Extraction Of Active Components Research Articles

Integration of 2,3-butanediol production and extraction of active components from Chinese herbs by Bacillus licheniformis and evaluation of fermentation products in vitro

The aim of this work was to develop an integrated process of 2,3-butanediol production and extraction of active components from Chinese herbs via fermentation, and evaluate their potential as cosmetic ingredients in vitro. A GRAS strain DL2–2 of Bacillus licheniformis was isolated and the fermentation medium was optimized using the ingredients that could be used in cosmetics. Four types of Chinese herbs were added solely or in combination into the fermentation medium to perform 2,3-butanediol production and active components extraction simultaneously. The release of polysaccharides and flavonoids was promoted, and the antioxidant, whitening and antibacterial abilities were improved. The highest antioxidant and antibacterial activity was obtained from the ferment filtrate of Dendrobium devonianum and Gastrodia elata f. glauca, resulting from the highest contents of flavonoids (0.44 g/L) and polyphenols (0.31 g/L), and 42.2 g/L 2,3-butanediol was also produced. The highest polysaccharide concentration was obtained from the ferment filtrate containing Polygonatum kingianum, which exhibited the highest inhibitory effect on tyrosinase (65 %), similar to that of 1 g/L arbutin. Therefore, the filtrate of 2,3-butanediol-Chinese herbal fermentation broth is promising as an ingredient in the production of natural high-value cosmetics.

Control of Solar Photovoltaic Integrated Universal Active Filter Using Artificial Intelligence Technique

This paper organizes, a different technique based on adaptive filtering is proposed for the control of three phase worldwide active power filter with a solar photovoltaic array integrated at its DC bus. Two adaptive filters along with a zero crossing detection method are used to remove the magnitude of fundamental active component of distorted load currents, which is then used in estimation of reference signal for the shunt active filter. This technique enables extraction of active component of all three phases with reduced mathematical computation. The series active filter control is based on synchronous reference frame theory and it regulates load voltage and maintains it in-phase with voltage at point of common coupling under conditions of voltage sag and swell. In this paper An artificial intelligence technique fuzzy logic controller is used. The performance of the system is evaluated on an MATLAB/SIMULINK software under various dynamic conditions such as sag and swell in voltage at point of common coupling, load unbalancing and change in solar irradiation intensity.

Optimization of Extraction Conditions from Gac Fruit and Utilization of Peel-Derived Biochar for Crystal Violet Dye Removal.

Gac fruit (Momordica cochinchinensis Spreng.) is a prominent source of carotenoids, renowned for its exceptional concentration of these compounds. This study focuses on optimizing the extraction of active components from the aril of gac fruit by evaluating the effects of extraction temperature, solid-liquid ratio, and extraction time. The primary objective is to maximize the yield of gac oil while assessing its antioxidant capacity. To analyze the kinetics of the solid-liquid extraction process, both first-order and second-order kinetic models were employed, with the second-order model providing the best fit for the experimental data. In addition, the potential of gac fruit peel as a precursor for biochar production was investigated through carbonization. The resultant biochars were evaluated for their efficacy in adsorbing crystal violet (CV) dye from aqueous solutions. The adsorption efficiency of the biochars was found to be dependent on the carbonization temperature, with the highest efficiency observed for BCMC550 (91.72%), followed by BCM450 (81.35%), BCMC350 (78.35%), and BCMC250 (54.43%). The adsorption isotherm data conformed well to the Langmuir isotherm model, indicating monolayer adsorption behavior. Moreover, the adsorption kinetics were best described by the pseudo-second-order model. These findings underscore the potential of gac fruit and its byproducts for diverse industrial and environmental applications, highlighting the dual benefits of optimizing gac oil extraction and utilizing the peel for effective dye removal.

Optimizing the extraction of active components from Salvia miltiorrhiza by combination of machine learning models and intelligent optimization algorithms and its correlation analysis of antioxidant activity

We extracted Sal B and TIIA from Salvia miltiorrhiza using enzymatic-assisted ethanol extraction. ACONN predicted optimal process conditions. Enzymolysis and alcohol extraction were used, optimizing conditions and evaluating antioxidant activity. ACONN analyzed data and ACO optimized conditions. Lab verification comprehensively evaluated the conditions. The correlation between Sal B, TIIA, and their antioxidant activities was examined. Weights of 0.5739 and 0.4260 evaluated Sal B and TIIA. ACONN had a 97.46% fitting degree. Optimized extraction conditions improved yield and quality, yielding a comprehensive evaluation value of 27.69 with 4.46% average errors. This approach enhances extraction and compound quality. Antioxidant activity strongly correlated with component yield, influenced by extraction conditions. ACONN-optimized extraction improved Sal B and TIIA yield and quality, with potential as natural antioxidants. Integrating machine learning and optimization algorithms in industrial extraction enhances efficiency and environmental preservation.

Studying microscopic characteristics and examination of the factors effect flavonoid contents extracted from Bishop wood (Bischofia javanica Blume) leaves at Lam Dong province

In recent years, the use of natural herbal remedies in disease treatment in Vietnam has been significantly considered. Research on the chemical composition, microscopic characteristics, and extraction of active components from herbal materials play an important role in medicinal applications. This study aims to describe the microscopic features of fresh Bishopwood leaves using a dual staining method, examine leaf powder under a microscope, determine the components using chemical reactions, and investigate the influence of factors such as ethanol concentration, time, temperature, and the ratio of raw materials to solvents on the process of extracting flavonoids from Bishopwood leaves. Through unique chemical reactions, the components of Bishopwood leaves were identified to include flavonoids, phenolics, tannins, steroids, proteins, carbohydrates, and anthranoids. Microscopic examination of fresh Bishopwood leaves and leaf powder under a microscope revealed characteristic structural components including epidermis, stomata, parenchyma, sclerenchyma, fiber bundles, and vascular bundles. The appropriate conditions for extracting flavonoids from Bishopwood leaves were using 50% ethanol as the extraction solvent, a 3-hour extraction time, a temperature of 60 °C, and a raw material-to-solvent ratio of 1 : 30 (g/mL). The research findings serve as valuable information contributing to the identification, standardization, and development of new drugs from local medicinal materials.

Ultra-high pressure-assisted micelles for simultaneous and efficient extraction of two insoluble alkaloids from Camptotheca acuminata seeds

As countries focus more on environmental issues, the development of sustainable green technologies has received increasing attention from researchers. This study aimed to propose a green, low-energy-consumption and high-efficiency extraction method for the simultaneous extraction of insoluble alkaloids from plants at room temperature and provide theoretical basis and data support to solve the problem of poorly soluble analogs. Ultra-high pressure (UHP) assisted eco-friendly micellar media (sodium lauryl sulfonate, SLS) at room temperature were applied to extract two insoluble alkaloids, namely, camptothecin (CPT) and hydroxycamptothecin (HCPT), from Camptotheca acuminata seeds simultaneously. The extraction processes of CPT and HCPT were optimized by single-factor and response-surface methodology. The final extraction rates of CPT and HCPT were 82.68 % ± 1.2 % and 89.02 % ± 1.2 %, respectively. Density functional theory (DFT) was used to simulate the interaction between molecules. The hydrogen bond and electrostatic force between CPT, HCPT and SLS caused the formation of CPT-SLS and HCPT-SLS supramolecules, and folds self-assembled into micelles. The combination of these two forces made SLS more soluble in CPT and HCPT, which resulted in the extraction of active components. In the study of the kinetic model of UHP extraction, the entire process occurred by fast washing and slow diffusion simultaneously, with fast washing as the main step. During the extraction process, the endosperm, embryo and cotyledon of Camptotheca acuminata seeds were broken to extract the target components. Compared with other traditional extraction methods, the proposed method shows higher efficiency and lower energy consumption and provides a high-efficiency, environmentally protective, safe, and cost-saving for strategy for the industrial production of natural products.

Applications of New Generation Solvents for Extraction of Herbal Products Prior to Atomic and Molecular Analysis

In this review, an up to date and current knowledge of some of the green solvents, which includes supercritical fluids extraction (SFE), switchable polarity solvents (SPS), and natural deep eutectic solvents (NADES) are discussed with more emphasis on the extraction of active components of herbal products. Different scientific articles and books have been researched and reviewed to explain the applications of new generation solvents for extraction of herbal products prior to atomic and molecular analysis from the past until now. Currently, the most of techniques used in processing herbal products involve the use of extraction methods. Therefore, trends in extraction methods focuses mainly on finding reasonable solutions that minimizes the use of toxic solvents and allows the usage of renewable and green solvents from natural products, which ensure high quality and safe extracts. In future, SFE is definitely going to be on the industrial scale due to its numerous applications in the large scale especially for herbal, food, cosmetics and pharmaceutical products etc.

Organic-NaH2PO4-H2O aqueous biphasic system for extraction of paeonol from cortex moutan: Solvent selection and mechanism probing

Aqueous biphasic system (ABS) for extraction of active components attracted increasing attention due to advantages of high extraction efficiency and high product purity. However, solvent factors ruling extraction is still unclear. Four new ABSs with different organic solvent were designed for paeonol extraction, and the extraction conditions such as NaH2PO4 concentration, organic solvent fraction, extraction period and temperature were examined with single factor method. The paeonol extraction yield, partition coefficient and paeonol purity with ABSs at optimized conditions were in the order as follows: ABS-THF-EA (33.6 ± 1.5 mg/g) ≈ABS-Ac-EA (33.0 ± 1.3 mg/g) > ABS-EtOH-EA (31.6 ± 1.6 mg/g)≈70 % ethanol (v/v) (31.2 ± 1.4 mg/g) > ABS-THF (28.8 ± 1.0 mg/g) > ABS-Ac (27.6 ± 1.2 mg/g) > ABS-EtOH (25.2 ± 1.2 mg/g), suggesting that replacing fraction of acetone/THF with ethyl acetate (EA) in ABSs could improve paeonol yield. Compositions and solvatochromic parameters for top phase of 12 ABSs were detected. Using LSER model, paeonol yield was strongly correlated to the dipolarity/dipolarizability (π*), hydrogen bond acidity (α) and hydrogen bond basicity (β) of top-phase medium in ABS (r2 = 0.982, n = 12); and partition coefficient was reasonably correlated to π*, α and β (r2 = 0.942, n = 12). Hydrogen-bond interaction and hydrophobicity interaction between paeonol and top-phase medium were crucial for efficient extraction. Solvatochromic parameters can offer guidance to solvent selection in extraction with ABS.

Pistacia vera L. leaves as a renewable source of bioactive compounds via microwave assisted extraction

The production of pistachio in Tunisia generates a large amount of potentially valuable waste, such as leaves, that could be used as source of bioactive compounds. In this work, the extraction of phytochemicals from Pistacia vera L. leaves (male and female) by microwave-assisted extraction (MAE) has been investigated. A response surface methodology (RSM) was used for the optimization of bioactive compounds extraction, where the independent variables were temperature and extraction time, and the dependent variable was extraction yield. Total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH, ABTS, and FRAP) and antimicrobial activity of the extracts obtained at optimal conditions for both leaves were evaluated and compared not only between them, but also with the extracts obtained by maceration. The optimum extraction conditions were 70 °C and 61 °C, and 5.6 and 12 min for male and female leaves respectivily. The best results were achieved for female leaves by MAE with 36% of extraction yield, TPC of 196.35 mg gallic acid equivalents (GAE)/g dry weight (DW), TFC of 83.34 mg catechin equivalents (CE)/g dry weight (DW), and high antioxidant and antimicrobial activities. The evaluation of biological activity of the extracts showed that MAE provides extracts with better antioxidant and antimicrobial capacities then those obtained by maceration. Moreover, UPLC-DAD-ESI-MS was performed to confirm the presence of some phenolic compounds in MAE extracts, such as quercetin, apigenin and myricetin derivatives. The results revealed that MAE is an efficient technique for the extraction of active components from Pistacia vera L. leaves.

Network Pharmacological Study on the Mechanism of Cynanchum paniculatum (Xuchangqing) in the Treatment of Bungarus multicinctus Bites.

Background Bungarus multicinctus is one of the top ten venomous snakes in China. Its venom is mainly neurotoxin-based. Novel antivenom drugs need to be further researched and developed. Objective This study aimed to explore the molecular mechanism of Cynanchum paniculatum in treating Bungarus multicinctus bites based on network pharmacology. Material and methods. The potential active ingredients of Cynanchum paniculatum were screened and their SDF structures were obtained using the PubChem database and imported into the SwissTargetPrediction database, and targets were obtained for the antitoxin effects of Cynanchum paniculatum in the treatment of Bungarus multicinctus bites. The Cynanchum paniculatum-active compound-potential target network and protein-protein interaction network were constructed by using Cytoscape software, and then biological function analysis and KEGG pathway enrichment analysis were performed using the DAVID. Results Seven potential active components (cynapanoside C, cynatratoside B, tomentolide A, sitosterol, sarcostin, tomentogenin, and paeonol) and 286 drug targets were obtained, including 30 key targets for the treatment of bungarotoxin toxicity. The active components mainly acted on PIK3CA, MAPK1, MAP2K1, JAK2, FYN, ACHE, CHRNA7, CHRNA4, and CHRNB2, and they antagonized the inhibitory effect of bungarotoxin on the nervous system through cholinergic synapses and the neurotrophin signaling pathway. Conclusions Cynanchum paniculatum exerts a therapeutic effect on Bungarus multicinctus bites through multiple active components, multiple targets, and multiple pathways. The findings provide a theoretical basis for the extraction of active components of Cynanchum paniculatum and for related antivenom experiments.

Optimization of Ultrasonic-Assisted Extraction of Active Components and Antioxidant Activity from Polygala tenuifolia: A Comparative Study of the Response Surface Methodology and Least Squares Support Vector Machine

Dried roots of Polygala tenuifolia (YuanZhi in Chinese) are widely used in Chinese herbal medicine. These components in YuanZhi have significant anti-oxidation properties owing to high levels of 3,6’-disinapoylsucrose (DISS) and Polygalaxanthone III (PolyIII). In order to efficiently extract natural medicines, response surface methodology (RSM) and least squares support vector machine (LSSVM) were used for the modeling and optimization of ultrasound-assisted extraction of DISS and PolyIII together to determine the antioxidant activity of the extracts obtained from YuanZhi. For the optimal combination of the comprehensive yield of DISS and PolyIII (Y), the Box-Behnken design (BBD) was used to improve extraction time (X1), extraction temperature (X2), liquid–solid ratio (X3), and ethanol concentration (X4). The optimal process parameters were determined to be as follows: extraction time, 93 min; liquid–solid ratio, 40 mL/g; extraction temperature, 48 °C; and ethanol concentration, 67%. With these conditions, the predictive optimal combination comprehensive evaluation value is 13.0217. It was clear that the LS-SVM model had higher accuracy in predictive and optimization capabilities, with higher antioxidant activity and lower relative deviations values, than did RSM. Hence, the LS-SVM model proved to be more effective for the analysis and improvement of the extraction process.

Deep Eutectic Solvents (DESs)-Ultrasonic-Assisted Extraction of Paeoniflorin and Paeonol from Moutan Cortex

Deep eutectic solvents (DESs-)-ultrasonic-assisted extraction technology was used to evaluate and optimize the extraction process of paeoniflorin and paeonol in Moutan Cortex. First of all, 10 kinds of choline chloride-based DESs were selected as potential extraction solvents, and the DES extraction effect of choline chloride: lactic acid was determined to be the best. Then, single-factor experiments were conducted to explore the effects of DES composition (molar ratio, water content, and ratio of material to liquid) and ultrasonic treatment (ultrasonic power, extraction time, extraction temperature, and vortex time) on the yield of paeoniflorin and paeonol in Moutan Cortex. On this basis, the response surface method was used to optimize the process of ultrasonic-assisted extraction of paeoniflorin and paeonol from Moutan Cortex with DESs. The results showed that the optimum process parameters of DESs-ultrasonic-assisted extraction of paeoniflorin and paeonol from Moutan Cortex were as follows: molar ratio of choline chloride to lactic acid was 1 : 2, water content was 30%, ratio of material to liquid was 1 : 30 (g/mL), ultrasonic power was 300 W, extraction time was 33 min, extraction temperature was 50°C, and vortex time was 5 min. Under these conditions, the yield sum of paeoniflorin and paeonol in the obtained Moutan Cortex was 9.279 mg/g. The difference between the experimental value and the theoretical value was 0.333 mg/g. The results showed that the response surface method can simulate and predict the yield of paeoniflorin and paeonol in Moutan Cortex under different extraction conditions, and it was feasible to optimize the process parameters. The results of this study show that DES has great potential to replace traditional solvents in the extraction of active components of the Moutan Cortex. The study on the extraction of active components of traditional Chinese medicine by DES is helpful to expand the scope of the application of DES in traditional Chinese medicine.

Micellar Extraction of Active Components from Spices and Evaluation of the Ce(IV)-Based Reducing Capacity of the Extracts

Micellar Extraction of Active Components from Spices and Evaluation of the Ce(IV)-Based Reducing Capacity of the Extracts

Fabrication of a monolithic adsorbent with multi-sites and its application in the extraction of active components from traditional Chinese medicine formula

A vinylic functionalized covalent organic framework (V-COF) was introduced to the preparation of a porous organic polymer (POP)/V-COF monolithic cartridge, via one-step polymerization reaction in a 50-mm-long and 4.6-mm-inner diameter stainless steel column. The fabricated POP/V-COF monolith was characterized with scanning electron microscope, Fourier transform infrared spectrometer and specific surface area measuring instrument, which indicate that the monolithic material in the cartridge occupies porous structure, multiple functional groups and high specific surface area of 188.2 m2 g−1. The POP/V-COF monolith was used as a solid-phase extraction (SPE) cartridge, which was online combined with an octadecyl-silane analytical column of high-performance liquid chromatography (HPLC) to extract, enrich and detect dihydrotanshinone Ⅰ, cryptotanshinone, tanshinone I and tanshinone ⅡA from traditional Chinese formula of POP/V-COF adsorbent. Furthermore, the POP/V-COF cartridge was used to extract and enrich the bornyl acetate from the Salvia Miltiorrhiza Drink by offline SPE procedure, and the extractive solution was subsequently analysed using capillary-gas chromatography method. These results show that the POP/V-COF SPE cartridge can remove the matrices of the Salvia Miltiorrhiza Drink, and simultaneously can extract the target active components with specific selectivity. Quantitative methodology validation indicates the applicable of this method for determination of the four active components in Salvia Miltiorrhiza Drink with the fabricated online SPE-HPLC. It is worth noting that the present cartridge can be reused for at least 100 times, with the RSD values based on the peak areas of the four components are less than 6.3% (n = 100).

Green extraction of microalgae components for incorporation in food and feed supplements

Microalgae have been long recognized as potential food and feed solution, since they are able to meet the population growth on demand for a more sustainable food and feed, especially with respect to protein production. In addition, bioactive components, such as eicosapentaenoic acid (EPA), with well-known antioxidant and anti-inflammatory properties, can be extracted and incorporated in food supplements. Microalgae cultivation and processing becomes even more sustainable if simultaneously coupled to green technologies for the environmental protection. One of the most promising techniques is the supercritical fluid extraction which allows to extract bioactive compounds without loss of their activity and free from extraction solvents. In this work, a pilot scale supercritical CO2 (ScCO2) extraction plant was exploited for performing the extraction of active components from microalgae biomass potentially usable in the food and the feed sectors. Nannochloropsis gaditana microalga was selected as natural producer of EPA. The extract obtained after ScCO2 tests was enriched of EPA and protein, therefore suitable for food applications. The exhausted biomass, having a high content of carbohydrates and total dietary fiber, might be proposed as feed suppl

High performance liquid chromatographic method for determination of active components in lithospermum oil and its application to process optimization of lithospermum oil prepared by supercritical fluid extraction

紫草提取制备成的紫草油能够预防及治疗婴儿尿布疹、皮肤溃烂、湿疹等多种皮肤疾患,临床应用非常广泛,超临界流体萃取是紫草有效成分提取的优选方法。该文建立了紫草油有效成分的高效液相色谱(HPLC)测定方法,并以紫草油所含的有效成分含量为评价指标,采用三因素三水平正交试验法对紫草超临界流体萃取制备过程中的几个重要因素(萃取压力、萃取温度和CO2流量)进行考察,确定了紫草超临界流体萃取的最佳工艺流程。所建立的HPLC方法如下:Diamonsil C18色谱柱(250 mm×4.6 mm, 5 μm),流动相为含0. 1%甲酸的乙腈-含5 mmol/L甲酸铵的0.1%甲酸水溶液(75:25, v/v),等度洗脱,流速为1 mL/min;进样量为15 μL;柱温为室温;二极管阵列检测器(PAD)检测波长为275 nm。该法可在30 min内同时测定紫草油中的有效成分紫草素、乙酰紫草素、β-乙酰氧基异戊酰阿卡宁、异丁酰紫草素、β,β-二甲基丙烯酰紫草素和2-甲基丁酰基紫草素的含量,方法精密度、准确度、重复性好。在萃取压力23 MPa、萃取温度40 ℃、CO2流量27 L/h这一优化工艺流程下得到的紫草油有效成分含量最高。所建立的HPLC-PAD法简便可行、准确可靠,可用于超临界流体萃取制备紫草油的工艺过程优化和质量控制,也可为紫草及其制剂的质量评价提供参考。优化后的工艺条件能够满足紫草油制备需求,也符合生产实际需求。

Exploration of a ternary deep eutectic solvent for the efficient extraction of plantamajoside, acteoside, quercetin and kaempferol from Plantago asiatica L.

In the present study, ternary deep eutectic solvent-based ultrasound-assisted extraction was developed for the efficient extraction of plantamajoside, acteoside, quercetin and kaempferol from Plantago asiatica L. Six kinds of choline chloride-based ternary deep eutectic solvents (TDESs) were prepared as potential extraction solutions. In order to obtain optimal extraction efficiency, a series of extraction conditions were investigated by single-factor test and orthogonal test. The extraction efficiency of choline chloride/lactic acid/ethylene glycol (ChCl-LA-EG) was much higher than that of other TDESs. ChCl-LA-EG-11 synthesised with choline chloride, lactic acid and ethylene glycol (1:4:2) was considered to have a higher extraction efficiency. The optimal ultrasound-assisted extraction conditions were as follows: water content in ChCl-LA-EG-11, 50%; extraction temperature, 70°C; ratio of solid/liquid, 20 mg/mL; ultrasonic power, 60 W; extraction time, 35 min; pH of the solution, 8. Under the optimal extraction conditions, the extraction efficiencies of plantamajoside, acteoside, quercetin and kaempferol were 3.83 ± 0.41, 4.23 ± 0.45, 0.56 ± 0.15 and 0.19 ± 0.08 mg/g, respectively. The extraction efficiency of the total target components was 9.21 ± 0.63 mg/g, which was much higher than that of conventional solvents (water, methanol, ethanol, 50% methanol, 50% ethanol). The target components were isolated efficiently from the TDES solution by an AB-8 macroporous resin column with a recovery rate of 95.6%. This study demonstrated that TDESs possessed excellent physical and chemical properties and had enormous potential for active component extraction of traditional Chinese medicinal materials.

Investigation into the content change and distribution of active components in Cordyceps sinensis with growth cycle by direct TOF-SIMS detection

Analyzing the content of active components in Chinese medicines is crucial to evaluate their medicinal value and further promote the development of pharmaceutical technology. In this work, Cordyceps sinensis, a precious Chinese medicine, was characterized by time-of-flight secondary ion mass spectrometry (TOF-SIMS) to measure the content change of amino acids, nucleosides, mannitol and ergosterol with its growth cycle. Direct and sensitive detection of these active components in Cordyceps sinensis was realized by TOF-SIMS without tedious pretreatment process, such as repeated extraction and purification. Due to complex metabolic regulation, amino acids, nucleosides, mannitol and ergosterol showed different changing trends with growth cycle of Cordyceps sinensis. We found that the changing trend of the same active substance in different parts of Cordyceps sinensis varied dramatically. For instance, with the growth cycle of Cordyceps sinensis, the content of mannitol maintained steady growth in the stroma, while fell first and rose later in the worm body. In some growth stage, the content of mannitol in the worm body was about 10 times higher than that in the stroma. We provided a systematically analytical method and rich data base for further research of the extraction of active components and artificial cultivation of Cordyceps sinensis in this study. Meanwhile, TOF-SIMS is verified to be a sensitive, efficient and convenient method to characterize active components in traditional Chinese medicines.

Antioxidant Capacity and Total Phenolic and Flavonoid Contents of Methanolic Extracts of Urtica dioica L. by Different Extraction Techniques

In this study, the efficacy of different extraction techniques (maceration, ultrasound-assisted and Soxhlet extraction) on the content of biologically active components in extracts from fresh and dried nettle leaves, and their antioxidant activity were analyzed. Methanol was used as the solvent. Total phenolic content and antioxidant capacity were determined by Folin-Ciocalteu, DPPH and FRAP methods, respectively. High content of total phenolic compounds and high antioxidant activity were recorded in extracts of dried nettle. Extracts obtained from fresh nettle samples showed significantly lower content of analyzed bioactive components and lower antioxidant activity. In the case of all extracts, Soxhlet extraction proved to be the most efficient, and maceration the least efficient extraction technique for isolation of bioactive components from nettle leaves.

Development of an innovative maceration technique to optimize extraction and phase partition of natural products

The active component extraction from plants is the first crucial step in natural product research. For non-targeted extraction with an objective to isolate and characterize as many compounds as possible, the most classical technique, and the simplest to implement, is the Soxhlet extraction; however, it does not allow retrieving all the compounds from the plant (when it does not additionally cause artifacts during long heating process). The second most used technique is the extraction by successive macerations using solvents of increasing polarity. While this method is frequently used, few studies are available to rationalize and optimize it. Furthermore, this extraction technique requires some enhancement mainly for efficiency, environmental and time constraint reasons. Here, we present an innovative method of successive macerations using a mixture of solvents with the aim of simultaneously improving the yield, the partition of the compounds between the different phases and reducing the volume of extraction solvents. Triphasic systems were prepared by mixing five solvents (n-heptane, ethyl acetate, acetonitrile, butan-1-ol, water) in various proportions. To validate this method, the most efficient triphasic system was subsequently used to perform three successive macerations with a polarity gradient on a model plant before being extended to several alpine plants. Our results showed an overall good yield compared to conventional maceration techniques, while improving phase partition and reducing extraction time and volume of solvents.