Molecules

19 pages, 2066 KiB

Open AccessArticle

Diorganotin(IV) Complexes of Organoselenolato Ligands with Pyrazole Moieties—Synthesis, Structure and Properties

by Melinda Tamas, Roxana A. Butuza, Monica Dan and Anca Silvestru

Molecules 2025, 30(7), 1648; https://doi.org/10.3390/molecules30071648 - 7 Apr 2025

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Diorganotin(IV) compounds of types RR′Sn(SeCH₂CH₂pz)₂ [R = R′ = ⁿBu (2), Ph (3); R = 2-(Me₂NCH₂)C₆H₄, R′ = Me (4), ⁿBu ( [...] Read more.

Diorganotin(IV) compounds of types RR′Sn(SeCH₂CH₂pz)₂ [R = R′ = ⁿBu (2), Ph (3); R = 2-(Me₂NCH₂)C₆H₄, R′ = Me (4), ⁿBu (5), Ph (6)], and RR′SnX(SeCH₂CH₂pz) [R = 2-(Me₂NCH₂)C₆H₄, R′ = ⁿBu, X = Cl (7), R′ = Me, X = SCN (9)], as well as [2-(Me₂NCH₂)C₆H₄](Me)Sn(NCS)₂ (8), and the tin(II) Sn(SeCH₂CH₂pz)₂ (10) (pz = pyrazole), were prepared by salt metathesis reactions between the appropriate diorganotin(IV) dichloride or dipseudohalide and Na[SeCH₂CH₂pz], with the latter freshly prepared from (pzCH₂CH₂)₂Se₂ (1). The solution behaviour of these compounds was investigated by multinuclear NMR (¹H, ¹³C, ⁷⁷Se, ¹¹⁹Sn), and the NMR spectra showed the existence of the Se–Sn bonds in solution. Compounds 4 and 5 showed decomposition in a solution of chlorinated solvents with the formation of selenium bridged dimeric species of type {[2-(Me₂NCH₂)C₆H₄](R’)Se}₂ [R′ = Me (4-a), ⁿBu (5-a)], as the single-crystal X-ray diffraction studies revealed, in contrast with compound 9, for which a monomeric structure was observed with the desired composition. The solid state structures of 4-a, 5-a, 8, and 9 revealed N→Sn intramolecular coordination of the nitrogen atom in the pendant CH₂NMe₂ arm. The NMR spectra suggested such a coordination at room temperature only for compound 7. Full article

(This article belongs to the Special Issue Recent Advances in the Synthesis, Functionalization and Applications of Pyrazole-Type Compounds III)

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17 pages, 6354 KiB

Open AccessArticle

Developing a Multi-Method Approach for Understanding Cellular Uptake and Biological Response: Investigating Co-Exposure of Macrophage-like Differentiated THP-1 Cells to Al₂O₃ and CeO₂ Nanoparticles

by Yves Uwe Hachenberger, Benjamin Christoph Krause, Fabian Lukas Kriegel, Philipp Reichardt, Jutta Tentschert, Harald Jungnickel, Frank Stefan Bierkandt, Peter Laux, Ulrich Panne and Andreas Luch

Molecules 2025, 30(7), 1647; https://doi.org/10.3390/molecules30071647 - 7 Apr 2025

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Abstract

The use of different nanoparticles (NPs) is increasing in a wide variety of everyday products. Nevertheless, most studies concerning NP risk assessment have evaluated exposure scenarios involving a single kind of NP. A stepwise study distinguishing between the effects resulting from exposure to [...] Read more.

The use of different nanoparticles (NPs) is increasing in a wide variety of everyday products. Nevertheless, most studies concerning NP risk assessment have evaluated exposure scenarios involving a single kind of NP. A stepwise study distinguishing between the effects resulting from exposure to one kind of NP and those resulting from different co-exposure scenarios to

{Al}_{2} O_{3}

and

{CeO}_{2}

NPs at concentrations below acute toxicity was conducted with different analytical techniques. As a starting point, WST-1 viability assays were performed to assess whether the chosen exposure concentrations resulted in any acute loss of viability, which would hamper further insight into the cellular response to NP exposure. Then, data on NP dissolution and uptake were obtained via single-particle inductively coupled plasma–mass spectrometry (spICP-MS) and microwave-assisted ICP-MS. Additionally, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was performed to check for differences in the biological response to the exposure scenarios at the single-cell level. It was found that the proposed combined techniques provide insight into changes in biological responses as well as cellular metal contents among the exposure scenarios. In this work, a comprehensive tiered analytical strategy for evaluating the biological responses to challenging exposure scenarios is provided. The results highlight the necessity of selecting situations more closely resembling real life—including concentrations below acute toxicity and potential interactions due to multiple NPs—when estimating potential health risks. These findings thus provide a foundation and an incentive for further research into the complex processes leading to the observed effects. Full article

(This article belongs to the Section Analytical Chemistry)

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14 pages, 5785 KiB

Open AccessArticle

Optimization of Squalene Production by Pseudozyma sp. P4-22

by Chen Huang, Xiaojin Song, Jingyi Li, Qiu Cui, Pengfei Gu and Yingang Feng

Molecules 2025, 30(7), 1646; https://doi.org/10.3390/molecules30071646 - 7 Apr 2025

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Abstract

Squalene is an important bioactive substance widely used in the food, pharmaceutical, and cosmetic industries. Microbial production of squalene has gained prominence in recent years due to its sustainability, safety, and environmental friendliness. In this study, a mutant strain, Pseudozyma sp. P4-22, with [...] Read more.

Squalene is an important bioactive substance widely used in the food, pharmaceutical, and cosmetic industries. Microbial production of squalene has gained prominence in recent years due to its sustainability, safety, and environmental friendliness. In this study, a mutant strain, Pseudozyma sp. P4-22, with enhanced squalene-producing ability, was obtained through atmospheric and room temperature plasma mutagenesis of the previously screened squalene-producing yeast Pseudozyma sp. SD301. The P4-22 strain demonstrated the ability to produce squalene using various carbon and nitrogen sources. We optimized the culture conditions by employing cost-effective corn steep liquor as the nitrogen source, and the optimal pH and sea salt concentration of the medium were determined to be 5.5 and 5 g/L, respectively. Under optimal cultivation conditions, the biomass and squalene production reached 64.42 g/L and 2.06 g/L, respectively, in a 5 L fed-batch fermentation. This study highlights the potential of Pseudozyma sp. P4-22 as a promising strain for commercial-scale production of squalene. Full article

(This article belongs to the Special Issue Biomanufacturing of Natural Bioactive Compounds)

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22 pages, 3356 KiB

Open AccessArticle

Spontaneous Reaction of Oleacein and Oleocanthal with Primary Amines: A Biochemical Perspective

by Daniel Di Risola, Davide Laurenti, Francesca Ferraro, Alessia Ciogli, Simone Manetto, Yuri Gazzilli, Rodolfo Federico, Antonio Francioso, Luciana Mosca and Roberto Mattioli

Molecules 2025, 30(7), 1645; https://doi.org/10.3390/molecules30071645 - 7 Apr 2025

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Abstract

Oleacein (Olea) and Oleocanthal (Oleo) are two phenolic compounds found in olive oil. Cell and animal studies have shown these two compounds can modulate inflammation, cancer, and neurodegenerative diseases. Unfortunately, the study of the pharmacokinetics of these two compounds appears difficult due to [...] Read more.

Oleacein (Olea) and Oleocanthal (Oleo) are two phenolic compounds found in olive oil. Cell and animal studies have shown these two compounds can modulate inflammation, cancer, and neurodegenerative diseases. Unfortunately, the study of the pharmacokinetics of these two compounds appears difficult due to their high reactivity with primary amines. Indeed, the presence of primary amines in culture media and biological fluids raises the question as to whether the observed biological effects are attributable to the parent compounds or to their amine derivatives. In the present work, we investigated the adduct formation between Olea or Oleo and tris(hydroxymethyl)aminomethane (Tris), a well-known primary amine used primarily as a buffer system, showing that the reaction kinetics were extremely rapid. In addition, we assessed whether the newly formed Tris adducts, i.e., Olea-Tris and Oleo-Tris, retained their antioxidant capacity by means of the ABTS and DPPH radical scavenging assays, showing that their activity was partially maintained. Finally, we evaluated the anti-inflammatory activity of these adducts on murine BV-2 microglial cells stimulated with lipopolysaccharide (LPS) and kept in an amine-free culture medium, showing how the biological response varied as the compound was degraded. Taken together, these data demonstrate that the biological effects reported in the literature are mainly due to the amino-derivatives of Olea and Oleo rather than the polyphenols derived from their breakdown (tyrosol and hydroxytyrosol). Full article

(This article belongs to the Section Natural Products Chemistry)

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14 pages, 5556 KiB

Open AccessArticle

Lipidated DAPEG Polymers as a Non-Toxic Transfection Agent—Influence of Fatty Acid Side Chain on Transfection Efficacy

by Wiktoria Mallek, Anita Romanowska, Wiktoria Machowicz, Agnieszka Piwkowska, Adam Lesner and Magdalena Wysocka

Molecules 2025, 30(7), 1644; https://doi.org/10.3390/molecules30071644 (registering DOI) - 7 Apr 2025

Viewed by 56

Abstract

This study describes the synthesis, interaction with DNA, and transfection efficacy of eight lipidated compounds based on a recently published non-lipidated parent molecule, an octamer of 2,3-l-Dap, carrying the guanidine group on its side chain. The compounds obtained were found to [...] Read more.

This study describes the synthesis, interaction with DNA, and transfection efficacy of eight lipidated compounds based on a recently published non-lipidated parent molecule, an octamer of 2,3-l-Dap, carrying the guanidine group on its side chain. The compounds obtained were found to be non-toxic up to 5 µM and efficient DNA binders and showed greater transfection efficiency than the parent compound, with two leading molecules containing acetic and decanoic moieties. DLS experiments indicated two groups of interaction with DNA. One group modified by short-chain lipids (up to eight carbon atoms in the main chain) forms large structures due to the aggregation of multiple nucleic acids. The second group (from twelve to sixteen carbon atoms) with dominant condensation creates smaller forms and is less effective in transporting DNA into the cells. Full article

(This article belongs to the Topic Advanced Biomaterials: Processing and Applications)

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12 pages, 2770 KiB

Open AccessArticle

Synthesis of 2-Amino-4, 5-Diarylthiazole Derivatives and Evaluation of Their Anti-Candida Albicans Activity

by Dongmei Gao, Lele Shi, Yuhang Huang, Yingmei Lv, Xuan Yang and Zhenting Du

Molecules 2025, 30(7), 1643; https://doi.org/10.3390/molecules30071643 (registering DOI) - 7 Apr 2025

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Abstract

The thiazole heterocycle is one of the most common moieties found in various drugs. Using 2-aminothiazole as the core structure, the amino group was functionalized with an amide. As a result, 30 trisubstituted 2-amino-4, 5-diarylthiazole derivatives were synthesized, with different substitutions introduced at [...] Read more.

The thiazole heterocycle is one of the most common moieties found in various drugs. Using 2-aminothiazole as the core structure, the amino group was functionalized with an amide. As a result, 30 trisubstituted 2-amino-4, 5-diarylthiazole derivatives were synthesized, with different substitutions introduced at the C2, C4, and C5 positions. The anti-Candida albicans biological activities of these synthetic compounds on five kinds of Candida albicans at different concentrations were detected by the microdilution method. In the first round, four derivatives of 2-amino-4, 5-diarylthiazole exhibited moderate anti-Candida albicans activity. Among them, 4a8 was chosen to be subjected to a demethylation process. Thus, 5a8 was synthesized successfully, giving anti-Candida albicans activity (MIC₈₀ = 9 μM) similar to that of a typical antifungal drug, fluconazole. To understand the mechanism of anti-Candida albicans, molecular docking of the most active 5a8 against four target proteins of anti-Candida albicans, such as glutamine-fructose-6-phosphoamidamitransferase (GFAT), protein kinase (Yck2), heat-shock protein 90 (Hsp90), and lanosterol 14a-demethylase (CYP51) was carried out. Our research will provide an experimental basis and theoretical guidance for the further design of a new aminothiazole-leading pharmaceutical molecule. Full article

(This article belongs to the Special Issue Synthesis of Bioactive Compounds: Volume II)

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22 pages, 4180 KiB

Open AccessArticle

Inhibition of Tyrosinase and Melanogenesis by Carboxylic Acids: Mechanistic Insights and Safety Evaluation

by Yu-Pei Chen, Mingyu Li, Zirong Liu, Jinxiong Wu, Fangfang Chen and Shudi Zhang

Molecules 2025, 30(7), 1642; https://doi.org/10.3390/molecules30071642 (registering DOI) - 7 Apr 2025

Viewed by 126

Abstract

It is well established that certain carboxylic acid compounds can effectively inhibit tyrosinase activity. This study investigated the mechanisms by which four carboxylic acid compounds—3-phenyllactic acid, lactic acid, L-pyroglutamic acid, and malic acid—inhibit tyrosinase and melanogenesis. IC₅₀ values for mushroom tyrosinase inhibition [...] Read more.

It is well established that certain carboxylic acid compounds can effectively inhibit tyrosinase activity. This study investigated the mechanisms by which four carboxylic acid compounds—3-phenyllactic acid, lactic acid, L-pyroglutamic acid, and malic acid—inhibit tyrosinase and melanogenesis. IC₅₀ values for mushroom tyrosinase inhibition ranged from 3.38 to 5.42 mM, with 3-phenyllactic acid (3.50 mM), lactic acid (5.42 mM), and malic acid (3.91 mM) exhibiting mixed-type inhibition, while L-pyroglutamic acid (3.38 mM) showed competitive inhibition, as determined by enzymatic kinetic analysis. Additionally, the acidification effects of lactic acid, L-pyroglutamic acid, and malic acid contributed to the reduction in tyrosinase activity. Furthermore, all four carboxylic acid compounds effectively inhibited DOPA auto-oxidation (IC₅₀ = 0.38–0.66 mM), ranking in potency as follows: malic acid (0.38 mM) > lactic acid (0.57 mM) > 3-phenyllactic acid (0.63 mM) > L-pyroglutamic acid (0.66 mM). These compounds also demonstrated a dose-dependent reduction in melanin production in B16-F10 cells. Proteomic analysis further revealed that these compounds not only inhibit key proteins involved in melanin synthesis, such as tyrosinase, tyrosinase-related protein 1, and tyrosinase-related protein 2, but also potentially modulate other genes associated with melanogenesis and metabolism, including Pmel, Slc45a2, Ctns, Oca2, and Bace2. Network toxicology analysis indicated that these four compounds exhibit a low risk of inducing dermatitis. These findings suggest that these compounds may indirectly regulate melanin-related pathways through multiple mechanisms, highlighting their potential for further applications in cosmetics and pharmaceuticals. Full article

(This article belongs to the Special Issue Advances in Chemistry of Cosmetics)

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16 pages, 4212 KiB

Open AccessArticle

Enhancing Photostability of Prochloraz via Designing Natural Acid-Derived Prochloraz-Based Ionic Liquids

by Zhiqiang Gao, Fengmao Liu, Qingrong Peng and Wenzhuo Wang

Molecules 2025, 30(7), 1641; https://doi.org/10.3390/molecules30071641 (registering DOI) - 7 Apr 2025

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Abstract

Converting pesticides into ionic liquids by designing counterions can modulate their physicochemical properties, thus improving their efficacy and environmental safety. In this study, eight prochloraz-based ionic liquids (PILs) were synthesized using natural organic acids, and their physicochemical properties, toxicity, antifungal activity, and efficacy [...] Read more.

Converting pesticides into ionic liquids by designing counterions can modulate their physicochemical properties, thus improving their efficacy and environmental safety. In this study, eight prochloraz-based ionic liquids (PILs) were synthesized using natural organic acids, and their physicochemical properties, toxicity, antifungal activity, and efficacy in postharvest mango preservation were evaluated. The results showed that the physicochemical properties of propiconazole, including water solubility, logK_ow, surface activity, and light stability, could be adjusted by selecting counterions with varying structures. These properties were correlated with toxicity to zebrafish embryos and antifungal activity against Colletotrichum gloeosporioides. Notably, except for the benzoate PIL, the photostability of the other seven PILs was enhanced under UV irradiation, with the cinnamate PIL exhibiting a half-life 2.28 times longer than prochloraz. Spectral analysis indicated that the anions influenced photostability by shielding or interacting with the cations. Furthermore, the three selected PILs improved pesticide deposition on the mango surface during preservation, and the salicylate PIL enhanced pesticide penetration into the fruit, potentially contributing to its therapeutic activity. In conclusion, the ionic liquid strategy offers an effective method to modify pesticide properties, improve photostability, reduce losses, and optimize pesticide formulation. Full article

(This article belongs to the Special Issue 10th Anniversary of Green Chemistry Section)

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25 pages, 8101 KiB

Open AccessArticle

Investigation of Anticancer Peptides Derived from Arca Species Using In Silico Analysis

by Jixu Wu, Xiuhua Zhang, Yuting Jin, Man Zhang, Rongmin Yu, Liyan Song, Fei Liu and Jianhua Zhu

Molecules 2025, 30(7), 1640; https://doi.org/10.3390/molecules30071640 (registering DOI) - 7 Apr 2025

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Abstract

This study employed an integrated in silico approach to identify and characterize anticancer peptides (ACPs) derived from Arca species. Using a comprehensive bioinformatics pipeline (BIOPEP, ToxinPred, ProtParam, ChemDraw, SwissTargetPrediction, and I-TASSER), we screened hydrolyzed bioactive peptides from Arca species, identifying seventeen novel peptide [...] Read more.

This study employed an integrated in silico approach to identify and characterize anticancer peptides (ACPs) derived from Arca species. Using a comprehensive bioinformatics pipeline (BIOPEP, ToxinPred, ProtParam, ChemDraw, SwissTargetPrediction, and I-TASSER), we screened hydrolyzed bioactive peptides from Arca species, identifying seventeen novel peptide candidates. Subsequent in vitro validation revealed three peptides (KW, WQIWYK, KGKWQIWYKSL) with significant anticancer activity, demonstrating both high biosafety and clinical potential. Our findings highlight Arca species proteins as a valuable source of therapeutic ACPs and establish bioinformatics as an efficient strategy for rapid discovery of bioactive peptides. This approach combines computational prediction with experimental validation, offering a robust framework for developing novel peptide-based therapeutics. Full article

(This article belongs to the Topic Advances in Separation Engineering)

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15 pages, 7066 KiB

Open AccessArticle

Highly Efficient Catalytic Oxidation of Glucose to Formic Acid over Mn-Mo Doped Carbon Nanotube

by Hongrui Guo, Fan Yang, Siwei Chen, Hejuan Wu, Jirui Yang and Feng Shen

Molecules 2025, 30(7), 1639; https://doi.org/10.3390/molecules30071639 - 7 Apr 2025

Viewed by 101

Abstract

The production of formic acid (FA) from lignocellulose and its derived sugars represents a pivotal upgrading reaction in biorefinery. This work prepared a Mn-Mo doped carbon nanotube composite catalyst for the catalytic oxidation of glucose into FA in an O₂ atmosphere, under [...] Read more.

The production of formic acid (FA) from lignocellulose and its derived sugars represents a pivotal upgrading reaction in biorefinery. This work prepared a Mn-Mo doped carbon nanotube composite catalyst for the catalytic oxidation of glucose into FA in an O₂ atmosphere, under extremely low Mn (3.27%) and Mo (0.40%) loading conditions, displaying a comparable performance with the traditional vanadium-based catalyst suffering from toxicity issues. It was confirmed that the doping of Mo led to the formation of MnMoO_X and increased the contents of low-valence Mn species (Mn²⁺ + Mn³⁺), lattice oxygen (O_latt), and surface adsorbed oxygen (O_ads) based on various characterization methods, such as XRD, XPS, TEM and ICP, which were beneficial to improve the catalytic performance. The maximum FA yield of 58.8% could be achieved over Mn₉Mo₁O_X@MWCNT after reaction for 6 h at 140 °C, which was far more than that obtained with undoped MnO_X@MWCNT (14.5%) at the identical conditions. Glyoxylic acid and arabinose were identified as two main intermediates, suggesting that the transformation of glucose into FA over Mn₉Mo₁O_X@MWCNT involved two different paths. This work proved that manganese-based catalyst was a green alternative for upgrading lignocellulose via catalytic oxidation. Full article

(This article belongs to the Special Issue Recent Advances in Porous Materials, 2nd Edition)

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18 pages, 7057 KiB

Open AccessArticle

Green Extraction of Volatile Terpenes from Artemisia annua L.

by Marta Mandić, Ivona Ivančić, Matija Cvetnić, Claudio Ferrante, Giustino Orlando and Sanda Vladimir-Knežević

Molecules 2025, 30(7), 1638; https://doi.org/10.3390/molecules30071638 - 7 Apr 2025

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Abstract

In the present study, the extraction of volatile terpenes from A. annua with supercritical CO₂ (sc-CO₂) was optimized by a full factorial design procedure and compared with conventional distillation. The influence of pressure (100–220 bar) and temperature (40–60 °C) on [...] Read more.

In the present study, the extraction of volatile terpenes from A. annua with supercritical CO₂ (sc-CO₂) was optimized by a full factorial design procedure and compared with conventional distillation. The influence of pressure (100–220 bar) and temperature (40–60 °C) on sc-CO₂ extraction was investigated to obtain extracts rich in the desired components while maintaining a high yield. Extraction yields (m/m) varied from 0.62% (130 bar/40 °C) to 1.92% (100 bar/60 °C). Monoterpenes were the most abundant constituents of the sc-CO₂ extracts, among which artemisia ketone (16.93–48.49%), camphor (3.29–18.44%) and 1,8-cineole (4.77–11.89%) dominated. Arteannuin B (3.98–10.03%) and β-selinene (1.05–7.42%) were the major sesquiterpenes. Differences were found between the terpene profiles of the sc-CO₂ extracts and the essential oils obtained by conventional hydrodistillation and steam distillation, as well as between the distilled essential oils. Our results demonstrate the optimal conditions for the rapid and effective supercritical extraction of certain monoterpenes and sesquiterpenes from A. annua, which have promising antimicrobial, antioxidant, antiviral, anti-inflammatory and antitumor properties. Full article

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17 pages, 5370 KiB

Open AccessArticle

Astaxanthin Mitigates ADHD Symptoms in Spontaneously Hypertensive Rats via Dopaminergic Modulation and Brain–Gut Axis Regulation

by Yueyang Leng, Ning Wu, Jing Wang, Lihua Geng, Yang Yue and Quanbin Zhang

Molecules 2025, 30(7), 1637; https://doi.org/10.3390/molecules30071637 - 7 Apr 2025

Viewed by 107

Abstract

Attention Deficit Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder that significantly impacts learning, daily functioning, and personal development. Astaxanthin (ASTA), a naturally occurring antioxidant, has garnered interest as a potential therapeutic agent for various diseases, particularly in mitigating oxidative stress. This study [...] Read more.

Attention Deficit Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder that significantly impacts learning, daily functioning, and personal development. Astaxanthin (ASTA), a naturally occurring antioxidant, has garnered interest as a potential therapeutic agent for various diseases, particularly in mitigating oxidative stress. This study explores a novel application of ASTA in the context of ADHD, aiming to investigate its therapeutic effects and underlying mechanisms. Spontaneously hypertensive rats (SHRs), widely used ADHD model animals, were treated with ASTA (50/100 mg/kg/day) for three weeks, 5 mg/kg/day atomoxetine (ATO) as the positive, and Wistar Kyoto (WKY) rats as control. Behavioral improvements were assessed using the open field test (OFT) and the Morris water maze (MWM). Biochemical analyses were conducted to evaluate changes in the levels of various neurotrophic factors, while histological examinations were performed to assess neuroprotective effects. Additionally, the role of ASTA in the brain–gut axis was investigated. The behavioral symptoms of hyperactivity, anxiety, and impaired spatial memory in ADHD animals were mitigated by ASTA. This improvement is primarily attributed to the restoration of neurotransmitter levels, particularly dopamine (DA), achieved through the modulation of several critical components within the dopamine system, including dopamine receptor 1 (DR1), dopamine transporter (DAT), tyrosine hydroxylase (TH), and synaptic-associated protein 25 (SNAP-25). Additionally, regulating the serotonin transporter (SERT) and glial cell-derived neurotrophic factor (GDNF) supports the recovery of serotonin levels and facilitates optimal brain development. Furthermore, cerebellar cells were protected, and the structure of the intestinal microbiota was regulated. ASTA can mitigate ADHD symptoms in SHR through the modulation of the dopaminergic system, multiple neurotransmitters, neurotrophic factors, and the neuro-intestinal environment, which establishes ASTA as a promising nutraceutical candidate for adjunctive therapy in pediatric ADHD. Full article

(This article belongs to the Special Issue Exploring Bioactive Organic Compounds for Drug Discovery, 2nd Edition)

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15 pages, 1528 KiB

Open AccessArticle

Anti-Cancer Stem Cell Properties of Square Planar Copper(II) Complexes with Vanillin Schiff Base Ligands

by Yihan Wang, Kuldip Singh, Chunxin Lu and Kogularamanan Suntharalingam

Molecules 2025, 30(7), 1636; https://doi.org/10.3390/molecules30071636 - 6 Apr 2025

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Abstract

Current breast cancer therapies are unable to positively impact the lives of a significant proportion of diagnosed patients (24% based on 10-year survival rate). Breast cancer relapse and metastasis, the leading cause of breast cancer-associated deaths, is linked to the existence of breast [...] Read more.

Current breast cancer therapies are unable to positively impact the lives of a significant proportion of diagnosed patients (24% based on 10-year survival rate). Breast cancer relapse and metastasis, the leading cause of breast cancer-associated deaths, is linked to the existence of breast cancer stem cells (CSCs). Redox-modulating metal complexes have been used to perturb the redox balance in breast CSCs and effect cell death. Here, we sought to expand this promising class of anti-breast CSC agents. Specifically, we report the synthesis, and anti-breast CSC properties of a series of copper(II) complexes bearing regioisomeric vanillin Schiff base ligands (1–4). X-ray crystallography studies show that the copper(II) complexes 1–4 adopt square planar geometries with the copper(II) centre coordinated to two vanillin Schiff base ligands. The most effective copper(II) complex within the series 4 displays low micromolar potency towards breast CSCs, up to 4.6-fold higher than salinomycin and cisplatin. Mechanistic studies indicate that copper(II) complex 4 elevates reactive oxygen species levels in breast CSCs, leading to activation of the JNK/p38 pathway and caspase-dependent apoptosis. Overall, this work expands the library of anti-breast CSC copper(II) complexes and provides insight into their mode of action. Full article

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

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13 pages, 652 KiB

Open AccessArticle

Optimization of Deep Eutectic Solvent-Based Ultrasound-Assisted Extraction of Bioactive Compounds from Maca Leaves Using the Taguchi Method

by Eun Ji Lee and Kyung Young Yoon

Molecules 2025, 30(7), 1635; https://doi.org/10.3390/molecules30071635 - 6 Apr 2025

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Abstract

This study was conducted to identify the optimal conditions and evaluate the feasibility of deep eutectic solvent (DES)-based ultrasound-assisted extraction (UAE) for utilizing maca (Lepidium meyenii) leaves, an agricultural by-product, as functional materials. The extraction parameters influencing the recovery of saponins [...] Read more.

This study was conducted to identify the optimal conditions and evaluate the feasibility of deep eutectic solvent (DES)-based ultrasound-assisted extraction (UAE) for utilizing maca (Lepidium meyenii) leaves, an agricultural by-product, as functional materials. The extraction parameters influencing the recovery of saponins and polyphenols, which are major bioactive compounds, were analyzed using the Taguchi method. Results: Signal-to-noise ratios and analysis of variance indicated that the liquid–solid ratio was the most critical factor for optimizing the extraction process. The optimal extraction conditions were determined to be a liquid–solid ratio of 40 mL/g, a water content in DES of 30%, an extraction time of 30 min, and an ultrasonic power of 300 W in the DES system consisting of choline chloride and glycerin in the molar ratio of 1:2. Maca leaf extract obtained under optimized DES-based UAE conditions exhibited higher bioactive compounds content and antioxidant activity compared with that obtained by hot water extraction. Therefore, the DES-based UAE method is a promising, eco-friendly alternative for extracting bioactive compounds from maca leaves. Full article

(This article belongs to the Special Issue Microwave and Ultrasound-Assisted Extraction for Plant Bioactive Compounds)

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20 pages, 1803 KiB

Open AccessArticle

Exploring the Influence of a Pomegranate Extract on the Functionality of Healthy and Diseased Human Gut Microbiota: An In Vitro Study

by Daniele Giuseppe Buccato, Adriana Delgado-Osorio, Lorenza Francesca De Lellis, Maria Vittoria Morone, Hammad Ullah, Luana Izzo, Sonia Lombardi, Alessandro Di Minno, Costanza Valentina Riccioni, Dafni Moriki, José Ángel Rufián-Henares and Maria Daglia

Molecules 2025, 30(7), 1634; https://doi.org/10.3390/molecules30071634 - 6 Apr 2025

Viewed by 127

Abstract

Pomegranate is recognized for its health benefits, primarily due to its polyphenols and metabolites, such as urolithins (Uro-A), produced via colonic fermentation of ellagic acid (EA). These compounds make pomegranate a functional food with the potential to modulate chronic disease risk factors and [...] Read more.

Pomegranate is recognized for its health benefits, primarily due to its polyphenols and metabolites, such as urolithins (Uro-A), produced via colonic fermentation of ellagic acid (EA). These compounds make pomegranate a functional food with the potential to modulate chronic disease risk factors and enhance gut health by modulating microbiota. The aims of this study were (1) to evaluate the effect of in vitro digestion and fermentation mimicking human digestive processes on the total phenolic content (TPC) and the antioxidant capacity of a standardized pomegranate extract (PE), (2) to assess the effect of the digested PE on the functionality of gut microbiota isolated from healthy and diseased subject fecal materials via short-chain fatty acid (SCFA) determination, and (3) to measure Uro-A production using UHPLC Q-Orbitrap HRMS. The in vitro digestion and fermentation processes resulted in a significant increase in the TPC, while the antioxidant capacity was considerably reduced. Following the in vitro digestion process, the TPC increased from 232 ± 16 to 1656 ± 34 g GAE/g of PE. Moreover, the TPC in the fermented samples was calculated as 6139 ± 458 g GAE/g for the microbiota of healthy adults and 8375 ± 1388 g GAE/g for the microbiota of healthy children, compared to 1657 ± 34 g GAE/g for the non-fermented samples. The PE exerted a modulatory effect on gut microbiota functionality, as reflected by an increasing concentration of SCFAs, especially lactic acid. Overall, these data suggest that pomegranate might contribute to gut health and could be a candidate for further studies in view of its possible use as a prebiotic ingredient. Further research, including clinical studies, is needed to confirm these findings and explore the potential application of pomegranate extract as a functional ingredient in nutraceuticals and functional foods aimed at improving gut health. Full article

(This article belongs to the Special Issue Exploring Bioactive Polyphenolic Compounds in Food and Natural Real-World Samples II)

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17 pages, 1392 KiB

Open AccessFeature PaperArticle

Spectroscopic and Microscopic Analysis of Apple Pectins

by Agata Serrafi, Agnieszka Wikiera, Konrad Cyprych and Magdalena Malik

Molecules 2025, 30(7), 1633; https://doi.org/10.3390/molecules30071633 - 6 Apr 2025

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Abstract

Apple pomace pectins, extracted using various methods (water, cellulase, arabinase, and arabinase with mannanase), and commercial apple pectin were studied, analyzing their morphology and chemical structure. The microscopic analysis revealed morphological differences, with a log-normal particle size distribution observed in most samples, except [...] Read more.

Apple pomace pectins, extracted using various methods (water, cellulase, arabinase, and arabinase with mannanase), and commercial apple pectin were studied, analyzing their morphology and chemical structure. The microscopic analysis revealed morphological differences, with a log-normal particle size distribution observed in most samples, except for those extracted with water. Cellulase-extracted pectin exhibited the most spherical morphology, while enzymatically extracted pectins displayed uneven surfaces. The FT-IR analysis indicated structural changes, shifts in O-H bands, and the degree of methoxylation (DM) ranged from 30.25% to 58%, with all the pectins classified as high-methoxy pectins. The NMR (¹H and ¹³C) analysis confirmed the presence of arabinans, galactans, galacturonans, and rhamnose, and the calculated DM and acetylation (DAc) values were consistent with the results obtained using conventional methods. These results provide insight into the influence of extraction methods on pectin properties, which is relevant to the pharmaceutical and food industries, and confirm the structural similarity between enzymatically extracted pectins and commercial pectin. Full article

(This article belongs to the Section Natural Products Chemistry)

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13 pages, 2411 KiB

Open AccessArticle

Polyketides with Cardioprotective Bioactivities from Sponge-Associated Fungus Aspergillus giganteus MA46-5

by Ying-Tong Lin, Xiao-Wei Yao, Zheng-Wu Luo, Wei-Xin Jiang, Yin-Fei Wu, Ze-Jun Li, Xue-Wei Duan, Meng-Dan Zhang, Yuan-Yuan Cheng and Cui-Xian Zhang

Molecules 2025, 30(7), 1632; https://doi.org/10.3390/molecules30071632 - 6 Apr 2025

Viewed by 94

Abstract

One pair of novel enantiomers, gigantdioxin A (+)-1 and B (−)-1, with a skeleton of benzo[d][1,3]dioxin; a new acetophenone gigantone A (3); a known 3-chlorogentisyl alcohol (2), which is the bioprecursor of 1; [...] Read more.

One pair of novel enantiomers, gigantdioxin A (+)-1 and B (−)-1, with a skeleton of benzo[d][1,3]dioxin; a new acetophenone gigantone A (3); a known 3-chlorogentisyl alcohol (2), which is the bioprecursor of 1; acetophenone (4); and chromone derivative (5) were obtained from the sponge-associated fungus Aspergillus giganteus MA46-5. Their structures were established by extensive and in-depth spectral analysis, such as UV, 1D and 2D NMR, and HRESIMS. The absolute configurations of (±)-1 were deduced by ORD, chiral separation, and experimental and computational ECD. Meanwhile, we proposed a possible biosynthetic pathway of (±)-1. Fortunately, the pathway was proved by biomimetic synthesis through 2, as a bioprecursor, reacted with n-butyraldehyde. Myocardial protection assays showed that 3 and 4 possessed stronger protective effects than a positive control against myocardial cell H9c2 ischemia–reperfusion injury in low concentrations, and the effect of (−)-1 was almost equal to that of the positive control. Further, we explored the possible mechanism of myocardial protection through network pharmacology. Adenosine A2a receptor (ADORA2A) and serum albumin (ALB) represent potential targets for myocardial protection associated with (−)-1 and 4, respectively. Based on the network pharmacology, we docked the predicted proteins with bioactive compounds using Autodock Vina. Full article

(This article belongs to the Special Issue Bioactive Metabolites from Marine Invertebrates and Their Associated Microorganisms—in Celebration of Professors Longmei Zeng and Jingyu Su’s 95th Birthday)

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10 pages, 7463 KiB

Open AccessArticle

Enhanced Compressive Strength of PVA/SA Composite Hydrogel by Highly Dispersed Hydroxyapatite Nanofibers

by Shuochao You, Shan Zhang, Yahao Geng, Tianhao Wu and Guiyong Xiao

Molecules 2025, 30(7), 1631; https://doi.org/10.3390/molecules30071631 - 6 Apr 2025

Viewed by 71

Abstract

Rapid functional soft tissue restoration has shown considerable promise as a framework for stability and coordination in the human body. Inspired by the anisotropic arrangement of structures with soft and hard phases in biological tissues, such as tendon, cartilage, and ligament, many methods [...] Read more.

Rapid functional soft tissue restoration has shown considerable promise as a framework for stability and coordination in the human body. Inspired by the anisotropic arrangement of structures with soft and hard phases in biological tissues, such as tendon, cartilage, and ligament, many methods have been used to fabricate composite hydrogels with appropriate mechanical properties. The development of a high-strength hydrogel with strong bioactivity remains a key barrier to replace soft tissues with comparable synthetic structures. In this study, a highly dispersed hydroxyapatite nanofiber (HANF) reinforced polyvinyl alcohol-sodium alginate (PVA/SA) composite hydrogel is prepared for soft tissue replacement. The effect of the addition of HANF on the microstructure and properties of composite hydrogel is also investigated. The results show that the PVA/SA hydrogel, after the incorporation of HANF, combines well with the PVA/SA hydrogel (HANF@PVA/SA). SEM morphologies show that dispersed HANF can enter the holes of the three-dimensional structure of the composite hydrogel. Additionally, the addition of HANF can enhance the compressive strength of the PVA/SA composite hydrogel from 4.66 MPa to 7.72 MPa. At the same time, the HANF@PVA/SA hydrogel maintains the same excellent hydrophilicity as the original PVA/SA hydrogel. Finally, cytotoxicity and live/dead cell staining tests also confirmed its excellent biocompatibility, demonstrating its tremendous potential for use in soft tissue repair. Full article

(This article belongs to the Special Issue Physicochemical Research on Material Surfaces)

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14 pages, 3798 KiB

Open AccessReview

Recent Progress in Dimerized Small-Molecular Acceptors for Organic Solar Cells

by Xin Tang, Yamin Zhang and Hao-Li Zhang

Molecules 2025, 30(7), 1630; https://doi.org/10.3390/molecules30071630 - 6 Apr 2025

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Abstract

Organic solar cells (OSCs) have witnessed significant advancements in recent years, largely propelled by innovations in material design and device engineering. Among the emerging materials, dimerized small-molecule acceptors (DSMAs) have garnered considerable attention due to their unique advantages. For instance, DSMAs can directly [...] Read more.

Organic solar cells (OSCs) have witnessed significant advancements in recent years, largely propelled by innovations in material design and device engineering. Among the emerging materials, dimerized small-molecule acceptors (DSMAs) have garnered considerable attention due to their unique advantages. For instance, DSMAs can directly inherit the excellent optoelectronic properties of corresponding small-molecule monomers. Moreover, their relatively larger molecular weight can effectively suppress molecular diffusion in the active layer, thereby enhancing the stability of OSCs. Compared to polymer acceptors, DSMAs have a well-defined structure, which is free from batch-to-batch variability, greatly enhancing the reproducibility of devices. This review comprehensively summarizes recent progress in DSMAs for OSCs, with a focus on their two primary linkage configurations: conjugative and non-conjugative connections. Additionally, the impact of various connection positions (including core-unit, end-group, and side-chain connection sites) on molecular packing, optoelectronic properties, and device performance is systematically reviewed. The review highlights the critical role of DSMAs in addressing key challenges in OSCs, such as photodegradation and morphological instability, while balancing power conversion efficiency and long-term stability. By consolidating recent breakthroughs and identifying future research directions, this work aims to provide valuable insights into the rational design of DSMAs, paving the way for the development of high-performance and commercially viable OSCs. Full article

(This article belongs to the Section Materials Chemistry)

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44 pages, 4429 KiB

Open AccessReview

Current Analytical Strategies for mRNA-Based Therapeutics

by Julien Camperi, Kamalakar Chatla, Emily Freund, Carolina Galan, Steffen Lippold and Axel Guilbaud

Molecules 2025, 30(7), 1629; https://doi.org/10.3390/molecules30071629 - 6 Apr 2025

Viewed by 1018

Abstract

Recent advancements in mRNA technology, utilized in vaccines, immunotherapies, protein replacement therapies, and genome editing, have emerged as promising and increasingly viable treatments. The rapid, potent, and transient properties of mRNA-encoded proteins make them attractive tools for the effective treatment of a variety [...] Read more.

Recent advancements in mRNA technology, utilized in vaccines, immunotherapies, protein replacement therapies, and genome editing, have emerged as promising and increasingly viable treatments. The rapid, potent, and transient properties of mRNA-encoded proteins make them attractive tools for the effective treatment of a variety of conditions, ranging from infectious diseases to cancer and single-gene disorders. The capability for rapid and large-scale production of mRNA therapeutics fueled the global response to the COVID-19 pandemic. For effective clinical implementation, it is crucial to deeply characterize and control important mRNA attributes such as purity/integrity, identity, structural quality features, and functionality. This implies the use of powerful and advanced analytical techniques for quality control and characterization of mRNA. Improvements in analytical techniques such as electrophoresis, chromatography, mass spectrometry, sequencing, and functionality assessments have significantly enhanced the quality and detail of information available for product and process characterization, as well as for routine stability and release testing. Here, we review the latest advancements in analytical techniques for the characterization of mRNA-based therapeutics, typically employed by the biopharmaceutical industry for eventual market release. Full article

(This article belongs to the Section Analytical Chemistry)

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25 pages, 4437 KiB

Open AccessArticle

The Antiproliferative Activity and NO Inhibition of Neo-Clerodane Diterpenoids from Salvia guevarae in RAW 264.7 Macrophages

by Juan Pablo Torres-Médicis, Celia Bustos-Brito, Leovigildo Quijano, Brenda Y. Bedolla-García, Sergio Zamudio, Teresa Ramírez-Apan, Diego Martínez-Otero and Baldomero Esquivel

Molecules 2025, 30(7), 1628; https://doi.org/10.3390/molecules30071628 - 5 Apr 2025

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Abstract

In this study, nine neo-clerodane-type diterpenoids (1–9) were isolated from the dichloromethane extract of Salvia guevarae Bedolla & Zamudio leaves. Compounds 1–6 were new natural products, and 7–9 were acetone artifacts. In addition, four [...] Read more.

In this study, nine neo-clerodane-type diterpenoids (1–9) were isolated from the dichloromethane extract of Salvia guevarae Bedolla & Zamudio leaves. Compounds 1–6 were new natural products, and 7–9 were acetone artifacts. In addition, four neo-clerodanes diterpenoids (10–13) previously described from different sources and six triterpenoids—identified as 3β,20,25-trihydroxylupane, oleanolic acid, 3β-O-acetyl-oleanolic acid, ursolic acid, 3β-O-acetyl-betulinic acid, and 3β,28-O-diacetyl-betulin—were isolated. Additionally, five flavonoids were also isolated from the methanol extract: quercetin-3-O-β-xylopyranosyl-(1 → 2)-β-galactopyranoside, taxifolin-7-O-β-glucopyranoside, naringenin-7-O-β-glucopyranoside, a mixture of 2R and 2S eriodictyol-7-O-β-glucopyranoside, caffeic acid, the methyl ester of rosmarinic acid, and rosmarinic acid. The structure of the isolated compounds was established by spectroscopic means, mainly ¹H and ¹³C NMR, including 1D and 2D homo- and heteronuclear experiments. The absolute configuration of 1 and 10 was ascertained via an X-ray analysis, and that of the other compounds via ECD. The antiproliferative activity of some diterpenoids was determined using the sulforhodamine B method, where guevarain B (2) and 6α-hydroxy-patagonol acetonide (7) showed moderate activity against the K562 line, with IC₅₀ (μM) = 33.1 ± 1.3 and 39.8 ± 1.5, respectively. The NO inhibition in RAW 264.7 macrophage activity was also determined for some compounds, where 2-oxo-patagonal (6), 6α-hydroxy-patagonol acetonide (7), and 7α-acetoxy-ent-clerodan-3,13-dien-18,19:16,15-diolide (10) were proven to be active, with IC₅₀ (μM) of 26.4 ± 0.4, 17.3 ± 0.5, and 13.7 ± 2.0, respectively. The chemotaxonomy of Salvia guevarae is also discussed. Full article

(This article belongs to the Special Issue Natural Products with Pharmaceutical Activities)

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32 pages, 3830 KiB

Open AccessArticle

Oxidation of α-Pinene on the Ti-SBA-15 Catalyst Obtained Using Orange Peel Waste as Components of the Synthesis Gel

by Jadwiga Grzeszczak, Agnieszka Wróblewska, Beata Michalkiewicz, Małgorzata Dzięcioł and Katarzyna Janda-Milczarek

Molecules 2025, 30(7), 1627; https://doi.org/10.3390/molecules30071627 - 5 Apr 2025

Viewed by 96

Abstract

α-Pinene is a very valuable natural raw material for organic syntheses, which is of increasing interest to scientists due to its renewability and relatively low price. This work presents the studies on the oxidation of α-pinene in the presence of two mesoporous titanium-silicate [...] Read more.

α-Pinene is a very valuable natural raw material for organic syntheses, which is of increasing interest to scientists due to its renewability and relatively low price. This work presents the studies on the oxidation of α-pinene in the presence of two mesoporous titanium-silicate catalysts: standard Ti-SBA-15 and Ti-SBA-15 material, which was obtained by a new and green way using orange peel waste as bio-templates (Ti-SBA-15_orange peels). For the synthesis of the Ti-SBA-15 catalysts, the following raw materials were used: Pluronic P123 as the template (template usually used in the synthesis of SBA-15 materials), tetraethyl orthosilicate as the silicon source, hydrochloric acid, deionized water, and tetraisopropyl orthotitanate as the titanium source. For the synthesis of Ti-SBA-15_orange peels, a catalyst was also properly prepared, and orange peel waste as the co-templates (renewable templates) were used. The two obtained Ti-SBA-15 materials were characterized by the following instrumental methods: XRD, SEM, EDX, UV-Vis, and FTIR. Moreover, the specific surface area and pore size distribution were investigated for these catalysts with help from the nitrogen adsorption–desorption method. Catalytic tests of the obtained catalysts were performed in the oxidation of α-pinene with oxygen and by the method which did not use any solvent (α-pinene was simultaneously the raw material and solvent in this process). During the catalytic tests, the effect of temperature, catalyst content, and reaction time on the selectivities of the appropriate products and the conversion of α-pinene were studied. Depending on the conditions of the oxidation process, the catalyst obtained with the use of orange peels as co-templates showed similar or even higher activity than the standard Ti-SBA-15 catalyst. Full article

(This article belongs to the Special Issue 10th Anniversary of Green Chemistry Section)

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13 pages, 1735 KiB

Open AccessArticle

Selective Activity of Chrysin-6-C-Fucopyranoside from Cyclanthera pedata Toward Peroxisome Proliferator-Activated Receptor Gamma

by Marco Zuccolo, Angela Bassoli, Gigliola Borgonovo, Luca Giupponi, Annamaria Giorgi, Aniello Schiano Moriello and Fabio Arturo Iannotti

Molecules 2025, 30(7), 1626; https://doi.org/10.3390/molecules30071626 - 5 Apr 2025

Viewed by 137

Abstract

Caigua (Cyclanthera pedata (L.) Schrad.) is a traditional herbal remedy traditionally used in Latin America for its health benefits and to treat metabolic disorders, including diabetes. Despite interest in its herbal use, the phytochemical properties of caigua’s secondary metabolites are poorly known. [...] Read more.

Caigua (Cyclanthera pedata (L.) Schrad.) is a traditional herbal remedy traditionally used in Latin America for its health benefits and to treat metabolic disorders, including diabetes. Despite interest in its herbal use, the phytochemical properties of caigua’s secondary metabolites are poorly known. This study aimed to isolate the main flavone glycosides from the leaves of caigua landrace cultivated in the Camonica Valley (Italy) using flash chromatography and evaluate their potential activity toward peroxisome proliferator-activated receptors (PPARs) and transient receptor potential (TRP) ion channels through luciferase and intracellular calcium assays. We found that the caigua species-specific flavone glycoside, chrysin-6-C-fucopyranoside, showed potent and selective activity toward PPARγ, with no effects on other PPAR subtypes or TRP channels. These findings indicate that the caigua plant could offer a safer alternative to conventional PPARγ agonists, whose use as antidiabetic drugs is limited by severe side effects that currently restrict the clinical use of conventional PPAR agonists. Full article

(This article belongs to the Special Issue Extraction, Isolation, and Identification of Bioactive Compounds from Plants)

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18 pages, 7546 KiB

Open AccessArticle

Few-Layered MXene Modulating In Situ Growth of Carbon Nanotubes for Enhanced Microwave Absorption

by Qing Tang, Qi Fan, Lei He, Ping Yu, Qing Huang, Yuanming Chen, Bingbing Fan and Kun Liang

Molecules 2025, 30(7), 1625; https://doi.org/10.3390/molecules30071625 - 5 Apr 2025

Viewed by 99

Abstract

MXene is widely used in the fields of microwave absorption and electromagnetic shielding to balance electromagnetic pollution with the development of communication technologies and human health, due to its excellent surface functional groups and tunable electronic properties. Although pure multilayered MXene has an [...] Read more.

MXene is widely used in the fields of microwave absorption and electromagnetic shielding to balance electromagnetic pollution with the development of communication technologies and human health, due to its excellent surface functional groups and tunable electronic properties. Although pure multilayered MXene has an excellent accordion-like structure, the weak dielectric loss and lack of magnetic loss result in poor microwave absorption performance. Here, we propose a strategy for the catalytic growth of CNTs by the electrophoretic deposition of adsorbed metal ions, leading to the successful preparation of Ni-MWCNTs/Ti₃C₂T_x composites with a “layer-by-layer” structure, achieved through in situ regulated growth of CNTs. By introducing dielectric–magnetic synergy to improve the impedance matching conditions, and by regulating the diameter of the CNTs to alter the electromagnetic parameters of Ni-MWCNTs/Ti₃C₂T_x, the 2-Ni-MWCNTs/Ti₃C₂T_x composite achieves the best reflection loss (RL) value of −44.08 dB and an effective absorption bandwidth of 1.52 GHz at only 2.49 mm thickness. This unique layered structure and the regulation strategy provide new opportunities for the development of few-layered MXene composites. Full article

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20 pages, 2510 KiB

Open AccessArticle

Development of Vancomycin, a Glycopeptide Antibiotic, in a Suitable Nanoform for Oral Delivery

by Ali A. Amer, Lewis Bingle, Cheng Shu Chaw and Amal Ali Elkordy

Molecules 2025, 30(7), 1624; https://doi.org/10.3390/molecules30071624 - 5 Apr 2025

Viewed by 111

Abstract

Bacterial infections caused by resistant strains have emerged as one of the most significant life-threatening challenges. Developing alternatives to conventional antibiotic formulations is crucial to overcoming these challenges. Vancomycin HCl (VCM) is a glycopeptide antibiotic used for Gram-positive bacterial infections that must be [...] Read more.

Bacterial infections caused by resistant strains have emerged as one of the most significant life-threatening challenges. Developing alternatives to conventional antibiotic formulations is crucial to overcoming these challenges. Vancomycin HCl (VCM) is a glycopeptide antibiotic used for Gram-positive bacterial infections that must be given intravenously for systemic infections since it cannot pass through the gut wall due to its chemical structure and characteristics. The aim of this research is to develop VCM in a niosomal nanoform to then be encapsulated in fast-disintegrating oral films for effective delivery to enhance the application of vancomycin-loaded niosomes for treating oral infections and to be used in dental treatments. The formulation of niosomes encapsulating VCM was conducted with various ratios of Span 40, Span 60, and cholesterol as well as Kolliphor RH40 and Kolliphor ELP as co-surfactants using the microfluidic technique. The prepared niosomes were characterised using dynamic light scattering (DLS) for their size determination; high-pressure liquid chromatography, HPLC, for drug encapsulation efficiency determination; and the agar diffusion method for the determination of the antibacterial efficacy of the VCM niosomes against Bacillus subtilis. The niosomal formulation was then incorporated into polyvinyl alcohol (PVA) film, and the properties of the oral film were characterised by in vitro assays. The vancomycin-loaded niosomes produced with optimal conditions exhibited small diameter with acceptable polydispersity index, and drug encapsulation efficiency. This study presents multifunctional niosomes loaded with VCM, which demonstrated efficient in vitro activity against Gram-positive bacteria upon the slow release of VCM from niosomes, as demonstrated by the dissolution test. Oral films containing VCM niosomes demonstrated uniform weights and excellent flexibility with high foldability and a rapid disintegration time of 105 ± 12 s to release the niosomal content. This study showed that the microfluidic approach could encapsulate VCM, a peptide in salt form, in surfactant-based niosomal vesicles with a narrow size distribution. The incorporation of niosomes into fast-disintegrating film provides a non-invasive and patient-friendly alternative for treating bacterial infections in the oral cavity, making it a promising approach for dental and systemic applications. Full article

(This article belongs to the Special Issue Molecular Approaches to Drug Discovery and Development)

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15 pages, 6422 KiB

Open AccessArticle

pH-Induced Conformational Change of the Chromophore of the Large Stokes Shift Fluorescent Protein tKeima

by Yongbin Xu, Yun Gyo Seo, In Jung Kim and Ki Hyun Nam

Molecules 2025, 30(7), 1623; https://doi.org/10.3390/molecules30071623 - 5 Apr 2025

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Abstract

Fluorescent proteins (FPs) are widely used as optical probes in molecular and cell biology. tKeima is a tetrameric, large Stokes shift red fluorescent protein and the ancestral protein of mt-Keima, which is widely applied as a pH-sensitive fluorescent probe. While the pH sensitivity [...] Read more.

Fluorescent proteins (FPs) are widely used as optical probes in molecular and cell biology. tKeima is a tetrameric, large Stokes shift red fluorescent protein and the ancestral protein of mt-Keima, which is widely applied as a pH-sensitive fluorescent probe. While the pH sensitivity of mt-Keima is well characterized, the pH-dependent properties of the ancestral tKeima have not been comprehensively elucidated. To obtain a better understanding of the effects of pH on tKeima, its fluorescent emission intensity at various pH levels was measured, and its crystal structure at pH 4.0 was determined at a resolution of 2.2 Å. The fluorescence emission intensity of tKeima at pH 4.0 decreased by approximately 65% compared with its peak emission at pH 10.0. The crystal structure of tKeima at pH 4.0 revealed both cis and trans conformations of the chromophore, in contrast to previously determined structures at pH 8.0, which showed only the cis conformation. This indicates that pH induces a conformational change of the chromophore in tKeima. Both the cis and trans conformations in tKeima were stabilized by hydrogen bonds with neighboring residues. A comparison of tKeima at pH 4.0 with tKeima at basic pH, as well as with mKeima, highlights its unique structural properties. These results provide a deeper understanding of the structural basis for the pH-induced fluorescence emission changes in the Keima family. Full article

(This article belongs to the Section Molecular Structure)

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16 pages, 3298 KiB

Open AccessFeature PaperArticle

Extraction, Preparation and Characterization of Nanocrystalline Cellulose from Lignocellulosic Simpor Leaf Residue

by Ukashat Mamudu, Asset Kabyshev, Kenzhebatyr Bekmyrza, Kairat A. Kuterbekov, Aliya Baratova, Lukman Ahmed Omeiza and Ren Chong Lim

Molecules 2025, 30(7), 1622; https://doi.org/10.3390/molecules30071622 - 5 Apr 2025

Viewed by 110

Abstract

In this study, α-cellulose was extracted from lignocellulosic simpor leaf residue as a sustainable alternative to conventional cellulose sources. The extraction process involved the removal of hemicellulose, lignin, and other phytocompounds using alkali (NaOH) treatment and bleaching with hydrogen peroxide (H₂O [...] Read more.

In this study, α-cellulose was extracted from lignocellulosic simpor leaf residue as a sustainable alternative to conventional cellulose sources. The extraction process involved the removal of hemicellulose, lignin, and other phytocompounds using alkali (NaOH) treatment and bleaching with hydrogen peroxide (H₂O₂). The nanocrystalline cellulose (NCC) was isolated from α-cellulose using sulfuric acid hydrolysis treatment followed by ultrasonication. The extracted α-cellulose and isolated NCC were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and dynamic light scattering (DLS). The obtained results confirmed that the extracted NCC exhibited characteristic cellulose functional groups and a crystallinity index of 64.7%, indicating the effective removal of amorphous regions through sulfuric acid hydrolysis. The thermal stability of the extracted cellulose increased to 332 °C due to the elimination of extractives. DLS analysis showed that the extracted NCC exhibited high colloidal stability in polar solvents, characterized by a zeta potential of −70.8 mV and an average particle size of 251.7 nm. This study highlights an environmentally friendly approach for converting low-value biomass waste into high-value cellulose materials with potential applications in sustainable packaging, biomedical applications and composite reinforcement. Full article

(This article belongs to the Section Materials Chemistry)

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22 pages, 2237 KiB

Open AccessArticle

Development and Perfection of Marine-Based Insecticide Biofilm for Pea Seed Protection: Experimental and Computational Approaches

by Fatouma Mohamed Abdoul-Latif, My Ismail El Mhamdi, Ayoub Ainane, Ali Merito Ali, Khadija Oumaskour, Sanaa Cherroud, Stefano Cacciatore and Tarik Ainane

Molecules 2025, 30(7), 1621; https://doi.org/10.3390/molecules30071621 - 4 Apr 2025

Viewed by 108

Abstract

This work aims to develop an insecticidal biofilm based on Calothrixin A, collagen, and chitosan for the protection of pea seeds. The main objective is to improve the ingredient concentrations maximizing the insecticidal activity of the biofilm and to study the desorption of [...] Read more.

This work aims to develop an insecticidal biofilm based on Calothrixin A, collagen, and chitosan for the protection of pea seeds. The main objective is to improve the ingredient concentrations maximizing the insecticidal activity of the biofilm and to study the desorption of Calothrixin A according to the diffusion parameters. Eight biofilm formulations were prepared with different concentrations of the components and tested on Sitona lineatus and Bruchus pisorum. The results show that a high concentration of Calothrixin A tended to increase insecticidal activity, although this increase was not always significant, while a higher concentration of collagen and chitosan reduced insecticidal activity, probably by limiting the diffusion of the active ingredient. The prediction models for insecticidal activity showed that the interaction of the factors had no significant impact on the responses, but the model for Sitona lineatus presented better accuracy. The diffusion tests revealed that the CB3C-5 biofilm, with high diffusion parameters, correlated with insecticidal activity. The characterization of the CB3C-5 biofilm showed adequate physical, mechanical, thermal, and structural properties for agricultural seed storage application. Moreover, the computational approach showed that Calothrixin A interacts more efficiently with the OR5-Orco complex than with the small OBP, disrupting the olfactory detection of insects. This mechanism highlights the targeting of the olfactory complex as a potential strategy to control insect pests. This research contributes to the understanding of the role of marine-based biofilms for seed protection and opens perspectives for the development of ecological solutions against insect pests, particularly in the field of sustainable agriculture. Full article

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15 pages, 5254 KiB

Open AccessArticle

Impact of Co-Inoculation Patterns of Wickerhamomyces anomalus and Saccharomyces cerevisiae on Cider Quality and Aromatic Profiles

by Yue Wei, Jianguo Mou, Haoran Zhang, Aiying Gao and Yi Qin

Molecules 2025, 30(7), 1620; https://doi.org/10.3390/molecules30071620 - 4 Apr 2025

Viewed by 57

Abstract

Co-inoculation with Saccharomyces cerevisiae and non-Saccharomyces yeasts is an effective method to improve the flavor of cider. Wickerhamomyces anomalus, known for its high ester production capacity, was evaluated in combination with S. cerevisiae to identify optimal mixed yeast inoculants for improved [...] Read more.

Co-inoculation with Saccharomyces cerevisiae and non-Saccharomyces yeasts is an effective method to improve the flavor of cider. Wickerhamomyces anomalus, known for its high ester production capacity, was evaluated in combination with S. cerevisiae to identify optimal mixed yeast inoculants for improved sensory characteristics. Three W. anomalus strains and three inoculation ratio attributes (1:5, 1:1, and 5:1) were tested to assess their impact on the physicochemical indices and sensory attributes of cider. All the strains used as starters developed fermentation-producing ciders with alcoholic degrees between 6.22 and 6.36 (% v/v). Co-inoculation with W. anomalus resulted in significantly higher ester, volatile acid, and higher alcohol levels compared to those of S. cerevisiae monocultures, increasing the complexity of fruity and floral aromas. Furthermore, the proportion of W. anomalus strains in the inoculations was positively correlated with increased aromatic esters and higher alcohols. The Sc–Wa (1:5) cider showed the highest contents of ethyl ethanoate and 3-methylbutan-1-ol, contributing to a nail polish-like aroma. Sc–Wa (1:1) yielded a higher aromatic diversity than did Sc–Wa (5:1), suggesting that co-inoculation with a ratio of 1:1 may provide an effective fermentation strategy for cider aroma enhancement. These findings offer valuable insights into how non-Saccharomyces yeasts can be effectively applied in cider co-fermentation, providing a foundation for their future use in industrial applications. Full article

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22 pages, 4821 KiB

Open AccessArticle

Evaluation of Film-Forming Properties of α-1,3-Glucan Obtained from “Chicken of the Woods” Mushroom (Laetiporus sulphureus): Film Development, Characterization, and Biodegradation Assessment

by Kowalczyk Dariusz, Barbara Gieroba, Katarzyna Niedźwiadek, Mikołaj Krysa, Anna Sroka-Bartnicka, Adam Waśko, Ewa Ozimek, Aleksandra Ściegienna, Monika Basiura-Cembala, Waldemar Kazimierczak and Adrian Wiater

Molecules 2025, 30(7), 1619; https://doi.org/10.3390/molecules30071619 - 4 Apr 2025

Viewed by 122

Abstract

Unlike many biopolymers, α-1,3-glucan (α-1,3-GLU) is water-insoluble, making it a promising candidate for the production of moisture-resistant films with applications in biodegradable packaging, biomedicine, and cosmetics. This study aimed to characterize the structural, physicochemical (water affinity, optical, mechanical), and biodegradation properties of a [...] Read more.

Unlike many biopolymers, α-1,3-glucan (α-1,3-GLU) is water-insoluble, making it a promising candidate for the production of moisture-resistant films with applications in biodegradable packaging, biomedicine, and cosmetics. This study aimed to characterize the structural, physicochemical (water affinity, optical, mechanical), and biodegradation properties of a film made from α-1,3-GLU extracted from Laetiporus sulphureus. The film was fabricated through alkaline dissolution, casting, drying, washing to remove residual NaOH, and re-plasticization with a glycerol solution. FTIR and Raman spectroscopy confirmed the polysaccharide nature of the film, with predominant α-glycosidic linkages. The film exhibited a semi-crystalline structure and high opacity due to surface roughness resulting from polymer coagulation. Owing to re-plasticization, the film showed a high moisture content (~47%), high water solubility (81.95% after 24 h), and weak mechanical properties (tensile strength = 1.28 MPa, elongation at break ≈ 10%). Its water vapor permeability (53.69 g mm m⁻² d⁻¹ kPa⁻¹) was comparable to other glycerol-plasticized polysaccharide films reported in the literature. The film supported the adhesion of soil microorganisms and target bacteria and was susceptible to degradation by Trichoderma harzianum and endo- and exo-α-1,3-glucanases, indicating its biodegradability. The limitations in its mechanical strength and excessive hydration indicate the need for improvements in the composition and methods of producing α-1,3-GLU films. Full article

(This article belongs to the Special Issue Chitosan, Chitosan Derivatives, Polysaccharides and Their Applications—2nd Edition)

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Molecules, Volume 30, Issue 7 (April-1 2025) – 252 articles

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