Principles Of Green Chemistry Research Articles

Synthesis of Molsidomine and Mesocarb Analog via Mechanochemistry

AbstractIminosydnones (ImSyds) have renowned biological activities and attractive chemical properties for chemical biology. However, access to N6‐functionalized iminosydnones involves tricky and hazardous procedures. Thanks to an innovative mechanochemical strategy using 1,1’‐carbonyldiimidazole (CDI) as an activating agent, a straightforward synthesis of molsidomine and of a mesocarb analog, two bioactive iminosydnones, was achieved. The whole process, involving 4 linear steps, was carried out in the solid state by ball‐milling and with safe reagents, offering efficient and sustainable access to N‐carbonylated iminosydnones, in agreement with the principles of green chemistry.

Optimizing Copper Adsorption from Aqueous Solutions with Modified Rice Straw Using Response Surface Methodology

Heavy metal contamination poses an impulsive threat to human and aquatic life and ecosystem health. To ensure safe and sustainable water accessibility, biosorption with low-cost adsorbents is acknowledged as a promising approach for the remediation of noxious pollutants. The current study was oriented to appraise the performance of modified rice straw for copper adsorption in hand with the optimization of its operational parameters. RSM-based Box-Behnken design was employed to optimize the operational variables encircling temperature, pH, and adsorbent dose. The results elucidated that the generated model exhibited an R-squared of 0.98, reflecting its validity in describing the experimental data well. The optimized conditions for attaining maximum copper adsorption were marked to be a temperature of 37.71 oC, a solution pH of 5.7, and an adsorbent dose of 11.26 g L-1. Under these optimized conditions, the adsorption efficiency was marked to be 86.65 %. The experimental adsorption efficiency under these conditions was noted to be approximately 86.43 %, reflecting the suitability of the RSM-based Box-Behnken design. Conclusively, it can be inferred that acid modified rice straw offers a promising low cost adsorbent for remediation of heavy metals in accordance with the principles of green chemistry.

Evaluation of the Open-Ended Green Chemistry Generic Comparison (GC)2 Prompt for Probing Student Conceptions about the Greenness of a Chemical Reaction.

One key limitation for assessing student knowledge of green chemistry is the lack of readily available assessments capable of eliciting reliable and valid data. Therefore, in this study we sought to evaluate the ability of a previously reported open-ended prompt [J. Chem. Educ.2019, 96 ( (11), ), 2410-2419. DOI: 10.1021/acs.jchemed.9b00277] to probe student conceptions about the greenness of chemical reactions. Responses to this prompt, which we titled the Green Chemistry Generic Comparison (GC)2 prompt, were collected from students enrolled in organic chemistry I and II lecture and laboratory courses (N = 642) and from students enrolled in general chemistry II lecture courses (N = 272). This prompt was found to be sensitive for detecting gains in green chemistry knowledge in pre- and post- conditions. Furthermore, psychometric analysis revealed that, while addressing certain green chemistry principles was well within the students' ability range, other principles exceeded that range. These findings indicate that this prompt provides a rapid and effective method for both measuring student knowledge and eliciting student conceptions of the green chemistry principles.

Alfalfa biomass as a green source for the synthesis of N,S-CDs via microwave treatment. Application as a nano sensor for nifuroxazide in formulations and gastric juice

BackgroundResearchers have investigated different techniques for synthesis of carbon dots. These techniques include Arc discharge, laser ablation, oxidation, water/solvothermal, and chemical vapor deposition. However, these techniques suffer from some limitations like the utilization of gaseous charged particles, high current, high temperature, potent oxidizing agents, non-environmentally friendly carbon sources, and the generation of uneven particle size. Therefore, there was a significant demand for the adoption of a new technology that combines the environmentally friendly aspects of both bio-based carbon sourcing and synthesis technique. ResultsMedicago sativa L (alfalfa)-derived N, S-CDs have been successfully synthesized via microwave irradiation. The N,S-CDs exhibit strong fluorescence (λex/em of 320/420 nm) with fluorescence quantum yield of 2.2 % and high-water solubility. The produced N,S-CDs were characterized using TEM, EDX, Zeta potential analysis, IR, UV–Visible, and fluorescence spectroscopy. The average diameter of the produced N, S-CDs was 4.01 ± 1.2 nm, and the Zeta potential was −24.5 ± 6.63 mv. The stability of the produced nano sensors was also confirmed over wide pH range, long time, and in presence of different ions. The synthesized N, S-CDs were employed to quantify the antibacterial drug, nifuroxazide (NFZ), by fluorescence quenching via inner filter effect mechanism. The method was linear with NFZ concentration ranging from 1.0 to 30.0 μM. LOD and LOQ were 0.16 and 0.49 μM, respectively. The method was applied to quantify NFZ in simulated gastric juice (SGJ) with % recovery 99.59 ± 1.4 in addition to pharmaceutical dosage forms with % recovery 98.75 ± 0.61 for Antinal Capsules® and 100.63 ± 1.54 for Antinal suspension®. The Method validation was performed in compliance with the criteria outlined by ICH. Significance and noveltyThe suggested approach primarily centers on the first-time use of alfalfa, an ecologically sustainable source of dopped-CDs, and a cost-effective synthesis technique via microwave irradiation, which is characterized by low energy consumption, minimized reaction time, and the ability to control the size of the produced CDs. This is in line with the growing global recognition of the implementation of green analytical chemistry principles.

Application of signal processing techniques for the spectroscopic analysis of dolutegravir and lamivudine: a comparative assessment and greenness appraisal

HIV treatment has greatly improved over the years, with the introduction of antiretroviral drugs that target the virus and suppress its replication. Dolutegravir and lamivudine are two such antiretroviral drugs that are commonly used in HIV treatment regimens. Herein, three spectrophotometric methods manipulating ratio spectra were developed for the simultaneous analysis of dolutegravir and lamivudine in their binary mixtures. These methods include mathematical processing stages like ratio difference method or signal processing approaches such as the first derivative of the ratio spectra, and continuous wavelet transform. The developed spectrophotometric methods exploit the characteristic spectral differences between dolutegravir and lamivudine in order to quantify them simultaneously. These methods have shown promising results in terms of sensitivity and selectivity as validated per the ICH guidelines. Moreover, these methods offer a straightforward and economical alternative to more intricate analytical methodologies like high-performance liquid chromatography. By incorporating the analytical eco-scale and AGREE for greenness evaluation of the proposed methods, we can further ensure that these techniques are effective and environmentally friendly, aligning with the principles of green chemistry. This evaluation will provide a comprehensive understanding of the environmental friendliness of these spectrophotometric methods in pharmaceutical analysis.

Photo- and Electrochemical Organic Transformations Involving Radical Pathway: A Retrospection of Our Green-Chemistry-Inspired Synthetic Endeavours

AbstractThis account summarises our recent efforts (2020 to mid-2024) in designing and developing a handful of promising organic transformations for accessing several diversely functionalized biologically relevant organic scaffolds by following the green-chemistry principles with a particular focus on the application of low-energy visible light and electrochemistry. Mechanistic studies of each of these reactions established the involvement of a radical pathway.1 Introduction2 Green-Inspired Organic Transformations2.1 Visible-Light-Driven Organic Synthesis2.1.1 Synthesis of Functionalized Dihydrofuro[3,2-c]chromenones2.1.2 Synthesis of Functionalized 2-(Aryl/alkylamino)-3-(aryl/alkylselanyl)naphthalene-1,4-diones and 2-(Arylamino)-3-(arylthio)naphthalene-1,4-diones2.1.3 Synthesis of Functionalized 6-(Arylthio/arylseleno)benzo[a]phenazin-5-ols2.1.4 Synthesis of Functionalized 3-(Alkyl/benzylthio)-4-hydroxy-2H-chromen-2-ones2.1.5 Synthesis of Functionalized 2-Hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxamides and 2-Hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxylates2.1.6 Synthesis of Functionalized 2-Hydroxyphenylated α-Ketoamides2.2 Electrochemical Organic Synthesis2.2.1 Synthesis of 3-Selenylated/Sulfenylated Derivatives of 2-Amino-1,4-naphthoquinones2.2.2 Synthesis of Functionalized 6-(Arylthio/Arylseleno)benzo[a]phenazin-5-ols2.2.3 Synthesis of Functionalized Alkyl 2-Hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxylates3 Conclusions

Development and Application of a Lignin-Based Polyol for Sustainable Reactive Polyurethane Adhesives Synthesis.

In response to the environmental impacts of conventional polyurethane adhesives derived from fossil fuels, this study introduces a sustainable alternative utilizing lignin-based polyols extracted from rice straw through a process developed at INESCOP. This research explores the partial substitution of traditional polyols with lignin-based equivalents in the synthesis of reactive hot melt polyurethane adhesives (HMPUR) for the footwear industry. The performance of these eco-friendly adhesives was rigorously assessed through Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), rheological analysis, and T-peel tests to ensure their compliance with relevant industry standards. Preliminary results demonstrate that lignin-based polyols can effectively replace a significant portion of fossil-derived polyols, maintaining essential adhesive properties and marking a significant step towards more sustainable adhesive solutions. This study not only highlights the potential of lignin in the realm of sustainable adhesive production but also emphasises the valorisation of agricultural by-products, thus aligning with the principles of green chemistry and sustainability objectives in the polymer industry.

Feasibility of matrix solid-phase dispersion combined with HR-CS FAAS for determination of copper in milk-based infant foods

This study proposes, for the first time, the development of an analytical method using the matrix solid-phase dispersion (MSPD) for extraction of copper from infant formulas and milk-based foods for further determination using high resolution-continuum source flame atomic absorption spectrometry (HR-CS FAAS). MSPD parameters were investigated, and by employing a 0.25 g sample, 0.25 g of diatomaceous earth as a solid support, 1 mol/L HNO3 as the extraction solution, and 1 min of blending, higher agreements with reference values were obtained. The limit of detection of the method was 0.35 µg/g. Accuracy was assessed by comparing the results using the following methods: i) proposed method (MSPD/HR-CS FAAS); and ii) decomposition of samples by microwave-assisted digestion (MAD) and quantification by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS). The MSPD extracts were also quantified using HR-CS GFAAS. No significant difference was found between the results. The agreements ranged from 95 to 103 %, and no significant difference was observed between the results. Copper concentrations ranged from 0.40 to 3.8 μg g−1 using the proposed method, with relative standard deviations lower than 10 %. The proposed method proved to be efficient for the determination of copper in infant formulas and milk powder, offering advantages such quickness, simplicity, low cost, low energy consumption, reduced waste generation (due to the use of an aqueous extraction solution), utilization of materials from renewable sources (diatomaceous earth as a solid support), and minimized analyst exposure when compared to conventional sample preparation methods. These attributes align with the principles of Green Analytical Chemistry.

Green ultrasonic-assisted enzymatic extraction of polysaccharides from Flammulina velutipes residues by response surface methodology

Flammulina velutipes residues, the by-products of Flammulina velutipes industry, cause environmental pollution. The aim of the current work was to evaluate the extraction efficiency of polysaccharides from Flammulina velutipes residues by an ultrasonic assisted snailase enzymatic extraction (UAEE) method, following the principles of green chemistry, mainly solvent and energy saving. The optimized parameters obtained by Response Surface Methodology (RSM) were determined as follows: ultrasonic power at 150 W, extraction time of 90 min, and extraction temperature of 55 °C. The experimental extraction yield (109.54 ± 5.44 mg/g) was closely matched the predicted yield (110.92 mg/g). Polysaccharides from Flammulina velutipes residues (UE-FVRP) had the molecular weight of 170 kDa and a composition comprising 8 monosaccharides, primarily xylose (Xyl, 24.71%), mannose (Man, 17.29%), arabinose (Ara, 11.48%), and galactose (Gal, 15.63%). FT-IR analysis suggested that UE-FVRP likely contained pyranose with α-glycoside bonds. In vitro antioxidant activity assays revealed that UE-FVRP displayed potent DPPH radical scavenging activity and reducing ability. Additionally, UE-FVRP demonstrated the ability to promote the growth of two Lactobacillus strains, indicating its potential as a novel polysaccharide with high in vitro prebiotic properties. Therefore, these findings proposed a novel, green, and efficient extraction method for extracting polysaccharides from Flammulina velutipes residues, highlighting the potential of utilizing Flammulina velutipes residues as a valuable ingredient in both food and feed applications, contributing to the sustainable reuse of agricultural by-products.

The Impact of Lignin Biopolymer Sources, Isolation, and Size Reduction from the Macro- to Nanoscale on the Performances of Next-Generation Sunscreen.

In recent years, concerns about the harmful effects of synthetic UV filters on the environment have highlighted the need for natural sun blockers. Lignin, the most abundant aromatic renewable biopolymer on Earth, is a promising candidate for next-generation sunscreen due to its inherent UV absorbance and its green, biodegradable, and biocompatible properties. Lignin's limitations, such as its dark color and poor dispersity, can be overcome by reducing particle size to the nanoscale, enhancing UV protection and formulation. In this study, 100-200 nm lignin nanoparticles (LNPs) were prepared from various biomass by-products (hardwood, softwood, and herbaceous material) using an eco-friendly anti-solvent precipitation method. Pure lignin macroparticles (LMPs) were extracted from beech, spruce, and wheat straw using an ethanol-organosolv treatment and compared with sulfur-rich kraft lignin (KL). Sunscreen lotions made from these LMPs and LNPs at various concentrations demonstrated novel UV-shielding properties based on biomass source and particle size. The results showed that transitioning from the macro- to nanoscale increased the sun protection factor (SPF) by at least 2.5 times, with the best results improving the SPF from 7.5 to 42 for wheat straw LMPs and LNPs at 5 wt%. This study underscores lignin's potential in developing high-quality green sunscreens, aligning with green chemistry principles.

Preparation of iron nanoparticles mediated by Punica granatum and its application for the treatment of denture stomatitis

Denture stomatitis affects around 50% of denture wearers in certain populations as a prevalent oral mucosal lesion. There has been a high interest in utilizing natural antibacterial composites, such as medicinal plants extracts. Punica granatum, a popular medicinal plant, has various pharmacological applications. In this particular research, iron NPs were formulated by the Punica granatum aqueous extract, following the principles of green chemistry. The study objective was to assess the effectiveness of FeNPs on denture stomatitis. The usual analytical examinations were applied for FeNPs. The FE-SEM results confirmed that the nanoparticles exhibited a spherical morphology, with sizes ranging from 21.6 to 65.8 nm. This clinical trial involved 30 patients who received FeNPs. Over a period of two weeks, the patients were instructed to consume the mouthwash four times per day, with 15–20 drops each time, for a duration of 2–3 minutes. Following the mouthwash, they were advised to refrain from eating or drinking for 0.5 hour. The patients in both classes were instructed to consume the medication at particular times. The erythema and inflammation levels were recorded and assessed at each session using a 6-point scale and a graded blade. Additionally, palatal mucosa mycological samples were collected for culture during each visit. The data revealed a notable reduction in the palatal erythema surface compared to the initial condition in the follow-up visits. This study suggests that FeNPs can effectively reduce the Candida colonies number and the area affected by erythema in the denture stomatitis management.

Cover Picture

The cover image describes a novel and eco‐friendly electrochemical strategy for the electrochemical activation of trifluoromethyl thianthrenium triflate (TT–CF3+OTf−). The technique demonstrates successful trifluoromethylation of a diverse range of imidazole‐fused heteroaromatic compounds without the requirement of external oxidants or catalysts, aligning with the principles of green chemistry. More details are discussed in the article by Yu et al. on page 1679—1685.image

Teachers’ perception and attitude toward the integration of green chemistry principles in the school curriculum

Teachers’ perception and attitude toward the integration of green chemistry principles in the school curriculum

Development of Standard Assessment for Understanding Green Chemistry Principles Based on Unity of Science

Understanding green chemistry is a crucial aspect for chemistry teacher graduates, as it equips them with the knowledge and skills to promote sustainable practices, minimize environmental impact, and inspire the next generation of students to engage in eco-friendly scientific innovation. This research is dedicated to developing a standard assessment for understanding Green Chemistry based on the Unity of Science (UoS), which is grouped into three categories: reagents, reaction processes, and reaction products. The research uses a mixed methods design with a triangulation model. A significant part of the research process is the validation of the feasibility of the instrument developed, which was done by five chemical experts. The multi-rater responses obtained were then analyzed using the feasibility criteria of the processed Rasch results. In the trial process, 40 students from the Chemistry Education program were selected as research subjects. The results showed that the reliability of the questions was 0.87, with an item separation level of 2.54. This reliability value of 0.87 indicates that the developed questions are of excellent quality and can be used as a standard for measuring understanding of Green Chemistry based on Unity of Science.

Mo7O246- and alkyl ammonium based metal organic ionic framework and their protein conjugates: Adsorbent for removal of cationic/ anionic dyes

Herein, we report the removal of organic dyes by metal–organic ionic frameworks (MOIFs) incorporating Mo7O246- and alkyl ammonium ions synthesized via an ion-exchange process in aqueous medium, [CnH2n+1)nN(CH3)3][Mo7O24], where n = 12, 14, 16. These were characterized using powder X-ray diffraction (XRD), UV/Visible spectroscopy, and Fourier-transform infrared (FTIR) spectroscopy techniques. A thermal transition occurring at 300–400 °C attributed to the decomposition of organic moieties analyzed through thermal gravimetric analysis (TGA). Coats-Redfern analysis revealed an activation energy of approximately −1.32763 kJ/mol, suggesting rapid interaction capability of MOIFs with pollutants. The heat capacity found approximately 135 J/K, indicating thermal stability investigated using differential scanning calorimetry (DSC). MOIFs exhibited remarkable adsorption of organic dyes demonstrated through complete removal (100 %) of anionic congo red dye and 88 % of cationic safranin dye. MOIFs functionalized with protein conjugates (MOIF@BSA) were evaluated for their adsorption efficiency on mix dye compared to MOIFs, displaying superior performance with up to 95 % removal of mixed dyes. Kinetic studies employing pseudo-first-order kinetics indicated that the adsorption process is primarily governed by the diffusion of dye molecules within the MOIFs structure. Desorption analysis demonstrated complete recovery of MOIFs, dyes, and solvent, highlighting the environmentally friendly nature of the approach employed, consistent with green chemistry principles.

Towards a zero-waste chemcycling of thermoset polymer composites: Catalyst assisted mild solvolysis for clean carbon fiber liberation and circular coating development

Thermoset materials and their reinforced composites are widely employed in the aircraft, wind energy and construction sectors. Their 3D-crosslinked network and their chemical and physical heterogeneity make them particularly difficult to be recycled. Nowadays, the management of composite scraps and end-of-life waste is still based on landfilling or incineration practices, which are clearly non-compliant with the principles of the circular economy. In this work, a catalysed solvolysis process in mild conditions (T = 180 °C, t = 1–3 h, catalyst 1–7 wt%) was applied for the chemical recycling (chemcycling) of anhydride-cured epoxy resins and their carbon fiber reinforced composites. The selection of the hydroxylated solvents followed thermodynamic considerations (Hansen solubility parameters) and green chemistry principles. The quality of the liberated fibers was studied through thermogravimetric analysis, scanning electron microscopy and single-fiber micromechanical testing, highlighting high surface purity and 100% retention of their pristine mechanical properties (Young's modulus, elongation at break and ultimate strength). The organic recyclates were characterized through gel permeation chromatography, Fourier-transform infrared spectroscopy and chemical titration, and directly reused as hydroxylated binders for the formulation and application of bicomponent polyurethane protective coatings. The resulting coatings were characterized by high chemical resistance (> 100 double rubs at methyl-ethyl ketone test), high surface scratch hardness (3H to 5H), good substrate adhesion (1.5–4 MPa), and excellent optical clarity and surface gloss. These results demonstrate the potential zero-waste reusability of all fractions derived from the chemical recycling of carbon fiber reinforced composites, in line with the principles of the circular economy.

Integrating Green Chemistry and Sustainability Principles to a Secondary Science Curriculum: A Mixed-Methods Needs Assessment

Integrating Green Chemistry and Sustainability Principles to a Secondary Science Curriculum: A Mixed-Methods Needs Assessment

Design and synthesis of LDH nano composite functionalized with trimesic acid and its environmental application in adsorbing organic dyes indigo carmine and methylene blue

This work designed and prepared an organic-inorganic nanocomposite using layered double hydroxide (LDH) inorganic substrate and trimesic acid (TMA) as chelating agent. Subsequently, the synthesized organic-inorganic nanocomposite was assessed using multiple identification methods, including FTIR, EDX, XRD, TGA, and FESEM, and the outcomes demonstrated that the intended structure was successfully prepared. Also, in order to investigate the efficiency of the Mg–Al LDH-TMA nanocomposite as an efficient nano adsorbent, it was used for removal of indigo carmine (IC) and methylene blue (MB) from aqueous solutions. This synthetic nanocomposite showed a high adsorption capacity. The efficiency of the produced nanocomposite in the adsorption of selected dyes was investigated with the help of batch adsorption studies performed in a variety of experimental settings, including dye concentration, adsorbent dose, pH, adsorption temperature and contact time. Furthermore, the produced Mg–Al LDH-TMA nanocomposite exhibits strong stability and can be recycled and reused five times in a row, which is well consistent with the principles of green chemistry.

Sustainable and Biomimetic Methodology for Extraction of High-Value-Added Compounds in Almond Hulls.

Almond trees are the most cultivated nut tree in the world. The production of almonds generates large amounts of by-products, much of which goes unused. Herein, this study aimed to develop a green chemistry approach to identify and extract potentially valuable compounds from almond by-products. Initially, a screening was performed with 10 different Natural Deep Eutectic Solvents (NADESs). The mixture lactic acid/glycerol, with a molar ratio 1:1 (1:50 plant material to NADES (w/v) with 20% v/v of water) was identified as the best extraction solvent for catechin, caffeoylquinic acid, and condensed tannins in almond hulls. Subsequently, a method was optimized by a Design of Experiment (DoE) protocol using a miniaturized extraction technique, Microwave-Assisted Extraction (MAE), in conjunction with the chosen NADESs. The optimal conditions were found to be 70 °C with 15 min irradiation time. The optimal extraction conditions determined by the DoE were confirmed experimentally and compared to methods already established in the literature. With these conditions, the extraction of metabolites was 2.4 times higher, according to the increase in total peak area, than the established literature methods used. Additionally, by applying the multiparameter Analytical Greenness Metric (AGREE) and Green Analytical Process Index (GAPI) metrics, it was possible to conclude that the developed method was greener than the established literature methods as it includes various principles of green analytical chemistry.

Extraction of Chemical constituents from Flaxseeds and Fenugreek seeds by different Extraction methods and screening of their activity

The seeds of fenugreek and flaxseeds are ayurvedic drugs with no side effects that are known to control many diseases. When extracted using harmful chemicals such as petroleum ether, hexane, etc., flaxseed oil and fenugreek oil's had an ability to control blood glucose levels. Hence, we intend to extract these oils using green chemistry principles. Accordingly, we plan to test by using four different methods of extracting flaxseed and fenugreek oil, following green chemistry principles, to determine which yields the most effective results. We used mol inspiration web software to calculate some of the QSAR parameters in this study. Then, using an in vitro method known as DNSA, we screened for anti-diabetic activity with the help of UV. We determined the combined and individual anti-diabetic effects of both oils.