Yield Of Total Flavonoids Research Articles

Response Surface Optimization of the Extraction Process and the Antioxidant Capacity of Total Flavonoids from Microcos Paniculata L.

Ultrasonic-microwave synergistic method was used to extract the total flavonoids from Microcos Paniculata L. To optimize the extraction process, we have conducted single-factor experiments on the total flavonoids yield to provide a basis for analysis. After the results were evaluated, we carried out the response surface method to test the antioxidant properties of total flavonoids in Microcos Paniculata L. The evaluation of antioxidant capacity was done from four dimensions. According to the experiments, the optimal extraction parameters included: 40 mesh particle size, 20:1 liquid/feed ratio (mL/g), 250 W ultrasonic power, 400 W microwave power, 30 min extraction time, and a 60% volume fraction of ethanol. When all the conditions were met, the yield of total flavonoids from Microcos Paniculata L. could reach 6.01%. The total flavonoids from Microcos Paniculata L. could remove DPPH.and ABTS+. At the same mass concentration, the scavenging rates. were as high as 93.14% and 84.40%, respectively. They were close to the scavenging rates of Vc in the positive control group. This proves that the total flavonoids in Microcos Paniculata L. have a good antioxidant ability.

Optimizing the Extraction of Bioactive Compounds (Polyphenols, Lipids, and Alpha-Tocopherol) from Almond Okara to Unlock Its Potential as Functional Food.

Almond okara, a by-product of almond milk production, is rich in bioactive components, such as polyphenols, lipids, and alpha-tocopherol, making it a valuable functional food ingredient. This work aimed to investigate its composition while exploring two main aspects: (i) the impact of extraction time, solid-to-solvent ratio, ethanol concentration, and temperature on polyphenol recovery, and (ii) the quantification of okara's triglycerides (TG) and alpha-tocopherol contents. The polyphenols' optimal extraction conditions were 90 min, a 1:30 solid-to-solvent ratio (w/v), 50% ethanol, and 60 °C. These conditions achieved a total polyphenol yield of 523 mg GAE, tannin yield of 340 mg GAE, total flavonoid yield of 548 mg CE, and a total antioxidant capacity of 779 mg AAE per 100 g dry okara. The Peleg model effectively described the extraction kinetics. Additionally, TG levels, quantified by UHE/LPSFC-APCI-MS, in okara were comparable to those in almonds, and alpha-tocopherol levels, quantified by LC-UV, were 14,400 µg/100 g in almonds and 15,600 µg/100 g in okara. These findings highlight the potential of okara as a valuable resource, with a straightforward, scalable, and cost-effective solid-liquid extraction (SLE) method for polyphenols and a supercritical fluid extraction method for TG, for use in the functional food, nutraceutical, and cosmetic industries.

A novel ultrasound-assisted enzyme extraction method of total flavonoids from Viticis Fructus and processed Viticis Fructus: Comparison of in vitro antioxidant activity

In this study, it is the first that the Viticis Fructus (VF) was used as the raw material for extracting total flavonoids using the ultrasound-assisted enzyme extraction (UAE) method. Response surface methodology was employed to determine the optimal extraction parameters. The optimal conditions were as follows: 60 % ethanol solution as the extract solvent, material–liquid ratio of 1:25, pH value of 4, enzyme addition amount of 1.5 %, enzymatic hydrolysis time of 30 min, enzymatic hydrolysis temperature of 40 ℃, and ultrasonic time of 50 min. Comparing the total flavonoid yield of VF and processed VF (PVF) extracted using different methods, it was observed that UAE resulted in a higher total flavonoid yield compared to traditional ultrasound extraction and enzyme extraction. Additionally, the total flavonoid yield of PVF extracted by all three methods was generally higher than that of VF. The PVF solution extracted by UAE also demonstrated better in vitro antioxidant activity compared to VF. These results suggest that UAE is an effective method to enhance the activity of natural total flavonoids. The study of the physicochemical properties and in vitro antioxidant activity of VF and PVF showed that the total flavonoid yield and antioxidant activity significantly increased after VF stir-frying, indicating that their efficacy can also be enhanced.

Green surfactant and circulating ultrasound coupling extraction of total flavonoids from Cynanchum auriculatum leaves: Parameter optimization, extraction mechanism, and HPLC-MS analysis

This study aimed to devise an integrated green surfactant and circulating ultrasound coupling extraction (GSCUE) approach for extracting the total flavonoids from Cynanchum auriculatum leaves. Single-factor optimization combined with a Box–Behnken design was used to determine the optimal technological conditions, which included an APG0814/MES amount of 5 % (w/v), extraction temperature of 46 °C, ultrasound irradiation power of 509 W, liquid–solid ratio of 30 mL/g, mixing speed of 1000 r/min, and extraction time of 50 min. Under these conditions, the extraction yield of the total flavonoids reached 7.83 mg/g. The HPLC-MS was applied to identify the flavonoid compositions in Cynanchum auriculatum leaves extract. The results showed that flavonoid composition included Gardenin B, Luteolin, Kaempferol, Quercetin, 4′-Methoxy-7-O-beta-D-glucopyranosyl-8,3′-dihydroxyflavanone, Astragalin, Spiraeoside, Rutin, and Kaempferol 3-gentiobioside. Further, to investigate the GSCUE mechanism, plant samples before and after extraction were analyzed by fourier transform infrared spectroscopy, scanning electron microscopy, and contact angle analysis. The results indicate that the functional groups, surface microstructure, and surface wettability of the plant samples all affect the yield of the target active ingredients. The hydrophilic group content on the plant sample surface after GSCUE treatment was higher compared to the case of the untreated samples. Additionally, there was evidence of surface structural collapse and shrinkage, increased surface roughness, and a decreased contact angle due to GSCUE treatment. These results highlight the greater surface wettability of the plant samples, faster solvent penetration, and an effective increase in the total flavonoid yield, indicating the synergistic effect of combining ultrasound with green surfactants for total flavonoid extraction. Overall, GSCUE technology provided a sustainable and efficient approach for extracting the total flavonoids from plant materials.

Designing green and recyclable switchable supramolecular deep eutectic solvents for efficient extraction of flavonoids from Scutellariae Radix and mechanism exploration

A green and recyclable switchable supramolecular deep eutectic solvent (SS-DES) was designed and prepared for effective extraction of flavonoids from Scutellariae Radix. The novel SS-DES has both excellent extraction performance of DES and the host guest inclusion of cyclodextrin, thereby showing superior extraction efficiency and selectivity. The characteristic of polarity switching can endow the SS-DES with achieving homogeneous extraction and rapid two-phase separation, shorting per-treatment time largely. Parameters affecting the extraction performance were investigated by the response surface methodology. The results indicated that the SS-DES showed better extraction yield of total flavonoids (157.95 mg/g) compared with pure DES (135 mg/g) and traditional organic solvent (60 % ethanol, 104.87 mg/g). Moreover, the switching mechanism of SS-DES was characterized by FT-IR and 1H NMR, and the extraction mechanism was studied by density functional theory and molecular docking analysis. After evaluating the ecological impact of the method, the cytotoxicity of SS-DES was investigated and the result displayed that its toxicity was very low or even negligible with the EC50>2000 mg/L. After being adsorbed by macroporous AB-8 resin, the regenerated SS-DES was recycled 5 times and the extraction efficiency still remained above 90 %, indicating the desirable reusability. Therefore, the proposed method was efficient and sustainable, and revealed favorable application prospect for the extraction of bio-active compounds from plant materials.

Natural Deep Eutectic Solvent-Based Ultrasound-Assisted Extraction of Flavonoids from Fagopyrum tataricum Bran

In this study, eleven kinds of flavonoids were identified from F. tataricum bran (FTB) by UPLC-Q-TOF-MS, and HPLC-DAD analysis revealed that four compounds, including rutin, quercetin, kaempferol, and nicotiflorin, were the most significant components. Subsequently, natural deep eutectic solvent-based ultrasound-assisted extraction (NADES-UAE) was employed to extract flavonoids from FTB. Among the six kinds of NADES prepared, choline chloride–ethylene glycol (ChCl-EG) was identified as a promising candidate for extracting flavonoids due to its superior extraction performance. The extraction conditions were statistically investigated using response surface methodology conducted by Box-Behnken design (BBD). The optimal operational conditions were as follows: ultrasonic time 268 s, ultrasonic temperature 76 °C, and liquid–solid ratio 43 mL/g, which resulted in a high total flavonoid yield of 40.29 mg/g. Afterwards, the efficient extraction mechanism of NADES-UAE was comprehensively explored through FT-IR spectra, COSMO model, and microstructural analysis. In conclusion, NADES-UAE extraction is considered a green, efficient, and sustainable method for FTB flavonoids.

Identifying the critical LED light condition for optimum yield and flavonoid of pea sprouts

Light, as an energy source and environmental signal, can significantly impact plant growth, development, and metabolism. This study explored three aspects of light environment, including light quality (different red and blue combination), intensity (9–90 μmol/m2/s), and photoperiod (4–20 h/d) to identify and utilize the optimal light conditions for promoting morphogenesis and the accumulation of phenolic compounds in pea (Pisum sativum L.) sprouts of variety Taiwanxiaobaihua. The results showed that dark conditions and red light promoted the longitudinal growth of pea sprouts, while blue light had an inhibitory effect. The appropriate ratio of red and blue light could positively affect the morphological establishment of pea sprouts, promoting the accumulation of total phenolic and total flavonoid contents and improving the antioxidant properties. Within a certain light range, the total flavonoid content and total flavonoid yield of pea sprouts showed an increasing trend with the light intensity increase and the photoperiod extension. Precise estimation of optimal light parameters was achieved using regression models, the total flavonoid content, total flavonoid yield, and dry matter mass of pea sprouts reached an optimal amount at red/blue light ratios of 0.33, 0.46, and 0.71, at 105.86, 90.00, and 9.00 μmol/m2/s of light intensity and at 32.33, 23.28 and 8.23 h/d of photoperiod, respectively. Specifically, increasing dry matter mass by 1 mg decrease in total flavonoid content by 0.78 mg in pea sprouts under these conditions. The scientifically guided light regulation technologies can improve the yield and quality of sprouts and provide a scientific basis for the sustainable development of the sprout industry.

Content and Yield of L-DOPA and Bioactive Compounds of Broad Bean Plants: Antioxidant and Anti-Inflammatory Activity In Vitro

The broad bean plant contains L-DOPA, a compound that is essential for patients with Parkinson’s disease. However, little has been reported on other broad bean compounds that have beneficial effects on health. The objective was to evaluate plants of four Mexican broad bean varieties to determine the content and yield of total phenolic compounds (TPC), total flavonoids (TF), and L-DOPA, as well as to analyze the flavonoid profile and antioxidant (AA) and anti-inflammatory (AANTI) activity in vitro. Broad bean seeds were sown in the field and plants were harvested 20 days after emergence. The analyses were performed with visible UV spectrophotometry and HPLC. The variety José María produced the highest yield of TPC (9.30 g m−2), TF (8.08 g m−2), and L-DOPA (5.64 g m−2) per unit of area. The highest yields per plant were obtained with the Rojita variety: TPC (0.25 g plant−1), TF (0.21 g plant−1), and L-DOPA (0.17 g plant−1). This variety also had the highest antioxidant (IC50 = 87.68 µg mL−1) and anti-inflammatory (IC50 = 74.40 mg mL−1) activity, which was attributed to the L-DOPA compounds and to rutin and isoorientins, respectively. The flavonoid profile revealed the presence of rutin and isoorientins, which had not been previously detected in the broad bean plant.

Ultrasound-assisted extraction (UAE) of antioxidant phenolics from Corchorusolitorius leaves: a response surface optimization

BackgroundBesides fibre production, Corchorusolitorius is considered a nutritional and medicinal plant in traditional medicine. Its leaves possess different antioxidant compounds and display various biological properties. This study optimized the ultrasound-assisted extraction (UAE) parameters like temperature, time, solvent concentration, and liquid–solid ratio for total flavonoids (TFC) and total polyphenols content (TPC) from leaves employing response surface methodology (RSM).ResultsFindings demonstrated that under the optimized conditions, the highest extraction yield of total flavonoids (7.17 mg QE/g DW) and total polyphenol content (13.92 mg GAE/g DW) were recorded with the ethanol concentration 70.92%, temperature 68.06 °C, liquid–solid ratio 48.80 mL/mg, and ultrasound irradiation time 37.20 min. The optimum value of TFC (6.96 mg QE/g DW) and TPC (13.38 mg GAE/g DW) from the experiment of verification of optimized conditions was close to the predicted value and significantly superior to the conventional heat reflux extraction (HRE). LC–MS and HPLC analysis of the optimized extract from UAE demonstrated the existence of six major phenolic compounds, including chlorogenic acid, isoquercetin, hyperoside, adhyperforin, 1,3-di-O-caffeoylquinic acid, and 3,4-di-O-caffeoylquinic acid. Furthermore, the antioxidant test of the UAE leaves extract revealed an excellent 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+•) and hydroxyl radical scavenging with IC50 values of 226.29, 199.53 and 402.02 µg/mL, respectively, compared to HRE with 336.31 µg/mL, 253.86 µg/mL, 520.08 µg/mL.ConclusionsThe developed optimization method could contribute to the good recovery of natural antioxidants from C. olitorius in the pharmaceuticals and food industries.Graphical

Optimization of Cellulase-Assisted Extraction of Total Flavonoids from Equisetum via Response Surface Methodology Based on Antioxidant Activity

Flavonoids are one of the most essential compounds in various plants. This study used the cellulase-assisted method to extract flavonoid-enriched antioxidants from Equisetum arvense L. (EAL). According to a three-factor and three-level central composite design, the response surface methodology was used to obtain the maximum total flavonoid yield, thereby providing the most potent antioxidant activity of EAL extracts. The results indicated that the optimal condition for the total flavonoid extraction was 0.52% (base substrate) enzyme concentration and enzymolysis for 50.58 min at 49.03 °C. The extraction rate of flavonoids from horsetail reached 4.88 mg/g under these optimal conditions. The yield was 51.23% higher than that from the traditional solid–liquid extraction method. The highest DPPH-scavenging ability of the extracts obtained under 0.50% enzyme concentration and enzymolysis for 49.41 min at 46.59 °C was 77.36%. HPLC results revealed that the antioxidant substances had diverse flavonoids. Thus, the extraction condition was consistent for antioxidant activity and total flavonoids. Therefore, the current study provided an efficient method to extract flavonoid compounds from EAL, facilitating technical support for utilizing the plant.

Process optimization of deep eutectic solvent-based microwave-assisted extraction of flavonoids from Ziziphi Spinosae Semen using response surface methodology

Total flavonoids were extracted from Ziziphi Spinosae Semen (ZSS) by applying microwave-assisted extraction with low eutectic solvent (DES) as the extractant. This study investigated the effect of 21 different components of DES on the yield of total flavonoids in ZSS. The results revealed that the DES system, which consists of choline chloride and lactic acid with a molar ratio of 2:1, achieved the best flavonoid extraction efficiency. Based on the single-factor test, response surface methodology was used to optimize and determine the optimal process conditions for the extraction of total flavonoids from ZSS with deep eutectic solvent. The maximum flavonoids yields were achieved at 36.24 mg/g within the 50% DES water content, a microwave power of 600 W, a microwave time of 60 s, a liquid-solid ratio of 1:28 mg/mL, an extraction time of 66 min, and an extraction temperature of 93 °C. The macroporous resin was used to recover flavonoids from extracts. The DM130 resin showed higher adsorption/desorption performance. The total flavonoids of ZSS were extracted using the recovered DES with a yield of 32.58 mg/g and a high reusability of 89.9%.

Conventional and Enzyme-Assisted Extraction of Total Flavonoids from Rotten Onion (Allium cepa L.)

One of the richest sources of dietary flavonoids is the bulb of the onion (Allium cepa L.), which greatly contributes to the daily intake of flavonoids. This research aimed to optimize the yield of Total flavonoids from Onion Solid Waste (OSW). A comparison was drawn between Conventional and Enzyme Assisted extraction methods in terms of the yield of total flavonoids present in OSW extract. The results showed that the highest TFC were obtained at Time/Temp 60 °C for 180 minutes and Pectinase Conc./Time 2g for 120 minutes for Conventional and Enzyme assisted extraction respectively. The yield of TFC by both methods showed that the yield for both was higher in case of enzyme assisted extraction for T13, i.e., 0.472 mg/g respectively than that for conventional extraction for T4 i.e., 0.352 mg/g.

Chemical Compositions, Extraction Optimizations, and In Vitro Bioactivities of Flavonoids from Perilla Leaves (Perillae folium) by Microwave-Assisted Natural Deep Eutectic Solvents.

Natural deep eutectic solvents (NADESs) have been gradually applied to green extraction of active ingredients. In this study, microwave-assisted NADESs were applied to the extraction of flavonoid compounds from perilla leaves. Through comparative experiments, NADES-3 (choline chloride and malic acid at a molar ratio of 1:1) was found to have the highest extraction efficiency of total flavonoids, including apigenin 7-O-caffeoylglucoside, scutellarein 7-O-diglucuronide, luteolin 7-O-diglucuronide, and scutellarein 7-O-glucuronide by HPLC-MS. The following optimal extraction parameters were obtained based on response surface design: water content in NADES of 23%, extraction power of 410 W, extraction time of 31 min, and solid-liquid ratio of 75 mg/mL, leading to the extraction yield of total flavonoids of 72.54 mg/g. Additionally, the strong antimicrobial and antiallergic activity, inhibition of nitrosation, and antioxidant activity of total flavonoids by using NADESs were confirmed. This new extraction method provides a reference for the further exploration of NADES systems and may be widely used for the green extraction of natural active ingredients.

Extraction and Purification of Flavonoids from Buddleja officinalis Maxim and Their Attenuation of H2O2-Induced Cell Injury by Modulating Oxidative Stress and Autophagy.

Cataracts are an ailment representing the leading cause of blindness in the world. The pathogenesis of cataracts is not clear, and there is no effective treatment. An increasing amount of evidence shows that oxidative stress and autophagy in lens epithelial cells play a key role in the occurrence and development of cataracts. Buddleja officinalis Maxim flavonoids (BMF) are natural antioxidants and regulators that present anti-inflammatory and anti-tumor effects, among others. In this study, we optimized the extraction method of BMFs and detected three of their main active monomers (luteolin, apigenin, and acacetin). In addition, a model of oxidative damage model using rabbit lens epithelial cells induced by hydrogen peroxide (H2O2). By detecting the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), and OH (OH), the expression of autophagosomes and autolysosomes were observed after MRFP-GFP-LC3 adenovirus was introduced into the cells. Western blotting was used to detect the expression of Beclin-1 and P62. Our research results showed that the optimal extraction parameters to obtain the highest yield of total flavonoids were a liquid−solid ratio of 1:31 g/mL, an ethanol volume fraction of 67%, an extraction time of 2.6 h, and an extraction temperature of 58 °C. Moreover, the content of luteolin was 690.85 ppb, that of apigenin was 114.91 ppb, and the content of acacetin was 5.617 ppb. After oxidative damage was induced by H2O2, the cell survival rate decreased significantly. BMFs could increase the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decrease the levels of malondialdehyde (MDA) and OH (OH). After the MRFP-GFP-LC3 virus was introduced into rabbit lens epithelial cells and detecting the expression of P62 and Beclin-1, we found that the intervention of BMF could promote the binding of autophagosomes to lysosomes. Compared with the model group, the level of P62 in the low-, middle-, and high-dose groups of BMF was significantly down-regulated, the level of Beclin-1 was significantly increased, and the difference was statistically significant (p < 0.05). In other words, the optimized extraction method was better than others, and the purified BMF contained three main active monomers (luteolin, apigenin, and acacetin). In addition, BMFs could ameliorate the H2O2-induced oxidative damage to rabbit lens cells by promoting autophagy and regulating the level of antioxidation.

Extraction and separation of flavonoids and iridoids from Eucommia ulmoides leaves using choline tryptophan ionic liquid-based aqueous biphasic systems

The choline tryptophan ionic liquid (IL)-based aqueous biphasic system (ABS) was designed and applied to extract and separate flavonoids and iridoids from Eucommia ulmoides leaves. This ABS possessed a unique viscous layer enriching iridoids that can be directly removed at the interface between the IL-rich and salt-rich phases. The extraction yield of total flavonoids was optimized by RSM to obtain a predicted maximum of 2.91% at the IL concentration of 36.73%, liquid to solid ratio of 38, extraction temperature of 44 °C and extraction time of 105 min. The determined extraction yield of total flavonoids is 2.78% ± 0.12% under revised optimization conditions. The distribution coefficient K and extraction rate E of total flavonoids in the IL-rich phase reach the maximum of 129% and 98.53% at the K 3 PO 4 content of 26% in the ILABS, respectively. The HPLC analysis shows a high content of rutin in the flavonoids precipitate induced by water as an anti-solvent. Aucubin content reaches 15.19% in the intermediate viscous layer enriching iridoids. Hence, the designed process has the potential to be applied to the separation and enrichment of rutin and aucubin from other industrial crops. • [Ch][Try] based ILABS integrate extraction and separation of flavonoids and iridoids from EULs. • The iridoids enriched in the interface can be directly recovered. • Flavonoids with higher rutin content were obtained by precipitation with water as antisolvent.

Using the method of mathematical planning of the experiment in the development of a quality control method of aerva lanata l. herb

Today, among the urgent tasks facing the pharmaceutical science of the Republic of Uzbekistan is the study of introduced medicinal plants. Of the promising plants Erva woolly - Aerva lanata Juss of the amaranth family (Amaranthaceae) deserves special attention. A perennial or biennial herbaceous plant grows in many countries of Africa, Saudi Arabia, India, Indonesia, etc. For the first time, Aerva lanata Juss. was introduced on the territory of the former USSR by the Transcaucasian zonal experimental station VILR (Kobuletti) in the mid-70s, then in Ukraine, Uzbekistan and Kazakhstan. Aerva lanata is a dioecious plant. The flowers of A. lanata are nectariferous. Pollination of Erva woolly occurs under the influence of gravity inside the flower, wind, insects and rainwater. Erva woolly with more than one pollination and seed dispersal mode is able to invade a variety of habitats with different environmental conditions and grow as widespread weeds. Among other Aerva species, A. lanata cultivar has a wide range of pharmacological activities such as sedative, antiulcer, antiasthma, antidiarrheal, antioxidant, antihyperglycemic, antimalarial, hypolipidemic and other activities. It is used as a diuretic, for acute kidney damage, as well as for ulcerative wounds, rheumatism. Given the availability of the raw material base necessary to meet the possible growth in consumer demand and its widespread use in traditional and scientific medicine to create effective, low-toxic drugs intended for the prevention and treatment of diseases of the urinary system, Aerva lanata Juss L. was chosen as the object of research. An important stage in the standardization of the final product is the quality control of the technological process and the raw materials entering the production to obtain the finished product. Particular attention is paid to the method of quantitative determination of one of the active substances or groups of biologically active substances that affect the therapeutic effect of finished pharmaceutical products. It is known that the quantitative determination of the active substance is carried out by its extraction from plant materials. In this regard, the problem arises - finding the optimal conditions for the process of extracting the active substance. In view of this, it becomes necessary to conduct research to determine the optimal conditions for the extraction process. The objective of the research: the use of the mathematical planning method of the experiment for the complete extraction of flavonoids from the herb Aerva lanata. To achieve this objective, the following tasks were defined: – selection of the mathematical planning method of the experiment; – selection of method for quantitative determination of flavonoids amount; – statistical analysis of the obtained results. Optimization of the process of extracting the amount of flavonoids from the herb of Aerva lanata, which is predominant in its raw materials, was carried out using the method of mathematical planning of experiments by Box and Wilson. The optimization problem was reduced to determining the values of technological parameters that ensure the maximum yield of total flavonoids from the plant. As an optimization parameter, Y was taken - the content of the sum of flavonoids in the extract, in % of its content in the raw material. Conclusion. This article presents the results of modeling and optimization of the process of obtaining the sum of flavonoids from the herb Aerva lanata Juss. L. A comprehensive quantitative assessment of the influence of three experimental factors (alcohol concentration, hydromodulus and extraction time) on the yield of the total flavonoids was carried out using the method of mathematical planning of the Box-Wilson experiment. The objective was achieved by building a mathematical model based on the first order regression equation: Y=1.20+0.185X1+0.091X2+0.111X3 The adequacy of this process is shown, a mathematical model and parametric identification of this model are presented. As a result of the statistical analysis of the obtained data, the following optimal conditions for the process of extracting the amount of flavonoids from the herb of Aerva lanata were revealed in the quantitative analysis of raw materials: alcohol concentration - 50%; hydromodule - 1:60; extraction time - 30 min. The maximum yield of the sum of flavonoids was 1.52% by weight of dry raw materials. The resulting mathematical model of the extraction process will allow further optimization of the extraction of compounds of natural origin, taking into account the quantitative influence of each factor.

Effect of Solvent Polarity on Extraction Yield of Total Flavonoids with Special Emphasis to Glabridin from Glycyrrhiza glabra Roots

Different organic solvents (ethanol, dichloromethane, ethyl acetate and acetone) were studied for their effects on the extraction efficiency of glabridin and total flavonoids (TF) from Glycyrrhiza glabra roots. The extract yield of Glycyrrhiza glabra roots was in the range of 3% to 6% following the extraction efficiency in the order ethanol>acetone>ethyl acetate>dichloromethane. A higher extraction yield of TF and glabridin was obtained with dichloromethane, followed by ethyl acetate, acetone and ethanol, indicating that the non-polar solvents help in optimal extraction of TF and glabridin. We also demonstrate for the first time, that the extraction efficiency of the flavonoids is not significantly affected by the use of the recovered solvents except in case of ethanol which reflects that the moisture absorbing capacity of the solvent dictates the extraction efficiency of such compounds. The glycyrrhizin content in all the extract types was rather low (0.1 % to 1%) except for extract prepared with water, where the glycyrrhizin content was ~10% as expected since glycyrrhizin is a polar compound. Interestingly, we observed that ethyl acetate selectively isolated only glabridin with no traces of glycyrrhizin, which is a finding reported for the first time.

A Green Method of Extracting and Recovering Flavonoids from Acanthopanax senticosus Using Deep Eutectic Solvents.

In recent years, green extraction of bioactive compounds from herbal medicines has generated widespread interest. Deep eutectic solvents (DES) have widely replaced traditional organic solvents in the extraction process. In this study, the efficiencies of eight DESs in extracting flavonoids from Acanthopanax senticosus (AS) were compared. Response surface methodology (RSM) was employed to optimize the independent variable including ultrasonic power, water content, solid-liquid ratio, extraction temperature, and extraction time. DES composed of glycerol and levulinic acid (1:1) was chosen as the most suitable extraction medium. Optimal conditions were ultrasonic power of 500 W, water content of 28%, solid-liquid ratio of 1:18 g·mL−1, extraction temperature of 55 °C, and extraction time of 73 min. The extraction yield of total flavonoids reached 23.928 ± 0.071 mg·g−1, which was 40.7% higher compared with ultrasonic-assisted ethanol extraction. Macroporous resin (D-101, HPD-600, S-8 and AB-8) was used to recover flavonoids from extracts. The AB-8 resin showed higher adsorption/desorption performance, with a recovery rate of total flavonoids of up to 71.56 ± 0.256%. In addition, DES solvent could efficiently be reused twice. In summary, ultrasonic-assisted DES combined with the macroporous resin enrichment method is exceptionally effective in recovering flavonoids from AS, and provides a promising environmentally friendly and recyclable strategy for flavonoid extraction from natural plant sources.

Purification, antioxidant activities, encapsulation, and release profile of total flavonoids in Peony seed meal.

As potential biomass resources, biomass waste products have been considered worldwide in recent decades. Peony seed meal (PSM) is a kind of agricultural resource waste containing polyphenols, in particular flavonoids. In this study, the total flavonoids of PSM were extracted and purified by AB‐8 macroporous resin (MR), the antioxidant activities of three extract fractions were evaluated, and the total flavonoids were encapsulated with alginate and chitosan by the complex coacervation method. After purification, the yield of total flavonoids was 11.32% and the content in the product increased to 42.89% ± 2.66. The antioxidant activities of three fractions on ·OH, DPPH, and ABTS assays exhibited the following descending order: ethanol elution fraction (ELF) > ethyl acetate extract fraction (EAF) > ethanol extract fraction (EEF). The single‐factor assay showed that the encapsulated total flavonoid microcapsules (EFMs) were prepared with a chitosan concentration of 10 mg/ml, a sodium alginate concentration of 30 mg/ml, a calcium chloride concentration of 50 mg/ml, a ratio of sodium alginate to total flavonoids of 1:3, a flavonoid concentration of 40 mg/ml, and an encapsulation yield of 80.7%. Most microcapsules are smooth‐faced, spherical and uniform in size ranging from 2 to 3 mm in diameter. In vitro release studies suggested that the EFM was stable at pH 1.2 and dissolved at pH 7.5. The result indicated that the EFM is worthy for the development of functional foods and supplements, and PSM could be a potential resource in the food and pharmaceutical industries.

Comparative Study on Conventional and Microwave-Assisted Ethanol Extraction of Phenolics and Flavonoids from Waste Onion Leaves

This study explored the utilization of waste onion leaves for the extraction of important bioactive compounds known for their health benefits such as phenolics and flavonoids. Conventional solvent (CSE) and microwave extraction (MAE) of flavonoids and phenolics from waste onion leaves using aqueous ethanol as solvent were performed. The effects of different factors such as ethanol concentration (50 %v/v &amp; 80 %v/v), temperature (60 °C &amp; 80 °C for CSE) or power level (10 % &amp; 50 % for MAE), and extraction time (1 hr &amp; 4 hrs for CSE, 10 sec &amp; 60 sec for MAE) on the total flavonoid yield (TFY) yield and total phenolic yield (TPY) were evaluated via a two-level factorial experiment. Results showed that for CSE, ethanol concentration, extraction time and the interactions of the factors significantly affected the TFY (p ≤ 0.05), while all the three factors, ethanol concentration-temperature interaction and ethanol concentration-extraction time interaction significantly affected the TPY (p ≤ 0.05). On the other hand, for MAE, ethanol concentration and power level have significant effects on the TFY (p ≤ 0.05) while the ethanol concentration significantly affected the TPY (p ≤ 0.05). The maximum extractable flavonoid and phenolic yields from the onion leaves were found to be 8.61 mg quercetin equivalent (QE)/g dry weight (DW) and 8.95 mg gallic acid equivalent (GAE) /g DW, respectively. For CSE, high levels of both ethanol concentration (80 %v/v) and low level of extraction time (1 hr) resulted in higher values of TFY (2.63 mg QE/g DW) and TPY (6.15 mg GAE/g DW). For MAE, higher values of TFY (2.98 mg QE/g DW) and TPY (4.24 mg GAE/g DW) were obtained at the high level of ethanol concentration (80 %v/v ethanol), high power level (50 %), and high level of extraction time (50 sec). MAE was found to be a more advantageous extraction method than the conventional one, because of its comparable flavonoids and phenolics recovery at a shorter extraction time.