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Preprints posted in the last 30 days, ranked by how well they match Molecules's content profile, based on 39 papers previously published here. The average preprint has a 0.05% match score for this journal, so anything above that is already an above-average fit.

1
Glycine molecule radical: Predicted properties and dipeptide formation

Synak, J.; Blazewicz, J.

2026-07-10 bioinformatics 10.64898/2026.07.07.736934 medRxiv
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Numerous advances in quantum and computational chemistry over the last decades, well as the development of computer science, allowed utilisation of more precise and complex models, which can be now applied to much bigger systems than in the past. The authors used Gaussian, coupled with theoretical methods, to predict a new way of peptide bond formation, which could have taken place in prebiotic conditions. To better tackle this difficult task, the properties of substrates (glycine-derived radicals) were extensively analysed, using the aforementioned tool - Gaussian, paired with taking resonance and hybridisation into account, to better understand the stereochemistry and the very nature of processes taking place. The result is a series of reactions, which without any sophisticated catalysts and with relatively low energy thresholds ({inverted exclamation}20 kcal/mol) can lead to formation of dipeptides (and further, oligopeptides). The authors also hope, the other predicted properties of the investigated molecules can be of use to any researcher, who would like to utilise them in their experiments. Author summaryOur goal was to investigate a way first peptide bonds in prebiotic conditions could have been formed. This is an extremely important step in research into the beginning of life on Earth. We found a very promising series of reactions, which uses atomic hydrogen as its only catalyst and confirmed our expectations with theoretical calculations, using Gaussian. There are two radicals derived from glycine, which perform major roles in the process, so we investigated their properties with Gaussian and verified that the results are in agreement with our own theoretical considerations. This involved checking for possible geometric isomers and conformers and creating models which could explain their properties. We are well aware that such calculations have limitations and there is no model, which is 100% accurate, so our results should be further confirmed by empirical data in the future. However, we still to be as thorough as possible in how we approached the subject.

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Reversal effects of Isochlorogenic acid A on HBV-induced transcriptional dysregulation and apoptotic signaling

Koyaweda, G.; Glitscher, M.; Miskey, C.; Hildt, E.

2026-06-23 microbiology 10.64898/2026.06.23.733975 medRxiv
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Chronic hepatitis B virus (HBV) infection contributes to hepatocellular carcinoma by disrupting host transcription, cell-cycle control, and apoptotic signaling. Isochlorogenic acid A (ICAA), a natural compound with antiviral and hepatoprotective properties, was previously shown to inhibit HBV replication by interfering with multiple steps of the viral life cycle. Because chronic HBV often reflects an imbalance between proliferation and cell death, we investigated how ICAA affects gene expression related to these processes in the presence or absence of HBV. We performed transcriptome analysis using RNA sequencing (RNA-seq) in HepAD38 cells (a HepG2-derived stable HBV-expressing line) and HepG2 control cells (HBV-negative) treated with ICAA or DMSO. HBV caused major differences in gene expression in HepAD38 cells compared with HBV-negative HepG2 cells. Principal component analysis showed that ICAA significantly altered HBV-dependent expression patterns, resulting in 189 differentially expressed genes (DEGs) that were regulated in opposite directions by both HBV and ICAA. Functional enrichment analysis highlighted pathways in viral carcinogenesis, apoptosis, MAPK signaling, and p53 signaling. Annexin V/propidium iodide assays showed apoptotic cells in both treated and untreated HepAD38 cultures, with only minor pattern changes. Mechanistically, in untreated HBV-positive cells caspase-9 cleavage failed to activate PARP, suggesting that induction of intrinsic apoptosis is followed by blocked execution. In contrast, ICAA inhibits caspase-9 cleavage in a dose-dependent manner, while activating PARP. Consistent with this, ICAA treatment increased apoptotic DNA fragmentation in HepAD38, reflecting the proapoptotic potential of ICAA under these conditions facilitating the elimination of HBV-positive cells by apoptosis. These findings highlight the potential therapeutic relevance of this compound in processes associated with HBV pathogenesis, together with its antiviral effect. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=185 SRC="FIGDIR/small/733975v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@38d107org.highwire.dtl.DTLVardef@235a13org.highwire.dtl.DTLVardef@ee988aorg.highwire.dtl.DTLVardef@60cb13_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Abbapolin inhibitors of the PLK1 PBD as Prostate Cancer Therapeutics, in vivo activity and synergy with androgen therapy

Merhej, G.; Ramamoorthy, G.; Chapagai, D.; Farahani, M. E.; Kong, Y.; Rao, C. N.; Stafford, J.; Mack, Z. T.; Socia, C.; Kumari, S.; Hogan, K.; Jani, N.; Pena, M. M.; Nurmemmedov, E.; Babic, I.; Chen, M.; Liu, X.; Wyatt, M. D.; McInnes, C.

2026-07-09 cancer biology 10.64898/2026.07.02.736204 medRxiv
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Polo-like kinase 1 (PLK1), a key regulatory protein controlling entry into and passage through mitosis, has been targeted through its kinase domain (KD) with mixed clinical success. Inhibition through the Polo-box domain (PBD) is a viable alternative through targeting the sub-cellular localization and kinase activity of PLK1. Novel non-peptidic compounds, termed abbapolins, were discovered through the REPLACE strategy and have been lead optimized through structure-based strategies and screening analogs in the NCI-60 tumor cell panel. Proteomic analysis revealed a correlation between abbapolin activity and PLK1 protein levels in the cell lines part of the NCI-60. Prostate cell lines were identified as among the most sensitive and led to further detailed studies of their activity in prostate cancer models. Compounds were evaluated for their pharmacokinetic properties, and in vivo efficacy, and results showed significant antitumor xenograft activity with no observable gross toxicity. Treated tumors were analyzed for loss of PLK1, which was previously shown to be induced by abbapolin binding. Results obtained showed a significant degradation of PLK1 in abbapolin-treated vs untreated tumors, thereby confirming on-target action in vivo and revealing PLK1 levels as a potential pharmacodynamic marker. Lead compounds were shown to sensitize PC tumors resistant to androgen deprivation therapy paving the way for future combination studies in vivo. These data provide an alternative pathway for effective PLK1 therapeutics that avoid the reported problems of molecules targeting the KD, in vivo proof-of-concept for the REPLACE strategy and validation for targeting the PBD as an anti-tumor drug development strategy.

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Selenium-enriched rapeseed extract synergizes with chemotherapy drug cisplatin in inhibiting proliferation and promoting apoptosis of colorectal cancer cells

Duan, X.; Lu, Y.; Zhou, H.; Zhang, Z.; Zhou, Z.; Wang, M.; Dun, X.; Chen, Z.; Zhu, Y.; Wang, H.; Jiang, L.

2026-07-10 cancer biology 10.64898/2026.07.06.736755 medRxiv
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Chemotherapy treatment of colorectal cancers (CRC) using cisplatin (CDDP) encounters problems of drug resistance by the cancer cells and cytotoxicity to normal cells, highlighting the urgent need for joint therapeutical strategies. Selenium-enriched rapeseed extracts exhibit anti-cancer effects but the bioactive components and mechanisms remain unclear. Here, we applied different solvents to fractionate the extracts from Selenium-enriched rapeseed and found that the water extract (WE) fraction significantly enhanced the cytotoxic effect of CDDP on cancer cells but no damage on normal cells. HPLC-ICP-MS analysis revealed that methylselenocysteine (MSC) and selenocystine (SeCys2) were the main selenium speciation in WE. Through cell biology and integrative multi-omics analysis, we found a synergistic anti-CRC cell effect when combining CDDP with MSC, sulforaphane (SFN), celastrol (Cel), Indole-3-carbinol (I3C), -linolenic acid (ALA) or linoleic acid (LA). We propose that the CDDP-WE combination treatment holds the promise for improving curative efficacy for chemo-refractory CRC patients in the future.

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Targeting Dengue Virus NS3 Helicase: Biochemical and Computational Evaluation of Catechins from Camellia sinensis as Potential Therapeutic Leads

Wojciechowski, M. K.; Goyzueta-Mamani, L. D.; Chavez-Fumagalli, M. A.; D'Antonio, E. L.

2026-06-23 biochemistry 10.64898/2026.06.22.733882 medRxiv
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Dengue Virus Serotype 2 is a human pathogenic flavivirus that encodes a non-structural protein 3 (DEN2-NS3) containing a helicase domain essential for viral replication. DEN2-NS3 utilizes energy derived from NTP hydrolysis to unwind dsRNA and dsDNA. A galloylated catechin, (-)-epigallocatechin gallate (EGCG), was previously reported to be highly potent against the Zika Virus NS3 helicase, with an IC50 value observed at 295.7 nM. This prompted an investigation to determine if three catechins, namely, (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and EGCG, would act as potent inhibitors of DEN2-NS3. Enzyme-inhibition assays revealed that the helicase catalytic domain, DEN2-NS3(S171-K618), is strongly inhibited by these galloylated catechins. We observed Ki values of 400 {+/-} 86.6 nM for EGCG (mixed-mode inhibition with respect to ATP) and 550 {+/-} 250 nM for ECG (uncompetitive inhibition with respect to ATP). Furthermore, using a computational workflow starting with SiteMap, we provide evidence that a highly druggable pocket exists within the RNA-binding cavity, involving residues ASP290, ARG387, ASP409, MET429, HIS487, ASP541, ARG599, and ASP603. These catechins were each analyzed through 200-ns molecular dynamics (MD) simulations to evaluate the binding stability within the target DEN2-NS3 binding pocket. Computational results revealed that EGCG and ECG maintained high stability, forming shared, highly persistent amino acid contacts (>45% occupancy) with ASP603, ARG599, ASP541, and ARG387. In conclusion, we have demonstrated that EGCG and ECG achieve strong binding and allosteric disruption of the critical RNA-binding channel. We suggest that future structural optimization of these compounds into stable prodrug derivatives could yield promising antiviral therapies. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=99 SRC="FIGDIR/small/733882v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@2db363org.highwire.dtl.DTLVardef@5c2fdaorg.highwire.dtl.DTLVardef@49bf8eorg.highwire.dtl.DTLVardef@1bf31f1_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Green-synthesized silver nanoparticles enhance Guibourtia tessmannii antithromboinflammatory therapeutic potential

Eya'ane Meva, F.; Gouli Lougui, L. P.; Nguemfo, E. L.; Fannang, S. v.; Ntoumba, A. A.; Bamal, H.-D.; Beglau, T. H. Y.; Tako Djimefo, A. K.; Mintang Fongang, U. A.; Sone Enone, B.; Tchangou Njiemou, A. F.; Evouna, D. I. M.; Yinyang, J.; Chimi Tchatchouang, G.; Fonye Nyuyfoni, G.; Janiak, C.

2026-07-06 pharmacology and toxicology 10.64898/2026.07.03.736249 medRxiv
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Introduction: Thromboinflammation, which represents the pathological interplay between inflammation and thrombosis, is a leading cause of global mortality. Current therapies are frequently associated with an increased risk of bleeding and do not adequately address the inflammatory component of the disease. The African tree Guibourtia tessmannii represents a promising source of natural anti-inflammatory compounds. This study aimed to synthesize and characterize silver nanoparticles using an aqueous bark extract of G. tessmannii (GT-AgNPs) and to evaluate their anti-inflammatory and anticoagulant properties. Methods: GT-AgNPs were synthesized by reducing silver nitrate with an aqueous extract of G. tessmannii bark. The nanoparticles were comprehensively characterized using UV-Vis spectroscopy, FTIR spectroscopy, powder X-ray diffraction, and scanning electron microscopy. In vitro anti-inflammatory activity was evaluated through inhibition of bovine serum albumin denaturation, whereas in vivo anti-inflammatory activity was assessed using the carrageenan-induced rat paw edema model. Anticoagulant activity was investigated by measuring activated partial thromboplastin time (aPTT) and prothrombin time (PT), corresponding to the intrinsic and extrinsic coagulation pathways, respectively. Results: The synthesis successfully produced GT-AgNPs with an average particle size of approximately 20 nm. Both the aqueous extract and GT-AgNPs exhibited marked anti-inflammatory activity. The nanoparticles achieved 95% inhibition of protein denaturation in vitro and 95% inhibition of carrageenan-induced paw edema in vivo at a dose of 0.4 mg/kg body weight after 5 h. Furthermore, both the extract and GT-AgNPs demonstrated dose-dependent anticoagulant activity. Conclusion: The study demonstrated that GT-AgNPs, synthesized from the bark of G. tessmannii, possess significant anti-inflammatory and anticoagulant properties. These findings highlight the potential of GT-AgNPs as nanotherapeutic candidates for the management of thrombo-inflammatory disorders.

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Characterization of ATM gene expression and evaluation of Reactive Oxygen Species in Silibinin-treated SKBR3 cells

Nademi, N. S.; Motamed, N.

2026-07-09 cancer biology 10.64898/2026.07.02.736131 medRxiv
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BackgroundReactive Oxygen Species (ROS) are the small, unstable and highly reactive species, having DNA oxidizing ability. Oxidation of the DNAs purine and pyrimidine bases can lead to single or double strands in this macromolecule. In this situation, the ATM molecule, a serine-threonine kinase, targets several proteins for phosphorylation, which causes the cell cycle to stop and the DNA damage repair begins. It has previously been proven that natural polyphenols have the cancer inhibiting properties due to their high efficacy and low side effects. Silibinin is the main herbal and medical ingredient in Milk Thistle (Silybum marianum) is a polyphenol flavonolignan, which has been widely considered as an antioxidant and anticancer agent. The purpose of the present study was to investigate the ATM gene expression and measurement of reactive oxygen species (ROS) in SKBR3 cell line, treated with Silibinin. Materials and MethodsAt first, the SKBR3 cell line was cultured in RPMI1640 culture medium and MTT assay was carried out to evaluate the Silibinin cytotoxicity. Flow Cytometry was carried out for cell cycle analysis, apoptotic induction, and ROS detection. While, Real Time PCR was used to evaluate the ATM gene expression in the Silibinin-treated and un-treated SKBR3 cells. ResultsPresent results have shown that 150 {micro}M Silibinin had the most significant cytotoxicity and apoptotic induction influence after the treatment period of 48 h. Flow cytometry data have shown that Silibinin induced considerable amount of apoptosis and caused cell cycle arrest at G1/S phase and induced production of ROS. Real-time PCR results have revealed that Silibinin increased the ATM expression in SKBR3 cell line. ConclusionSilibinin causes increased ATM gene expression by inducing ROS production, which initiates cell cycle arrest and apoptotic induction in SKBR3 cells line.

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Convergent anti-MRSA potency across compositionally distinct essential oils: a chemotype similarity index for strain-dependent chemistry-activity analysis

Bhat, A.; Sherry, A.

2026-07-03 microbiology 10.64898/2026.07.02.736015 medRxiv
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Antimicrobial resistance represents a continuing threat to clinical infection management, with methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Escherichia coli identified by the World Health Organization as priority pathogens. This study evaluated the antimicrobial activity, synergistic potential, and chemical composition of six plant-derived preparations (three ethanolic extracts: nettle, thyme, rosemary; and three essential oils: lavender, lemongrass, doTERRA Peace blend) against MRSA, methicillin-sensitive S. aureus (MSSA), and E. coli K-12 by disc diffusion, broth microdilution, post-exposure culturability, antimicrobial interactions assessed by checkerboard assay, and GC-MS profiling. Disc diffusion produced no interpretable zones of inhibition for any plant preparation tested; however, broth microdilution revealed reproducible inhibitory activity within published ranges across the panel. Three essential oils achieved a median Minimum Inhibitory Concentration (MIC) of 0.39 mg/mL against MRSA despite presenting compositionally distinct chemotypes: lavender was linalool-dominated (61% combined), lemongrass was citral-dominated (76%), and the doTERRA blend was sesquiterpene-rich. Rosemary ethanolic extract achieved the same potency (0.39 mg/mL) against MSSA. No preparation produced a bactericidal reduction (>=3 log10 CFU/mL) at any timepoint, with all reductions transient and recovering by 24 hours. Checkerboard combinations of plant preparations with vancomycin and ciprofloxacin were uniformly classified, according to the Fractional Inhibitory Concentration Index (FICI), as indifference/no interaction, attributable in part to inoculum-mediated effects on vancomycin MIC. To analyse the relationship between chemical composition and antimicrobial outcomes, we introduce a Chemotype Similarity Index (CSI), a chemometric framework quantifying pairwise compositional similarity between essential oils by Pearson correlation and relating it to log2-MIC differences across strains. CSI revealed a strain-dependent chemistry-activity relationship, convergent against MRSA, monotonic against MSSA, and absent against E. coli, indicating that compositional similarity predicts antimicrobial outcomes on a strain-specific basis. The convergence of three chemotypically divergent essential oils with the same anti-MRSA potency suggested a shared membrane-disrupting mechanism operating through distinct chemical routes. Although exploratory at this scale, the CSI framework provides a reusable analytical scaffold for linking phytochemical composition to antimicrobial activity, and identifies the MRSA convergence as a specific direction for mechanistic investigation into the development of plant-derived antimicrobial adjuncts.

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Large-scale production of melanin nanoparticles from Pseudomonas stutzeri strain BTCZ109

Mathew, D.; Bhat, S. G.

2026-07-10 microbiology 10.64898/2026.07.10.737634 medRxiv
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Past few decades witnessed a boom in pharmaceutical and bioproduct industry with the help of bioprocess technology. Industrially important bioproducts can be produced in large scale for commercialization with the help of fermenters. Here in, pharmaceutically valuable bioproduct melanin, synthesized from Pseudomonas stutzeri strain BTC109 by using two different sized bioreactors. Under controlled conditions the bacteria were allowed to synthesis melanin nanoparticles. The important parameters to be monitored here are pH, dissolved oxygen, agitation, aeration, melanin production and cell biomass concentration. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=163 SRC="FIGDIR/small/737634v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@d92fe5org.highwire.dtl.DTLVardef@d76c07org.highwire.dtl.DTLVardef@f5516forg.highwire.dtl.DTLVardef@1b5864b_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIPharmaceutical and bioproduct development industries witnessed a shoot up due to bioprocess technology. C_LIO_LIIndustrially important bioproduct like melanin can be produced in large scale with the help of industrial fermentation technology. C_LIO_LIThe product thus obtained was found to be nano sized and it can be commercialized. C_LI

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The Gompertz curve for estimating growth rates of Protein Data Bank and protein folds

Sato, K.; TOMII, K.

2026-06-26 bioinformatics 10.64898/2026.06.24.732253 medRxiv
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The Protein Data Bank (PDB) is an ever-growing, open-access repository of structural data of biological molecules. This international database has been instrumental in the development of artificial intelligence and deep learning models for protein structure prediction and design. The PDB growth is a crucially important factor influencing further development of these models. Therefore, after analyzing the growth trend in PDB depositions since the archive's launch, we found that it is well fitted by the Gompertz function, a growth curve used across various disciplines. Furthermore, we observed that the function captures the "discovery of novel folds", i.e., the cumulative number of distinct folds among protein domains that constitute most of the PDB. Consequently, based on the fitting results, we estimated the likely numbers of PDB entries and protein folds. These findings provide insights into deceleration of growth in recent years and enable us to assess anticipated trends.

11
Protein hydration and druggability

Panasenko, S.; Khorev, V.; Petukhov, M.

2026-07-08 biophysics 10.64898/2026.07.06.736750 medRxiv
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A priori assessment of target proteins' druggability remains an unsolved problem in the field of drug development. The empirical approaches widely used to solve this problem demonstrate low efficiency. In this work, we investigated the factor of hydration of a representative set of 65 evolutionarily and structurally unrelated human enzymes in a water environment. This factor depends only on the structure of the proteins, and not on the physical and chemical properties of any potential ligands. The results show that, unlike the widely used approaches based on calculations of the accessible surface area (ASA), the content of low-entropy water molecules (LEW) in the active sites of human enzymes is systematically higher than that in other areas of their surface, including inactive cavities. Optimal criteria and a step-by-step procedure for identifying protein ligand binding sites are proposed. The proposed approach, based on the calculation of the LEW content in the first hydration layer of potentially interesting target proteins, makes it possible to evaluate their medicinal suitability even before the development of any ligands. The article also presents the results of a comparative analysis of experimental Raman spectroscopy data and the results of molecular dynamics simulations of water hydrogen bonds using three widely used water models (TIP3P, OPC3, and TIP5P) and standard algorithms for calculating hydrogen bond networks.

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Low-molecular-weight Ulva lacinulata extract exhibiting anti-inflammatory and pro-autophagic activities in RAW 264.7 macrophages: a promising candidate for the development of active ingredients targeting low-grade inflammation

Cherfan, J.; Heerah, D.; Bodet, P.-E.; Musnier, B.; Saliba, J.; Sulpice, R.; Bodin, J.; Dufour, D.; Fioramonti, X.; Dinel, A.-L.; Joffre, C.; Delmarre, P.; Le Faouder, J.; Bouvret, E.; Arnaudin, I.; Maugard, T.; Bridiau, N.

2026-07-08 biochemistry 10.64898/2026.07.07.734444 medRxiv
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Marine macroalgae are valuable sources of bioactive compounds. In this study, we thus investigated the chemical composition and biological activity of an extract from the green seaweed Ulva lacinulata, composed of small bioactive compounds. Comprehensive compositional analyses and high-resolution mass spectrometry revealed its diverse molecular profile composed in particular of peptides/amino acid derivatives, saccharides, low-chain fatty diacids, oxylipins and minerals. Its anti-inflammatory activity was assessed after 6 h pre-treatment in LPS-stimulated cultured RAW 264.7 macrophages, showing that it significantly and dose-dependently reduced the expression and/or secretion of pro-inflammatory cytokines such as TNF-alpha; and IL-6, and targeted the NF-kB signaling cascade. It modulated the SIRT1-AMPK signaling axis and increased the LC3-II/LC3-I ratio, supporting the activation of a controlled autophagic response. This work highlighted the potential of this marine-derived extract as a safe and effective functional ingredient for the development of functional food and/or dietary supplements targeting chronic low-grade inflammation.

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A control-validated pan-proteome deep-learning pipeline nominates GPR35 as a candidate target of the orphan bacterial metabolite ligiamycin A

Martin, J.

2026-07-06 bioinformatics 10.64898/2026.07.01.735807 medRxiv
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Most microbial natural products with documented bioactivity lack an identified molecular target, which limits their development. We present an open, control-validated computational pipeline for natural-product target hypothesis generation. It combines a pan-proteome deep-learning drug-target interaction (DTI) model (a graph neural-network ligand encoder, an ESM-2 protein language-model encoder, and bidirectional cross-attention) with bias-corrected ranking and control-anchored molecular docking. Applying it to ligiamycin A, a 2022-described Streptomyces/Achromobacter co-culture decalin-amino-maleimide with no reported target, we find that the predicted interactions of the compound are dominated by class-A G-protein-coupled receptors. Using a drug with a known target (losartan) we identify and correct a frequent-hitter bias in the raw model; after correction the standout candidates are uniformly class-A GPCRs, led by the orphan receptor GPR35. Structure-based docking with matched positive and negative controls across three candidates corroborates GPR35 specifically: ligiamycin A scores comparably to the known GPR35 agonist zaprinast at the agonist pocket (-8.1 vs -8.3 kcal/mol; non-binder floor -5.5), whereas FFAR1 is excluded and histamine H2 is inconclusive. We propose GPR35 as a prioritized, experimentally testable target and release the workflow as a reusable tool. The result is a computational hypothesis that requires experimental validation.

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Galangin and Caffeic acid inhibit Methylglyoxal-induced Advanced Glycation End Product formation in Bovine Serum Albumin

Kanojia, N.; tiku, A.

2026-07-15 biophysics 10.64898/2026.07.09.737425 medRxiv
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Glycation, a non-enzymatic reaction occurring between sugars and biological macromolecules, plays a critical role in ageing and disease pathogenesis. Methylglyoxal (MG) is a highly reactive -oxoaldehyde that leads to the formation of endogenous advanced glycation end products (AGEs). These AGEs are associated with diabetes and many other diseases, including neurodegeneration and cancer. This is often through interactions with the receptor for advanced glycation end products (RAGE). Inhibition of glycation/AGEs formation using natural products to target cancer is an area of recent interest. In vitro AGEs formation was observed by browning of samples, increased fluorescence, and carbonyl stress. MG induced changes in the structure of BSA were analysed using electrophoresis, spectroscopy, TEM, AFM, DLS, and CD spectroscopy. Our results show that AGEs form random structures, oligomeric aggregates, and {beta}-sheets. Thioflavin T and Congo red staining further validated these findings. Galangin and Caffeic acid demonstrated significant antiglycation activity, suppressing AGEs formation in vitro. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/737425v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@113b391org.highwire.dtl.DTLVardef@7208a1org.highwire.dtl.DTLVardef@94c2e1org.highwire.dtl.DTLVardef@867b85_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIMethylglyoxal-induced Advanced Glycation End Products were prepared in vitro C_LIO_LIMethylglyoxal -induced structural modifications in BSA C_LIO_LIAGEs were characterised using various parameters C_LIO_LIBoth fluorescent and non-fluorescent AGEs were formed. C_LIO_LIPhytochemical treatment induced inhibition of AGEs formation C_LI

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Antiglycation effects of imidazole dipeptides and 2-oxo-imidazole dipeptides on glyceraldehyde-induced intracellular protein glycation and neuronal cell death

Yamada, Y.; Hashida, K.; Hayashi, K.; Yoshimochi, K.; Hirose, T.; Shimotsuma, M.; Hamada, Y.; Usui, K.; Yokoyama, N.; Hara, T.; Nishino, S.; Kakeya, H.; Tomonaga, S.; Ozaki, M.

2026-06-26 biochemistry 10.64898/2026.06.25.734660 medRxiv
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Glyceraldehyde (GA) contributes to the development of various diseases, such as diabetes and Alzheimer's disease via protein glycation and the formation of advanced glycation end products (AGEs); however, effective strategies for neutralizing GA are limited. Carnosine (Car), an imidazole dipeptide (IDP) that is abundant in meat, suppresses protein glycation by scavenging reactive aldehydes. There are only a few reports on the antiglycation activity of Car against GA. For other IDPs, such as anserine, balenine (Bal), and homocarnosine, there are almost no reports on their antiglycation activity. In this study, we demonstrated the antiglycation activity of four types of IDPs and 2-oxocarnosine (2-oxo-Car), an oxidized form of Car, against GA-induced intracellular protein glycation and neuronal cytotoxicity. Car and Bal exhibited significantly higher reactivity with GA compared with other IDPs and 2-oxo-Car. An in silico analysis suggested that the difference in reactivity is dependent upon intramolecular hydrogen bond formation and the conformation of each IDP. Although there were differences in reactivity with GA, LC-MS analysis revealed that all of the IDPs and 2-oxo-Car reacted with two molecules of GA to form adducts containing pyridinium rings. Car and Bal exhibited high reactivity with GA and markedly suppressed GA-induced cytotoxicity in SH-SY5Y cells. Western blot and qPCR analyses revealed that IDPs suppressed GA-induced protein glycation and the upregulation of endoplasmic reticulum and oxidative stress response genes. Our results indicate that IDPs represent a novel preventive approach to AGE-related diseases and provide a foundation for the development of strategies to treat GA-related neurotoxicity.

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Computational Design of Two Novel BRAF V600E Inhibitors: Exploiting Sulfoximine Bioisosterism and Chiral Constraints to Evade Paradoxical Activation

Yu, Z. H.; Siegel, J. B.; Morrow, E. R.

2026-06-30 pharmacology and toxicology 10.64898/2026.06.25.734343 medRxiv
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Metastatic melanoma is an aggressive cutaneous malignancy frequently driven by the oncogenic V600E mutation within the BRAF kinase. While first-generation Type IS BRAF inhibitors, such as dabrafenib, are currently prescribed to target this specific molecular vulnerability, paradoxical MAPK pathway activation, and acquired drug resistance necessitate the continuous development of structurally optimized lead molecules. In this study, chemical intuition, bioisosteric replacement, and computational molecular docking were employed to propose two novel BRAFV600E drug candidates. The proposed therapeutics, engineered to incorporate constrained sp3-hybridized aliphatic rings and a sulfoximine bioisostere, demonstrated thermodynamically superior docking scores within the mutant catalytic cleft compared to dabrafenib. Lastly, a homology analysis determined that Mus musculus is a suitable model organism for future preclinical studies and confirmed crucial structural selectivity against microbial off-target kinases.

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Ocimum gratissimum essential oil nanoemulsions as a safe topical nanoplatform for antibacterial and wound-healing activities

Fomesseng Negoue, A.; Eya'ane Meva, F.; Fokou, J. B. H.; Voundi Olugu, S. H.; Boudjeka, V.; Ngo Nyobe, J. C.; Belle Ebanda Kedi, P.; Houatchaing Kouemegne, A. M.; Etame Loe, G.

2026-07-07 pharmacology and toxicology 10.64898/2026.07.01.735794 medRxiv
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Background: Natural essential oils exhibit antimicrobial and wound-healing properties, but their therapeutic application is limited by poor water solubility, volatility, and instability. This study developed and characterized a nanoemulsion of Ocimum gratissimum essential oil (OGNe) and evaluated its physicochemical properties, dermal safety, antibacterial activity, and wound-healing potential. Methods: Essential oil was obtained by hydrodistillation and formulated into nanoemulsions by high-speed stirring emulsification. Physicochemical properties, including pH, droplet size, polydispersity index, and storage stability, were determined. Acute dermal toxicity was assessed in Wistar rats following OECD Test Guideline 402. Antibacterial activity was evaluated using broth microdilution, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill assays. Wound-healing efficacy was investigated using an excision wound model over 21 days using distilled water and trolamine serving as controls. Results: OGNe exhibited a stable milky appearance, near-neutral pH, and droplet sizes ranging from 26 to 224 nm. No signs of dermal toxicity or behavioral abnormalities were observed after topical administration. The nanoemulsion showed selective antibacterial activity, with the highest susceptibility against Acinetobacter baumannii (MIC = 1.125 L/mL), whereas Escherichia coli remained resistant. Time-kill assays demonstrated concentration-dependent bacteriostatic activity. In vivo, OGNe significantly accelerated wound contraction from day 3 onward (p < 0.0001), achieving healing rates comparable to or exceeding those of trolamine during the inflammatory and proliferative phases. Conclusion: Ocimum gratissimum nanoemulsions represent stable, biocompatible topical formulations that combine selective antibacterial activity with enhanced wound healing, supporting their potential as phytopharmaceutical nanoformulations for the management of acute skin wounds.

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Response surface methodology for melanin nanoparticle production optimization from producer strain Pseudomonas stutzeri BTCZ305 with invitro anti-inflammatory and wound healing potential

Mathew, D.; Bhatt, S. G.

2026-07-08 microbiology 10.64898/2026.07.08.737209 medRxiv
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Culture conditions were optimized for the production of melanin nanoparticle by the bacterial strain Pseudomonas stutzeri BTCZ 305. Response surface methodology was employed for determining the most significant fermentation conditions using variables including, pH, temperature and L-tyrosine concentration identified through one-factor-at-a time approach. Box-behnken design consisting of 17 different combinations of all these factors were performed. Using this methodology, a quadratic regression model was built and the optimal combinations of media constituents for maximum melanin production 1192.27 microg/mL were determined as temperature (32.5 degreeC), pH (8.5) and L-tyrosine concentration (7 g/L). Melanin production was obtained experimentally coincident with the predicted value and the model was proven to be adequate. The nanostructural distribution, its stability in colloidal suspension and particle size were also characterized with the help of TEM, particle size analysis and Zeta potential. The potent applicability of this molecule in anti-inflammation and wound healing was also elucidated.

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Toward pharmacologic therapy for glioblastoma: Characterization of the very long-chain acyl-CoA synthetase 3 (ACSVL3) inhibitor Grassofermata

Clay, E. M.; Shi, X.; Kolar, E. A.; Liu, Y.; Lal, B.; Watkins, P. A.

2026-07-08 cancer biology 10.64898/2026.07.07.736493 medRxiv
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Malignant brain tumors are among the most aggressive and difficult to treat human cancers. Glioblastomas (World Health Organization grade IV gliomas) are particularly lethal and refractory to treatment. Few drugs exist that are even somewhat effective. Our investigation of the physiologic role of fatty acid (FA) activating enzymes (acyl-CoA synthetase; ACS) identified an ACS that was widely expressed in gliomas but not in normal glial cells. Depletion of this enzyme, ACSVL3 (very long-chain ACS3), by knockdown or knockout decreased the malignant behavior of several glioma cell models including U87MG and Mayo-22 cells both in culture and when grown as xenografts. Hypothesizing that ACSVL3 is a potential therapeutic target in glioma, we conducted a search for inhibitors of this enzyme and found that CB5 (grassofermata) was a promising candidate. Treating U87MG glioma cells with CB5 slowed growth in monolayer culture; the growth rate was similar to that seen in cells in which ACSVL3 was either knocked down or knocked out. CB5 inhibited growth in a dose-dependent manner over a narrow range, and concentrations above 10 M were toxic. Treatment at the lower dose of 3 M inhibited growth of U87MG cells but was reversible, suggesting that this dose was not toxic. CB5- treated U87MG cells exhibited an altered morphology with a larger size and longer projections. In contrast, normal human fibroblasts treated with 10 M CB5, a concentration that was toxic to U87MG cells, showed no effect on either growth rate or morphology. Treating U87MG cells with 3 M CB5 induced differentiation as shown by increased expression of the astrocyte-specific marker glial fibrillary acidic protein (GFAP). In contrast, GFAP levels remained low in ACSVL3 knockdown cells. CB5- treated U87MG cells were less invasive, and thus less malignant, than either untreated cells or ACSVL3 knockout cells when assessed by a scratch wound healing assay. Acute treatment of U87MG cells with 3 M CB5 decreased the ability of these cells to degrade FA of differing chain lengths from 16-24 carbons by {beta}-oxidation, suggesting that decreased ACS enzyme activity contributes at least in part to the drugs mechanism of action. NOD/SCID mice receiving up to 32 mg/kg/day CB5 by intraperitoneal injection showed no obvious side effects, suggesting that the drug was well-tolerated. Xenografts induced by subcutaneous injection of U87MG cells in the flanks of NOD/SCID mice were allowed to grow for 8 days after which half of the mice were treated with 2 mg/kg/day CB5. After 7 days of treatment, xenograft growth slowed in the treated mice and by 12 days tumor size had begun to decrease, suggesting therapeutic efficacy. When a similar study was done using xenografts induced by subcutaneous injection of Mayo-22 cells, which are maintained as subcutaneous tumors in mice rather than in cell culture, the effect of CB5 on tumor growth or weight at sacrifice was not statistically significant. The results of these studies suggest that CB5 may have therapeutic value in malignant glioma. Additional studies using other glioma models and other drugs chemically related to CB5 seem warranted.

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There is no convincing evidence that Methylobacterium extorquens AM1 can produce N-deoxyschizokinen A

Gutenthaler-Tietze, S. M.; Weis, P.; Daumann, L. J.

2026-07-06 microbiology 10.64898/2026.07.03.736418 medRxiv
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It was recently reported that Methylobacterium extorquens AM1 produces the citrate-hydroxamate siderophore N-deoxyschizokinen A, identified by LC-HRMS. Multiple properties were inconsistent with the assignment: the feature eluted far later than the other schizokinen derivatives (17 min versus 6-8 min), a reversed-phase shift larger than a single-hydroxyl difference in a molecule can explain, further its accurate mass deviated from the calculated one by 28 ppm, well outside the error on the co-analyzed standards and its diagnostic m/z 105 and 77 fragments suggest a molecule with an aromatic moiety. A replicate comparison of identical samples in plastic versus glass autosampler vials was decisive: the m/z 387 feature was reproducibly present with plastic vials and absent with glass. We therefore conclude that the reported detection of N-deoxyschizokinen A in M. extorquens AM1 is an artifact, and recommend glass-vial and solvent-blank controls, an explicit accurate-mass threshold, and narrow MS/MS isolation when assigning trace siderophore-like features from complex extracts.