Ethanol Volume Fraction Research Articles

Fully 3D-Printed Microfluidic Sensor Using Substrate Integrated Waveguide Technology for Liquid Permittivity Characterization

This paper proposes a fully 3D-printed electromagnetic (EM) microfluidic sensor using rectangular substrate integrated waveguide (SIW) for liquid complex permittivity characterization. The proposed microfluidic sensor is fabricated with a novel additive manufacturing process in which dielectric and conductive inks are simultaneously 3D-printed, allowing high print quality, rapid prototyping, and arbitrary geometry. The fabrication process removes the need for post-printing sintering and cleaning steps that require harmful chemicals. The sensor structure is composed of upper and lower metal plates and a series of cylindrical metal side vias. Since the electric field is high at the center of the SIW cavity in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit {TE}_{101}$ </tex-math></inline-formula> mode, a cylindrical dielectric sample container in the form of a microwell is built into the center of the SIW cavity to maximize the perturbation of the liquid under test (LUT). The application of LUT samples to the microwell results in a change in the resonance frequency and peak attenuation from which the LUT sample is characterized. Ethanol-water mixtures are used as LUTs for validation. The proposed sensor has been verified numerically and experimentally, reducing the resonant frequency from 3.750 GHz to 3.862 GHz by increasing the ethanol volume fraction from 0% to 100%. The sensor showed good sensitivity of 0.345% and a stable frequency change was observed over five measurement repetitions. To the best of our knowledge, this article presents the first fully 3D-printed SIW microfluidic sensor and demonstrates its ability to detect and characterize the liquid complex permittivity.

Evaluation of the matrix effect in the gas chromatographic determination of methanol in alcohol products

The effect of matrix components on the results of gas chromatographic determination of methanol in samples of alcoholic and alcohol-containing products was studied using a modified internal standard method for quantitative calculations. Ethanol, which is the main component of alcoholic products was used as an internal standard. The matrix effect can be attributed to the presence of ethanol in various contents, and volatile and non-volatile impurity components characteristic of different kinds of drinks. The matrix effect was evaluated by the spike test in the study of 24 samples of alcoholic and alcohol-containing products with a volume fraction of ethanol from 6.5 to 96.6%. All samples were subjected to distillation: the initial samples and distillates were analyzed at a low sugar content; whereas at a high sugar content, only distillates were analyzed. It is shown that the effect of matrix components on the results of the determination of methanol by the proposed method is statistically insignificant. The developed method is characterized by lower financial, material, labor and time costs compared to the current technical regulatory legal acts of the EAEU, China, India, the EU, USA and Mexico. Validation of the method can be performed on the basis of data regularly obtained by the laboratory during routine study of alcoholic products, without using any additional reagents, equipment and additional measurements. Moreover, the method has good prospects for standardization at the interstate and international levels, i.e., in the framework of the activities of the Euro-Asian Council for Standardization, Metrology and Certification (EASC) and the authoritative International Organization of Vine and Wine (OIV).

RETURNABLE BAKING WASTE — A NEW TYPE OF RAW MATERIALS FOR DISTILLATES PRODUCTION (PART IV. SPIRIT DRINK)

A distillate is a basis for the blend of a spirit drink. Distillate ripening is necessary to stabilize the physicochemical composition and achieve certain flavor characteristics. Softened water is the second ingredient of the spirit drink blend in terms of volume. The mineral composition of water influences the consumer properties of a drink. The aim of this work is to reveal factors that influence quality indicators of a spirit drink from a new type of a raw material. The objects of the research were the samples of the distillate from baking waste, commercial batches of softened water and experimental blends of a spirit drink. The authors determined the volume fraction of ethanol, organoleptic characteristics and mass concentration of the main volatile components by the gas chromatography method in the objects of the research. It was established that upon distillate ripening, the most intensive oxidative processes occured in a period of 10 to 20 days. This led to an increase in the acetaldehyde concentration by 6–27% depending of a raw material type. At the same time, an increase in the mass concentration of ethyl acetate by 15 to 30%, as well as the total concentration of ethyl caproate, ethyl caprate, ethyl caprylate by 27–38% was observed. An effect of the strength of the spirit drink on its organoleptic characteristics was revealed. The mineral composition of the soften water samples prepared by the method of ion exchange and reverse osmosis was studied. Based on the analysis of the taste and aroma profiles of spirit drinks, an effect of the concentration and ratio of mineral salts in water on product quality characteristics was shown. The authors recommend the optimal duration of distillate ripening before blending — not more than 20 days, the blend strength 40–42% vol. The necessity to use soften water prepared by the method of ion exchange or reverse osmosis with the controlled content of ions of calcium (not more than 9 mg/dm3), sodium (not more than 60 mg/dm3), sulfates (not more than 65 mg/dm3) and hydrogen carbonates (not more than 80 mg/dm3) for blending was substantiated.

Optimization of Ultrasonic-Assisted Extraction of Chlorogenic Acid from Tobacco Waste.

Using tobacco waste as raw material, the ultrasonic-assisted extraction of chlorogenic acid was optimized by response surface methodology (RSM). After repeated freezing and thawing of tobacco waste twice, the effect of pH value, ethanol volume fraction, temperature and extraction time on the extraction rate of chlorogenic acid was investigated by a single factor experiment. On the basis of this, the factors affecting the yield of chlorogenic acid were further optimized by using RSM. The optimum extraction conditions for chlorogenic acid were set at pH = 4.1, ethanol volume fraction was 49.57% and extraction time was 2.06 h. Under the above conditions, the extraction rate of chlorogenic acid could reach 0.502%, which was higher than traditional extraction and unpretreated ultrasonic extraction. All these results can be used as a reference for the extraction of effective ingredients in tobacco waste.

Characterization of botanical origin of selected popular purple Eleutherococcus tea grown in Yunnan province of China and quantification of Its anthocyanins using spectrophotometric method

Purple Eleutherococcus is a selected plant grown in high mountain in Puer region of Yunnan province, which is a rich source of anthocyanins with great potential as local vegetables and tea. However, the unknown botanical origin of purple Eleutherococcus restricted its edible value. Our objectives were to identify the botanical origin of purple Eleutherococcus by DNA marker combined with the morphological characteristics, optimaze the extration method of anthocyanins by orthogonal experiment method and determine the contents of anthocyanins in purple Eleutherococcus tea. The results revealed that the purple Eleutherococcus was more closely related to Eleutherococcus simonii through comparing the sequence alignment of ITS2. Combined with the morphological characteristics of plants, purple Eleutherococcus was finally identified and classified into Eleutherococcus simonii. Through orthogonal experiment, the optimal extraction conditions of anthocyanins from purple Eleutherococcus leaves were determined: the volume fraction of ethanol was 60%, the pH of ethanol solution was 3, and the water bath temperature was 60 °C. The ultrasonic extraction was conducted for 30 min. Our study provides scientific theoretical basis for the industrial extraction of anthocyanins and provides reference value for the further development of purple Eleutherococcus in Puer region of Yunnan province in China.

Extration, identification and stability ananlysis of anthocyanins from organic Guizhou blueberries in China

Guizhou Majiang organic blueberries from China are a prevalent fruit in the health industry and have high anthocyanin contents. This study used the ethanol extraction method, ultrasonic-assisted extraction, AB 8 macroporous resin adsorption purification, and the addition of 3% citric acid to extract anthocyanins, and through single-factor tests and orthogonal tests, the optimum extraction conditions of anthocyanins from blueberries was determined. The optimal extraction conditions were as follows: the extraction temperature was 40 °C, the ethanol volume fraction was 80%, the solid-liquid ratio was 1:10, the ultrasonic extraction time was 60 min, and the extraction amount was 2.56 mg/g. Anthocyanins were identified by HPLC, and the effects of storage conditions on their contents were investigated. K+, Cu2+, and Fe2+ had little influence on anthocyanin contents, while hydrogen peroxide had a highly destructive effect. With increasing illumination time, the retention rate of anthocyanins decreased gradually; the higher the temperature was, the stronger the damaging effect on anthocyanin contents, and the appropriate storage temperature was determined to be -4 °C or below. The absorbance was the highest when pH =2. Taken together, the results of our study revealed the optimal extraction process and appropriate preservation conditions of anthocyanins from organic Guizhou blueberries.

Applicability of Saccharomyces cerevisiae Strains for the Production of Fruit Wines Using Cocoa Honey Complemented with Cocoa Pulp.

SUMMARYResearch backgroundCocoa honey and cocoa pulp are both highly appreciated fruit pulp, but until now, cocoa honey has been less processed than cocoa pulp. In this work, we investigate the applicability of Saccharomyces cerevisiae strains to ferment cocoa honey complemented with cocoa pulp to obtain fruit wines and improve cocoa honey commercialization.Experimental approachThe strain, previously isolated from cachaçaria distilleries in Brazil, was selected based on its fermentation performance. The following conditions for fermentation with S. cerevisiae L63 were then studied: volume fraction of cocoa honey (φCH) complemented with cocoa pulp, sucrose addition (γsuc), temperature (t) and inoculum size (No). The best conditions were applied in order to obtain fermentation profiles.Results and conclusionsS. cerevisiae L63 (No=107–108 cell/mL) is capable of fermenting φCH=90 and 80% for 24 or 48 h with γsuc=50 and 100 g/L at t=28–30 °C resulting in wines with ethanol volume fractions from 8 to 14%. Additionally, the wine produced from φCH=90% had lower residual sugar concentration (<35 g/L) than the wine produced from φCH=80% (~79 g/L) which could be classified as a sweet wine. In general, S. cerevisiae L63 resulted in a similar fermentation performance as a commercial strain tested, indicating its potential for fruit pulp fermentation.Novelty and scientific contributionSaccharomyces cerevisiae L63 can ferment cocoa honey complemented with cocoa pulp to produce fruit wines with good commercial potential, which may also benefit small cocoa producers by presenting a product with greater added value.

The inhibitory effects of selenium nanoparticles modified by fructose-enriched polysaccharide from Codonopsis pilosula on HepG2 cells

Ethanol volume fraction of 80% was widely applied for polysaccharides precipitation from Codonopsis pilosula water-leach liquor, while few researches focused on the dissolved components in 80% alcohol solution. Selenium nanoparticles presented strong biological activities with low toxicity, but the poor stability limited the practical applications. This study isolated a C. pilosula polysaccharide from the supernate after 80% ethanol precipitation, which was used as surface decorator for nano-composites preparation, and then the structural performance, storage stability and inhibitory mechanism on HepG2 cells were investigated. Results showed that the C. pilosula polysaccharide was mainly composed of fructose and glucose (molar ratio of 2.68:1.00) with average molecular weight of 3.21 × 103 Da. Additionally, the nano-composites were successfully prepared under Na2SeO3 to polysaccharide (2.0 mg/mL) ratio (w:w) of 1:20, and exhibited homogeneous distribution with an average particle size of ~ 75 nm and superior stability at 4 °C for at least 35 days. Besides, the nano-composites effectively inhibited HepG2 cells proliferation dose-dependently, and induced the mitochondrial dysfunction via improving Bax expressions and descending Bcl-2 expressions, resulting in the release of mitochondrial cytochrome c to cytoplasm and the activation of caspase-9 / − 3, thereby promoting cells apoptosis. These results would effectively improve utilization rate of C. pilosula and provide theoretical foundation for clinical applications of the composite in hepatoma-bearing patients.

Extraction, isolation and identification of an enzymatic browning product from fresh white salted noodles

An enzymatic browning product (EBP) of fresh white salted noodles (FWSNs) was extracted, purified, isolated and identified. The optimum parameters of extraction were as follows: volume fraction of ethanol 70%, solid-liquid ratio 1 : 10 (g: mL, samples: ethanol solution), extraction time 10 days (20 °C). In the purified process, protein (99.86%) and carbohydrates (69.50%) impurities were removed from the crude extract using Sevag method, dialysis method and AB-8 macroporous resin column. The purified EBP was separated using 20% (v: v) methanol solution in a C18 chromatographic column. A monomer of EBP was isolated by high-performance liquid chromatography. Nuclear magnetic resonance and infrared spectroscopy analysis showed that the EBP monomer was 2-hydroxyindole-3-propylamine. This was the first time in the literature that 2-hydroxyindole-3-propylamine was found in the EBP of FWSNs. It would lay a material foundation for investigating the origin of EBPs and the revealing enzymatic browning mechanism of FWSNs.

An efficient approach for simultaneously obtaining oil and epigoitrin from Orychophragmus violaceus seeds by microwave-mediated immiscible binary solvent extraction

Microwave-mediated immiscible binary solvent extraction (MIBSE) was applied to simultaneously extract oil and epigoitrin from Orychophragmus violaceus seeds. The upper phase of n-hexane was used to obtain oil, and the lower phase of ethanol solution was used to obtain epigoitrin. Factors potentially affecting the yields of oil and epigoitrin were systematically investigated. The optimum conditions were an ethanol volume fraction of 65%, liquid–solid ratio of lower-phase of 20 mL/g, liquid–solid ratio of upper-phase of 12 mL/g, microwave irradiation power of 393 W, and microwave irradiation time of 29 min. The actual yields of oil and epigoitrin were 34.08% ± 1.38% and 11.86 ± 0.47 mg/g, respectively. GC–MS analysis illustrated that the seed oils obtained by MIBSE and Soxhlet extraction exhibited similar fatty acid compositions. The separated epigoitrin was determined by HPLC analyses, which obtained a purity of 91.25% ± 3.83%, follwed by NMR determinations.

Influence of ethanol blending ratios on in-cylinder soot processes and particulate matter emissions in an optical direct injection spark ignition engine

Soot volume fraction distribution of ethanol blended fuels (ethanol volume fraction 0%, 20%, 40% and 60%, named as E0, E20, E40 and E60) were measured in an optical direct injection spark ignition (DISI) engine by combined laser induced incandescence (LII) and two-color (2C) method. Exhaust particulate matter (PM) emissions were measured by a Combustion DMS500 Fast Particulate Analyzer. For DISI engines, pool fire and the resulting diffusion flame are the main sources of soot in the cylinder. Choosing a suitable measurement plane and detection time, laser induced incandescent can be used to quantitatively measure the soot concentration produced by the pool fire. This research explores the effect of ethanol blending on engine particulate matter by comprehensively analyzing the soot process in the cylinder and exhaust particulate emissions. According to the two-dimensional quantitative soot volume fraction results, the maximum average soot volume fraction of the same fuel on the 10 mm plane is greater than the 5 mm plane; on the same plane, E20 shows the highest soot concentration compared to the other fuel blends which could be the physical properties of the ethanol become apparent. For exhaust particle emissions, ethanol can significantly reduce the total particle number and accumulation mode particle number. E0, E40 and E60 show fairly similar behavior between the exhaust particle emissions and the soot-LII imaging measurements. For E20, however, this is in poor agreement when comparing the soot-LII imaging results to the results of exhaust particle emission measurements.

Optimization of Extraction or Purification Process of Multiple Components from Natural Products: Entropy Weight Method Combined with Plackett-Burman Design and Central Composite Design.

In this paper, the optimization of the extraction/purification process of multiple components was performed by the entropy weight method (EWM) combined with Plackett–Burman design (PBD) and central composite design (CCD). We took the macroporous resin purification of Astragalus saponins as an example to discuss the practicability of this method. Firstly, the weight of each component was given by EWM and the sum of the product between the componential content and its weight was defined as the comprehensive score, which was taken as the evaluation index. Then, the single factor method was adopted for determining the value range of each factor. PBD was applied for screening the significant factors. Important variables were further optimized by CCD to determine the optimal process parameters. After the combination of EWM, PBD and CCD, the resulting optimal purification conditions were as follows: pH value of 6.0, the extraction solvent concentration of 0.15 g/mL, and the ethanol volume fraction of 75%. Under the optimal conditions, the practical comprehensive score of recoveries of saponins was close to the predicted value (n = 3). Therefore, the present study provided a convenient and efficient method for extraction and purification optimization technology of multiple components from natural products.

Cononsolvency of Poly[2-(methacryloyloxy)ethyl phosphorylcholine] in Ethanol-Water Mixtures: A Neutron Reflectivity Study.

Molecular mechanisms underlying the cononsolvency, a re-entrant coil-to-globule-to-coil conformational transition of polymer chains in mixtures of two good solvents, of poly[2-(methacryloyloxy)ethyl phosphorylcholine] (PMPC) in ethanol-water binary mixtures were complementarily investigated. This was accomplished by following a statistical mechanical model for competitive hydrogen bonding combined with the cooperative solvation concept as well as neutron reflectivity (NR) experiments employing contrast variation in the cononsolvents. The experimental re-entrant aggregation of the PMPC chains in ethanol-water mixed solvents, obtained on the basis of turbidity was accurately reproduced by theoretical calculations. The calculation proved the relatively strong cooperativity of ethanol and the preferential interaction of water, while the total coverage of solvents was the lowest at an ethanol volume fraction (fethanol) of 0.90. At this level, the cononsolvency was the most significant, and the collapsed PMPC chains were solvated with more water than the bulk mixed solvent. The ethanol-water cononsolvency for the PMPC brushes on a planar silicon wafer was investigated by NR experiments, and the solvent composition involved in the collapsed PMPC brush was addressed according to the contrast variation study with mixed solvents of water, deuterium oxide, ethanol-d5, and ethanol-d6. The collapsed PMPC brushes at fethanol = 0.90 contained more water than the bulk solvent. The preferential distribution of water in the collapsed PMPC brush was consistent with the simulation results. Therefore, the molecular mechanism for the cononsolvency of PMPC in ethanol-water mixed solvents based on competitive hydrogen bonding coupled with cooperative solvation was experimentally rationalized.

Optimization of Ultrasonic-assisted Extraction Process of Flavonoids from Damiana by Response Surface Methodology and Its Antioxidant Activity

The purpose of this study was to determine the optimal extraction process conditions for flavonoids from damiana. Taking the extraction rate of flavonoids as an indicator, the effects of factors such as ultrasonic time, temperature, ultrasonic power, and material-to-liquid ratio on the extraction rate of damiana flavonoids were investigated through experiments. Through response surface tests, a regression mathematical model was established and variance analysis was performed to determine the best conditions for extracting turner grass flavonoids. At the same time, the scavenging rate of DPPH free radicals and ABTS free radicals and reducing power were used as indicators to evaluate the antioxidant activity of the crude extract of damiana flavonoids. The results showed that the optimal extraction process conditions were ultrasound time 42 min, temperature 70 ℃, ultrasound power 320 W, and ethanol volume fraction 82%. Under these conditions, the extraction rate of damiana flavonoids reached 94.4%. Tests showed that the IC50 values of flavonoids of damiana in scavenging DPPH free radicals and ABTS free radicals were 0.0283 and 0.0272 mg/mL, respectively. The reducing force were stronger than VC. This optimized process is feasible, and flavonoids from damiana have good antioxidant properties.

Labeling of liver cells with CdSe/ZnS quantum dot-based fluorescence probe below freezing point

In this paper, CdSe/ZnS quantum dots (QDs) with particle size of 5.5 ~ 9.3 nm were synthesized, and the fluorescence emission ranged from 545 ~ 616 nm. When the volume fraction of ethanol was 30%, the water-soluble QD dispersion system remained liquid under −20 °C freezing conditions, the fluorescence intensity increased with a decrease in temperature, and the quantum yield reached 79% at −20 °C. The endothelial cell adhesion molecule CD31 antibody (anti-CD31) was used as the primary antibody, QDs were coupled with IgG as the secondary antibody (QD-Ab), and effective labeling of hepatic sinusoid endothelial cells was achieved at −20 °C. Fluorescence imaging and flow cytometry analysis showed that the labeling efficiency was as high as 97%, indicating that QDs have an important application prospect in microscopic section tomography of the liver.

Purification Technology of Polysaccharides from Lophatherum gracile Brongn. by Macroporous Resin Adsorption and Its Effect on Athletic Endurance of Mice

The purified technological parameters of polysaccharide extract from Lophatherum gracile Brongn was optimized, and its effect on athletic endurance was observed. The best type of macroporous resin was selected through performance comparison of static adsorption and elution experiments, then the effects of sample solution pH, sample concentration, loading speed, sample volume, volume fraction of eluent, dosage of eluent and flow rate of elution on the dynamic purification effect were analyzed. Meanwhile, purified product on the influence of athletic endurance of mice was investigated by loading swimming test and related biochemical index detection. The results showed that the optimum purification process parameters were as follows: The initial concentration of sample solution was 5 mg/mL, the sample volume was 60 mL with loading speed of 2.0 mL/min, the pH value of sample solution was 5.0, and the volume fraction of ethanol was 80%, the eluent volume was 160 mL with flow rate of 1.0 mL/min. The purity of polysaccharide in product increased from 16.39% to 57.35%. Compared with the blank control group, the purified product groups at middle and high doses significantly prolonged exhaustive swimming time (P<0.05, P<0.01), enhanced activity of lactic dehydrogenase(P<0.05, P<0.01), decreased lactic acid and urea nitrogen content (P<0.05, P<0.01) after exercise. Therefore, polysaccharide of Lophatherum gracile Brongn. could preferably improve athletic endurance in body.

Formation of Giant Lipid Vesicles in the Presence of Nonelectrolytes—Glucose, Sucrose, Sorbitol and Ethanol

Lipid vesicles, especially giant lipid vesicles (GLVs), are usually adopted as cell membrane models and their preparation has been widely studied. However, the effects of some nonelectrolytes on GLV formation have not been specifically studied so far. In this paper, the effects of the nonelectrolytes, including sucrose, glucose, sorbitol and ethanol, and their coexistence with sodium chloride, on the lipid hydration and GLV formation were investigated. With the hydration method, it was found that the sucrose, glucose and sorbitol showed almost the same effect. Their presence in the medium enhanced the hydrodynamic force on the lipid membranes, promoting the GLV formation. GLV formation was also promoted by the presence of ethanol with ethanol volume fraction in the range of 0 to 20 percent, but higher ethanol content resulted in failure of GLV formation. However, the participation of sodium chloride in sugar solution and ethanol solution stabilized the lipid membranes, suppressing the GLV formation. In addition, the ethanol and the sodium chloride showed the completely opposite effects on lipid hydration. These results could provide some suggestions for the efficient preparation of GLVs.

Lubricity of Ethanol-Diesel Fuel Blends-Study with the Four-Ball Machine Method.

Due to the increasing consumption of fuels in heavy industries, especially in road transportation, significant efforts are being made to increase the market participation of renewable fuels, including ethanol. In diesel engines, however, ethanol cannot be used as a pure fuel, primarily due to its very low cetane number and lubricity. For this reason, greater attention is being paid to blended fuels containing diesel and varying percentages of ethanol. Tests of lubricating properties carried out in accordance with the standard HFRR (high frequency reciprocating rig) method for ethanol–diesel fuel blends have long durations, which leads to ethanol evaporation and changes in the composition of the tested fuel sample under elevated temperatures. Therefore, this study presents an alternative lubricity assessment criterion based on the measurement of the scuffing load with a four-ball machine. Lubricity tests of blends of typical diesel fuel and ethanol, with ethanol volume fractions up to 14% (v/v), were conducted using a four-ball machine with a continuous increase of the load force of the friction node. In this method the lubrication criterion was the scuffing load of the tribosystem. The obtained results provided insights into the influence of the addition of ethanol to diesel fuel on lubricating properties, while limiting the ethanol evaporation process. The results also showed that an increase in the fraction of ethanol up to 14% (v/v) in diesel fuel resulted in a decrease in the scuffing load and a corresponding deterioration in the lubricating properties of the diesel–ethanol blend. For an ethanol volume fraction of 6–14%, the changes in the scuffing load were smaller than in ethanol volume fractions of 0–6%.

Fluorescence Characteristics of CdTe Quantum Dot Colloids below the Freezing Point

In this paper, water-soluble CdTe quantum dots (QDs) with different sizes from 3 to 3.9 nm are synthesized by the aqueous phase method using glutathione as the stabilizer, and their fluorescence properties below the freezing point are studied. The results show that the QD dispersion system still maintains the liquid state at −30 °C when the volume fraction of ethanol is 30%, and its fluorescence has a strong temperature dependence below the freezing point; as the temperature decreases from 0 to −30 °C, the fluorescence intensity increases about 62–82%, and the fluorescence emission peak also blue-shifts (5–10 nm). After cycles of heating (0 °C)–cooling (−30 °C), the fluorescence intensity can still be recovered, indicating a strong fluorescence reversibility. This work provides help for expanding the application of QDs in the fields of biomedicine.

Extraction and purification of total flavonoids from Eupatorium lindleyanum DC. and evaluation of their antioxidant and enzyme inhibitory activities.

The health benefits and promising medical treatment potential of total flavonoids from Eupatorium lindleyanum DC. (TFELDC) have been recognized. The process parameters of extracting total flavonoids from Eupatorium lindleyanum DC. by ultrasonic–microwave synergistic extraction (UMSE) were optimized, and they were purified by AB‐8 macroporous resin in the current study. In addition, the antioxidant and enzyme inhibitory activities of the purified TFELDC (PTFELDC) were evaluated. The results showed that the optimal parameters of UMSE were as follows: ethanol volume fraction 71.5%, L/S ratio 12.2 ml/g, microwave power 318 W, and extraction time 143 s. After TFELDC were purified by AB‐8 macroporous resin, the total flavonoid contents of PTFELDC increased from 208.18 ± 1.60 to 511.19 ± 3.21 mg RE/g FDS. Compared with TFELDC, the content of total flavonoids in PTFELDC was increased by 2.46 times. The antioxidant activities of PTFELDC were assessed using DPPH radical, superoxide anion radical, reducing power, and ferric reducing antioxidant power assays, and the IC50 values were found to be 37.13, 19.62, 81.22, and 24.72 μg/ml, respectively. The enzyme inhibitory activities of PTFELDC were measured using lipase, α‐amylase, α‐glucosidase, and acetylcholinesterase assays with the IC50 values 1.38, 2.08, 1.63, and 0.58 mg/ml, respectively. By comparing with their positive controls, it was found that PTFELDC had good antioxidant activities, and lipase, α‐amylase, and α‐glucosidase inhibitory activities, However, the acetylcholinesterase inhibitory activity was relatively weaker. These results suggested that PTFELDC have a promising potential as natural antioxidant, antilipidemic, and hypoglycemic drugs used in functional foods or pharmaceuticals.