chloride anions-was assayed with respect to their inhibitory activity towards acetylcholinesterase and their cellular toxicity towards the IPC-81 rat promyelocytic leukaemia cell line: the acute biological activity of these compounds is very low.

The structure of the O-polysaccharide isolated from the lipopolysaccharide of Salmonella Dakar (serogroup O:28).

The structure of the O-antigenic part of the lipopolysaccharide (LPS) of Salmonella Dakar was analysed using chemical methods, NMR spectroscopy and mass spectrometry. The following structure for the repeating unit of the O-polysaccharide was determined: [see text] where Quip3NAc is 3-acetamido-3,6-dideoxyglucose. This is the first published structure of the O-polysaccharides from 101 serotypes of Salmonella bacteria belonging to serogroup O:28 (formerly M) in the Kauffmann-White scheme.

Structure and heterogeneity of the O-antigen chain of Salmonella Agona lipopolysaccharide.

Lipopolysaccharide of Salmonella Agona smooth-type cells was obtained from bacteria by a hot phenol-water extraction procedure. Mild acid hydrolysis of lipopolysaccharide, followed by gel filtration, yielded the pure O-polysaccharide. Abequose, rhamnose, mannose, galactose and glucose in the molar ratio 0.