Green Synthesis Research Articles

Acetal-thiol Click-like Reaction: Facile and Efficient Synthesis of Dynamic Dithioacetals and Recyclable Polydithioacetals.

Dithioacetals are heavily used in organic, material and medical chemistries, and exhibit huge potential to synthesize degradable or recyclable polymers. However, the current synthetic approaches of dithioacetals and polydithioacetals are overwhelmingly dependent on external catalysts and organic solvents. Herein, we disclose a catalyst- and solvent-free acetal-thiol click-like reaction for synthesizing dithioacetals and polydithioacetals. High conversion, higher than acid catalytic acetal-thiol reaction, can be achieved. High universality was confirmed by monitoring the reactions of linear and cyclic acetals (including renewable bio-sourced furan-acetal) with aliphatic and aromatic thiols, and the reaction mechanism of monomolecular nucleophilic substitution (SN1) and auto-protonation (activation) by thiol was clarified by combining experiments and density functional theory computation. Subsequently, we utilize this reaction to synthesize readily recyclable polydithioacetals. By simple heating and stirring, linear polydithioacetals with w of ~110 kDa were synthesized from acetal and dithiol, and depolymerization into macrocyclic dithioacetal and repolymerization into polydithioacetal can be achieved; through reactive extrusion, a semi-interpenetrating polymer dynamic network with excellent mechanical properties and continuous reprocessability was prepared from poly(vinyl butyral) and pentaerythritol tetrakis(3-mercaptopropionate). This green and high-efficient synthesis method for dithioacetals and polydithioacetals is beneficial to the sustainable development of chemistry.

A sustainable green-approach for biofabrication of chitosan nanoparticles, optimization, characterization, its antifungal activity against phytopathogenic Fusarium culmorum and antitumor activity.

Chitosan is a natural non-toxic, biocompatible, biodegradable, and mucoadhesive polymer. It also has a broad spectrum of applications such as agriculture, medical fields, cosmetics and food industries. In this investigation, chitosan nanoparticles were produced by an aqueous extract of Cympopogon citratus leaves as a reducing agent. According to the SEM and TEM micrographs, CNPs had a spherical shape, and size ranging from 8.08 to 12.01 nm. CNPs have a positively charged surface with a Zeta potential of + 26mV. The crystalline feature of CNPs is determined by X-ray diffraction. There are many functional groups, including C꞊C, CH2-OH, C-O, C-S, N-H, CN, CH and OH were detected by FTIR analysis. As shown by the thermogravimetric study, CNPs have a high thermal stability. For the optimization of the green synthesis of CNPs, a Face centered central composite design (FCCCD) with 30 trials was used. The maximum yield of CNPs (13.99 mg CNPs/mL) was produced with chitosan concentration 1.5%, pH 4.5 at 40°C, and incubation period of 30 min. The antifungal activity of CNPs was evaluated against phytopathogenic fungus; Fusarium culmorum. A 100% rate of mycelial growth inhibition was gained by the application of 20mg CNPs/mL. The antitumor activity of the green synthesized CNPs was examined using 6 different cell lines, the viability of the cells reduced when the concentration of green synthesized CNPs increased, the IC50 dose of the green synthesized CNPs on the examined cell lines HePG-2, MCF-7, HCT-116, PC-3, Hela and WI-38 was 36.25 ± 2.3, 31.21 ± 2.2, 67.45 ± 3.5, 56.30 ± 3.3, 44.62 ± 2.6 and 74.90 ± 3.8; respectively.

Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Catharanthus roseus Extract: A Novel Approach

Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Catharanthus roseus Extract: A Novel Approach

Green and sustainable synthesis of the ZnONPs using leaf extract of Guazuma ulmifolia for antioxidant and antimicrobial activities

Green and sustainable synthesis of the ZnONPs using leaf extract of Guazuma ulmifolia for antioxidant and antimicrobial activities

Aqueous AlCl3/ZnCl2 solution room-induced the self-growing strategy of expanded topological network for cellulose/polyacrylamide-based solid-state electrolytes.

The green synthesis strategy for cellulose-containing hydrogel electrolytes is significant for effectively managing resources, energy, and environmental concerns in the contemporary world. Herein, we propose an all-green strategy using AlCl3/ZnCl2/H2O solvent to create cellulose/polyacrylamide-based hydrogel (AZ-Cel/PAM) with expanded hierarchical topologies. The aqueous AlCl3/ZnCl2 facilitates the efficient dissolution of cellulose at room temperature, and the dispersed Al3+-Zn2+ ions autocatalytic system catalyzes in-situ polymerization of acrylamide (AM) monomer. This expands the AM network within the cellulose framework, forming multiple bonding interactions and stable ion channels. The resulting hybrid hydrogel exhibits improved mechanical properties (tensile strength of 56.54kPa and compressive strength of 359.43kPa) and enhanced ionic conductivity (1.99 S/m). Furthermore, it also demonstrates excellent adhesion, freeze resistance (-45°C), and water retention capabilities. Quantum simulations further clarify the mechanical composition and ion transport mechanism of AZ-Cel/PAM hydrogels. The assembled supercapacitor with the hydrogel electrolyte, demonstrates an ideal area-specific capacitance of 203.80 mF/cm2. This all-green strategy presents a novel approach to developing sustainable energy storage devices.

Green Synthesis, Characterization and Application of Silver Nanoparticles Using Bioflocculant: A Review

Nanotechnology has emerged as an effective means of removing contaminants from water. Traditional techniques for producing nanoparticles, such as physical methods (condensation and evaporation) and chemical methods (oxidation and reduction), have demonstrated high efficiency. However, these methods come with certain drawbacks, including the significant energy requirement and the use of costly and hazardous chemicals that may cause nanoparticles to adhere to surfaces. To address these limitations, researchers are actively developing alternative procedures that are cost-effective, environmentally safe, and user-friendly. One promising approach involves biological synthesis, which utilizes plants or microorganisms as reducing and capping agents. This review discusses various methods of nanoparticle synthesis, with a focus on biological synthesis using naturally occurring bioflocculants from microorganisms. Bioflocculants offer several advantages, including harmlessness, biodegradability, and minimal secondary pollution. Furthermore, the review covers the characterization of synthesized nanoparticles, their antimicrobial activity, and cytotoxicity. Additionally, it explores the utilization of these NPs in water purification and dye removal processes.

Bioprospecting of Aspergillus sp. as a promising repository for anti-cancer agents: a comprehensive bibliometric investigation

Cancer remains a significant global health challenge, claiming nearly 10 million lives in 2020 according to the World Health Organization. In the quest for novel treatments, fungi, especially Aspergillus species, have emerged as a valuable source of bioactive compounds with promising anticancer properties. This study conducts a comprehensive bibliometric analysis to map the research landscape of Aspergillus in oncology, examining publications from 1982 to the present. We observed a marked increase in research activity starting in 2000, with a notable peak from 2005 onwards. The analysis identifies key contributors, including Mohamed GG, who has authored 15 papers with 322 citations, and El-Sayed Asa, with 14 papers and 264 citations. Leading countries in this research field include India, Egypt, and China, with King Saud University and Cairo University as the leading institutions. Prominent research themes identified are “endophyte,” “green synthesis,” “antimicrobial,” “anti-cancer,” and “biological activities,” indicating a shift towards environmentally sustainable drug development. Our findings highlight the considerable potential of Aspergillus for developing new anticancer therapies and underscore the necessity for further research to harness these natural compounds for clinical use.

Chemoenzymatic Synthesis of 2-Aryl Thiazolines from 4-Hydroxybenzaldehydes Using Vanillyl Alcohol Oxidases.

Nitrogen heterocycles are commonly found in bioactive natural products and drugs. However, the biocatalytic tools for nitrogen heterocycle synthesis are limited. Herein, we report the discovery of vanillyl alcohol oxidases (VAOs) as efficient biocatalysts for the one-pot synthesis of 2-aryl thiazolines from various 4-hydroxybenzaldehydes and aminothiols. The wild-type biocatalyst features a broad scope of 4-hydroxybenzaldehydes. Though the scope of aminothiols is limited, it could be improved via semi-rational protein engineering, generating a variant to produce previously inaccessible cysteine-derived bioactive 2-aryl thiazolines using the wild-type VAO. Benefiting from the derivatizable functional groups in the enzymatic products, we further chemically modified these products to expand the chemical space, offering a new chemoenzymatic strategy for the green and efficient synthesis of structurally diverse 2-aryl-thiazoline derivatives to prompt their use in drug discovery and catalysis.

Metal-Organic Framework Templated Z-Scheme ZnIn2S4/Bi2S3 Hierarchical Heterojunction for Photocatalytic H2O2 Production from Wastewater.

Metal-organic framework derived materials received a lot of attention due to their significant benefits in photocatalytic reactions. In this work, a Z-scheme ZnIn2S4/Bi2S3 hierarchical heterojunction is first developed by a one-pot method using CAU-17 as a template. The specific preparation method endows an intimate interface contact between these two monomers, and CAU-17-derived Bi2S3 possesses a high surface area and porosity, resulting in an efficient charge separation and O2 capture. Thus, for photocatalytic H2O2 production from the O2 reduction reaction, the ZnIn2S4/Bi2S3 heterojunction can achieve an H2O2 yield of 995µmolL-1 in pure water and ambient air under visible light, 4.5 and 4 times that of ZnIn2S4 and Bi2S3, respectively. In addition, in tetracycline solution, ZnIn2S4/Bi2S3 can degrade tetracycline with a degradation rate of 95% by photocatalysis, and at the same time, a final H2O2 production yield of 1223µmolL-1 is reached. Similarly, high yields of H2O2 are also obtained from wastewater containing o-nitrophenol, acid golden yellow, or acid red, and these pollutants are effectively degraded. This work reveals the potential of metal-organic framework-derived materials in photocatalysis, as well as provides insights into H2O2 green synthesis and wastewater treatment.

Ceria nanoparticles: biomedical applications and toxicity.

Ceria nanoparticles (CeO2 NPs) have become popular materials in biomedical and industrial fields due to their potential applications in anti-oxidation, cancer therapy, photocatalytic degradation of pollutants, sensors, etc. Many methods, including gas phase, solid phase, liquid phase, and the newly proposed green synthesis method, have been reported for the synthesis of CeO2 NPs. Due to the wide application of CeO2 NPs, concerns about their adverse impacts on human health have been raised. This review covers recent studies on the biomedical applications of CeO2 NPs, including their use in the treatment of various diseases (e.‍g., Alzheimer's disease, ischemic stroke, retinal damage, chronic inflammation, and cancer). CeO2 NP toxicity is discussed in terms of the different systems of the human body (e.‍g., cytotoxicity, genotoxicity, respiratory toxicity, neurotoxicity, and hepatotoxicity). This comprehensive review covers both fundamental discoveries and exploratory progress in CeO2 NP research that may lead to practical developments in the future.

Instant green synthesis: obtaining stable nanoparticles and understanding the extract's behavior in the particle formation mechanism

Numerous plant extracts are abundant in biomolecules that can be employed in the biogenic synthesis of metallic nanoparticles owing to their potent reducing capabilities. The mechanism by which biomolecules act as reducers and expedite the reduction of silver ions remains poorly understood. This study presents an instantaneous and environmentally friendly synthesis of silver nanoparticles (AgNPs) using varying concentrations of commercially available green tea and concentrations of a dextrose-reducing solution. The AgNPs formed instantaneously, likely due to the competitive reaction between the polyphenols present in green tea and the dextrose. The best AgNPs produced using a diluted green tea solution at a concentration of 0.05 g of tea/ml and 100 μl of dextrose solution exhibited high stability over a period of 90 days, as confirmed by UV–vis spectroscopy and dynamic light scattering. The results of antioxidant properties from diluited tea showed 2,2-diphenyl-1-picrylhydrazyl (DPPH) 0.013 ± (0.1) μmol Trolox Equivalent Anyioxidant Capacity (TEAC) TEAC/g, Ferric Reducing Antioxidant Power (FRAP) 10.3 ± (0.1) μmol TEAC/g and Total Polyphenol Content (TPC) 0.12 ± (.001) μgGAE(Galic Acid Equivalent)/g). The resulting nanoparticles are extremely small, measuring approximately 30 to 50 nm in size, and exhibit a spherical morphology as evidenced by SEM imaging. The plasmon bandwidth is better in more diluted tea and higher proportions of dextrose added than the others condition of synthesis. Probably, the results of 2nd extraction of green tea diluted can be evidence that phenolic compounds, mainly, caffeine and gallic acid, are contributing to forming and stabilizing the silver nanoparticles. This fundamental knowledge showed the method employed is ecologically sound and adheres to green principles.

Assessment of the Effect of Surface Modification of Metal Oxides on Silver Nanoparticles: Optical Properties and Potential Toxicity.

Silver nanoparticles (AgNPs) have garnered significant interest due to their distinctive properties and potential applications. Traditional fabrication methods for nanoparticles often involve high-energy physical conditions and the use of toxic solvents. Various green synthesis approaches have been developed to circumvent these issues and produce environmentally benign nanoparticles. Our study focuses on the green synthesis of AgNPs using L-ascorbic acid and explores the modification of their properties to enhance antibacterial and anticancer effects. This is achieved by coating the nanoparticles with Zinc oxide (ZnO) and Silica oxide (SiO2), which alters their optical properties in the visible spectrum. The synthesized formulations-AgNPs, zinc oxide-silver nanoparticles (Ag@ZnO), and silica oxide-silver nanoparticles (Ag@SiO2) core/shell nanoparticles-were characterized using a suite of physicochemical techniques, including Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), Zeta potential measurement, UV-Vis spectroscopy, Refractive Index Measurements, and Optical Anisotropy Assessment. TEM imaging revealed particle sizes of 11 nm for AgNPs, 8 nm for Ag@ZnO, and 400 nm for Ag@SiO2. The Zeta potential values for Ag@ZnO and Ag@SiO2 were measured at -17.0 ± 5 mV and -65.0 ± 8 mV, respectively. UV-Vis absorption spectra were recorded for all formulations in the 320 nm to 600 nm wavelength range. The refractive index of AgNPs at 404.7 nm was 1.34572, with slight shifts observed for Ag@ZnO and Ag@SiO2 to 1.34326 and 1.37378, respectively. The cytotoxicity of the nanocomposites against breast cancer cell lines (MCF-7) was assessed using the MTT assay. The results indicated that AgNPs and Ag@ZnO exhibited potent therapeutic effects, with IC50 values of 494.00 µg/mL and 430.00 µg/mL, respectively, compared to 4247.20 µg/mL for Ag@SiO2. Additionally, the antibacterial efficacy of AgNPs was significantly enhanced under visible light irradiation. Ag@ZnO demonstrated substantial antibacterial activity both with and without light exposure, while the Ag@SiO2 nanocomposites significantly reduced the inherent antibacterial activity of silver. Conversely, the Ag@ZnO nanocomposites displayed pronounced antibacterial and anticancer activities. The findings suggest that silver-based nanocomposites, particularly Ag@ZnO, could be practical tools in water treatment and the pharmaceutical industry due to their enhanced therapeutic properties.

Green synthesis, characterisation, and antibacterial activity of silver nanoparticles obtained from Salvia officinalis extract

Green synthesis, characterisation, and antibacterial activity of silver nanoparticles obtained from Salvia officinalis extract

Synthesis and characterization of Cu-modified ox-g-C3N4 nanosheets as an electrode for green synthesis of phenyl Benzofuran derivatives via C–H functionalization to C–O and C–C bond formation with an electrochemical oxidation system

Synthesis and characterization of Cu-modified ox-g-C3N4 nanosheets as an electrode for green synthesis of phenyl Benzofuran derivatives via C–H functionalization to C–O and C–C bond formation with an electrochemical oxidation system

Progress in Electrochemically Empowered C-O Bond Formation: Unveiling the Pathway of Efficient Green Synthesis.

(C-X) bonds (X=C, N, O) are the main backbone for making different skeleton in the organic synthetic transformations. Among all the sustainable techniques, electro-organic synthesis for C-X bond formation is the advanced tool as it offers a greener and more cost-effective approach to chemical reactions by utilizing electrons as reagents. In this review, we want to explore the recent advancements in electrochemical C-O bond formation. The electrochemically driven C-O bond formation represents an emerging and exciting area of research. In this context, electrochemical techniques offers numerous advantages, including higher yields, cost-efficient production, and simplified work-up procedures. This method enables the continuous and consistent formation of C-O bonds in molecules, significantly enhancing overall reaction yields. Furthermore, both intramolecular and intermolecular C-O bond forming reaction provided valuable products of O-containing acyclic/cyclic analogue. Hence, carbonyl (C=O), ether -O-), and ester (-COOR) functionalization in both cyclic/acyclic analogues have been prepared continuously via this innovative pathway. In this context, we want to discuss one-decade electrochemical synthetic pathways of various C-O bond contains functional group in chronological manner. This review focused on all the synthetic aspects including mechanistic path and has also mentioned overall critical finding regarding the C-O bond formation via electrochemical pathways.

Study of Antioxidant, Antimicrobial and Cytotoxic Activities of Ag-Co Bimetallic Nanoparticles Biosynthesized from Red Alga (Amphiroa sp.)

Study of Antioxidant, Antimicrobial and Cytotoxic Activities of Ag-Co Bimetallic Nanoparticles Biosynthesized from Red Alga (Amphiroa sp.)

A Recent Trends on Green Synthesis and Bioactivity of Imidazole

Imidazole is a five-membered, planar heterocyclic ring made up of 3C, 2N, and N in the 1st and 3rd places. Purine, histamine, histidine, and nucleic acid are only a few significant natural compounds that contain the imidazole ring. It is utilised as a cure to optimize the solubility and bioavailability properties of proposed weakly soluble lead compounds since it is an aromatic chemical that is polar and ionizable and so improves the pharmacokinetic features of lead molecules. Derivatives of imidazole have a special place in medicinal chemistry. An essential synthesis technique in the process of discovering new drugs is the integration of the imidazole nucleus. Due to the remarkable therapeutic efficacy of medications related to imidazole, medicinal chemists have been inspired to create numerous innovative chemotherapy agents. This review summarized the work that has been done in recent years about different synthetic approaches of imidazole derivatives and their potential activity as anti-HIV, anticancer, anticovid, antifungal, antidiabetic, antidepressant, antioxidant, and antituberculosis.

Biogenic silver nanoparticle synthesis using orange peel extract and its multifaceted biomedical application.

The aim of this study was to employ an agro-industrial byproduct, specifically Citrus sinensis peels, as a reservoir of polyphenols. The natural chemicals present in C. sinensis peels serve as reducing agents in an environmentally benign method for synthesizing silver nanoparticles (AgNPs). This methodology not only provides a more environmentally friendly method for synthesizing nanoparticles but also enhances the value of agricultural waste, emphasizing the sustainable utilization of resources. In our study, AgNPs were successfully synthesized using peel aqueous exact of C. sinensis and then their various biological activity has been investigated. The synthesized AgNPs were characterized by UV-vis spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM) analysis. Furthermore, their effectiveness in inhibiting growth and biofilm formation of Escherichia coli, Staphylococcus aureus, and Candida albicans has been investigated. The minimum inhibitory concentrations (MIC) for E. coli and S. aureus were both 32μg/mL, and for C. albicans, it was 128µg/mL. At 250µg/mL of AgNPs, 94% and 92% biofilm inhibition were observed against E. coli and S. aureus, respectively. Furthermore, AgNPs demonstrated significant toxic effects against human prostate cancer cell line DU145 as investigated by anti-apoptotic, 4',6-diamidino-2-phenylindole (DAPI), reactive oxygen species (ROS), and acridine orange/ethidium bromide (AO/EtBr) assays. We also conducted uptake analysis on these pathogens and cancer cell lines to preliminarily investigate the mechanisms underlying their toxic effects. These findings confirm that AgNPs can serve as a cost-effective, non-toxic, and environmentally friendly resource for green synthesis of medicinal AgNPs. Moreover, this approach offers an alternative recycling strategy that contributes to the sustainable use of biological by-products.

Green synthesis of cellulose/ZrO2 nanocomposite: assessment of antibacterial and photocatalytic activity

Green synthesis of cellulose/ZrO2 nanocomposite: assessment of antibacterial and photocatalytic activity

Microwave-assisted green synthesis of silver nanoparticles and chitosan nanocomposites for the removal of reactive blue-19

Microwave-assisted green synthesis of silver nanoparticles and chitosan nanocomposites for the removal of reactive blue-19