Search Results (991)

Amino alcohols are a class of compounds bearing both amino and hydroxyl groups, ubiquitous in natural products and extensively utilized as key structural motifs in pharmaceuticals and functional materials. Owing to their structural diversity, inherent chirality, and high reactivity, they exhibit significant application value in the pharmaceutical field, materials industry, and organic synthesis. Compared with chemical synthesis, which suffers from limitations such as insufficient enantioselectivity, dependence on precious metal catalysts, and environmental concerns, biosynthesis offers core advantages of high stereoselectivity, mild reaction conditions, and environmental sustainability. This review systematically delineates the diverse applications of amino alcohols in the pharmaceutical field (e.g., anti-HIV, antimalarial, and antitumor drugs), materials industry (e.g., polymer modification and metal corrosion protection), and organic synthesis (e.g., chiral ligands and catalysts). Particular emphasis is placed on the biosynthetic strategies and pathways of representative amino alcohols, including ethanolamine, (2S,3R)-2-amino-1,3,4-butanetriol, (R)-3-amino-1-butanol, sphingosine, and metaraminol, as well as the metabolic engineering design principles and downstream processing technologies for amino alcohol biosynthesis. Although current biosynthetic approaches still face bottlenecks in enzyme catalytic efficiency, substrate tolerance, cofactor regeneration, product toxicity, and thermodynamic equilibrium, substantial improvements in synthetic efficiency and stereoselectivity have been achieved through protein engineering, metabolic engineering, in situ product removal, and multi-enzyme cascade optimization. This review aims to provide systematic theoretical references and technical insights for the green and efficient biomanufacturing of amino alcohols. Full article

Nanostructured Co₃O₄ was synthesized via a sol–gel approach employing the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate ([EMIm]TfO) and subsequently evaluated as a high-performance anode material for lithium-ion batteries. Ionic liquids, distinguished by their low volatility, high thermal stability, and tunable chemical properties, represent a greener alternative to conventional organic solvents for the synthesis of functional nanomaterials. The electrochemical performance of the as-prepared material was systematically assessed through galvanostatic charge–discharge cycling, cyclic voltammetry, and rate capability tests. The Co₃O₄ electrode exhibited a high reversible capacity of approximately 1100 mAh g⁻¹ after 50 cycles at a current density of 200 mA g⁻¹, along with excellent coulombic efficiency approaching ~100% after the initial cycles. Furthermore, the material demonstrated strong rate capability, delivering about 600 mAh g⁻¹ at 1 C, and recovering its capacity upon returning to lower current densities. The improved electrochemical performance is primarily attributed to the nanoscale architecture induced by the ionic liquid-assisted synthesis, which facilitates rapid lithium-ion transport and effectively buffers volume variations during repeated cycling. Notably, the ionic liquid serves a dual function as both a green reaction medium and a structure-directing agent, enabling precise control over the material’s morphology and properties. This study demonstrates a versatile strategy for the rational design of potential transition-metal oxide anodes, paving the way for high-performance electrode materials. The findings contribute to the development of next-generation lithium-ion batteries tailored for clean and sustainable energy storage applications. Full article

Antibiotic resistance has emerged as a major global health challenge, underscoring the urgent need for alternative therapeutic strategies capable of enhancing the efficacy of existing antibiotics. In this context, saponin-based nanomaterials have attracted considerable attention due to their potential as antibiotic-modulating systems. This study investigated a saponin-enriched fraction obtained from the bark of Sarcomphalus joazeiro Mart. (SEF-4), its application in the green synthesis of silver nanoparticles, and the antibiotic-modulating potential of the resulting nanoformulation. SEF-4 was obtained from the ethanolic bark extract through liquid–liquid partitioning (52% yield), followed by column chromatographic purification and chemical characterization using LC-ESI-QTOF-MS. The purified fraction was subsequently employed as both a reducing and stabilizing agent for the synthesis of silver nanoparticles (putative AgNP-SEF-4), which were physicochemically characterized. Antibacterial activity and antibiotic-modulating effects were evaluated using the broth microdilution method against standard and multidrug-resistant bacterial strains. LC-ESI-QTOF-MS analysis enabled the putative identification of five jujubogenin-type triterpenoid saponins bearing tetra-, penta-, and hexasaccharide moieties with distinct glycosylation profiles; however, the precise sugar sequence, monosaccharide composition, and glycosidic linkage positions remain to be confirmed through complementary NMR and hydrolysis studies. Although neither SEF-4 nor putative AgNP-SEF-4 displayed clinically relevant intrinsic antibacterial activity, the nanoformulation significantly enhanced the activity of aminoglycoside antibiotics. The most pronounced modulatory effects were observed against Klebsiella pneumoniae ATCC 1705 in combination with amikacin and against both standard and multidrug-resistant Escherichia coli strains when combined with gentamicin or amikacin. These findings highlight the potential of putative AgNP-SEF-4 as an antibiotic adjuvant capable of potentiating aminoglycoside efficacy and increasing bacterial susceptibility, including in multidrug-resistant strains. Full article

The overreliance on chemical pesticides has caused severe environmental contamination, health risks, and increasing pest and pathogen resistance, creating an urgent need for greener and more efficient alternatives in sustainable agriculture. Microalgae-mediated green nano-synthesis has emerged as a promising strategy because of its environmental compatibility, cost-effectiveness, and multifunctional potential. This review critically summarizes recent advances in microalgae-derived nanomaterials for agricultural applications. First, we discuss the biochemical basis of nanoparticle biosynthesis, highlighting the roles of microalgal polysaccharides, proteins, photosynthetic pigments, extracellular polymeric substances, and secondary metabolites as reducing, capping, and stabilizing agents. We then summarize intracellular and extracellular synthesis pathways, advanced synthesis strategies, and key reaction parameters, including temperature, pH, and metal precursor concentration, which regulate nanoparticle size, morphology, stability, and yield. Subsequently, major microalgae-derived nanomaterials, including gold, silver, selenium, zinc oxide, bimetallic, and other functional nanoparticles, are discussed in relation to their agricultural applications. These nanomaterials show potential in bacterial, fungal, and viral disease control, biofilm disruption, plant growth promotion, yield enhancement, and abiotic stress mitigation. Their agronomic effects are associated with multiple mechanisms, including reactive oxygen species generation, pathogen membrane disruption, inhibition of biofilm formation, enhanced nutrient bioavailability, antioxidant regulation, and activation of plant systemic resistance. In addition, this review evaluates the phytotoxicity, biocompatibility, soil microbial impacts, and environmental safety of microalgae-derived nanomaterials, emphasizing that green synthesis does not automatically guarantee biosafety. Finally, we discuss their integration into circular agriculture through CO₂ capture and wastewater-derived metal recovery, while highlighting remaining challenges in scale-up, quality control, economic feasibility, regulatory classification, and public acceptance. Overall, microalgae-mediated nanotechnology offers a promising platform for developing safer, more efficient, and circular agricultural inputs. Full article

Metal oxide nanoparticles serve as crucial drivers in modern biomedical, catalytic, environmental, and energy technologies due to their high surface-to-volume ratios and quantum confinement properties. Traditional chemical and physical synthesis methods remain limited by significant energy footprints, high costs, and the use of hazardous reagents. To address these challenges, bioinspired (“green”) synthesis has emerged as a sustainable paradigm that employs biological systems as nature nanofactories. This critical review provides a provides a comprehensive and systematic analysis of the green synthesis of major metal oxide systems (ZnO, TiO₂, Fe₃O₄/Fe₂O₃, CuO, Co₃O₄, CeO_2, and MnO₂) using diverse biological templates, including plant extracts, bacteria, fungi, algae, and biopolymers. Moving beyond simple descriptive summaries, we critically evaluate the foundational electron-transfer and nucleation mechanism, systematically correlate processing parameters with physical outcomes, and offer a rigorous comparative analysis across different biological kingdoms. Finally, we directly address the underlying challenges facing the field: reproducibility bottlenecks, scalability limits, environmental safety variations, and regulatory hurdles necessary for industrial translation. Full article

Turning waste materials into renewed value is a central aspect of any future circular (bio)economy. Urine and ash are two prominent waste materials produced globally and in considerable amounts each year. Both contain several interesting substances that are so far de facto lost or may even pose a threat to the environment. Urine from industrial-scale farming, for instance, is responsible for significant pollution of soil and groundwater with nitrogen and phosphorous, yet N and P are also high-demand substances in agriculture and industry. Similarly, ash is rich in several interesting metal ions, but is still usually disposed of in a landfill. Using a sequence of simple yet effective biological and chemical processes, it may be possible to convert these two unwanted materials into “green” ammonia and calcium phosphate, both valuable high-demand substances with numerous applications, and with few potentially valuable leftovers still to be dealt with. Eventually, and after considering some of the logistics of the process, such as the collection of materials, this “urinash process” may be upscaled to effectively reduce waste by turning it into renewed value, thus also substituting for—some of—both the energy-intensive synthesis of grey ammonia and the destructive mining for phosphate salts. Full article

Perillyl alcohol, a rare monoterpenoid, can be widely used in chemical, agriculture, and food industries and shows promise in medicine as an anticancer agent. The artificial synthesis of perillyl alcohol from β-pinene epoxide using inexpensive and abundant turpentine is chosen for improving its pharmaceutical and industrial applications. This work presents a green and sustainable catalytic process for the rearrangement of β-pinene epoxide to perillyl alcohol. A novel ammonium phosphomolybdate solid acid (AC-COIMI-NH₄PMo) was built via phosphomolybdic acid chemisorption onto an N-basylous site of imidazolized activated carbon followed by ammonia fumigation, which exhibits outstanding catalytic performance in the rearrangement of β-pinene epoxide to perillyl alcohol in nitromethane under mild conditions. At 80 °C over 80 min, nearly complete conversion of the epoxide is achieved with a perillyl alcohol selectivity of 77.3%. Moreover, the used catalyst can be readily recycled after washing with hot nitromethane. The favorable proton-donating capacity of nitromethane for the rearrangement and the comparison of adsorption energies between substrates and main products on ammonium phosphomolybdate are revealed through DFT calculation. Kinetic analysis based on the Langmuir adsorption model indicates that the surface reaction of strongly adsorbed β-pinene epoxide is a rate-determining step and follows a zero-order reaction process; the activation energy is 29.64 kJ/mol within the temperature range of 50–80 °C. Finally, a parallel catalytic rearrangement mechanism is proposed, and an eight-step reaction pathway toward perillyl alcohol is elaborated for β-pinene epoxide conversion on AC-COIMI-NH₄PMo. Full article

Selenium (Se) is a beneficial element involved in plant growth, metabolism, stress adaptation, and crop quality improvement, but its effects are strongly influenced by chemical form, application dose, plant species, growth stage, and environmental conditions. To integrate mechanistic understanding with global research trends, this study combines a concise mini-review with a bibliometric analysis of Se research in plants from 2000 to 2025. The mini-review summarizes Se speciation and bioavailability in the soil–plant–microbe system, root uptake and long-distance transport, metabolic assimilation and detoxification, physiological regulation, stress tolerance, biofortification, and nano-Se applications. Bibliographic data were retrieved from the Web of Science Core Collection and analyzed using CiteSpace, VOSviewer, and Scimago Graphica. A total of 3451 valid publications were identified, showing a sustained increase in annual output, especially after 2018. The field has expanded from early studies on Se speciation, uptake, assimilation, and antioxidant responses toward broader themes involving crop biofortification, molecular regulation, stress physiology, foliar application, nano-Se applications, green synthesis, and phytoremediation. Overall, plant Se research has evolved into an interdisciplinary field linking mechanistic studies with safe agricultural application. Future work should emphasize standardized experimental frameworks, causal mechanism validation, precise biofortification, field-based evaluation, and safety assessment of emerging Se-based technologies. Full article

Flavor esters are valuable compounds widely used in the food, beverage, and cosmetics industries for their aroma and flavor-enhancing properties. Traditional methods of obtaining these compounds, such as extraction from natural sources or chemical synthesis, present challenges related to cost and toxicity, respectively. Enzymatic synthesis, particularly using immobilized lipases, offers a sustainable and efficient alternative. This study investigates the application of CRL immobilized on Diaion HP-20 for geranyl butyrate synthesis via esterification of geraniol and butanoic acid using Candida rugosa lipase (CRL) immobilized on Diaion HP-20 (CRL-DHP-20). The immobilization process resulted in a protein loading of 29.6 ± 2.2 mg/g support from an initial 40 mg/g, and the immobilized biocatalyst exhibited a hydrolytic activity of 124.0 ± 2.5 U/g using olive oil emulsion. Reaction conditions were optimized through a central composite design, evaluating the influence of biocatalyst concentration, temperature, and agitation on ester conversion. The optimal conditions (13.4% CRL-DHP-20, 48.2 °C, and 220.1 rpm) led to 85.4% conversion in 360 min. Additionally, CRL-DHP-20 retained 84% of its initial activity after six reaction cycles, indicating good operational stability. These findings highlight the potential of CRL-DHP-20 as an effective and reusable biocatalyst for green synthesis of flavor esters. Full article

Volatile fatty acids (VFAs) are essential precursors in chemical synthesis for various chemicals, polymers, pharmaceuticals, and fragrance compounds. Acidogenic anaerobic digestion (or arrested methanogenesis) is a promising method to stabilize organic wastes and convert them to value-added products such as VFAs. However, the VFAs’ accumulation could in turn suppress the fermentation process through product inhibition and limit the titer of VFA in the digestate. Therefore, in situ separation and recovery of VFAs from the fermentate is crucial to constructing an effective continuous VFA-producing system. Recent research has been dedicated to addressing these issues and advancing the utilization of biobased VFAs, particularly through process-intensified strategies employing novel green solvents such as natural deep eutectic solvents. Furthermore, in situ conversion of VFAs into esters is another potential strategy for VFA removal. However, VFA esterification in an aqueous medium is challenging due to the abundant water driving the reaction toward hydrolysis. Recent advances in free or immobilized enzyme catalysis in solvents have demonstrated improved ester yield by providing a hydrophobic space for the esterification reaction in aqueous solution. In this review, we present an overview of critical aspects on the state-of-the-art of green solvent-based process intensification strategies, including feedstock selection and pretreatment, operating condition optimization, advances in membrane- and solvent-based recovery methods, and biocatalytic in situ esterification. Lastly, we provide perspectives toward cost-effective, continuous, high-solid, environmental-benign, and industrial-relevant VFA production applications. Full article

The misuse of antibiotics is causing widespread antibiotic resistance, creating an urgent need for new treatment options such as nanoparticle-based therapies. This study aimed to compare silver nanoparticles (AgNPs) produced via green synthesis methods with those made through traditional chemical processes. Furthermore, the study investigated and contrasted the bacterial responses to these two types of AgNPs over a 21-day period of selection pressure using experimental evolution techniques. Analysis using scanning electron microscopy and transmission electron microscopy revealed a consistent, uniform morphology among the AgNPs produced via chemical methods. In contrast, AgNPs synthesized through green methods displayed an irregular morphology. Despite these morphological differences, all nanoparticles from both synthesis approaches were under 100 nm in diameter. These findings were further supported by the absorption spectrum data, which showed a maximum absorption peak between the 400 and 500 nm wavelength range. E. coli exposed to green synthesized AgNPs for 21 days adapted to their presence, exhibiting both enhanced resistance to the green synthesized AgNPs themselves and the development of cross-resistance to ionic silver, a pattern not observed in chemically synthesized AgNP-selected populations. Populations selected using chemical synthesized AgNPs did not develop increased resistance to either chemically or green synthesized AgNPs; however, they showed a slight increase in resistance to ionic silver. Genomics analysis identified polymorphism in genes in a green synthesized AgNP-resistant line including but not limited to the multidrug efflux transporter system (EmrAB), DUF4756 family protein (D1792_RS05680), putative zinc-binding protein YnfU/cold shock-like protein (ynfU/cspB) and imcF-related family protein (D1792_RS10035). Bacterial resistance to chemical AgNPs involves specific polymorphisms in key bacterial components like the RNA polymerase sigma factor (RpoE) and the EmrAB efflux pump. Collectively, the method used to synthesize the AgNPs influences their antibacterial efficacy and the likelihood of bacteria developing resistance. Understanding this interaction is vital for developing effective and resistance-controlled applications of AgNPs across medicine, environmental science, and industry. Full article

Deep eutectic solvent (DES) extraction is a green and efficient technology. As a substitute for organic reagents, DESs are widely used to extract active ingredients from traditional Chinese medicine. This study established an environmentally friendly and efficient method for extracting astaxanthin (AST) from Phaffia rhodozyma (PR) using ultrasound-assisted deep eutectic solvents (DESs-UAE). The astaxanthin content was determined by high-performance liquid chromatography (HPLC). Six types of deep eutectic solvents composed of DL-menthol and selected hydrogen bond donors were prepared and evaluated, among which the DL-menthol–acetic acid system showed superior extraction performance. Response surface methodology (RSM) was employed to optimize extraction parameters (ultrasonic power, time, and temperature), and the optimal conditions were determined as follows: ultrasonic power 420 W, ultrasonic time 20 min, and ultrasonic temperature 60 °C, achieving an AST extraction rate of 62% (2.49 mg/g). Compared with conventional organic solvent extraction, DESs exhibited a significantly higher AST extraction rate from PR, except for dimethyl sulfoxide (DMSO). Scanning electron microscopy (SEM) analysis demonstrated that DES-UAE treatment disrupted the cellular structure of PR, resulting in numerous surface pores; this facilitated the release of intracellular bioactive components and significantly improved AST extraction efficiency. The PR extract showed no significant cytotoxicity and could effectively promote L929 cell proliferation. It concentration-dependently increased superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) content in H₂O₂-induced oxidative stress L929 cells, thereby alleviating oxidative damage. Additionally, it concentration-dependently upregulated type I collagen expression in these cells, ameliorated the decline in collagen synthesis function, and exerted a protective effect against cellular oxidative damage. This study provides a green alternative to toxic solvents and offers important theoretical and chemical support for the extraction of natural products and the high-value utilization of Phaffia rhodozyma (PR). Deep eutectic solvents have emerged as promising green alternatives to hazardous organic solvents, yet hydrophobic DESs tailored for lipophilic astaxanthin extraction from Phaffia rhodozyma and the linkage between extraction performance and anti-aging bioactivity remain insufficiently explored. Here, an ultrasound-assisted hydrophobic deep eutectic solvent extraction strategy was constructed to acquire astaxanthin, aiming to overcome low efficiency and environmental risks of conventional organic extraction techniques. Six DL-menthol-based DESs were prepared and screened, and DL-menthol–acetic acid possessed the optimal extraction capacity. Key extraction parameters were optimized via response surface methodology, and the maximum astaxanthin extraction recovery reached 62% (2.49 mg/g) under 420 W ultrasonic power, 20 min treatment and 60 °C. This yield was markedly higher than that of most common organic solvents; though comparable extraction effect was obtained with DMSO, the adopted DES possessed outstanding low-toxic and biodegradable superiorities that DMSO cannot match. SEM characterization verified that the combined treatment destroyed yeast cell structure and formed porous morphology, which accelerated intracellular astaxanthin release and accounted for improved extraction efficiency. Biological assays proved the extract possessed good biosafety and proliferation-promoting effect on L929 cells. It effectively relieved cellular oxidative injury by elevating the SOD level and reducing MDA accumulation in oxidative damaged cells, and upregulated type I collagen expression to mitigate aging-related collagen loss. This work develops an eco-friendly and high-efficiency extraction route for lipophilic active substance, confirms the practical value of hydrophobic DES, and provides experimental basis for high-value utilization of Phaffia rhodozyma resources. Full article

Green ammonia systems provide an important pathway for converting fluctuating renewable electricity into transportable chemical products. To address the coupled challenges of renewable power variability, heterogeneous electrolyzer dynamics, hydrogen storage constraints, and continuous ammonia synthesis under weak-grid conditions, this paper develops a mixed-integer linear programming scheduling model considering the coordination and start–stop characteristics of ALK–PEM hybrid electrolyzers. The model uses a 15 min resolution over a two-day horizon and integrates renewable power supply, grid electricity purchase, electrolysis, hydrogen storage, and flexible ammonia synthesis in a unified framework. The off, hot-standby, and running states of ALK and PEM electrolyzers are explicitly represented. The case results show that, under the high-renewable-resource scenario, ammonia production reaches 494.93 t, with a curtailment ratio of 3.23% and a grid electricity share of 0.68%, indicating strong renewable-energy conversion capability. Under the low-renewable-resource scenario, ammonia production decreases to 180.09 t and the grid electricity share increases to 40%, showing that the operating priority shifts to maintaining continuous production and safe hydrogen inventory. The ALK hydrogen production share decreases from 93.96% in the high-resource scenario to 75.66% in the low-resource scenario, while the PEM share increases from 6.04% to 24.34%. This indicates that ALK mainly supports large-scale base-load hydrogen production under abundant renewable resources, whereas PEM provides fast compensation and marginal regulation when renewable resources are limited and more volatile. The results demonstrate that ALK base-load production, PEM fast regulation, hydrogen storage buffering, and platform-like flexible ammonia operation jointly provide the main flexibility sources in the studied weak-grid green ammonia system. Full article

Waste cooking oils (WCO) are large-scale residual streams from domestic and industrial food processing. Their improper disposal poses severe environmental risks, yet their integration into the oleochemical sector offers a strategic opportunity for the green transition by substituting fossil-based feedstocks. This systematic review provides a comprehensive assessment of WCO valorization as a sustainable precursor for high-value products, specifically biopolymers, bioplasticizers, and biolubricants. The study followed the PRISMA 2020 guidelines, searching PubMed, Scopus, and MDPI databases (up to September 2025). The search strategy utilized combinations of keywords present in the title. Inclusion criteria focused on peer-reviewed chemical and biotechnological conversion pathways published in English within the last decade. Studies addressing biofuel production, patents, and review were excluded. Screening, data extraction, and qualitative risk of bias assessment, centered on experimental reproducibility and reporting transparency, were performed independently by multiple reviewers. From an initial pool of 2637 records, 87 studies met the eligibility criteria. The analysis reveals that polyhydroxyalkanoates (PHAs) represent the most extensively researched pathway, followed by WCO-derived epoxides and innovative biolubricant formulations. While several studies report high conversion yields under optimized conditions, the transition from bench-scale to industrial implementation remains hindered by the heterogeneous composition of WCO and a lack of standardized pre-treatment protocols. WCO valorization shows transformative potential for the circular economy, offering a dual benefit of waste mitigation and sustainable material synthesis. However, future research must address scalability challenges and feedstock variability. This review identifies emerging trends and provides a roadmap for the industrial adoption of WCO-based processes in the framework of clean technologies. Full article

Green synthesis of metal oxide nanoparticles (NPs) offers an eco-friendly, cost-effective alternative to conventional chemical and physical methods, minimizing energy use and hazardous reagents. This study demonstrates the biogenic production of manganese oxide (MnO) NPs using Catharanthus roseus flower extract as a reducing and capping agent, Comprehensive characterization via FTIR (Mn–O vibrations at 591–405 cm⁻¹ along the capping groups), XRD (confirms the cubic crystalline phase), FESEM (flaky, agglomerated sheets), EDX (Mn 62.37%, O 28.40% and C 9.23%), zeta potential (−0.3 mV), and TGA (33.7% phased mass loss to 985 °C) verified pure and stable MnO NPs. In vitro assays on L929 fibroblasts revealed dose-dependent MTT cytotoxicity (78.77% viability at 20 µg/mL to 39.97% at 100 µg/mL) yet enhanced scratch wound closure (−16.31% area reduction vs. −17.41% control), alongside potent antibacterial activity with highest inhibition zones of 15 mm against Klebsiella pneumoniae and Escherichia coli, and lowest of 4 mm against Pseudomonas aeruginosa at 40–100 µg/mL. These multifaceted properties highlight C. roseus-assisted MnO NPs’ promise for wound healing and antimicrobial applications, warranting dosage optimization and in vivo studies. Full article