Antibiotic residues in the cirata reservoir, Indonesia and their effect on ecology and the selection for antibiotic-resistant bacteria.

Antibiotic residues, their mixture toxicity, and the potential selection for antibiotic-resistant bacteria could pose a problem for water use and the ecosystem of reservoirs. This study aims to provide a comprehensive understanding of the occurrence, concentration, distribution, and ecological risks associated with various antibiotics in the Cirata reservoir, Indonesia. In our water and sediment samples, we detected 24 out of the 65 antibiotic residues analyzed, revealing a diverse range of antibiotic classes present.

Brominated Dioxins in Egg, Broiler, and Feed Additives: Significance of Bioassay-Directed Screening for Identification of Emerging Risks in Food.

Food authorities aim to safeguard our food. This requires sensitive analyses to guarantee detection of both banned and regulated substances at low concentrations. At the same time, broad screening methods are needed to identify new emerging risks.

Comparison of Compound Identification Tools Using Data Dependent and Data Independent High-Resolution Mass Spectrometry Spectra.

Liquid chromatography combined with high-resolution mass spectrometry (LC-HRMS) is a frequently applied technique for suspect screening (SS) and non-target screening (NTS) in metabolomics and environmental toxicology. However, correctly identifying compounds based on SS or NTS approaches remains challenging, especially when using data-independent acquisition (DIA). This study assessed the performance of four HRMS-spectra identification tools to annotate in-house generated data-dependent acquisition (DDA) and DIA HRMS spectra of 32 pesticides, veterinary drugs, and their metabolites.

Bioassay-directed analysis-based identification of relevant pyrrolizidine alkaloids.

Pyrrolizidine alkaloids (PAs) are produced by various plant species and have been detected as contaminants in food and feed. Monitoring programmes should include PAs that are present in relevant matrices and that exhibit a high toxic potential. The aim of the present study was to use a bioassay-directed analysis approach to identify relevant PAs not yet included in monitoring programmes.

Systematic assessment of acquisition and data-processing parameters in the suspect screening of veterinary drugs in archive matrices using LC-HRMS.

Monitoring strategies for veterinary drugs in products of animal origin are shifting towards a more risk-based approach. Such strategies not only target a limited number of predefined .substances but also facilitate detection of unexpected substances.

A single method to analyse residues from five different classes of prohibited pharmacologically active substances in milk.

In the European Union, the use of veterinary drugs belonging to the A6 group is prohibited in food-producing animals according to Commission Regulation (EU) No. 2010/37. The aim of this study was to improve the analytical control strategy by developing a single method to analyse residues of prohibited pharmacologically active substances in milk.

Global monitoring of antimicrobial resistance based on metagenomics analyses of urban sewage.

Antimicrobial resistance (AMR) is a serious threat to global public health, but obtaining representative data on AMR for healthy human populations is difficult. Here, we use metagenomic analysis of untreated sewage to characterize the bacterial resistome from 79 sites in 60 countries. We find systematic differences in abundance and diversity of AMR genes between Europe/North-America/Oceania and Africa/Asia/South-America.

A new extraction procedure to abate the burden of non-extractable antibiotic residues in manure.

Through agricultural soil fertilization using organic manure, antibiotic residues can accumulate in the environment. In order to assess the risks of environmental pollution by veterinary drugs, monitoring of manure for antibiotic residues is necessary. As manure is a complex matrix, extraction of antibiotics proved to be challenging.

QSAR-based molecular signatures of prenylated (iso)flavonoids underlying antimicrobial potency against and membrane-disruption in Gram positive and Gram negative bacteria.

Prenylated flavonoids and isoflavonoids are phytochemicals with remarkable antibacterial activity. In this study, 30 prenylated (iso)flavonoids were tested against Listeria monocytogenes and Escherichia coli (the latter in combination with an efflux pump inhibitor). Minimum inhibitory concentrations of the most active compounds ranged between 6.

Multiple heart-cutting two dimensional liquid chromatography quadrupole time-of-flight mass spectrometry of pyrrolizidine alkaloids.

Pyrrolizidine alkaloids (PAs) and their and the corresponding N-oxides (PAs-ox) are genotoxic plant metabolites which can be present as unwanted contaminants in food products of herbal origin like tea and food supplements. PAs and PAs-ox come in a wide variety of molecular structures including many structural isomers. For toxicity assessment it is important to determine the composition of a sample and to resolve all isomeric PAs and PAs-ox, which is currently not possible in one liquid or gas chromatographic (LC or GC) run.

Glyceollins and dehydroglyceollins isolated from soybean act as SERMs and ER subtype-selective phytoestrogens.

Seven prenylated 6a-hydroxy-pterocapans and five prenylated 6a,11a-pterocarpenes with different kinds of prenylation were purified from an ethanolic extract of fungus-treated soybean sprouts. The activity of these compounds toward both human estrogen receptors (hERα and hERβ) was determined in a yeast bioassay and the activity toward hERα was additionally tested in an U2-OS based hERα CALUX bioassay. In the yeast bioassay, compounds with chain prenylation showed in general an agonistic mode of action toward hERα, whereas furan and pyran prenylation led to an antagonistic mode of action.

Prenylation and Backbone Structure of Flavonoids and Isoflavonoids from Licorice and Hop Influence Their Phase I and II Metabolism.

In vitro liver metabolism of 11 prenylated flavonoids and isoflavonoids was investigated by determining their phase I glucuronyl and sulfate metabolites using pork liver preparations. One hundred metabolites were annotated using RP-UHPLC-ESI-MS(n). A mass spectrometry-based data interpretation guideline was proposed for the tentative annotation of the position of hydroxyl groups, considering its relevance for estrogenic activity.

Involvement of a Hydrophobic Pocket and Helix 11 in Determining the Modes of Action of Prenylated Flavonoids and Isoflavonoids in the Human Estrogen Receptor.

Six prenylated (iso)flavonoids were purified from a licorice root extract and subjected to competition experiments with six commercially available (iso)flavonoids. The agonistic and antagonistic activities of these compounds towards both hERα (human estrogen receptor alpha) and hERβ were determined. Differences in the modes of action (agonist or antagonist) were observed for the various compounds tested.

Structural changes of 6a-hydroxy-pterocarpans upon heating modulate their estrogenicity.

The isoflavonoid composition of an ethanolic extract of fungus-treated soybean sprouts was strongly altered by a combined acid/heat treatment. UHPLC-MS analysis showed that 6a-hydroxy-pterocarpans were completely converted to their respective, more stable, 6a,11a-pterocarpenes, whereas other isoflavonoids, from the isoflavone and coumestan subclasses, were affected to a much lesser extent (loss of ∼15%). Subsequently, mixtures enriched in prenylated 6a-hydroxy-pterocarpans (pools of glyceollin I/II/III and glyceollin IV/VI) or prenylated 6a,11a-pterocarpenes (pools of dehydroglyceollin I/II/III and dehydroglyceollin IV/VI) were purified, and tested for activity on both human estrogen receptors (ERα and ERβ).