Search Results (845)

Perezone, a sesquiterpene quinone, was the first natural product isolated in crystalline form on the American continent in 1852. It is commonly found in the roots of herbs from the Acourtia species (formerly Perezia). This molecule, along with its synthetic isomer isoperezone, exhibits antineoplastic effects, among others. In this study, an enzymatic reaction (green chemistry) was employed to oxidize the C12−C13 double bond of perezone and isoperezone. This method proved to be more effective than traditional toxic chemical oxidants. As result, epoxides were obtained, followed by acetonides, diols, and esters. All compounds were successfully synthesized and characterized using standard spectroscopic techniques. In breast cancer cell tests, the isoperezone acetonide showed the highest cytotoxicity, with an IC₅₀ of 8.44 µM. Additionally, a computational study was performed at the DFT (B3LYP) level of theory, indicating that the geometrical and energy differences between 6-R and 6-S stereoisomers are 0.5 kcal/mol, and the spectroscopic and electronic properties aligned with the experimental data. Finally, molecular docking revealed binding energies of −8.14 kcal/mol for 6-R and −8.04 kcal/mol for 6-S, with a hydrogen bond of 2.9 Å involving the His121 residue. A chemoinformatic prediction was also conducted to compare cytotoxicity results. Full article

In the Yucatán Peninsula, Citrus aurantium L. has a strong cultural and culinary relevance where local industries already process its juice and essential oils, producing large amounts of by-products. In this context, green chemistry strategies have accelerated the valorization of agro-industrial residues, where Natural Deep Eutectic Solvents (NADESs) stand out due to their low cost, ease of preparation, and high extraction efficiency. This study focuses on evaluating different NADES combinations for the extraction of bioactive compounds from C. aurantium by-products, obtained after essential oil (cold pressing) and juice (mechanical pressing) extraction. A 3 × 2 × 2 factorial design was implemented to evaluate the effect of hydrogen bond donor (HBD: fructose, glucose and glycerol), molar ratio (MR: 1:1 and 1:2 mol/mol choline chloride (ChCl:HBD)) and added water (AW: 50 and 70%) on the polyphenolic profile, total phenolic content, total flavonoid content, ascorbic acid content and antioxidant capacity. HBD was the most critical factor in the extraction of bioactive compounds; the extract obtained with glycerol and 70% AW exhibited the highest hesperidin content (2186.08 mg/100 g dry mass), while the same HBD with 50% AW exhibited the highest quercetin + luteolin extraction (721.32 mg/100 g dry mass), both at the same MR (1:1 mol/mol). Glycerol also achieved the highest recovery of total flavonoids (1829.7 ± 17.85 mg quercetin equivalent/100 g dry mass) with an MR of 1:2 mol/mol and 70% AW. Finally, all other maximum values were obtained with fructose-based NADESs: the highest total phenolic content (3603. 7 ± 52.9 mg gallic acid equivalent/100 g dry mass) was achieved at an MR of 1:1 mol/mol and 50% AW, while for both vitamin C (1964.8 ± 33.7 mg ascorbic acid equivalent/100 g dry mass) and antioxidant capacity (84.31% inhibition), the maximum was reached at an MR of 1:2 mol/mol and 50% AW. Full article

Agri-food residues have accumulated globally at unprecedented scales, generating environmental pressures and resource inefficiencies, a core problem addressed in this review, while simultaneously representing rich, underutilized reservoirs of health-promoting phytochemicals. This review synthesizes recent advances (2016–2025) in the green extraction, characterization, and biological validation of phytochemicals from plant-based residues, including polyphenols, flavonoids, carotenoids, alkaloids, and dietary fibers from key sources such as grape pomace, citrus peels, coffee silverskin, pomegranate peel, cereal brans, and tropical fruit by-products. Emphasis is placed on sustainable extraction methods: ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), pressurized liquid extraction (PLE), supercritical CO₂ extraction (SFE), and natural deep eutectic solvents (NADES), which enable efficient recovery while minimizing environmental impact. In vitro, in vivo, and clinical studies demonstrate that residue-derived compounds exert antioxidant, anti-inflammatory, metabolic-regulating, and prebiotic effects, contributing to health in general and gut microbiota modulation. Integrating these bioactives into functional foods and nutraceuticals supports sustainable nutrition and circular bioeconomy goals by reducing food waste and promoting health-oriented valorization. Regulatory advances, including approvals from the European Food Safety Authority (EFSA) and the U.S. Food and Drug Administration (FDA) for ingredients such as olive phenolics, citrus flavanones, and coffee cascara, further illustrate increasing translational readiness. The convergence of green chemistry, biorefinery design, and nutritional science positions agri-food residues as pivotal resources for future health-promoting and environmentally responsible diets. Remaining challenges include scaling cost-effective green processes, harmonizing life cycle assessment protocols, expanding toxicological datasets, and conducting longer-term clinical trials to support safe and evidence-based commercialization. Full article

Fabaceae family is recognized as a prolific flavonoid producer, including some unusual flavonoid skeletons. Although classic flavonoids have well-established biological properties in the literature, these unusual compounds remain underinvestigated. Based on that, the current study sought to explore the chemistry and biological activity of rare flavonoids in Fabaceae with a review comprising their occurrence, extraction, isolation and pharmacological potential. Additionally, the use of LC-MS applied to the study of seven subclasses (aurones, biflavonoids, coumestans, homoisoflavonoids, neoflavonoids, pterocarpans, and rotenoids) is also discussed. The review was carried out by searching for specified uniterms on SciFinder and Web of Science, covering the last ten years. In addition, to assess ADMET and drug-like properties by in silico predictions, all the substances considered in this work were compiled and organized into a curated dataset. As a result, a total of 170 flavonoid structures were included, most of which were found in the roots and leaves. In addition, a wide range of biological activities were observed, such as cytotoxic, antiviral and anti-inflammatory. Despite advancements in the use of LC-MS for bioprospection, just a few reports dedicated to the study of these compounds were found. Regarding ADMET profiles, most subclasses showed favorable bioavailability characteristics, with biflavonoids being the main exception. Together, this review highlights the significance of unusual flavonoids from the Fabaceae family, demonstrating their remarkable chemical diversity and largely, but still, unexplored pharmacological potential. These findings encourage further investigations, particularly in the fields of natural products chemistry, medicinal chemistry, and pharmacology. Full article

Isocyanide-based multicomponent reactions, such as the Ugi four-component reaction, are among the most relevant synthetic tools in modern organic chemistry. They have been successfully applied in natural product science for the synthesis of natural product analogs, for example, carbohydrates and steroids. However, the synthesis of analogs of other important groups, like triterpenoids, remains rarely studied. In the present work, we report the synthesis of four bis-amides via the Ugi reaction starting from masticadienonic acid, a triterpenoid isolated from Pistacia mexicana. Full article

1,5-disubstituted tetrazoles (1,5-Ds-T) are heterocyclic bioisosteres of the cis-amide bond, commonly found in bioactive compounds, pharmaceuticals, and functional materials. Chromones are privileged scaffolds widely present in natural products that are well known for their diverse biological activities, including anticancer, antimicrobial, antidiabetic, anti-inflammatory, and antioxidant properties. Isocyanide-based multicomponent reactions, such as the Ugi-Azide (UA-4CR), provide a versatile strategy for synthesizing 1,5-Ds-T, which can be incorporated into other privileged heterocyclic or commercially available drugs. Herein, we describe a sonochemical one-pot synthesis of 1,5-Ds-T connected to chromone under mild conditions, highlighting their potential relevance in medicinal chemistry. Full article

To clarify the characteristics of CO₂–formation water–rock reactions in tight sandstones and their effects on CO₂-enhanced oil recovery (EOR) efficiency and storage efficiency, this study takes the tight oil reservoirs of the Changqing Jiyuan Oilfield as the research object. A variety of experimental techniques, including ICP-OES elemental analysis, powder X-ray diffraction, and scanning electron microscopy, were employed to systematically investigate the mechanisms and main influencing factors of water–rock reactions during CO₂ geological storage. The study focused on analyzing the roles of mineral composition, reservoir pore structure, and formation water chemistry in the reaction process. It explored the potential impacts of reaction products on reservoir properties. Furthermore, based on the experimental results, a coupled reservoir numerical simulation of CO₂ injection for EOR and storage was conducted to comprehensively evaluate the influence of mineralization processes on CO₂ EOR performance and long-term storage efficiency. Results show that the tight sandstone reservoirs in Jiyuan Oilfield are mainly composed of calcite, quartz, and feldspar. The dominant water–rock reactions during CO₂ formation–water interactions are calcite dissolution and feldspar dissolution. Among these, calcite dissolution is considered the controlling reaction due to its significant effect on the chemical composition of formation water, and the temporal variation in other elements shows a clear correlation with the calcite dissolution process. Further analysis reveals that water–rock reactions lead to permeability reduction in natural fractures near injection wells, thereby effectively improving CO₂ EOR efficiency, enhancing sweep volume, and increasing reservoir recovery. At the end of the EOR stage, mineralized CO₂ storage accounts for only 0.53% of the total stored CO₂. However, with the extension of time, mineralized storage gradually increases, reaching a substantial 31.08% after 500 years. The study also reveals the effects of reservoir temperature, pressure, and formation water salinity on mineralization rates, emphasizing the importance of mineral trapping for long-term CO₂ storage. These findings provide a theoretical basis and practical guidance for the joint optimization of CO₂ EOR and geological sequestration. Future research may further focus on the dynamic evolution of water–rock reactions under different geological conditions to enhance the applicability and economic viability of CO₂ storage technologies. Full article

RNAs have recently emerged as versatile therapeutic targets, broadening the scope of drug discovery beyond the conventional protein-centered paradigm. Small-molecule-induced RNA degradation has been established as a promising approach, with novel modalities such as Ribonuclease-Targeting Chimeras (RIBOTACs), bleomycin-conjugated degraders, and imidazole-based RNA degrader demonstrating strong potential. These strategies selectively eliminate disease-associated RNAs by harnessing endogenous ribonucleases, redirecting the nucleic acid-cleaving activity of natural products, or incorporating catalytic warheads. Recent studies have validated therapeutic applications across cancer, neurodegenerative disorders, and viral infections, underscoring the wide-ranging impact of this strategy. Nevertheless, key challenges remain, including the development of more potent recruiters, diversification of degradation mechanisms, optimization of linker chemistry, and overcoming pharmacokinetic limitations. With continued innovation, RNA degraders are expected to evolve into a robust therapeutic platform that expands the druggable space and enables new treatment opportunities for diseases once considered untreatable. Full article

We report the first green and diastereoselective synthesis of novel thiophene bioisosteres designed to mimic the privileged pyrrolo[3,2-c]quinoline core of martinelline alkaloids. The key step features an intramolecular 1,3-dipolar cycloaddition of in situ generated non-stabilized azomethine ylides from sarcosine, which proceeds with excellent yield and diastereoselectivity. This sustainable protocol, leveraging ultrasonic irradiation, recyclable hydrotalcite catalysts, and the green solvent cyclopentyl methyl ether (CPME), efficiently constructs the complex tricyclic framework. The structure and stereochemistry of the novel bioisostere were unambiguously confirmed by X-ray crystallography. This method offers a valuable, eco-friendly approach for diversifying natural product-inspired libraries in medicinal chemistry. Full article

Plants play critical roles as nature-based solutions to maintaining air quality and regulating biogeochemical cycles, yet the mechanisms underlying these complex systems remain poorly understood. Hydrogen peroxide (H₂O₂), a globally present atmospheric oxidant, shows well-documented diurnal variation, but no direct link to plant transpiration has previously been reported. This study aimed to determine whether plants can produce exogenous H₂O₂ through transpiration and condensation, thereby revealing a novel pathway by which plants influence proximal and potentially global atmospheric chemistry. To investigate this, we examined a natural plant system undergoing photosynthesis and transpiration; our work was inspired by recent laboratory findings where spontaneous H₂O₂ was generated during the condensation of water vapour into microdroplets in engineered systems. Condensed water collected near leaf surfaces revealed H₂O₂ concentrations of 1–5 ppm, verified using both commercial peroxide test strips and spectrophotometric titration. Importantly, H₂O₂ production occurred only under light conditions when plants were transpiring, while controls without plants or without light showed no detectable levels. A strong distance-dependence was also observed, with minimal to no H₂O₂ detected beyond 40 cm from leaves. These findings suggest that plant-driven formation of water vapour and subsequent condensation produces measurable H₂O₂, establishing a previously unrecognized mechanism with implications for air quality improvement, atmospheric oxidation processes, and climate change modelling and mitigation. Full article

Biocatalysis is fundamental to biological processes and sustainable chemical productions. Over time, the biocatalysis strategy has been widely researched. Initially, biomanufacturing and catalysis of high-value chemicals were carried out through direct immobilization and application of biocatalysts, including natural enzymes and living cells. With the evolution of green chemistry and environmental concern, hybrid photoelectro-biocatalysis (HPEB) platforms are seen as a new approach to enhance biocatalysis. This strategy greatly expands the domain of natural biocatalysis, especially for bio-based components. The selective valorization of renewable furan derivatives, such as 5-hydroxymethylfurfural (HMF) and furfural, is central to advancing biomass-based chemical production. Biocatalysis offers high chemo-, regio-, and stereo-selectivity under mild conditions compared with traditional chemical catalysis, yet it is often constrained by the costly and inefficient regeneration of redox cofactors like NAD(P)H. Photoelectrocatalysis provides a sustainable means to supply reducing equivalents using solar or electrical energy. In recent years, hybrid systems that integrate biocatalysis with photoelectrocatalysis have emerged as a promising strategy to overcome this limitation. This review focuses on recent advances in such systems, where photoelectrochemical platforms enable in situ cofactor regeneration to drive enzymatic transformations of furan-based substrates. We critically analyze representative coupling strategies, materials and device configurations, and reaction engineering approaches. Finally, we outline future directions for developing efficient, robust, and industrially viable hybrid catalytic platforms for green biomass valorization. Full article

In recent years the global market of nanomedicine has experienced incredible growth owing to the advances in the field. This translation of the technique to the biomedical industry requires the development of production methods that deliver nanomedicines with a high degree of reproducibility between batches, combined with cost and time efficiency. The use of nanoparticles in medicine usually requires their surface functionalization to improve biocompatibility in addition to providing targeting capacities and/or stimuli-responsive behavior, among other interesting skills. Microfluidic technology has revolutionized the field both in nanomedicine synthesis and in preclinical evaluation. However, microfluidic-assisted synthetic procedures commonly require high-cost methods and equipment to fabricate the microreactors. The aim of this work is to present an ultra-low-cost microfluidic platform that permits the versatile modification of nanomaterials. To prove this approach, two different model nanoparticles with different natures: soft nanoparticles (liposomes) and rigid nanoparticles (mesoporous silica) have been decorated both with small molecules and with other nanoparticles, respectively, in order to evaluate the scope of this approach. The anchoring of the covalently attached elements has been performed using click chemistry, in compliance with the principles for further transfer to the drug industry. Full article

Natural deep eutectic solvents (NaDESs) have emerged as green and sustainable alternative solvents for extracting valuable bioactive compounds from agro-industrial by-products. NaDESs are stable, soluble, and biodegradable with low melting points and a wide range of applications. These characteristics align closely with the principles of green chemistry, making NaDESs promising for use in the food industry. Recent studies demonstrate that NaDESs can effectively extract proteins, polysaccharides, polyphenols, carotenoids, alkaloids, and other bioactives from sources such as vegetable waste, cereal by-products, and fruit pomace, often performing better than traditional solvents such as methanol and ethanol. The bioactive components of these extracts may exhibit antioxidant, anti-inflammatory, antihypertensive, anticancer, or antimicrobial activity and can be used as functional ingredients, nutraceuticals, or preservatives. Furthermore, NaDES-derived extracts have been shown to have hypoglycemic effects by inhibiting enzymes involved in the metabolism of carbohydrates and reducing oxidative stress. As a result, they may find use as functional food ingredients in diabetes management. This review presents the recent research on the extraction of bioactive compounds from agro-industrial by-products using NaDESs and an evaluation of their antidiabetic potential. Full article

Public understanding of complex sustainability concepts like life cycle assessment (LCA) is crucial for promoting environmentally responsible consumption yet remains a significant educational challenge. This study introduces and evaluates Paper Goes Green, a competitive board game designed to make abstract LCA principles tangible and personally relevant. The game simulates the paper production chain, compelling players to make strategic decisions about resource allocation, production pathways (conventional vs. green), and waste management to fulfill paper orders. Through a single-group pre-test/post-test design with 85 participants (25 environmental educators and 60 public members), the game’s efficacy was assessed. Paired-sample t-tests revealed significant improvements in participants’ perceived knowledge of green chemistry/LCA (pre-game mean 2.05, post-game 3.24 on a 5-point scale, p < 0.001), pro-environmental attitudes (3.38 to 4.22, p < 0.001), and behavioral intentions toward green consumption (3.97 to 4.44, p < 0.001). These gains correspond to medium-to-large effect sizes (Cohen’s d = 0.94 for knowledge, 0.70 for attitude, 0.71 for behavior), indicating substantial practical impact. Qualitative feedback further highlighted the game’s engaging and thought-provoking nature. Notably, specific design features—such as immediate feedback, player control, and interactivity—were identified as key contributors to learning, fostering systems thinking in players. These findings suggest that Paper Goes Green is a promising educational tool for translating complex environmental science into an engaging, impactful learning experience. The game effectively bridges the gap between abstract concepts and real-world consumer choices, fostering life cycle thinking and empowering players to make greener choices in their daily lives. Full article

Thorium has emerged as a promising alternative to uranium in nuclear energy systems due to its higher natural abundance, favorable conversion to fissile ²³³U, and reduced generation of long-lived transuranic waste. This review provides a comprehensive overview of advanced techniques for thorium recovery from primary ores and secondary resources. The main mineralogical carriers—including monazite, thorianite, thorite, and cheralite as well as industrial by-products such as rare-earth processing tailings—are critically examined with respect to their occurrence and processing potential. Physical enrichment methods (gravity, magnetic, and electrostatic separation) and hydrometallurgical approaches (acidic and alkaline leaching) are analyzed in detail, highlighting their efficiencies, limitations, and environmental implications. Particular emphasis is placed on modern separation strategies such as solvent extraction with organophosphorus reagents, diglycolamides, and ionic liquids, as well as extraction chromatography, nanocomposite sorbents, ion-imprinted polymers, and electrosorption on carbon-based electrodes. These techniques demonstrate significant progress in enhancing selectivity, reducing reagent consumption, and enabling recovery from low-grade and secondary feedstocks. Environmental and radiological aspects, including waste minimization, immobilization, and regulatory frameworks, are discussed as integral components of sustainable thorium management. Finally, perspectives on hybrid technologies, digital process optimization, and economic feasibility are outlined, underscoring the need for interdisciplinary approaches that combine chemistry, materials science, and environmental engineering. Collectively, the analysis highlights the transition from conventional practices to integrated, scalable, and environmentally responsible technologies for thorium recovery. Full article