Abstract: Over the last two decades, quinoline has emerged as a privileged N-heterocycle with a wide scope of pharmacological properties. It has become an attractive moiety for drug design owing to its fascinating structure and reactivity. Accordingly, various methods have been developed for its synthesis and derivatization. Most known conventional synthesis approaches are operationally complex, require harsh reaction conditions, and tedious workup. They are time- and energy-consuming, low-yielding, and produce a significant amount of side products. In recent years, efforts have been made to reduce reaction times and develop greener routes with higher yields. This review highlights some notable developments for microwave (MW)-assisted synthesis of quinolines. It will cover key examples of MW-assisted one-pot synthesis, multicomponent reactions (MCRs), nanocatalyzed reactions in aqueous media, and other green solvents.
Introduction/Objective: The growing demand for environmentally responsible and resource-efficient processing has accelerated interest in green extraction technologies. This study aimed to develop and optimize a sustainable microwave-assisted extraction (MAE) method using natural deep eutectic solvents (NaDES) for the efficient recovery of antioxidant and enzymeinhibitory phytochemicals from twigs of Otostegia limbata, a medicinal plant of notable ethnopharmacological importance. Methods: A choline chloride–urea-based aqueous NaDES was employed as the extraction solvent. Key MAE parameters, including microwave power, solid–solvent ratio, extraction time, and NaDES concentration, were optimized using response surface methodology (RSM). Total phenolic content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity (RSA), ironchelating activity (ICA), and α-amylase inhibitory activity (AIA) were used as response variables. Artificial neural network (ANN) modeling was applied to evaluate nonlinear relationships, and GC–MS analysis was conducted for phytochemical profiling. Results: Optimal extraction conditions were identified as 770 W microwave power, 30 mL/g solid–solvent ratio, 60-second extraction time, and 30% aqueous NaDES. Under these conditions, TPC (11.44 mg GAE/g DW), TFC (3.93 mg RE/g DW), RSA (2.23 mg AAE/g DW), ICA (52.69 mg EDTAE/g DW), and AIA (53.18%) were achieved. The experimental results closely matched the predicted values, confirming the model's reliability. ANN demonstrated slightly superior predictive accuracy compared to RSM. GC–MS analysis revealed key bioactive compounds, including hardwickiic acid, hardwickiic acid methyl ester, camphor, and thymol. Discussion: The combined MAE–NaDES system effectively enhanced extraction efficiency while reducing solvent toxicity and processing time. The improved predictive performance of ANN highlights its usefulness in modeling complex extraction systems. Conclusion: This study demonstrates that MAE coupled with NaDES is a rapid, efficient, and green extraction strategy for O. limbata, supporting its sustainable utilization in food, nutraceutical, and bioactive ingredient applications.
The introduction of microwave irradiation in organic synthesis has revolutionized traditional synthetic chemistry by enhancing efficiency, reducing reaction times, lowering costs, improving selectivity, increasing safety, and promoting sustainability. Consequently, microwave technology has become indispensable in diverse fields, including the synthesis of peptides, biologically active heterocycles, industrially valuable organic compounds, polymers, and materials science. The use of microwave heating has significantly advanced the synthesis of biologically relevant organic sulfides/thioethers and disulfides compared to conventional synthetic routes. These methods offer shorter reaction times, excellent yields, simple work-up procedures, and the use of green solvents or solvent-free and metal-free reaction conditions, making them more attractive from a green chemistry perspective. Moreover, microwave heating simplifies the solid-phase synthesis of disulfide-rich peptides, making it more viable, selective, and cost-effective. Notably, substantial progress has been made over the past two decades in synthesizing small molecules of both symmetrical and unsymmetrical organic sulfides and disulfides, including disulfide-containing therapeutic peptides, under microwave irradiation. This review provides an overview of recent advancements in the microwave-assisted synthesis of a wide variety of bioactive diaryl and aryl–alkyl sulfides and disulfides, including a disulfide-bridged cycloheptapeptide, along with critical discussions where necessary.
The objective of this review is to explore the role of Micro-wave-Assisted Synthesis (MAS) for the efficient and eco-friendly synthesis of heterocyclic compounds, which are critical scaffolds in drug discovery. The review highlights how MAS aligns with green chemistry principles by reducing reaction time, enhancing yields, and mini-mizing solvent use. It particularly focuses on the synthesis of bioactive heterocycles, including pyrimidines, quinolines, imidazoles, and indoles. A comprehensive literature review was conducted to analyze studies involving MAS in the synthesis of heterocyclic compounds. The methodology involved comparing microwave-based synthetic protocols with conventional methods based on parameters such as reaction time, yield, solvent usage, selectivity, and scalability. Recent technological advances, including con-tinuous-flow microwave reactors and AI-assisted optimization techniques, were also evaluated for their role in overcoming existing limitations. The studies reviewed consistently demonstrated that MAS significantly reduces reac-tion times (from hours to minutes), increases product yields, and improves selectivity compared to traditional thermal methods. For example, several heterocyclic compounds showed yield im-provements of over 20–30% when synthesized under microwave conditions. Additionally, MAS contributed to reduced solvent consumption, supporting environmentally sustainable practices. However, challenges related to industrial scalability and high equipment costs were noted. Microwave-assisted synthesis represents a powerful, sustainable, and time-effi-cient technique for the synthesis of pharmacologically important heterocycles. Despite limita-tions in scale-up and equipment accessibility, ongoing innovations—such as continuous-flow systems and AI-guided optimization—are addressing these barriers. MAS is expected to become increasingly vital in the future of drug discovery, offering a green alternative to conventional synthesis.
Introduction The recycling and utilization of scrapped vehicles has become an extremely important issue all over the world. The purpose of this study is to investigate the effect of ZSM-5 molecular sieve on the microwave pyrolysis of automotive shredder residue.Methods The elemental composition of Automotive Shredder Residue (ASR) was determined through industrial analysis and elemental analysis. Subsequently, thermal gravimetric experiments were conducted using ZSM-5 molecular sieves with different SARs on ASR. The pyrolysis experiments were carried out using a constant-pressure microwave tube furnace at different temperatures and microwave powers, with ZSM-5 molecular sieves of different Si/Al ratios. The products were analyzed by gas chromatography-mass spectrometry.Results The results confirm that ZSM-5 molecular sieve with Si/Al = 15H could effectively reduce the initial activation energy of ASR pyrolysis to 93.278 kJ/mol. Comprehensive analysis determined the optimal experimental conditions to be: ZSM-5 molecular sieve with Si/Al = 15H, a pyrolysis temperature of 750 degrees C, and a microwave power of 600W. The higher yields of both valuable gases and liquid products are achieved under optimal conditions. The combined yield of combustible gases (CH4 and H2) reached 48.66%. In the liquid fraction, aromatic substances constituted 94.44%, with aromatic hydrocarbons alone accounting for 92.59%.Discussion The use of ZSM-5 molecular sieve significantly enhanced the pyrolysis efficiency of ASR by lowering the activation energy and promoting the formation of valuable products. The high selectivity toward aromatic hydrocarbons in the liquid fraction and the substantial yield of combustible gases suggest that microwave-assisted catalytic pyrolysis with ZSM-5 offers a promising route for converting ASR into high-value energy carriers. These findings highlight the potential of ZSM-5 as an effective catalyst for improving product quality and energy recovery from automotive shredder residue.Conclusion This research provides theoretical and experimental references for the catalytic microwave pyrolysis of ASR using ZSM-5 molecular sieves, demonstrating its feasibility and potential for efficient resource recovery from end-of-life vehicles.
Introduction Pyrazoles and chromones represent an important class of heterocyclic scaffolds with extensive applications in medicinal chemistry. A wide range of synthetic methodologies for the construction of these frameworks has been reported in the literature. Among these, microwave- and ultrasound-assisted irradiation techniques have attracted considerable attention for their ability to significantly reduce reaction times and, in many cases, enhance reaction efficiency and yield. The primary objective of this work is to synthesize chromone-pyrazole derivatives using ultrasound- and microwave-assisted methodologies. In the present study, the synthesis of five derivatives of 3-(1,3-Diphenyl-1H-pyrazole-4-carbonyl)-2-methyl-4H-chromen-4-one and five derivatives of 3-(1,3-diphenyl-1H-pyrazole-4-carbonyl)-2-ethyl-4H-chromen-4-one is reported.Methods Five derivatives of 3-(1,3-diphenyl-1H-pyrazole-4-carbonyl)-2-methyl-4H-chromen-4-one were prepared by treating 1-(1,3-diphenyl-1H-pyrazol-4-yl)-3-(2-hydroxyphenyl)propane-1,3-dione with acetic anhydride. Similarly, five derivatives of 3-(1,3-diphenyl-1H-pyrazole-4-carbonyl)-2-ethyl-4H-chromen-4-one were synthesized by reacting the same precursor with propanoic anhydride. Microwave-assisted reactions were carried out using potassium carbonate as a green solid support, whereas pyridine was employed in the ultrasound-assisted protocol.Results The chromone-pyrazole derivatives were successfully synthesized and characterized. The structures of the synthesized compounds were confirmed by melting point determination (in agreement with reported values), TLC, and spectroscopic analyses, including IR, 1H NMR, and mass spectrometry. The results obtained were also compared with those from conventional thermal methods.Discussion The comparison with conventional thermal methods indicates the effectiveness of the proposed approach. The microwave- and ultrasound-assisted procedures offer significant advantages, including the elimination of hazardous or toxic reagents such as phosphorus oxychloride, pyridine, and strong bases like KOH, thereby making the process more environmentally friendly and safer.Conclusion The microwave- and ultrasound-mediated protocols provide clean, efficient, and superior alternatives to traditional thermal methods for the synthesis of the target chromone-pyrazole derivatives. Microwave irradiation enabled completion of the reactions in approximately 6 min, which is significantly faster than the ultrasound-assisted method, which required about 30 min. All target compounds were isolated in excellent yields, exceeding those obtained under conventional heating conditions. Notably, ultrasound-assisted reactions afforded slightly higher yields than microwave-assisted reactions.
Introduction: Microwave ablation (MWA) supplemented with integration of ferrite na-noparticles offers a potential treatment strategy for next-generation cancer treatment that promotes efficient tumor eradication and precise control through intensified localized heating. By utilizing the combined benefits of optimized applicator design and nanoparticle-based study, the present re-search overcomes the drawbacks of conventional MWA techniques. Methods: In this work, different antenna configurations and nanoparticle geometry is explored, and the performance is obtained in terms of specific absorption rate (SAR), temperature distribution, and impedance matching. The coupled thermal and electromagnetic problem is studied by injecting the PEG-coated cobalt ferrite nanoparticles in the tumorous site located in the liver tissue of a human body phantom, and analysis is carried out using the finite element mesh method. Results: It has been observed that among the different configurations of coaxial multi-slot antenna, the 5 slot configuration with spherical-shaped cobalt ferrite nanoparticles, considering shell thick-ness of 5 mm, achieves superior performance and yields a maximum temperature increment of 380 K and localized SAR value of 4200 W/Kg at an optimized power of 10 W. Discussion: The integration of nanoparticles with an optimized antenna design substantially im-proves energy absorption while preserving the spherical ablation profiles required for effective treatment. Both components are essential and synergistic, with the nanoparticles serving as catalytic enhancers that intensify localized heating and thereby strengthen the overall therapeutic perfor-mance of the antenna system. Conclusion: Nanoparticle-mediated MWA treatment strategy presents the potential of a minimally invasive approach and precise temperature control, which is highlighted by the proposed research findings.
Microwave technology is widely used in chemical synthesis and offers unique opportunities that are unachievable with the use of conventional methods of heating. This study aims to review the background, methods, and development in microwave-assisted chemistry and advances with a focus on its increasing relevance in various disciplines. Microwave chemistry promises to greatly decrease the time to complete a reaction from hours to minutes, and increase yield and purity all at once. The rationale for this approach is based on specific patterns in communication, for exam-ple, dipolar polarization and ionic mobility that distinguish the effective transfer of energy to mo-lecular systems. Details of these principles are explored and related to synthetic organic chemistry, materials chemistry, and green chemistry. The assessment of microwave-supported processes demonstrates advances in the preparation of heterocycles, medicinal chemistry, and polymer chem-istry. These refined works not only increase the reaction efficiency but also do all this with the help of excluding hazardous reagents for the environment, which is a great idea concerning Sus-tainable Chemistry. Subsequent advancements of hybrid reactors and the utilization of real-time monitoring enhance the adaptability of microwave technology. Microwave synthetic chemistry in the present context involves nanotechnology and catalysis for the production of multifunctional materials and nanoscale particles. Furthermore, the paper discusses directions in environmental ap-plications, including pollutant degradation and renewable energy systems, so as to demonstrate that the technology is relevant to fighting global issues. However, microwave chemistry comes with certain limitations such as scalability, the problem of non-uniform heating, and the long-term costs of purchasing exotic microwave equipment. This research also presents a detailed description of these limitations and offers rem-edies as discussed by creating adaptive microwave systems for system and computational models for reaction optimization. Finally, this work closes with a discussion of potential perspectives for microwave chemistry, ranging from the concept of interdisciplinary approaches and the inclusion of artificial intelligence in reaction design and process monitoring. Because of its revolutionary capability, microwave chemistry is on the verge of revolutionizing the chemical industry.
The use of microwave irradiation proves to be a promising technique for the rapid and environmentally friendly synthesis of α-aminophosphonate derivatives, ranging from simple to more complex, with diverse structural and pharmacological properties. This review presents an analogous overview of the synthesis of α-aminophosphonate derivatives via the Kabachnik– Fields reaction from dialkyl phosphonates, utilizing microwave irradiation as a versatile and effective method. Compared to classical heating methods, often characterized by longer reaction times, several synthesis steps, lower yields, and less efficient energy transfer, the assistance of microwave irradiation provides significant advantages to the synthesis, including shorter reaction times, higher product yields, and improved purity. Several strategies and reaction conditions for the synthesis of α-aminophosphonates under microwave irradiation have been analyzed and discussed, including the use of different catalysts, solvents, and starting materials.
Microwave-assisted extraction (MAE) is a highly efficient technique used to extract bioactive compounds from plant materials. This method is gaining popularity due to its alignment with the principles of sustainable and green chemistry. Microwave radiation selectively heats polar molecules and their solvents, leading to a rapid increase in temperature within the sample. The MAE method can be performed solvent-free or utilize environmentally friendly solvents (e.g., water, ethanol), thereby reducing environmental pollution. Therefore, the selection of a suitable solvent is the most crucial parameter in an efficient extraction process. Reduced exposure to high temperatures minimizes the degradation of heat-sensitive compounds, resulting in higher-quality extracts. This process significantly reduces extraction time compared to conventional methods, which typically require longer heating periods. MAE typically yields higher amounts of bioactive compounds in shorter times due to improved cell wall disruption and enhanced solvent penetration. MAE improves atom economy by enhancing extraction efficiency, leading to less chemical waste. This technique minimizes the generation of hazardous substances during the extraction process. MAE is considered a green and sustainable technology due to its energy efficiency, reduced solvent usage, enhanced extraction yields, and lower environmental impact.
Microwave-assisted synthesis has emerged as a sustainable and eco-friendly approach for the rapid and efficient production of organic compounds. This technique offers significant advantages over conventional methods, including shorter reaction times, enhanced yields, and improved product purity. The uniform heating provided by microwave radiation is particularly beneficial for the synthesis of heterocyclic compounds and their derivatives. Among these, imidazole derivatives hold great pharmaceutical and biological significance. In light of this, the present review focuses on recent solvent-free, acid-mediated, ionic liquid-mediated, NPs-catalyzed, and metal-catalyzed microwave-assisted methods for the synthesis of these molecules.
1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) is a non-nucleophilic base and belongs to the class of amidine compounds. DBU is involved in the synthesis of a variety of biologically active compounds either alone or in combination with microwaves. The use of microwave (MW) irradiation in organic synthesis is covered under the principles of green chemistry. The DBU in combination with MW has been utilized in the synthesis and/or derivatization of many biologi-cally active five-membered, six-membered, and other heterocycles. This review article discusses the utilization of DBU in combination with MW in the synthesis of compounds, like benzoxan-thones, indoles, benzimidazoles, isoindolin-1-one, isatins, and so on. This article also covers the transformation of group(s) linked to heterocyclic compounds using MW and DBU.
Introduction Microwave-assisted organic synthesis is increasingly sought as a strategy to accelerate organic synthesis while minimizing waste. This study aimed to develop a rapid, scalable, and environmentally friendly protocol for acetylating both primary and secondary alcohols using ethyl acetate as both a solvent and an acetylating agent.Methods Reactions were performed in a microwave reactor (300 W, 120 degrees C, 5 min) with p-toluenesulfonic acid (p-TSA, 0.1 - 0.2 equiv.) as a catalyst. Twenty-six representative alcohols (twenty-one primary and five secondary) were examined under optimized conditions. The conversions were quantified and confirmed using 1H NMR spectroscopy, and ethanol generated in situ was identified as the sole by-product.Results Acetylation of primary alcohols yielded conversions of 67-94%, while secondary alcohols showed 78-91% conversion. The reaction time was 5 minutes.Discussion This protocol surpasses existing methods in both speed and atom economy, with ethyl acetate serving a dual role that obviates the use of halogenated solvents and acetic anhydride. However, tertiary alcohols exhibited no to minimal conversion under these acetylation conditions.Conclusion Microwave-accelerated, p-TSA-catalyzed acetylation using ethyl acetate affords high yields within five minutes and generates minimal waste. The method presents a practical and sustainable alternative for the synthesis of acetate esters in both academic and industrial settings.
Abstract: Silver-based nanoparticles (AgNps) have recently gained traction for versatile applications in biotechnology. However, selecting the suitable synthesis method remains a challenge, as current techniques often suffer from slow reaction rates, high costs, low efficacy, and limited reproducibility. Therefore, it is deemed necessary to choose a method that will offer furtherance of the current technologies to address these drawbacks. One promising approach is microwave (MW) irradiation, which is a one-step, simple, cost-effective, reproducible, and sustainable than conventional methods. MW irradiation enables the rapid formation of highly stable nanoparticles as small as ~2 nm, achieving energy savings of up to 70%. Additionally, using biological agents as reducing agents in MW-assisted synthesis promotes an eco-friendly, low-cost, and straightforward approach. This critical review presents the mechanism behind various biological applications and their efficiencies, anticipating research toward synthesizing high-quality nanoparticles. It encourages adapting the use of MW technology for the facile synthesis of high-quality metal and metal oxide nanoparticles, providing a new way for sustainable applications.
Introduction/Objective The preparation of PtNiCo/reduced graphene oxide (RGO) nanocatalysts with excellent activity and stability using a facile, microwave-assisted, and cost-effective synthetic method is crucial for the commercial application of fuel cells and clean energy technologies. This study examines the impact of varying metal ratios on the catalytic properties of PtNiCo/RGO and compares them with those of Pt/RGO.Methods PtNiCo/RGO nanocatalysts were synthesized via a microwave-assisted hydrothermal method using ethylene glycol as the solvent. Different metal precursor ratios were used to prepare PtNiCo/RGO-1, -2, and -3. The physical and electrochemical characteristics of the synthesized catalysts were analyzed using transmission electron microscopy (TEM), X-ray diffraction (XRD), and various electrochemical tests.Results Among the synthesized samples, PtNiCo/RGO-3 demonstrated the best performance, with an electrochemical surface area (ECSA) of 82.61 m2/g, 2.7 times higher than that of Pt/RGO (30.39 m2/g). It also exhibited a lower CO oxidation potential and better stability during electrochemical methanol oxidation. TEM analysis confirmed a thin nanoparticle morphology with average diameters of 2-5 nm.Discussion The enhanced performance of PtNiCo/RGO-3 is attributed to the synergistic effects among Pt, Ni, Co, and the RGO support. These interactions improved electron transfer, dispersion, and resistance to catalyst poisoning.Conclusion PtNiCo/RGO-3 demonstrates excellent catalytic activity, anti-poisoning characteristics, and durability, making it a promising electrocatalyst for fuel cells and hydrogen production. This work supports the development of cost-effective and efficient clean energy technologies, aligning with the United Nations Sustainable Development Goal 7 (Affordable and Clean Energy).
Background: Resveratrol is a polyphenolic compound found in plants such as Polygo-num cuspidatum, Veratrum nigrum L. and Gnetum montanum Markgr. It has unique functions and biological activities. It has important physiological effects such as anti-cancer, anti-bacterial, lipid-lowering, and prevention of cardiovascular and cerebrovascular diseases. At present, resveratrol is a new type of medicinal and healthcare-active substance, with the potential to develop into a new anti-cancer drug and a new ingredient for healthcare products. Objective: The purpose of this study is to seek the optimal extraction process for resveratrol from the root of Veratrum nigrum L. Methods: The microwave-assisted extraction method (MAE) was used to extract resveratrol from the root of Veratrum nigrum L. and orthogonal experiments were conducted to optimize the extrac-tion process. The results of the microwave-assisted extraction, ultrasonic extraction, and their com-bined use methods were compared with those of the conventional heating reflux method. At the same time, the extraction data of four plants, including Polygonum cuspidatum, Veratrum nigrum L., Gnetum montanum Markgr. and Blueberry, were compared. Results: Under the optimized microwave-assisted extraction conditions, the best process conditions for the root of Veratrum nigrum L were a solid-liquid ratio of 1:20 (g/mL), at a microwave power of 600W, affording an extraction rate as high as 2.7130 (mg/g), within an extraction time of 10 minutes. It is higher than the extraction rate of 2.2911 (mg/g) obtained by the conventional heating reflux method. Conclusion: This study indicates that microwave-assisted extraction is an efficient method with a high extraction rate of resveratrol during short extraction time. It is a green and environmentally friendly extraction technique, and it is recommended for the extraction of active substances such as resveratrol from plants.
Carbon quantum dots (CQDs) have emerged as a promising class of nanomaterials, dis-tinguished by their unique optical and electronic properties, making them ideal candidates for cata-lyzing various organic synthesis reactions. This review provides a comprehensive overview of re-cent advancements in the application of CQDs as catalysts in organic transformations, with a focus on their synthesis, functionalization, and mechanisms of action. CQDs, also referred to as carbon dots (CQDs), are innovative zero-dimensional fluorescent carbon-based nanomaterials that have garnered significant global interest. The advantages of CQDs over traditional catalysts are notewor-thy. They possess a high surface area, which facilitates increased interaction with reactants, and their surface chemistry can be easily tuned to optimize catalytic performance. Additionally, CQDs exhibit excellent stability under a wide range of reaction conditions, ensuring consistent catalytic activity. Their biocompatibility and low toxicity further enhance their appeal, positioning them as environmentally friendly and sustainable alternatives in chemistry. Due to their catalytic applica-tions, CQDs are recognized for their remarkable optical properties, including strong fluorescence and water solubility, which allow them to be utilized in diverse fields, such as bioimaging, biosens-ing, and chemical sensing. Their eco-friendliness and simple synthesis methods make CQDs attrac-tive for applications in nanomedicine, solar cells, drug delivery systems, and light-emitting diodes. The combination of these favorable characteristics positions CQDs as promising candidates for ad-vancing technology across multiple domains, especially in medical and environmental applications. As research continues to uncover new functionalities and applications of CQDs, their role in catal-ysis and other fields is expected to expand, paving the way for innovative solutions to pressing challenges in organic synthesis and beyond.
Background Synthetic dye removal from wastewater poses significant environmental challenges. Metal-organic Frameworks (MOFs), like ZIF-8, offer potential solutions due to their high adsorption capacities. This study has investigated the efficacy of a novel composite material, alpha-Al2O3@ZIF-8, for Methylene Blue (MB) removal. Objective This study aimed to assess the feasibility of alpha-Al2O3@ZIF-8 for MB removal. The synthesis via microwave-assisted methods, physicochemical characterization, adsorption efficiency evaluation, and isothermal/kinetic modeling, has been conducted. Methods The alpha-Al2O3@ZIF-8 composite was synthesized and characterized using SEM, TEM, FTIR, and BET techniques. The adsorption efficiency for MB was tested, and isothermal/kinetic models were applied for mechanistic understanding. Results The composite exhibited robust crystal connections and uniform distribution, with particle sizes ranging from 0.5 to 0.6 mu m. MB adsorption efficiency exceeded 97.8% under optimal conditions. Isothermal and kinetic modeling revealed favorable adsorption behavior, notably with the Langmuir and pseudo-second-order models. Conclusion The composite exhibited robust crystal connections and uniform distribution, with particle sizes ranging from 0.5 to 0.6 mu m. MB adsorption efficiency exceeded 97.8% under optimal conditions. Isothermal and kinetic modeling revealed favorable adsorption behavior, notably with the Langmuir and pseudo-second-order models.
Background: This study evaluates the efficiency of essential oil extraction from Elsholtzia Cristata (EC) using two methods: the classical steam distillation method (CM) and the microwave-assisted extraction method (MM). The focus is on comparing these methods in terms of essential oil yield and assessing the antimicrobial properties of the extracted oils, particularly the antibacterial activity of citral. Objective: The study evaluates which extraction method yields higher essential oil content and bet-ter preserves bioactive compounds, with a focus on the antibacterial activity of citral. It also explores the potential pharmaceutical applications of the essential oil. Methods: Essential oils were extracted from EC using both CM and MM. The essential oil content was measured over different extraction times. Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify the chemical constituents of the oils. Citral isolation efficiency was determined using bisulfite. Antimicrobial testing was performed to evaluate the antibacterial activity of EC essential oils against various bacterial strains. Results: The MM yielded a higher essential oil content (0.47% after 10 minutes) compared to CM (0.4% after 3 hours). GC-MS analysis identified citral A and citral B as the major components of the essential oil. The optimal molar ratio of citral to bisulfite for effective isolation was 1:3, achiev-ing an 86% efficiency. Both EC essential oil and citral exhibited strong antibacterial activity against a range of bacterial strains. Conclusion: The microwave-assisted extraction method demonstrated superior efficiency in ex-tracting essential oils from EC, with higher yields and shorter extraction times compared to the classical method. The significant antibacterial activity of EC essential oil indicates its potential for use in pharmaceutical and healthcare applications.
