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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ECOM Separchrom PC01-HPLC Industrial Preparative Columns with Axial Compression

Separchrom PC01 ECOM industrial preparative columns correspond to the highest requirements of preparative liquid chromatography. They are designed to be used in a mode of axial compression with a moving input piston. 

<div style="display:block;" aria-labelledby="tab_item-0"><p><strong>HPLC Columns for prep chromatography. High performance columns with axial compression.</strong></p><p><strong>Separchrom PC01 ECOM</strong> <strong>columns</strong> correspond to the highest requirements of <strong>preparative liquid chromatography</strong>. They are designed to be used in a mode of axial compression with a moving input piston. In the original design, they are equipped with identical pistons on input and output (biaxial compression as an option). In the ECOM Separchrom PC FE modification, they have a fixed end plate on the output instead of the piston. Pistons and plates are equipped with frits. A liquid distributing system is installed under each frit. The design guarantees perfect piston flow, high efficiency even for high injection volume, and simple accessibility of frits for cleaning. Columns can be packed by dynamic slurry method or by sedimentation or with sorbent in a dry state.</p><p><strong>SEPARCHROM PC 01 ECOM columns</strong> are made of stainless steel AISI 316L (tube inner surface is polished to reach Ra &lt; 0.3 µm) with stainless steel pistons and UHMWPE (PTFE on the request) sealing rings. The stroke of the main piston is proportional to the used hydraulic cylinder or flange bolt length. Pistons are sectional; the frit (sintered mesh disc 3 µm pore size, 5 mm thickness) with the frit ring can be removed. The output plate in the FE version is made of UHMWPE, frit is fixed with a simple frit ring. Column flanges are not welded, but screwed onto the column tube. No temperature increase during manufacturing means no change in steel properties. The column stand made of stainless steel profiles is included for columns over 100 mm I.D.</p><p>Hydraulic cylinders fitted on the upper flange are offered with manual oil pumps as well as with fully automated electric motor-driven devices for column packing/unpacking procedures.</p><h3><strong>Accessories</strong></h3><p>Columns are offered with a broad scale of accessories such as filling adapters, slurry mixing vessels, slurry transporting pumps, etc.</p><h3><strong>COLUMN CONFIGURATION EXAMPLES</strong></h3><p>Columns are custom-made, do not hesitate to ask for any other sizes within the possible ranges</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ECOM_Separchrom_PC_01_HPLC_Column_available_configuration_part_1_1795482301.jpg" alt="ECOM: Separchrom PC01-HPLC Column - available configuration - part 1" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ECOM_Separchrom_PC_01_HPLC_Column_available_configuration_part_1_1795482301.jpg 236w," sizes="100vw" width="1440" height="952"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ECOM_Separchrom_PC_01_HPLC_Column_available_configuration_part_2_6d3198af67.jpg" alt="ECOM: Separchrom PC01-HPLC Column - available configuration - part 2" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ECOM_Separchrom_PC_01_HPLC_Column_available_configuration_part_2_6d3198af67.jpg 239w," sizes="100vw" width="1442" height="942"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ECOM_Separchrom_PC_01_HPLC_Column_available_configuration_part_3_9fd77a1054.jpg" alt="ECOM: Separchrom PC01-HPLC Column - available configuration - part 3" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ECOM_Separchrom_PC_01_HPLC_Column_available_configuration_part_3_9fd77a1054.jpg 245w," sizes="100vw" width="1435" height="315"></p></div>

ECOM Separchrom PC02-MPLC (Medium-pressure) Columns for Prep Chromatography

Industrial-scale Preparative Columns PC02 - Columns for medium-pressure with axial bed compression for prep chromatography.

<div style="display:block;" aria-labelledby="tab_item-0"><p><strong>ECOM Separchrom PC02 medium-pressure stainless steel columns are intended for separation where high pressure is not necessary, but good efficiency can still be expected. They are made of stainless steel tubes.</strong></p><p>Part of the column is an <strong>input piston made of ultra-high molecular weight polyethylene</strong> and it is equipped with <strong>stainless steel support</strong> and <strong>stainless steel mesh frit</strong>. Flow distributor with groves is incorporated into the piston to guarantee piston flow with nearly zero pressure drop. The design guarantees simple accessibility of frits for cleaning.</p><p>Columns can be <strong>packed by dynamic slurry method</strong>, or <strong>by sedimentation</strong>, or <strong>with sorbent in the dry state</strong>, both with <strong>silica</strong> and <strong>polymer sorbents</strong>. For soft polymer sorbents, ECOM Separchrom PC02 oil systems can be equipped with a special software application to compensate for the swelling and unswelling of sorbents in different mobile phases (the column piston is moved in very small steps up and down during use).</p><h3><strong>Materials</strong></h3><p>Medium pressure prep chromatography column ECOM SEPARCHROM PC 02 is made of AISI 316L stainless steel, UHMWE moving pistons are equipped with integral sealing wings. Frits (stainless steel mesh 5 µm pore size, 5 mm thickness) can be fixed with a stainless steel ring. The stand made of stainless steel profiles is included.</p><h3><strong>COLUMN CONFIGURATION EXAMPLES</strong></h3><p>Columns are custom-made, do not hesitate to ask for any other sizes within the possible ranges</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ECOM_Separchrom_PC_02_HPLC_Column_available_configuration_part_1_dfb61faf03.jpg" alt="ECOM: Separchrom PC02-HPLC Column - available configurations - part 1" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ECOM_Separchrom_PC_02_HPLC_Column_available_configuration_part_1_dfb61faf03.jpg 245w," sizes="100vw" width="1641" height="939"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ECOM_Separchrom_PC_02_HPLC_Column_available_configuration_part_2_cb9f807757.jpg" alt="ECOM: Separchrom PC02-HPLC Column - available configurations - part 2" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ECOM_Separchrom_PC_02_HPLC_Column_available_configuration_part_2_cb9f807757.jpg 245w," sizes="100vw" width="1645" height="364"></p></div>

ECOM Separchrom PC04-Non-metal Columns for Prep Chromatography

Industrial-scale preparative non-metal columns for prep chromatography with axial compression correspond to the highest requirements of preparative liquid chromatography. 

<div style="display:block;" aria-labelledby="tab_item-0"><p><strong>Polyethylene cartridge columns are usually intended for flash chromatography.</strong> We offer powerful<strong> ECOM Separchrom PC04 columns </strong>made of high-quality ultra-high molecular weight polyethylene, equipped with moving pistons and with no metal in contact with the mobile phase. Non-metal columns are required in biochromatography and some other special applications.</p><p>Plastic columns for preparative liquid chromatography <strong>ECOM SEPARCHROM PC 04</strong>, are unfilled, and made of ultra-high molecular weight polyethylene. They are equipped with the same pistons on the input and the output. The input piston is moved either by flange bolts (type A), or by a central stainless steel threaded rod (type B). The pistons are fitted with plastic polypropylene frits 10 µm and a distribution system.</p><h3><strong>COLUMN CONFIGURATION EXAMPLES</strong></h3><p>Columns are custom-made, do not hesitate to ask for any other sizes within the possible ranges</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ECOM_Separchrom_PC_04_HPLC_Column_available_configurations_8767eb40ae.jpg" alt="ECOM: Separchrom PC04-HPLC Column - available configurations" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ECOM_Separchrom_PC_04_HPLC_Column_available_configurations_8767eb40ae.jpg 245w," sizes="100vw" width="1645" height="823"></p></div>

ECOM ION-QN and ION-QD Chiral HPLC Columns

 Weak Anion-Exchanger (WAX) stationary phases for reliable chiral separation of organic acids and amino acids. The most efficient approach to purify and resolve even the most troublesome enantiomeric mixtures.

<p><strong>Weak Anion-Exchanger (WAX) stationary phases for reliable chiral separation of organic acids and amino acids.&nbsp;</strong></p><p>We introduce our own generic series of weak anion-exchangers, based on <strong>tert-butyl-carbamoylated Cinchona alkaloids quinine (QN)</strong> and <strong>quinidine (QD)</strong>. Our Chiral ION-QN and Chiral ION-QD columns contain a well-balanced pair of pseudoenantiomeric chiral selectors, designed to efficiently separate enantiomers of acidic compounds. These columns represent the most efficient approach to purify and resolve even the most troublesome enantiomeric mixtures.</p><h4><strong>Applications</strong></h4><ul><li>Chiral ION-QN and Chiral ION-QD are ideal for enantioseparations of chiral acidic compounds, including:</li><li>N-protected amino acids</li><li>Aminophosphonic &amp; Aminosulfonic acids</li><li>Lactic &amp; Thiolactic acids</li><li>Clenbuterol &amp; Thyroxine</li></ul><h4><strong>Key Benefits</strong></h4><ul><li>Provide better separation power and increased enantioselectivity (in comparison to other available alternatives)</li><li>Allow elegant switch of the elution order of enantiomers</li><li>Demonstrated high stability against all common HPLC solvents</li><li>Enable enhanced method development</li><li>Available at analytical and preparative scale</li></ul><h4><strong>Columns</strong></h4><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ECOM_Chiral_HPLC_Column_ION_QN_and_ION_QD_6_085a58fc5e.jpg" alt="ECOM: Chiral HPLC Column ION-QN and ION-QD" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ECOM_Chiral_HPLC_Column_ION_QN_and_ION_QD_6_085a58fc5e.jpg 245w," sizes="100vw" width="1059" height="531"></p><h4><strong>Features&nbsp;</strong></h4><ul><li><strong>Max. pressure</strong>: 5800 psi (400 bar)</li><li><strong>Particle size</strong>: 3 or 5 μm</li><li><strong>pH range</strong>: 2 to 9</li><li><strong>Pore size</strong>: 120 Å</li><li><strong>Surface area</strong>: 300 m²/g</li><li><strong>Max. temperature</strong>: 60 °C</li><li><strong>Packing material</strong>: Spherical, Fully Porous</li><li><strong>Carbon load</strong>: 13.0 %</li><li><strong>End-capped</strong>: Yes</li><li><strong>Product line</strong>: ION</li></ul><p>The mobile phase composition (methanol-formic acid-ammonium formate) has been optimized for preparative applications to provide high column loadability, fast analyte elution, and good peak shape. Moreover, the buffer allows for simple product harvesting by solvent evaporation and subsequent ammonium formate sublimation 50 °C / 10 torr.</p><p>The anion exchangers are perfect for the purification of organic acids and their chiral separation. They are very efficient in the chiral resolution of amino acids, but also other derivatives, such as amino phosphonic acids. Aminophosphonic acids are important precursors in the synthesis of phosphopeptidomimetics, which may potentially serve as new-generation pharmaceuticals.</p>

Products from category HPLC columns focused on Consumables distributed by ECOM spol. s r.o. - page 1

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New blood biomarkers reveal how faithfully diabetes patients take metformin

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