Separations

14 pages, 2200 KiB

Open AccessArticle

Hydrogen–Water Isotope Catalytic Exchange Process Analysis by Simulation

by Jingwei Hou, Jiamao Li, Chengjian Xiao, Heyi Wang and Shuming Peng

Separations 2024, 11(7), 219; https://doi.org/10.3390/separations11070219 - 22 Jul 2024

Viewed by 706

The hydrogen–water isotope catalytic exchange process has been widely applied in the tritium-containing water treatment process. It can be compared and analyzed conveniently with process simulation software. In this study, the catalytic exchange process was simulated by Aspen Plus software (V11). According to [...] Read more.

The hydrogen–water isotope catalytic exchange process has been widely applied in the tritium-containing water treatment process. It can be compared and analyzed conveniently with process simulation software. In this study, the catalytic exchange process was simulated by Aspen Plus software (V11). According to the simulation results, the main reaction process was that HDO in the liquid phase converts into HD in the gas phase, and the reaction mainly occurred at the bottom of the column, exhibiting a two-orders-of-magnitude-higher reaction amount compared to that observed in the top section. Different side reactions occur at distinct positions along the column, exhibiting a reaction amount that is lower by one to two orders of magnitude compared to the main reaction and aligning in the same direction as the main reaction. The optimum operating temperature is 60~80 °C, with the best performance observed at 70 °C, because of the large reaction equilibrium constant and the suitable ratio of vapor to hydrogen (1:4~1:1.5) in the gas phase. The influence of the residence time was investigated by introducing reaction kinetic equations. The residence time should be more than 1 s to ensure an adequate reaction. The influence of operating conditions on the hydrogen–water isotope catalytic exchange process can be deeply investigated by process simulation, and more mass transfer process quantities can be obtained. It plays a promoting role in guiding the process design and condition optimization. Full article

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17 pages, 2923 KiB

Open AccessArticle

Comparison of Scenedesmus obliquus in CO₂ Capture, Biolipid Production and Nutrient Removal

by Wenwen Cao, Hongfei Yu, Wei Dong, Zijia Rong, Dianbao Peng, Fukun Chen and Lixin Li

Separations 2024, 11(7), 218; https://doi.org/10.3390/separations11070218 - 22 Jul 2024

Viewed by 1001

Abstract

The cultivation of microalgae from municipal wastewater, while simultaneously removing nutrients from the water column, has the potential to aid biodiesel production and carbon dioxide fixation, thereby alleviating the pressure of energy shortages. In this research, different ratios of sodium bicarbonate and glucose [...] Read more.

The cultivation of microalgae from municipal wastewater, while simultaneously removing nutrients from the water column, has the potential to aid biodiesel production and carbon dioxide fixation, thereby alleviating the pressure of energy shortages. In this research, different ratios of sodium bicarbonate and glucose were used to prepare simulated municipal wastewater. The results demonstrated that microalgae were most effectively treated under one-stage direct treatment conditions. During direct culture, the most effective treatment was observed for IAA-3, which exhibited a dry weight of 1.4363 g/L and a lipid content of 25.05% after stimulation with 0.0005 M NaHCO₃. In contrast, NaHCO₃-2 demonstrated optimal performance during the secondary culture, with a dry weight of 1.6844 g/L and a lipid content of 18.05%. Finally, the economic, social and environmental benefits of direct treatment (IAA-3) and secondary treatment NaHCO₃-2 were analyzed. The benefits of direct treatment were found to be USD 0.50989/L, while those of secondary treatment were USD 0.43172/L. For each tonne of municipal wastewater treated, the carbon sequestration benefits of IAA-3 during direct treatment and NaHCO₃-2 during secondary treatment were USD 0.45645 and USD 0.85725, respectively. Full article

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9 pages, 1567 KiB

Open AccessArticle

Synthesis and Biological Evaluation of Desacetylmatricarin Derivatives Isolated from Basin Big Sagebrush

by N. Evelin Paucar, Shanae Van Leuven, Karl De Jesus, Srinath Pashikanti, Sameena Mateen, Samjhana Pradhan and Kavita Sharma

Separations 2024, 11(7), 217; https://doi.org/10.3390/separations11070217 - 19 Jul 2024

Viewed by 586

Abstract

Desacetylmatricarin, a sesquiterpene lactone (SL), is the major component extracted from the aerial parts of basin big sagebrush (Artemisia tridentata subsp. tridentata). The medicinal benefits of desacetylmatricarin have not been fully exploited; thus, the current study is an exploratory study to [...] Read more.

Desacetylmatricarin, a sesquiterpene lactone (SL), is the major component extracted from the aerial parts of basin big sagebrush (Artemisia tridentata subsp. tridentata). The medicinal benefits of desacetylmatricarin have not been fully exploited; thus, the current study is an exploratory study to assess its biological activity as a potential source for anti-cancer properties. Herein, we have synthesized desacetylmatricarin derivatives using reported methodologies and examined their anti-cancer properties by submitting the synthesized compounds to the National Cancer Institute (NCI). Our previous studies on the evaluation of the biological activity of the SLs isolated from the basin big sagebrush against the NCI-60 cancer cell line screening expanded our work on derivatizing desacetylmatricarin. All of the compounds synthesized from desacetylmatricarin, which was isolated and purified from the basin big sagebrush, were obtained in high yields. The structures of the synthesized desacetylmatricarin derivatives were confirmed by NMR experiments. These compounds were then evaluated against the NCI-60 cancer cell line screening. NCI-60 cancer cell line screening revealed that some of the chemically modified desacetylmatricarin derivatives showed greater biological activity as compared to the natural precursor in a one-dose assay. Full article

(This article belongs to the Special Issue Extraction and Analysis of Chemical Compositions of Natural Products and Plants)

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13 pages, 3188 KiB

Open AccessArticle

Enhanced Degradation of Carbamazepine from Constructed Wetlands with a PEC System Based on an Anode of N-TiO₂ Nanocrystal-Modified TiO₂ Nanotubes and an Activated Carbon Photocathode

by Xiongwei Liang, Shaopeng Yu, Bo Meng, Jia Liu, Chunxue Yang, Chuanqi Shi and Junnan Ding

Separations 2024, 11(7), 216; https://doi.org/10.3390/separations11070216 - 19 Jul 2024

Viewed by 692

Abstract

We used the Vienna ab initio Simulation Package (VASP), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance (DRS) to optimize anode material for a photoelectric catalytic system. After screening how the doping of TiO₂ by N and S affects its photoelectric properties, N-doped [...] Read more.

We used the Vienna ab initio Simulation Package (VASP), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance (DRS) to optimize anode material for a photoelectric catalytic system. After screening how the doping of TiO₂ by N and S affects its photoelectric properties, N-doped TiO₂ was selected to fabricate the photoelectron catalytic (PEC) system. TiO₂ nanotubes modified by N-doped TiO₂ nanocrystals and activated carbon were used as an anode and as a photocathode, respectively, to decompose carbamazepine in water samples from the constructed wetlands. The calculations showed that the N-TiO₂ NCs/TNTAs-AC/PTFE system had the highest content of •OH. The highest carbamazepine removal rate under the N-TiO₂ NCs/TNTAs-AC/PTFE composite presence was at pH = 8, and 69% of carbamazepine was removed within 180 min of the constructed wetland water treatment at pH = 7.8. The PEC system containing modified (with nano N-TiO₂) TiO₂ nanotubes as an anode and activated carbon as a photocathode can effectively decompose carbamazepine in the constructed wetlands. Full article

(This article belongs to the Special Issue Advanced Nitrogen Removal Process in Adsorption and Removal of Pollutants)

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18 pages, 2103 KiB

Open AccessArticle

Removal of Emerging Contaminants from Water by Using Carbon Materials Derived from Tingui Shells

by Débora dos Santos, Wardleison Moreira, Thiago de Araújo, Maria Bernardo, Isabel Fonseca, Indianara Ostroski and Maria Angélica de Barros

Separations 2024, 11(7), 215; https://doi.org/10.3390/separations11070215 - 12 Jul 2024

Viewed by 926

Abstract

This study explored the adsorption of acetaminophen and caffeine using CO₂-activated biochar (BT-CO₂) and hydrochar (HT-CO₂) derived from Tingui shell biomass. The experimental data from kinetic and equilibrium adsorption tests were employed in batch and fixed-bed systems. [...] Read more.

This study explored the adsorption of acetaminophen and caffeine using CO₂-activated biochar (BT-CO₂) and hydrochar (HT-CO₂) derived from Tingui shell biomass. The experimental data from kinetic and equilibrium adsorption tests were employed in batch and fixed-bed systems. In the batch system, a specific amount of the adsorbent was added to a known volume of the solution, and the mixture was agitated for a set period to allow adsorption to occur. In the fixed-bed system, the solution was passed through a column packed with the adsorbent, allowing for continuous adsorption. These systems pave the way for future research. The findings revealed that HT-CO₂ exhibited a greater surface area and a higher presence of oxygen-containing functional groups than BT-CO₂. These functional oxygen groups had a notable impact on the adsorption capacity of the adsorbents for pharmaceutical substances. In the batch systems, BT-CO₂ demonstrated a maximum adsorption capacity of 221.4 mg g⁻¹ for acetaminophen and 162.7 mg g⁻¹ for caffeine, while HT-CO₂ exhibited higher capacities of 383.2 mg g⁻¹ for acetaminophen and 189.7 mg g⁻¹ for caffeine. In the fixed bed configuration, HT-CO₂ displayed a maximum adsorption capacity of 82.2 mg g⁻¹ for acetaminophen and 45.60 mg g⁻¹ for caffeine. The predominant mechanisms involved in the removal of acetaminophen and caffeine were identified as H-bonding and π-π bonds. These results underscore the promising potential of these carbons as effective adsorbents for treating water contaminated with pharmaceutical residues, inspiring further exploration in this field and offering hope for the future of water treatment by providing a solid foundation for future research and development. Full article

(This article belongs to the Special Issue Separation Technologies and Evaluation Methodologies in Recycling Wastewater for SDG 6)

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16 pages, 3055 KiB

Open AccessArticle

The Application of Polysaccharide Chiral Columns for the Separation of Fluorinated and Protonated Liquid Crystalline Racemic Esters

by Edyta Wojda and Magdalena Urbańska

Separations 2024, 11(7), 214; https://doi.org/10.3390/separations11070214 - 12 Jul 2024

Viewed by 564

Abstract

The subject of this study was to compare the enantioseparation of fourteen racemic esters that are liquid crystals. This study aimed to determine the difference in the enantioseparation of mixtures with protonated and fluorinated aliphatic chains and those with different orders of occurrence [...] Read more.

The subject of this study was to compare the enantioseparation of fourteen racemic esters that are liquid crystals. This study aimed to determine the difference in the enantioseparation of mixtures with protonated and fluorinated aliphatic chains and those with different orders of occurrence of benzene rings (benzoates and biphenylates). This research was carried out on two chiral polysaccharide columns: amylose tris(3-chloro-5-methylphenylcarbamate) (ReproSil Chiral MIG) and cellulose tris(3,5-dichlorophenylcarbamate) (ReproSil Chiral MIC). The columns were evaluated in HPLC separation. The analyses were performed in the normal- and reversed-phase systems. The mobile phase consisted of different solvent systems (acetonitrile/water and n-hexane/2-propanol) in different volume ratios to select optimal separation conditions. The main parameter evaluated in separating racemic mixtures was the resolution—Rs. All measurements were performed at 25 °C. The elution order was also determined. The highest value of resolution (over 11) and selectivity (over 3) was obtained for the ReproSil Chiral MIG column and the volume ratio of ACN:H₂O (95:5 v/v). Full article

(This article belongs to the Section Chromatographic Separations)

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11 pages, 1408 KiB

Open AccessArticle

The Effect of Yinchenhao Decoction on the Pharmacokinetic Profile of Futibatinib by HPLC-MS/MS

by Chunfu Wang, Songmao Liang, Jiachen Xu, Yingfan Zhai, Jianghui Chen and Xiangjun Qiu

Separations 2024, 11(7), 213; https://doi.org/10.3390/separations11070213 - 11 Jul 2024

Cited by 1 | Viewed by 572

Abstract

Futibatinib is an excellent fibroblast growth factor receptor 1–4 (FGFR 1–4) inhibitor that exhibits selective anti-tumor activeness against FGFR-deregulated tumors. A new high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) technique for the quantitative analysis of futibatinib in beagle dog plasma was developed, and the [...] Read more.

Futibatinib is an excellent fibroblast growth factor receptor 1–4 (FGFR 1–4) inhibitor that exhibits selective anti-tumor activeness against FGFR-deregulated tumors. A new high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) technique for the quantitative analysis of futibatinib in beagle dog plasma was developed, and the effect of Yinchenhao decoction (YCHD) on the pharmacokinetics of futibatinib was evaluated. After processing plasma samples with ethyl acetate extraction in the alkaline condition of sodium carbonate, a C18 column (4.6 mm × 150, 5 μm) was used to accomplish the separation of futibatinib and ripretinib (internal standard, ISTD), with the mobile phase consisting of methanol and 0.1% formic acid in water (60:40). The scanning method adopted a multiple reaction monitoring (MRM) mode with positive ion detection through the triple quadrupole mass spectrometer. The ion transitions for futibatinib and IS were m/z 419.20 → 296.15 and m/z 510.36 → 417.00, respectively. Futibatinib displayed excellent linearity in the range of 1–200 ng/mL. Neither inter-day nor intra-day precision exceeded 6.3%. The %RE values for accuracy ranged from −3.1% to 0.9%. The recovery, stability, and matrix effect of futibatinib also complied with the guidelines for the validation of quantitative analysis methods for biological samples in the 2020 edition of the Chinese Pharmacopoeia. In combination with YCHD, the C_max of futibatinib increased by 40.84% compared to futibatinib dosage alone., and the AUC_(0–t) and AUC_(0–∞) of futibatinib increased by 78.06% and 82.71%, respectively. The Vd and CL of futibatinib were reduced by 20.05% and 40.85%, respectively. T_1/2 was extended from 3.88 h to 5.26 h. The results indicated that YCHD could affect the pharmacokinetics of futibatinib and increase the plasma exposure of futibatinib. If YCHD is administered along with futibatinib, this study gives a first impression how pharmacokinetics and toxicokinetics would change. Full article

(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)

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19 pages, 12938 KiB

Open AccessArticle

The Mechanism of Air Blocking in the Impeller of Multiphase Pump

by Sicong Zhang, Wei Han, Tongqing Xue, Pan Qiang, Rennian Li and Jiandong Mi

Separations 2024, 11(7), 212; https://doi.org/10.3390/separations11070212 - 10 Jul 2024

Viewed by 720

Abstract

The exploitation and transportation of deep-sea and remote oil and gas fields have risen to become important components of national energy strategies. The gas–liquid separation and gas blocking caused by the large density difference between the gas and liquid phases are the primary [...] Read more.

The exploitation and transportation of deep-sea and remote oil and gas fields have risen to become important components of national energy strategies. The gas–liquid separation and gas blocking caused by the large density difference between the gas and liquid phases are the primary influencing factors for the safe and reliable operation of gas–liquid mixed transportation pump systems. This paper takes the independently designed single-stage helical axial-flow mixed transportation pump compression unit as the research object. Through numerical simulation, the internal flow of the mixed transportation pump is numerically calculated to study the aggregation and conglomeration of small gas clusters in the flow passage hub caused by gas–liquid phase separation, influenced by the shear flow of phase separation, forming axial vortices at the outlet where gas clusters gather in the flow passage. The work performed by the impeller on the gas clusters is insufficient to overcome the adverse pressure gradient formed at the outlet of the flow passage due to the gathering of the liquid phase in adjacent flow passages, resulting in the phenomenon of gas blocking, with vortex gas clusters lingering near the hub wall of the flow passage. Full article

(This article belongs to the Topic Oil, Gas and Water Separation Research)

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13 pages, 2509 KiB

Open AccessArticle

Exploratory Study on Distinguishing Dendrobium Stem and Five Species of Dendrobium Using Heracles Neo Ultra-Fast Gas Phase Electronic Nose

by Yuping Dai, Dan Huang, Ye He, Yun Xiang and Shunxiang Li

Separations 2024, 11(7), 211; https://doi.org/10.3390/separations11070211 - 10 Jul 2024

Viewed by 598

Abstract

Dendrobium stem is a valuable food with medicinal and edible properties. Due to its high medicinal value and price, closely related Dendrobium varieties are often sold as imitations on the market. Therefore, there is an urgent need to develop new methods that can [...] Read more.

Dendrobium stem is a valuable food with medicinal and edible properties. Due to its high medicinal value and price, closely related Dendrobium varieties are often sold as imitations on the market. Therefore, there is an urgent need to develop new methods that can quickly identify Dendrobium stem and its closely related species. The Heracles Neo ultra-fast gas phase electronic nose was used in this study to determine and analyze the composition and contents of volatile organic compounds (VOCs) in Dendrobium stem and samples of five other species closely related to it. A total of 20 VOCs were identified, and a fingerprint map of the VOCs was constructed. Principal component analysis (PCA), Euclidean distance, and other methods were used to comprehensively process and analyze the obtained VOC information. The AroChemBase database was also used for qualitative analysis of the compounds. The results showed that there are significant differences in the odor fingerprint spectra of Dendrobium stem and the five other closely related species. The main types of compounds in Dendrobium stem and its five closely related species were organic esters, aldehydes, ketones, and olefins. Among them, 3-methylbutanal and n-butanol were characteristic compounds of the Dendrobium stem sample, while the VOCs acetonitrile and trometamol were present in the five related Dendrobium species samples. The Heracles Neo ultra-fast gas phase electronic nose can quickly and accurately identify Dendrobium stem and its five closely related species. It can also be used for the quality evaluation of Dendrobium stem, providing a theoretical reference for reducing the phenomenon of medicinal confusion in the Dendrobium stem market. Full article

(This article belongs to the Collection Recent Trends in the Separation of Natural Products and Pharmaceuticals)

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18 pages, 6746 KiB

Open AccessArticle

Optimization of Extraction Process of Total Alkaloids from Thalictrum delavayi Franch. and Their Therapeutic Potential on Pulmonary Infection Caused by Klebsiella pneumoniae and Escherichia coli

by Li Chen, Mochezai Aku, Zhaobin Xia, Shiyu Yang, Danjiao Yang and Chaoxi Chen

Separations 2024, 11(7), 210; https://doi.org/10.3390/separations11070210 - 8 Jul 2024

Viewed by 858

Abstract

Bacterial co-infected pneumonia is an acute inflammatory reaction of the lungs mainly caused by Gram-negative bacteria. Antibiotics are urgently important but have the disadvantage of antibacterial resistance, and alternative treatments with medicinal plants are attractive. On the Qinghai–Tibet Plateau, Thalictrum delavayi Franch. ( [...] Read more.

Bacterial co-infected pneumonia is an acute inflammatory reaction of the lungs mainly caused by Gram-negative bacteria. Antibiotics are urgently important but have the disadvantage of antibacterial resistance, and alternative treatments with medicinal plants are attractive. On the Qinghai–Tibet Plateau, Thalictrum delavayi Franch. (T. delavayi) is an important member of the buttercup family (Ranunculaceae), is rich in alkaloids and has been used in folk medicine for thousands of years. In this study, the extraction process of total alkaloids from the whole T. delavayi plant was optimized and the extract’s therapeutic potential against pulmonary infection caused by Klebsiella pneumoniae and Escherichia coli was investigated. The results showed that the optimum experimental conditions for the total alkaloids (2.46%) from T. delavayi were as follows: hydrochloric acid volume fraction of 0.8%, solid–liquid ratio of 1:12 and sonication time of 54 min. The treatment reduced bacterial counts, white blood cell counts and inflammatory cell classification in bronchoalveolar lavage fluid (BALF) and the levels of inflammatory cytokines interleukin-4 (IL-4), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), procalcitonin (PCT) and C-reactive protein (CRP), procalcitonin (PCT) and C-reactive protein (CRP) in the serum in experimental groups. The results in our experimental preliminary work suggested that the total alkaloids from T. delavayi had therapeutic effects on mice with Klebsiella pneumoniae and Escherichia coli mixed infectious pneumonia, providing experimental support for the plant’s therapeutic potential in treating pulmonary infections caused by Klebsiella pneumoniae and Escherichia coli. Full article

(This article belongs to the Special Issue Bioactive Compounds from Natural Sources: Extraction, Characterization, Evaluation and Application)

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21 pages, 4175 KiB

Open AccessArticle

Isolation of Arborescin from Artemisia absinthium L. and Study of Its Antioxidant and Antimicrobial Potential by Use of In Vitro and In Silico Approaches

by Asmae Hbika, Amine Elbouzidi, Mohamed Taibi, Safae Ouahabi, El Hassania Loukili, Abdelhamid Bouyanzer, Meryem Idrissi Yahyaoui, Abdeslam Asehraou, Naoufal El Hachlafi, Ahmad Mohammad Salamatullah, Mohammed Bourhia, Samir Ibenmoussa, Mohamed Addi and Elkhadir Gharibi

Separations 2024, 11(7), 209; https://doi.org/10.3390/separations11070209 - 5 Jul 2024

Cited by 1 | Viewed by 837

Abstract

This study focused on developing an innovative, straightforward, and economical method utilizing a mixture of readily available solvents to extract arborescin (C₂OH₂OO₈) crystals from Artemisia absinthium L. (A. absinthium). The structural elucidation and characterization were [...] Read more.

This study focused on developing an innovative, straightforward, and economical method utilizing a mixture of readily available solvents to extract arborescin (C₂OH₂OO₈) crystals from Artemisia absinthium L. (A. absinthium). The structural elucidation and characterization were conducted using a suite of techniques including IR spectroscopy, CNHSO elemental analysis, scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), and mass spectroscopy (MS). Density functional theory (DFT) calculations were employed to determine the molecular properties. Antioxidant activity was measured using the DPPH radical scavenging assay and the β-carotene bleaching test. Antimicrobial efficacy was assessed against four bacterial strains and three fungal strains. The molecular docking approach was employed to predict the probable binding patterns and affinities of arborescin with specific target biomolecules. Employing an array of analytical techniques, examination of the isolated crystal from A. absinthium. led to its comprehensive structural elucidation. IR spectroscopy revealed the presence of distinctive functional groups, including a carbonyl group within the γ-lactone and an epoxy group. CNHSO elemental analysis verified that the crystal contained only carbon, hydrogen, and oxygen, a finding corroborated by SEM-EDS analysis, consistent with the molecular structure of arborescin. Additionally, mass spectrometry confirmed the identity of the compound as arborescin, with a molecular ion with a mass m/z = 248. Quantum-Chemical Descriptors revealed that arborescin is resistant to elementary decomposition under standard conditions. Although arborescin demonstrates a relatively low antioxidant capacity, with an IC50 of 5.04 ± 0.12 mg/mL in the DPPH assay, its antioxidant activity in the β-carotene bleaching test was found to be 3.64%. Remarkably, arborescin effectively inhibits the growth of Staphylococcus aureus and Listeria innocua at low concentrations (MIC = 166 µg/mL). Additionally, it exhibits significant antifungal activity against Candida glabrata, with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 83 µg/mL and 166 µg/mL, respectively. In this study, arborescin exhibited a robust docking score of −8.1 kcal/mol, indicating a higher affinity compared to ciprofloxacin. This suggests that arborescin has significant potential as a potent antibacterial agent. Full article

(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)

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15 pages, 2405 KiB

Open AccessArticle

The Volatile Compounds Composition of Different Parts of Wild Kazakhstan Sedum ewersii Ledeb.

by Tatyana Kobylina, Andriy Novikov, Gulbanu Sadyrova, Elzira Kyrbassova, Saltanat Nazarbekova, Elmira Imanova, Meruyert Parmanbekova and Bekzat Tynybekov

Separations 2024, 11(7), 208; https://doi.org/10.3390/separations11070208 - 5 Jul 2024

Cited by 1 | Viewed by 770

Abstract

The chemical composition of Sedum ewersii Ledeb., a plant indigenous to Kazakhstan and traditionally utilized in folk medicine, was comprehensively investigated, with a focus on its various plant parts. Fresh samples collected in May 2023 from the Almaty region underwent hydrodistillation to extract [...] Read more.

The chemical composition of Sedum ewersii Ledeb., a plant indigenous to Kazakhstan and traditionally utilized in folk medicine, was comprehensively investigated, with a focus on its various plant parts. Fresh samples collected in May 2023 from the Almaty region underwent hydrodistillation to extract volatile components, followed by analysis using gas chromatography coupled with mass spectrometric detection, which identified a total of 71 compounds across different plant parts, including the root (underground part), root (aerial part), leaf, stem, and flowering aerial part. The predominant biologically active compound identified across all plant parts was Ethyl α-D-glucopyranoside. Monoterpenes, recognized as primary secondary metabolites, were notably abundant in each plant part, with varying compositions: the root (underground part) contained 28.58% aliphatic monoterpenes, 54.41% oxygenated monoterpenoids, 1.42% diterpenoids, and 15.59% other compounds; the root (aerial part) exhibited 1.34% aliphatic monoterpenes, 31.28% oxygenated monoterpenoids, 6.16% diterpenoids, and 61.22% other compounds; the stem and leaves showed 3.06% aliphatic monoterpenes, 21.49% oxygenated monoterpenoids, 17.99% diterpenoids, and 57.46% other compounds; and the flowering aerial part displayed 8.20% aliphatic monoterpenes, 53.18% oxygenated monoterpenoids, 23.75% diterpenoids, and 14.87% other compounds. Diterpenes, particularly Phytol, were prominently present in the leaf, stem, and flowering aerial parts. Additionally, a diverse array of organic acids, ketones, and phenolic compounds were identified across the plant parts, each potentially offering distinct pharmacological benefits. The presence of exclusive compounds in specific plant parts, such as Dihydroxyacetone in the root (aerial part), underscored the pharmacological diversity of S. ewersii. This study provides valuable insights into the chemical diversity and pharmacological potential of S. ewersii, suggesting promising applications in pharmaceutical and medicinal fields. Further research aimed at elucidating the individual and synergistic pharmacological effects of these compounds is crucial to fully harness the therapeutic benefits of this plant. Full article

(This article belongs to the Special Issue Research Progress for Isolation of Plant Active Compounds)

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18 pages, 2009 KiB

Open AccessArticle

Development and Validation of a Quantitative Analysis of Water-Soluble Vitamins Using High-Performance Thin-Layer Chromatography and Its Application to the Analysis of Nutraceuticals

by K. M. Yasif Kayes Sikdar, Md Khairul Islam, Tomislav Sostaric, Lee Yong Lim and Cornelia Locher

Separations 2024, 11(7), 207; https://doi.org/10.3390/separations11070207 - 4 Jul 2024

Viewed by 1160

Abstract

In this study, a high-performance thin-layer chromatography (HPTLC)-based method was developed for the quantification of five water-soluble vitamins, B₂, B₃, B₆, B₁₂, and C, using ethanol–water (70:30, v/v) as the mobile phase. [...] Read more.

In this study, a high-performance thin-layer chromatography (HPTLC)-based method was developed for the quantification of five water-soluble vitamins, B₂, B₃, B₆, B₁₂, and C, using ethanol–water (70:30, v/v) as the mobile phase. The method was validated according to the International Conference on Harmonisation (ICH) guidelines and the limits of detection/limits of quantification were determined as 5.27/15.97 ng (Vitamin B₂), 13.03/39.47 ng (Vitamin B₃), 59.61/180.64 ng (Vitamin B₆), 14.17/42.93 ng (Vitamin B₁₂), and 119.27/361.42 ng (Vitamin C) per band, respectively. The usefulness of the validated method for quality control was demonstrated with the successful quantitative analysis of the five vitamins in a range of nutraceuticals. Full article

(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)

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18 pages, 4369 KiB

Open AccessArticle

Effects of Extraction Methods on Volatile Oil Profiles of Cinnamomi ramulus–Zingiberis rhizoma recens Couplet Medicines

by Xiaodong Xin, Xinnong Li, Jiabao Chen, Chuanghui Shen, Xiaohan Shi, Lei Wang and Chunhua Li

Separations 2024, 11(7), 206; https://doi.org/10.3390/separations11070206 - 2 Jul 2024

Viewed by 763

Abstract

Cinnamomi ramulus (CR, Guizhi in Chinese) and Zingiberis rhizoma recens (ZRR, Shengjiang in Chinese) are couplet medicines (drug pairs or drug combinations) in traditional Chinese medicine prescriptions. They contain a high amount of volatile oils which endow them with unique flavors and pharmacological [...] Read more.

Cinnamomi ramulus (CR, Guizhi in Chinese) and Zingiberis rhizoma recens (ZRR, Shengjiang in Chinese) are couplet medicines (drug pairs or drug combinations) in traditional Chinese medicine prescriptions. They contain a high amount of volatile oils which endow them with unique flavors and pharmacological activities. Extraction methods have a great influence on the extraction efficiency and composition of volatile oils. Firstly, the volatile oils of CR and ZRR were extracted by steam distillation (SD) and analyzed by GC-MS to obtain their chemical profiles. In total, 35 and 55 compounds were identified in the volatile oils of CR and ZRR, respectively. In order to find a suitable extraction method for the couplet medicine CR-ZRR, subsequently, steam distillation (SD), azeotropic distillation (AD) and supercritical fluid extraction (SFE) were applied to extract the volatile oils from CR-ZRR. The average extraction yields by SD, AD and SFE were 0.573%, 0.62% and 2.135%, respectively. The chemical composition of the volatile oils was then analyzed by GC-MS. In total, 73, 59 and 71 compounds were identified from the extracts obtained by SD, AD and SFE, respectively. Principal component analysis (PCA) and OPLS-DA showed that citral, (E)-cinnamaldehyde dimethyl acetal, zingiberene, cinnamaldehyde and β-sesquiphellandrene were the main contributors to distinguish the volatile oils that were obtained by different processes. Considering the chemical diversity and the total content of the main bioactive components of the volatiles oils, SD was more suitable for CR-ZRR volatile oil extraction. This study provides a basis for elucidating the chemical composition and suitable extraction method for the volatile oils of CR-ZRR. Full article

(This article belongs to the Special Issue Extraction and Analysis of Chemical Compositions of Natural Products and Plants)

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29 pages, 1668 KiB

Open AccessReview

Methods of Analysis of Phytoestrogenic Compounds: An Up-to-Date of the Present State

by Ines Adam-Dima, Andreea Alexandra Olteanu, Octavian Tudorel Olaru, Daniela Elena Popa and Carmen Purdel

Separations 2024, 11(7), 205; https://doi.org/10.3390/separations11070205 - 1 Jul 2024

Viewed by 1066

Abstract

Phytoestrogens, natural compounds with structural similarity to 17-β-estradiol, are known to have potential health benefits, including in hormone-dependent malignancies. The therapeutic interest and some safety concerns observed triggered the need to develop accurate methods to assess their level in different matrices. This narrative [...] Read more.

Phytoestrogens, natural compounds with structural similarity to 17-β-estradiol, are known to have potential health benefits, including in hormone-dependent malignancies. The therapeutic interest and some safety concerns observed triggered the need to develop accurate methods to assess their level in different matrices. This narrative review examines the existing analytical methods used to isolate, quantify, and characterize phytoestrogens and their metabolites in plants, foods, and biological samples. Different conventional and modern extraction techniques, such as ultrasonication-assisted extraction, supercritical fluid extraction, or enzyme-assisted extraction, were presented and compared. The advantages and limitations of the existing analytical methods, such as high-performance liquid chromatography using different sensitive detectors, gas chromatography often coupled with mass spectrometry, and immunoassay methods, are highlighted, along with the need for ongoing research to improve the sensitivity and selectivity of the analysis. Full article

(This article belongs to the Special Issue Analysis and Bioanalysis of Pharmaceuticals: Sample Preparation and Chromatography)

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14 pages, 1557 KiB

Open AccessReview

Ferulic Acid—A Brief Review of Its Extraction, Bioavailability and Biological Activity

by Krystyna Pyrzynska

Separations 2024, 11(7), 204; https://doi.org/10.3390/separations11070204 - 1 Jul 2024

Cited by 1 | Viewed by 1837

Abstract

Ferulic acid is a widespread phenolic compound that occurs in seeds and leaves, both in its free form and conjugated to polysaccharides, carbohydrates, glycoproteins and lignins in the plant cell walls. It exhibits various biological activities, like antioxidant, anticarcinogenic, anti-inflammatory, hepatoprotective, antimicrobial, and [...] Read more.

Ferulic acid is a widespread phenolic compound that occurs in seeds and leaves, both in its free form and conjugated to polysaccharides, carbohydrates, glycoproteins and lignins in the plant cell walls. It exhibits various biological activities, like antioxidant, anticarcinogenic, anti-inflammatory, hepatoprotective, antimicrobial, and antiviral activity, and it modulates enzyme activity. Given these wide potential health benefits, ferulic acid has attracted considerable research interest and may be considered a biomolecule with strong prospects as a functional food ingredient. Great attempts have been made to enhance its extraction process and recovery from natural matrices and agro-industrial wastes for its various applications relating to human health and nutrition. This review presents the recently available information on the extraction methods for quantifying ferulic acid in different samples, along with its bioavailability and stability in processing foods and biological activities. Full article

(This article belongs to the Special Issue Bioactive Compounds in Foods: Separation, Extraction and Application)

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15 pages, 908 KiB

Open AccessReview

Dispersive Liquid–Liquid Micro Extraction: An Analytical Technique Undergoing Continuous Evolution and Development—A Review of the Last 5 Years

by Ivan Notardonato and Pasquale Avino

Separations 2024, 11(7), 203; https://doi.org/10.3390/separations11070203 - 28 Jun 2024

Viewed by 912

Abstract

Over the years, monitoring the quality of the environment, food, and human health has emerged as a fundamental objective of scientific investigation. Various analytical techniques have been devised and continually refined to ensure a high standard of living. Among these methods, dispersive liquid–liquid [...] Read more.

Over the years, monitoring the quality of the environment, food, and human health has emerged as a fundamental objective of scientific investigation. Various analytical techniques have been devised and continually refined to ensure a high standard of living. Among these methods, dispersive liquid–liquid microextraction (DLLME) stands out as a widely used approach to conduct analytical evaluations and pre-concentrations of chemical compounds. This review provides an account of the evolution of DLLME over the past five years (2018–2023). The Scopus search engine was used to search for scientific articles. The selection of relevant articles was carried out according to the criteria described below. Emphasis was placed on the evolution that DLLME has undergone over the years by integrating it with other pre-concentration methods in order to amplify the concentration factor and improve analytical precision. Factors such as solvent dispersion and extraction, dispersion formation, and the recovery of the solvent containing the extracted analytes were examined. Additionally, derivatization systems were evaluated to refine both qualitative and quantitative analysis. These efforts aim to introduce methods that are safe for operators, environmentally friendly, and economical. This review evaluates the advantages and disadvantages displayed by the evolution of this technique in the phases before, during, and after its application. Full article

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13 pages, 5275 KiB

Open AccessArticle

Research on the Influence of the Scaling-up Process on the Flow Structure and Two-Phase Distribution of Gas–Solid Fluidized Beds

by Zhonglin Gao, Jie Wei, Hongyang Wang and Chenyang Zhou

Separations 2024, 11(7), 202; https://doi.org/10.3390/separations11070202 - 28 Jun 2024

Viewed by 572

Abstract

In the continuous scaling-up process of the separating system, a mechanism exists that transforms the behavior of the flow field, resulting in deviations from the original model and conclusions. The paper examined the effects of the scale up of a fluidized bed by [...] Read more.

In the continuous scaling-up process of the separating system, a mechanism exists that transforms the behavior of the flow field, resulting in deviations from the original model and conclusions. The paper examined the effects of the scale up of a fluidized bed by CFD. It was observed that increasing the diameter reduces the amplitude of axial density fluctuations. Similarly, increasing the static height increases the amplitude. Moreover, increasing the static bed height enhances the visibility of the cyclic flow structure of gas and solid phases. The flow structure in large bed diameters is disrupted. The impact of changing the bed diameter on bed density is more significant than the static height. As the bed diameter increases, the bubble disturbance decreases and the aggregation phase gradually disappears while the proportion of the emulsified phase keeps increasing. This study will guide and assist in the future application of separated fluidized beds in industry. Full article

(This article belongs to the Special Issue Research Progress of Gas–Solid Fluidized Dry Separation)

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17 pages, 2949 KiB

Open AccessArticle

Innovative Techniques in Sandalwood Oil Extraction: Optimizing Phenolic and Flavonoid Yields with Subcritical Ethanol

by Weili Zhang, Dwila Nur Rizkiyah and Nicky Rahmana Putra

Separations 2024, 11(7), 201; https://doi.org/10.3390/separations11070201 - 27 Jun 2024

Viewed by 747

Abstract

Sandalwood essential oil, known for its rich content of phenolic and flavonoid compounds, holds great promise for applications in perfumery and medicine. However, traditional production methods have raised concerns regarding their environmental impact and sustainability. This study explored subcritical ethanol extraction as a [...] Read more.

Sandalwood essential oil, known for its rich content of phenolic and flavonoid compounds, holds great promise for applications in perfumery and medicine. However, traditional production methods have raised concerns regarding their environmental impact and sustainability. This study explored subcritical ethanol extraction as a green technique to address these concerns. Under optimized conditions (6.04 MPa, 109 °C, and 2.01 mL/min), maximum oil yield reached 4.04% with substantial total phenolic compounds (TPCs) of 4.11 mg GAE/100 g and total flavonoid compounds (TFCs) of 8.85 mg QE/100 g in the extracted sandalwood oil. Furthermore, the oil displayed notable antioxidant activity AA of 71.68%. The temperature was identified as a significant factor affecting oil yield, TPCs, TFCs, and AA. The fine-tuning of the extraction temperature enhanced the desired characteristics, improving bioactive compound yields and heightening antioxidant potential. This study uses a green extraction technique to contribute to sustainable sandalwood essential oil production. Full article

(This article belongs to the Special Issue Advanced Extraction and Microextraction Techniques and Their Applications in Sample Preparation)

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9 pages, 1904 KiB

Open AccessArticle

A Simple and Efficient Approach to Determine Lithium and Multi-Elements in Lithium-Bearing Clay Minerals through a Partial Extraction Using Ammonium Hydrogen Fluoride

by Feige Zhang, Qinfeng Zhang, Zhigui Chen, Xiaoqing Fang, Xiaoqi Yu, Guangyi Li and Di Chen

Separations 2024, 11(7), 200; https://doi.org/10.3390/separations11070200 - 27 Jun 2024

Viewed by 633

Abstract

Lithium (Li) is vital to the world economy as an irreplaceable element in new-generation sustainable energy applications. Quantifying Li levels in clay minerals, a key new resource, supports extensive mineralization surveys. The major limitation in these analyses is complete decomposition, which often requires [...] Read more.

Lithium (Li) is vital to the world economy as an irreplaceable element in new-generation sustainable energy applications. Quantifying Li levels in clay minerals, a key new resource, supports extensive mineralization surveys. The major limitation in these analyses is complete decomposition, which often requires the use of strong acids and is labor-intensive, particularly in batch processing. This paper presents a partial extraction strategy for quantifying Li and multiple elements, employing ammonium hydrogen fluoride to extract from clay minerals while avoiding the use of various strong acids. Following extraction, the efficiency for Li reaches 98.61%, with values ranging from 62.68% to 91.43% for multiple elements including three major elements (Ca, Fe, Mg) and eleven trace elements (Be, Co, Cr, Cu, Ga, Mn, Ni, P, Rb, Sr, V), demonstrating favorable precision (RSD below 7.34%). This approach offers a promising tool for a simple and efficient batch analysis in the survey of mineralization in Li-bearing clay deposits. Full article

(This article belongs to the Special Issue Advanced Extraction and Microextraction Techniques and Their Applications in Sample Preparation)

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25 pages, 5094 KiB

Open AccessEditor’s ChoiceArticle

Extraction of Bioactive Compound-Rich Essential Oil from Cistus ladanifer L. by Microwave-Assisted Hydrodistillation: GC-MS Characterization, In Vitro Pharmacological Activities, and Molecular Docking

by Naoufal El Hachlafi, Fahd Kandsi, Amine Elbouzidi, Fatima Zahra Lafdil, Ghizlane Nouioura, Emad M. Abdallah, Rhizlan Abdnim, Mohamed Bnouham, Samiah Hamad Al-Mijalli, Hanae Naceiri Mrabti and Kawtar Fikri-Benbrahim

Separations 2024, 11(7), 199; https://doi.org/10.3390/separations11070199 - 27 Jun 2024

Cited by 2 | Viewed by 1281

Abstract

Cistus ladanifer L. is an aromatic and resinous perennial shrub commonly used in Moroccan folk medicine against a range of illnesses including skin problems, diabetes, diarrhea, and inflammation. The current investigation aims to determine the bioactive compounds of C. ladanifer essential oil (CL-Eo) [...] Read more.

Cistus ladanifer L. is an aromatic and resinous perennial shrub commonly used in Moroccan folk medicine against a range of illnesses including skin problems, diabetes, diarrhea, and inflammation. The current investigation aims to determine the bioactive compounds of C. ladanifer essential oil (CL-Eo) extracted by microwave-assisted hydrodistillation and their biological properties using in vitro and molecular docking approaches. The GC-MS analysis identified linderol (17.76%), gamma-terpinene (17.55%), and borneol (13.78%) as main bioactive compounds. CL-Eo significantly inhibited α-amylase (IC₅₀ = 0.41 ± 0.009 mg/mL), α-glucosidase (IC₅₀ = 0.49 ± 0.002 mg/mL) and lipase (IC₅₀ = 0.45 ± 0.004 mg/mL) enzymes. Moreover, CL-Eo showed significant hemoglobin glycation as well as antioxidant capacity as indicated by DPPH, ABTS, Frap and beta-carotene tests. The antimicrobial evaluation used disc-diffusion and microdilution tests in vitro. The results showed that CL-Eo had significant antibacterial activity, particularly against P. mirabilis (17.16 ± 1.04 mm), and moderate effects against L. innocua (13.48 ± 1.65 mm) and E. coli (12.47 ± 0.61 mm). In addition, it demonstrated potent antifungal activity against C. albicans (18.01 ± 0.91 mm) and C. tropicalis (16.45 ± 0.32 mm). The MIC and MBC tests provided confirmation that CL-Eo exhibited potent growth inhibition. The MIC ranged from 0.25 to 8.0% v/v and the MBC or MFC ranged from 0.25 to 16.0% v/v Eo. The tolerance level ratio showed bactericidal and fungicidal effects against tested microbial strains in varying degrees. According to these data, CL-Eo might be suggested as a promising candidate for drug development, specifically for combating candidiasis and diabetes. Full article

(This article belongs to the Special Issue Extraction, Purification and Application of Bioactive Compounds)

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18 pages, 2200 KiB

Open AccessArticle

Improved Expression of Aggregation-Prone Tau Proteins Using a Spidroin-Derived Solubility Tag

by Kevin Muwonge, Bedri Yaman, Attila Mészáros, Giorgio Russo, Alexander Volkov and Peter Tompa

Separations 2024, 11(7), 198; https://doi.org/10.3390/separations11070198 - 25 Jun 2024

Viewed by 1595

Abstract

Tauopathies, a group of neurodegenerative disorders, are characterized by the abnormal aggregation of microtubule-associated Tau proteins in neurons and glial cells. The process of Tau proteins transitioning from soluble, intrinsically disordered monomers to disease-associated aggregates is still unclear. Investigating these molecular mechanisms requires [...] Read more.

Tauopathies, a group of neurodegenerative disorders, are characterized by the abnormal aggregation of microtubule-associated Tau proteins in neurons and glial cells. The process of Tau proteins transitioning from soluble, intrinsically disordered monomers to disease-associated aggregates is still unclear. Investigating these molecular mechanisms requires the reconstitution of such processes in cellular and in vitro models using recombinant proteins at high purity and yield. However, the production of phase-separating or aggregation-prone recombinant proteins like Tau’s hydrophobic-rich domains or disease mutation-carrying variants on a large scale is highly challenging due to their limited solubility. To overcome this challenge, we have developed an improved strategy for expressing and purifying recombinant Tau proteins using the major ampullate spidroin-derived solubility tag (MaSp-NT*). This approach involves using NT* as a fusion tag to enhance the solubility and stability of expressed proteins by forming micelle-like particles within the cytosol of E. coli cells. We found that fusion with the NT* tag significantly increased the solubility and yield of highly hydrophobic and/or aggregation-prone Tau constructs. Our purification method for NT* fusion proteins yielded up to twenty-fold higher amounts than proteins purified using our novel tandem-tag (6xHis-SUMO-Tau-Heparin) purification system. This enhanced expression and yield were demonstrated with full-length Tau (hT40/Tau441), its particularly aggregation-prone repeat domain (Tau-MTBR), and Frontotemporal dementia (FTD)-associated mutant (Tau-P301L). These advancements offer promising avenues for the production of large quantities of Tau proteins suitable for in vitro experimental techniques such as nuclear magnetic resonance (NMR) spectroscopy without the need for a boiling step, bringing us closer to effective treatments for tauopathies. Full article

(This article belongs to the Special Issue Peptide Synthesis, Separation and Purification)

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14 pages, 1509 KiB

Open AccessArticle

Simultaneous LC-MS/MS Method for the Quantitation of Probenecid, Albendazole, and Its Metabolites in Human Plasma and Dried Blood Spots

by Mamunur Rashid, Yashpal S. Chhonker, Sandeep K. Singh and Daryl J. Murry

Separations 2024, 11(7), 197; https://doi.org/10.3390/separations11070197 - 25 Jun 2024

Viewed by 1245

Abstract

Millions of individuals throughout the world suffer from lymphatic filariasis (LF), which is a morbid disease caused by Wuchereria bancrofti, Brugia malayi, and Brugia timori. These infections belong to tissue-invading nematodes and are one of the major neglected tropical diseases [...] Read more.

Millions of individuals throughout the world suffer from lymphatic filariasis (LF), which is a morbid disease caused by Wuchereria bancrofti, Brugia malayi, and Brugia timori. These infections belong to tissue-invading nematodes and are one of the major neglected tropical diseases that often result in permanent and enduring disability among individuals in endemic regions. Due to combination therapy, LF eradication has drastically decreased infections globally. The development of blood micro-sampling techniques allowing precise quantitation of drugs in blood would facilitate pharmacokinetic (PK) studies in remote populations. Therefore, an LC-MS/MS bioanalytical method was utilized to analyze albendazole (ABZ), albendazole sulfone (ABZ-ON), albendazole sulfoxide (ABZ-OX), and probenecid (PR) in plasma and dried blood spots. Solid-phase extraction was utilized to extract the analyte from both plasma and blood-spiked DBS. Analytes of interest were eluted with a gradient mobile system using 0.05% formic acid in water (A) and 0.05% formic acid in methanol (B) and separated using a reversed-phase Acquity ^®BEH C18 UPLC column (100 × 2.1 mm, 1.7 µm). Precision and accuracy at each QC level were within the acceptable limit, i.e., ±15% for all analytes in both the matrices. Tests for stability under laboratory and storage conditions indicated that no notable changes were observed for plasma and DBS. The LC-MS/MS method demonstrated its capability to consistently identify all target analytes (ABZ, ABZ-ON, ABZ-OX, and PR) at low concentrations, even at the small specimen volumes obtained from DBS cards. This confirms the efficacy and durability of DBS cards as a micro-sampling technique. Moreover, it enhances collection efforts for therapeutic drug monitoring in remote locations for patients infected with lymphatic filariasis. Full article

(This article belongs to the Special Issue Advances in Chemical Fingerprint Assessment and Analytical Isolation of Natural Products and Pharmaceuticals)

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21 pages, 5071 KiB

Open AccessReview

Summary of Pretreatment of Waste Lithium-Ion Batteries and Recycling of Valuable Metal Materials: A Review

by Linye Li, Yuzhang Li and Guoquan Zhang

Separations 2024, 11(7), 196; https://doi.org/10.3390/separations11070196 - 25 Jun 2024

Viewed by 1479

Abstract

The recycling of used lithium-ion batteries has become a growing concern. As a large number of rare metal elements are present in waste lithium-ion batteries, recycling them can significantly improve resource utilization and reduce the material cost of battery production. The process of [...] Read more.

The recycling of used lithium-ion batteries has become a growing concern. As a large number of rare metal elements are present in waste lithium-ion batteries, recycling them can significantly improve resource utilization and reduce the material cost of battery production. The process of recycling used lithium-ion batteries involves three main technology parts: pretreatment, material recovery, and cathode material recycling. Pretreatment includes discharge treatment, uniform crushing, and removing impurities. Material-recovery technology mainly involves traditional pyrometallurgical and hydrometallurgical technologies, as well as the developing biometallurgy technology. Analysis of existing data shows that pretreatment technology is crucial for the recycling of used lithium-ion batteries. Hydrometallurgical technology and pyro-hydrometallurgical technology are expected to be the most suitable industrialization technology paths in the future, with biometallurgical technology and direct recycling technology providing a low-pollution development direction. This article summarizes the different pretreatment techniques and valuable metal-recovery pathways. The advantages and disadvantages of each method were evaluated. The economic costs, environmental benefits, and degree of industrialization of each method were assessed. The possible development directions of various methods are summarized to provide reference for future research. Full article

(This article belongs to the Section Analysis of Energies)

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30 pages, 2012 KiB

Open AccessReview

Puerariae lobatae Radix: Progress in Extraction, Separation Methods and Pharmacological Activities Research

by Erjian Gao, Wei Wang, Yuanyuan Huang, Zhijie Luo, Bangzheng Chen, Siqiu Xiao and Dewen Li

Separations 2024, 11(7), 195; https://doi.org/10.3390/separations11070195 - 24 Jun 2024

Viewed by 1188

Abstract

Kudzu root (Puerariae lobatae Radix) is the tuberous root of Pueraria lobata, family Leguminosae. Kudzu root contains a variety of beneficial active ingredients such as puerarin, daidzin, daidzein, genistenin, 3′-hydroxy puerarin, β-sitosterol, stigmasterol, arachidic acid, and so on. Modern medical research [...] Read more.

Kudzu root (Puerariae lobatae Radix) is the tuberous root of Pueraria lobata, family Leguminosae. Kudzu root contains a variety of beneficial active ingredients such as puerarin, daidzin, daidzein, genistenin, 3′-hydroxy puerarin, β-sitosterol, stigmasterol, arachidic acid, and so on. Modern medical research shows that active ingredients in kudzu root are widely used clinically as raw materials for the treatment of hyperglycemia, non-alcoholic fatty liver disease, myocardial infarction, alcohol addiction, oxidative stress, inflammatory response, and retinal blockage due to their various pharmacological effects such as improving cardiovascular circulation, lowering blood lipids, lowering blood pressure, lowering blood sugar, being antipyretic, being estrogen-like, and relieving alcohol. China has rich resources of kudzu root, and active ingredients are usually extracted before it is made into a preparation, so whether the extraction and separation process is reasonable will directly affect the ease of preparation and the efficacy of the treatment. This paper reviews the process methods for the extraction and separation of active ingredients in kudzu root and its common pharmacological activities. The aim is to provide some references for readers to compare the advantages and disadvantages of various extraction and separation methods as well as understand the active ingredients and pharmacological activities of kudzu root. Full article

(This article belongs to the Special Issue Advances in Chemical Fingerprint Assessment and Analytical Isolation of Natural Products and Pharmaceuticals)

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15 pages, 2119 KiB

Open AccessArticle

Rapid Discovery of Antimicrobial and Antimalarial Agents from Natural Product Fragments

by Jianying Han, Xueting Liu, Lixin Zhang, Wesley C. Van Voorhis, Ronald J. Quinn and Miaomiao Liu

Separations 2024, 11(7), 194; https://doi.org/10.3390/separations11070194 - 23 Jun 2024

Viewed by 779

Abstract

Fragment-based drug discovery (FBDD) focuses on small compounds, known as fragments, typically with a molecular weight of less than 300 Da. This study highlights the benefits of employing a pure natural product library for FBDD, contrasting with the predominant use of synthetic libraries. [...] Read more.

Fragment-based drug discovery (FBDD) focuses on small compounds, known as fragments, typically with a molecular weight of less than 300 Da. This study highlights the benefits of employing a pure natural product library for FBDD, contrasting with the predominant use of synthetic libraries. Practical methods for rapidly constructing such libraries from crude extracts were demonstrated across various plant and microbial samples. Twenty-nine (29) natural product fragments, including a new compound (20), were identified. Antimicrobial activities were assessed for a subset of the isolated compounds, revealing potent fragments (MICs 4–8 μg/mL) against Mycobacterium bovis bacille Calmette-Guérin (BCG), Staphylococcus aureus (SA), and methicillin-resistant S. aureus (MRSA). Furthermore, a native mass spectrometry technique was introduced to rapidly identify non-competitive fragments against malarial proteins. As a result, two pairs of non-competitive fragments, lepiotin C (31) and 7-amino deacetoxy cephalosporanic acid (32) binding to dynein light chain 1, methyl gallate (33) and β-santanin (34) binding to dUTPase, were identified, serving as promising starting points for developing potent malarial protein inhibitors. Full article

(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)

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11 pages, 1398 KiB

Open AccessEditor’s ChoiceArticle

A Novel Solvent Microextraction Lab-in-Syringe System Coupled with Atomic Absorption Spectrometry for Thallium Determination in Water Samples

by Arina Skok, Natalia Manousi, Yaroslav Bazel, Andriy Vishnikin and Aristidis Anthemidis

Separations 2024, 11(7), 193; https://doi.org/10.3390/separations11070193 - 21 Jun 2024

Viewed by 837

Abstract

Thallium is an accumulative highly toxic metal, that can be present in environmental samples due to industrial pollution and is dangerous for living organisms. Thus, its determination at trace levels is necessary. The lab-in-syringe (LIS) is considered to be a simple, functional, and [...] Read more.

Thallium is an accumulative highly toxic metal, that can be present in environmental samples due to industrial pollution and is dangerous for living organisms. Thus, its determination at trace levels is necessary. The lab-in-syringe (LIS) is considered to be a simple, functional, and versatile, technique that combines operational concepts and flow and sequential injection analysis. In this study, a liquid-phase microextraction LIS system was developed as a front-end to flame atomic absorption spectrometry (FAAS) for the determination of thallium in water samples. The proposed approach is based on the formation of Tl(III) ammonium–pyrrolidine–dithiocarbamate complex followed by its extraction using di-isobutyl-ketone. These procedures take place within the syringe barrel of the LIS system. The limit of detection of the developed method was 2.1 µg L⁻¹ with a linear range from 7.0 to 400 µg L⁻¹. The relative standard deviation (RSD) was 3.9% (at 50.0 µg L⁻¹ Tl(I)), demonstrating good precision. Moreover, good method accuracy was obtained since the relative recovery values were within the range of 93.4–101.2%. Finally, reliable method applicability and green merits were demonstrated using the blue applicability grade index and green analytical procedure index, respectively. The proposed method was used for the analysis of environmental water samples. Full article

(This article belongs to the Section Purification Technology)

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13 pages, 4485 KiB

Open AccessArticle

Study on the Efficiency of Fine Particle Removal in a Single-Tower Dual-Cycle Desulfurization Process Utilizing Heterogeneous Condensation

by Rui Zhang, Zulpher Ahmad Mnipela, Linjun Yang and Xiaodong Si

Separations 2024, 11(7), 192; https://doi.org/10.3390/separations11070192 - 21 Jun 2024

Viewed by 726

Abstract

This study investigated a new method for controlling the emission of fine particles through heterogeneous condensation. Specifically, the research focuses on the application of single-tower double-cycle desulfurization technology in the wet flue gas desulfurization process. The establishment of a supersaturation environment necessary for [...] Read more.

This study investigated a new method for controlling the emission of fine particles through heterogeneous condensation. Specifically, the research focuses on the application of single-tower double-cycle desulfurization technology in the wet flue gas desulfurization process. The establishment of a supersaturation environment necessary for heterogeneous condensation was achieved by reducing the temperature of desulfurization slurry in the oxidation zone. Numerical simulations were used to study the distribution of the supersaturation degree and fluid dynamics characteristics in the desulfurization tower after the cooling of desulfurization slurry. Furthermore, the impact of single-tower double-cycle technology on the removal efficiency of fine particles was examined. The results of the numerical simulations indicate that cooling the desulfurization slurry in the absorption zone could establish a supersaturated vapor environment, with the supersaturation degree and region increasing as the slurry temperature decreases. Under typical operating conditions, a temperature drop of approximately 8~10 °C was found to be most suitable for the desulfurization slurry. Moreover, lowering the temperature of the desulfurization slurry in the absorption zone increases the supersaturation degree from 0.93 to 1.85. Additionally, the use of single-tower double-cycle desulfurization technology is shown to significantly enhance the removal efficiency of fine particles, particularly those within the particle size range of 0.1~1 μm. Ultimately, this method could increase the removal efficiency of fine particles from 39.9% to 57.9%. Full article

(This article belongs to the Collection Feature Paper Collection in Section 'Purification Technology')

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