Molecules

19 pages, 4086 KB

Open AccessArticle

Comparative Effects of High-Molecular-Weight Chitosan and Chitosan Oligosaccharide Lactate on Metabolic Adjustment and Salinity Tolerance in Cucumis sativus L.

by Barbara Hawrylak-Nowak, Maria Stasińska-Jakubas, Jan Sawicki, Renata Matraszek-Gawron, Weronika Jarmulska, Magdalena Czelej-Wrzesień and Sławomir Dresler

Molecules 2026, 31(18), 3306; https://doi.org/10.3390/molecules31183306 (registering DOI) - 17 Sep 2026

Abstract

Salinity is one of the most harmful abiotic factors limiting crop productivity. Chitosan is a natural polysaccharide biostimulant able to alleviate salt stress, but its efficiency depends on its physicochemical properties, which remain insufficiently understood. The present study aimed to determine whether two [...] Read more.

Salinity is one of the most harmful abiotic factors limiting crop productivity. Chitosan is a natural polysaccharide biostimulant able to alleviate salt stress, but its efficiency depends on its physicochemical properties, which remain insufficiently understood. The present study aimed to determine whether two chemically distinct forms of chitosan, i.e., high-molecular-weight chitosan (ChT) and chitosan oligosaccharide lactate (ChL), differentially mitigate the adverse effects of NaCl-induced salinity in cucumber (Cucumis sativus L.). Plants were grown hydroponically under control conditions or in the presence of 50 mmol L⁻¹ NaCl, with or without medium-applied ChT or ChL (10 mg L⁻¹). Salinity reduced growth and the accumulation of photosynthetic pigments, whereas chlorophyll fluorescence parameters remained largely unaffected, indicating limited impairment of PSII photochemistry. Chitosan, particularly the ChT form, partially alleviated NaCl-induced growth inhibition; ChT increased shoot and root fresh weight and leaf area under salt stress, whereas the effects of ChL were not statistically significant. Chitosan also enhanced free proline accumulation and was associated with changes in selected tricarboxylic acid (TCA) cycle intermediates, particularly malate and α-ketoglutarate, indicating an association with altered central carbon metabolism under salt stress. In contrast, neither chitosan form substantially improved the ionic status of cucumber, as excessive Na accumulation and reductions in K concentration and the K/Na ratio persisted despite treatment. These findings suggest that the beneficial effects of chitosan, particularly ChT, in salt-stressed cucumber were associated more closely with metabolic and osmotic responses than with restoration of ion homeostasis or direct protection of the photosynthetic apparatus, with the two chitosan forms showing different response patterns under the experimental conditions used. Full article

(This article belongs to the Special Issue Green Chemistry and Molecular Tools in Agriculture)

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17 pages, 3343 KB

Open AccessArticle

Structural Characterization of Ettringite Synthesized in the Presence of Arsenate(V) and Chromate(VI) Ions

by Magdalena Król, Witold Jastrzębski and Włodzimierz Mozgawa

Molecules 2026, 31(18), 3305; https://doi.org/10.3390/molecules31183305 (registering DOI) - 17 Sep 2026

Abstract

Ettringite (Ca₆[Al(OH)₆]₂(SO₄)₃⋅26H₂O) is an important hydration product involved in the immobilization of oxyanion contaminants in cementitious systems; however, the structural effects of arsenate(V) and chromate(VI) incorporation remain poorly understood. This study [...] Read more.

Ettringite (Ca₆[Al(OH)₆]₂(SO₄)₃⋅26H₂O) is an important hydration product involved in the immobilization of oxyanion contaminants in cementitious systems; however, the structural effects of arsenate(V) and chromate(VI) incorporation remain poorly understood. This study investigates the influence of both oxyanions on the formation and structure of ettringite-based materials using X-ray diffraction (XRD) with Rietveld refinement and Fourier-transform infrared spectroscopy (FT-IR). Ettringite remained the dominant crystalline phase in all samples, with no detectable secondary crystalline compounds. Chromate incorporation caused only minor changes in lattice parameters, whereas arsenate addition resulted in a decrease in unit cell volume, mainly due to contraction along the c axis. FT-IR analysis confirmed preservation of the ettringite framework and revealed local structural modifications, particularly for arsenate-bearing samples. The results indicate that the presence of both oxyanions is associated with structural changes in ettringite-bearing materials, with arsenate causing a stronger structural response within the investigated compositional range. Full article

(This article belongs to the Special Issue Recent Research Progress of Novel Ion Adsorbents—2nd Edition)

14 pages, 799 KB

Open AccessArticle

Leptospermum scoparium Essential Oil: Antibacterial Properties, Cyto/Genotoxic Effects, Antioxidant Activity, and Wound-Healing Potential In Vitro

by Mária Bučková, Andrea Puškárová, Dominika Galová, Marek Straka, Magda Suchánková, Domenico Pangallo, Monika Šramková and Katarína Kozics

Molecules 2026, 31(18), 3304; https://doi.org/10.3390/molecules31183304 (registering DOI) - 17 Sep 2026

Abstract

This study evaluated Leptospermum scoparium, (manuka) essential oil (LSEO, for its antibacterial activity, cyto/genotoxicity, antioxidant potential, and its effects on wound closure, reflecting the growing interest in natural compounds with antimicrobial and potential wound-related cellular effects. Analyses were performed on the human [...] Read more.

This study evaluated Leptospermum scoparium, (manuka) essential oil (LSEO, for its antibacterial activity, cyto/genotoxicity, antioxidant potential, and its effects on wound closure, reflecting the growing interest in natural compounds with antimicrobial and potential wound-related cellular effects. Analyses were performed on the human keratinocyte cell line HaCaT. The genotoxic effect and the scratch assay of LSEO on human keratinocytes are described for the first time. The results revealed that LSEO did not induce significant DNA damage in vitro after 24 h of treatment. Moreover, treating HaCaT cells with LSEO increased the total antioxidant status level and enhanced wound closure at a concentration of 0.008 µg/mL. Additionally, the inhibitory effect of LSEO against several multidrug-resistant bacterial strains, including Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli, Enterobacter cloacae, and Staphylococcus aureus, was investigated. LSEO exhibited strong antibacterial activity, with inhibition zones ranging from 25 to 44 mm. The minimal inhibitory concentration and minimal bactericidal concentration of LSEO ranged from 0.10 to 0.5 μg/mL and from 0.25 to 0.75 μg/mL, respectively. The findings indicate that LSEO exhibits antibacterial activity against the tested multidrug-resistant bacterial isolates and may warrant further investigation as a potential antimicrobial agent. Full article

(This article belongs to the Special Issue Bioactive Compounds: Applications and Benefits for Human Health, 2nd Edition)

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19 pages, 1620 KB

Open AccessArticle

Astaxanthin–Turmeric–Honeysuckle Extract Combination Attenuates DSS-Induced Colitis with Preservation of the Epithelial Barrier and Reduced NLRP3/Caspase-1/GSDMD Signaling

by Zhongting Lv, Xuan Liu, Yong Pang, Jie Zhang and Li Ren

Molecules 2026, 31(18), 3303; https://doi.org/10.3390/molecules31183303 (registering DOI) - 17 Sep 2026

Abstract

Inflammatory bowel disease is characterized by recurrent mucosal inflammation, epithelial barrier disruption, and dysregulated cell death, highlighting the need for safe, multi-target interventions. Natural astaxanthin, renewably sourced from Haematococcus pluvialis or Phaffia rhodozyma, has shown greater tissue accumulation or antioxidant activity than [...] Read more.

Inflammatory bowel disease is characterized by recurrent mucosal inflammation, epithelial barrier disruption, and dysregulated cell death, highlighting the need for safe, multi-target interventions. Natural astaxanthin, renewably sourced from Haematococcus pluvialis or Phaffia rhodozyma, has shown greater tissue accumulation or antioxidant activity than synthetic astaxanthin in some preparations. Based on the complementary antioxidant, anti-inflammatory, and intestinal barrier-protective activities of its individual components, the astaxanthin–turmeric extract–honeysuckle extract combination (ATH) was investigated for its protective effects in a mouse model of dextran sulfate sodium (DSS)-induced colitis. Thirty-two male C57BL/6J mice were randomly allocated to four cohorts: Control, DSS, DSS + ATH, and ATH. ATH intervention mitigated the DSS-associated decline in body mass, lowered clinical disease scores, attenuated DSS-induced colon shortening, and ameliorated mucosal lesions. In DSS-treated mice, ATH attenuated goblet-cell loss, reduced intestinal permeability, and restored ZO-1 and occludin expression. ATH treatment also reduced DSS-induced increases in colonic IL-1β, IL-6, TNF-α, IL-18, and malondialdehyde levels while improving superoxide dismutase activity and glutathione content. At the signaling level, ATH reduced phosphorylated NF-κB and NLRP3 immunoreactivity and decreased N-GSDMD accumulation within E-cadherin-positive epithelial regions. Western blotting further showed reduced NLRP3 expression, caspase-1 cleavage, and N-GSDMD formation, although the p-NF-κB/NF-κB ratio was not significantly changed. Collectively, ATH alleviated DSS-induced colitis by improving mucosal barrier and redox–inflammatory homeostasis while attenuating the NLRP3/caspase-1/GSDMD pyroptotic cascade. These findings support the further development of ATH as a multi-component natural intervention for intestinal inflammatory injury. Full article

(This article belongs to the Special Issue Pharmacological, Metabolic and Toxicological Profiling of Xenobiotics)

31 pages, 2890 KB

Open AccessArticle

Glycine and Glucose Exert Divergent Concentration-Dependent Interfacial Regulatory Effects on Goethite-Catalyzed Polyphenol–Maillard Abiotic Humification

by Nan Wang, Zihan Zheng, Mingshuo Wang, Jiawen Peng, Houfu Chen and Shuai Wang

Molecules 2026, 31(18), 3302; https://doi.org/10.3390/molecules31183302 (registering DOI) - 17 Sep 2026

Abstract

Iron oxide-mediated abiotic humification is critical for long-term soil organic carbon (SOC) stabilization. Goethite (α-FeOOH), the most thermodynamically stable iron oxyhydroxide in terrestrial ecosystems, is proposed to catalyze coupled Maillard reaction and polyphenol oxidation via surface hydroxyl and Fe(III) active sites. Nevertheless, the [...] Read more.

Iron oxide-mediated abiotic humification is critical for long-term soil organic carbon (SOC) stabilization. Goethite (α-FeOOH), the most thermodynamically stable iron oxyhydroxide in terrestrial ecosystems, is proposed to catalyze coupled Maillard reaction and polyphenol oxidation via surface hydroxyl and Fe(III) active sites. Nevertheless, the divergent interfacial regulatory mechanisms of glycine (Gly, N source) and glucose (Glu, C source) concentration gradients in goethite-catalyzed polyphenol-Maillard systems remain poorly understood. Two independent 360-h gradient incubation experiments were performed using synthetic goethite as a catalyst and catechol as a model polyphenol precursor to probe their concentration-dependent effects on short-term interfacial transformation kinetics and humic-like product properties. Kinetics, product properties, and underlying pathways were characterized via Gaussian and first-order asymptotic modeling, humic-like acid (HLA)/fulvic-like acid (FLA) fractionation, elemental analysis, Fourier-transform infrared (FTIR) spectroscopy, and partial least squares structural equation modeling (PLS-SEM). Results showed that 0.12 mol/L was the optimal concentration for both precursors to accelerate intermediate transformation. Gly elevated the baseline aromaticity parameter y₀ by 108.87% (vs. 20.38% for Glu), while Glu increased the asymptotic maximum dissolved organic carbon (DOC) by 322.66% (vs. 78.02% for Gly). Moderate Gly (0.03 mol/L) yielded the highest C_HLA. Excessive precursors reduced the C_HLA/C_FLA ratio via interfacial competitive adsorption and site occupation. The two precursors exerted opposing effects on the hydroxyl stretching peak of humic products, but both induced goethite surface reconstruction and activated iron-bearing surface functional groups. PLS-SEM confirmed precursor concentration as the dominant driver of humification kinetics. This study clarifies the distinct roles of Gly in aromatic cyclization and Glu as an aliphatic C donor during short-term mineral–organic interfacial processes, providing quantitative benchmarks for optimizing artificial humus production. Full article

(This article belongs to the Section Organic Chemistry)

9 pages, 949 KB

Open AccessCommunication

1,4-Benzo[b]dithiine Derivatives Accessed via Ring Expansion of 1,3-Dithioles

by Dawid T. Leja, Wojciech J. Depa, Maja Morawiak, Agata Bajek-Bil, Jaromir B. Lechowicz and Grażyna Groszek

Molecules 2026, 31(18), 3301; https://doi.org/10.3390/molecules31183301 (registering DOI) - 17 Sep 2026

Abstract

Herein, we disclose an efficient route to the synthesis of 2-bromobenzo[b][1,4]dithiines from benzo[d][1,3]dithioles via ring expansion by introducing a carbon fragment of methyl or methylene groups into the heterocyclic rings promoted by bromine (51–94%). The use of a methyl [...] Read more.

Herein, we disclose an efficient route to the synthesis of 2-bromobenzo[b][1,4]dithiines from benzo[d][1,3]dithioles via ring expansion by introducing a carbon fragment of methyl or methylene groups into the heterocyclic rings promoted by bromine (51–94%). The use of a methyl substituent on an aromatic ring leads to the formation of an inseparable, equimolar mixture of regioisomers. Additionally, a 4-methoxyacetophenone derivative yielded unprecedented dimeric products, whose structure was confirmed by single-crystal X-ray crystallography. We propose a reaction mechanism, rationalizing the formation of the observed regioisomers. Full article

(This article belongs to the Special Issue Organosulfur Compounds)

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24 pages, 6698 KB

Open AccessArticle

Green Synthesis of Silver Nanoparticles from Melissa officinalis Flower: Evaluation of Antimicrobial, Antioxidant, and Photocatalytic Activity

by Emre Erden Kopar

Molecules 2026, 31(18), 3300; https://doi.org/10.3390/molecules31183300 - 17 Sep 2026

Abstract

Silver nanoparticles (AgNPs) synthesized via green approaches have attracted considerable attention because of their eco-friendly production and versatile biological and photocatalytic properties. In this study, Melissa officinalis flower extract was employed as a natural reducing, capping, and stabilizing agent for the green synthesis [...] Read more.

Silver nanoparticles (AgNPs) synthesized via green approaches have attracted considerable attention because of their eco-friendly production and versatile biological and photocatalytic properties. In this study, Melissa officinalis flower extract was employed as a natural reducing, capping, and stabilizing agent for the green synthesis of AgNPs. HPLC-DAD analysis revealed that the flower extract exhibited a diverse phytochemical profile, including phenolic acids and flavonoids, which may contribute to the reduction of Ag⁺ ions and the stabilization of the synthesized AgNPs. The synthesized nanoparticles were characterized using UV–Vis spectroscopy, ATR-FTIR, SEM, DLS, zeta potential analysis, and XRD. The AgNPs exhibited predominantly spherical to hemispherical morphology with an average particle size of 40 nm and a characteristic surface plasmon resonance peak at 414 nm. DLS analysis revealed a particle size of 111.2 nm and a Z-average hydrodynamic diameter of 296.0 nm, while the zeta potential of −73.2 mV suggested high colloidal stability. XRD analysis confirmed the formation of a face-centered cubic (fcc) crystalline structure. The synthesized AgNPs exhibited photocatalytic activity, achieving degradation efficiencies of 93.6 ± 0.3% for methylene blue and 44.8 ± 0.6% for Coomassie Brilliant Blue R-250 after 180 min. In addition, the nanoparticles exhibited considerable antioxidant activity in the DPPH assay and antimicrobial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Candida albicans. Overall, the findings indicate that AgNPs synthesized from M. officinalis flowers via the green synthesis method exhibited photocatalytic, antioxidant, and antimicrobial activities under the experimental conditions studied. These findings suggest that the synthesized AgNPs could be considered a potential material, particularly for dye removal and antimicrobial applications. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Green Chemistry)

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17 pages, 6391 KB

Open AccessArticle

Intramolecular H−Migration Kinetics of •OOQOOH Radicals for KHP Formation During Low-Temperature Oxidation of Alkylcyclohexanes

by Xiaoxia Yao, Yuheng Liu, Ying Xuan, Junjiang Guo, Mingxia Liu, Zerong Li and Wenjiong Hai

Molecules 2026, 31(18), 3299; https://doi.org/10.3390/molecules31183299 - 17 Sep 2026

Abstract

Alkylcyclohexanes are vital components of aviation kerosene. Intramolecular H−migration of •OOQOOH radicals controls ketohydroperoxide (KHP) formation, the primary pathway responsible for low-temperature chain-branching during low−temperature oxidation. Available chemical kinetic models for alkylcyclohexanes generally lack directly computed kinetic data for H−migration reactions of •OOQOOH [...] Read more.

Alkylcyclohexanes are vital components of aviation kerosene. Intramolecular H−migration of •OOQOOH radicals controls ketohydroperoxide (KHP) formation, the primary pathway responsible for low-temperature chain-branching during low−temperature oxidation. Available chemical kinetic models for alkylcyclohexanes generally lack directly computed kinetic data for H−migration reactions of •OOQOOH in cyclic fuels; relevant rate constants are commonly transferred from analogous alkane reactions, introducing systematic uncertainties in low−temperature ignition predictions. In this work, quantum chemical calculations are performed for 13 representative •OOQOOH intramolecular H−migration pathways originating from alkylcyclohexanes, covering six structural subclasses: 1,5−H−(s)(p), 1,5−H−(s)(s), 1,5−H−(t)(p), 1,5−H−(t)(s), 1,6−H−(t)(p), and 1,6−H−(t)(s). Modified Arrhenius parameters are fitted from high−pressure−limit rate constants over 500–1500 K. Further comparison between the present computed rate data and parameters adopted in existing mechanisms demonstrates that the literature values transferred from alkanes are systematically lower. Ring strain and distinct transition−state entropy originating from cyclic structures make the alkane kinetic parameters inappropriate for alkylcyclohexane systems. The kinetic parameters and lumped subclass rate rules obtained in this study provide fundamental data for improving low-temperature oxidation models of alkylcyclohexanes. Full article

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36 pages, 3624 KB

Open AccessArticle

Enhancing the Phenolic Value of Polyphenol-Rich Extra Virgin Olive Oils Through Optimized Water Extraction, Macroporous Resin Recovery and Spray Drying

by Athanasios Gerasopoulos, Kyriakos Kachrimanis and Diamanto Lazari

Molecules 2026, 31(18), 3298; https://doi.org/10.3390/molecules31183298 - 17 Sep 2026

Abstract

Olive oil polyphenols are well-established for their health-promoting properties. A recently emerged polyphenol-rich extra virgin olive oil (EVOO) was subjected to a water extraction process, optimized using response surface methodology (RSM). The effects of salt content and the water-to-oil ratio on the total [...] Read more.

Olive oil polyphenols are well-established for their health-promoting properties. A recently emerged polyphenol-rich extra virgin olive oil (EVOO) was subjected to a water extraction process, optimized using response surface methodology (RSM). The effects of salt content and the water-to-oil ratio on the total phenolics were initially evaluated. Maximal phenolic yield was obtained by a water/EVOO ratio of 9.6:1 (v:v) and 0% added salt, although the addition of 3% salt provided an oil-free extract with a satisfactory phenolic yield compared to the optimized extract. Further, the phenolics of the optimized water extract were recovered using macroporous XAD resins. XAD-7HP resin and 75% ethanol/water eluent were selected based on comparatively improved adsorption/desorption and recovery data. Recovered phenolics were then encapsulated using spray drying and a maltodextrin carrier; the resulting powder was evaluated for physical and phenolic release properties. Phenolic composition was measured in all stages using ¹H-NMR, revealing a phenolic yield of 39% in the extraction step, which was reduced through recovery and encapsulation to 25%; oleocanthal and oleacein were partitioned from olive oil to water extract by 55–50% while oleuropein and ligstroside aglycones only by 14.5–31.7%. The compositional pattern of water-extracted phenolics remained the same throughout recovery and encapsulation. These findings contribute to a moderately efficient, green procedure in developing innovative nutraceutical supplements/functional food ingredients. Full article

(This article belongs to the Special Issue Green Extraction and Advanced Characterization Methods for Bioactive Compounds in Food and By-Products)

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16 pages, 2054 KB

Open AccessReview

Ginsenoside Rg2 from Panax spp.: Diverse Biological Activities, Mechanisms and Prospect

by Jiahui Lu, Ruomeng Li, Rui Liu, Lanqi Liu, Biyu Lan, Zehua Wang and Guizhen Wang

Molecules 2026, 31(18), 3297; https://doi.org/10.3390/molecules31183297 - 17 Sep 2026

Abstract

As a well-known medicinal and edible traditional Chinese medicine, ginseng is rich in diverse active ingredients and exerts broad pharmacological effects. Among them, ginsenoside Rg2 (Rg2) has become a research hotspot due to its notable biological activities. Rg2 exhibits multiple pharmacological activities, including [...] Read more.

As a well-known medicinal and edible traditional Chinese medicine, ginseng is rich in diverse active ingredients and exerts broad pharmacological effects. Among them, ginsenoside Rg2 (Rg2) has become a research hotspot due to its notable biological activities. Rg2 exhibits multiple pharmacological activities, including myocardial protection, nervous system regulation, and anti-inflammation, anti-tumor, and anti-oxidative stress effects, by regulating multiple signaling pathways such as AKT, MAPK-ERK, and NF-κB/NLRP3. It also shows favorable biological functions in protecting against pregnancy-related brain injury, intervening in osteoporosis, delaying muscle atrophy, regulating metabolism, and modulating immunity, with preliminary oral safety profiles reported in rodent studies. This paper provides a narrative overview of the research progress on the pharmacological effects and mechanisms of Rg2, with the aim of offering a theoretical foundation for the development of natural drugs and the utilization of ginseng, as well as a reference for clinical trials and combination therapy strategies. Full article

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19 pages, 4148 KB

Open AccessArticle

Alantolactone Activates the Extracellular Signal-Regulated Kinase Signaling Pathway to Promote Tumor Necrosis Factor Receptor 1 Ectodomain Shedding

by Piimwara Yarangsee, Quy Van Vu, Yasunobu Miyake and Takao Kataoka

Molecules 2026, 31(18), 3296; https://doi.org/10.3390/molecules31183296 - 17 Sep 2026

Abstract

Alantolactone is a sesquiterpene lactone that possesses anticancer and anti-inflammatory properties. We previously demonstrated that several sesquiterpenes, including alantolactone, induced the ectodomain shedding of tumor necrosis factor receptor 1 (TNF-R1). In the present study, we investigated the upstream signaling pathway underlying alantolactone-induced TNF-R1 [...] Read more.

Alantolactone is a sesquiterpene lactone that possesses anticancer and anti-inflammatory properties. We previously demonstrated that several sesquiterpenes, including alantolactone, induced the ectodomain shedding of tumor necrosis factor receptor 1 (TNF-R1). In the present study, we investigated the upstream signaling pathway underlying alantolactone-induced TNF-R1 ectodomain shedding. Alantolactone down-regulated the expression of full-length TNF-R1 on the cell surface of human lung adenocarcinoma A549 cells, and this was accompanied by an increase in soluble TNF-R1 in the culture medium. TNF-R1 ectodomain shedding was also detected in human embryonic kidney 293T cells and human fibrosarcoma HT-1080 cells, indicating the conservation of this effect in multiple cell lines. The metalloproteinase inhibitor GM6001 markedly suppressed alantolactone-induced soluble TNF-R1 release and restored cell-surface TNF-R1 expression. Among specific inhibitors targeting mitogen-activated protein kinase (MAPK) signaling pathways, TNF-R1 ectodomain shedding was markedly suppressed by the MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor U0126, whereas the suppressive effects of the c-Jun N-terminal kinase (JNK) inhibitor SP600125 or the p38 MAPK inhibitor SB203580 were negligible. Consistent with these results, alantolactone increased phospho-ERK and phospho-RAF1 levels within 60–120 min, while p38 MAPK and JNK were minimally phosphorylated during the 120-min incubation. Collectively, these results indicate that alantolactone-induced TNF-R1 ectodomain shedding is mediated by the activation of the RAF1–ERK signaling pathway. Full article

(This article belongs to the Special Issue Potential of Natural Products as Drug Leads Possessing Antioxidant, Antiaging and Anticancer Properties, 2nd Edition)

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19 pages, 1106 KB

Open AccessReview

Essential Oils of Lamiaceae Species as Promising Sources of Antimycobacterial Agents: Current Insights, Challenges, and Future Perspectives

by Ana Clara Aprotosoaie, Mihaela Lipovanu, Adina Catinca Grădinaru and Anca Miron

Molecules 2026, 31(18), 3295; https://doi.org/10.3390/molecules31183295 - 17 Sep 2026

Abstract

Tuberculosis remains a major global health threat, severely exacerbated by the emergence of multidrug-resistant strains. The bioprospecting of natural matrices for novel, efficacious, and safe antimycobacterial agents represents an important strategy within the drug discovery pipeline. Essential oils (EOs) derived from the Lamiaceae [...] Read more.

Tuberculosis remains a major global health threat, severely exacerbated by the emergence of multidrug-resistant strains. The bioprospecting of natural matrices for novel, efficacious, and safe antimycobacterial agents represents an important strategy within the drug discovery pipeline. Essential oils (EOs) derived from the Lamiaceae family represent a rich reservoir of bioactive constituents, with well-documented antimicrobial properties and broad therapeutic potential. This review evaluates the current state of research regarding the antimycobacterial activity of Lamiaceae EOs, highlighting their efficacy against Mycobacterium tuberculosis resistant phenotypes, mechanism of action, structure-activity relationships, synergistic interactions with conventional antitubercular chemotherapies, and existing translational challenges. EOs from species belonging to genera such as Thymus, Mentha, Ocimum, Salvia, Satureja, Tetradenia, and Zataria showed significant antimycobacterial potency, with minimum inhibitory concentrations (MIC) below 100 μg/mL. The phenolic monoterpenoids thymol and carvacrol, alongside the abietane-type diterpene 6,7-dehydroroyleanone, exhibited notable antimycobacterial activity with MIC values of 0.78–12.5 μg/mL. Carvacrol and thymol disrupted the lipid-rich mycobacterial cell wall, increased bacterial membrane permeability, impaired energy metabolism, and induced oxidative stress. These compounds also exerted dual inhibitory effects on biofilm formation and development, interfered with Rv1258c and Rv0194 efflux pumps, and inhibited chorismate mutase activity. Similarly, 6,7-dehydroroyleanone compromised the integrity of the lipophilic mycobacterial cell envelope, suppressed cell wall biosynthesis, blocked ABC-family efflux transporters, and induced intracellular oxidative stress. Lamiaceae EOs exhibit multi-target antimycobacterial efficacy and hold considerable potential as adjuvants in combination antituberculosis regimens. To facilitate the translation of these natural matrices from bench to bedside, future research should focus on robust microbiological and chemical standardization, pharmacological and toxicological evaluation, and the development of advanced nanoformulations of EOs to optimize bioavailability and mitigate host cytotoxicity. Full article

(This article belongs to the Special Issue Biological Properties of Extracts and Essential Oils from Plants of the Lamiaceae Family: An Updated Perspective)

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1 pages, 130 KB

Open AccessCorrection

Correction: Chen et al. RNA Chemical Modifications in Mammalian Skeletal Muscle Development, Homeostasis, and Disease: Regulatory Mechanisms and Chemical Biology Perspectives. Molecules 2026, 31, 2797

by Dujun Chen, Mailin Gan, Yuhang Lei, Xinyi Wang, Jincheng Zan, Qing Ye, Xiaofeng Zhou, Lei Chen, Yan Wang, Ye Zhao, Li Zhu and Linyuan Shen

Molecules 2026, 31(18), 3294; https://doi.org/10.3390/molecules31183294 - 17 Sep 2026

Abstract

There was an error in the original publication [...] Full article

24 pages, 6203 KB

Open AccessReview

Bridging Nano-Interface Interactions and Organ-Specific Toxicity: A Review of Machine Learning for Nanomaterials Risk Assessment

by Wei Li, Yanfang Liu, Tianqin Wang, Jiana Meng, Yang Huang, Jiajun Ma and Hongwu Zhang

Molecules 2026, 31(18), 3293; https://doi.org/10.3390/molecules31183293 - 17 Sep 2026

Abstract

Risk assessment of engineered nanomaterials (ENMs) is essential for protecting human health and the environment. Traditional hazard assessments rely primarily on in vivo testing, which faces technical challenges in extrapolation validity, ethical dilemmas, and high costs. Machine learning (ML) models offer alternative approaches [...] Read more.

Risk assessment of engineered nanomaterials (ENMs) is essential for protecting human health and the environment. Traditional hazard assessments rely primarily on in vivo testing, which faces technical challenges in extrapolation validity, ethical dilemmas, and high costs. Machine learning (ML) models offer alternative approaches that are aligned with the 3R principles (Replacement, Reduction, and Refinement) for reducing animal use. ML methods help address the economic, ethical, and temporal limitations of traditional nanotoxicology while advancing mechanistic understanding. This review presents a cross-scale framework integrating nano–bio/nano–environmental interfaces, organ-specific toxicity, in vitro-to-in vivo extrapolation (IVIVE), interpretable ML, and regulatory translation. Future directions include building comprehensive databases to replace sparse literature data, developing ML models that bridge in vitro and in vivo nanotoxicity, incorporating co-exposure scenarios of nanomaterials and chemicals, and further exploring protein/lipid corona formation and structures. Full article

(This article belongs to the Section Nanochemistry)

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29 pages, 2968 KB

Open AccessArticle

GC-MS Profiling, Antioxidant and Enzyme Inhibitory Activities of Basil (Ocimum basilicum L.) and Clove (Syzygium aromaticum L.) Essential Oils and Their Binary Mixtures

by Hubert Sytykiewicz, Iwona Łukasik and Sylwia Goławska

Molecules 2026, 31(18), 3292; https://doi.org/10.3390/molecules31183292 - 17 Sep 2026

Abstract

Combining essential oils (EOs) with contrasting chemical profiles may result in biological effects that cannot be reliably predicted from the properties of the individual oils. This study evaluated the chemical composition, biological activities, and interactions of basil (Ocimum basilicum L.; EOB) and [...] Read more.

Combining essential oils (EOs) with contrasting chemical profiles may result in biological effects that cannot be reliably predicted from the properties of the individual oils. This study evaluated the chemical composition, biological activities, and interactions of basil (Ocimum basilicum L.; EOB) and clove (Syzygium aromaticum L.; EOC) essential oils. Gas chromatography–mass spectrometry (GC-MS) identified 41 volatile constituents in EOB and 29 in EOC. EOB was dominated by estragole (73.0%) and methyl eugenol (7.2%), whereas EOC was characterized mainly by eugenol (55.0%) and (E)-β-caryophyllene (32.9%). The oils were tested individually over a concentration range of 2.5–500 µg/mL, while binary EOB:EOC mixtures (1:1, 1:2, and 2:1; v/v) were evaluated at total essential oil concentrations of 5, 25, and 50 µg/mL. Antioxidant activity was assessed using linoleic acid peroxidation and ABTS^•+ radical scavenging assays, whereas enzyme-inhibitory activity was evaluated against cyclooxygenase-2 (COX-2) and collagenase. EOC showed stronger ABTS^•+ radical scavenging activity and greater inhibition of COX-2 and collagenase, while EOB exhibited greater inhibition of lipid peroxidation. Bliss independence analysis revealed concentration- and ratio-dependent interactions. Synergy (ΔBliss > +10 percentage points) was observed for the 1:2 EOB:EOC mixture at 5 and 25 µg/mL in the COX-2, collagenase, and ABTS^•+ assays, and for all three mixture ratios at 5 µg/mL in the lipid peroxidation assay; no antagonistic interactions were detected. These findings demonstrate that the biological activity and interaction profiles of basil–clove essential oil mixtures depend on both mixture composition and concentration. Further studies in cell-based and in vivo models are required to confirm their efficacy, mechanisms of action, and safety. Full article

(This article belongs to the Special Issue Essential Oils: Chemical Characterization, Bioactivity and Innovative Applications)

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30 pages, 10908 KB

Open AccessArticle

Selenium Nanoparticles: Novel Synthesis, Characterization, Polymer Functionalization, and Cytotoxicity In Vitro

by Dhireshan Singh, Aliscia Nicole Daniels, Mario Ariatti and Moganavelli Singh

Molecules 2026, 31(18), 3291; https://doi.org/10.3390/molecules31183291 - 17 Sep 2026

Abstract

Background: Nanotechnology, a multidisciplinary science, has diverse applications in biology, physics, and medicine. SeNPs have only recently been explored. Understanding how modifications to SeNPs affect toxicity is beneficial for therapeutic applications. This study involves a novel one-pot chemical synthesis of SeNPs using biodegradable [...] Read more.

Background: Nanotechnology, a multidisciplinary science, has diverse applications in biology, physics, and medicine. SeNPs have only recently been explored. Understanding how modifications to SeNPs affect toxicity is beneficial for therapeutic applications. This study involves a novel one-pot chemical synthesis of SeNPs using biodegradable precursors, sodium selenite and ascorbic acid, at predetermined molar ratios, followed by polymer modification. Results: All SeNPs were spherical with favorable sizes (<114 nm) and polydispersity indices (PDI < 0.4). Functionalization improved the zeta potential of the SeNPs (−34.4 to 91.1 mV), together with a smaller size and increased PDI. Cytotoxicity was size-, cell-, dose-, and time-dependent. Functionalized SeNPs showed good cell viability at low concentrations, with toxicity at higher concentrations compared to the unmodified SeNPs. SeNPs synthesized using excess sodium selenite exhibited enhanced toxicity, particularly in neuroblastoma cells. SeNPs induced a significant increase in reactive oxygen species, with G1/G0 cell cycle arrest and apoptosis in human embryonic kidney cells, and necrosis and apoptosis in neuroblastoma and cervical carcinoma cells. Conclusion: The physicochemical and toxicity profiles of SeNPs depend on precursor molar ratios and polymer concentration. Hence, studying the released ions and the polymer-core association will enable the personalized synthesis of SeNPs to achieve the desired therapeutic outcomes. Full article

(This article belongs to the Special Issue Anticancer Drugs: Design, Synthesis, and Anticancer Activity)

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19 pages, 15295 KB

Open AccessArticle

Derivatization-Assisted Lipase-Mediated Separation of Optically Pure α-Cyclopentylmandelic Acid Through Enhanced Substrate Recognition

by Yuhao Zhao, Zhizhi Li, Xianwei Long and Qun Lu

Molecules 2026, 31(18), 3290; https://doi.org/10.3390/molecules31183290 - 17 Sep 2026

Abstract

α-Cyclopentylmandelic acid (CPMA) is a chiral α-hydroxycarboxylic acid valuable in pharmaceutical synthesis and asymmetric catalysis. However, it remains challenging to prepare with high optical purity due to its unique steric structure. This study established a chiral resolution strategy using derivatization-assisted lipase-catalyzed kinetic resolution [...] Read more.

α-Cyclopentylmandelic acid (CPMA) is a chiral α-hydroxycarboxylic acid valuable in pharmaceutical synthesis and asymmetric catalysis. However, it remains challenging to prepare with high optical purity due to its unique steric structure. This study established a chiral resolution strategy using derivatization-assisted lipase-catalyzed kinetic resolution to efficiently prepare optically pure CPMA. We employed acetoxyacetyl chloride derivatization to introduce a diester structure into CPMA that lipase recognizes efficiently and identified recombinant Cal B as the optimal catalyst through enzyme screening. Theoretical calculations suggested that the activity difference resulting from the derivatization strategy stems from spatial recognition rather than electronic effects; the significant difference in binding affinity between the R- and S-substrates provides the driving force for subsequent time-dependent separation. By controlling the reaction time, the (R)- and (S)-CPMA enantiomers could be selectively prepared. This achieved ee values exceeding 99.5% for both enantiomers, with isolated yields over 38% for each. Cal B was immobilized on an ESR carrier and retained good catalytic activity after 12 reuse cycles. The resulting (R)-CPMA was successfully used to synthesize sofpironium bromide, thereby validating the practical feasibility of this process. This strategy provides an effective, environmentally friendly enzymatic route to highly sterically hindered chiral α-hydroxycarboxylic acids. Full article

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28 pages, 1408 KB

Open AccessArticle

Synthesis and Biological Evaluation of 1,3,5-Triazine Derivatives for GPR119 Agonistic Activity

by Bui Hoang Huu Nhan, Seong Ho Jeon, Sujin Lee, Seung Hwan Son, Young Duk Yang and Seok-Ho Kim

Molecules 2026, 31(18), 3289; https://doi.org/10.3390/molecules31183289 - 16 Sep 2026

Abstract

GPR119 is a promising target for the treatment of type 2 diabetes mellitus. Stimulating this receptor leads to the induction of glucose-dependent insulinotropic peptide and glucagon-like peptide 1, which improves systemic glucose homeostasis. Encouraged by our previous research, we replaced 5-nitropyrimidine with 1,3,5-triazine [...] Read more.

GPR119 is a promising target for the treatment of type 2 diabetes mellitus. Stimulating this receptor leads to the induction of glucose-dependent insulinotropic peptide and glucagon-like peptide 1, which improves systemic glucose homeostasis. Encouraged by our previous research, we replaced 5-nitropyrimidine with 1,3,5-triazine to reduce hepatotoxicity. A new series of compounds with a 1,3,5-triazine scaffold was synthesized and evaluated for their agonistic activities against human GPR119. Thirty-three compounds were synthesized and evaluated for their potential GPR119 agonist activities. Analogs with a 4-cyano and a 4-methylsulfonyl group in the aryl ring exhibited more potent activation than those analogs with a 4-trifluoromethyl group. Compound 3c had the most favorable EC₅₀ value (hEC₅₀ = 2.39 µM) and significantly induced glucagon-like peptide-1 secretion. Furthermore, docking simulations showed that compound 3c stably binds to the active site of GPR119. Full article

(This article belongs to the Section Medicinal Chemistry)

19 pages, 1690 KB

Open AccessArticle

Functional Watermelon Jelly Fortified with Potato By-Product-Derived Single-Cell Protein: Antioxidant and Enzyme Inhibitory Potential with Possible Health-Promoting Properties

by Milena Rašeta, Mladen Simonović, Fariddudin Mohammadian, Marko Jovanović, Vladimir Nešić, Maja Karaman, Aleksandra Radulović, Nabil Adrar, Gizem Kezer and Tuba Esatbeyoglu

Molecules 2026, 31(18), 3288; https://doi.org/10.3390/molecules31183288 - 16 Sep 2026

Abstract

Watermelon (Citrullus lanatus) is a widely consumed fruit rich in carotenoids, phenolic compounds, vitamins, and other bioactive constituents associated with antioxidant and health-promoting properties. The present study aimed to develop novel low-sugar watermelon jelly formulations enriched with pectin and single-cell protein [...] Read more.

Watermelon (Citrullus lanatus) is a widely consumed fruit rich in carotenoids, phenolic compounds, vitamins, and other bioactive constituents associated with antioxidant and health-promoting properties. The present study aimed to develop novel low-sugar watermelon jelly formulations enriched with pectin and single-cell protein (SCP), and to evaluate their bioactive and functional properties, including the antioxidant and enzyme inhibitory activities of their 70% ethanol (70% EtOH) extracts. Six jelly formulations (W1–W6) differing in pectin and SCP supplementation were prepared using concentrated watermelon pulp processed under low-temperature vacuum conditions to preserve thermolabile bioactive compounds. The total phenolic content (TPC) and total flavonoid content (TFC) were determined in the 70% EtOH extracts using spectrophotometric methods. TPC remained relatively stable among the investigated formulations, with the highest value recorded for sample W6, which contained 0.58 g pectin and 0.215 g SCP (1.37 mg gallic acid equivalents (GAE)/mL extract). The highest TFC was observed for sample W5, corresponding to the formulation supplemented with 0.5 g pectin and 0.300 g SCP (5.87 mg quercetin equivalents (QE)/mL extract). Antioxidant activity, evaluated using ABTS, DPPH, and FRAP assays, demonstrated considerable antioxidant potential in all 70% EtOH extracts. The strongest antioxidant activity was observed in pectin-rich samples, with ABTS and FRAP values reaching 89.06 mg Trolox equivalents (TE)/mL extract and 8.99 mg ascorbic acid equivalents (AAE)/mL extract, respectively. The potential carbohydrate-hydrolyzing enzyme inhibitory activity of the 70% EtOH extracts was assessed through α-amylase and α-glucosidase inhibition assays. The formulation containing both pectin and SCP exhibited the strongest α-amylase inhibitory activity (58.93%), whereas the highest α-glucosidase inhibition (60.54%) was observed in the pectin-containing formulation without SCP supplementation. These findings indicate that both pectin and SCP significantly influenced the nutritional and bioactive properties of the developed watermelon jelly formulations. Overall, the results demonstrate that enrichment with pectin and SCP significantly enhances the nutritional and bioactive properties of watermelon jelly formulations. These findings highlight indicate that pectin and SCP were associated with differences in the bioactive and functional properties of the developed watermelon jelly formulations. Overall, the results demonstrate the potential of pectin- and SCP-enriched watermelon jellies as sustainable functional food products with promising antioxidant and enzyme inhibitory properties. Full article

(This article belongs to the Section Natural Products Chemistry)

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