EU Regulation 396/2005: Pesticide Residue Testing and the Critical Role of QuEChERS Evaporation in Food Safety

<div><div><p><strong>Researchers led by </strong><a target="_blank" rel="noopener noreferrer" href="https://kudova.group.uochb.cz/en"><strong>Eva Kudová</strong></a><strong> from IOCB Prague and Jitka Viktorová from UCT Prague have identified new androstane-based steroid derivatives that can significantly improve the effectiveness of existing antibiotics against multidrug-resistant </strong><i><strong>Staphylococcus aureus</strong></i><strong>.</strong></p></div></div><div><p>The team screened dozens of natural steroidal hormones and synthetic derivatives to see whether they could block bacterial efflux pumps – mechanisms that bacteria use to eject antibiotics and survive treatment. Two compounds emerged as particularly promising: they inhibited efflux pumps and lowered the effective doses of antibiotics such as ciprofloxacin and erythromycin.</p><p>Further analysis showed that one of the compounds also suppressed genes linked to bacterial virulence. Another key finding is that the most active molecules are non-toxic to human immune cells and showed no detectable endocrine activity, suggesting a favorable safety profile.</p><p>These findings support the idea that rationally designed steroid-based molecules could act as antibiotic adjuvants, helping existing drugs overcome bacterial resistance.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/IOCB_Prague_Steroidal_hormones_and_neurosteroids_novel_therapeutic_strategies_in_bacterial_infections_8e5d2a7b48.jpg" alt="IOCB Prague: Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_IOCB_Prague_Steroidal_hormones_and_neurosteroids_novel_therapeutic_strategies_in_bacterial_infections_8e5d2a7b48.jpg 222w," sizes="100vw" width="1258" height="886"></p><blockquote><h4><strong>Original Article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://www.sciencedirect.com/science/article/pii/S0223523426001613?via%3Dihub"><strong>Steroidal hormones and neurosteroids - novel therapeutic strategies in bacterial infections: Design, synthesis, and biological evaluation</strong></a></h4><p>Daniela Brdová, Bára Křížkovská, Jan Špaček, Zdeněk Míchal, Eva Jablonská, Ondřej Strnad, Hana Chodounská, Eszter Szánti-Pintér, Marina Morozovová, Václav Hanžl, Jan Tkadlec, Martijn Riool, Jan Lipov, Jitka Viktorová, Eva Kudová&nbsp;</p><p><i><strong>Eur. J. Med. Chem., 2026, 308, 118716</strong></i></p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1016/j.ejmech.2026.118716">https://doi.org/10.1016/j.ejmech.2026.118716</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><h4><strong>Abstract</strong></h4><p>The global rise of antibiotic resistance necessitates novel therapeutic strategies for infectious diseases. Inhibition of bacterial efflux pumps, which contribute to multidrug resistance, represents a promising approach to restore or even increase the efficacy of existing antibiotics. Using fluorescence-based ethidium bromide accumulation, broth microdilution, and checkerboard assays, we evaluated 26 endogenous steroidal hormones and neurosteroids, along with 30 synthetic derivatives, for their ability to enhance antibiotic susceptibility in multidrug-resistant <i>Staphylococcus aureus</i>. Structure-activity relationship analysis identified compounds <strong>13</strong> and <strong>16</strong> as lead candidates, exhibiting strong efflux pump inhibition and marked reductions in the minimum inhibitory concentrations of ciprofloxacin and erythromycin. Both compounds showed additive effects in checkerboard assays. Modifications at C-3 (polar substitution) and C-17 (3α,5β-stereochemistry and nonpolar substitution) were essential for potent efflux inhibition and sensitization, although these modifications were not additive when combined. Transcriptome analysis further revealed that compound <strong>13</strong> significantly downregulated <i>S. aureus</i> virulence-associated genes when administered alone or in combination with antibiotics. Cytotoxicity assessment in human peripheral blood mononuclear cells and receptor transactivation assays for estrogen, androgen, and progesterone receptors indicated that the most active derivatives were non-toxic and lacked detectable endocrine activity, suggesting a favorable safety profile. Overall, these findings support the concept that rationally designed andostane-based steroidal scaffolds can function as competitive bacterial efflux pump inhibitors and serve as potential antibiotic adjuvants to mitigate efflux-mediated resistance.</p><h4><strong>Instrumentation</strong></h4><h5><strong>Structural characterization</strong></h5><ul><li><strong>AVANCE III 400 MHz NMR spectrometer</strong> (Bruker)</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=3&amp;search=LTQ+Orbitrap+XL"><strong>LTQ Orbitrap XL HRMS</strong></a> (Thermo Fisher Scientific, ESI)</li></ul></div>

Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections

<p><strong>Metformin is currently the first-line oral drug of choice for the treatment of type 2 diabetes. It reduces glucose production in the liver, improves tissue sensitivity to insulin, and does not cause weight gain or hypoglycemia, which sets it apart from some other antidiabetic drugs. Moreover, its long-term beneficial effects on the risk of cardiovascular complications and mortality in people with type 2 diabetes have been well established. Researchers from the Institute of Physiology CAS (IPHYS) have identified a new group of blood metabolites that could help physicians objectively monitor whether patients with type 2 diabetes are taking their metformin as prescribed.</strong></p><h4><strong>New biomarkers for metformin use</strong></h4><p>A team led by Tomáš Čajka from the Laboratory of Translational Metabolism at IPHYS analyzed plasma samples from <strong>637 patients with type 2 diabetes treated with metformin</strong> and <strong>143 non-diabetic controls</strong> using advanced metabolomics and lipidomics. Among 614 detected metabolites, they identified five from the group of <strong>N-lactoyl-amino acids </strong>(e.g. N‑lactoyl-phenylalanine), which had previously been seen as unknown signals due to missing reference spectra in databases. The levels of these metabolites in the blood closely reflected the plasma concentrations of metformin. In patients with the highest metformin exposure, the concentrations of these metabolites were up to 7.2 times higher than in controls.</p><h4><strong>A sensitive “fingerprint” of the drug’s effect</strong></h4><p>N-Lactoyl-amino acids are formed in cells by combining lactate and amino acids, thus reflecting the metformin-induced changes in cellular energy metabolism. “<i>Importantly, even though they occur in plasma only at nanomolar concentrations, they reliably distinguish patients who take metformin regularly from those who take it irregularly or not at all</i>,” emphasizes T. Čajka.</p><h4><strong>Metabolomics in practice and international collaboration</strong></h4><p>The study also provides a detailed description of broader metabolic changes in type 2 diabetes, including increases in lactate, organic acids, and branched-chain amino acids, as well as extensive remodelling of the lipid profile. In addition to T. Čajka’s team, collaborators from the Institute for <strong>Clinical and Experimental Medicine in Prague</strong> and the <strong>West Coast Metabolomics Center</strong> (University of California, Davis) also participated in the study.</p><p>The results demonstrate that advanced metabolomics approaches developed at IPHYS within the <strong>CarDia project</strong> can find highly practical applications both in clinical studies and in personalized monitoring of treatment in patients with diabetes.</p><blockquote><h4><strong>The original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://ascpt.onlinelibrary.wiley.com/doi/10.1002/cpt.70205"><strong>Untargeted Metabolomics Identifies N-Lactoyl-Amino Acids as Dose-Responsive Plasma Biomarkers of Metformin Adherence in Type 2 Diabetes</strong></a></h4><p>Tomas Cajka, Jiri Hricko, Lucie Rudl Kulhava, Michaela Paucova, Michaela Novakova, Veronika Hola, Stanislava Rakusanova, Oliver Fiehn, Vojtech Skop, Ivana Lankova, Iva Miskova, Terezie Pelikanova, Martin Haluzik</p><p>Clin Pharmacol Ther, 119: 1057-1069</p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1002/cpt.70205">https://doi.org/10.1002/cpt.70205</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><h4><strong>Abstract</strong></h4><p>Metformin is the most widely prescribed antidiabetic drug, yet adherence remains difficult to objectively assess. Using untargeted metabolomics and lipidomics, we analyzed plasma from 637 patients with type 2 diabetes (T2D) with confirmed metformin use and 143 nondiabetic controls, annotating 614 metabolites. Patients were stratified by plasma metformin into sub-therapeutic, therapeutic, and supra-therapeutic groups, and associations were evaluated by multiple linear regression and composite metabolite ranking. Five previously unannotated features were structurally identified as N-lactoyl-amino acids, whose levels correlated strongly with plasma metformin (ρ = 0.42–0.55, P &lt; 0.0001) and increased up to 7.2-fold in the supra-therapeutic group (&gt; 2000 ng/mL). While N-lactoyl-amino acids were consistently detected in the nanomolar range, they still displayed robust and dose-dependent associations with metformin. Broader metabolic changes in T2D included elevated lactate, organic acids, and branched-chain amino acids, together with reduced urea cycle metabolites. Lipidomics showed increases in saturated triacylglycerols and diacylglycerols and decreases in cholesteryl esters, sphingomyelins, and phospholipids. These findings establish N-lactoyl-amino acids as robust, dose-responsive plasma biomarkers of metformin exposure. Despite being up to four orders of magnitude less abundant than their amino acid precursors, they sensitively reflect mitochondrial lactate overflow and pharmacodynamic adaptation, offering objective assessment of adherence.</p>

New blood biomarkers reveal how faithfully diabetes patients take metformin

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The Czech Academy of Sciences (CAS) was established by Act No. 283/1992 Coll. as the Czech successor of the former Czechoslovak Academy of Sciences. It is set up as a complex of 54 public research institutions.

Czech Academy of Sciences

The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague) is a leading scientific institution in the Czech Republic, recognized internationally. Its primary mission is basic research in the fields of chemical biology and medicinal chemistry, organic and material oriented chemistry, chemistry of natural compounds, biochemistry and molecular biology, physical chemistry, theoretical chemistry, and analytical chemistry. 

Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences

Organomation, founded in 1959, designs and manufactures high-quality nitrogen evaporators and extraction systems. Known for innovation and durability, their lab instruments are used globally for efficient sample preparation with strong customer support.

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Thermo Scientific Dionex AutoTrace 280 Solid-Phase Extraction Instrument

Extract analytes of interest from large volume aqueous samples easily and efficiently with the Thermo Scientific™ Dionex™ AutoTrace™ 280 Solid-Phase Extraction (SPE) Instrument.

<p><strong>Extract analytes of interest from large volume aqueous samples easily and efficiently with the Thermo Scientific™ Dionex™ AutoTrace™ 280 Solid-Phase Extraction (SPE) Instrument.&nbsp;</strong></p><p>The AutoTrace 280 automates all four steps of SPE (conditioning, loading, rinsing, and eluting), reducing solvent consumption and improving recovery and reproducibility. Boost productivity and reduce cost of analysis by simultaneously processing up to six samples in 2-3 hours with only 15 minutes of operator involvement. The AutoTrace 280 meets requirements in US EPA methods including the 500 and 600 series.</p><h5><strong>Improved reliability and recovery</strong></h5><ul><li>Automated SPE minimizes operator intervention</li><li>Positive pressure loading and elution of samples and solvents provide constant flow for improved analytical precision</li></ul><h5><strong>Flexibility in operation</strong></h5><ul><li>Loads sample volumes from 20 mL to 4 L</li><li>Compatible with 1, 3, and 6 mL cartridges and with 47 mm SPE disks</li><li>Automatically conditions, rinses, and elutes SPE cartridges with a choice of five solvents</li><li>Offers a choice of six different collection vial racks</li></ul><h5><strong>Improved laboratory safety</strong></h5><ul><li>Minimal sample handling reduces operator exposure to hazardous chemicals</li><li>No hood required</li></ul><h5><strong>Enhanced laboratory productivity and reduced costs</strong></h5><ul><li>Unattended operation</li><li>Batch processing of up to 6 samples</li><li>Reduced solvent usage</li><li>Segregates aqueous and solvent waste using separate waste lines for efficient, cost-effective waste handling</li></ul><h5><strong>Supports a range of matrices and applications</strong></h5><ul><li>Ability to process samples containing suspended solids</li><li>Meets requirements for solid-phase extraction for U.S. EPA methods including 500 and 600 series</li></ul><h5><strong>Recommended use</strong></h5><ul><li>Analyze prepared samples with Thermo Scientific LC or GC systems for a fully integrated workflow</li></ul><h4><strong>Specifications</strong></h4><ul><li><strong>Instrument Type:</strong> Automated Solid Phase Extraction (SPE) System</li><li><strong>Application:</strong> For use with 47 mm SPE disks</li><li><strong>Model Description:</strong> AutoTrace 280 SPE System</li></ul><h5><strong>Performance &amp; Operating Details</strong></h5><ul><li><strong>Disk Compatibility:</strong> Designed for 47 mm SPE disks</li><li><strong>Pressure Range:</strong><ul><li>Output: 0 to 30 psi (0 to 1.4 bar)</li><li>Input: Up to 100 psi (6.9 bar) maximum</li></ul></li><li><strong>Voltage:</strong> 100–240 V ±10%</li><li><strong>Frequency:</strong> 47–63 Hz</li></ul><h5><strong>Physical Specifications</strong></h5><ul><li><strong>Dimensions (D × W × H):</strong> 57 × 63.5 × 69 cm</li><li><strong>Unit Size:</strong> Each</li></ul>

Thermo Scientific EXTREVA ASE Accelerated Solvent Extractor

Achieve true walkaway sample-to-vial sample preparation with the Thermo Scientific™ EXTREVA™ ASE™ Accelerated Solvent Extractor. 

<p><strong>Achieve true walkaway sample-to-vial sample preparation with the Thermo Scientific™ EXTREVA™ ASE™ Accelerated Solvent Extractor. Without any intervention, perform sample extraction, in-cell cleanup and evaporation—all in one seamless operation—reducing manual labor from hours to minutes and enabling you to focus on other lab priorities while using up to 50% less solvent than other sample preparation techniques.</strong></p><p><strong>Accelerate your journey from sample to vial</strong></p><h5><strong>The EXTREVA ASE Accelerated Solvent Extractor offers:</strong></h5><ul><li><strong>All-in-one sample preparation.</strong> The EXTREVA ASE system automatically extracts and concentrates samples, eliminating the need to manually move sample extracts to another device for solvent evaporation.</li><li><strong>A walk-away solution. </strong>The system minimizes hands-on sample preparation tasks, enabling staff to accomplish other tasks.</li><li><strong>Parallel extraction. </strong>One EXTREVA ASE system can perform four parallel sample extractions, substantially increasing throughput.</li><li><strong>Gas-assisted extraction. </strong>The dynamic gas-assisted extraction mode reduces solvent consumption to between 5 and 100 milliliters per sample in most cases.</li><li><strong>Automation. </strong>Full automation improves recoveries and reproducibility while reducing training needs. Unlike humans, automated systems are ideal for performing the same tedious task repeatedly, and they don’t make mistakes.</li><li><strong>Method flexibility and optimization</strong>. Up to six different solvents can be used, including wash solvents for cleaning between methods. Precise flow control optimizes methods.</li><li><strong>Barcode-reading.</strong> The system tracks sample information and preparation parameters using a 2-D bar code reader to facilitate tracking and integrity. Data is recorded on the instrument or Thermo Scientific™ <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/76"><strong>Chromeleon™ Chromatography Data System (CDS) software</strong></a>.</li></ul><h4><strong>Specifications</strong></h4><ul><li><strong>Instrument Type:</strong> Automated Sample Preparation System</li><li><strong>Application:</strong> Simultaneous sample extraction and concentration</li><li><strong>Model Description:</strong> EXTREVA ASE Extraction and Evaporation System</li></ul><h5><strong>Performance &amp; Capabilities</strong></h5><ul><li><strong>Extraction Temperature Range:</strong> 40–200 °C</li><li><strong>Evaporation Temperature Range:</strong> 40–100 °C</li><li><strong>Compatible Solvents:</strong> Wide range of organic and aqueous solvents</li><li><strong>Pressure Capability:</strong> Up to 200 psi</li><li><strong>Power Consumption:</strong> 2000 W</li><li><strong>Frequency:</strong> 50/60 Hz</li></ul><h5><strong>Sample &amp; Solvent Handling</strong></h5><ul><li><strong>Extraction Cells (stainless steel):</strong> 1, 5, 10, 22, 34, 66, 100 mL</li><li><strong>Extraction Cell Tray:</strong> 16-position with 1 rinse</li><li><strong>Collection Vials:</strong><ul><li>60 mL and 100 mL evaporation vials</li><li>250 mL evaporation bottles</li><li>Direct concentrate to 2 mL sample vials with rinse capability</li></ul></li><li><strong>Collection Vial Tray:</strong> 16-position tray insert for 60 mL vials and 250 mL bottles; includes 4 rinse positions</li></ul><h5><strong>Utilities &amp; Requirements</strong></h5><ul><li><strong>Pneumatic Requirements:</strong><ul><li>Air: 130–140 psi</li><li>Nitrogen: 350–450 psi</li></ul></li></ul><h5><strong>Physical Specifications</strong></h5><ul><li><strong>Dimensions (D × W × H):</strong> 65.2 × 100 × 88.6 cm (25.6 × 39.4 × 34.8 in.)</li><li><strong>Weight:</strong> 160 kg (353 lb)</li><li><strong>Unit Size:</strong> Each</li></ul>

Thermo Scientific™ Dionex™ ASE™ 350 Accelerated Solvent Extractor

Save time, reduce solvent consumption, and boost productivity with Thermo Scientific™ Dionex™ ASE™ 350 Accelerated Solvent Extractor.

<div><p><strong>Automate extraction, filtration and clean up of compounds from solid and semisolid samples in minutes using the automated Thermo Scientific™ Dionex™ ASE™ 350 Accelerated Solvent Extractor. This system accommodates sample sizes of 1-100g, allows unattended extraction of up to 24 samples and uses 50 to 90% less solvent compared to other methods.&nbsp;</strong></p><p>The chemically inert pathway supports acid and alkaline sample matrices and solvents. Flexible, easy-to-operate and cost-effective, the Dionex ASE 350 is ideally suited for high-throughput laboratories and for a wide variety of applications.</p><div><h4><strong>Rapid and efficient extractions</strong></h4><ul><li>Elevated temperature (up to 200°C) and pressure (1500psi) reduce extraction times and solvent consumption</li><li>Fast pump (70mL/min.) enables fast extractions (typically 12-20 minutes)</li><li>Specialized oven design ensures precise temperature control for excellent reproducibility</li><li>Integrated solvent controller allows mixing and delivery of up to three solvents</li><li>The <strong>Thermo Scientific™ SmartRun™ System</strong> ensures cell size and collection vessel size are matched for an optimal extraction</li></ul><h4><strong>Enhanced flexibility to support multiple applications</strong></h4><ul><li>System accommodates <strong>1, 5, 10, 22, 34, 66 </strong>and <strong>100mL cell sizes</strong></li><li>pH-hardened pathway with <strong>Thermo Scientific™ Dionium™ components and cell</strong> enables compatibility with acid or alkaline pretreated matrices</li></ul><h4><strong>Dramatically reduced solvent consumption</strong></h4><ul><li>Requires less than 50mL solvent for a 20g sample</li><li>Includes solvent saver mode for further solvent savings</li></ul><h4><strong>Enhanced laboratory productivity</strong></h4><ul><li>System holds up to 24 samples for unattended operation</li><li>Flow-through technology allows in-line filtration and in-cell cleanup</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Dionex_ASE_350_system_2_9426ff3f9a/Thermo-Scientific-Dionex-ASE-350-system_2.jpg" alt="Thermo Scientific™ Dionex™ ASE™ 350 Accelerated Solvent Extractor" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Dionex_ASE_350_system_2_9426ff3f9a/thumbnail_Thermo-Scientific-Dionex-ASE-350-system_2.jpg 114w," sizes="100vw" width="579" height="792"></p><h3><strong>🛠️ Specifications</strong></h3><ul><li><strong>Collection Vial Tray</strong>: 26-position tray insert for 60 mL vials; 19-position tray insert for 250 mL bottles</li><li><strong>Depth (English)</strong>: 27.3 in.</li><li><strong>Depth (Metric)</strong>: 69.3 cm</li><li><strong>Description</strong>: Extractor Only</li><li><strong>Extraction Fluids</strong>: Compatible with a wide range of organic and aqueous solvents</li><li><strong>Fluid Sensors</strong>: IR</li><li><strong>Frequency</strong>: 50/60 Hz</li><li><strong>Height (English)</strong>: 24.3 in.</li><li><strong>Height (Metric)</strong>: 61.7 cm</li><li><strong>Pneumatic Requirements</strong>: Air at 400–827 kPa (60–120 psi); N2 (at 1034 ×–1340 kPa (150–200 psi))</li><li><strong>Power Consumption</strong>: 500 Max VA</li><li><strong>Pressure</strong>: 10 MPa (1500 psi)</li><li><strong>Pump Flow</strong>: 70 mL/min</li><li><strong>Temperature Control</strong>: Up to 200 °C</li><li><strong>Weight (English)</strong>: 140 lb.</li><li><strong>Weight (Metric)</strong>: 65 kg</li><li><strong>Width (English)</strong>: 26.5 in.</li><li><strong>Width (Metric)</strong>: 67.3 cm</li><li><strong>Collection Vials</strong>: 60, 250 mL</li><li><strong>Dimensions (D x W x H)</strong>: 69.3 x 67.3 x 61.7 cm</li><li><strong>Extraction Cell Tray</strong>: 24 Cell, 2 Rinse</li><li><strong>Extraction Cells</strong>: 1, 5, 10, 22, 34, 66, 100 mL</li><li><strong>For Use With (Equipment)</strong>: Dionex ASE 350</li><li><strong>Type</strong>: Dionex ASE 350 System</li><li><strong>Unit Size</strong>: Each</li></ul></div></div>

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