Ethanol Volume Fraction Research Articles

Toward nanosuspension preparation by modeling the solubility of levofloxacin and ofloxacin in ethanol + water solvent mixtures at different temperatures

The present study was conducted to assess the solubility of levofloxacin and ofloxacin in different mono- and mixed solvent systems at different temperatures to provide an experimental basis for the preparation of levofloxacin and ofloxacin nanosuspensions. To this end, the solubility of both compounds was evaluated using a solid–liquid equilibrium technique in DMSO, acetone, ethanol, NMP, and water monosolvents and ethanol–water mixed solvents at different volume fractions and temperatures. The modified versions of the van’t Hoff and Gibbs equations were recruited to calculate the thermodynamic properties of the solutions. The correlation between the solubility data of levofloxacin and ofloxacin and different mathematical models, including the Yalkowsky, Jouyban-Acree, and van’t Hoff models and their combinations was studied. According to the results, the highest and lowest solubility of levofloxacin and ofloxacin were attainable in 1 (pure ethanol monosolvent) and 0.1 v/v of ethanol fractions in ethanol/water mixed solvent. Moreover, the solubility of both compounds was superior at higher temperatures. Afterwards, the nanosuspensions were prepared using the solvent-antisolvent method. Different characterization techniques revealed the formation of the smallest particles with relatively irregular morphology in the 0.1 v/v volume fraction of ethanol in water. The XRD analysis exhibited the typical crystalline diffractions of levofloxacin and ofloxacin and the thermal transitions and stability of both compounds were investigated using DSC and TGA techniques. The results obtained in this study could be used to enhance the solubility and bioavailability of levofloxacin and ofloxacin during the drug formulation development and manufacturing processes.

Surface, micellization, and thermodynamic behavior of cetyltrimethylammonium bromide in sodium polystyrene sulfonate with and without methyl red in water–ethanol mixed solvent media at varying temperatures: A tensiometric analysis

In this study, we aim to systematically investigate the surface, micellization, and thermodynamic properties of Cetyl Trimethyl Ammonium Bromide (CTAB) in Sodium Polystyrene Sulfonate (NaPSS) solutions with and without methyl red (MR) dye in water–ethanol mixed solvent media (0, 0.1, 0.2, and 0.3 vol fraction of ethanol at 298.15 ± 0.2 K, 308.15 ± 0.2 K, and 318.15 ± 0.2 K. By employing surface tension measurements, we seek to uncover the effects of solvent composition, temperature, polyelectrolyte presence, and dye addition on the Critical Micelle Concentration (CMC) and other key surface and thermodynamic parameters. The CMC, slope (dγdlnC), and γCMC values determined from γ versus ln [CTAB] for the CTAB + NaPSS + MR diminish in contrast to the CTAB + NaPSS in the chosen solvent and the temperature range studied. However, with a rising temperature and ethanol volume fraction, the CMC value rises while the obtained γCMC values fall. Various surface and thermodynamic parameters like γCMC,Amin,Γmax, ΠCMC, adsorption efficiency (PC20), packing parameter (P), aggregation number (Nagg), micellization Gibbs’ energy (ΔGm0), adsorption of Gibbs’ energy (ΔGads0), effective Gibbs’ energy (ΔGeff0), minimum Gibbs’ energy (ΔGmin), and many other parameters have been determined, comparatively discussed, and analyzed for CTAB + NaPSS and CTAB + NaPSS + MR systems. This research provides a deeper understanding of the fundamental behaviors of these complex systems, their stability, and their feasibility, with potential implications for their practical applications in fields such as drug delivery, wastewater treatment, and the formulation of personal care products.

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.

Ultrasonic-Assisted Biphasic Aqueous Extraction of Polyphenols from Vaccinium Dunalianum Leaves: Optimization, Antioxidant, and Tyrosinase Inhibition Activities.

To optimize the ultrasonic-assisted biphasic aqueous extraction conditions for polyphenolic compounds from Vaccinium dunalianum Wight leaves and investigate their antioxidant and tyrosinase inhibition activities, single-factor experiments were conducted to investigate the effects of ethanol volume fraction (%), ammonium sulfate mass fraction (%), solid-liquid ratio (g/mL), ultrasonic temperature (°C), and ultrasonic time (min) on polyphenolic content during extraction. Based on these experiments, three key factors influencing extraction were selected for response surface methodology (RSM) optimization. The results indicated that under conditions of 26 % ethanol, 20 % ammonium sulfate, a solid-liquid ratio of 1 : 30, and extraction for 35 minutes at 50 °C, the polyphenol content reached 61.62 mg/g. The relative contents of 6'-O-caffeoylarbutin, β-arbutin, and chlorogenic acid were 34.45 %, 4.56 %, and 31.06 %, respectively. The DPPH⋅ and ABTS+⋅ scavenging rates were above 95 % and 96 %, respectively, and the ferric reducing ability exhibited a significant dose-effect relationship. The inhibition rates of monophenolase and diphenolase activities of tyrosinase were 43.84 % and 35.73 %, respectively. The optimized process for ultrasonic-assisted biphasic aqueous extraction of polyphenols from Vaccinium dunalianum Wight leaves demonstrated significant antioxidant and tyrosinase inhibition activities.

Enrichment of secoiridoid glycosides from Gentiana rigescens extracts in amino acid-based deep eutectic solvents via macroporous resin adsorption

The simultaneous enrichment of the secoiridoid glycosides gentiopicroside, loganic acid, swertiamaroside, and sweroside from amino acid-based deep eutectic solvent (AADES) extracts of Gentiana rigescens roots and rhizomes was developed. To screen suitable resins, the performance and characterization of 11 widely used macroporous resins for the adsorption and desorption of target secoiridoid glycosides were considered. Compared with the other resins, the H103 resin was found to have greater adsorption and desorption capacities for gentiopicroside, loganic acid, swertiamaroside, and sweroside. Therefore, this resin was chosen as the best resin for secoiridoid glycosides enrichment. In a column packed with H103 resin, the dynamic adsorption and desorption factors for the target secoiridoid glycosides were investigated and optimized. After dynamic testing on the H103 packed column, the optimal operating conditions were determined as follows: a sample volume of 12 bed volumes (BVs) and a loading flow rate of 2 BV/h were used, the volume of deionized water used for the aqueous washing process was 8 BV, and the aqueous washing flow rate was 3 BV/h. Ethanol with a volume fraction of 10–90 % was used as the eluent in the ethanol desorption process with a gradient of 10 %. Each ethanol volume fraction was used for 2 BV, with a flow rate of 3 BV/h. The eluent fractions containing 40–80 % ethanol were collected, combined, and concentrated, followed by vacuum drying to obtain the final product. The purities of gentiopicroside, loganic acid, swertiamaroside, and sweroside in the final product were 58.11, 13.73, 3.86, and 2.77 %, respectively, with corresponding recovery rates of 74.09, 72.19, 77.50, and 76.45 %, respectively. Additionally, the reuse of AADES proved to be effective.

Study on the Kinetic Model of Mixed Fermentation by Adding Glutathione-Enriched Inactive Dry Yeast

In order to investigate the impact of glutathione-enriched inactive dry yeast (g-IDY) on the co-fermentation process of Torulaspora delbrueckii and Saccharomyces cerevisiae, different contents of g-IDY (0, 20, 40, and 100 mg/L) were added to the simulated liquid for fermentation. The yeast quantity, reducing sugar content, and ethanol volume fraction in the fermentation system were determined every 24 h. Nonlinear fitting of the measured values was carried out using classical Logistic, SGompertz, Boltzmann, and DoseResp models. Additionally, the aroma components of the wine were analyzed by GC-MS. The results indicate that the Logistic model performs best in terms of yeast growth kinetics, whereas the DoseResp and Boltzmann models exhibit the same fitting performance for reducing sugar consumption, both superior to the Logistic model, and the Boltzmann model shows the best-fitting performance for ethanol production. All optimal models have fitting coefficients (R2 values) above 0.99, demonstrating that different contents of g-IDY can effectively complete fermentation. Furthermore, all three fitting models can effectively describe the fermentation process using g-IDY. The use of g-IDY can increase the content of ethyl phenylacetate and phenylethanol, which can be employed to enhance the aroma of wine.

Interaction between methyl red and cetyltrimethylammonium bromide under the influence of sodium polystyrene sulphonate in ethanol-water binary solvent systems: A spectrophotometric investigation

This research aims to comprehensively investigate and analyze the UV–visible spectroscopic behavior of the methyl red (MR)-cetyltrimethylammonium bromide (CTAB) system under the influence of sodium polystyrene sulfonate (NaPSS) in aqueous and different volume fractions (v.f.) of ethanol (EtOH)–H2O (0.1, 0.2, and 0.3) at 298.15 ± 0.2 K. In EtOH–H2O solvent systems, the triple interactions of dyes-surfactants-polyelectrolyte (DSP) complex systems are entirely novel. MR interacts with CTAB in NaPSS in the binary solvent media (0.1, 0.2, and 0.3 v.f. of EtOH–H2O) resulting in the formation of ion-pairs at very low CTAB concentrations, far below their apparent critical micelle concentration (CMC*) reducing the absorbance, and the new complexes above the CMC* due to solubilization of the MR into CTAB micelles observed by distinct spectral shifts. The CMC* values obtained from spectroscopic data increase in the order: (CMC*)water< (CMC*)0.1< (CMC*)0.2< (CMC*)0.3. This is because of the reduced polarity or dielectric constant and increased degree of water structure disruption around the hydrophobic chains of CTAB, where micelle formation occurs at somewhat higher concentrations. The Gibbs energy of micellization (ΔGmo) increases in the order: (ΔGmo=−16.89)water <(ΔGmo=−16.17)0.1<(ΔGmo=−15.62)0.2<(ΔGmo=−15.38)0.3, which further supports the inhibitory effect of increasing ethanol content towards micellization. In the post-micellar region, the decrease in hydrophobic interactions and an increase in electrostatic interactions lead to a rise in the overall binding constant value. This means that, when NaPSS is present, the stronger electrostatic interactions in the post-micellar region contribute significantly to the increased binding of CTAB micelles with MR. The tautomeric activity of MR and the solvent composition played a prime role in affecting the interaction mechanism, as evidenced by the blue and red spectral shifts.

Optimization of Flavonoid Extraction from Abelmoschus manihot Flowers Using Ultrasonic Techniques: Predictive Modeling through Response Surface Methodology and Deep Neural Network and Biological Activity Assessment.

Understanding the optimal extraction methods for flavonoids from Abelmoschus manihot flowers (AMF) is crucial for unlocking their potential benefits. This study aimed to optimize the efficiency of flavonoid extraction from AMF. After comparing extraction methods, the ultrasonic cell crusher demonstrated superior performance over conventional techniques. Four key factors-solid-to-liquid ratio (1:10 to 1:50 g·mL-1), ethanol concentration (55% to 95%), ultrasonic time (10 to 50 min), and ultrasonic power (5% to 25% of 900 W)-were investigated and normalized using the entropy weight method. This led to a comprehensive evaluation (CE). Optimization of extraction conditions for the ultrasonic cell crusher was achieved through response surface methodology and a deep neural network model, resulting in optimal parameters: ethanol volume fraction of 66%, solid-to-liquid ratio of 1:21 g/mL, extraction efficiency of 9%, and extraction duration of 35 min, yielding a CE value of 23.14 (RSD < 1%). Additionally, the inhibitory effects of the optimized extracts against Streptococcus mutans (S. mutans) were assessed. The results revealed that AMF extract (AMFE) exhibits inhibitory effects on S. mutans, with concomitant inhibition of sucrase and lactate dehydrogenase (LDH). The MIC of AMFE against planktonic S. mutans is 3 mg/mL, with an MBC of 6 mg/mL. Within the concentration range of 1/8 MIC to 2 MIC of AMFE, the activities of sucrase and LDH decreased by 318.934 U/mg prot and 61.844 U/mg prot, respectively. The antioxidant activity of AMFE was assessed using the potassium ferricyanide reduction and phosphomolybdenum methods. Additionally, the effect of AMFE on DPPH, ABTS, and ·OH free radical scavenging abilities was determined. The concentrations at which AMFE exhibited over 90% scavenging rate for ABTS and DPPH free radicals were found to be 0.125 mg/mL and 2 mg/mL, respectively.

Extraction, Purification, and in vitro Antioxidant Activity Assessment of Total Flavonoids from the Aerial Parts of Tetrastigma hemsleyanum

Background The effective extractives of Tetrastigma hemsleyanum ( T. hemsleyanum) are useful, but this plant was not fully utilized in rural China. In this study, flavonoids from the aerial parts of T. hemsleyanum were extracted, and the purification method and the antioxidant capability were explored. Purpose This study is to explore the optimized purification method and the biological capability of the total flavonoids extracted from T. hemsleyanum. Materials and Methods The optimal extraction conditions were determined by single-factor and Box-Behnken design experiments. The antioxidant activities were assessed by analyzing their capability to scavenge 2,2-diphenyl-1-picrylhydrazyl and OH free radicals. Results and Discussion The optimal conditions for the extraction of the total flavonoids were as follows: ethanol volume fraction 60%, liquid-to-material ratios 35:1 mL/g, temperature 45℃, and time 85 min. The extraction rate of the total flavonoids was (3.59 ± 0.03)%. NKA-9 is an ideal macroporous resin for purification. The optimized purification process conditions of flavonoids were mass concentration of adsorption solution 1.50 mg/mL, pH value of adsorption solution 4.0, sample loading flow rate 2 BV/h, ethanol volume fraction in desorption process 60%, desorption flow rate 2 BV/h and elution volume 4 BV. After crude extracts were purified by NKA-9 macroporous resin, the content of the total flavonoids enhanced from (21.76 ± 0.18)% to (58.92 ± 0.22)%. The results of the experiments for antioxidant activity showed that the half maximal inhibitory concentration (IC50) values of the purified flavonoids extracted were 33.1and 42.7 µg/mL, respectively. Conclusion The results of this study indicated that the flavonoids in T. hemsleyanum have good antioxidant activity in vitro and deserve exploring in further pharmacological studies.

Study on the total flavonoid content and antioxidant activity of Morus nigra Linn. from different origins in Xinjiang

Optimization of the extraction process of total flavonoids from Morus nigra Linn. based on response surface design, to compare the differences in total flavonoid content of Morus nigra Linn. from different origins in Xinjiang and its relationship with antioxidant activity. A one-way test was used to investigate the effects of ethanol volume fraction, material-liquid ratio, ultrasonic power and ultrasonic time on total flavonoid content analysis of Morus nigra Linn. , Box-Behnken response surface design optimisation was used to derive the optimal extraction process parameters. Meanwhile, the in vitro antioxidant activity of Morus nigra Linn. was evaluated by antioxidant activity indexes such as hydroxyl radical scavenging capacity and ferric ion reducing capacity. The optimal extraction condition was 45% ethanol by volume, 1∶20 g/mL material-liquid ratio, 300W ultrasound power and 60 min ultrasound time. The total flavonoid content of Morus nigra Linn. s from six origins was detected and the result showed that Kuche &gt;Kashgar &gt;Kuche Wuqia Town&gt;Hetian &gt;Ying jisha &gt;Yutian, in which the total flavonoid content of mulberry in Kucha city was(27.159±0.091)mg/g. The difference in the total flavonoid content of Morus nigra Linn. s in different origicns was statistically significant(P&lt;0.05). In vitro antioxidant activity analysis showed that the antioxidant activity of mulberry from Kuche and Hetian was stronger, and the hydroxyl radical scavenging capacity, ferric ion reducing capacity, and total antioxidant capacity of mulberry from various origins were statistically significant(P&lt;0.05). The correlation analysis showed that the total flavonoid content of Morus nigra Linn. was correlated with the antioxidant capacity to improve the scavenging of hydroxyl radicals. The ultrasonic-assisted method of extracting total flavonoids from Morus nigra Linn. is simple, and the model constructed has a high degree of fit, which can better compare the total flavonoids content of Morus nigra Linn. from different origins in Xinjiang.

Controlling Solvent Polarity to Regulate Protein Self-Assembly Morphology and Its Universal Insight for Fibrillation Mechanism.

The mechanism of ethanol-induced fibrillation of β-lactoglobulin (β-lg) in the acidic aqueous solution upon heating was investigated using various techniques, mainly thioflavin T fluorescence, atomic force microscopy, nonreducing electrophoresis, mass spectrometry, Fourier transform infrared spectroscopy, and circular dichroism spectroscopy. The results showed that fibrillation occurred with a heating time increase, but high ethanol content slowed down the process. At a low ethanol volume fraction, peptides existed after heating for 2 h, with long and straight fibrils formed after 4-6 h, while at a high ethanol volume fraction, the proteins aggregated with very few peptides appeared at the early stage of heating, and short and curved fibrils formed after heating for 8 h. Ethanol weakened the hydrophobic interactions between proteins in the aqueous solution; therefore the latter could not completely balance the electrostatic repulsion, and thus suppressing the fibrillation process. It is believed that the fibrillation of β-lg in the acidic solution upon heating is mainly dominated by the polypeptide model; however, ethanol inhibited the hydrolysis of proteins, and the self-assembly mechanism changed to the monomer model.

Investigation on screening, identification, and fermentation characteristics of Yunnan olive in the fermented liquid utilizing five strains of Saccharomyces cerevisiae.

Refined indigenous Saccharomyces cerevisiae can enhance refinement, sophistication, and subtlety of fruit wines by showcasing exceptional regional characteristics. In order to identify exceptional indigenous S. cerevisiae strains from Yunnan olive, this study isolated 60 yeast strains from wild Yunnan olive fermentation mash. The five S. cerevisiae strains were subjected to morphological and molecular biological identification, followed by evaluation of their fermentation performance, ethanol production capacity, ester production capacity, H2S production capacity, killing capacity, and tolerance. Strains LJM-4, LJM-10, and LJM-26 exhibited robust tolerance to 6% ethanol volume fraction, pH 2.8, sucrose concentration of 400g/L, SO2 concentration of 0.3g/L, glucose concentration of 400g/L at both 40°C and 15°C. Additionally, strain LJM-10 demonstrated a faster fermentation rate compared to the other strains. Among the tested S. cerevisiae strains evaluated in this study for olive wine fermentation process in Yunnan region; strain LJM-10 displayed superior abilities in terms of ester and ethanol production while exhibiting the lowest H2S production levels. These findings suggest that strain LJM-10 holds great potential as an excellent candidate for optimizing fruit wine S. cerevisiae fermentation processes in Yunnan olive fruit wine.

Optoacoustic interferometric characterization system (OPTICS) for the evaluation of fuel quality through speed of sound measurements

Ultrasonic techniques have been applied to assess crucial physical parameters in various types of fuels including the speed of sound (SoS), the bulk modulus and the acoustic attenuation coefficient. Such investigations may have important practical significance as the knowledge of fuel properties is directly related to the analysis of combustion characteristics, engine’s overall performance and exhaust emission in the environment. Nevertheless, typical pulse-echo acoustic methods, require the exact determination of both acoustic source – reflector distance and the time of flight of a finite temporal width ultrasonic pulse, setting thus an upper limit as regards the accuracy of the measurements. To encounter these challenges, we present a novel technology implemented through a low-cost and potentially portable optoacoustic interferometric characterization system (OPTICS) for the investigation of SoS variations in common fuels including automotive diesel, hydrous ethanol and gasoline. At 25 °C, diesel/kerosene blends demonstrated a SoS variation ranging from 1322.91 m/s (0.6 diesel volume fraction) to 1349.79 m/s (diesel fuel only), whereas hydrous ethanol samples varied between 1199.92 m/s (0.95 ethanol volume fraction) to 1149.39 m/s (pure ethanol only). Finally, assessments for 95 and 100 research octane number (RON) gasoline blends showed a SoS range from 1134.42 m/s (RON 95) to 1159.86 m/s (RON 100). The high precision and repeatability (relative uncertainty: ∼10-4) of the performed SoS measurements in controlled samples, has demonstrated the promising potential of OPTICS for the evaluation of fuel physical properties as well as the potential detection of contamination with adulterants.

Extraction and Purification of Nicotine from Tobacco Rhizomes by Supercritical CO2.

Currently, in the ongoing development of the tobacco industry, a large amount of tobacco rhizomes is discarded as waste. These wastes are usually disposed of through incineration or burial. However, these tobacco wastes still have some economic value. High-purity nicotine has a promising market outlook as the primary raw material for electronic cigarette liquid. Nicotine is not only found in tobacco leaves but also in the rhizomes of tobacco plants. This study presents a method for treating tobacco waste and extracting high-purity nicotine from it. After mixing the raw material powder and entrainer in specific ratios, as much of the nicotine in tobacco roots can be extracted as possible using supercritical carbon dioxide extraction. The effects of temperature, the ratio of the entrainer, and the volume fraction of ethanol in the entrainer on the nicotine yield in supercritical fluid extraction (SFE) at 25 MPa for 120 min were discussed. By using 90% ethanol (a raw material mass-to-volume ratio of 1:5) as the entrainer, we obtained the highest nicotine yield of 0.49% at 65 °C. Meanwhile, the purity of the crude extract was 61.71%, and after purification, it increased to 97.57%. In this way, we can not only obtain nicotine with market value but also further reduce the harm to the environment caused by tobacco waste disposal.

Optimization of ethanol precipitation process of Nauclea officinalis extract based on concept of quality by design(QbD)

The ethanol precipitation process of Nauclea officinalis extract was optimized based on the concept of quality by design(QbD). Single factor tests were carried out to determine the levels of test factors. The ethanol volume fraction, pre-ethanol precipitation drug concentration, and ethanol precipitation time were taken as critical process parameters(CPPs). With the comprehensive scores of strictosamide transfer rate and solid removal rate as the critical quality attributes(CQAs), Box-Behnken design was employed to establish the mathematical models and space design between CPPs and CQAs, and the obtained optimal operating space was validated. The optimal operating space included ethanol volume fraction of 65%-70%, pre-ethanol precipitation drug concentration of 22-27 mg·mL~(-1), and ethanol precipitation time of 12 h. Based on the concept of QbD, this study adopted the design space to optimize the ethanol precipitation process of N. officinalis extract, which provided a reliable theoretical basis for the quality control in the production process of N. officinalis preparations. Moroever, this study provided a reference value for guiding the research and industrial production of traditional Chinese medicines.

Pinobanksin from peony seed husk: A flavonoid with the potential to inhibit the proliferation of SH-SY5Y.

Pinobanksin, as one of the flavonoids, has powerful biological activities but has been under-recognized. In this study, we optimized the extraction method of phragmites from peony seed shells by using organic solvent extraction. The yield of PSMS was 10.54 ± 0.13% under the conditions of ethanol volume fraction 70%, extraction temperature 70°C, material-liquid ratio 1:25 g/mL, and extraction time 60 min; the optimized PSMS could be effectively separated in S-8 macroporous resin coupled with C18. The relative content of PSMS was increased from 0.42% in PSMS to 92.53% after C18 purification; the antioxidant activity test revealed that pinobanksin could exert antioxidant ability by binding catalase (CAT) enzyme. Second, it was found that pinobanksin could effectively inhibit the proliferation of SH-SY5Y cells, mainly by binding to BCL2-associated X (BAX), B-cell lymphoma-2 (BCL-2), and cyclin-dependent Kinase 4/6 (CDK4/6) to produce more hydrogen bonds to inhibit their activities. This study confirms the medicinal potential of pinobanksin and provides the basis for the proper understanding of pinobanksin and the development of related products.

Establishment and Optimization of Flavonoid Extraction and Detection System for Hemerocallis

Hemerocallis is a characteristic vegetable with outstanding edible and medicinal value. Flavonoids are important bioactive components of Hemerocallis. To improve the extraction efficiency and detection accuracy of flavonoids from Hemerocallis, we established a high-performance liquid chromatography (HPLC) detection system, which can simultaneously detect multiple flavonoids. In addition to the previously developed organic solvent extraction method, an ultrasonic-assisted extraction technique that uses fewer samples was established to extract flavonoids from Hemerocallis. The extraction conditions of the ultrasonic-assisted extraction were optimized via a single-factor experiment and a response surface experiment. The HPLC system detected and determined the contents of rutin, isoquercetin, myricetin, quercetin, apigenin, and diosmetin from 70 Hemerocallis germplasm resources. In addition, we evaluated the antioxidant activity of flavonoids in Hemerocallis using DPPH free radical scavenging capacity with ascorbic acid (Vc) as a positive control. The results showed that the optimum conditions for the ultrasonic extraction process were as follows: sample weight of 0.25 g, ethanol volume fraction of 72%, ethanol volume of 2.5 mL, and ultrasonic extraction time of 17 min. Under these conditions, flavonoid extraction had a strong scavenging effect on DPPH. With the increase in the sample solutions’ concentrations, its antioxidant capacity was gradually enhanced, and the DPPH scavenging rate reached 70.2%. The optimized ultrasonic-assisted extraction technology can increase the total content of six flavonoids in day lily bud by 59.01%, especially the content of rutin (increased by 64.41%) in Hemerocallis flower buds. Among 70 Hemerocallis plant resources, we selected materials H0087 and H0059 with high and stable flavonoid content, with the total content of six substances being 4390.54 ug/g and 3777.13 ug/g. Thus, this study provides a reference for extracting and determining flavonoid contents in Hemerocallis materials. It also provides a theoretical basis for high-quality individual plant breeding.

Study on Purification, Identification and Antioxidant of Flavonoids Extracted from Perilla leaves

The flavonoids from Perilla leaves were extracted using flash extraction assisted by ultrasonic extraction with ethanol. Subsequently, macroporous resin was employed for the isolation and purification of these flavonoids, followed by an investigation into their antioxidant activity. The process conditions for the extraction of flavonoids from Perilla leaves were designed and optimized using a one-way experiment combined with a response surface methodology. The optimal extraction conditions were determined as follows: the liquid–solid ratio was 20:1, ethanol volume fraction of 60%, ultrasound temperature of 60 °C, ultrasound time of 10 min and flash evaporation time of 60 s. The optimal extraction rate of flavonoids is 9.8 mg/g. In terms of separation and purification, a high-performance macroporous resin (HPD450 resin) with high purification efficiency was selected through static analysis and adsorption experiments. The optimal enrichment conditions were as follows: loading concentration of 0.06 mg/mL, optimal loading concentration of 20 mL, elution concentration of 70% and 76 mL, providing a reference for the further development and utilization of Perilla leaf flavonoids.

Study on Extraction and Purification of Acanthopanax senticosus Polyphenols by an Ionic Liquid-Assisted Aqueous Two-Phase System.

This study aimed to extract and purify polyphenols from Acanthopanax senticosus. A new green method was developed, in which ionic liquids (ILs) were used as aqueous two-phase (ATP) adjuvants to extract the polyphenols from A. senticosus. An ionic liquid-assisted aqueous two-phase system (IL-ATPS) was established. The purification of the polyphenols from the extraction fluid by AB-8 macroporous resin was conducted, and the kinetic mechanisms were studied. The reuse of ionic liquids was executed. The results showed that an [OMIM]Br-assisted ethanol/NaH2PO4 system (IL-ATPS) was the best extraction solvent. In this study, the following optimal extraction conditions were determined: 32 wt.% ethanol, 25 wt.% NaH2PO4, 9 wt.% additional ionic liquid, a solid-liquid ratio of 1:40 g/mL, an extraction temperature of 50 °C, a pH of 4.0, an extraction time of 50 min, and an extraction rate of the polyphenols at 15.90 mg/g. The optimum adsorption parameters of the macroporous resin AB-8 were as follows: a flow rate of 3.5 BV·h-1, a sample volume of 40 mL, an elution flow rate of 3.5 BV·h-1, an eluent volume of 80 mL, and an eluant that was constituted by an 85% volume fraction of ethanol. The decolorization effect of 4% activated carbon was better than the other amounts; in addition, a decolorization rate of 76.81% and an ionic liquid recovery rate of 81.12% were found to be the most optimal. Compared with the traditional extraction methods, IL-ATPS has the advantages of requiring simple operation, saving time, and high efficiency. In addition, it can be used for the extraction of the polyphenolic compounds.

All-round inhibition of soot generation during diesel combustion by oxygenated biomass fuels: A numerical simulation and experimental study

Soot generated from diesel combustion is an important pollutant source in the atmosphere. Meanwhile, oxygenated biomass fuels are potential green alternatives to diesel that suppress soot formation. The purpose of this study is to evaluate the effect of oxygenated biomass fuels (biodiesel and ethanol) on all soot precursors (polycyclic aromatic hydrocarbons (PAHs)) and soot particles during diesel combustion. Kinetic modeling results showed that both biodiesel and ethanol monotonically reduced the concentration of PAHs mainly by inhibiting their production and facilitating their oxidation. Specifically, the C2-C4 content reduced and the O, H, and OH concentrations increased. Ethanol has a more profound inhibitory effect on pyrene than biodiesel, mainly due to the reduction of C2-C4 species and increased production of CO2 and CO. Soot particles generated from the combustion of diesel (D100) and its blends (D0.8B0.2/B0.1D0.8E0.1/D0.8E0.2; D and E represent the volume fractions of biodiesel and ethanol in diesel, respectively) were collected on an in-house premix burner. Soot particles were further characterized using thermogravimetric analysis (TGA), elemental analysis (EA), fourier infrared spectroscopy (FTIR), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM). The activation energy of D100 was found to be significantly higher than that of other soot particle samples. After blending oxygenated biomass fuels, there is an increase in O elements, oxygen-containing functional groups, layer spacing and streak distance inside PAH crystals, and streak curvature in soot particles; however, there is a decrease in C elements, aliphatic functional groups, crystal size and crystal stacking thickness of PAHs, and average stripe length. These changes indicate that oxygenated biomass fuels allow soot particles to exhibit a higher oxidation activity, which reduces the amount of soot generated by diesel combustion.