Molecules

21 pages, 3870 KB

Open AccessArticle

Response of Human Red Blood Cells to Acute and Chronic Oxidant Challenge as Observed Through the Glutathione and Glutathionyl-Hemoglobin Redox Pairs In Vitro and In Vivo

by Federico Maria Rubino

Molecules 2026, 31(5), 811; https://doi.org/10.3390/molecules31050811 (registering DOI) - 28 Feb 2026

Abstract

Glutathionyl-hemoglobin (HbSSG) reversibly forms under oxidative stress in erythrocytes, where it constitutes the main redox buffer, in a dynamic equilibrium with the thiol (GSH) and disulfide (GSSG) forms of glutathione, that quickly revert to the reduced thiols when oxidative pressure is relieved. Under [...] Read more.

Glutathionyl-hemoglobin (HbSSG) reversibly forms under oxidative stress in erythrocytes, where it constitutes the main redox buffer, in a dynamic equilibrium with the thiol (GSH) and disulfide (GSSG) forms of glutathione, that quickly revert to the reduced thiols when oxidative pressure is relieved. Under acute challenge, the “oxidized” GSH pool distributes between GSSG and HbSSG. Recalculation with electrochemical metrics based on redox potentials of the GSSG/GSH and HbSSG/HbSH pairs, plotted in their phase space, improves the understanding of the competing reduction processes. The first process is reduction of the GSSG pool, while, later, HbSSG reduction occurs as a two-step process. HbSSG accumulation in chronic oxidative stress follows an impairment of these steps. In 30 strong smokers, homogeneous levels of HbSSG are in the range of 2.4–11.7% (E_h −120–−95 mV), but the E_h of the GSSG/GSH redox pair is wider (−160–−240 mV), suggesting that HbSSG accumulation does not depend on GSH availability but on enzyme activity impaired by exogenous and endogenous electrophiles. As hinted by HbSSG measurements, one such species is the dehydro-alanine analog of GSH, produced both from butadiene in exposed petrochemical workers and from the drug busulfan in a treated patient. Inactivation of the low-copy recycling enzymes can thus explain the increase of HbSSG. Full article

(This article belongs to the Section Analytical Chemistry)

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14 pages, 2804 KB

Open AccessArticle

Effects of Different Processing Methods on the Quality and Flavor Characteristics of Shiqi Pigeon (Columba livia domestica) Meat

by Weina Li, Xinlan Cao, Siqi Ming, Yongjie Xu, Zhuoxian Weng, Haitang Wang and Xiaonan Zhang

Molecules 2026, 31(5), 810; https://doi.org/10.3390/molecules31050810 (registering DOI) - 28 Feb 2026

Abstract

This study investigated the effects of boiling, roasting, and frying on the quality and flavor characteristics of Shiqi pigeon (Columba livia domestica) meat. Changes in color, texture, microstructure, and volatile profiles were systematically evaluated using colorimetry, texture profile analysis, scanning electron [...] Read more.

This study investigated the effects of boiling, roasting, and frying on the quality and flavor characteristics of Shiqi pigeon (Columba livia domestica) meat. Changes in color, texture, microstructure, and volatile profiles were systematically evaluated using colorimetry, texture profile analysis, scanning electron microscopy, electronic nose analysis, and Fourier transform infrared spectroscopy (FTIR). Thermal processing significantly influenced physicochemical properties and flavor profiles. Fried samples exhibited the highest hardness (27.79 N), chewiness (33.13 mJ), and maximum shear force (30.23 N), while boiled samples showed the lowest hardness (22.12 N) and puncture hardness (12.20 N), indicating improved tenderness. Electronic nose PCA explained 85.4% of total variance (PC1: 59.5%; PC2: 25.9%), clearly discriminating the three treatments. Color measurements showed that frying induced the greatest total color difference (ΔE > 1, p < 0.05), followed by roasting and boiling. FTIR analysis revealed pronounced shifts in amide I bands in fried samples, indicating stronger protein secondary structure alterations. Overall, different thermal processing methods produced distinct quality and flavor characteristics in pigeon meat, providing scientific guidance for process optimization and product development. Full article

(This article belongs to the Special Issue Aroma and Volatile Compounds from Foods)

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17 pages, 624 KB

Open AccessArticle

Aroma Profile of Worts and Contents of Selected Mineral Elements in Brewing with Malted and Unmalted Hemp Seeds

by Robert Duliński, Marek Zdaniewicz, Jana Lakatošová, Adam Florkiewicz, Janusz Gołaszewski and Bożena Bukowska

Molecules 2026, 31(5), 809; https://doi.org/10.3390/molecules31050809 (registering DOI) - 28 Feb 2026

Abstract

The growing interest in functional beer production has led to the exploration of unconventional raw materials, such as hemp (Cannabis sativa L.), for brewing applications. This study aimed to evaluate the volatile organic compound (VOC) profile and the macro- and microelement composition [...] Read more.

The growing interest in functional beer production has led to the exploration of unconventional raw materials, such as hemp (Cannabis sativa L.), for brewing applications. This study aimed to evaluate the volatile organic compound (VOC) profile and the macro- and microelement composition of barley wort enriched with varying proportions (10% and 30%) of malted and unmalted hemp seeds, using solid-phase microextraction followed by gas chromatography–mass spectrometry (SPME–GC–MS) and atomic absorption spectrometry (AAS). A total of 64 VOCs were identified across four wort variants: control (barley malt only), 10% malted hemp, 30% malted hemp, and 30% unmalted hemp. The aroma profile was significantly influenced by compounds such as 2,3-butanediol, 1-hexanol, 3-methyl-1-butanol, 3-hydroxy-2-butanone, hexanoic acid, and 4-vinylguaiacol (p < 0.001). Principal component analysis (PCA) revealed clear separation between wort types based on the relative abundance of alcohols, acids, ketones, and phenols, indicating a progressive shift from sweet/malty toward acidic, green, and herbal aroma notes as hemp addition increased. Notably, unmalted hemp seeds resulted in a pronounced dominance of hexanoic acid, which may contribute to earthy and rancid sensory attributes. The evaluation of selected mineral elements showed that the key macroelements differentiating the worts were potassium, magnesium, phosphorus, and calcium, while among the microelements the distinguishing elements were manganese, iron, and sodium. These findings demonstrate the strong modulating effect of aromatic hemp-derived materials on the aroma composition and selected mineral content of brewing worts, supporting their targeted use in novel beer formulations. Full article

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4 pages, 145 KB

Open AccessEditorial

Recent Advances in Development of Small Molecules to Fight Cancer—Second Edition

by Giulia Bononi and Carlotta Granchi

Molecules 2026, 31(5), 808; https://doi.org/10.3390/molecules31050808 (registering DOI) - 28 Feb 2026

Abstract

Cancer drug discovery continues to rely on the development of small molecules able to modulate key biological processes involved in tumor initiation and progression [...] Full article

(This article belongs to the Special Issue Recent Advances in Development of Small Molecules to Fight Cancer—2nd Edition)

19 pages, 14411 KB

Open AccessFeature PaperArticle

Integrative Mechanistic Investigation of the Anticancer Effects of Panax notoginseng in Colorectal Cancer

by Jaemoo Chun, Sarah Shin and Jeeyoun Jung

Molecules 2026, 31(5), 807; https://doi.org/10.3390/molecules31050807 (registering DOI) - 28 Feb 2026

Abstract

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality worldwide, necessitating the development of novel multi-targeted therapeutic agents. This study investigates the anticancer effects of Panax notoginseng extract (PNE) against CRC using an integrative approach of network pharmacology and experimental validation. Phytochemical [...] Read more.

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality worldwide, necessitating the development of novel multi-targeted therapeutic agents. This study investigates the anticancer effects of Panax notoginseng extract (PNE) against CRC using an integrative approach of network pharmacology and experimental validation. Phytochemical profiling via LC–MS identified major ginsenosides, including Rb1, Rg1, and Rd. Network pharmacology analysis revealed potential targets such as Bcl-xL, STAT3/CDK1, and IL-2, which are associated with apoptosis, cell cycle regulation, and immune modulation, respectively. Experimental results demonstrated that PNE significantly inhibited the proliferation of HCT 116 and HT-29 CRC cells, induced G0/G1 phase arrest by modulating CDK4/6 and p21/p27, and promoted apoptosis by regulating BCL2 family proteins. Furthermore, PNE treatment suppressed tumor growth in a CT26-bearing syngeneic mouse model. These findings highlight that PNE exerts potent anticancer effects through multi-pathway modulation, suggesting its potential as a therapeutic candidate for CRC. Full article

(This article belongs to the Special Issue Probing Pharmacological and Biological Performance of Synthetic and Natural Compounds—2nd Edition)

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3 pages, 4467 KB

Open AccessCorrection

Correction: Zhang et al. Protopine Protects Mice Against LPS-Induced Acute Kidney Injury by Inhibiting Apoptosis and Inflammation via the TLR4 Signaling Pathway. Molecules 2020, 25, 15

by Beibei Zhang, Mengnan Zeng, Meng Li, Yuxuan Kan, Benke Li, Ruiqi Xu, Yuanyuan Wu, Shengchao Wang, Xiaoke Zheng and Weisheng Feng

Molecules 2026, 31(5), 806; https://doi.org/10.3390/molecules31050806 (registering DOI) - 28 Feb 2026

Abstract

In the original publication [...] Full article

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12 pages, 680 KB

Open AccessArticle

Quantitative Analysis of Bisphenol A in Commercial Beverages

by Ana I. Freitas, Marta S. Ferreira and José C. Marques

Molecules 2026, 31(5), 805; https://doi.org/10.3390/molecules31050805 (registering DOI) - 28 Feb 2026

Abstract

Bisphenol A (BPA) is a widely used synthetic compound and a well-known endocrine-disrupting chemical that has been linked to a range of health issues and poses significant public health concern. Despite efforts to regulate its use in food-contact materials, BPA remains a significant [...] Read more.

Bisphenol A (BPA) is a widely used synthetic compound and a well-known endocrine-disrupting chemical that has been linked to a range of health issues and poses significant public health concern. Despite efforts to regulate its use in food-contact materials, BPA remains a significant food contaminant due to its widespread use and its ability to leach into consumer products. Therefore, it is paramount to continue monitoring this contaminant in the food supply chain. This work aims to assess human exposure by investigating the presence of BPA in beverages, including iced teas, fruit juices, water, and carbonated drinks. The analysis by liquid chromatography coupled with fluorescence detection reveals BPA above the limit of quantification in about 30% of samples, with concentrations ranging from 0.15 to 0.94 ng/mL. The highest detection frequencies are observed in iced teas and canned beverages, while water and glass-bottled drinks have the lowest BPA detection frequencies. In the future, we aim to use the results from this study as a reference to optimize a chitosan-coated optical fiber sensor as a possible alternative for rapid BPA detection. A preliminary test showed that the sensor can discriminate between BPA concentrations of 10–100 µg/mL in a real food matrix. Full article

(This article belongs to the Special Issue Application of Analytical Chemistry in Food Science)

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21 pages, 4359 KB

Open AccessArticle

Cytokinin-Regulated Enhancement of Antioxidant Phenolic Compound Accumulation in Clerodendrum spp. In Vitro Cultures

by Jan Gomulski, Martyna Kinalska, Joanna Sodel and Izabela Grzegorczyk-Karolak

Molecules 2026, 31(5), 804; https://doi.org/10.3390/molecules31050804 - 27 Feb 2026

Abstract

This study examined shoot proliferation and phenolic compounds accumulation in Clerodendrum colebrookianum and Clerodendrum trichotomum in vitro culture. The cultures were treated with 6-benzylaminopurine (BAP), meta-topolin (M-T), or N-benzyl-9-(2-tetrahydropyranyl)adenine (BPA) (0.5, 1.0 and 2.0 mg/L), and their biomass accumulation, shoot proliferation, and phenolic [...] Read more.

This study examined shoot proliferation and phenolic compounds accumulation in Clerodendrum colebrookianum and Clerodendrum trichotomum in vitro culture. The cultures were treated with 6-benzylaminopurine (BAP), meta-topolin (M-T), or N-benzyl-9-(2-tetrahydropyranyl)adenine (BPA) (0.5, 1.0 and 2.0 mg/L), and their biomass accumulation, shoot proliferation, and phenolic profiles were quantitatively assessed. In C. colebrookianum, BPA and M-T at 0.5 and 1.0 mg/L yielded higher proliferation rates (11.0–12.0 shoots per explant) and biomass production than BAP. In C. trichotomum, maximal shoot multiplication was achieved with 2.0 mg/L M-T (24.47 shoots per explant), and peak biomass accumulation was achieved with 1.0 mg/L BPA. The two species demonstrated polyphenolic fingerprints, with C. colebrookianum extract containing seven polyphenols and C. trichotomum ten, predominantly represented by acteoside and related compounds. M-T treatments markedly enhanced phenolic biosynthesis, yielding a 3.3-fold increase in acteoside in C. colebrookianum (82.73 mg/g DW) at 2.0 mg/L and in C. trichotomum (41.3 mg/g DW) at 1.0 mg/L relative to controls. TOPSIS multi-criteria decision analysis, integrating growth parameters, acteoside, and total phenolic content, found the optimal supplementation to be 1.0 mg/L M-T in the presence of 0.1 mg/L IAA for both species (closeness coefficients: 0.821 and 0.792, respectively). The extracts derived from optimized cultures exhibited significant radical-scavenging and metal reduction capacity in DPPH, ABTS, FRAP, and CUPRAC assays; a stronger effect was observed for C. colebrookianum, which may be associated with acteoside enrichment. Overall, M-T and BPA were found to be superior to BAP in promoting biomass accumulation and high-value bioactive phenolic production in Clerodendrum spp. Our findings underscore the potential of in vitro culture systems as a sustainable source of antioxidant phytochemicals with prospective nutraceutical and pharmaceutical relevance. Full article

(This article belongs to the Special Issue Phytochemical Profiling, Bioactivity, Biotechnology Studies and Practical Applications of Medicinal and Cosmetic Plants)

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38 pages, 1697 KB

Open AccessReview

Conjugated Nitroolefins as Twofold Electrophiles for the Assembly of Five-Membered Monoheterocycles via MIRC [3+2] Annulation: An Update on Synthetic and Mechanistic Aspects

by Lara Bianchi, Massimo Maccagno, Giovanni Petrillo and Cinzia Tavani

Molecules 2026, 31(5), 803; https://doi.org/10.3390/molecules31050803 - 27 Feb 2026

Abstract

Five-membered monoheterocycles, either isolated or embedded in more complex systems, are ubiquitous structural motifs in nature and hence privileged targets of synthetic chemistry. Among a plethora of methodologies used for their assembly, [3+2] annulation strategies keep attracting particular interest among chemists, partly because [...] Read more.

Five-membered monoheterocycles, either isolated or embedded in more complex systems, are ubiquitous structural motifs in nature and hence privileged targets of synthetic chemistry. Among a plethora of methodologies used for their assembly, [3+2] annulation strategies keep attracting particular interest among chemists, partly because of some significant characteristics from both the operative and the environmental viewpoints. Herein, the extensive use of conjugated nitroolefins as twofold electrophilic, two-carbon components of [3+2] MIRC (Michael-Initiated Ring Closure) annulations is reviewed as a practical and mechanistic update covering the last decade (2015–2025). Full article

(This article belongs to the Special Issue Synthesis, Properties and Application of Five- and Six-Membered Heterocycles)

22 pages, 1196 KB

Open AccessArticle

Polyphenolic and Mineral Composition of Functional Foods Based on Rape Honey and Dried Fruits

by Elisabeta-Irina Geană, Claudia Sandru, Cornelia Carmen Abalaru, Mihaiela Cornea-Cipcigan and Rodica Margaoan

Molecules 2026, 31(5), 802; https://doi.org/10.3390/molecules31050802 - 27 Feb 2026

Abstract

Honey’s medicinal properties are largely attributed to its antioxidant activity, mainly derived from flavonoids, phenolic acids, and their derivatives. Fruit berries, such as goji berries, sea buckthorn, and black currant, are particularly rich in vitamins, phenolic compounds, and minerals, providing high nutritional and [...] Read more.

Honey’s medicinal properties are largely attributed to its antioxidant activity, mainly derived from flavonoids, phenolic acids, and their derivatives. Fruit berries, such as goji berries, sea buckthorn, and black currant, are particularly rich in vitamins, phenolic compounds, and minerals, providing high nutritional and pharmacological value. Enrichment of rapeseed honey with dried fruits significantly increased total phenolic content, with the highest value observed in honey containing goji berries (111.221 ± 20.551 mg GAE/100 g), followed by black currant (96.477 ± 31.053 mg GAE/100 g) and sea buckthorn (90.724 ± 19.72 mg GAE/100 g), compared to control honey (49.681 ± 14.44 mg GAE/100 g). Antioxidant activity, assessed by multiple assays, was markedly enhanced in functional foods based on rape honey and dried fruits, particularly those with black currant, followed by goji berries and sea buckthorn. Romanian rapeseed honey contained phenolic acids such as gallic, chlorogenic, 4-hydroxybenzoic, and 3,4-dihydroxybenzoic acids, and flavonoids including quercetin and naringin. Functional food based on rape honey and goji berries (GBH) showed the highest levels of chlorogenic and gallic acids, epicatechin, and rutin, while functional food based on rape honey and sea buckthorn (SBH) was rich in naringin and resveratrol. Functional food based on rape honey and black currant (BCH) exhibited elevated gallic acid and rutin. Potassium and magnesium were the predominant minerals in all samples. Overall, berry enrichment enhances the nutritional and antioxidant profile of honey, supporting immune function and general health. Full article

(This article belongs to the Special Issue Biological Activity and Chemical Composition of Honeybee Products)

38 pages, 1888 KB

Open AccessReview

Current State of Knowledge of the Anticancer Properties of Polyphenolic Compounds from Garlic (Allium sativum L.)

by Urszula Binduga and Konrad A. Szychowski

Molecules 2026, 31(5), 801; https://doi.org/10.3390/molecules31050801 - 27 Feb 2026

Abstract

Garlic (Allium sativum L.) belongs to the Allium genus and is one of the main bulbous plants consumed fresh, powdered, or cooked. Numerous studies have shown that garlic exhibits antihyperlipidaemic, antioxidant, anti-inflammatory, cardiovascular disease preventive, antihypertensive, antibacterial, antiviral, antifungal, antiparasitic, antidiabetic, anticarcinogenic, [...] Read more.

Garlic (Allium sativum L.) belongs to the Allium genus and is one of the main bulbous plants consumed fresh, powdered, or cooked. Numerous studies have shown that garlic exhibits antihyperlipidaemic, antioxidant, anti-inflammatory, cardiovascular disease preventive, antihypertensive, antibacterial, antiviral, antifungal, antiparasitic, antidiabetic, anticarcinogenic, hepatoprotective, immunomodulatory, and hypoglycaemic effects. Moreover, studies on polyphenols detected in garlic reveal strong anticancer properties in various cell lines. The aim of this review is to summarise the current state of knowledge regarding the anticancer properties and shared molecular mechanisms of action of garlic-derived polyphenolic compounds. Our analysis demonstrates that the polyphenol content in garlic is highly variable and depends on numerous factors, including the part of the plant, processing methods, place of cultivation, and other conditions. Additionally, garlic contains polyphenols that exhibit anticancer activity in preclinical models, the properties of which have been demonstrated in in vitro studies. The anticancer mechanism of action varies depending on the type of polyphenol. Several polyphenols from garlic such as e.g., catechin, quercetin, and kaempferol activate peroxisome proliferator-activated receptors, which appear to contribute to at least part of garlic’s anticancer activity. The primary mechanism of garlic’s anticancer properties relies on reactive oxygen species-dependent toxicity and/or apoptosis, and Nrf2 is also implicated in the mechanism of action of garlic polyphenols. Our review provides evidence that under in vitro conditions, polyphenols present in garlic may exhibit anticancer properties. Garlic is not only a valuable culinary ingredient but also a natural medicine. Regular consumption in moderate amounts may offer numerous health benefits. Full article

(This article belongs to the Special Issue Antioxidant, and Anti-Inflammatory Activities of Natural Plants)

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22 pages, 1384 KB

Open AccessArticle

The Application of Manganese Complexes with Some Tetraazamacrocycles Immobilized in a Nafion Layer on a Glassy Carbon Electrode in Anodic Heterogenic Electrocatalysis

by Danuta Tomczyk and Piotr Seliger

Molecules 2026, 31(5), 800; https://doi.org/10.3390/molecules31050800 - 27 Feb 2026

Abstract

Modified electrodes were obtained by immobilizing Mn³⁺ complexes with the following tetraazamacrocycles (1,4,7,10-tetraazacyclododecane ([12]aneN₄), 1,4,8,11-tetrazacyclotetradecane ([14]aneN₄), 1,4,7,11-tetrazacyclotetradecane (iso[14]aneN₄), and 1,4,8,12-tetrazacyclopentadecane ([15]aneN₄) in a Nafion film on the surface of a glassy carbon [...] Read more.

Modified electrodes were obtained by immobilizing Mn³⁺ complexes with the following tetraazamacrocycles (1,4,7,10-tetraazacyclododecane ([12]aneN₄), 1,4,8,11-tetrazacyclotetradecane ([14]aneN₄), 1,4,7,11-tetrazacyclotetradecane (iso[14]aneN₄), and 1,4,8,12-tetrazacyclopentadecane ([15]aneN₄) in a Nafion film on the surface of a glassy carbon electrode (GCE). Based on spectroelectrochemical, chronopotentiometric, and chronoamperometric studies, oxidation of mononuclear complexes to dinuclear di-μ-oxo complexes of Mn³⁺ and Mn⁴⁺ was observed, and the mechanism and influence of Nafion on this process were determined. On the basis of voltammetric and chronocoulometric studies, the electroactivity, stability, and diffusion rates of such modified electrodes were demonstrated. Based on voltammetric and chronocoulometric studies, their electrocatalytic properties were analyzed in relation to the oxidation of model compounds used in this type of research, namely, ascorbic acid, glycolaldehyde, and glycolic acid. Full article

(This article belongs to the Special Issue Ligands: Design, Syntheses, and Applications in Organometallic Catalysis)

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15 pages, 2193 KB

Open AccessArticle

Rapid Analysis of Phytic Acid by Paper Spray Mass Spectrometry

by Ping Guo, Sijie Zhu and Bo Chen

Molecules 2026, 31(5), 799; https://doi.org/10.3390/molecules31050799 - 27 Feb 2026

Abstract

Phytic acid (PA), owing to its strong acidity and multidentate metal-chelating properties, readily forms multiple adduct/complex ions in mass spectrometry and is prone to pronounced matrix effects, resulting in complicated spectra and compromised sensitivity and quantitative robustness, which poses a major challenge for [...] Read more.

Phytic acid (PA), owing to its strong acidity and multidentate metal-chelating properties, readily forms multiple adduct/complex ions in mass spectrometry and is prone to pronounced matrix effects, resulting in complicated spectra and compromised sensitivity and quantitative robustness, which poses a major challenge for rapid and accurate PA quantification. Herein, we developed a rapid quantitative method for PA based on trimethylsilyldiazomethane (TMSD) methyl-ester derivatization coupled with paper spray mass spectrometry (PS–MS). PA was derivatized with TMSD to yield the methylated product (PA-Me), and the derivative solution was purified via “post-derivatization nitrogen blow-down followed by water reconstitution”, thereby markedly reducing background interference. In positive-ion mode, the stable sodium adduct ion [PA-Me+Na]⁺ (m/z 851.04) was used as the quantifier, enabling fast quantification with selected ion monitoring (SIM). PS–MS was performed with a 15 μL spotting volume and methanol/water (90/10, v/v, containing 0.1% formic acid) as the spray solvent, allowing rapid analysis without chromatographic separation. The method exhibited good linearity over 0.125–30 μg/mL (R² ≥ 0.9965), with a limit of detection (LOD, S/N = 3) of 0.080 μg/mL and a limit of quantification (LOQ, S/N = 10) of 0.270 μg/mL. The intra-day and inter-day precision values were both < 10% (RSD), and recoveries ranged from 87.2% to 122.4%. This LC-free strategy features low solvent consumption and high analytical throughput, and was validated using rice bran protein and rice bran polysaccharide samples, providing technical support for rapid screening and quality control of PA in complex food/plant matrices. Full article

(This article belongs to the Special Issue Advanced Analytical Methods in Food Chemistry)

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32 pages, 1777 KB

Open AccessReview

Beyond Removal: A Critical Review of Microplastic Mass Flux, In-Plant Transformation, and Elimination in WWTPs

by Niu Imeleta Faauma, Ying Guo, Wenxin Li, Wei Wen and Bo Jiang

Molecules 2026, 31(5), 798; https://doi.org/10.3390/molecules31050798 - 27 Feb 2026

Abstract

Microplastics (MPs) persist in wastewater treatment systems owing to their durability and mobility. As critical interception points, wastewater treatment plants (WWTPs) receive MPs from diverse domestic and industrial sources. This review synthesizes peer-reviewed studies (2009–2026) to evaluate MP mass flux, in-plant transformation, and [...] Read more.

Microplastics (MPs) persist in wastewater treatment systems owing to their durability and mobility. As critical interception points, wastewater treatment plants (WWTPs) receive MPs from diverse domestic and industrial sources. This review synthesizes peer-reviewed studies (2009–2026) to evaluate MP mass flux, in-plant transformation, and elimination across primary, secondary, and tertiary stages. While conventional processes typically remove 60–90% of MPs, advanced tertiary technologies, such as membrane bioreactors and rapid sand filtration, can achieve efficiencies exceeding 95%. The fate of MPs is governed by density-driven settling and biological aggregation; however, the significant accumulation of MPs in sewage sludge represents a critical pathway for environmental re-entry. This review highlights key knowledge gaps, including inconsistent analytical methodologies, evidence of in-plant fragmentation generating nanoplastics (NPs), and uncertainties regarding full-scale mass flows. Furthermore, the review synthesizes mass flux data to clarify the partitioning of MPs between the effluent and sludge, identifying biosolids as a primary sink. The review concludes by proposing a transition from physical separation to elimination technologies (e.g., AOPs), alongside standardized monitoring and regulatory frameworks, to achieve sustainable reductions in MP emissions. Full article

(This article belongs to the Special Issue Solid Waste and Fly Ash Chemical Treatment Methods—2nd Edition)

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31 pages, 5472 KB

Open AccessArticle

Green Synthesis of Bergamot Solid Waste-Based Silver Nanoparticles: Optimization Process for Agriculture Use

by Roberta Caridi, Maria Rosa Abenavoli, Licia Elvira Prestagiacomo, Marco Gaspari, Antonio Mauceri, Meriem Miyassa Aci, Isidoro Giorgio Lesci and Agostino Sorgonà

Molecules 2026, 31(5), 797; https://doi.org/10.3390/molecules31050797 - 27 Feb 2026

Abstract

Green-synthesized metal nanoparticles are increasingly investigated for their antioxidative, antimicrobial, and stress-protective properties as eco-friendly and cost-effective alternatives to conventional chemical synthesis. Although agri-food wastes represent biomolecule-rich and sustainable resources, they remain less explored as biological matrices for green metal nanoparticle synthesis compared [...] Read more.

Green-synthesized metal nanoparticles are increasingly investigated for their antioxidative, antimicrobial, and stress-protective properties as eco-friendly and cost-effective alternatives to conventional chemical synthesis. Although agri-food wastes represent biomolecule-rich and sustainable resources, they remain less explored as biological matrices for green metal nanoparticle synthesis compared with plant and microbial extracts. The aim of this study was to optimize the synthesis and evaluate the bioactivity of silver nanoparticles derived from bergamot pomace, a polyphenol-rich agri-food waste. Synthesis parameters, including extract concentration, pH, extract-to-metal ratio, temperature, and reaction time, were optimized, and the nanoparticles were characterized by UV–Vis spectroscopy, dynamic light scattering, zeta potential analysis, and electron microscopy (TEM, STEM). ATR-FTIR and proteomic analyses were employed to investigate the molecular mechanisms involved in nanoparticle reduction, capping, and stabilization. The bergamot pomace-based silver nanoparticles exhibited a surface plasmon resonance peak at 430 nm, spherical morphology, good colloidal stability, and average diameters of 15–20 nm, without irreversible aggregation. A putative synthesis mechanism was proposed, involving Ag⁺ bioreduction mediated by polyphenols, ascorbic acid, and oxidoreductase-associated proteins, followed by stabilization through protein corona formation. Seed nanopriming assays on tomato and lettuce, together with in vitro antimicrobial tests against Pseudomonas syringae pv. tomato and Xanthomonas campestris pv. vesicatoria, demonstrated phytostimulatory and antimicrobial effects at very low nanoparticle concentrations. Overall, this study highlights bergamot pomace as a valuable resource for green silver nanoparticle synthesis, supporting its applicability in sustainable agriculture. Full article

(This article belongs to the Special Issue Natural Products as Plant Protection Agents)

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18 pages, 3541 KB

Open AccessArticle

Structural Elucidation of Azo and Quinoneimine Products Formed in Diazonium-Based Color Reactions of Cannabinoids

by Hikari Nishiguchi, Kayo Nakamura, Ryosuke Arai, Riho Hamajima, Hiroko Abe, Akihiko Ishida, Manabu Tokeshi, Kyohei Higashi, Akiyoshi Saitoh and Hideyo Takahashi

Molecules 2026, 31(5), 796; https://doi.org/10.3390/molecules31050796 - 27 Feb 2026

Abstract

Cannabis use is generally restricted worldwide because it contains the narcotic compound Δ⁹-tetrahydrocannabinol (Δ⁹-THC). Although cannabis is detected at crime scenes using color-based primary screening methods, the details of the reaction mechanism have not yet been elucidated. In this [...] Read more.

Cannabis use is generally restricted worldwide because it contains the narcotic compound Δ⁹-tetrahydrocannabinol (Δ⁹-THC). Although cannabis is detected at crime scenes using color-based primary screening methods, the details of the reaction mechanism have not yet been elucidated. In this study, we isolated the products generated during the color reaction between the diazonium salt prepared from para-nitroaniline and nine cannabinoids and determined their structures. Azo compounds 6, 11, 16, and 17 were produced from cannabidiol, cannabigerol, cannabichromene, and cannabidiolic acid, respectively, while quinoneimines 7–10 and 12–15, which contained positional isomers, were produced from cannabinol, Δ⁹-THC, and hexahydrocannabinol. The reaction barely proceeded with Δ⁹-THC acetate and HHC acetate. Full article

(This article belongs to the Section Organic Chemistry)

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4 pages, 142 KB

Open AccessEditorial

Advanced Magnetic Resonance Methods in Materials Chemistry Analysis

by Igor Serša

Molecules 2026, 31(5), 795; https://doi.org/10.3390/molecules31050795 - 27 Feb 2026

Abstract

For decades, magnetic resonance has been considered one of the most insightful and versatile families of analytical techniques available to chemists, physicists, and materials scientists [...] Full article

(This article belongs to the Special Issue Advanced Magnetic Resonance Methods in Materials Chemistry Analysis)

15 pages, 2885 KB

Open AccessArticle

Photocatalytic Degradation of an Aromatic Pharmaceutical over TiO₂: Experimental and Computational Insights into Inhibition Effects of Natural Organic Acids

by Andrijana Bilić, Sanja J. Armaković and Stevan Armaković

Molecules 2026, 31(5), 794; https://doi.org/10.3390/molecules31050794 - 27 Feb 2026

Abstract

The photocatalytic degradation of the pharmaceutical compound nadolol over TiO₂ under UV-LED irradiation was investigated, with particular emphasis on the inhibitory effects of common low-molecular-weight organic acids. Due to its aromatic (tetralin-like) motif and multiple heteroatom-containing functional groups, nadolol serves as a [...] Read more.

The photocatalytic degradation of the pharmaceutical compound nadolol over TiO₂ under UV-LED irradiation was investigated, with particular emphasis on the inhibitory effects of common low-molecular-weight organic acids. Due to its aromatic (tetralin-like) motif and multiple heteroatom-containing functional groups, nadolol serves as a representative model for aromatic micropollutants whose fate can be governed by surface competition and noncovalent interactions. While TiO₂ showed high photocatalytic activity in ultrapure water, achieving complete nadolol degradation within 120 min, the presence of citric, oxalic, and acetic acids markedly reduced the degradation efficiency by approximately 72%, 62%, and 29%, respectively. Experimental results demonstrated that this inhibition could not be attributed solely to pH changes, indicating the contribution of additional molecular-level effects. To elucidate the underlying mechanism, molecular and periodic density functional theory (DFT) calculations were performed. The computational analysis revealed strong interactions between nadolol, organic acids, and the TiO₂ surface, leading to competitive adsorption and partial blocking of photocatalytically active sites. These results provide mechanistic insight into the role of natural organic acids in TiO₂-based photocatalytic systems and highlight the importance of considering real-water matrix components when designing efficient and sustainable photocatalytic water treatment processes. Full article

(This article belongs to the Special Issue Synthesis, Crystal Structure, and Application of Schiff Base Complexes)

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53 pages, 5252 KB

Open AccessReview

Enhanced Bioavailability and Health Benefits of Blueberry Anthocyanins: An Updated Review on Mechanisms and Approaches

by Rabia Ramzan, Zafarullah Muhammad, Adnan Amjad, Hafiz Rizwan Sharif, Guoqiang Zhang and Ana Chen

Molecules 2026, 31(5), 793; https://doi.org/10.3390/molecules31050793 - 27 Feb 2026

Abstract

Blueberries are highly valued for their nutritional content, primarily due to their high anthocyanin content, which is the principal bioactive compound contributing to their health-enhancing properties. Extensive research has established that blueberry anthocyanins exhibit significant antioxidant activity and confer various health benefits, including [...] Read more.

Blueberries are highly valued for their nutritional content, primarily due to their high anthocyanin content, which is the principal bioactive compound contributing to their health-enhancing properties. Extensive research has established that blueberry anthocyanins exhibit significant antioxidant activity and confer various health benefits, including anti-cardiovascular, anti-diabetic, anti-inflammatory, and anticancer effects, as well as enhancements in cognitive function and visual acuity. Nonetheless, the chemical instability of anthocyanins, influenced by environmental factors such as temperature, light, oxygen, pH, and enzymatic activity, presents a substantial challenge for their effective application, leading to reduced stability, limited bioavailability, and decreased efficacy in functional foods and nutraceuticals. Using a defined search strategy focused on recent advances, this review synthesizes the chemical structures, biological activities, and health benefits of blueberry anthocyanins and critically examines strategies to improve their stability and bioavailability, including nanoparticulate systems, microencapsulation, based on delivery systems like protein, polysaccharides, liposomes, multiple emulsions, and composite delivery systems. Additionally, this review underscores the current research status and translational prospects for the industrial application of blueberry anthocyanins while also considering key scalability issues, including carrier regulation, sensory effects, and shelf-life stability. Developing practical approaches to enhance anthocyanin stability and bioavailability is crucial for maximizing their therapeutic potential and advancing the use of blueberries as functional foods. Full article

(This article belongs to the Special Issue Exploring the Antioxidant Activity of Natural Extracts: New Findings and Potential Food- and Non-Food-Related Applications)

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