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Article
In-Line Measurement of Extraction Process by Slug Flow and Determination of Mass Transfer Parameters
Separations 2023, 10(8), 443; https://doi.org/10.3390/separations10080443 - 08 Aug 2023
Viewed by 56
Abstract
The primary objective of this study was to pragmatically implement an extraction process using slug flow, wherein two immiscible phases, aqueous and oil, are alternatively channeled through a conduit to encourage mass exchange across the interface. To facilitate this, we introduced and empirically [...] Read more.
The primary objective of this study was to pragmatically implement an extraction process using slug flow, wherein two immiscible phases, aqueous and oil, are alternatively channeled through a conduit to encourage mass exchange across the interface. To facilitate this, we introduced and empirically validated an in-line technique to precisely quantify the length of the slug and the potential extraction concentration of the two aforementioned phases. The length of the slug and its concentration were ascertained through conductivity, utilizing platinum wire as the electrode. This method consistently produced results with a maximum error margin of ±5%. Using this apparatus, we determined key mass transfer parameters, including the overall mass transfer coefficient. Notably, as the linear velocity amplified, so did the extraction rate. These findings present a significant opportunity for enhancing the efficiency of the extraction process and enabling its optimization. Full article
(This article belongs to the Topic Advances in Chemistry and Chemical Engineering)
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Article
Effects of Catha edulis (Khat) on the Pharmacokinetics of Metformin in Diabetic Rats Using UPLC/MS/MS Analysis and Its Impact on Hepatic CYP450 Enzymes
Separations 2023, 10(8), 442; https://doi.org/10.3390/separations10080442 - 08 Aug 2023
Viewed by 100
Abstract
Catha edulis Forsk., commonly known as Khat, is a stimulant plant that is chewed in the Horn of Africa and the southern regions of the Arabian Peninsula. It is often used alongside conventional drugs, but there is a lack of research on [...] Read more.
Catha edulis Forsk., commonly known as Khat, is a stimulant plant that is chewed in the Horn of Africa and the southern regions of the Arabian Peninsula. It is often used alongside conventional drugs, but there is a lack of research on its interactions with other drugs. In this study, our aim was to investigate the possibility of an herb–drug interaction between KT extract and metformin (MT) by exploring the effect of KT on the in vivo pharmacokinetics of MT in diabetic Wistar albino rats and monitoring blood glucose levels through time intervals, comparing when MT was given alone and co-administered with KT. Rats were given 500 mg/kg of KT extract and 300 mg/kg of MT daily for 7 days. The pharmacokinetic parameters of MT were analyzed using UPLC-MS/MS. The quantification was conducted using multiple reaction monitoring (MRM) in positive ion mode. The transitions used were (m/z) 130.006→59.939 for MT and 260.125→116.018 for propranolol as an internal standard (IS). An Acquity UPLC BEH HSS T3 C18 column was used with isocratic elution, and the mobile phase was formic acid (0.1%): acetonitrile (70:30 v/v) at a flow rate of 0.25 mL/min. In addition, the study delved into the in vitro impact of KT on the CYP3A4 enzyme, seeking to identify any potential disruptions in MT’s metabolism that could alter its pharmacokinetics. The effect of KT extract on CYP3A4 enzyme activity was investigated using fluorescence-based enzyme assays and a CYP3A4 Inhibitor Screening Kit. The results indicated that the combined treatment showed increased systemic exposure to MT, with Cmax and AUC levels increasing by 33.42% and 45.23%, respectively. Additionally, the combination treatment led to significantly lower fasting blood glucose (FBG) levels compared to the groups treated with MT alone. It was found that at a concentration of 500 µg/mL, the CYP3A4 enzyme activity was maximally suppressed by approximately 57%, while at 250 µg/mL, it was inhibited by almost 50%. In comparison, the standard Ketoconazole only inhibited CYP3A4 activity by approximately 58%. Therefore, the in vitro results suggest that KT extract has the potential to affect CYP3A4 activity at high doses. In conclusion, the combination treatment resulted in a significant increase in MT’s blood sugar-lowering effects. Therefore, it is important to be aware of this potential interaction and to monitor blood sugar levels closely when using KT alongside MT. Full article
(This article belongs to the Section Chromatographic Separations)
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Review
Enhanced Adsorption of Chromate and Arsenate Ions from Contaminated Water with Emphasis on Polyethylenimine Modified Materials: A Review
Separations 2023, 10(8), 441; https://doi.org/10.3390/separations10080441 - 07 Aug 2023
Viewed by 261
Abstract
Heavy metals in water pose a great threat to human health, and water treatment remains a critical issue globally. Among various water treatment techniques, adsorption has been proven to be an excellent way to remove heavy metals from water due to its advantages, [...] Read more.
Heavy metals in water pose a great threat to human health, and water treatment remains a critical issue globally. Among various water treatment techniques, adsorption has been proven to be an excellent way to remove heavy metals from water due to its advantages, like low cost, availability, profitability, ease of operation, and efficiency. Heavy metals such as chromium and arsenic are present in water in the form of anions, while many common adsorbents, such as biochar and activated carbons, cellulose, chitosan, clays, and silica, tend to acquire a negative surface charge. The surface charge of the adsorbent plays a major role in its interaction with heavy metal ions. Polyethylenimine is a polymer with a high cationic charge density. Modification of these adsorbents with polyethylenimine results in higher selectivity for these anions. The adsorption capacity is related to the efficiency of the introduction of polyethylenimine, which depends on the surface properties of the adsorbent. This review focuses on the effect of modification with polyethylenimine on the adsorption capacity of common adsorbents for the removal of heavy metal ions, such as chromate and arsenate, from water. Full article
Article
Enhancement of Photocatalytic Rhodamine B Degradation over Magnesium–Manganese Baring Extracted Iron Oxalate from Converter Slag
Separations 2023, 10(8), 440; https://doi.org/10.3390/separations10080440 - 03 Aug 2023
Viewed by 362
Abstract
In this work, iron oxalate from converter slag (FeOX-Slag) was produced by extraction of iron from converter slag using oxalic acid, followed by photo-reduction. The FeOX-Slag sample was subjected to various characterization techniques, including X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy with [...] Read more.
In this work, iron oxalate from converter slag (FeOX-Slag) was produced by extraction of iron from converter slag using oxalic acid, followed by photo-reduction. The FeOX-Slag sample was subjected to various characterization techniques, including X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL), X-ray absorption near-edge structure spectroscopy (XANES), and X-ray photoelectron spectroscopy (XPS), in order to gain insights into its physicochemical properties. Also, to compare the photocatalytic activity of the FeOX-Slag, commercial iron oxide (Fe2O3) was used as a precursor to produce normal iron oxalate (FeOX-Fe2O3). The obtained FeOX-Slag was applied to the photocatalytic degradation of rhodamine B (RhB), a model organic contaminant in wastewater, compared with the FeOX-Fe2O3. Using the produced FeOX-Slag, we were able to degrade RhB more than 98% within 90 min at a reaction rate constant of about 3.6 times faster than FeOX-Fe2O3. Photoluminescence results confirmed the less recombination of the electron–hole pairs in FeOX-Slag, compared to FeOX-Fe2O3, which may be due to the defect structure of iron oxalate by guest metal impurities. The higher separation and transportation of photogenerated electron–hole pairs cause the enhancement of the degradation photocatalytic RhB degradation activity of the FeOX-Slag. In addition, The FeOX-Slag showed higher light absorption ability than FeOX-Fe2O3, resulting in the enhancement of the RhB degradation performance. Thus, the optical properties and the results from the activity tests led to the proposal that FeOX-Slag may be used in a photocatalytic degradation process for RhB under light irradiation. Full article
(This article belongs to the Special Issue Pollutants Removal by Photocatalytic Degradation)
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Editorial
Chromatographic Separations
Separations 2023, 10(8), 439; https://doi.org/10.3390/separations10080439 - 02 Aug 2023
Viewed by 465
Abstract
The topic of chromatographic separations is a recent addition to the Separations journal [...] Full article
(This article belongs to the Section Chromatographic Separations)
Article
Removal of Pb(II) from Aqueous Solution and Adsorption Kinetics of Corn Stalk Biochar
Separations 2023, 10(8), 438; https://doi.org/10.3390/separations10080438 - 02 Aug 2023
Viewed by 370
Abstract
In this work, the Pb adsorption and removal ability of biochar from simulated Pb(II)-contaminated wastewater, adsorption isotherms, kinetics, and thermodynamics were studied. Adsorption characteristics of biochar on Pb(II) were analyzed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscope [...] Read more.
In this work, the Pb adsorption and removal ability of biochar from simulated Pb(II)-contaminated wastewater, adsorption isotherms, kinetics, and thermodynamics were studied. Adsorption characteristics of biochar on Pb(II) were analyzed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscope with energy dispersive spectrometer (SEM-EDS). The influence of the pH of the solution, the contact time, and the biochar dose on the removal of Pb(II) were investigated by single-factor design and response surface analysis. With the increase in biochar dose from 2 g/L to 4 g/L in wastewater, the Pb(II) amount adsorbed on biochar reduced from 21.3 mg/g to 17.5 mg/g. A weakly acidic environment was more conducive to the ligand exchange between Pb(II) ions and biochar. Pb(II) adsorption kinetics of biochar showed that the Pseudo-first-order model was more suitable than other employed models to describe the adsorption process. During the isothermal adsorption process, Langmuir and Freundlich’s isotherms fitted the adsorption data very well (R2 > 96%). The Pb (II) adsorption onto biochar was spontaneous in the specified temperature range (298–318 K) and the process was exothermic. Simultaneously, the optimal conditions were a pH of 5, a contact time of 255 min, and a biochar dose of 3 g/L, under which the maximum predicted Pb(II) removal efficiency was 91.52%. Full article
(This article belongs to the Special Issue Carbon-Based Materials for Contaminant Removal)
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Article
Optimization of the Preparation of Hydrophilic Poly(DHPMA-co-MBA) Monolithic Capillary Columns: A New Support for Affinity Chromatography
Separations 2023, 10(8), 437; https://doi.org/10.3390/separations10080437 - 02 Aug 2023
Viewed by 204
Abstract
In miniaturized affinity chromatography, the development of hydrophilic organic monoliths with reduced non-specific interactions and high-protein grafting capacity remains a hot topic. In this work, we propose the one-step synthesis of a diol organic monolith to replace the gold-standard epoxy-based organic monoliths (which [...] Read more.
In miniaturized affinity chromatography, the development of hydrophilic organic monoliths with reduced non-specific interactions and high-protein grafting capacity remains a hot topic. In this work, we propose the one-step synthesis of a diol organic monolith to replace the gold-standard epoxy-based organic monoliths (which require post-modification, namely hydrolysis, prior to use). The synthesis of this new monolith builds upon the use of N-N’-Methylenebis(acrylamide) (MBA), as a hydrophilic crosslinker, and 2,3-dihydroxypropyl methacrylate (DHPMA), a diol monomer that eliminates the time-consuming epoxy ring opening step and its associated side reactions. The optimization of one-step synthesis parameters led to a monolith with a satisfactory permeability ((4.8 ± 0.5) × 10−14 m2), high efficiency (117,600 plates/m at optimum flow velocity (uopt = 0.09 cm s−1)) and reduced non-specific interactions. It is exemplified by its separation ability in the HILIC mode (separation of nucleosides), and by the retention data set of 41 test solutes, which were used to evaluate the non-specific interactions. This new poly(DHPMA-co-MBA) monolith has not only hydrophilic surface properties, but also improved protein grafting capacity compared to the glycidyl-based monolith (13 ± 0.7 pmol cm−1). The potential of this monolith is illustrated in affinity chromatography, where the concanavalin ligands are ranked according to their Kd values. Full article
(This article belongs to the Section Chromatographic Separations)
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Article
Chemometric Approach of Different Extraction Conditions on Scavenging Activity of Helichrisym italicum (Roth) G. Don Extracts
Separations 2023, 10(8), 436; https://doi.org/10.3390/separations10080436 - 02 Aug 2023
Viewed by 214
Abstract
Helichrysum italicum (Roth) G. Don is widely used as a liver stimulant and diuretic, as well as an antioxidant, antiallergenic, antimicrobial, antiviral, choleric, and antihypertensive agent. Therefore, the purpose of this study was to analyze the different extracts of H. italicum and to [...] Read more.
Helichrysum italicum (Roth) G. Don is widely used as a liver stimulant and diuretic, as well as an antioxidant, antiallergenic, antimicrobial, antiviral, choleric, and antihypertensive agent. Therefore, the purpose of this study was to analyze the different extracts of H. italicum and to determine the relationship between total phenolic/flavonoid content and antioxidant activity. Plant material was pulverized to be 0.3 and 2 mm, and the extraction was obtained with 5 mL of different ethanol concentrations (30, 40, 50, 60, 96%, v/v) and water during different periods (10, 30, 60 min and 24 h) and with concentrated methanol (95%, v/v), dichloromethane, acetone, chloroform, ethyl acetate, and hexane during 10 and 30 min due to solvents volatility. Extracts were evaporated on the rotary evaporator. Total phenolic and flavonoid content were determined via spectrophotometric measurement, and antioxidant capacity was investigated by the inhibitory activity of DPPH radicals. The group of 92 extracts described through their TPC, flavonoids, yield, and IC50 values were subjected to PCA and HCA analysis. PCA and HCA were performed using Statistica v 10.0 software. The number of phenolic compounds ranged from 2.58 ± 0.1 to 43.60 ± 0.3 mg GAE/g of dry extract, and total flavonoids content ranged from 0.25 ± 0.01 to 23.96 ± 0.19 mg QE/g of dry extract. All extracts showed good antioxidant activity with an IC50 value in the range from 4.92 ± 0.2 to 231.12 ± 1.9 μg/mL. PCA and HCA analysis were performed on the whole data set comprising 92 extracts for both particle sizes (s0.3 and s2) as well as heat map analysis. It was found that the increased time of extraction, concentration of ethanol, and degree of fragmentation enhances the quality of the extracts in terms of phenolic component content and antioxidant effects. Applied chemometric analysis contributed to the extraction conditions grouping, overview, and selection in order to distinguish the extracts with the promising TPC, flavonoids, yield, and IC50 values. Full article
(This article belongs to the Special Issue Extraction and Analysis of Active Ingredients from Natural Products)
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Article
Screening and Experimental Validation for Selection of Open Metal Sites Metal-Organic Framework (M-CPO-27, M = Co, Mg, Ni and Zn) to Capture CO2
Separations 2023, 10(8), 434; https://doi.org/10.3390/separations10080434 - 01 Aug 2023
Viewed by 203
Abstract
The release of CO2 into the atmosphere has become a primary issue nowadays. Recently, researchers found Metal-Organic Frameworks M-CPO-27 (M = Mg, Co, Ni, and Zn) to be revolutionary for CO2 adsorption due to the presence of open metal sites enhancing [...] Read more.
The release of CO2 into the atmosphere has become a primary issue nowadays. Recently, researchers found Metal-Organic Frameworks M-CPO-27 (M = Mg, Co, Ni, and Zn) to be revolutionary for CO2 adsorption due to the presence of open metal sites enhancing CO2 binding and leading to higher capacity. This study aims to select the best metal center for CPO-27 with the high performance of CO2 adsorption by screening metal centers using simulation as a preliminary selection method. Then, the different metal centers were synthesized using the solvothermal process for validation. The synthesis of MOFs is confirmed through PXRD and FTIR analysis. Subsequently, by using simulation and experimental methods, it is discovered that Ni-CPO-27 gives the best performance compared with magnesium, zinc, and cobalt metal centers. The CO2 adsorption capacity of synthesized Ni-CPO-27 is 5.6 mmol/g, which is almost 20% higher than other MOFs. In conclusion, the prospective outcome of changing the metal from Mg-CPO-27 to Ni-CPO-27 would be advantageous in this investigation owing to its excellent performance in capturing CO2. Full article
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Article
Isolation of Osteoblastic Differentiation-Inducing Constituents from Peanut Sprouts and Development of Optimal Extraction Method
Separations 2023, 10(8), 435; https://doi.org/10.3390/separations10080435 - 01 Aug 2023
Viewed by 269
Abstract
Osteoporosis, one of the most common bone diseases, results from an imbalance between bone formation and resorption. Osteoblasts are primarily involved in bone formation, whereas osteoclasts are involved in bone resorption. Therefore, any substances that can increase osteoblastic differentiation would be beneficial for [...] Read more.
Osteoporosis, one of the most common bone diseases, results from an imbalance between bone formation and resorption. Osteoblasts are primarily involved in bone formation, whereas osteoclasts are involved in bone resorption. Therefore, any substances that can increase osteoblastic differentiation would be beneficial for the prevention or treatment of osteoporosis. In this study, peanut sprouts, a germinated product of peanuts, significantly enhanced osteoblastic differentiation of pre-osteoblastic MC3T3-E1 cells, as determined by the alkaline phosphatase (ALP) assay. The ethyl acetate fraction of peanut sprout extract was subjected to diverse column chromatographies using silica gel, ODS, and Sephadex LH-20 as stationary phases, and three nucleobases, namely, adenine, uracil, and thymine, and three phenolic acids, including caffeic acid, coumaric acid, and ferulic acid, were isolated as active constituents. In particular, adenine at 4 μg/mL and caffeic acid at 1 μg/mL increased ALP activity by 40 and 30%, respectively, compared with the osteoblastic differentiation medium-treated group, and these two compounds were set as marker compounds. Furthermore, extraction of peanut sprouts grown for 14–17 days with 60% ethanol was the best condition to obtain a high quantity of extract for peanut sprouts by analyzing the contents of marker compounds through HPLC. Together, these results suggest that peanut sprouts and their isolated compounds significantly enhance osteoblastic differentiation. Therefore, peanut sprouts have the potential to be developed as functional foods against osteoporosis. Full article
(This article belongs to the Special Issue Separation, Analysis and Biological Evaluation of Bioactive Compounds)
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Article
Water-Based Microwave-Assisted Extraction of Pigments from Madder Optimized by a Box–Behnken Design
Separations 2023, 10(8), 433; https://doi.org/10.3390/separations10080433 - 30 Jul 2023
Viewed by 190
Abstract
Water is one of the greenest and most accessible solvents. To harness its potential, the water-based microwave-assisted extraction (MAE) of pigments from madder was optimized by the response surface methodology (RSM) using a Box–Behnken experimental design. The extract that presented both the highest [...] Read more.
Water is one of the greenest and most accessible solvents. To harness its potential, the water-based microwave-assisted extraction (MAE) of pigments from madder was optimized by the response surface methodology (RSM) using a Box–Behnken experimental design. The extract that presented both the highest extraction yield and the most intense color was obtained after a 30-s cycle at 1000 W using 100 mg of madder for 20 mL of water. This water-based MAE was more efficient than Soxhlet extraction and proved comparable to hydroalcoholic MAE. The optimized extract was further characterized using UHPLC-HRMS/MS to identify its main compounds. Glycosylated flavonoids and anthraquinones were putatively identified, as well as free anthraquinones, generally found in madder. The microwave-assisted extraction extended the range of polarity of the extracted compounds, making the water more versatile. Full article
(This article belongs to the Special Issue Separation, Extraction and Purification of Natural Products)
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Article
Study of Estimated Ultimate Recovery Prediction and Multi-Stage Supercharging Technology for Shale Gas Wells
Separations 2023, 10(8), 432; https://doi.org/10.3390/separations10080432 - 29 Jul 2023
Viewed by 256
Abstract
The development of shale gas reservoirs often involves the utilization of horizontal well segmental multi-stage fracturing techniques. However, these reservoirs face challenges, such as rapid initial wellhead pressure and production decline, leading to extended periods of low-pressure production. To address these issues and [...] Read more.
The development of shale gas reservoirs often involves the utilization of horizontal well segmental multi-stage fracturing techniques. However, these reservoirs face challenges, such as rapid initial wellhead pressure and production decline, leading to extended periods of low-pressure production. To address these issues and enhance the production during the low-pressure stage, pressurized mining is considered as an effective measure. Determining the appropriate pressurization target and method for the shale gas wells is of great practical significance for ensuring stable production in shale gas fields. This study takes into account the current development status of shale gas fields and proposes a three-stage pressurization process. The process involves primary supercharging at the center station of the block, secondary supercharging at the gas collecting station, and the introduction of a small booster device located behind the platform separator and in front of the outbound valve group. By incorporating a compressor, the wellhead pressure can be reduced to 0.4 MPa, resulting in a daily output of 12,000 to 14,000 cubic meters from the platform. Using a critical liquid-carrying model for shale gas horizontal wells, this study demonstrates that reducing the wellhead pressure decreases the critical flow of liquid, thereby facilitating the discharge of the accumulated fluid from the gas well. Additionally, the formation pressure of shale gas wells is estimated using the mass balance method. This study calculates the cumulative production of different IPR curves based on the formation pressure. It develops a dynamic production decline model for gas outlet wells and establishes a relationship between the pressure depletion of gas reservoirs and the cumulative gas production before and after pressurization of H10 −2 and H10 −3 wells. The final estimated ultimate recovery of two wells is calculated. In conclusion, the implementation of multi-stage pressurization, as proposed in this study, effectively enhances the production of, and holds practical significance for, stable development of shale gas fields. Full article
(This article belongs to the Topic Oil, Gas and Water Separation Research)
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Article
Separation of (2E,4E)-deca-2,4-dienal from a Biocatalytic Reaction Mixture Using Hydrophobic Adsorbents
Separations 2023, 10(8), 431; https://doi.org/10.3390/separations10080431 - 29 Jul 2023
Viewed by 288
Abstract
Biocatalytic oxidation of a fatty acid preparation by enzymes released from a plant extract provided (2E,4E)-deca-2,4-dienal (2,4-DDAL), a valuable natural aroma. The post-reaction mixture contained several other compounds, from which 2,4-DDAL must be recovered. These included the main by-product trans-2-hexenal (2-HAL) and the [...] Read more.
Biocatalytic oxidation of a fatty acid preparation by enzymes released from a plant extract provided (2E,4E)-deca-2,4-dienal (2,4-DDAL), a valuable natural aroma. The post-reaction mixture contained several other compounds, from which 2,4-DDAL must be recovered. These included the main by-product trans-2-hexenal (2-HAL) and the unreacted substrate composed mainly of linoleic, palmitic, and oleic acids. The adsorption capacity and selectivity of 17 hydrophobic adsorbents were examined in batch equilibrium experiments. The highest binding capacity for 2,4-DDAL was around 30 mg/g. Due to a large excess of fatty acids in the mixture, the total adsorbed amounts of other components analyzed reached the values up to 150 mg/g. In addition, 2-HAL was always adsorbed more strongly than 2,4-DDAL, whereas fatty acids were mostly not adsorbed as effectively. The best-performing adsorbent, AmberLite FPX66, had a selectivity ratio of 6 for 2,4-DDAL with respect to the key impurity and linoleic acid. Ethanol, isopropanol, and acetone were examined as potential desorbents using batch adsorption experiments on AmberLite FPX66 from 2,4-DDAL solutions in organic solvents. Ethanol was found to be the best choice. Based on the batch equilibrium data, a column elution experiment was performed to purify 2,4-DDAL from the biocatalytic reaction mixture using elution with 96% ethanol. Full article
(This article belongs to the Section Purification Technology)
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Article
Superior Removal of Toxic Cr(VI) from Wastewaters by Natural Pine Bark
Separations 2023, 10(8), 430; https://doi.org/10.3390/separations10080430 - 28 Jul 2023
Viewed by 153
Abstract
Hexavalent chromium (Cr(VI)) is one of the most toxic heavy metals found in industrial wastewater, so many researchers are working to develop efficient and environmentally friendly removal methods. It has been reported that natural biomass and its derivatives can be used to treat [...] Read more.
Hexavalent chromium (Cr(VI)) is one of the most toxic heavy metals found in industrial wastewater, so many researchers are working to develop efficient and environmentally friendly removal methods. It has been reported that natural biomass and its derivatives can be used to treat wastewaters containing Cr(VI). However, biomass with sufficient Cr(VI) removal performance to replace the existing chemical method, which is cheap and simple, has not been reported yet. This study reports that inexpensive, abundant, and commercially available pine bark has the highest Cr(VI) removal capacity (i.e., 376.3 mg/g) compared to biomass reported elsewhere. This value is six times higher than the theoretical value of an inorganic reducing agent (iron(II) sulfate heptahydrate). The main mechanism of Cr(VI) removal by pine bark was clearly identified through kinetic experiments, Fourier-transform infrared spectrometer, and X-ray photoelectron spectroscopy analyses, which were used to study the compositions, functional groups, and bonding states of pine bark. It was found that pine bark consists of various acidic functional groups that can act as electron donors to promote the removal of Cr(VI) through redox reactions. In conclusion, pine bark may be a promising candidate for the removal of Cr(VI) from wastewater, owing to its excellent removal capacity. Full article
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Communication
Isolation and Structural Elucidation of Unreported Prenylhydroquinone Glycoside from Sedum kamtschaticum Leaves and Its Effect on Hyperphosphorylated Tau Production in Aβ1–42-Treated SH-SY5Y Cells
Separations 2023, 10(8), 428; https://doi.org/10.3390/separations10080428 - 28 Jul 2023
Viewed by 235
Abstract
Sedum kamtschaticum Fischer, of the Crassulaceae family, is a perennial and medicinal plant used in Asian folk medicine to alleviate inflammatory disease and improve blood circulation. As part of our ongoing exploration into natural products, seeking to identifying bioactive compounds, we characterized, identified, [...] Read more.
Sedum kamtschaticum Fischer, of the Crassulaceae family, is a perennial and medicinal plant used in Asian folk medicine to alleviate inflammatory disease and improve blood circulation. As part of our ongoing exploration into natural products, seeking to identifying bioactive compounds, we characterized, identified, and isolated an unreported bioactive compound, prenylhydroquinone glycoside (1), which we named kirinchoside from S. kamtschaticum leaves. Using high-resolution (HR)-ESIMS, NMR spectroscopic data, and enzymatic hydrolysis, followed by LC–MS analysis, we determined the structure of this isolated compound. Despite a previous report on the planar structure of compound 1 (kirinchoside), the absolute configuration of 1 had not been verified. We investigated the effects of kirinchoside on hyperphosphorylated tau (p-tau) accumulation, a hallmark of Alzheimer’s disease (AD) progression. We observed that treatment with 5 μM kirinchoside suppressed p-tau levels by 16.9% in amyloid β (Aβ)1–42-treated SH-SY5Y cells, compared to the negative control. These findings indicate that kirinchoside, an unreported prenylhydroquinone glycoside found in S. kamtschaticum leaves, could be a candidate preventive agent against AD via inhibition of p-tau accumulation. Full article
(This article belongs to the Section Purification Technology)
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