Separations

26 pages, 6477 KiB

Open AccessArticle

Multiprotein Inhibitory Effect of Dietary Polyphenol Rutin from Whole Green Jackfruit Flour Targeting Different Stages of Diabetes Mellitus: Defining a Bio-Computational Stratagem

by Tejaswini Maradesha, Shashank M. Patil, Bhaskar Phanindra, Raghu Ram Achar, Ekaterina Silina, Victor Stupin and Ramith Ramu

Separations 2022, 9(9), 262; https://doi.org/10.3390/separations9090262 - 19 Sep 2022

Cited by 13 | Viewed by 3581

Abstract

The anti-diabetic potential of whole unripe jackfruit (peel with pulp, flake, and seed) was investigated using inhibitory assays for α-glucosidase, α-amylase, aldose reductase, and glycation at multiple stages. Using activity-guided repeated fractionation on a silica gel column chromatography, dietary flavonoid rutin with potent [...] Read more.

The anti-diabetic potential of whole unripe jackfruit (peel with pulp, flake, and seed) was investigated using inhibitory assays for α-glucosidase, α-amylase, aldose reductase, and glycation at multiple stages. Using activity-guided repeated fractionation on a silica gel column chromatography, dietary flavonoid rutin with potent antihyperglycemic activity was extracted from the methanol extract of whole jackfruit flour (MJ). Rutin was found to inhibit both α-glucosidase (IC₅₀: 7.86 µg/mL) and α-amylase (IC₅₀: 22.00 µg/mL) in a competitive manner of inhibition with low Ki values. In addition, in vitro glycation experiments revealed that rutin prevented each stage of protein glycation as well as the production of intermediate molecules. Furthermore, rutin significantly inhibited aldose reductase (IC₅₀: 2.75 µg/mL) in a non-competitive manner. During in silico studies, molecular docking and molecular dynamics simulation studies have suggested that rutin has a high binding affinity for the enzymes studied, which could explain its inhibitory effects. Rutin interacted with the key residues of the target enzymes’ inhibitor binding sites. Compared to the controls used, rutin had a higher binding efficiency as well as stability in the inhibitor binding pocket of the target enzymes. According to our findings, the presence of rutin is more likely to be associated with the potential of MJ in antihyperglycemic activity via inhibition of α-glucosidase and in anti-diabetic action via inhibition of the polyol pathway and protein glycation. The bio-computational study indicates rutin as a potential lead inhibitor of all the target enzymes used and could be used as an effective anti-diabetic drug in the near future. Full article

(This article belongs to the Topic Discovery of Bioactive Compounds from Natural Organisms and Their Molecular Mechanisms against Diseases)

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15 pages, 2054 KiB

Open AccessArticle

Research on the Removal of Levamisole Residues in Bovine, Ovine, Caprine, Porcine and Poultry Tissues

by Viviana Carmen Ciucă, Carmen Otilia Rusănescu and Victor Viorel Safta

Separations 2022, 9(9), 261; https://doi.org/10.3390/separations9090261 - 14 Sep 2022

Cited by 4 | Viewed by 2507

Abstract

In this paper, we set the waiting time for the elimination of levamisole residues at a safe level from tissues (muscles and organs) from animals treated with levamisole 10%—oral solution. We studied the depletion of levamisole residues by high performance liquid chromatography with [...] Read more.

In this paper, we set the waiting time for the elimination of levamisole residues at a safe level from tissues (muscles and organs) from animals treated with levamisole 10%—oral solution. We studied the depletion of levamisole residues by high performance liquid chromatography with a mass spectrometer (limit of quantification 2 μg/kg) in the tissues of bovine, ovine, caprine, porcine and poultry (chickens and pigeons) after administration of levamisole (10 mg levamisole/kg body weight for cattle, sheep, goats, pigs and 20 mg levamisole/kg body weight for birds). We found that in cattle, sheep and goats at 7 days after treatment, the residues of levamisole in the liver and at 14 days and in the other tissues were below the established limit value. In pigs at 7 days, residues from all tissues were below the set limit value. Residue depletion in chickens treated with levamisole was rapid, such that 3 days after treatment, the residues in all tissues were below the set limit. Residue depletion was slower in turkeys than in chickens. Full article

(This article belongs to the Special Issue Applications of Chromatography Technology)

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19 pages, 6821 KiB

Open AccessArticle

Exploring the Antioxidant and Bioinsecticidal Activity of Spontaneous Flora Vegetal Extracts for Plant Protection and Prevention of Soil Contamination

by Gabriel Mihăiță Daraban, Lăcrămioara Rusu, Rodica Mihaela Dinica, Mihaela Roşca, Marinela Badeanu, Maria Daniela Ionica Mihaila and Daniela Suteu

Separations 2022, 9(9), 260; https://doi.org/10.3390/separations9090260 - 13 Sep 2022

Cited by 2 | Viewed by 2283

Abstract

The purpose of this article was to evaluate the application of different plant extracts with bioinsecticidal action and antioxidant activity for plants and soil protection, by substitution of the application of synthetically formulated pesticides with eco-friendly compounds. In this framework, this research focused [...] Read more.

The purpose of this article was to evaluate the application of different plant extracts with bioinsecticidal action and antioxidant activity for plants and soil protection, by substitution of the application of synthetically formulated pesticides with eco-friendly compounds. In this framework, this research focused on the utilization of plant extracts from the spontaneous flora of Moldova (Romania) as bioinsecticides for the control of field pests of the species Leptinotarsa decemlineata and their antioxidant activity. Plant extracts of oregano (Origanum vulgare), yarrow (Achillea millefolium), wormwood (Artemisia absinthium), and cowslip (Primula veris) were assessed for their antioxidant activity by the microplate spectrophotometric-based method (for polyphenols and flavonoids content and for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenger activity) and were characterized by FTIR spectroscopy spectra. To evaluate the bioinsecticidal properties of the plant extracts, the mortality (%) and neuroleptic manifestations appearing in the middle of the monitoring period for larvae and adults of the Leptinotarsa decemlineata species were identified. Mortality (%) was statistically analyzed using a one-way analysis of variance (ANOVA) and the resulting experimental results were compared with the LSD-Fisher’s test (p < 0.05). The highest mortality (%) was observed after 24 h of treatment with extracts of Origanum vulgare at 100% concentration, while the maximum effect was recorded after 48 h for Origanum vulgare at 60% and 100% concentrations. Full article

(This article belongs to the Special Issue Removal of Emerging Pollutants and Environmental Analysis)

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11 pages, 1702 KiB

Open AccessArticle

Recovery of Valuable Metals from Cathode—Anode Mixed Materials of Spent Lithium-Ion Batteries Using Organic Acids

by Kun Wang, Guoquan Zhang and Mingzhi Luo

Separations 2022, 9(9), 259; https://doi.org/10.3390/separations9090259 - 13 Sep 2022

Cited by 6 | Viewed by 2550

Abstract

Spent lithium-ion batteries (LIBs) contain a large number of valuable metals and will be an important strategic resource in the future. Therefore, recycling is extremely important. In this work, acetic acid and hydrogen peroxide were used as leaching agents to recover valuable metals [...] Read more.

Spent lithium-ion batteries (LIBs) contain a large number of valuable metals and will be an important strategic resource in the future. Therefore, recycling is extremely important. In this work, acetic acid and hydrogen peroxide were used as leaching agents to recover valuable metals (lithium, cobalt, nickel, manganese, and aluminum) from cathode and anode materials (LiCoO₂, LiAl_0.2Co_0.8O₂, and C) of spent LIBs. The leaching solution and leaching residue were analyzed by inductive plasma optical emission spectrometry (ICP-OES), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The optimum experimental conditions were obtained by changing the concentration of acetic acid, solid–liquid ratio, reaction temperature, time, and the concentration of hydrogen peroxide reducing agent. Under the experimental conditions of 2 M acetic acid, 4.0 vol.% H₂O₂, 20 g/L, and 70 °C for 40 min, the leaching rates of lithium, cobalt, nickel, manganese, and aluminum reached 98.56%, 94.61%, 96.39%, 97.97%, and 94.7%, respectively. This hydrometallurgical process is simple and environmentally friendly and maximizes the recovery of valuable metals from spent LIBs. Full article

(This article belongs to the Special Issue Efficient and Green Recovery of Metal Minerals)

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21 pages, 6589 KiB

Open AccessArticle

Synthesis, Characterization, and Performance Evaluation of Hybrid Waste Sludge Biochar for COD and Color Removal from Agro-Industrial Effluent

by Ahmad Hussaini Jagaba, Shamsul Rahman Mohamed Kutty, Sule Abubakar, Abdullahi Haruna Birniwa, Ibrahim Mohammed Lawal, Ibrahim Umaru, Abdullahi Kilaco Usman, Nura Shehu Aliyu Yaro, Nabil Al-Zaqri, Basheer M. Al-Maswari, Mohamad Nasir Mohamad Ibrahim and Fida Hussain

Separations 2022, 9(9), 258; https://doi.org/10.3390/separations9090258 - 13 Sep 2022

Cited by 29 | Viewed by 2836

Abstract

Agro-waste management processes are evolving through the development of novel experimental approaches to understand the mechanisms in reducing their pollution levels efficiently and economically from industrial effluents. Agro-industrial effluent (AIE) from biorefineries that contain high concentrations of COD and color are discharged into [...] Read more.

Agro-waste management processes are evolving through the development of novel experimental approaches to understand the mechanisms in reducing their pollution levels efficiently and economically from industrial effluents. Agro-industrial effluent (AIE) from biorefineries that contain high concentrations of COD and color are discharged into the ecosystem. Thus, the AIE from these biorefineries requires treatment prior to discharge. Therefore, the effectiveness of a continuous flow bioreactor system (CFBS) in the treatment of AIE using hybrid waste sludge biochar (HWSB) was investigated. The use of a bioreactor with hydraulic retention time (HRT) of 1–3 days and AIE concentrations of 10–50% was used in experiments based on a statistical design. AIE concentration and HRT were optimized using response surface methodology (RSM) as the process variables. The performance of CFBS was analyzed in terms of COD and color removal. Findings indicated 76.52% and 66.97% reduction in COD and color, respectively. During biokinetic studies, the modified Stover models were found to be perfectly suited for the observed measurements with R² values 0.9741 attained for COD. Maximum contaminants elimination was attained at 30% AIE and 2-day HRT. Thus, this study proves that the HWSB made from biomass waste can potentially help preserve nonrenewable resources and promote zero-waste attainment and principles of circular economy. Full article

(This article belongs to the Special Issue Separation Processes for Effective Removal of Emerging Contaminants from Water and Wastewater)

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14 pages, 1567 KiB

Open AccessArticle

Influence of Geographical Location of Spirulina (Arthrospira platensis) on the Recovery of Bioactive Compounds Assisted by Pulsed Electric Fields

by Francesc Ramon-Mascarell, Francisco J. Martí-Quijal, Juan Manuel Castagnini, Yuthana Phimolsiripol, Warintorn Ruksiriwanich, Muhammad Shahid Riaz Rajoka, Hafiza Mahreen Mehwish and Francisco J. Barba

Separations 2022, 9(9), 257; https://doi.org/10.3390/separations9090257 - 13 Sep 2022

Cited by 3 | Viewed by 2269

Abstract

Spirulina (Arthrospira platensis) has been consumed by humans since ancient times. It is rich in high added-value compounds such as chlorophylls, carotenoids and polyphenols. Pulsed electric fields (PEF) is an innovative non-thermal technique that improves the extraction of bioactive compounds from [...] Read more.

Spirulina (Arthrospira platensis) has been consumed by humans since ancient times. It is rich in high added-value compounds such as chlorophylls, carotenoids and polyphenols. Pulsed electric fields (PEF) is an innovative non-thermal technique that improves the extraction of bioactive compounds from diverse sources. PEF pre-treatment (3 kV/cm, 100 kJ/kg) combined with supplementary extraction with binary solvents at different times was evaluated to obtain the optimal conditions for extraction. In addition, the results obtained were compared with conventional treatment (without PEF pre-treatment and constant shaking) and different strains of Spirulina from diverse geographical locations. The optimal extraction conditions for recovering the bioactive compounds were obtained after applying PEF treatment combined with the binary mixture EtOH/H₂O for 180 min. The recovery of total phenolic content (TPC) (19.76 ± 0.50 mg/g DM (dry matter) and carotenoids (0.50 ± 0.01 mg/g DM) was more efficient in the Spirulina from Spain. On the other hand, there was a higher recovery of chlorophylls in the Spirulina from China. The highest extraction of total antioxidant compounds was in Spirulina from Costa Rica. These results show that PEF, solvents and the condition of growing affect the extraction of antioxidant bioactive compounds from Spirulina. The combination of PEF and EtOH/H₂O is a promising technology due to its environmental sustainability. Full article

(This article belongs to the Special Issue Methods for the Chemical Analysis and Separation of Compounds in Plants)

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26 pages, 20238 KiB

Open AccessReview

Exploring the Biosorption of Methylene Blue Dye onto Agricultural Products: A Critical Review

by Manish Kumar Sah, Khaled Edbey, Ashraf EL-Hashani, Sanad Almshety, Luisetto Mauro, Taghrid S. Alomar, Najla AlMasoud and Ajaya Bhattarai

Separations 2022, 9(9), 256; https://doi.org/10.3390/separations9090256 - 13 Sep 2022

Cited by 21 | Viewed by 4186

Abstract

Due to their higher specific area and, in most cases, higher adsorption capacity, nanomaterials are noteworthy and attractive adsorbents. Agricultural products that are locally available are the best option for removing methylene blue (MB) dye from aqueous solutions. Because it is self-anionic, FT-IR [...] Read more.

Due to their higher specific area and, in most cases, higher adsorption capacity, nanomaterials are noteworthy and attractive adsorbents. Agricultural products that are locally available are the best option for removing methylene blue (MB) dye from aqueous solutions. Because it is self-anionic, FT-IR and SEM investigations of biosorption have confirmed the role of the functional group and its contribution to the formation of pores that bind cationic dye. It is endothermic if the adsorption of MB by an adsorbent is high as the temperature increases; on the other hand, exothermic if it is high as the temperature decreases. A basic medium facilitates adsorption with respect to pH; adsorption is proportional to the initial concentration at a certain level before equilibrium; after equilibrium, adsorption decreases. A pseudo-second-order model applies for certain agricultural products. As per plotted graph for the solid-phase concentration against the liquid-phase concentration, the Langmuir adsorption isotherm model is favored; this model describes a situation in which a number of molecules are adsorbed by an equal number of available surface sites, and there is no interaction between adsorbate molecules once all sites are occupied. In contrast, the Freundlich model depicts non-ideal multi-layer sorption onto heterogeneous surfaces via numerical analysis; with a value of n = 1, the result is a linear isotherm. If the value of n < 1 or n > 1, then it is chemical or physical adsorption, respectively. Based on an EDX analysis, relevant elements are confirmed. BET analysis confirms the surface area. Nanoproducts categorized as agricultural products exhibit the aforementioned tendency. Even though nanoparticles show positive outcomes in terms of higher adsorption, a high specific area for the targeted pollutant is needed in real-world applications. In the relevant sections herein, the behavior of thermodynamic parameters, such as enthalpy, entropy, and Gibbs free energy, are examined. There is some question as to which form of agricultural waste is the most effective adsorption medium. There is no direct answer because every form of agricultural waste has its own distinct chemical and physical characteristics, such as porosity, surface area, and strength. Full article

(This article belongs to the Special Issue Micro/Nano-Material-Assisted Sample Pre-treatment and Separation for Chemical and Biochemical Analysis)

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11 pages, 595 KiB

Open AccessArticle

Recovery of Bioactive Extracts from Olive Leaves Using Conventional and Microwave-Assisted Extraction with Classical and Deep Eutectic Solvents

by Eleni Boli, Nikos Prinos, Vasiliki Louli, Georgia Pappa, Haralambos Stamatis, Kostis Magoulas and Epaminondas Voutsas

Separations 2022, 9(9), 255; https://doi.org/10.3390/separations9090255 - 9 Sep 2022

Cited by 20 | Viewed by 3388

Abstract

The recovery of phenolic compounds from olive leaves (Olea europaea L.) has received special attention due to their significant potential for applications in food, nutraceuticals, cosmetics, and pharmaceuticals. In this work, the extraction of the phenolic compounds from olive leaves was examined [...] Read more.

The recovery of phenolic compounds from olive leaves (Olea europaea L.) has received special attention due to their significant potential for applications in food, nutraceuticals, cosmetics, and pharmaceuticals. In this work, the extraction of the phenolic compounds from olive leaves was examined by means of conventional extraction and microwave-assisted extraction (MAE) using nontoxic common solvents such as ethanol and water as well as using promising environmentally friendly, Deep Eutectic Solvents (DESs) and their mixtures with ethanol or water. The effects of the various parameters that likely govern the extractability of the bioactive compounds of olive leaves (OL), such as the solvent type, temperature, and biomass to solvent mass ratio, were studied and evaluated with regard to the oleuropein and hydroxytyrosol content, antioxidant activity, and total phenolic content of the extracts. The study also explores the effects of the microwave-assisted extraction parameters, namely irradiation power and time, on the total phenolic content and antioxidant activity of the extracts. The findings of this work suggest that among the solvents studied, the solvent mixture consisting of the DES choline chloride:acetic acid with a molar ratio of 1:2 and ethanol (80:20 w/w) is highly effective in recovering extracts rich in phenolic compounds and with significant antioxidant activity. Moreover, it is demonstrated that the MAE method allows for the recovery of bioactive compounds in a very short processing time. Full article

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10 pages, 3597 KiB

Open AccessArticle

Wound Healing Potential of Commiphora gileadensis Stems Essential Oil and Chloroform Extract

by Hassan N. Althurwi, Mohammad Ayman A. Salkini, Gamal A. Soliman, Mohd Nazam Ansari, Elmutasim O. Ibnouf and Maged S. Abdel-Kader

Separations 2022, 9(9), 254; https://doi.org/10.3390/separations9090254 - 8 Sep 2022

Cited by 5 | Viewed by 2564

Abstract

Essential oils (EOs) prepared from the fresh and dried stems of Commiphora gileadensis were compared qualitatively and quantitatively. Although the components were closely similar, the amount of oil decreased from 2.23 to 1.77% upon drying. Both samples showed equal potencies in the antimicrobial [...] Read more.

Essential oils (EOs) prepared from the fresh and dried stems of Commiphora gileadensis were compared qualitatively and quantitatively. Although the components were closely similar, the amount of oil decreased from 2.23 to 1.77% upon drying. Both samples showed equal potencies in the antimicrobial testing. The chloroform extract (CE) of the fresh stems with reported antimicrobial activity was compared with the EO sample of the fresh stems for wound healing potential. For the wound healing assay, 11 mm-diameter full-thickness skin excision wounds were made on the backs of four groups of rats (n = 6). The negative control group I was treated with the cream base. Group II was treated with 2% Fucidin cream, which served as a reference, and groups III and IV were treated with 1% EO- and 3% CE-containing creams, respectively. Treatments were applied topically one time daily. The wound healing potential was evaluated by recording the wound contraction percentages, epithelialization period, and histopathological changes of wounds. The topical application of CE significantly promoted the healing of wounds in rats. The effectiveness was demonstrated through the speed of wound contraction and the shortening of the epithelialization period in an animal treated with CE cream when compared to the NC group. Histopathological studies of the CE cream-treated group also expressed the effectiveness of CE in improving the wound healing process. These findings suggested that CE cream can enhance the process of wound healing in rats. Full article

(This article belongs to the Special Issue Extraction and Analysis of Plant Active Ingredients)

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4 pages, 204 KiB

Open AccessEditorial

Novel Polymeric Membranes Preparation and Membrane Process

by Wenzhong Ma, Yakai Lin and Yuanhui Tang

Separations 2022, 9(9), 253; https://doi.org/10.3390/separations9090253 - 7 Sep 2022

Cited by 1 | Viewed by 1825

Abstract

Polymer-based membranes have advanced or novel functions in the various membrane separation processes for liquid and gaseous mixtures, such as gas separation, pervaporation (PV), reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), microfiltration (MF), and in other critical applications of membranes such as water [...] Read more.

Polymer-based membranes have advanced or novel functions in the various membrane separation processes for liquid and gaseous mixtures, such as gas separation, pervaporation (PV), reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), microfiltration (MF), and in other critical applications of membranes such as water purification, solvent concentration, and recovery [...] Full article

(This article belongs to the Special Issue Advances in Novel Polymeric Membranes and Membrane Process)

13 pages, 1793 KiB

Open AccessArticle

High-Purity Corundum as Support for Affinity Extractions from Complex Samples

by Jule L. Völzke, Parya Hodjat Shamami, Kornelia Gawlitza, Ines Feldmann, Annett Zimathies, Klas Meyer and Michael G. Weller

Separations 2022, 9(9), 252; https://doi.org/10.3390/separations9090252 - 7 Sep 2022

Cited by 1 | Viewed by 2440

Abstract

Nonporous corundum powder, known as an abrasive material in the industry, was functionalized covalently with protein binders to isolate and enrich specific proteins from complex matrices. The materials based on corundum were characterized by TEM, ESEM, BET, DLS, EDS, and zeta potential measurements. [...] Read more.

Nonporous corundum powder, known as an abrasive material in the industry, was functionalized covalently with protein binders to isolate and enrich specific proteins from complex matrices. The materials based on corundum were characterized by TEM, ESEM, BET, DLS, EDS, and zeta potential measurements. The strong Al-O-P bonds between the corundum surface and amino phosphonic acids were used to introduce functional groups for further conjugations. The common crosslinker glutaraldehyde was compared with a hyperbranched polyglycerol (PG) of around 10 kDa. The latter was oxidized with periodate to generate aldehyde groups that can covalently react with the amines of the surface and the amino groups from the protein via a reductive amination process. The amount of bound protein was quantified via aromatic amino acid analysis (AAAA). This work shows that oxidized polyglycerol can be used as an alternative to glutaraldehyde. With polyglycerol, more of the model protein bovine serum albumin (BSA) could be attached to the surface under the same conditions, and lower non-specific binding (NSB) was observed. As a proof of concept, IgG was extracted with protein A from crude human plasma. The purity of the product was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). A binding capacity of 1.8 mg IgG per gram of corundum powder was achieved. The advantages of corundum include the very low price, extremely high physical and chemical stability, pressure resistance, favorable binding kinetics, convenient handling, and flexible application. Full article

(This article belongs to the Special Issue Advances in Separation Engineering)

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13 pages, 1486 KiB

Open AccessArticle

Determination of the Loading Capacity and Recovery of Extracellular Vesicles Derived from Human Embryonic Kidney Cells and Urine Matrices on Capillary-Channeled Polymer (C-CP) Fiber Columns

by Lacey S. Billotto, Kaylan K. Jackson and R. Kenneth Marcus

Separations 2022, 9(9), 251; https://doi.org/10.3390/separations9090251 - 7 Sep 2022

Cited by 3 | Viewed by 1838

Abstract

Extracellular vesicles (EVs) are 50–1000 nm membranous vesicles secreted from all cells that play important roles in many biological processes. Exosomes, a smaller-sized subset of EVs, have become of increasing interest in fundamental biochemistry and clinical fields due to their rich biological cargos [...] Read more.

Extracellular vesicles (EVs) are 50–1000 nm membranous vesicles secreted from all cells that play important roles in many biological processes. Exosomes, a smaller-sized subset of EVs, have become of increasing interest in fundamental biochemistry and clinical fields due to their rich biological cargos and their roles in processes such as cell-signaling, maintaining homeostasis, and regulating cellular functions. To be implemented effectively in fundamental biochemistry and clinical diagnostics fields of study, and for their proposed use as vectors in gene therapies, there is a need for new methods for the isolation of large concentrations of high-purity exosomes from complex matrices in a timely manner. To address current limitations regarding recovery and purity, described here is a frontal throughput and recovery analysis of exosomes derived from human embryonic kidney (HEK) cell cultures and human urine specimens using capillary-channeled polymer (C-CP) fiber stationary phases via high performance liquid chromatography (HPLC). Using the C-CP fiber HPLC method for EV isolations, the challenge of recovering purified EVs from small sample volumes imparted by the traditional techniques was overcome while introducing significant benefits in processing, affordability (~5 $ per column), loading (~10¹² particles), and recovery (10¹¹–10¹² particles) from whole specimens without further processing requirements. Full article

(This article belongs to the Special Issue Feature Papers in Separations from Editorial Board Members)

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7 pages, 1090 KiB

Open AccessArticle

False Positive Results of Phosphatidylethanol (PEth) Quantitation in Dried Blood Spots (DBS): The Influence of Alcohol Vapors

by Anton Bashilov, Sergey Osipenko, Karolina Ikonnikova, Oxana Kovaleva, Boris Izotov, Evgeny Nikolaev and Yury Kostyukevich

Separations 2022, 9(9), 250; https://doi.org/10.3390/separations9090250 - 7 Sep 2022

Cited by 1 | Viewed by 9509

Abstract

The role of phosphatidylethanol (PEth) as an alcohol consumption marker is increasing in clinical and forensic medicine. During the COVID-19 pandemic, the role of hygiene increased, and it became common practice to use disinfectants almost everywhere. This paper highlights a possible source of [...] Read more.

The role of phosphatidylethanol (PEth) as an alcohol consumption marker is increasing in clinical and forensic medicine. During the COVID-19 pandemic, the role of hygiene increased, and it became common practice to use disinfectants almost everywhere. This paper highlights a possible source of false positive results (by the vapors of alcohols during the blood spot drying process) in dried blood spots (DBS) by LC-MS/MS quantitation of PEth. To achieve this, the PEth quantitation method was validated according to FDA guidelines. Additionally, the synthesis of phosphatidyl derivatives by phospholipase D (PLD) in the presence of methanol and 2-propanol vapors during the DBS process was determined. Each PEth-negative sample from a healthy male patient incubated in the presence of ethanol vapor becomes PEth-positive. After 4 h of DBS drying, teetotalers become “moderate drinkers”. It is necessary to avoid using alcohol-containing disinfectants in treatment rooms, where DBS is sampled. Full article

(This article belongs to the Section Chromatographic Separations)

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8 pages, 646 KiB

Open AccessArticle

Chemical Composition of the Fixed Oil of Harconia speciosa and Modulation of the Antibiotic Activity against Non-Resistant and MDR Bacterial Strains

by Erlânio O. de Sousa, Maria do Socorro Costa, Cícera Datiane M. Oliveira-Tintino, Carla de Fátima A. Nonato, Jacqueline C. A. Pinheiro, Henrique Douglas M. Coutinho, Irwin Rose A. de Menezes and José Galberto M. Costa

Separations 2022, 9(9), 249; https://doi.org/10.3390/separations9090249 - 7 Sep 2022

Cited by 3 | Viewed by 2001

Abstract

The species Hancornia speciosa (mangabeira) has varied potential. The bark has astringent properties, latex is used for tuberculosis, ulcers, herpes, dermatoses and warts, leaf tea is used for menstrual cramps and the root decoction to treat dislocations and hypertension. The aim of this [...] Read more.

The species Hancornia speciosa (mangabeira) has varied potential. The bark has astringent properties, latex is used for tuberculosis, ulcers, herpes, dermatoses and warts, leaf tea is used for menstrual cramps and the root decoction to treat dislocations and hypertension. The aim of this work was to analyze the chemical composition of the fixed oil and antibacterial activities alone or in association with aminoglycosides against standard and MDR bacteria using broth microdilution assays. In the analysis of the oil by GC/MS, a high content of unsaturated fatty acids (73.46%) was identified in relation to saturated fatty acids (26.15%). Palmitic acid (22.49%) and elaidic acid (69.50%) were the main fatty acids identified. The antibacterial test results showed a more significant oil activity against Staphylococcus aureus SA–ATCC 6538 (MIC = 512 μg/mL). For other strains including standards and multidrug resistant bacteria, the oil presented MIC ≥ 1024 μg/mL. In association with antibiotics, the oil was able to improve antibacterial activity against bacterial strains. A synergic effect was observed for S. aureus SA–10, with MIC reduction of amikacin and gentamicin by 50.00 and 60.00%, respectively. The most significant association was found for Escherichia coli EC–06, with a reduction in MIC of 81.25%. The results indicate that seed oil of H. speciosa has the potential to act on bacterial resistance to aminoglycoside antibiotics. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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17 pages, 1361 KiB

Open AccessArticle

A Resolved Simulation Approach to Investigate the Separation Behavior in Solid Bowl Centrifuges Using Material Functions

by Helene Katharina Baust, Simon Hammerich, Hartmut König, Hermann Nirschl and Marco Gleiß

Separations 2022, 9(9), 248; https://doi.org/10.3390/separations9090248 - 6 Sep 2022

Cited by 5 | Viewed by 2818

Abstract

The separation of finely dispersed particles from liquids is a basic operation in mechanical process engineering. On an industrial scale, continuously operating decanter centrifuges are often used, whose separation principle is based on the density difference between the solid and the liquid phase [...] Read more.

The separation of finely dispersed particles from liquids is a basic operation in mechanical process engineering. On an industrial scale, continuously operating decanter centrifuges are often used, whose separation principle is based on the density difference between the solid and the liquid phase due to high g-forces acting on both phases. The design of centrifuges is based on the experience on the individual manufacturer or simplified black box models, which only consider a stationary state. Neither the physical behavior of the separation process nor the sediment formation and its transport is considered. In this work, a computationally-efficient approach is proposed to simulate the separation process in decanter centrifuges. Thereby, the open-source computation software OpenFOAM was used to simulate the multiphase flow within the centrifuge. Sedimentation, consolidation of the sediment, and its transport are described by material functions which are derived from experiments. The interactions between the particles and the fluid are considered by locally defined viscosity functions. This work shows that the simulation method is suitable for describing the solid-liquid separation in a simplified test geometry of a decanter centrifuge. In addition, the influence of the rheological behavior on the flow in the test geometry can be observed for the first time. Full article

(This article belongs to the Special Issue Research on Separation Performance of Separator)

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11 pages, 924 KiB

Open AccessArticle

Phenolic Composition, Antioxidant and Antibacterial Activities of Extract from Flowers of Rosa damascena from Morocco

by Mounia Chroho, Aziz Bouymajane, Yassine Oulad El Majdoub, Francesco Cacciola, Luigi Mondello, Mustapha Aazza, Touriya Zair and Latifa Bouissane

Separations 2022, 9(9), 247; https://doi.org/10.3390/separations9090247 - 5 Sep 2022

Cited by 20 | Viewed by 3934

Abstract

Rosa damascena is referred to as the queen of roses due to its ornamental, flavoring, and perfuming uses, along with its recognized use in therapy. This study aimed to investigate the total phenols and flavonoids contents, the phenolic compounds, and study the antioxidant [...] Read more.

Rosa damascena is referred to as the queen of roses due to its ornamental, flavoring, and perfuming uses, along with its recognized use in therapy. This study aimed to investigate the total phenols and flavonoids contents, the phenolic compounds, and study the antioxidant and antibacterial properties of the hydroethanolic extract from Rosa damascena flowers, collected from the Middle Atlas of Morocco (Khenifra). The total phenols and flavonoids were assessed using gallic acid and quercetin as standards, and the phenolic compounds were characterized using HPLC-PDA-ESI/MS. The antioxidant activity was evaluated by two methods, namely ferric reducing assay power and total antioxidant capacity. The broth microdilution method was employed to evaluate the antibacterial activity of extract against four bacteria (Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Listeria monocytogenes). Up to 16 phenolic compounds belonging to tannins and flavonoids were positively identified in the Rosa damascena extract. The latter displayed high antioxidant activity and exhibited a bacteriostatic effect against Escherichia coli and a bactericidal effect against Salmonella typhimuriumn, Staphylococcus aureus, and Listeria monocytogenes. As a result, the flowers of Rosa damascena might be employed as natural agents in the pharmaceutical field. Full article

(This article belongs to the Special Issue Methods for the Chemical Analysis and Separation of Compounds in Plants)

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19 pages, 2283 KiB

Open AccessArticle

Determination of Three Alkyl Camphorsulfonates as Potential Genotoxic Impurities Using GC-FID and GC-MS by Analytical QbD

by Kyoungmin Lee, Wokchul Yoo and Jin Hyun Jeong

Separations 2022, 9(9), 246; https://doi.org/10.3390/separations9090246 - 5 Sep 2022

Cited by 2 | Viewed by 2314

Abstract

Camphorsulfonic acid salts are commonly used in the manufacturing production of active pharmaceutical ingredients (APIs) and have the potential to form alkyl camphorsulfonates, which can be considered as potential genotoxic impurities (PGIs). Alkyl camphorsulfonates should be controlled using the Threshold of Toxicological Concern [...] Read more.

Camphorsulfonic acid salts are commonly used in the manufacturing production of active pharmaceutical ingredients (APIs) and have the potential to form alkyl camphorsulfonates, which can be considered as potential genotoxic impurities (PGIs). Alkyl camphorsulfonates should be controlled using the Threshold of Toxicological Concern (TTC) when detected in APIs due to their genotoxicity. An in silico study utilizing the ICH M7 guideline was performed in order to classify the alkyl camphorsulfonates that can be produced from the reaction of camphorsulfonic acid salts with methanol, ethanol, and isopropyl alcohol, which are commonly used solvents in API manufacturing processes. Two sensitive, reproducible, and accurate analytical methods using GC-FID and GC-MS were developed using the analytical Quality By Design (QbD) approaches for the quantitation of three alkyl camphorsulfonates in APIs satisfying the control limit of PGIs according to the TTC. The detection limits of the GC-FID method were found to be between 1.5 to 1.9 ppm, and the detection limits of the GC-MS method were found to be between 0.055 to 0.102 ppm. The method was validated in terms of accuracy, linearity, precision, detection limit, quantitation limit, specificity and robustness. Full article

(This article belongs to the Section Chromatographic Separations)

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18 pages, 1720 KiB

Open AccessArticle

Comparative Elucidation of Aroma, Key Odorants, and Fatty Acid Profiles of Ivorian Shea Butter Prepared by Three Different Extraction Methods

by Kouame Fulbert Oussou, Gamze Guclu, Onur Sevindik, Małgorzata Starowicz, Hasim Kelebek and Serkan Selli

Separations 2022, 9(9), 245; https://doi.org/10.3390/separations9090245 - 5 Sep 2022

Cited by 4 | Viewed by 2356

Abstract

In the present study, the volatile compounds, key odorants, and fatty acid profiles of Ivorian shea butter produced by cold press extraction (CPE), solvent extraction (SE) and traditional extraction (TE) methods were investigated for the first time. The aroma compounds of shea butter [...] Read more.

In the present study, the volatile compounds, key odorants, and fatty acid profiles of Ivorian shea butter produced by cold press extraction (CPE), solvent extraction (SE) and traditional extraction (TE) methods were investigated for the first time. The aroma compounds of shea butter were extracted by the purge and trap method and analyzed by the gas chromatography–mass spectrometry and olfactometry (GC-MS/O) technique. Totals of 51, 49 and 46 aroma compounds were determined in samples from CPE, SE and TE, respectively. It was observed that the volatile compounds of studied material dominated after CPE, in which alcohols (11) were the most abundant chemical group, followed by aldehydes (10) and acids (7). The application of aroma extract dilution analysis (AEDA) resulted in 22, 20, and 16 key odorants in shea butter from CPE, SE and TE, respectively. 3-Hexanol with flavor dilution (FD) factors (2048 in CPS, 1024 in SE and 64 in TE) was found to be the most active aroma compound in all samples. In the fatty acid fraction obtained using the gas chromatography–flame ionization detector (GC-FID) method, 22, 24 and 19 fatty acids were detected in samples after CPE, SE and TE, respectively. The highest number of fatty acids was determined in shea butter using CPE (89.98%). Stearic and oleic acids were the most dominant fatty acids, and all samples of shea butter were rich sources of saturated fatty acids (SFAs). Moreover, the SE samples showed the highest values of DPPH (238.36 µM TEq/kg) and ABTS (534.96 µM TEq/kg), while the CPE samples had the highest total phenolic content (104.64 mg GAE/kg). Principal component analysis (PCA) clearly indicated that the extraction technique could quantitatively or qualitatively induce changes. Thus, this investigation demonstrated that extraction methods have a considerable impact on the quality and chemical composition of the presented material. Full article

(This article belongs to the Section Analysis of Food and Beverages)

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9 pages, 1071 KiB

Open AccessArticle

Antioxidant Activity and Phenolic Content of Sonication- and Maceration-Assisted Ethanol and Acetone Extracts of Cymbopogon citratus Leaves

by Shafeeqa Irfan, Muhammad Mudassar Ali Nawaz Ranjha, Muhammad Nadeem, Muhammad Naeem Safdar, Saqib Jabbar, Shahid Mahmood, Mian Anjum Murtaza, Kashif Ameer and Salam A. Ibrahim

Separations 2022, 9(9), 244; https://doi.org/10.3390/separations9090244 - 5 Sep 2022

Cited by 21 | Viewed by 7506

Abstract

Cymbopogon citratus is a medicinal and well-known aromatic plant which is usually used as a substitute for green-tea with extraordinary phytomedicinal potential. It is of great importance because it offers several promising health effects. The objective of the study was to investigate the [...] Read more.

Cymbopogon citratus is a medicinal and well-known aromatic plant which is usually used as a substitute for green-tea with extraordinary phytomedicinal potential. It is of great importance because it offers several promising health effects. The objective of the study was to investigate the antioxidant activity and total phenolic content of lemongrass leaves extracted by maceration and ultrasound-assisted extraction techniques. Different concentrations of both acetone and ethanol (50% and 70%) as solvents were tested for their radical scavenging activity against the stable free radical DPPH in quantization using a spectrophotometric assay. The ultrasound-assisted extraction technique had advantageous results in the polyphenols extraction yield (26.68%), TPC (61 mg GAE/g of extract) and DPPH (73.85%) compared to the maceration technique. Overall, the results were significant from 50% ethanol and the DPPH results were more significant from 70% ethanol than other concentrations. It is concluded that the ultrasound-assisted extraction is a better extraction technique for polyphenols than other conventional techniques. Full article

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9 pages, 1296 KiB

Open AccessCommunication

Boosting the Liquid Chromatography Separation of Complex Bispecific Antibody Products by Using the Multi-Isocratic Elution Mode

by Amarande Murisier, Valentina D’Atri, Vincent Larraillet, Sebastian Pirner and Davy Guillarme

Separations 2022, 9(9), 243; https://doi.org/10.3390/separations9090243 - 4 Sep 2022

Cited by 3 | Viewed by 2440

Abstract

In reversed-phase liquid chromatography (RPLC), the selectivity between major species and minor variants of protein biopharmaceutical products is always limited. Unfortunately, the stationary phase chemistry, type of mobile phase (organic modifier and salts) and temperature only have a very limited impact on selectivity. [...] Read more.

In reversed-phase liquid chromatography (RPLC), the selectivity between major species and minor variants of protein biopharmaceutical products is always limited. Unfortunately, the stationary phase chemistry, type of mobile phase (organic modifier and salts) and temperature only have a very limited impact on selectivity. Therefore, instead of using a linear elution gradient, we evaluated a recently developed strategy, named the multi-isocratic elution mode, to improve the chromatographic resolution. In this contribution, a generic workflow involving the use of an Excel spreadsheet is provided for the rapid and successful development of multi-isocratic elution methods, without the need to use HPLC modeling software. This simple strategy was then successfully applied to very complex biopharmaceutical products; these included one reduced mAb-cytokine fusion protein and a mAb-domain-fusion (C-terminal) protein sample, containing numerous minor variants that were poorly separated from the major species. The addition of several isocratic steps during the chromatographic run provides a clear added value in terms of chromatographic selectivity for several variants, simplifying characterization of the sample with advanced MS tools. In addition to these advantages, some of the limitations of the multi-isocratic elution mode were also highlighted; these included the need to use a highly precise pumping device (preferably, a binary pumping system) and the need to prepare highly accurate mobile phases. Full article

(This article belongs to the Special Issue Early Career Stars in Separation Analysis of Natural Products and Pharmaceuticals)

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9 pages, 3343 KiB

Open AccessArticle

Speciation of Selenium in Selenium-Enriched Foods by High-Performance Liquid Chromatography-Inductively Coupled Plasma-Tandem Mass Spectrometry

by Yue Luo, Gang Chen, Xiuqing Deng, Hanqing Cai, Xueheng Fu, Fujian Xu, Xiaonian Xiao, Yumeng Huo and Jin Luo

Separations 2022, 9(9), 242; https://doi.org/10.3390/separations9090242 - 3 Sep 2022

Cited by 8 | Viewed by 2546

Abstract

Herein, a method was established for the speciation of six selenium species by high performance liquid chromatography-inductively coupled plasma-tandem mass spectrometry (HPLC-ICP-MS/MS). The factors affecting separation were carefully investigated, including ionic strength, pH, and methanol content. Six species of selenium could be completely [...] Read more.

Herein, a method was established for the speciation of six selenium species by high performance liquid chromatography-inductively coupled plasma-tandem mass spectrometry (HPLC-ICP-MS/MS). The factors affecting separation were carefully investigated, including ionic strength, pH, and methanol content. Six species of selenium could be completely separated within 20 min, under the mobile phase of 25 mM citric acid in pH = 4.0 containing 2% methanol. The detection limits of selenite (Se(IV)), selenate (Se(VI)), selenomethionine (SeMet), selenocystine (SeCys₂), methylselenocysteine (MeSeCys), and selenoethionine (SeEt) were 0.04, 0.02, 0.05, 0.02, 0.03, and 0.15 ng mL⁻¹, respectively. To verify the practicality of this method, the analysis of selenium-enriched foods such as selenium-enriched spring water, selenium-enriched salts, and selenium-enriched tea were conducted, and recovery of 93.7–105% was achieved with RSD < 5%, revealing the high practical utility of the proposed method. Full article

(This article belongs to the Special Issue Applications of Chromatography Technology)

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26 pages, 9761 KiB

Open AccessArticle

Impact of Phenol on Membranes during Bipolar Membrane Electrodialysis for High Salinity Pesticide Wastewater Treatment

by Yuanhui Tang, Wenwen Sun, Yakai Lin, Lin Wang, Hedi Chen, Huanhuan Wu, Lixin Yu and Xiaolin Wang

Separations 2022, 9(9), 241; https://doi.org/10.3390/separations9090241 - 3 Sep 2022

Cited by 1 | Viewed by 2021

Abstract

To achieve a cleaner production, pesticide wastewater with concentrated NaCl can be treated by using a bipolar membrane electrodialysis (BMED) and converted to NaOH and HCl, which minimizes acid and alkali consumption in a pesticide production process. However, ion-exchange membranes (IEMs) are vulnerable [...] Read more.

To achieve a cleaner production, pesticide wastewater with concentrated NaCl can be treated by using a bipolar membrane electrodialysis (BMED) and converted to NaOH and HCl, which minimizes acid and alkali consumption in a pesticide production process. However, ion-exchange membranes (IEMs) are vulnerable to fouling by phenolic substances present in the concentrated NaCl solutions. This work aimed to understand the performance and fouling mechanism of BMED from phenol during the desalination of NaCl and explore an effective cleaning method. The results firstly showed that for the NaCl solutions with higher phenol concentrations, the selectivity of the IEMs was reduced after processing six successive batches of BMED, which led to reverse migration of ions, organics leakage, and an obvious increase in the energy consumption and the concentration of generated acid and alkali. Secondly, IEMs characterization analysis detected that the structure of the IEMs was deformed, while phenol fouling deposits were observed on the surface and interior of the IEMs, especially for the anion exchange membranes (AEMs). Then, the results of soaking tests proved that the phenol could bring about swelling-like degradation to the AEMs and 0.1 wt.% NaOH solution was studied to be the optimized cleaning agent since the performance of the fouled IEMs in the short-running process could be recovered after 5 h of in situ cleaning that removed the phenol fouling deposits efficiently. Finally, the results of a long-running BMED operation treating NaCl solution containing 10 g/L phenol concentration showed that the IEMs were severely fouled, and the fouling was firstly due to the swelling-like mechanism during the initial 12 successive batches, and then should belong to the blockage-like mechanism during the following 20 successive batches. The seriously fouled IEMs could no longer be recovered even after a deep in situ cleaning. This research proves that under appropriate pretreatment or operating conditions, the BMED process is an alternative way of treating wastewater with high salinity and the presence of phenol molecules. Full article

(This article belongs to the Section Materials in Separation Science)

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11 pages, 2974 KiB

Open AccessArticle

Combination of Medium- and High-Pressure Liquid Chromatography for Isolation of L-tryptophan (Q-marker) from Medicago sativa Extract

by Shixuan Zhang, Yonggui Ma, Ronghua Ma, Qilan Wang and Jun Dang

Separations 2022, 9(9), 240; https://doi.org/10.3390/separations9090240 - 2 Sep 2022

Cited by 2 | Viewed by 1871

Abstract

Medicago sativa (alfalfa) is a widely used animal feed. However, its quality has been difficult to control due to the lack of appropriate marker compounds. Therefore, it is very necessary to select an appropriate quality marker (Q-marker) to control its quality. In this [...] Read more.

Medicago sativa (alfalfa) is a widely used animal feed. However, its quality has been difficult to control due to the lack of appropriate marker compounds. Therefore, it is very necessary to select an appropriate quality marker (Q-marker) to control its quality. In this study, medium-pressure liquid chromatography and high-pressure liquid chromatography were employed to effectively prepare the separation of the Q-marker (L-tryptophan) from Medicago sativa. Firstly, using MCI GEL^® CHP20P as the stationary phase, 2.5 g of the target fraction Fr3 was enriched from crude Medicago sativa extract (2.9 kg) by medium-pressure liquid chromatography. Secondly, Sephadex LH-20 was used to further separate Fr3 fractions, and the Fr34 fraction (358.3 mg) was enriched after 14 repetitions. Lastly, using the ReproSil-Pur C18 AQ preparative column, 63.4 mg of L-tryptophan was obtained by high-pressure liquid chromatography, and the purity was above 95%. The results showed that medium-pressure liquid chromatography (MCI GEL^® CHP20P and Sephadex LH-20) combined with high-pressure liquid chromatography (ReproSil-Pur C18 AQ) could be used to effectively prepare the Q-marker from natural products with satisfactory purity. Full article

(This article belongs to the Topic Discovery of Bioactive Compounds from Natural Organisms and Their Molecular Mechanisms against Diseases)

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12 pages, 2356 KiB

Open AccessArticle

Myconoside Affects the Viability of Polarized Epithelial MDCKII Cell Line by Interacting with the Plasma Membrane and the Apical Junctional Complexes

by Aneliya Kostadinova, Galya Staneva, Tanya Topouzova-Hristova, Daniela Moyankova, Vesela Yordanova, Ralitsa Veleva, Biliana Nikolova, Albena Momchilova, Dimitar Djilianov and Rusina Hazarosova

Separations 2022, 9(9), 239; https://doi.org/10.3390/separations9090239 - 2 Sep 2022

Cited by 2 | Viewed by 1739

Abstract

The phenyl glycoside myconoside, extracted from Balkan endemic Haberlea rhodopensis, has a positive effect on human health, but the exact molecular mechanism of its action is still unknown. The cell membrane and its associated junctional complex are the first targets of exogenous compound [...] Read more.

The phenyl glycoside myconoside, extracted from Balkan endemic Haberlea rhodopensis, has a positive effect on human health, but the exact molecular mechanism of its action is still unknown. The cell membrane and its associated junctional complex are the first targets of exogenous compound action. We aimed to study the effect of myconoside on membrane organization and cytoskeleton components involved in the maintenance of cell polarity in the MDCKII cell line. By fluorescent spectroscopy and microscopy, we found that at low concentrations, myconoside increases the cell viability by enhancing membrane lipid order and adherent junctions. The opposite effect is observed in high myconoside doses. We hypothesized that the cell morphological and physicochemical changes of the analyzed cell compartments are directly related to cell viability and cell apical-basal polarity. Our finding contributes to a better understanding of the beneficial application of phytochemical myconoside in pharmacology and medicine. Full article

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

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10 pages, 2564 KiB

Open AccessArticle

Development of an Enzyme-Based Thin-Layer Chromatographic Assay for the Detection of Cyclooxygenase-2 Inhibitors

by Aurélie Urbain, Nidhal Trabelssi and Valérie Bardot

Separations 2022, 9(9), 238; https://doi.org/10.3390/separations9090238 - 2 Sep 2022

Cited by 2 | Viewed by 3194

Abstract

The search for new anti-inflammatory drugs with less side effects requires simple, fast and reliable screening methods. In this context, we have developed a sensitive thin-layer chromatographic (TLC) assay on silica gel plates to detect cyclooxygenase-2 (COX-2) inhibition. COX-2 catalyzes two sequential enzymatic [...] Read more.

The search for new anti-inflammatory drugs with less side effects requires simple, fast and reliable screening methods. In this context, we have developed a sensitive thin-layer chromatographic (TLC) assay on silica gel plates to detect cyclooxygenase-2 (COX-2) inhibition. COX-2 catalyzes two sequential enzymatic reactions: a first oxygenation step that converts arachidonic acid into prostaglandin G₂, and a subsequent reduction of prostaglandin G₂ into prostaglandin H₂. Our test is based on the co-oxidation during this peroxidation step of a co-substrate, N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD), leading to a blue-grey product. As a consequence, COX-2 inhibitors appear on the TLC plate after revelation as clear spots against the colored background. Parameters such as concentrations of enzyme, substrate, and chromogenic reagent have been optimized. The limit of detection was found to be below the microgram for standard COX-2 inhibitors such as celecoxib or ibuprofen. The developed TLC assay was also conclusive when applied to 60 various natural pure compounds and some complex natural extracts. Results demonstrated a COX-2 inhibitory activity mostly for triterpene and sterol derivatives. This COX-2 TLC assay appears as a suitable low-cost and reliable strategy for the screening of natural extracts to discover new anti-inflammatory compounds. Full article

(This article belongs to the Special Issue Liquid Chromatography: Development of Separation Techniques)

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10 pages, 3661 KiB

Open AccessCommunication

Synthesis and Chromatographic Determination of S-Nitrosopantetheine: Exploring Reactivity and Stability in Different Aqueous Solutions

by Daniel Di Risola, Roberto Mattioli, Giulia Mazzoccanti, Simone Manetto, Maurizio Trovato, Mario Fontana, Luciana Mosca and Antonio Francioso

Separations 2022, 9(9), 237; https://doi.org/10.3390/separations9090237 - 1 Sep 2022

Cited by 1 | Viewed by 1552

Abstract

S-nitrosothiols (RSNOs) are a group of sulfur-containing compounds biologically involved in nitric oxide (NO˙) release and signalling pathway. NO˙ plays important physiological and pharmacological activities, particularly in vasodilation and in inducing muscle relaxation. Several RSNO compounds have been detected in [...] Read more.

S-nitrosothiols (RSNOs) are a group of sulfur-containing compounds biologically involved in nitric oxide (NO˙) release and signalling pathway. NO˙ plays important physiological and pharmacological activities, particularly in vasodilation and in inducing muscle relaxation. Several RSNO compounds have been detected in biological systems, and many of them have been chemically synthesized in the laboratory. To date, no works describing the synthesis of the S-nitrosopantetheine (SNOPANT) are reported in the literature. Taking into account that pantetheine is a biological thiol with a crucial function in metabolism, its nitrosylation in vivo could play a role in various metabolic signalling pathways. In this paper, the synthesis and the chromatographic determination of SNOPANT is reported for the first time, as well as a brief investigation of its reactivity in aqueous solutions in the presence of factors known to affect its stability. Full article

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

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16 pages, 4662 KiB

Open AccessArticle

Purification, Identification and Neuroprotective Effects of Proteins from Bombyx batryticatus in Glu-Stimulated PC12 Cells

by Mei-Bian Hu, Xiang-Long Meng, Pu Wang, Shuo-Sheng Zhang, Chun-Jie Wu and Yu-Jie Liu

Separations 2022, 9(9), 236; https://doi.org/10.3390/separations9090236 - 1 Sep 2022

Cited by 2 | Viewed by 1862

Abstract

Bombyx batryticatus (BB) is one of the most commonly used Traditional Chinese Medicines (TCMs) in the treatment of convulsions and epilepsy. The antiepileptic effects of total proteins from BB (BBPs) have been proven in our previous research. In this study, BBPs were further [...] Read more.

Bombyx batryticatus (BB) is one of the most commonly used Traditional Chinese Medicines (TCMs) in the treatment of convulsions and epilepsy. The antiepileptic effects of total proteins from BB (BBPs) have been proven in our previous research. In this study, BBPs were further purified, the neuroprotective effects were evaluated in Glu-stimulated PC12 cells, and the structure was identified by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Six subfractions (PF-1 to PF-6) were obtained by DEAE-52 Sepharose FF ion-exchange chromatography. It was found that PF-1, PF-2, and PF-3, with similar protein compositions, possessed neuroprotective effects in Glu-stimulated PC12 cells by significantly increasing the GABA level, and decreasing the levels of IL-1β and TNF-α. The most active fraction (PF-2) was further separated by Sephadex G-75 gel filtration chromatography, and an effective protein component named PF-2-2 was obtained. Fluorescein isothiocyanate-labeled PF-2-2 (FITC-PF-2-2) was prepared, and the binding of FITC-F-2-2 to the PC12 cells was directly observed with a confocal microscope. PF-2-2 was found to first bind to the surface of PC12 cells and then internalize into the cells. The main band of PF-2-2 was then analyzed by MALDI-TOF/TOF-MS and searched in the MASCOT database; finally a protein named Low molecular mass 30 kDa lipoprotein 21G1 was identified. In conclusion, PF-2-2 and purified proteins isolated from BBPs have potential application prospects in the treatment of epilepsy. Full article

(This article belongs to the Special Issue Separation and Quantitative Analysis of Natural Product Extracts)

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19 pages, 5367 KiB

Open AccessArticle

Optimization of Microwave-Assisted Extraction and Matrix Solid-Phase Dispersion for the Extraction of Polyphenolic Compounds from Grape Skin

by Danijela Ašperger, Marija Gavranić, Barbara Prišlin, Nera Rendulić, Iva Šikuten, Zvjezdana Marković, Bruna Babić, Edi Maletić, Jasminka Karoglan Kontić, Darko Preiner and Ivana Tomaz

Separations 2022, 9(9), 235; https://doi.org/10.3390/separations9090235 - 1 Sep 2022

Cited by 6 | Viewed by 2109

Abstract

Polyphenols are organic compounds that can be found in food, especially in fruits, vegetables, and their products. It was shown that their presence significantly affects the properties of food products and that the consumption of food rich in phenolic compounds has a beneficial [...] Read more.

Polyphenols are organic compounds that can be found in food, especially in fruits, vegetables, and their products. It was shown that their presence significantly affects the properties of food products and that the consumption of food rich in phenolic compounds has a beneficial effect on human health. The subjects of this research were polyphenols: anthocyanins, flavonols, and flavan-3-ols in the skin of grapevine variety Regent. Polyphenols from grape skins were extracted via microwave-assisted extraction (MAE) and matrix solid-phase dispersion (MSPD) as unconventional and green techniques. Therefore, the main aim of this work was to optimize the conditions for the extraction of polyphenolic compounds from grape skin using MAE and MSPD. The extracts were analyzed using high-performance liquid chromatography with a diode array detector and fluorescence detector. Analyses showed that MAE was a very effective method for extracting polyphenolic compounds from grape skin with 10 mL of 60% ethanol for 5 min at 40 °C. The best results for the MSPD extraction of polyphenolic compounds from grape skin were obtained with phenyl as an MSPD sorbent with 10 mL of acetonitrile:water 50:50 v/v as an elution solvent. This scientific research can be used for the better use of grapes as a basis for obtaining flavonoids for commercial purposes. Full article

(This article belongs to the Section Analysis of Food and Beverages)

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22 pages, 1671 KiB

Open AccessArticle

Antioxidant Activity, Total Phenolic and Flavonoid Content and LC–MS Profiling of Leaves Extracts of Alstonia angustiloba

by Nurhidayah Ab. Rahim, Muhammad Nabil Fikri Roslan, Musthahimah Muhamad and Azman Seeni

Separations 2022, 9(9), 234; https://doi.org/10.3390/separations9090234 - 1 Sep 2022

Cited by 13 | Viewed by 4367

Abstract

Plants have a wide range of active compounds crucial in treating various diseases. Most people consume plants and herbals as an alternative medicine to improve their health and abilities. A. angustiloba extract showed antinematodal activity against Bursaphelenchus xylophilus, antitrypanosomal action against Trypanosoma [...] Read more.

Plants have a wide range of active compounds crucial in treating various diseases. Most people consume plants and herbals as an alternative medicine to improve their health and abilities. A. angustiloba extract showed antinematodal activity against Bursaphelenchus xylophilus, antitrypanosomal action against Trypanosoma brucei and anti-plasmodial activity against the chloroquine-resistant Plasmodium falciparum K1 strain. Moreover, it has demonstrated growth inhibitory properties towards several human cancer cell lines, such as MDA-MB-231, SKOV-3, HeLa, KB cells and A431. DPPH and ABTS assays were carried out to determine the antioxidant activity of the aqueous and 60% methanolic extract of A. angustiloba leaves. Moreover, total phenolic and flavonoid contents were quantified. The presence of potential active compounds was then screened using liquid chromatography coupled with a Q-TOF mass spectrometer (LC–MS) equipped with a dual electrospray ionisation (ESI) source. The EC₅₀ values measured by DPPH for the 60% methanolic and aqueous extracts of A. angustiloba leaves were 80.38 and 94.11 µg/mL, respectively, and for the ABTS assays were 85.80 and 115.43 µg/mL, respectively. The 60% methanolic extract exhibited the highest value of total phenolic and total flavonoid (382.53 ± 15.00 mg GAE/g and 23.45 ± 1.04 mg QE/g), while the aqueous extract had the least value (301.17 ± 3.49 mg GAE/g and 9.73 ± 1.76 mg QE/g). The LC–MS analysis revealed the presence of 103 and 140 compounds in the aqueous and 60% methanolic extract, respectively. It consists of phenolic acids, flavonoids, alkaloids, amino acids, glycosides, alkaloids, etc. It can be concluded that the therapeutic action of this plant is derived from the presence of various active compounds; however, further research is necessary to determine its efficacy in treating diseases. Full article

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

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14 pages, 1038 KiB

Open AccessArticle

Homemade Pipette Tip Solid-Phase Extraction for the Simultaneous Determination of 40 Drugs of Abuse in Urine by Liquid Chromatography–Tandem Mass Spectrometry

by Sergi Pascual-Caro, Francesc Borrull, Marta Calull and Carme Aguilar

Separations 2022, 9(9), 233; https://doi.org/10.3390/separations9090233 - 1 Sep 2022

Cited by 5 | Viewed by 3133

Abstract

Pipette tip solid-phase extraction facilitates the handling of low-volume samples and organic solvents in order to achieve more environmentally friendly pre-treatment sample techniques. The use of pipette tip extraction was examined for the quick and simple determination of a heterogeneous group of 40 [...] Read more.

Pipette tip solid-phase extraction facilitates the handling of low-volume samples and organic solvents in order to achieve more environmentally friendly pre-treatment sample techniques. The use of pipette tip extraction was examined for the quick and simple determination of a heterogeneous group of 40 drugs of abuse and some of their metabolites in urine by liquid chromatography coupled to tandem mass spectrometry. Several parameters were studied and optimized, including those which can affect extraction efficiencies, such as the amount of sorbent and the volumes and number of aspirating/dispensing cycles of the sample and organic solvents. The linear range of this method was between the quantification limit and 75 or 100 ng mL⁻¹. Detection limits between 0.025 and 0.500 ng mL⁻¹ and quantification limits from 0.100 to 1.500 ng mL⁻¹ were achieved, which are adequate to determine the studied compounds in urine from drug users. Finally, in order to prove its suitability in toxicological and forensic analyses, the method was successfully applied to 22 urine specimens from women who were starting a detoxification program. Cocaine was the most frequently detected substance, as its presence or the presence of its main metabolite was found in 86% of the analyzed samples. Full article

(This article belongs to the Special Issue Feature Papers in Separations from Editorial Board Members)

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