Journal of Natural Products

Actinoplanes teichomyceticus is a well-established producer of bioactive secondary metabolites, including the glycopeptide antibiotic teicoplanin. Although its antibiotic biosynthetic capacity has been extensively investigated, its siderophore diversity and any additional biological functions of these iron-chelating metabolites remain comparatively underexplored. We identified a reproducibly bioactive, teicoplanin-independent fraction that inhibited Bacillus spizizenii. Molecular networking applied to this fraction identified hydroxamate ferrioxamine and desferrioxamine-type siderophores as the dominant metabolites, including acylated analogs detected as Al3+- and Fe3+-chelated species. Robust siderophore secretion was confirmed by the CAS assay. Notably, siderophore-enriched fractions exhibited selective antibacterial activity against Gram-positive bacteria, with minimum inhibitory concentrations of approximately 16 {micro}g/mL against B. spizizenii and partial inhibition of Staphylococcus aureus, while no activity was observed against Escherichia coli. Synthetic C7 and C9 acyl-desferrioxamine analogs showed enhanced antibacterial activity upon Al3 chelation, indicating a metal-dependent bioactivity. These findings reveal an unexpected antibacterial role for ferrioxamine-type siderophores produced by A. teichomyceticus, extending their function beyond iron acquisition, possibly through a "Trojan horse" (or "Trojan metal") mechanism.

Cationic polymers, which mimic the structure of antimicrobial peptides (AMPs), are increasingly recognized as promising antimicrobial materials. Here, we report the synthesis and evaluation of a new class of cationic lipid-terminated oligomers (CLOs), comprised of 2C18-hydrophobic lipid tails, and short oligomeric cationic chains synthesised via Cu(0)-mediated reversible-deactivation radical polymerization (RDRP). Two 2-vinyl-4,4-dimethyl-5-oxazolone (VDM) oligomers with degrees of polymerization (DP) of 20 or 50 were synthesized using the lipid functional initiator (R)-3-((2-bromo-2-methylpropanoyl) oxy)propane-1,2-diyl dioctadecanoate (2C18-Br). Post-polymerization modification of the pendant oxazolone moieties was carried out using reactive amines, including N-Boc-ethylenediamine (BEDA) and N,N-dimethylethylenediamine (DMEN). Subsequent deprotection of the BEDA groups and quaternization of DMEN groups enabled the synthesis of six functional CLOs exhibiting distinct cationic functionalities. Antimicrobial assays against a panel of WHO bacterial and fungal priority pathogens (methicillin-resistant Staphylococcus aureus [MRSA], Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Candida albicans, and Cryptococcus neoformans) revealed that these CLOs exhibited potent and selective structure-dependent antibacterial activity, particularly against MRSA, with minimum inhibitory concentrations (MICs) in the clinically relevant range, below 4 {micro}g mL-1, comparable to antibiotics vancomycin and colistin. Among these, BEDA-functionalized CLOs demonstrated the strongest antimicrobial profile, which was significantly increased by increasing DP, as evidenced by a reduction in MIC values from 64 {micro}g mL-1 (for DP20) to [≤] 4 {micro}g mL-1 (for DP50) against A. baumannii. Biocompatibility assays against red blood cells and HEK293 cells indicated negligible toxicity, with haemolytic (HC50) and cytotoxic (CC50) values exceeding 512 {micro}g mL-1 across all CLOs. All CLOs displayed minimal activity against C. albicans (MIC [≥] 512 {micro}g mL-1). In contrast, activity against C. neoformans was influenced by both cationic functionality and DP, with DMEN-based CLOs exhibited superior antifungal activity at higher DP relative to their BEDA-based counterparts. Most CLOs displayed high selectivity (SI) toward MRSA (SI >128), while 2C18-O(BEDA)50 exhibited the broadest spectrum, showing potent antimicrobial activity and high selectivity against E. coli (MIC [≤] 4 {micro}g mL-1, SI [≥] 128), A. baumannii (MIC [≤] 4 {micro}g mL-1, SI [≥] 128), and MRSA (MIC [≤] 4 {micro}g mL-1, SI [≥] 128), along with moderate activity against P. aeruginosa (MIC = 32 {micro}g mL-1, SI > 16). Taken together, these findings elucidate the combined influence of end-group lipidation, cationic functionality, and polymer length in modulating antimicrobial activity, thereby establishing 2C18-terminated CLOs as a rationally tunable and biocompatible platform for antimicrobial material development.

Microorganisms in the human gut influence the efficacy and metabolism of host-targeted small molecule therapeutics, including the frontline Parkinsons disease drug levodopa (L-dopa). Previous work has identified a mechanism-based inhibitor of gut bacterial decarboxylases that degrade L-dopa, -fluoromethyltyrosine (AFMT). However, early experiments with AFMT in rodent models suggested undesirable in vivo metabolism by host tyrosine hydroxylase, producing a metabolite likely to worsen Parkinsons phenotypes and prevent application as an L-dopa co-treatment. Here, we demonstrate oxidation of AFMT in vitro by recombinant human tyrosine hydroxylase. We then develop AFMT analogs that retain activity against bacterial decarboxylases but have reduced susceptibility to host hydroxylation. Suitable arenes for inhibitor design were identified using assays with commercially available noncanonical amino acids, which revealed aryl difluorination as a promising modification. Difluoroaryl AFMT derivatives are less prone to degradation by tyrosine hydroxylase in vitro yet still inhibit L-dopa metabolism by bacterial decarboxylases. This work exemplifies how substrate reactivity can streamline design of mechanism-based enzyme inhibitors, as well as how constraints posed by the host can be incorporated during development of microbiome-targeted therapeutics. The compounds reported here are promising starting points for future studies in animal models and further exploration of gut bacterial effects on L-dopa treatment efficacy.

Pseudomonas aeruginosa is an adaptable organism, frequently found in chronic infections, and for which antimicrobial resistance is a growing concern. Therefore, there is an urgent need for alternative therapeutic strategies. Cationic antimicrobial peptides (AMPs) offer potent bactericidal activity but suffer from limited selectivity and potential host toxicity. To enhance species-specific targeting, we designed two prodrug variants of the AMP D-Bac8CLeu2,5 - EEEE-D-Bac8CLeu2,5 and ELEG-D-Bac8CLeu2,5 -- engineered for activation by the P. aeruginosa extracellular aminopeptidase PaAP. While both prodrug motifs effectively neutralized the positive charge of D-Bac8CLeu2,5 and prevented DNA-peptide complex formation, EEEE-D-Bac8CLeu2,5 showed negligible antimicrobial activity due to slow and incomplete activation. In contrast, ELEG-D-Bac8CLeu2,5 underwent rapid PaAP-mediated activation, restoring bactericidal activity in planktonic cultures and biofilms. PaAP contributed significantly to complete prodrug activation, particularly within biofilms, where the accumulation of partially activated intermediates correlated with biphasic killing kinetics. The prodrug showed reduced activity against other ESKAPEE pathogens, demonstrating selective activation by P. aeruginosa. Experiments selecting resistant bacteria revealed distinct mutations in lipopolysaccharide biosynthesis pathways for D-Bac8CLeu2,5 and the prodrug, with limited cross-resistance. These findings establish aminopeptidase-activated AMP prodrugs as a promising approach for species-selective antimicrobial therapy and highlight the feasibility of exploiting bacterial enzymes for controlled antimicrobial peptide activation. Table of contents graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=99 SRC="FIGDIR/small/715093v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@4a5505org.highwire.dtl.DTLVardef@13e578org.highwire.dtl.DTLVardef@3e3080org.highwire.dtl.DTLVardef@e24266_HPS_FORMAT_FIGEXP M_FIG C_FIG

The genetically authenticated Finnish hop genotype LUKE 2541 obtained from wild was evaluated for antibacterial, anti-inflammatory, and anticancer activities. Water extracts from hop cones inhibited the Gram-positive bacteria Staphylococcus aureus and Bacillus cereus, with MIC values of 0.094- 0.188mg/mL, whereas Gram-negative strains showed limited sensitivity. In LPS-primed THP-1 cells, both IPA and IPA-Control extracts reduced reactive oxygen species formation in a dose-dependent manner, exhibiting similar IC50 values (50.41{micro}g/mL and 35.41{micro}g/mL). This hop genotype also displayed clear tissue- and solvent-dependent antiproliferative effects in human cancer cell lines. Bioactivity was strongly enriched in hop cones and predominantly associated with non-polar extracts, particularly hexane and dichloromethane fractions, which produced marked, dose-dependent reductions in cell viability. In contrast, aqueous and methanolic extracts were largely inactive, underscoring the critical importance of extraction chemistry and tissue selection. Sensitivity varied among cancer cell lines, with colorectal cells generally more responsive and leukemia cells less affected, highlighting cell-specific susceptibility. Further research is needed to elucidate underlying mechanisms, determine selectivity toward non-malignant cells, and identify the active compounds responsible for all in all investigated effects.

A cassane diterpene, 6{beta}-cinnamoyl-7-hydroxyvouacapen-5-ol (6{beta}CHV), isolated from Caesalpinia pulcherrima, has emerged as a promising anticancer drug lead with reported Wnt/{beta}-catenin pathway inhibitory activity and in vivo safety. The present study reports the in vivo pharmacokinetics and tissue distribution of 6{beta}CHV in Wistar rats following a single oral dose of 200 mg/kg. A reproducible RP-HPLC-UV method was developed and validated for quantifying 6{beta}CHV in rat plasma and tissues. Chromatographic separation was achieved using a gradient elution of methanol and water. The method was subsequently applied to investigate the pharmacokinetics and tissue distribution of 6{beta}CHV. Plasma pharmacokinetic analysis revealed delayed and moderate absorption, with a Tmax of 4 h and a Cmax of 1314.12 ng/mL. Following absorption, 6{beta}CHV is distributed widely across peripheral tissues, including the liver, heart, lungs, spleen, and kidneys, as well as pharmacological sanctuary sites such as the brain and testes. The highest concentrations were observed in the stomach, small intestine, and liver, with detectable levels persisting up to 24 h, reflecting extensive tissue partitioning and retention. Overall, these findings demonstrate that oral administration of 6{beta}CHV is feasible. However, the delayed absorption suggests that further optimization of formulation or alternative administration routes may enhance systemic exposure. This study provides the first comprehensive pharmacokinetic and tissue distribution profile of 6{beta}CHV, supporting its continued preclinical development as a potential anticancer therapeutic. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=125 SRC="FIGDIR/small/715187v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@4ae86forg.highwire.dtl.DTLVardef@1e1e51aorg.highwire.dtl.DTLVardef@1881c43org.highwire.dtl.DTLVardef@f7789f_HPS_FORMAT_FIGEXP M_FIG C_FIG

Formate is emerging as an important molecule in carbon capture and utilization technologies. However, its low electron density makes formate less attractive for energy storage. Some hydrogenotrophic methanogens can reduce formate to methane, thereby upgrading it into an established energy carrier. The bottleneck in this process is that 75% of the carbon is lost as carbon dioxide, and achieving a complete formate-to-methane conversion requires co-feeding hydrogen. However, hydrogen-dependent genetic regulation of formate metabolism inhibits simultaneous formate and hydrogen utilization in hydrogenotrophic methanogens. Here, we compared the catalytic performance of the genetically modified strain Methanothermobacter thermautotrophicus {Delta}H (pFdh) with M. thermautotrophicus Z-245 by conducting continuous cultivation at different hydrogen concentrations. While M. thermautotrophicus Z-245 is a natural formatotroph, M. thermautotrophicus {Delta}H (pFdh) was engineered to enable formate utilization via episomal expression of a formate dehydrogenase-gene cassette. We found that M. thermautotrophicus {Delta}H (pFdh) can simultaneously utilize formate and hydrogen. It continuously consumed formate at {approx} 0.1 mM dissolved hydrogen, enabling a 75.6% formate-to-methane conversion efficiency. M. thermautotrophicus Z-245 showed a declining formate consumption at {approx} 0.016 mM and only reached a maximum stable efficiency of 36.3%. These results suggest that M. thermautotrophicus {Delta}H (pFdh) is largely insensitive to hydrogen-induced genetic regulation; however, it still faces redox-related metabolic limitations at dissolved hydrogen concentrations above 0.4 mM. Overall, the findings reveal a potential strategy to circumvent hydrogen-induced regulation of formate metabolism and identify M. thermautotrophicus {Delta}H (pFdh) as a promising biocatalyst for formate-to-methane conversion.

Current mechanical and chemical recycling strategies address less than 10% of global plastic waste, necessitating alternative valorization routes. Biological upcycling via enzymatic depolymerization combined with microbial conversion of the resulting monomers offers a promising pathway to transform mixed plastic waste into valuable alternatives. Here, we employed a single engineered Pseudomonas putida KT2440 for simultaneous co-utilization of five plastic monomers including ethylene glycol, terephthalic acid, adipic acid, 1,4-butanediol, and L-lactic acid, which can be derived from enzymatic hydrolysis of polyethylene terephthalate (PET), polybutylene adipate-co-terephthalate (PBAT), polyester-polyurethanes (PUs), and polylactic acid (PLA). Continuous fermentation over 21 days with alternating mixed-monomer feeds achieved steady state growth and complete substrate depletion, yielding adaptive mutations that informed iterative strain improvement. Further engineering enabled the biosynthesis of (R)-3-hydroxybutyrate (R-3HB), and 0.70 g L-1 R-3HB was produced directly from enzymatic hydrolysates of blended PET, PBAT, and TPU. These results establish a viable bio-based approach for upcycling realistic mixed plastics into value-added bioproducts.

Natural products, especially polyphenol-rich medicinal plants, are increasingly investigated as multitarget therapeutics in both human and veterinary medicine for angiogenic regenerative properties and for inflammation based-diseases. Recent developments in natural product formulation, notably microencapsulation, have been shown to improve the stability, bioavailability, and controlled release of bioactive compounds. The integration of complementary in vitro and in vivo models is critical for evaluating both efficacy and translational potential. In this context, the present study assessed the phytochemical composition and biological activity of a microencapsulated Ecuadorian Vaccinium floribundum extract (VFM), using a combination of in vitro and in vivo approaches. VFM biochemical characterization identified 15 compounds, including flavonoids, procyanidins, dihydrochalcones, and phenolic acids, with chlorogenic acid and quercetin as the most abundant metabolites. Anthocyanins ideain and petunidin were also detected, confirming a rich bioactive profile. Primary porcine thoracic aortic endothelial cells (pAECs) were treated with VFM to assess cell viability and angiogenic potential and challenged with bacterial lipopolysaccharide (LPS) in the presence or absence of the extract. Anti-inflammatory effects were further evaluated in vivo using a carrageenan-induced mouse paw edema model. VFM enhanced endothelial cell viability, promoted capillary-like network and modulated early angiogenic signaling pathways. It mitigated LPS-induced endothelial dysfunction by reducing pro-inflammatory cytokines and oxidative stress markers. In vivo, paw edema assays confirmed its anti-inflammatory efficacy, with microencapsulation likely sustaining bioactive release. These findings support the traditional use of Vaccinium floribundum and highlight its potential for developing nutraceutical formulations targeting vascular and inflammatory disorders.

Inflammation serves as a vital physiological process essential for preserving health and countering illness. Yet, persistent inflammation drives osteoclastogenesis and ongoing bone erosion in rheumatoid arthritis (RA), mainly via macrophage activation and overproduction of pro-inflammatory cytokines like TNF-, IL-1{beta}, and IL-6. Limitations of prolonged conventional treatments underscore the need for safer small-molecule inhibitors that address both inflammation and osteoclast formation. Chalcones, natural plant defense compounds, exhibit diverse pharmacological properties including anti-inflammatory, anticancer, antibacterial, antifungal, and antiparasitic actions, owing to their characteristic reactive , {beta}- unsaturated carbonyl moiety. This study assessed chalcone derivative 7a for its anti-inflammatory effects in vitro and in vivo, alongside its capacity to modulate osteoclast differentiation, offering the inaugural demonstration of its dual anti-inflammatory and anti-osteoclastogenic properties. In LPS-stimulated macrophages, 7a substantially curtailed nitric oxide production, curbed pro-inflammatory cytokines (TNF-, IL-1{beta}, IL-6), and concentration-dependently diminished iNOS and COX-2 expression while inhibiting reactive oxygen species levels. In vivo, oral 7a dosing potently alleviated carrageenan-evoked paw swelling and restored serum lactate dehydrogenase and C-reactive protein to normalcy. In LPS-exposed mice, it further lowered systemic cytokines and rectified dysregulated biomarkers such as LDH, ALP, ALT, AST, creatinine, and urea. Moreover, in RANKL-stimulated osteoclast cultures, 7a markedly suppressed osteoclastogenesis by downregulating pivotal markers like tartrate-resistant acid phosphatase (TRAP) and matrix metalloproteinase-9 (MMP-9). Derivative 7a also enhances antioxidant defense--superoxide dismutase and catalase--via blockade of NF-{kappa}B and MAPK pathways. Overall, chalcone derivative 7a displays robust anti-inflammatory and anti-osteoclastogenic activity, positioning it as a compelling candidate for RA therapy.

Globally, about 264 million individuals across all age groups are impacted by depression, a prevalent central nervous system (CNS) condition. Chronic and enduring depression might result in significant health consequences. Numerous pharmaceutical antidepressants exist for the management of mild to severe depression, largely functioning by modifying neurotransmitter levels in the brain. Nevertheless, these drugs frequently induce a variety of side effects, such as insomnia, constipation, exhaustion, drowsiness, and anxiety. Saffron (Crocus sativus L.) is widely acknowledged as a natural antidepressant with little adverse effects. This study investigated the potential antidepressant mechanisms of saffrons principal bioactive compounds safranal, crocin, and picrocrocin via molecular docking against critical target proteins associated with depression, namely the dopamine transporter (DAT), serotonin transporter (SERT), and monoamine oxidase B (MAO-B). Molecular docking was conducted with AutoDock 4.2 to assess the binding affinity and interaction energy of these drugs with the target proteins. Furthermore, Discovery Studio facilitated the viewing and study of both interacting and non-interacting residues at the docking sites, juxtaposing these interactions with those of established inhibitors in crystal structures. The permeability of the blood-brain barrier (BBB), pharmacokinetic characteristics, and toxicity profiles of saffron components were evaluated using SWISS ADME, DataWarrior, and Osiris Molecular Property Explorer. Among the evaluated elements, safranal had the greatest potential as a competitive inhibitor of the dopamine transporter, according to its notable blood-brain barrier permeability, robust binding affinity, and analogous interaction residues in comparison to nortriptyline, a recognized inhibitor. Our findings indicate that safranal may be a viable natural alternative to traditional antidepressants, with minimized adverse effects.

Angiogenesis, the process by which new blood vessels form from existing vasculature, is fundamental to tissue repair and regeneration but also underlies pathological conditions such as cancer progression. Targeting angiogenesis has thus become a promising approach for developing novel cancer therapeutics. While various phytochemicals have demonstrated anti-angiogenic effects, the role of 2-5(H)-Furanone, a naturally occurring lactone found in various plants and marine sources with diverse biological activities, remains insufficiently explored. In this study, we systematically evaluate the anti-angiogenic potential of 2-5(H)-Furanone using Human Umbilical Vein Endothelial Cells (HUVECs) as an in vitro model and zebrafish embryos as an in vivo model. Experimental findings demonstrated that treatment of HUVECs with increasing concentrations of 2-5(H)-Furanone led to significant, dose-dependent reductions in proliferation, invasion, migration, and tube formation. Analyses of gene expression revealed marked downregulation of key pro-angiogenic mediators, VEGF, and HIF-1. Complementing these in vitro results, in vivo studies in zebrafish embryos showed robust, dose-dependent inhibition of intersegmental vessel (ISV) formation, accompanied by suppression of critical angiogenesis-related genes. Molecular docking further supported these observations by indicating stable binding of 2-5(H)-Furanone to major angiogenic targets, including VEGFR2, MMP2, HIF-1, and PIK3CA. Collectively, our data demonstrate that 2-5(H)-Furanone potently inhibits angiogenesis, as evidenced in both HUVEC and zebrafish models, through functional and molecular mechanisms. These findings support the further development of 2-5(H)-Furanone as a promising anti-angiogenic therapy candidate.

The emergence of antimicrobial resistance (AMR) has driven the search for alternative therapeutic strategies, including antivirulence approaches targeting bacterial quorum sensing (QS). Azelaic acid (AzA), a naturally occurring dicarboxylic acid with known antimicrobial properties, has not previously been characterized as a QS inhibitor in Gram-negative pathogens. This study evaluated the dual antimicrobial and antivirulence activity of AzA against reference strains and clinical isolates of Pseudomonas aeruginosa, Enterobacteriaceae, and Staphylococcus aureus through in vitro assays and molecular docking analyses. Minimum inhibitory concentration (MIC) values ranged from 250 to 1000 {micro}g/mL, with lower MICs observed in clinical isolates of E. coli and S. aureus. Subinhibitory concentrations (250, 500 and 750 {micro}g/mL) were used to assess QS-regulated virulence factors in P. aeruginosa, including pyocyanin, elastase, alginate, and protease production. AzA exhibited a significant, dose-dependent inhibition of all evaluated virulence factors across both reference and multidrug-resistant (MDR) and pan-drug-resistant (PDR) clinical strains (p < 0.001), achieving inhibition levels exceeding 90% in several cases, particularly for protease activity. Molecular docking analyses revealed that AzA interacts with key QS-related proteins (LasI, LasR, PqsD, and PqsR), showing moderate binding affinities (-5.3 to -6.5 kcal/mol) and stable interactions within conserved ligand-binding domains. These findings suggest a multitarget modulatory mechanism affecting interconnected QS pathways. Overall, this study demonstrates, for the first time, that AzA acts as a quorum sensing inhibitor in P. aeruginosa, attenuating virulence without directly affecting bacterial growth, highlighting its potential as a promising antivirulence therapeutic strategy.

Rapid quantification of sulfur-containing amino acids, particularly cysteine, in legumes is critical for assessing nutritional quality, supporting breeding program screening, and ensuring consistency in quality control processes. However, conventional methods, such as high-performance liquid chromatography (HPLC), are time-consuming and resource-intensive for high-throughput applications. This study evaluated artificial intelligence models for predicting cysteine concentration from surface-enhanced Raman spectroscopy (SERS) spectra of pea extracts. SERS spectra were acquired from 20 cultivars grown at three geographically distinct locations, with HPLC-measured cysteine concentrations as a ground truth reference. Linear regression, partial least squares regression, support vector regression, random forest regression, and a one-dimensional convolutional neural network (1D-CNN) were compared using within-cultivar splits and leave-one-cultivar-out (LOCO) evaluation. The 1D-CNN achieved RMSE 0.008 g/100 g within cultivars and maintained performance under LOCO, while other models showed limited generalization. Shapley Additive Explanations highlighted informative bands in the 630-760 cm-1 range, and noise modeling optimized scan-count selection.

Bacterial microcompartments (BMCs) are proteinaceous organelles that spatially organize metabolic reactions in bacteria and represent an attractive scaffold for pathway engineering. Here, we present a proof-of-concept in vitro study demonstrating a simple, scalable, and modular BMC shell-based platform for enzyme encapsulation using the SpyCatcher-SpyTag (SC-ST) covalent conjugation system. To evaluate the generality of this approach, 16 dehydrogenases were selected, of which 13 were successfully expressed and purified as SC-tagged enzymes in E. coli by five research groups working in parallel. Twelve of these efficiently conjugated to ST-fused BMC-T1 proteins, and addition of urea-solubilized BMC-H triggered rapid self-assembly of HT1 shells, resulting in successful encapsulation of all conjugated enzymes. The only enzyme lacking detectable activity after encapsulation was also inactive in its free SC-fused form, indicating that encapsulation retained enzymatic activity for all tested enzymes. Encapsulation modulated enzymatic activity and kinetic parameters in an enzyme-dependent manner, likely arising from variations in catalytic mechanism, structural flexibility affected by immobilization, and sensitivity to the local microenvironment created by encapsulation. Functional characterization of a subset of encapsulated enzymes revealed enhanced thermal stability up to [~]50 {degrees}C and improved storage stability relative to free SC-fused enzymes. Enzyme-loaded shells could be lyophilized and reconstituted without loss of structural integrity or activity. Finally, we demonstrate co-encapsulation of two enzymes within a single shell and their cooperative function through cofactor recycling. Together, these results establish engineered BMCs as a robust and modular platform for organizing multi-enzyme pathways, enabling rapid assembly, stabilization, and functional integration of enzymes for diverse metabolic engineering applications. HighlightsA single strategy enables encapsulation of 12 diverse dehydrogenases in BMCs. SpyCatcher-SpyTag interactions drive rapid enzyme assembly in BMCs. Encapsulated enzymes are active and show improved thermal stability. The platform enables scalable construction of synthetic metabolic modules. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=78 SRC="FIGDIR/small/712704v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@1e56ffborg.highwire.dtl.DTLVardef@1ac8b5org.highwire.dtl.DTLVardef@6f23c1org.highwire.dtl.DTLVardef@945c54_HPS_FORMAT_FIGEXP M_FIG C_FIG

Lanthipeptides represent the largest group of ribosomally synthesized and post-translationally modified peptides (RiPPs). Lanthipeptides offer promising avenues for discovering new antibacterial and antifungal agents. Here, we identify and structurally analyze the product of the tla BGC, which encodes a class II lanthipeptide in the thermophilic bacterium Thermoactinomyces sp. DSM 45891. Heterologous co-expression of the lanthipeptide synthetase TlaM resulted in modification of the two precursor peptides TlaA1 and TlaA2, which share 58% identity. TlaA1 was dehydrated seven times and TlaA2 six times. In both peptides, four thioether rings were formed with two overlapping DL-(methyl)lanthionine rings at the C-terminus. Both peptides also contain two central and N-terminal non-overlapping DL-methyllanthionines. These findings demonstrate that these peptides deviate from the general rule of stereoselective LL-(methyl)lanthionine formation from a DhxDhxXxxXxxCys motif (Dhx = dehydroalanine or dehydrobutyrine). AspN-cleaved TlaM-modified TlaA1 displayed anti-microbial activity against a subset of bacteria including Gram-negative ESKAPE pathogens. We named the lantibiotic thermolanthin.

Sirtuins (SIRTs), which remove protein lysine acyl modifications, play crucial roles in diverse cellular processes, including metabolism, gene transcription, DNA damage repair, cell survival, and stress response. Several sirtuins are considered non-oncogene addiction of cancer cells and promising targets for anticancer drug development. High-throughput screening (HTS) methods for sirtuins are critical for the development of potent and isoform-selective sirtuin inhibitors, which are needed to validate the therapeutic potential. Herein, we designed and synthesized a fluorescent polarization (FP) tracer, KP-SC-1. Using this high-affinity tracer, we developed a robust, high-throughput FP competition assay for screening SIRT1-3 inhibitors. The assay was validated by testing known SIRT1-3 inhibitors. The assay can detect NAD+-independent SIRT1-3 inhibitors, as well as NAD+-dependent inhibitors, such as Ex-527 and TM. Finally, our assay showed satisfactory stability and outstanding performance in a pilot library screening. Compared to previous assays, the FP assay uses much less SIRT1-3 enzymes, a feature important for high-throughput library screening. We believe that the FP assay developed here will accelerate the discovery and development of SIRT1-3 inhibitors.

Inositols are a family of cyclic sugar alcohols comprising nine stereoisomers. Myo-inositol is the most abundant isomer found in humans and has been studied most extensively. It plays an important role in osmoregulation and is incorporated into membrane-anchored phosphatidylinositols. Scyllo-inositol is the second most abundant inositol isomer in the human brain and aberrant concentrations are associated with various diseases; however, its biological functions remain poorly understood. Here, the development and application of [13C6]scyllo-inositol as an isotopic tracer to study its metabolism is reported. A concise and robust synthetic route was established to obtain [13C6]scyllo-inositol from [13C6]myo-inositol in good yield. The uptake of [13C6]scyllo-inositol and responses of endogenous inositol isomers were measured in multiple cell lines by HILIC-MS/MS, showcasing the advantages of isotopic tracing. [13C6]scyllo-inositol proved to be a versatile isotopic tracer, when coupled with MS-based lipidomics and 2D NMR experiments. These experiments provide evidence that scyllo-inositol is incorporated into phosphatidylinositols in different cell lines. The results suggest a previously underappreciated role of scyllo-inositol in mammalian cells. The utilization of [13C6]scyllo-inositol will help to elucidate the role of scyllo-inositol metabolism in healthy and diseased states. SignificanceScyllo-inositol is a cyclic sugar alcohol found predominantly in the human brain. Changes in its concentration are associated with different diseases, and scyllo-inositol has been investigated as a potential drug against Alzheimers disease in clinical trials. However, its metabolic fate in mammalian cells is not well understood. We report here a synthetic strategy to obtain [13C6]scyllo-inositol and demonstrate, through isotopic tracing, its incorporation into phosphatidylinositols in different human-derived cell lines. This new stable isotopic tracer enables the investigation of the biological role of scyllo-inositol in mammals and beyond. HighlightsO_LIConcise synthesis of [13C6]scyllo-inositol C_LIO_LI[13C6]scyllo-inositol uptake and response of endogenous inositol isomers studied in multiple cell lines C_LIO_LIUse of [13C6]scyllo-inositol as an isotopic tracer in metabolomics and lipidomics experiments C_LIO_LIEvidence for scyllo-inositol incorporation into phosphatidylinositol in mammalian cells C_LI

Tumour biomarkers such as CA125, CA15-3, CA19-9, AFP and CEA are routinely used in the oncology clinic to diagnose cancer, monitor response to therapy, and detect relapse. However, their quantification depends on immunoassay-based methods that are time-consuming, reagent-dependent, and poorly suited to resource-limited settings. Here, we present a machine learning-assisted ATR-FTIR spectroscopy approach for label-free tumour biomarker analysis to enable simple and rapid quantification at the bedside. Using principal component analysis (PCA), we first demonstrate that these five clinically relevant biomarkers are spectrally separable, with the protein-associated region (1200-1700 cm-1) providing the greatest discriminative information. We then develop partial least squares regression (PLSR) models to quantify CA125 in phosphate-buffered saline (R2 = 0.95) and in human serum across a clinically relevant concentration range, achieving reliable predictions at and above the clinical decision threshold of 35 U/mL. A semi-quantitative classification model further demonstrated robust identification of elevated CA125, with a macro-average sensitivity of 0.86 and specificity of 0.92. These results support ATR-FTIR spectroscopy as a rapid, reagent-free platform for cancer biomarker monitoring, with potential utility in resource-limited settings. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/714840v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@1be9c03org.highwire.dtl.DTLVardef@f49e5eorg.highwire.dtl.DTLVardef@1c93e39org.highwire.dtl.DTLVardef@1141e6f_HPS_FORMAT_FIGEXP M_FIG C_FIG

Age-accompanied chronic, low-grade systemic inflammation (inflammaging) drives the onset and progression of neurodegenerative disorders like Parkinsons disease (PD). Currently, no disease-modifying therapies are available for PD. Exposure to environmental toxicants, including paraquat (PQ), rotenone, and neurotoxic metals, increases disease risk. Conversely, sustained consumption of dietary soft electrophiles, such as flavonoids, carotenoids, vitamin E vitamers, and essential fatty acids, has been associated with increased lifespan and delayed age-related neurological decline. Omega-3 and select omega-6 fatty acids also serve as precursors of lipid-derived specialized pro-resolving mediators (SPMs), which exert potent anti-inflammatory and inflammation-resolving activities. Here, we report the development of a robust analytical method to quantify pro-resolving oxylipins in a PQ-induced Drosophila melanogaster model of PD, enabling investigation of how dietary phytochemicals modulate anti-inflammatory and pro-resolving lipid metabolism in vivo. We hypothesized that plant-derived soft electrophiles promote active resolution of neuroinflammation by enhancing the production of pro-resolving oxylipins derived from essential fatty acids, and that their neuroprotective effects are linked to their soft electrophilic properties. Our results demonstrate that specific lipophilic plant-derived soft electrophiles significantly upregulate pro-resolving oxylipins in Drosophila heads following PQ exposure. We identify a subset of flavones and structurally related phytochemicals that selectively enhance SPM biosynthesis and show that this response involves the NF-{kappa}B orthologue relish. Additionally, feeding modality and sex-specific dimorphisms were found to influence oxylipin production. Collectively, these findings indicate that structurally related dietary soft electrophiles enhance endogenous pro-resolving lipid pathways, promote resolution of toxin-induced neuroinflammation, and have potential preventive and therapeutic relevance for neuroinflammation-associated neurodegenerative diseases. HighlightsO_LIQuantification of pro-resolving lipids in a Drosophila Parkinsons model. C_LIO_LISpecific structural features of phytochemicals contribute to in vivo bioactivity. C_LIO_LILipophilic soft electrophiles show therapeutic potential against neuroinflammation. C_LIO_LIFeeding modality and sexual dimorphism also regulate oxylipin production. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=105 SRC="FIGDIR/small/714080v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@2088cforg.highwire.dtl.DTLVardef@1f5d026org.highwire.dtl.DTLVardef@134aa44org.highwire.dtl.DTLVardef@965e28_HPS_FORMAT_FIGEXP M_FIG C_FIG