Efficient Extraction Of Flavonoids Research Articles

Green and efficient extraction of flavonoids from Perilla frutescens (L.) Britt. leaves based on natural deep eutectic solvents: Process optimization, component identification, and biological activity

In this study, an ultrasonic-assisted natural deep eutectic solvent (NaDES) was used to extract flavonoids from Perilla frutescens (L.) Britt. leaves. Of 10 tested NaDESs, that comprising D-(+)-glucose and glycerol exhibited the best total flavonoid extraction rate. Response surface methodology (RSM) was used for extraction modeling and optimization, and the total flavonoid content reached 87.48 ± 1.61 mg RE/g DW, which was a significant increase of 5.36% compared with that of 80% ethanol extraction. Morphological changes in P. frutescens leaves before and after extraction were analyzed by scanning electron microscopy (SEM), and the mechanism of NaDES formation was studied by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, 10 flavonoids were identified by UPLC-Q-TOF-MS. In addition, the NaDES extract had better biological activity according to five kinds of antioxidant capacity measurements, cyclooxygenase-2 (COX-2) and hyaluronidase (Hyal) inhibition experiments. Moreover, the stability test revealed that the total flavonoid loss rate of the NaDES extract after four weeks was 37.75% lower than that of the ethanol extract. These results indicate that the NaDES can effectively extract flavonoids from P. frutescens leaves and provide a reference for further applications in the food, medicine, health product and cosmetic industries.

Efficient Extraction of Flavonoids from Lotus Leaves by Ultrasonic-Assisted Deep Eutectic Solvent Extraction and Its Evaluation on Antioxidant Activities

The discovery of a green extraction solvent for natural plants could promote related research. In this study, deep eutectic solvents (DES) were used as green solvents coupled with an ultrasound-assisted extraction method (UAE) to extract flavonoids from lotus leaves. Thirty-four different DES were performed and choline chloride/urea with 40% water was chosen as the most promising one, and the related parameters in the procedures were optimized, resulting in the highest extraction amount of flavonoids in lotus leaves. D-101 was selected from four macroporous resins to separate the flavonoids from DES. Moreover, DES could be recycled and efficiently reused four times with satisfactory performances. In addition, the lotus leaf flavonoids from the DES extract exhibited antioxidant activities in five kinds of assays including DPPH, ABTS, Fe3+ reducing, FRAP, and Fe2+ chelating. It also showed antibacterial activities on Staphylococcus aureus and Escherichia coli bacterial strains with minimal inhibitory concentrations at 1666 μg/mL and 208 μg/mL, respectively. In the HPLC analysis, the three main components in the DES extract were identified as astragalin, hyperoside, and isoquercitrin. In conclusion, the developed UAE-DES followed by macroporous resin treatment could become an efficient and environmentally friendly extraction and enrichment method for flavonoids from lotus leaves and other natural products.

Optimization of natural deep eutectic solvents extraction of flavonoids from Xanthoceras sorbifolia Bunge by response surface methodology

A green and efficient extraction of flavonoids from Xanthoceras sorbifolia Bunge by using ultrasound-assisted natural deep eutectic solvents combined with response surface methodology. Response surface methodology was used to optimize the extraction process. We aimed to test the scavenging ability of sixteen different NADESs and methanol extracts on DPPH and ABTS free radicals. The optimal extraction solvent was as follows: 1, 4-butanediol-acetic acid. With the best solvent the optimal extraction conditions were as follows: molar ratio 1:3, water content 33%, solid-liquid ratio 1:18 g mL−1 and extraction time 33 min. Under these conditions, the yields of (−)-epigallocatechin, catechin, epicatechin, dihydromyricetin, taxifolin and myricetin were 9.99, 1.38, 11.08, 6.53, 0.84 and 0.54 mg g−1, respectively. A total extraction yield of 30.37 mg g−1 was obtained. The IC50 values of DPPH and ABTS radical scavenging were 3.18 μg mL−1 and 0.51 mg mL−1, respectively. This study suggests that the extraction efficiency and antioxidant activity of 1, 4-butanediol-acetic acid were higher than traditional organic solvent methanol and have the advantages of environmental protection. The experiment provided a new method for the extraction of flavonoids from Xanthoceras sorbifolia Bunge.

Efficient extraction of flavonoids from Polygonatum sibiricum using a deep eutectic solvent as a green extraction solvent

Deep eutectic solvents (DESs) are becoming eco-friendly alternatives for extracting biologically-active substances from natural products. In this study, a DES is used as an eco-friendly solvent to extract flavonoids from Polygonatum sibiricum with the assistance of ultrasound. The antioxidant activity of the extracts was then investigated and the recyclability and reusability of the DES evaluated. Optimizing the DES extraction process produced the following optimum conditions: a betaine–acetic acid molar ratio of 1:4, water content of 30%, solid–liquid ratio of 1: 100 g mL−1, extraction temperature of 50 °C, and extraction time of 30 min. The yield of extracted flavonoids reached 25.4 mg g−1, which is about eight times that achieved using ethanol extraction. Furthermore, the antioxidant ability of the DES extract was more potent than that of the extract obtained using ethanol. Used DES can be efficiently recovered using ultrahigh capacitance porous activated carbon (the recovery yield of DES was around 92% of that of the original DES after ten reuses). In conclusion, DESs can be used to establish green ultrasound-assisted extraction methods for efficient extraction of plant flavonoids.

Natural green deep eutectic solvents-based eco-friendly and efficient extraction of flavonoids from Selaginella moellendorffii: Process optimization, composition identification and biological activity

In this study, ultrasound-assisted natural deep eutectic solvents (DES) were applied to extract total flavonoids (TF) efficiently and eco-friendly from Selaginella moellendorffii. Thirty natural DESs were prepared, of which choline chloride-lactic acid (ChCl-Lac) was selected as the optimal DES. Response surface methodology (RSM) was adopted to obtain the highest TF content from Selaginella moellendorffii by applying ChCl-Lac. A TF content of 5.72 ± 0.13 mg/g was obtained with water content of 24%, extraction power of 260 W, liquid/solid ratio of 24:1 mL/g and extraction time of 43 min. Compared with the ionic liquid extraction and traditional methods, DES-UAE was not only able to save time, but also increased TF content by nearly 2–3 times. Meanwhile, sixteen compounds in S. moellendorffii were identified through UPLC-Q-TOF-MS, and eight compounds were newly discovered. In addition, five biflavonoids in the TF extract were determined simultaneously adopting HPLC under optimal extraction conditions. The results of exploring in vitro biological activities of the TF extract using four antioxidant experiments indicated that the TF extract of S. moellendorffii exhibited potent antioxidant activities. Furthermore, the extract displayed antimicrobial activity against six bacteria, including Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis, Proteus, Brucella and Shigella sonnei. For A549, HCT-116, HT-29, sw1990, HepG2 and HeLa cancer cells, the S. moellendorffii extract possessed apparent inhibition effects on the growth rate. All the results indicated that the DES, as an eco-friendly and efficient solvent, was suitable for extracting total flavonoids from S. moellendorffii.

EXTRACTION OF FLAVONOIDS FROM THE LEAVES OF THE LITTLEWALE LITHOSPERMUM OFFICINALE L. (BORAGINACEAE) USING MICROWAVE ENERGY

One of the possible ways to intensify and increase the efficiency of extraction of biologically active substances from plant materials is the use of microwave radiation. This article presents the results of a study of the influence of parameters of the microwave extraction process on the output of flavonoids from the leaves of the littlewale (Lithospermum officinale L.), belonging to the Boraginaceae family. This plant contains isoquercitrin, which is one of the key flavonoids with the property of tissue regeneration. It was shown that the maximum yield of the target components is achieved with a microwave generator power of 100 W and exposure duration of 2.5 min at a field frequency of 2450 MHz (specific energy consumption is 8.4 kWh/kg). This output is comparable with the output when using conventional convection heating. Microwave radiation provides a 16-fold reduction in the duration of extraction of the sum of flavonoids and an increase in the degree of extraction of isoquercitrin by 23%. The action of microwave energy leads to the destruction of plant tissue, which contributes to a more efficient extraction of flavonoids from plant raw materials.

Extraction of Flavonoids from Scutellariae Radix using Ultrasound-Assisted Deep Eutectic Solvents and Evaluation of Their Anti-Inflammatory Activities.

Deep eutectic solvents (DESs) play important roles in the extraction of active constituents in traditional Chinese medicine. Ultrasound-assisted DES has been used to extract flavonoids from Scutellaria baicalensis. Using the contents of scutellarin, baicalin, baicalein, wogonoside, wogonin, and oroxylin A as quantitative indices, different kinds of DESs have been optimized for extraction and betaine/acetic acid has shown the highest yield. The Box–Behnken response surface method (RSM) was utilized to select the extraction conditions with the highest yields. The optimal extraction conditions were as follows: the molar ratio of betaine/acetic acid was 1:4, the water content was 40%, the solid/liquid ratio was 1:100 g/mL, the extraction temperature was 52 °C, and the extraction time was 23 min. Compared with traditional reflux extraction using 70% ethanol as the solvent, ultrasound-assisted DES has a shorter extraction time and higher yields. Furthermore, anti-inflammatory activities of the two extracts by ultrasound-assisted DES and reflux were compared using RAW264.7 cells and the methyl thiazolyl tetrazolium (MTT) method, and they showed equal anti-inflammatory activities. The results demonstrated that the ultrasound-assisted DES method for extraction of flavonoids from scutellariae radix is simple, green, efficient, and reproducible. This research provides good method guides for the rapid and efficient extraction of flavonoids from natural sources.

Optimizing Extraction of Phenolics and Flavonoids from <i>Solanum ferox</i> Fruit

Various phenolic and flavonoid compounds that are secondary plant metabolites are known to contribute to physiological wellbeing. Extraction efficiency of such compounds from plant sources is dependent on the extraction solvent type and composition, and its pH. In this study, different extraction variables were examined: heating time (20 to 180 min), temperature (60°C, 75°C and 90°C) and pH (2.5, 3.0, 4.0, 5.0, 6.0 and 7.0). Hot water was used in the extraction of dry samples. For phenolics, the most efficient extraction was by using water at 60°C for 180 min, whereby 5.95 mg GA equivalent/dry extract was achieved. The most efficient extraction of flavonoids was achieved with water at 60°C for 150 min, whereby 43 μg Quercetin equivalent/dry extract was obtained. Adjusting the solvent to pH 2.5 increased the yield to 45.3 μg Quercetin equivalent/dry extract.

Efficient extraction of flavonoids from Flos Sophorae Immaturus by tailored and sustainable deep eutectic solvent as green extraction media

In the face of the many shortcomings of conventional organic solvents in the age of green chemistry, deep eutectic solvents (DESs) appear under the spotlight of natural product extraction because of its outstanding advantages. In this study, the extraction of six compounds from Flos Sophorae Immaturus (FSI) with DES-5 (choline chloride/1,4-butanediol) as its topgallant solvent was determined by screening nine DESs. After single factor test and BBD experiment, the optimum conditions of deep eutectic solvent-based microwave-assisted extraction (DES-MAE) were: choline chloride/1,4-butanediol (molar ratio of 1:2) and water content (25%, v/v), time 20 min, microwave power 600 W, temperature 62 ℃, liquid/solid ratio 26 mL/g. The extraction yields of rutin, nicotiflorin, narcissin, quercetin, kaempferol and isorhamnetin were 116.78, 15.01, 23.85, 27.59, 3.09 and 3.33 mg/g, respectively. The kinetic experiment results showed that DES-MAE has significant advantages in the extraction of six compounds. The experimental results showed that DES-MAE could obtain higher yields of target components in a short time than other methods (DES-HRE, DES-UAE and Ethanol-MAE). In addition, the target components were separated from the DES extraction solution, and the recoveries of the target compounds were in the range of 75.5%–84.1%. Therefore, this paper provides a strategy for extraction and separation, the aim of which is to obtain flavonoids from FSI efficiently. Meanwhile, this study can also be used as an alternative to the traditional methods for obtaining bioactive components from plant sources in biochemistry, food industry and pharmaceutical fields.

Flavonoid extraction from Ficus carica leaves using different techniques and solvents

The current study presents the best method for a rapid and efficient extraction of flavonoids from Ficus carica. Dried leaves were extracted using distilled water and ethanol 70% by extraction method of maceration, microwave and stirring. Using of TLC and HPLC techniques, the rutin and kaempferol were detected. For flavonoids extraction ethanol 70% was more efficient than water. The relative concentration of rutin and kaempferol was higher by microwave methods ussing ethanol.

Evaluation of Biologically Active Compounds from Calendula officinalis Flowers using Spectrophotometry

BackgroundThis study aimed to quantify the active biological compounds in C. officinalis flowers. Based on the active principles and biological properties of marigolds flowers reported in the literature, we sought to obtain and characterize the molecular composition of extracts prepared using different solvents. The antioxidant capacities of extracts were assessed by using spectrophotometry to measure both absorbance of the colorimetric free radical scavenger 2,2-diphenyl-1-picrylhydrazyl (DPPH) as well as the total antioxidant potential, using the ferric reducing power (FRAP) assay.ResultsSpectrophotometric assays in the ultraviolet-visible (UV-VIS) region enabled identification and characterization of the full range of phenolic and flavonoids acids, and high-performance liquid chromatography (HPLC) was used to identify and quantify phenolic compounds (depending on the method of extraction). Methanol ensured more efficient extraction of flavonoids than the other solvents tested.Antioxidant activity in methanolic extracts was correlated with the polyphenol content.ConclusionsThe UV-VIS spectra of assimilator pigments (e.g. chlorophylls), polyphenols and flavonoids extracted from the C. officinalis flowers consisted in quantitative evaluation of compounds which absorb to wavelengths broader than 360 nm.

Flavonoids extraction from Alpinia zerumbet (Pers.) Burtt et Smith leaves using different procedures

The current study aims to verify the best method for a rapid and efficient extraction of flavonoids from Alpinia zerumbet. Dried leaves were extracted using distillated water and ethanol 70% by extraction methods of shaking maceration, ultrasonic, microwave and stirring. By the application of TLC and reversed-phase HPLC techniques the rutin and kaempferol-3-O-glucuronide were detected. Ethanol 70% was more efficient for flavonoids extraction than water. No significant yielding variation was verified for ultrasonic, microwave and stirring methods using ethanol 70% (11 to 14%). Relative concentration of rutin and kaempferol-3-Oglucuronide, respectively, was higher by ultrasonic (1.5 and 5.62 mg g-1 dried leaves) and by microwave (1.0 and 6.64 mg g-1 dried leaves) methods using 70% ethanol. Rapid and simplified extraction proceeding optimize phytochemical work and acquisition of secondary metabolites.

Flavonoids extraction from Alpinia zerumbet (Pers.) Burtt et Smith leaves using different procedures

The current study aims to verify the best method for a rapid and efficient extraction of flavonoids from Alpinia zerumbet. Dried leaves were extracted using distillated water and ethanol 70% by extraction methods of shaking maceration, ultrasonic, microwave and stirring. By the application of TLC and reversed-phase HPLC techniques the rutin and kaempferol-3-O-glucuronide were detected. Ethanol 70% was more efficient for flavonoids extraction than water. No significant yielding variation was verified for ultrasonic, microwave and stirring methods using ethanol 70% (11 to 14%). Relative concentration of rutin and kaempferol-3-O-glucuronide, respectively, was higher by ultrasonic (1.5 and 5.62 mg g-1 dried leaves) and by microwave (1.0 and 6.64 mg g-1 dried leaves) methods using 70% ethanol. Rapid and simplified extraction proceeding optimize phytochemical work and acquisition of secondary metabolites.

Flavonoid extraction from Alpinia zerumbet (Pers.) Burtt et Smith leaves using different techniques and solvents

The current study aims to verify the best method for a rapid and efficient extraction of flavonoids from Alpinia zerumbet. Dried leaves were extracted using distillated water and ethanol 70% by extraction methods of shaking maceration, ultrasonic, microwave and stirring. By the application of TLC and reversedphase HPLC techniques the rutin and kaempferol-3-O-glucuronide were detected. Ethanol 70% was more efficient for flavonoids extraction than water. No significant yielding variation was verified for ultrasonic, microwave and stirring methods using ethanol 70% (11 to 14%). The relative concentration of rutin and kaempferol-3-O-glucuronide, respectively, was higher by ultrasonic (1.5 and 5.62 mg g-1 dried leaves, respectively) and by microwave (1.0 and 6.64 mg g-1 dried leaves) methods using ethanol. Rapid and simplified extraction proceeding optimize phytochemical work and acquisition of secondary metabolites.

Flavonoid extraction from Alpinia zerumbet (Pers.) Burtt et Smith leaves using different techniques and solvents

The current study aims to verify the best method for a rapid and efficient extraction of flavonoids from Alpinia zerumbet. Dried leaves were extracted using distillated water and ethanol 70% by extraction methods of shaking maceration, ultrasonic, microwave and stirring. By the application of TLC and reversed-phase HPLC techniques the rutin and kaempferol-3-O-glucuronide were detected. Ethanol 70% was more efficient for flavonoids extraction than water. No significant yielding variation was verified for ultrasonic, microwave and stirring methods using ethanol 70% (11 to 14%). The relative concentration of rutin and kaempferol-3-O-glucuronide, respectively, was higher by ultrasonic (1.5 and 5.62 mg g-1 dried leaves, respectively) and by microwave (1.0 and 6.64 mg g-1 dried leaves) methods using ethanol. Rapid and simplified extraction proceeding optimize phytochemical work and acquisition of secondary metabolites.