Molecules

19 pages, 9255 KB

Open AccessArticle

Impact of Scutellonema curcumae sp. n. (Nematoda: Hoplolaimidae) on the Phytochemical Profile and Biological Activities of Turmeric (Curcuma longa L.)

by Tu Thi Dinh, Quan Minh Pham, Long Quoc Pham, Chi Kim Ngo, Van Thi Thuy Nguyen, Thuong Thi Le Hoang, Tu Ngoc Ly, Linh Ngoc Nguyen, Thao Thi Phuong Nguyen and Lam Tien Do

Molecules 2026, 31(6), 920; https://doi.org/10.3390/molecules31060920 - 10 Mar 2026

Abstract

A new spiral nematode species, Scutellonema curcumae sp. n., was identified from the rhizosphere of turmeric (Curcuma longa L.) in the Western Highlands of Vietnam. Integrative taxonomical analysis, combining detailed morphology and molecular characterization (ITS, 28S D2–D3 rDNA, and COI mtDNA), confirmed [...] Read more.

A new spiral nematode species, Scutellonema curcumae sp. n., was identified from the rhizosphere of turmeric (Curcuma longa L.) in the Western Highlands of Vietnam. Integrative taxonomical analysis, combining detailed morphology and molecular characterization (ITS, 28S D2–D3 rDNA, and COI mtDNA), confirmed its distinctiveness. Scutellonema curcumae sp. n. is characterized by a unique combination of a spiral body, a hemispherical lip region with four annuli, a robust stylet, and a rounded tail with a prominent scutellum, forming a highly divergent lineage within the genus. Beyond its description, this study reveals a significant inverse correlation between nematode population density and the phytochemical quality of the host. High infestation levels were associated with a marked decline in total curcuminoid content. Notably, lower nematode density favored a specific shift in the curcuminoid profile, with bisdemethoxycurcumin levels increasing by up to 250%. These phytochemical alterations directly influenced the therapeutic potential of the rhizomes: lower infestation levels resulted in significantly enhanced antioxidant capacity (lower SC₅₀ values) and cytotoxic activity (lower IC₅₀ against HepG2 and A549 cell lines). This work represents the first report of a Scutellonema species associated with turmeric in Vietnam and underscores its detrimental impact on the medicinal and nutraceutical value of the crop. Our findings suggest that effective nematode management is crucial not only for yield protection but as a strategic intervention in precision agriculture to optimize the secondary metabolite profiles of medicinal plants. Full article

(This article belongs to the Special Issue Natural Products: Isolation, Analysis and Biological Activity, 2nd Edition)

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8 pages, 208 KB

Open AccessEditorial

Health Promoting Compounds in Milk and Dairy Products

by Mena Ritota and Pamela Manzi

Molecules 2026, 31(6), 919; https://doi.org/10.3390/molecules31060919 - 10 Mar 2026

Abstract

Milk represents a fundamental component of the human diet, as it supplies most of the nutrients essential for growth and development [...] Full article

(This article belongs to the Special Issue Health Promoting Compounds in Milk and Dairy Products)

18 pages, 2275 KB

Open AccessFeature PaperArticle

Phytochemical Analysis of Plant Nanophyton iliense U.P. Pratov from Kazakhstan Using LC-MS

by Kudaibergenova Moldir K., Datkhayev Ubaidilla M., Bharathi Avula, Kumar Katragunta, Kiran Kumar Tatapudi, Jennyfer A. Aldana-Mejía, Ikhlas A. Khan, Akhtayeva Nursulu Z., Mukhametzhan Ayala S., Kiyekbayeva Lashyn N. and Samir A. Ross

Molecules 2026, 31(6), 918; https://doi.org/10.3390/molecules31060918 - 10 Mar 2026

Abstract

To date, the phytochemical composition of the aerial parts of Nanophyton iliense U.P. Pratov has not been comprehensively investigated. In the present study, qualitative metabolite profiling of the methanolic extract of the aerial parts was performed using liquid chromatography coupled with diode-array detection [...] Read more.

To date, the phytochemical composition of the aerial parts of Nanophyton iliense U.P. Pratov has not been comprehensively investigated. In the present study, qualitative metabolite profiling of the methanolic extract of the aerial parts was performed using liquid chromatography coupled with diode-array detection and quadrupole time-of-flight mass spectrometry (LC-DAD-QToF-MS) operating in both positive and negative electrospray ionization modes. A total of 81 metabolites were tentatively identified based on accurate mass measurements, MS/MS fragmentation patterns obtained in all-ion MS/MS mode, and comparison with previously reported literature data. The detected compounds included hydroxycinnamic acid amides, phenolic acids, flavonoids (including glycosides), amino acids, organic acids, sulfated derivatives, and nucleosides. Among them, the flavonoid narcissin (isorhamnetin-3-O-rutinoside) was isolated from the extract, and its structure was confirmed by ¹H and ¹³C NMR spectroscopy supported by COSY, HSQC, and HMBC experiments. Additionally, a compound with the molecular formula C₁₇H₁₄O₅ was detected; however, its structure could not be conclusively established based on the available spectroscopic data and is therefore reported as an unidentified metabolite. The present study provides the first systematic qualitative characterization of the metabolite profile of N. iliense and establishes a foundation for future quantitative and bioactivity-oriented investigations of this species. Full article

(This article belongs to the Special Issue Bioactive Compounds from Plants: Identification, Characterization, and Pharmacological Activity)

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26 pages, 7234 KB

Open AccessArticle

Discovery of a Novel Coumarin/Thiazole Chalcone Hybrid as a Potent Dual Inhibitor of Tubulin and Carbonic Anhydrases IX & XII with Promising Anti-Proliferative Activity

by Basima A. A. Saleem, Ashraf A. Qurtam, Mohamed Ahmed, Raed Fanoukh Aboqader Al-Aouadi, Ali Abdulrazzaq Abdulhussein Alrikabi, Helal F. Hetta, Stefan Bräse, Ghallab Alotaibi, Abdullah Alkhammash and Sara Mahmoud Farhan

Molecules 2026, 31(6), 917; https://doi.org/10.3390/molecules31060917 - 10 Mar 2026

Abstract

Multitarget-directed ligands offer a promising strategy for overcoming tumor complexity through simultaneous modulation of complementary oncogenic pathways. In this work, a novel (E)-6-(3-(4-methyl-2-thioxo-2,3-dihydrothiazol-5-yl)-3-oxoprop-1-en-1-yl)-2H-chromen-2-one (compound 6) was synthesized and evaluated as a dual inhibitor of tubulin polymerization and tumor-associated carbonic anhydrases [...] Read more.

Multitarget-directed ligands offer a promising strategy for overcoming tumor complexity through simultaneous modulation of complementary oncogenic pathways. In this work, a novel (E)-6-(3-(4-methyl-2-thioxo-2,3-dihydrothiazol-5-yl)-3-oxoprop-1-en-1-yl)-2H-chromen-2-one (compound 6) was synthesized and evaluated as a dual inhibitor of tubulin polymerization and tumor-associated carbonic anhydrases (CAs) IX and XII. Compound 6 displayed potent antiproliferative activity, particularly against MDA-MB-231 triple-negative breast cancer cells (IC₅₀ = 0.37 µM), with excellent selectivity toward non-tumorigenic cells. Mechanistic studies demonstrated strong tubulin polymerization inhibition (IC₅₀ = 3.40 ± 0.09 µM) and submicromolar inhibition of CA IX (IC₅₀ = 0.102 ± 0.005 µM) and CA XII (IC₅₀ = 0.213 ± 0.004 µM), accompanied by downregulation of CA-IX and CA-XII protein expression. Cellular investigations revealed pronounced G₂/M phase arrest and apoptosis induction via mitochondrial signaling and caspase activation. Anti-angiogenic activity was supported by inhibition of endothelial migration and concentration-dependent suppression of VEGFR-2 (Tyr1175) phosphorylation in HUVEC cells. Human liver microsomal assays indicated measurable metabolic stability, while molecular docking and in silico ADMET predictions supported target engagement and drug-like properties. Collectively, these findings identify compound 6 as a promising multitarget anticancer lead integrating antimitotic, metabolic, and anti-angiogenic mechanisms. Full article

(This article belongs to the Section Medicinal Chemistry)

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21 pages, 934 KB

Open AccessReview

NMR-Based Fragment Screening for RNA-Targeted Drug Discovery

by Riley J. Petersen and Yaqiang Wang

Molecules 2026, 31(6), 916; https://doi.org/10.3390/molecules31060916 - 10 Mar 2026

Abstract

Fragment-based drug discovery (FBDD) has emerged as a primary approach for identifying low molecular weight leads that can be systematically optimized into high-affinity compounds. Because fragments bind inherently weakly, their detection relies on highly sensitive biophysical tools. Nuclear magnetic resonance (NMR) spectroscopy is [...] Read more.

Fragment-based drug discovery (FBDD) has emerged as a primary approach for identifying low molecular weight leads that can be systematically optimized into high-affinity compounds. Because fragments bind inherently weakly, their detection relies on highly sensitive biophysical tools. Nuclear magnetic resonance (NMR) spectroscopy is uniquely qualified for fragment screening due to its capability in detecting weak interactions across a broad affinity range while providing site-specific binding information that supports structure-guided optimization. While FBDD is a mature field for protein targets, structured and disease-relevant RNAs have transitioned from ‘undruggable’ molecules to viable therapeutic targets for small-molecule intervention. Recent studies demonstrate that NMR-based screening can identify authentic RNA binders and guide their evolution into potent, selective ligands. This review summarizes the practical and methodological pipelines for RNA-targeted small molecule NMR screening, covering RNA construct design, sample preparation, and library pooling strategies. We evaluate both ligand- and RNA-observed NMR assays for primary hit screening and validation, integration of NMR restraints with structural modeling, and representative case studies. Finally, we discuss current bottlenecks in the field and highlight emerging strategies to accelerate the discovery of RNA-directed therapeutics. Full article

(This article belongs to the Special Issue Recent Advances in Fragment-Based Drug Discovery)

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19 pages, 1292 KB

Open AccessArticle

Biodegradation of Cyanide-Based Compounds by Rhodanese Produced from Kocuria rhizophila Under Submerged Fermentation and Its Role in Environmental Detoxification

by Nada Z. Mahdi, Suhair Sh. Al-Siraj, Nehad A. Taher, Muneefah Abdullah Alenezi, Khyreyah J. Alfifi, Fauzeya Mateq Albalwe, Hanan Khalaf Anazi, Siham M. AL-Balawi, Mahmoud Galal, Maha F. Lotfy and Eman M. Sharaf

Molecules 2026, 31(6), 915; https://doi.org/10.3390/molecules31060915 - 10 Mar 2026

Abstract

Widespread release of cyanide from industrial activities represents a significant environmental challenge due to its acute toxicity and adverse effects on biological systems. In response to this concern, this study focused on the production of rhodanese from Kocuria rhizophila under submerged fermentation conditions [...] Read more.

Widespread release of cyanide from industrial activities represents a significant environmental challenge due to its acute toxicity and adverse effects on biological systems. In response to this concern, this study focused on the production of rhodanese from Kocuria rhizophila under submerged fermentation conditions and the assessment of its relevance for cyanide detoxification applications. A soil-derived Gram-positive bacterium was isolated and identified as Kocuria rhizophila based on morphological traits, biochemical profile-based VITEK 2 analysis, and 16S rRNA gene sequencing. Preliminary screening confirmed rhodanese production with an activity of 0.968 RU/mL. Under cyanide-induced submerged fermentation, enzyme production followed a growth-associated pattern and reached maximal activity at 40 h under optimized conditions (35 °C, pH 8.0). Partial purification using sequential precipitation and chromatographic steps enhanced enzyme purity, and SDS–PAGE analysis of the final fraction revealed protein bands at approximately 40, 140, and 260 kDa. Biochemical characterization showed Km values of 33.9 mM for KCN and 19.7 mM for sodium thiosulfate, with a Vmax of ~5.6 µmol min⁻¹ mL⁻¹ for KCN and optimal activity at pH 7–8 and 35 °C. Functional assays demonstrated efficient cyanide detoxification, achieving >85% conversion of KCN, ~92% of NaCN, and 65–77% of Ca (CN)₂ within 60 min in vitro. Collectively, these findings demonstrate that Kocuria rhizophila represents a promising microbial source of rhodanese with efficient cyanide-detoxifying activity, highlighting its potential for biotechnological and environmental remediation applications. Full article

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71 pages, 3081 KB

Open AccessReview

Tides of Promise: Sponge-Derived Marine Natural Products in Southeast Asia

by Lik Tong Tan, Clarissa Widyantoro and Novriyandi Hanif

Molecules 2026, 31(5), 914; https://doi.org/10.3390/molecules31050914 - 9 Mar 2026

Abstract

Southeast Asia (SEA) harbors one of the world’s richest reservoirs of marine biodiversity, offering immense potential for natural product discovery. This review presents a comprehensive survey of sponge-derived marine natural products (MNPs), with notable activity, reported from SEA over the past two decades, [...] Read more.

Southeast Asia (SEA) harbors one of the world’s richest reservoirs of marine biodiversity, offering immense potential for natural product discovery. This review presents a comprehensive survey of sponge-derived marine natural products (MNPs), with notable activity, reported from SEA over the past two decades, highlighting their chemical diversity, biological activities and regional research trends. Analysis of the past two decades of MNPs data reveals that sponges (Phylum Porifera) remain the dominant source of new MNPs, representing nearly half of all discoveries in the region. Indonesia, Vietnam, and Thailand are leading contributors, with Indonesia exhibiting the highest productivity but limited local research leadership. The South China Sea and Indonesian archipelagos emerge as biodiversity and bioprospecting hotspots, yet large areas remain underexplored. Bioactive metabolites isolated from SEA sponges demonstrate potent anticancer, antimicrobial, anti-inflammatory, antiviral and enzyme-inhibitory properties, underscoring their value for pharmaceutical innovation. Despite this promise, uneven research capacity, infrastructure gaps and environmental degradation constrain sustainable exploitation. By consolidating recent advances in lead compound development and identifying key taxonomic as well as geographic priorities, this review strengthens the scientific foundation for marine drug discovery in SEA and supports integration of bioprospecting with regional Blue Economy and biodiversity conservation agendas and programs. Full article

(This article belongs to the Section Natural Products Chemistry)

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22 pages, 1619 KB

Open AccessArticle

Impact of Olive Variety and Cultivation Region on the Chemical Composition and Sensory Attributes of Turkish Olive Oils

by Didar Sevim, Oya Köseoğlu, Lacrimioara Senila, Anca Becze, Marin Senila, Pınar Kadiroğlu Kelebek and Ayla Mumcu

Molecules 2026, 31(5), 913; https://doi.org/10.3390/molecules31050913 - 9 Mar 2026

Abstract

Extra virgin olive oils obtained from the Ayvalık, Memecik, Gemlik, Çekişte, and Sarı Ulak Turkish cultivars were evaluated to determine their chemical composition, quality classification, authenticity indicators, and sensory characteristics. Standard quality parameters, including free fatty acidity, peroxide value, and ultraviolet absorbance (K232, [...] Read more.

Extra virgin olive oils obtained from the Ayvalık, Memecik, Gemlik, Çekişte, and Sarı Ulak Turkish cultivars were evaluated to determine their chemical composition, quality classification, authenticity indicators, and sensory characteristics. Standard quality parameters, including free fatty acidity, peroxide value, and ultraviolet absorbance (K232, K270), were analyzed in accordance with International Olive Council (IOC) regulations. The majority of the samples met the criteria for extra virgin olive oil. The oleic acid content varied by variety and region, with Ayvalık and Memecik showing notably high levels. Sterol profile analyses revealed distinctive chemical markers that indicate authenticity and quality. Sensory analysis results showed that regional differences had a significant impact on aroma, taste, and overall acceptability. Oils from Ayvalık and Memecik received high scores for positive sensory attributes such as fruitiness, bitterness, and pungency. The results show that the chemical and sensory qualities of olive oil are directly influenced by both genetic diversity and growing conditions, which underscores the importance of conserving local varieties and promoting regional production methods. Full article

(This article belongs to the Special Issue Chemical Composition, Antiradical Potential and Sensory Qualities of Lesser-Known Fruits)

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18 pages, 455 KB

Open AccessArticle

Effect of Textured Plant Protein Granulation and Presence of Dried Plant Ingredients on Physicochemical Properties of Soy-Based Burger

by Klaudia Kołodziejczak, Klara Żbik, Iwona Wojtasik-Kalinowska, Anna Onopiuk and Andrzej Poltorak

Molecules 2026, 31(5), 912; https://doi.org/10.3390/molecules31050912 - 9 Mar 2026

Abstract

Meat analogues have gained high interest from consumers, food producers and the scientific community due to their potential to be a sustainable alternative to traditional meat products. This study investigated the effect of textured soy protein granulation on the structural and biochemical properties [...] Read more.

Meat analogues have gained high interest from consumers, food producers and the scientific community due to their potential to be a sustainable alternative to traditional meat products. This study investigated the effect of textured soy protein granulation on the structural and biochemical properties of plant-based burgers. Additionally, the incorporation of bioactive plant ingredients, including pomegranate, cardamom, juniper, and carrot powders, was examined for their influence on antioxidant capacity and lipid oxidation during storage. The results demonstrated that larger protein granulation (4–6 mm) enhanced burger hardness and springiness and increased cooking-induced weight loss. The addition of plant-derived bioactive ingredients improved oxidative stability and functional properties, indicating their potential role in extending shelf life and improving product quality. This research provides important knowledge on the role of product formulation and the use of bioactive ingredients in the development of high-quality meat analogues with acceptable physic-chemical properties. Full article

(This article belongs to the Special Issue Nutritional and Bioactive Components of Edible Parts of Medicinal Plants)

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15 pages, 4563 KB

Open AccessArticle

Insights into the Enhanced Tetracycline Adsorption by Two-Dimensional Cu-Based Metal–Organic Framework

by Linteng Wang, Shi Wang, Yonglong Pang, Liyuan Guo, Jiming Huang, Ping Xue and Lingjun Kong

Molecules 2026, 31(5), 911; https://doi.org/10.3390/molecules31050911 - 9 Mar 2026

Abstract

Accumulation of tetracycline (TC) in aquatic environments poses a significant threat to human health and ecosystems, driving the need for efficient removal technologies. Two-dimensional metal–organic frameworks (2D MOFs) are promising adsorbents due to their tunable structures and abundant active sites. In this work, [...] Read more.

Accumulation of tetracycline (TC) in aquatic environments poses a significant threat to human health and ecosystems, driving the need for efficient removal technologies. Two-dimensional metal–organic frameworks (2D MOFs) are promising adsorbents due to their tunable structures and abundant active sites. In this work, three 2D MOFs, M₃(HHTP)₂ (M = Cu, Ni, Co), were synthesized via a solvothermal method. Among them, Cu₃(HHTP)₂ exhibited superior TC adsorption with a maximum capacity of 302.84 mg/g. The adsorption process, best described by the Langmuir isotherm and pseudo-second-order kinetic models, indicates chemisorption. Mechanistic investigations reveal that the high-activity coordination sites formed by Cu²⁺ due to Jahn–Teller distortion enable strong coordination with TC. This is identified as the key factor governing the differential adsorption performance among the three MOFs. Simultaneously, the surface functional groups facilitate hydrogen bonding, and the advantageous pore structure of the material itself, together forming a synergistic adsorption. This work not only elucidates the microscopic mechanism behind the efficient adsorption of TC by Cu₃(HHTP)₂ but also, through comparative analysis of isostructural MOFs, confirms the decisive role of metal center electronic structure in modulating the adsorption behavior of 2D MOFs. The insights gained from this study may serve as a reference for the design of 2D high-performance adsorbents. Full article

(This article belongs to the Section Materials Chemistry)

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25 pages, 3028 KB

Open AccessArticle

Green Synthesis of Au-Pd Bimetallic Nanoparticles Using Aspalathin and Their Toxicity Study

by Naledi D. Seatle, Akeem O. Akinfenwa, Keenau M. Pearce, Idowu J. Sagbo, Mongi Benjeddou and Ahmed A. Hussein

Molecules 2026, 31(5), 910; https://doi.org/10.3390/molecules31050910 - 9 Mar 2026

Abstract

Bimetallic nanoparticles have garnered significant attention in scientific literature due to their diverse applications and unique properties. Concurrently, green synthesis methodologies have emerged as environmentally friendly alternatives, reducing the ecological footprint of nanoparticle production. In this study, the efficient synthesis of Au-Pd bimetallic [...] Read more.

Bimetallic nanoparticles have garnered significant attention in scientific literature due to their diverse applications and unique properties. Concurrently, green synthesis methodologies have emerged as environmentally friendly alternatives, reducing the ecological footprint of nanoparticle production. In this study, the efficient synthesis of Au-Pd bimetallic nanoparticles is presented, utilizing Aspalathus linearis (Burm.f.) R. Dahlgren, commonly known as green rooibos (GR), and its pure bioactive compound, Aspalathin (ASP). Integrating ASP as a pure compound into the green synthesis process offers precise control over nanoparticle characteristics, including size, morphology, and composition. Interestingly, the total extract forms an Au-Pd nanoparticle alloy, while aspalathin forms core–shell nanoparticles. Furthermore, cytotoxicity testing was carried out on selected cell lines to assess their impact on cell viability. The cytotoxicity test on cell lines and cellular uptake analysis demonstrated that none of the tested samples exhibited significant cytotoxic effects. ASP-conjugated bimetallic increased the uptake of the NPs by the cells more than the total extract. The results demonstrated that the Au-Pd bimetallic nanoparticles hold promise for biomedical applications, owing to their enhanced biocompatibility and tailored properties. Full article

(This article belongs to the Special Issue Gold Nanoparticles in Biomedical Applications: Recent Advances and Future Perspectives)

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29 pages, 2023 KB

Open AccessReview

Unlocking the Potential of Macroalgae: Innovative Pretreatment Strategies for Efficient Biorefinery

by Xiucheng Gu and Ying Zhou

Molecules 2026, 31(5), 909; https://doi.org/10.3390/molecules31050909 - 9 Mar 2026

Abstract

Macroalgae represent a promising third-generation feedstock for biorefinery due to their high biomass productivity and non-reliance on arable land. However, their complex cell wall structure poses a significant barrier to efficient bioconversion. This review integrates current pretreatment methods, including physical, chemical, biological, and [...] Read more.

Macroalgae represent a promising third-generation feedstock for biorefinery due to their high biomass productivity and non-reliance on arable land. However, their complex cell wall structure poses a significant barrier to efficient bioconversion. This review integrates current pretreatment methods, including physical, chemical, biological, and combined approaches, with a focus on their mechanisms, effectiveness, and limitations. Furthermore, it explores the conversion of pretreated macroalgal biomass into bioenergy and biochemicals, such as bioethanol, organic acid and polyhydroxyalkanoate, via microbial fermentation. The review also examines the application of genetic editing tools (e.g., CRISPR-Cas systems) for the targeted modification of macroalgae to improve their inherent characteristics for biorefinery, such as reducing biomass recalcitrance or increasing the content of target carbohydrates. Finally, future perspectives on technological innovations and integrated industrial chains of macroalgal biorefinery are discussed. This review serves as a systematic reference for deepening the understanding of macroalgal cell wall deconstruction processes and supports the development of efficient and environmentally benign pretreatment strategies to advance macroalgal biorefinery toward industrialization. Full article

(This article belongs to the Special Issue Design of Chemically Recyclable Polymers in Sustainable Chemistry: A Minimalist Perspective)

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20 pages, 1838 KB

Open AccessArticle

Iron(II) and Manganese(II) Complexes with N4Py as Dioxygen Activators for α-Pinene Oxidation in Acetonitrile

by Katarzyna Rydel-Ciszek and Andrzej Sobkowiak

Molecules 2026, 31(5), 908; https://doi.org/10.3390/molecules31050908 - 9 Mar 2026

Abstract

Iron(II) and manganese(II) complexes with N4Py [N4Py—N,N-bis(2-pyridylmethyl)-N-(bis-2-pyridylmethyl)amine] have been found to activate O₂ for the oxidation of α-pinene in acetonitrile. For example, for 1 M α-pinene, 0.5 mM [(N4Py)Fe^II]²⁺, and dioxygen as [...] Read more.

Iron(II) and manganese(II) complexes with N4Py [N4Py—N,N-bis(2-pyridylmethyl)-N-(bis-2-pyridylmethyl)amine] have been found to activate O₂ for the oxidation of α-pinene in acetonitrile. For example, for 1 M α-pinene, 0.5 mM [(N4Py)Fe^II]²⁺, and dioxygen as an oxidant, 90 mM α-pinene epoxide, 48 mM verbenol, and 50 mM verbenone have been formed, which, taking into account the concentrations of the minor products (myrtenol and myrtenal), gives a turnover number approximately equal to 400. Based on the amounts of products formed, the conversion of α-pinene is approximately 20% and 18% for iron and manganese catalysts, respectively. Although the manganese catalyst is somewhat less effective than the iron catalyst, the selectivity of the products is similar for both catalysts. Replacement of dioxygen with air as the oxidant causes the reaction yield to be lower. The proposed mechanism assumes the formation of a metal(IV)-oxo complex [(N4Py)M^IV=O]²⁺, M–Fe or Mn, during the simultaneous combination of a catalyst, O₂, and substrate, and its subsequent reactions toward the observed products. Full article

(This article belongs to the Special Issue Advances in Coordination Chemistry, 3rd Edition)

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22 pages, 2146 KB

Open AccessArticle

Combining Temozolomide with a Selective CK2 Inhibitor Results in Anti-Tumour Effects in Glioblastoma Cell Lines

by Anne S. Boewe, Hendrik Rumler, Dagmar Aichele, Thomas Bödeker, Matthias W. Laschke, Emmanuel Ampofo, Joachim Jose and Claudia Götz

Molecules 2026, 31(5), 907; https://doi.org/10.3390/molecules31050907 - 9 Mar 2026

Abstract

Glioblastoma is one of the most aggressive tumours with a poor prognosis and a modest survival rate after diagnosis. Several trials for a more targeted and effective treatment are in progress. Protein kinase CK2 is upregulated in glioblastoma and creates a favourable environment [...] Read more.

Glioblastoma is one of the most aggressive tumours with a poor prognosis and a modest survival rate after diagnosis. Several trials for a more targeted and effective treatment are in progress. Protein kinase CK2 is upregulated in glioblastoma and creates a favourable environment for cell proliferation by supporting several survival pathways. Inhibitors of CK2 kinase activity were shown to restrict growth rate or to induce apoptosis in different cell culture and animal models. Recently, we described the selective CK2 inhibitor 6,7-dichloro-1,4-dihydro-8-hydroxy-4(4 methylphenylamino)methylen]dibenzo [b,d]furan 3(2H)-one (TF). In this study, we found that TF effectively reduces the proliferation of A1207 glioblastoma cells with an EC₅₀ value of 13.7 µM, which is equal to the EC₅₀ value of CX-4945, which was the first CK2 inhibitor in clinical phase II trials (13.9 µM). We investigated the effect of TF and temozolomide (TMZ) as a single or combination treatment in two glioblastoma cell lines, A1207 and U87. The treatment was carried out over 48 or 72 h, and, subsequently, the biological effects were evaluated. The proliferation of both cell lines was significantly impaired by the application of the drugs, and combination treatment with TF and TMZ proved superior to the individual treatments. Not only proliferation, as determined by cell confluence assays and BrdU incorporation, but also viability in terms of metabolic activity and cytotoxicity were affected by the treatment. The decrease in proliferation and viability is partly due to the induction of apoptosis, with both cell lines differing in terms of the pattern of apoptotic caspases. Taken together, TF in combination with TMZ may be a promising candidate for the treatment of glioblastoma in the future. Full article

(This article belongs to the Section Medicinal Chemistry)

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22 pages, 4892 KB

Open AccessArticle

GC-MS Analysis and Antioxidant Evaluation of Essential Oils from Chimonanthus salicifolius and Chimonanthus nitens

by Ailan Pan, Xingfan Gu, Miao Zheng, Longqing Chen and Nan Yang

Molecules 2026, 31(5), 906; https://doi.org/10.3390/molecules31050906 - 9 Mar 2026

Abstract

Chimonanthus salicifolius and Chimonanthus nitens are widely used in the food and pharmaceutical industries. Traditionally, their stems and leaves have been consumed as herbal tea substitutes in folk practices, possessing both medicinal and edible values. They represent typical dual-purpose plants for both medicinal [...] Read more.

Chimonanthus salicifolius and Chimonanthus nitens are widely used in the food and pharmaceutical industries. Traditionally, their stems and leaves have been consumed as herbal tea substitutes in folk practices, possessing both medicinal and edible values. They represent typical dual-purpose plants for both medicinal and tea applications and are distinctive ethnic She medicinal resources. This study used the flowers, stems, and leaves of C. salicifolius and C. nitens as materials to analyze the chemical components of six essential oils and evaluate their antioxidant and antibacterial activities. We extracted their essential oils through steam distillation, followed by an analysis of their volatile chemical components using gas chromatography–mass spectrometry (GC-MS). Hydroxyl radical (•OH), 1,1-diphenyl-2-picryl hydrazyl (DPPH) and the ferric reducing ability of plasma (FRAP) were used to evaluate the antioxidant activities of the different essential oils. The results showed that the extraction rates of both Chimonanthus species followed the order of leaf > flower > stem. Among them, the essential oil extraction rate from the leaves of C. salicifolius was the highest (2.22%), followed by that from the leaves of C. nitens (0.84%). A total of 83 volatile components were identified from the six extracted essential oils, demonstrating significant compositional differences (p < 0.05). Eucalyptol is the main component and has the highest relative content in the essential oils of both plant leaves, with (54.65 ± 1.03%) in C. salicifolius and (52.28 ± 1.03%) in C. nitens. Antioxidant experiments revealed that the leaf essential oil exhibited the strongest •OH scavenging activity (IC50 = 39.47 ± 5.57 μL·mL⁻¹), while the stem of C. salicifolius showed the highest DPPH scavenging activity (IC50 = 20.78 ± 3.86), and the flower part demonstrated the best FRAP power. Additionally, a preliminary evaluation of the antibacterial activity of these two Chimonanthus leaf essential oils indicated that their minimum inhibitory concentration (MIC) against Staphylococcus aureus, Bacillus pumilus, and Bacillus subtilis was consistently 50 µL·mL⁻¹. This study systematically analyzed the chemical composition, antioxidant activity, and antibacterial activity of essential oils from different parts of C. salicifolius and C. nitens, revealing differences in yield, component composition, and biological activity between the two species. The findings provide scientific evidence for the development and application of essential oils from Chimonanthus plants. Full article

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5 pages, 256 KB

Open AccessEditorial

Molecules Editorial: 30 Years of Molecules—An Editor’s Experiences and Visions for the Future

by Thomas J. Schmidt

Molecules 2026, 31(5), 905; https://doi.org/10.3390/molecules31050905 - 9 Mar 2026

Abstract

Dear readers, authors, reviewers, editors, coworkers and staff of Molecules! [...] Full article

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11 pages, 1862 KB

Open AccessArticle

Computational Insights into the Relationship Between Solution Concentration and Adsorption Energy

by Wangyan Lv, Wenjie Zhou, Ming Nie, Chenyang Yao, Zhong’ao Wang, Yongchun Liang, Songyu Xie and Chaofang Dong

Molecules 2026, 31(5), 904; https://doi.org/10.3390/molecules31050904 - 9 Mar 2026

Abstract

The electrochemical interaction between aggressive ions and metals plays a key role in corrosion failure processes. The Langmuir adsorption isotherm equation was employed to reveal that surface coverage remains largely unchanged at higher concentrations, with the concentration effect partially mediated by the dielectric [...] Read more.

The electrochemical interaction between aggressive ions and metals plays a key role in corrosion failure processes. The Langmuir adsorption isotherm equation was employed to reveal that surface coverage remains largely unchanged at higher concentrations, with the concentration effect partially mediated by the dielectric properties of the solution. The work function and adsorption energy of two typical corrosive elements, Cl and S, adsorbed on the surfaces of two metals (Al and Cu) were systematically calculated. By adjusting solubilization parameters in different implicit solvent models, variations in dielectric properties at similar surface coverage under different concentrations were simulated. It was observed that as the solution concentration increased, the electrostatic shielding effect of the surface solution was enhanced, while the changes in adsorption energy were not statistically significant. However, the work function was found to increase by approximately 20–90 meV with increasing concentration, with the magnitude of this increase dependent on the metal type and surface orientation. This enhancement further strengthened the adsorbate–substrate interaction, thereby influencing the electrochemical reaction kinetics of the surface material. Full article

(This article belongs to the Section Materials Chemistry)

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14 pages, 1746 KB

Open AccessArticle

Bioconversion of Organosolv Lignin by Rumen Bacterium: Isolation, Characterization and Metabolic Profiling

by Jéssica Pinheiro Silva, Jailson Novaes de Miranda, Sofia Chacon Prates Uchoa, Artur Carvalho Stranz, Rosália Loriano de Santana, Pedro Ricardo Vieira Hamann, Alonso R. Poma Ticona, Thomas Christopher Rhys Williams, Fernando Araripe Gonçalves Torres, Roberto Castellanos and Eliane Ferreira Noronha

Molecules 2026, 31(5), 903; https://doi.org/10.3390/molecules31050903 - 9 Mar 2026

Abstract

Residual lignin generated by pulp, paper, and biorefining industries is commonly burned for energy, despite its potential as a renewable source of aromatic compounds. Studies focusing on microbial lignin degradation contribute to lignin valorization and represent a sustainable strategy to enhance biomass circularity. [...] Read more.

Residual lignin generated by pulp, paper, and biorefining industries is commonly burned for energy, despite its potential as a renewable source of aromatic compounds. Studies focusing on microbial lignin degradation contribute to lignin valorization and represent a sustainable strategy to enhance biomass circularity. Here, we report the isolation of Klebsiella sp. IL2_9 from a ruminal consortium and demonstrate its ability to degrade and metabolize organosolv lignin. After 24 h of cultivation, the strain removed 22% of the initial lignin content. FTIR analysis revealed alterations in functional groups associated with guaiacyl and syringyl units, indicating structural modification of the polymer. GC–MS analyses further showed the consumption of lignin-derived aromatics, including vanillin, 2-aminobenzoic acid, and 4-hydroxybenzoic acid, along with the formation of vanillyl alcohol and phenyllactic acid derivatives. Overall, these findings highlight the potential of Klebsiella sp. IL2_9 as a promising biotechnological candidate for lignin valorization under anaerobic conditions. Full article

(This article belongs to the Special Issue Green Chemistry Strategies for Biomass Valorization)

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17 pages, 3763 KB

Open AccessArticle

Boosting Photocatalytic CO₂ Cycloaddition via Dual-Active Site Coordination over Amino-Functionalized UiO-66(Zr)

by Yajing Lv, Haohao Yan, Wenhui Ye, Lin Ye, Jinmei Chen, Yutong Lin, Shuying Zhu, Dengrong Sun, Xiyao Liu and Ruowen Liang

Molecules 2026, 31(5), 902; https://doi.org/10.3390/molecules31050902 - 9 Mar 2026

Abstract

CO₂ cycloaddition with epoxides offers a sustainable route for CO₂ utilization, yet the simultaneous activation of both substrates remains challenging. Herein, using UiO-66(Zr)-NH₂ (denoted as UZN) as a model system, we illustrate that dual-active sites consisting of unsaturated Zr⁴⁺ [...] Read more.

CO₂ cycloaddition with epoxides offers a sustainable route for CO₂ utilization, yet the simultaneous activation of both substrates remains challenging. Herein, using UiO-66(Zr)-NH₂ (denoted as UZN) as a model system, we illustrate that dual-active sites consisting of unsaturated Zr⁴⁺ centers and amine groups can efficiently accelerate CO₂ fixation with epoxides under visible light. The unique ensemble in UZN optimizes light harvesting, promotes charge carrier separation, and enriches bifunctional active sites for efficient adsorption and activation of epoxides and CO₂. Consequently, UZN exhibits significantly improved CO₂-epoxide cycloaddition performance compared to UiO-66(Zr)-H (denoted as UZH), achieving a PC yield of 99.5%, with a production rate of 9.97 mmol·g⁻¹·h⁻¹. This work establishes a clear coordination–photocatalytic synergy in MOF-based systems and provides fundamental insights and a generalizable strategy for designing advanced catalysts for CO₂ transformation. Full article

(This article belongs to the Section Photochemistry)

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