<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>Wiley, a global leader in authoritative content and research intelligence for the advancement of scientific discovery, innovation and learning, today announced the release of additional data to its IR and Raman spectral libraries, significantly broadening compound coverage, including materials, polymers, minerals, and others.</strong></p><p>This latest release includes the first installment of Raman spectra from <strong>Wiley's collaboration with the American Museum of Natural History (AMNH), announced earlier this spring</strong>, drawing from one of the world's most important mineral collections.</p><p>“<i>Researchers depend on reference data as a foundation for sound scientific decisions</i>,” said Graeme Whitley, senior director, data science solutions at Wiley. “<i>Continuous updates ensure scientists always have the most current, reliable reference libraries at their fingertips, helping them work faster and make confident decisions when it matters most.</i>”</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Wiley_Wiley_expands_its_trusted_IR_and_Raman_spectral_library_collections_helping_analytical_labs_make_faster_more_confident_decisions_1a54aaad3a.jpg" alt="Wiley: Wiley expands its trusted IR and Raman spectral library collections—helping analytical labs make faster, more confident decisions" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Wiley_Wiley_expands_its_trusted_IR_and_Raman_spectral_library_collections_helping_analytical_labs_make_faster_more_confident_decisions_1a54aaad3a.jpg 245w," sizes="100vw" width="1600" height="856"></p><h4><strong>Summary of updates:</strong></h4><h5><strong>KnowItAll Raman Spectral Library Collection</strong></h5><ul><li><strong>Added: </strong>1,213 spectra</li><li><strong>Now contains: </strong>29K+ spectra</li></ul><p><strong>2 new databases:</strong></p><ul><li>Raman – American Museum of Natural History Minerals – Wiley – 198 spectra</li><li>Raman – Microbiology – 71 spectra</li></ul><p><strong>Spectra added to databases:</strong></p><ul><li>Raman – Consumer Goods &amp; Food-Related Compounds – +104</li><li>Raman – Drugs – +128</li><li>Raman – Materials – +132</li><li>Raman – Minerals – +233</li><li>Raman – Polymers – +5</li><li>Raman – Pigments &amp; Dyes – +342</li></ul><h5><strong>KnowItAll IR Spectral Library Collection</strong></h5><ul><li><strong>Added: </strong>949 spectra</li><li><strong>Now contains: </strong>344K+ spectra</li></ul><p><strong>7 new databases:</strong></p><ul><li>ATR-IR – Clinical – 364 spectra</li><li>ATR-IR – Materials – 10 spectra</li><li>ATR-IR – Pigments &amp; Dyes – 420 spectra</li><li>ATR-IR – Polymers – 21 spectra</li><li>IR – Clinical – 20 spectra</li><li>IR – Materials – 17 spectra</li><li>IR – Microbiology – 75 spectra</li></ul><p><strong>Spectra added to databases:</strong></p><ul><li>IR – Minerals – +5</li><li>IR – Polymers – +17</li></ul><p>Spectral library subscribers automatically gain access to new data, ensuring labs always have the most current, reliable reference libraries to improve analysis, reduce errors, and increase productivity.</p><ul><li>Learn more at: <a target="_blank" rel="noopener noreferrer" href="https://sciencesolutions.wiley.com/spectral-databases/"><strong>www.sciencesolutions.wiley.com/spectral-databases</strong></a></li><li>Existing subscribers can access step-by-step guidance on updating their KnowItAll databases at <a target="_blank" rel="noopener noreferrer" href="https://sciencesolutions.wiley.com/how-to-update-knowitall-databases"><strong>https://sciencesolutions.wiley.com/how-to-update-knowitall-databases</strong></a></li></ul><h5><strong>Wiley Spectral Databases</strong></h5><p>Wiley's spectral databases are consistently evolving to meet today's research demands, covering multiple spectral techniques across a wide range of applications including polymers, materials, environmental, forensics, toxicology, pharmaceutical, biotech, automotive, aerospace, food, cosmetics, and more. Built on rigorous quality protocols, Wiley delivers industry-leading spectral data and intelligent tools to accelerate analysis and deliver deeper insights — making it the authoritative, trusted source that analytical labs worldwide rely on.&nbsp;</p><h5><strong>About Wiley</strong></h5><p>Wiley (NYSE: WLY) is a global leader in authoritative content and research intelligence for the advancement of scientific discovery, innovation, and learning. With more than 200 years at the center of the scholarly ecosystem, Wiley combines trusted publishing heritage with AI-powered platforms to transform how knowledge is discovered, accessed, and applied. From individual researchers and students to Fortune 500 R&amp;D teams, Wiley enables the transformation of scientific breakthroughs into real-world impact. From knowledge to impact—Wiley is redefining what's possible in science and learning.&nbsp;</p>

Wiley expands its trusted IR and Raman spectral library collections

<p><strong>Our Library never stops expanding. What are the most recent contributions to LabRulezICPMS Library in the week of 4th May 2026? Check out new documents from the field of spectroscopy/spectrometry and related techniques!</strong></p><blockquote><p><span style="font-size:20px;">👉 </span><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library"><span style="font-size:20px;"><strong>SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT SPECTROSCOPY/SPECTROMETRY RELATED TECHNIQUES</strong></span></a></p></blockquote><blockquote><p><strong>👉 Need info about different analytical techniques?</strong> Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library"><strong>LabRulezLCMS</strong></a> or <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library"><strong>LabRulezGCMS</strong></a> libraries.</p></blockquote><p>This week we bring you application notes by<strong> KNAUER, Shimadzu, </strong>and <strong>Thermo Fisher Scientific!</strong></p><h3><strong>1. KNAUER: Analysis of HPLC fractions by Benchtop NMR</strong></h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/labrulez-bucket-strapi-h3hsga3/knauer_hplc_benchtop_nmr_web_638c60e13c.pdf"><strong>Full PDF for download</strong></a></li></ul><p>Preparative HPLC is essential for isolating compounds and removing impurities in pharmaceutical and chemical industries. Non-destructive, fast analysis is preferred to maintain yield and enable at-line monitoring, avoiding lengthy sample preparation. Recent advancements in benchtop NMR spectrometers (up to 90 MHz) allow quick analysis without deuterated solvents. In this proof-of-concept study we purified a pharmaceutical sample via HPLC and confirmed its identity using benchtop NMR. Fractions (0.7–4.4 mM) were analyzed without preparation, using only 300 µL per sample, ensuring rapid batch control with no product loss. This study demonstrates the seamless integration of HPLC and benchtop NMR.</p><h4><strong>Experimental</strong></h4><h5><strong>Preparative HPLC Method</strong></h5><p>Eluent 20:80 Ethanol/water, isocratic mode, flow rate 12.5 ml/min, detection UV254 nm 2 Hz, 500 µl stacked injection, automated fractionation with threshold function, column temperature ambient, Column Eurospher II 100-10 C18 150x20 mm&nbsp;</p><h5><strong>Analytical HPLC Method</strong></h5><p>Eluent 20:80 Ethanol /water + 0.1% formic acid, isocratic mode, flow rate 1 ml/min, detection UV254 nm 10 Hz, 5 µl partial loop injection, column temperature 25 °C, Column <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1633"><strong>Eurospher II 100-5 C18</strong></a> 150x4 mm&nbsp;</p><h5><strong>NMR Method&nbsp;</strong></h5><p>NMR spectra were acquired on a <strong>Magritek Multi-X Ultra 80 MHz benchtop NMR system</strong> using an adapted WET sequence for solvent suppression. 32 scans were acquired with a repetition time of 15s. WET parameters were adjusted for each sample to yield optimal suppression for all solvent signals. Pooled HPLC fractions were analysed directly without addition of deuterated solvents or other sample preparation.</p><h4><strong>Conclusion</strong></h4><p>This proof-of-concept study successfully shows that HPLC and benchtop NMR can be used together easily. Samples can be analyzed non-destructively within minutes and without any further preparation due to highly efficient suppression of multiple solvent signals. Compounds can be identified without the need of reference standards. This study shows that NMR can provide a valid compatible alternative detector for HPLC fraction analysis.</p><h3><strong>2. Shimadzu: DIC Analysis in High-Speed Tensile Test of CFRP</strong></h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00854_en_fb6c68b858.pdf"><strong>Full PDF for download</strong></a></li></ul><h4><strong>User Benefits</strong></h4><ul><li>The <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library?mainauthorItems=1&amp;search=HPV-X3"><strong>HPV-X3</strong></a> is suitable for observation of fracture of brittle materials such as CFRP because it has a maximum recording speed (framerate) of 20 Mfps.&nbsp;</li><li>The HPV-X3 provides improved DIC analysis performance, as its resolution is 3 times higher than that of the conventional highspeed video camera.</li><li>The HITS-TX impact testing machine enables testing at a maximum speed of 20 m/s</li></ul><p>Carbon fiber reinforced plastic (CFRP) is a material with particularly high specific strength, even among composite materials, and used in various applications such as transport aircraft, taking advantage of its excellent mechanical properties. Because CFRP consists of carbon fibers and resin, it shows complex fracture behavior, and brittle fracture progresses from damage as the point of origin. Since fracture proceeds instantaneously, a high-speed video camera with a high recording speed is necessary when observing fracture of CFRP. One method for measuring strain in a high-speed tensile test is Digital Image Correlation (DIC), which visualizes the distribution of strain at the specimen surface by comparing a random pattern on the specimen surface before and after deformation. Thus, a high-speed video camera with a high resolution is also necessary in order to improve the DIC performance.&nbsp;</p><p>Newly-developed <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library?mainauthorItems=1&amp;search=HPV-X3"><strong>Hyper Vision HPV-X3 high-speed video camera</strong></a> is extremely well-suited to DIC analysis of CFRP, as its recording speed is 2 timesfaster and itsresolution is 3 times higher than the conventional HPV-X2. In this experiment, a high-speed tensile test of CFRP was conducted using a HITS-TX high-speed tensile testing machine. The condition of the test was observed with the new HPV-X3, and the strain distribution of the CFRP test piece was clarified by a DIC analysis of the recorded images.</p><h4><strong>Test Piece and Test Instruments</strong></h4><p>A CFRP quasi-isotropic laminate was used as the test piece. Aluminum foil was glued to the back side of the test piece, and the timing when the electrical conduction of the aluminum foil was interrupted by fracture of the test piece was used as the trigger for video recording. The HITS-TX was used in the highspeed tensile test. The HPV-X3 was used in fracture observation, and for comparison, the fracture process was also recorded with the conventional HPV-X2 camera. Fig. 1 shows the condition of the test, and Table 1 and Table 2 show the equipment composition and test conditions, respectively.</p><h4><strong>DIC Analysis Results in High-Speed Tensile Test</strong></h4><p>Fig. 3 shows the DIC analysis results in the high-speed tensile test. The color bar was set to display the color purple at around 0 % strain and red at around 2 % strain. Fig. 3 (1) is an image at the start of the test. After the test started, strain in the 45˚ direction concentrated from the lower left to the right central area, as can be seen in Fig. 3 (2). Then, as the test progressed, a condition of increasing strain in the initial area of strain concentration can be seen in Fig. 3 (3) to (9). A crack occurs in Fig. 3 (10), and strain decreases in the crack area. Following this, the test piece fractured completely in Fig. 3 (11) and (12), and a decrease in the strain in the area around the crack could be observed.</p><h4><strong>Conclusion</strong></h4><p>A high-speed tensile test of CFRP was conducted using a HITSTX high-speed tensile testing machine and the newlydeveloped HPV-X3 high-speed video camera, and the strain distribution at the time of test piece fracture was visualized by a DIC analysis. Because the HPV-X3 offers a 3 times higher resolution and a 2 times faster recording speed than the conventional device, it is a suitable high-speed video camera for fracture observation and DIC analysis in impact tests of brittle materials such as CFRP. The measurement system introduced in this Application News article is a useful tool for the development of composite materials.</p><h3><strong>3. Thermo Fisher Scientific: Polymer analysis using femtosecond-laser-ablation depth profiling</strong></h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/labrulez-bucket-strapi-h3hsga3/xps_depth_profiling_polymer_analysis_appnote_c731e2e7e0.pdf"><strong>Full PDF for download</strong></a></li></ul><p>X-ray photoelectron spectroscopy (XPS) is an essential polymer characterization technique that can identify not just the elemental composition but also the chemical state of polymer samples. This allows the chemical bonding environment to be deduced and, as a result, the polymer species can be identified. This can all be achieved with minimal sample preparation thanks to the built-in charge-compensation systems found in XPS instruments, which simplify the analysis of insulating samples.&nbsp;</p><p>The introduction of gas cluster ion sources (GCIS), such as the Thermo Scientific™ MAGCIS Dual Mode Ion Source, marked a major step forward in polymer analysis. Unlike monatomic ion beams, GCIS are able to clean surface contamination, and etch away layers of sample material, without damaging the underlying chemistry of organic samples such as polymers. As a result, GCIS has allowed chemical-damage-free analysis to reach micrometers below the sample surface. This depth of analysis can be highly time consuming, however, and total experimental times can range from multiple hours to days.&nbsp;</p><p>The addition of femtosecond-laser-ablation (fs-LA) technology is alleviating this, allowing for XPS spectra to be collected from a depth of tens of µm into a sample in a matter of minutes. This is because the laser ablation occurs on the femtosecond timescale (i.e., nearly instantaneously), effectively eliminating the material removal time of the depth profile. Additionally, unlike other material removal techniques such as atomic ion beam impact (where a collision cascade effect is induced to remove surface material) fs-LA is capable of removing material without chemical damage due to the ultrashort columbic explosion process used to eject the material. The resulting profile is therefore representative of the actual sample chemistry.</p><h4><strong>Paint layer analysis&nbsp;</strong></h4><p>In traditional ion-beam depth profiling, analytical depths are generally limited to several hundred nanometers, up to a micrometer. This means that it is extremely difficult to analyze the interfaces between multiple micrometer-thick layers in a sample without the use of additional techniques such as ultralow-angle microtome (ULAM) sectioning.¹ The introduction of fs-LA technology, however, allows micrometers of material to be removed rapidly, enabling the characterization of layered samples.&nbsp;</p><p>As an example, a multi-layer paint specimen (provided by the University of Surrey, UK) was depth profiled using the <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/products/2206"><strong>Thermo Scientific™ Hypulse™ Surface Analysis System</strong></a>. The sample consists of an aluminum substrate coated with a 5 µm layer of polyurethane primer followed by a 25 µm PMMA/PVdF topcoat.</p><p>The depth profile was generated using a 1,030 nm laser with an energy of 250 µJ for ablation, along with a 30 µm X-ray spot size for data collection. XPS spectra were collected after each ablation cycle to obtain an atomic concentration plot through both paint layers into the substrate material (Figure 2).&nbsp;</p><p>5 distinct regions throughout the analyzed depth can be seen. The top surface of the sample consists of an adventitious layer of carbon contamination, which is commonly found on samples exposed to air. The second layer is the 25 µm PVdF/PMMA topcoat, and the third layer is the PU primer. Between the primer and the final aluminum substrate layer, a clear increase in adventitious carbon is observed, similar to the signal seen at the top sample surface. This suggests residual carbon contamination was present on the substrate before the paint layers were applied.&nbsp;</p><p>It would take hours to produce the XPS depth profile shown in Figure 2 using traditional ion beam approaches. Even with the use of a monatomic beam with a high energy per atom, the length of the analysis could still be just as long, depending on the sample material, and would sacrifice the chemistry of any organic/polymeric materials. The combination of fs-LA depth profiling and snapshot XPS acquisition, meanwhile, can reduce the experimental time to less than 20 minutes without inducing any chemical damage to the sample surface.</p><h4><strong>Summary&nbsp;</strong></h4><p>One of the most critical aspects of successful polymer XPS depth profiling is the preservation of the sample chemistry during material removal. Additionally, experiment time can be a significant limiting factor, and thicker samples could lead to reduced time for repeat experiments. The femtosecond laser ablation capabilities of the Hypulse Surface Analysis System provide fast, efficient, and chemical-damage-free material removal from a sample surface, enabling analysis multiple micrometers into a sample. This means that hidden sample interfaces, that were largely inaccessible before, can now be analyzed easily and efficiently</p>

News from LabRulezICPMS Library - Week 19, 2026

Article

Product

Application

Video

Science and research

Software

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

Everything from the world of analytical chemistry in one place. We connect people in solving their problems. At Labrulez you will find all the necessary information easily, quickly and clearly. Stop searching and start finding.

LabRulez

For over 200 years we have been helping people and organizations develop the skills and knowledge they need to succeed.
We develop digital education, learning, assessment, and certification solutions to help universities, businesses, and individuals move between education and employment and achieve their ambitions.

Wiley

Agilent Sample rack for 16 mm od tubes, 60 positions, 6610025400 (New)

60-position Agilent sample rack for 16 mm OD tubes, compatible with SPS 3, SPS 4 and ASX 500 autosamplers, supporting reliable high-throughput elemental analysis.

Agilent sample rack 6610025400 for 60 tubes (16 mm), compatible with SPS 3, SPS 4, and ASX 500 autosamplers.

Marketplace products from category Accessories focused on Sample Preparation from LabRulez - page 1

Related content

Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections

News from LabRulezICPMS Library - Week 19, 2026

Wiley expands its trusted IR and Raman spectral library collections