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13 pages, 2066 KiB

Open AccessArticle

Real-Time Authentication of Camellia Oil by Rapid Evaporative Ionization Mass Spectrometry

by Jun Xiang, Qi Liu, Huihua Jing and Xiaoqing Chen

Separations 2024, 11(3), 68; https://doi.org/10.3390/separations11030068 - 24 Feb 2024

Viewed by 1549

Abstract

Camellia oil is a high-value product with rich nutrients. Recently, the adulteration of camellia oil has become an increasingly concerning issue related to human health. In this study, electric soldering iron coupled with rapid evaporative ionization mass spectrometry (REIMS) was employed for the [...] Read more.

Camellia oil is a high-value product with rich nutrients. Recently, the adulteration of camellia oil has become an increasingly concerning issue related to human health. In this study, electric soldering iron coupled with rapid evaporative ionization mass spectrometry (REIMS) was employed for the identification and analysis of camellia oil without any sample preparation. REIMS technology coupled with chemometrics was applied to develop an analysis model for the authentication of camellia oil adulterated with soybean oil, peanut oil, rapeseed oil, sunflower oil, and corn oil (5–40%, v/v). The results showed that different types of vegetable oils could be classified using principal component analysis-linear discriminant analysis (PCA-LDA) with a correct classification of 93.8% in leave-20%-out cross-validation and 100% correctly identified in real-time recognition. The established prediction models were found to be particularly sensitive when the camellia oil samples were adulterated with 5–40% of other oils, indicating that REIMS could be a powerful tool for the authentication and adulteration analysis of camellia oil, particularly for cases where the adulteration levels are relatively high. In conclusion, the results provide valuable insights into the potential of REIMS for the rapid, accurate, and real-time authentication and adulteration analysis of camellia oil. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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16 pages, 1989 KiB

Open AccessArticle

Phytochemical Content and Anticancer Activity of Jamaican Dioscorea alata cv. White Yam Extracts

by Kenroy Wallace, Racquel Wright, Melisa Williams-Longmore, Sasha-Gay Wright and Helen Asemota

Separations 2024, 11(2), 44; https://doi.org/10.3390/separations11020044 - 30 Jan 2024

Viewed by 2485

Abstract

Dioscorea spp. is known for its myriad medicinal properties. D. alata, specifically crude extracts, have displayed potent anticancer properties. However, the chemical constituents of these extracts have not been examined. The aim of this study is to determine the chemical composition and [...] Read more.

Dioscorea spp. is known for its myriad medicinal properties. D. alata, specifically crude extracts, have displayed potent anticancer properties. However, the chemical constituents of these extracts have not been examined. The aim of this study is to determine the chemical composition and antioxidant characteristics of the active extracts from D. alata tuber. Chemoinformatic profiling of the Jamaican Dioscorea alata cultivar white yam tuber was generated by a sequential Soxhlet extraction of dried milled tuber, producing five crude extracts: hexane (E-1), diethyl ether (E-2), acetone (E-3), ethanol (E-4) and water (E-5). The analytes within the five extracts were dissolved in 0.1% DMSO and their anticancer activity was determined using DU145 prostate cancer cells. Both the acetone and the ethanolic extract were able to induce greater than 50% cell death at 50 µg/mL. The order of growth inhibition of the extracts in DU-145 cell is E3 (IC₅₀, 10.81 µg/mL) > E-4 (IC₅₀ 24.17 µg/mL) > E-1 (IC₅₀ > 100 µg/mL) ≥ E-2 (IC₅₀ > 100 µg/mL) ≥ E-5 (IC₅₀ > 100 µg/mL). Phytochemical screening of both E-3 and E-4 revealed the presence of all major classes of secondary metabolites except tannins. Resins were also absent in the E-3 extract. Phenolic quantification indicated that E-3 and E-4 possessed GAEs of 31 ± 1.1 and 72 ± 1.8 mg per g of sample, respectively. Inversely, E-3 displayed greater antioxidant capability with IC₅₀ of 82.9 µg/mL compared to E-4 (166.9 µg/mL); however, neither was comparable to citric acid (33.6 µg/mL). The extract E-3 was further isolated by HPLC into 11 fractions. Fractions 4 and 5 possessed potent cell growth inhibitory effects. GCMs of fractions 4 and 5 showed they possessed numerous saturated fatty acids with pharmacological relevance. The presence of these compounds shows potential for exploitation of D. alata extracts for pharmacological purposes. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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18 pages, 1766 KiB

Open AccessArticle

HPLC and SFC Enantioseparation of (±)-Trans-β-Lactam Ureas on Immobilized Polysaccharide-Based Chiral Stationary Phases—The Introduction of Dimethyl Carbonate as an Organic Modifier in SFC

by Mladenka Jurin, Darko Kontrec and Marin Roje

Separations 2024, 11(2), 38; https://doi.org/10.3390/separations11020038 - 25 Jan 2024

Cited by 4 | Viewed by 1899

Abstract

A series of nine racemic trans-β-lactam ureas were analyzed for enantiomer separation by high-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). The separations were performed on three immobilized polysaccharide-based chiral analytical columns (CHIRAL ART Amylose-SA, CHIRAL ART Cellulose-SB and CHIRAL ART [...] Read more.

A series of nine racemic trans-β-lactam ureas were analyzed for enantiomer separation by high-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). The separations were performed on three immobilized polysaccharide-based chiral analytical columns (CHIRAL ART Amylose-SA, CHIRAL ART Cellulose-SB and CHIRAL ART Cellulose-SC). In HPLC mode, a normal-phase consisting of n-hexane/2-PrOH (90/10, v/v), a polar organic mobile phase consisting of 100% MeOH or 100% EtOH, and a non-standard mobile phase consisting of 100% dimethyl carbonate (DMC) were investigated. In SFC mode, the mobile phases CO₂/alcohol (80/20, v/v) and CO₂/DMC/alcohol (MeOH or EtOH; 70/24/6, v/v/v or 60/32/8, v/v/v) were investigated. The best achieved enantioseparation of trans-β-lactam ureas was obtained with an Amylose-SA column. We have shown that the green solvent dimethyl carbonate (DMC) can be efficiently used as a mobile phase in HPLC mode as well as in SFC mode along with the addition of polar organic modifiers (MeOH or EtOH). Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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14 pages, 1859 KiB

Open AccessArticle

The Simultaneous Determination of Nine Furocoumarins in Angelica dahurica Using UPLC Combined with the QAMS Approach and Novel Health Risk Assessment Based on the Toxic Equivalency Factor

by Zhao Wang, Ke Zan, Xiao-Wen Hu, Shuai Kang, Hai-Liang Li, Tian-Tian Zuo, Hong-Yu Jin and Shuang-Cheng Ma

Separations 2023, 10(9), 508; https://doi.org/10.3390/separations10090508 - 15 Sep 2023

Cited by 1 | Viewed by 1338

Abstract

Objective: This study aimed to provide data for the type and content of linear furocoumarins (FCs) in Angelica dahurica (AD) in order to assess their cumulative risks and provide a scientific basis for the rational use and quality evaluation of the medicinal AD [...] Read more.

Objective: This study aimed to provide data for the type and content of linear furocoumarins (FCs) in Angelica dahurica (AD) in order to assess their cumulative risks and provide a scientific basis for the rational use and quality evaluation of the medicinal AD to improve public health. Methods: A UPLC method was developed for the simultaneous determination of nine FCs initially by using imperatorin (Im) as the internal standard substance, including Im, phellopterin (Ph), isoimperatorin (Is), oxypeucedanin hydrate (Oh), byakangelicin (Bn), xanthotoxin (8-MOP), bergapten (5-MOP), byakangelicol (Bl), and oxypeucedanin (Op) in two species of Angelica dahurica (AD). And, the risk assessment for the total FCs in AD was explored using the hazard index combined with the toxic equivalency factor (TEF-HI) strategy for the first time. Results: The established method revealed acceptable applicability, and there were no significant differences compared with the external standard method (ESM). The quantitative results demonstrated that the total content of FCs in Angelica dahurica (BZ) were higher than that in Angelica dahurica var. formosana (HBZ), and there was a great difference between the Bl and Op. Moreover, the risk assessment data revealed that the risk of total FCs in AD to human health was low. Conclusions: The established UPLC method that determined nine FCs in AD using a single marker could solve the problem of difficulty in obtaining a chemical reference substance with high purity and requiring a long determination time. And, the TEF-HI risk assessment approach associated with FCs in ADs could guide the rational utilization of toxic FCs in ADs in the progress of improving public health safety. In short, the whole systematic strategy provides a scientific basis for rational quality evaluation and the healthy use of related herbal medicines. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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15 pages, 3967 KiB

Open AccessArticle

Green Synthesis of Zinc Oxide Nanoparticles Using Aqueous Extracts of Hibiscus cannabinus L.: Wastewater Purification and Antibacterial Activity

by Xitao Yang, Xuan Cao, Chenxiao Chen, Liping Liao, Sitian Yuan and Siqi Huang

Separations 2023, 10(9), 466; https://doi.org/10.3390/separations10090466 - 24 Aug 2023

Cited by 7 | Viewed by 3574

Abstract

The green preparation of metal oxide nanoparticles is an environmentally friendly method, which could reduce the use of toxic solvents and their impact on the environment. The purpose of this study is to investigate the green synthesis of zinc oxide (ZnO) nanoparticles using [...] Read more.

The green preparation of metal oxide nanoparticles is an environmentally friendly method, which could reduce the use of toxic solvents and their impact on the environment. The purpose of this study is to investigate the green synthesis of zinc oxide (ZnO) nanoparticles using extracts of Hibiscus cannabinus leaves and to evaluate their potential applications in environmental remediation. In this work, ZnO nanoparticles were successfully prepared and thoroughly characterized using UV–vis, Fourier transform infrared analysis (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM) analysis, and scanning electron microscope (SEM) with energy dispersive x-ray analysis (EDAX). As a result, the synthesized ZnO nanoparticles showed a good adsorption capacity for Congo red (CR), and satisfactory antioxidant and antibacterial activities. They exhibited good adsorption and removal abilities for CR in aqueous solutions. With the conditions optimized, the adsorption kinetics and isotherms were fitted to the pseudo-second-order model and the Langmuir model. The ZnO nanoparticles could also effectively scavenge 2-2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-di(3-ethylbenzthiazoline sulphonate) (ABTS) radicals, and appeared to inhibit the growth of Escherichia coli and Staphylococcus aureus bacteria. Based on the identified adsorption capacity, the green synthesized ZnO nanoparticles demonstrated their potential to be used in the removal of dyeing wastewater and in the further purification of water due to their antioxidant activity and antibacterial activity. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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11 pages, 2195 KiB

Open AccessFeature PaperArticle

Determining the Hydrophobicity Index of Protected Amino Acids and Common Protecting Groups

by Varshitha Gavva, Othman Al Musaimi, Colin Bent and Daryl R. Williams

Separations 2023, 10(8), 456; https://doi.org/10.3390/separations10080456 - 20 Aug 2023

Cited by 3 | Viewed by 2944

Abstract

Peptides are in great demand in the pharmaceutical arena and a majority of these peptides contain 20 or more amino acids. They are infrequently synthesised using the fragment condensation approach. A key limitation in adopting this approach more commonly is that protected peptide [...] Read more.

Peptides are in great demand in the pharmaceutical arena and a majority of these peptides contain 20 or more amino acids. They are infrequently synthesised using the fragment condensation approach. A key limitation in adopting this approach more commonly is that protected peptide fragments with high purity are often required prior to the final condensation steps. It is hypothesized that understanding the hydrophobic nature of the protected amino acids will assist with designing optimal fragment purification processes when needed. Whilst a myriad of hydrophobicity indices are reported in the literature for unprotected amino acids, the literature lacks any data regarding the protected amino acids which form the key precursor for the fragment condensation task. In this current study, hydrophobicity indices for protected amino acids with common α-amino and sidechain protecting groups were experimentally determined. Different positions for each amino acid within the peptide chain were considered, namely at the C-terminal and N-terminal as well as internal positions. These data give deep insights on the hydrophobicity of each amino acid with respect to its position in the peptide chain. The data acquired in this research facilitated the prediction of the retention time of protected peptide fragments with an uncertainty of less than ±1.5%. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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15 pages, 2835 KiB

Open AccessArticle

Development and Validation for Quantitative Determination of Genotoxic Impurity in Gemfibrozil by Gas Chromatography with Mass Spectrometry

by Hari Naga Prasada Reddy Chittireddy, J. V. Shanmukha Kumar, Anuradha Bhimireddy, Mohammed Rafi Shaik, Mohammad Rafe Hatshan, Mujeeb Khan, Abdulrahman Alwarthan and Baji Shaik

Separations 2023, 10(3), 145; https://doi.org/10.3390/separations10030145 - 21 Feb 2023

Cited by 4 | Viewed by 2740

Abstract

All regulatory organizations are paying close attention to the identification and measurement of genotoxic contaminants. Using conventional analytical techniques like high-performance liquid chromatography (HPLC) and gas chromatography to quantify probable genotoxic substances (PGIs) at the trace level is difficult (GC). Therefore, there is [...] Read more.

All regulatory organizations are paying close attention to the identification and measurement of genotoxic contaminants. Using conventional analytical techniques like high-performance liquid chromatography (HPLC) and gas chromatography to quantify probable genotoxic substances (PGIs) at the trace level is difficult (GC). Therefore, there is a necessity for advanced analytical techniques for the development of highly sensitive analytical procedures for the determination of trace-level PGIs in drug products and drug substances. This study’s goal is to develop and evaluate an analytical technique for measuring allyl chloride, a possible genotoxic contaminant in gemfibrozil. For the detection of very low and trace levels of impurities, a gas chromatography with a triple quadrupole mass spectrometry detector (GC-MS/MS) approach was developed and validated. Using a column USP phase G27, a nonpolar and low bleed 5% diphenyl, 95% dimethylpolysiloxane, with dimensions of 30 m in length, 0.32 mm internal diameters, and 1.5 m film thickness, along with a flow rate of 2.0 mL/min and Helium (He) as a carrier gas, this method uses a thermal gradient elution program. The method was calibrated with a linearity range from 30% to 150% concentration with respect to the specification level and achieved a limit of detection (LOD) and limit of quantification (LOQ) were 0.005 ppm and 0.01 ppm, respectively, for allyl chloride. According to current ICH requirements, the method was validated, and it was discovered to be specific, exact, accurate, linear, sensitive, tough, robust, and stable. This method is suitable for determining allyl chloride in the regular analysis of Gemfibrozil. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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14 pages, 3441 KiB

Open AccessArticle

Efficient Extraction of Flavonoids from Lotus Leaves by Ultrasonic-Assisted Deep Eutectic Solvent Extraction and Its Evaluation on Antioxidant Activities

by Liangliang Liu, Aiping Xiao, Yi Zhang and Shengwen Duan

Separations 2023, 10(2), 65; https://doi.org/10.3390/separations10020065 - 17 Jan 2023

Cited by 6 | Viewed by 2843

Abstract

The discovery of a green extraction solvent for natural plants could promote related research. In this study, deep eutectic solvents (DES) were used as green solvents coupled with an ultrasound-assisted extraction method (UAE) to extract flavonoids from lotus leaves. Thirty-four different DES were [...] Read more.

The discovery of a green extraction solvent for natural plants could promote related research. In this study, deep eutectic solvents (DES) were used as green solvents coupled with an ultrasound-assisted extraction method (UAE) to extract flavonoids from lotus leaves. Thirty-four different DES were performed and choline chloride/urea with 40% water was chosen as the most promising one, and the related parameters in the procedures were optimized, resulting in the highest extraction amount of flavonoids in lotus leaves. D-101 was selected from four macroporous resins to separate the flavonoids from DES. Moreover, DES could be recycled and efficiently reused four times with satisfactory performances. In addition, the lotus leaf flavonoids from the DES extract exhibited antioxidant activities in five kinds of assays including DPPH, ABTS, Fe³⁺ reducing, FRAP, and Fe²⁺ chelating. It also showed antibacterial activities on Staphylococcus aureus and Escherichia coli bacterial strains with minimal inhibitory concentrations at 1666 μg/mL and 208 μg/mL, respectively. In the HPLC analysis, the three main components in the DES extract were identified as astragalin, hyperoside, and isoquercitrin. In conclusion, the developed UAE-DES followed by macroporous resin treatment could become an efficient and environmentally friendly extraction and enrichment method for flavonoids from lotus leaves and other natural products. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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12 pages, 11497 KiB

Open AccessArticle

Bioassay-Guided Isolation and Identification of Antibacterial Components against Escherichia coli from Industrial Hemp Leaves

by Yafen Fu, Siyuan Zhu, Shengwen Duan and Liangliang Liu

Separations 2023, 10(1), 35; https://doi.org/10.3390/separations10010035 - 6 Jan 2023

Cited by 2 | Viewed by 2614

Abstract

Industrial hemp leaves have raised much interest in nutraceuticals and functional foods areas. To expand its application ranges, the antibacterial activities of industrial hemp leaf extract on Escherichia coli, Staphylococcus aureus, and Bacillus cereus were evaluated and the active components were [...] Read more.

Industrial hemp leaves have raised much interest in nutraceuticals and functional foods areas. To expand its application ranges, the antibacterial activities of industrial hemp leaf extract on Escherichia coli, Staphylococcus aureus, and Bacillus cereus were evaluated and the active components were screened. As a result, the industrial hemp leaf extract was found to have strong bacteriostatic effects on E. coli and S. aureus. Bioassay-guided fractionation and isolation from fractions active against E. coli were conducted. Two compounds, cannabidivarinic acid and cannabidiolic acid, were firstly recognized by analytical HPLC by comparing the retention times and UV spectra with standards and later isolated using preparative HPLC. Moreover, the antibacterial mechanisms of cannabidivarinic acid and cannabidiolic acid were investigated by testing the alkaline phosphatase activity, β-galactosidase activity, conductivity, proteins leakage, nucleic acid leakage, and scanning electron microscope observation. The results demonstrated that cannabidivarinic acid and cannabidiolic acid could destroy the cell wall and membrane of E. coli, resulting in the inhibition of enzyme activity and leakage of contents. They could damage the bacteria cell envelope as well. Presented results pointed out cannabidivarinic acid and cannabidiolic acid as promising natural bacteriostatic agents for the food, pharmaceutical, and cosmetic industry. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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13 pages, 1843 KiB

Open AccessArticle

Improved Quantitative Approach for Monitorization of Gangliosides Structural Diversity in Fungal Cell Factories by LC-MS/MS

by Javier-Fernando Montero-Bullón, Javier Martín-González, Gloria Muñoz-Fernández, Alberto Jiménez and José Luis Revuelta

Separations 2022, 9(12), 432; https://doi.org/10.3390/separations9120432 - 12 Dec 2022

Viewed by 1730

Abstract

Gangliosides are glycolipids occurring in higher animals, with a sphingoid core in the form of ceramide, bound to a glycan moiety including several units of sialic acid. Gangliosides are involved in important (patho)-physiological processes as components of cell membranes in humans, which has [...] Read more.

Gangliosides are glycolipids occurring in higher animals, with a sphingoid core in the form of ceramide, bound to a glycan moiety including several units of sialic acid. Gangliosides are involved in important (patho)-physiological processes as components of cell membranes in humans, which has led to intensive study and interest in production strategies. Their structural variability depends on the combination of a sphingoid base, a fatty acyl chain, and an attached oligosaccharide. The combinatorial diversity differs and grows exponentially in synthetic biology approaches, e.g., use of microbial cell factories. A specific analytical platform accounting for this complexity is not available to date. However, quantification of the intermediates of the whole biosynthetic route is needed to boost projects on biotechnological ganglioside production. In this study, a fast high-throughput quantitative LC-MS/MS methodology was developed to cover analysis of gangliosides, with a wider structural perspective adapted to fungal organisms. This work was achieved using metabolically engineered strains that further allowed to test detection in biological complex matrixes. Ganglioside backbones—hitherto uncharacterized—with the five most common fungal sphingoid bases and both simple and hydroxylated fatty acids were subjected to characterization. The addition of glycans to the polar head was also successfully monitored with up to 4 units—corresponding to GD3 which bears two sialic acid units and furthermore represents the common precursor for the whole ganglio-series. This platform represents an improved methodology to study the biochemical diversity associated to gangliosides for natural and metabolically engineered biosynthetic pathways. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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12 pages, 1211 KiB

Open AccessArticle

Validation, Optimization and Hepatoprotective Effects of Boeravinone B and Caffeic Acid Compounds from Boerhavia diffusa Linn

by Kamal Y. Thajudeen, Abdulrhman Alsayari, Shehla Nasar Mir Najib Ullah, Shahana Salam, Muhammed Elayadeth-Meethal and Ilyas Uoorakkottil

Separations 2022, 9(7), 177; https://doi.org/10.3390/separations9070177 - 18 Jul 2022

Cited by 3 | Viewed by 2604

Abstract

Boerhavia diffusa, also known as Punarnava, is a plant of the Nyctaginaceae family that has been utilized in traditional medicine to cure a variety of ailments. The goal of this study was to use response surface methodology (RSM) to optimize the maximum percentage [...] Read more.

Boerhavia diffusa, also known as Punarnava, is a plant of the Nyctaginaceae family that has been utilized in traditional medicine to cure a variety of ailments. The goal of this study was to use response surface methodology (RSM) to optimize the maximum percentage yield of boeravinone B and caffeic acid from Boerhavia diffusa roots, and simultaneous determination of boeravinone B and caffeic acid in newly developed single solvent system and demonstrate the hepatoprotective benefits of boeravinone B and caffeic acid. The extraction process examined extraction time, extraction temperature and solvent concentration, which were optimized via Box–Behnken experimental design. The proposed HPTLC method for the quantification of boeravinone B and caffeic acid were successfully validated and developed. The method was validated in term of linearity and detection limit, quantification limit, range, precision, specificity and accuracy. The separation of boeravinone B and caffeic acid bands was achieved on HPTLC plate using formic acid: ethyl acetate: toluene (1:3:5 v/v) as developing system. Densitometric analyses of boeravinone B and caffeic acid was carried out in the absorbance mode at 254 nm. The maximum percentage yield of caffeic acid and boeravinone B from Boerhavia diffusa require appropriate extraction parameters such as temperature, time, organic solvents and water content, which can be achieved using the Box-Behnken statistical design provide time: temperature: solvent ratio (30:45:40 v/v) for extraction of caffeic acid and 60:60:40 v/v for extraction of boeravinone B. The boeravinone B (200 µg/mL) and caffeic acid (200 µg/mL) showed the most significant hepatoprotective activity compared with standard sylimarin in HepG2 cell induced with galactosamine 40 mM toxicity. The findings supported B. diffusa’s traditional use as a functional food forhuman health benefits. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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21 pages, 5370 KiB

Open AccessArticle

Enantioseparation of syn- and anti-3,5-Disubstituted Hydantoins by HPLC and SFC on Immobilized Polysaccharides-Based Chiral Stationary Phases

by Mladenka Jurin, Darko Kontrec, Tonko Dražić and Marin Roje

Separations 2022, 9(7), 157; https://doi.org/10.3390/separations9070157 - 22 Jun 2022

Cited by 6 | Viewed by 3124

Abstract

The enantioseparation of syn- and anti-3,5-disubstituted hydantoins 5a–i was investigated on three immobilized polysaccharide-based columns (CHIRAL ART Amylose-SA, CHIRAL ART Cellulose-SB, CHIRAL ART Cellulose-SC) by high performance liquid chromatography (HPLC) using n-hexane/2-PrOH (90/10, v/v) or [...] Read more.

The enantioseparation of syn- and anti-3,5-disubstituted hydantoins 5a–i was investigated on three immobilized polysaccharide-based columns (CHIRAL ART Amylose-SA, CHIRAL ART Cellulose-SB, CHIRAL ART Cellulose-SC) by high performance liquid chromatography (HPLC) using n-hexane/2-PrOH (90/10, v/v) or 100% dimethyl carbonate (DMC) as mobile phases, respectively, and by supercritical fluid chromatography (SFC) using CO₂/alcohol (MeOH, EtOH, 2-PrOH; 80/20, v/v) as a mobile phase. The chromatographic parameters, such as separation and resolution factors, have indicated that Amylose-SA is more suitable for enantioseparation of the most analyzed syn- and anti-3,5-disubstituted hydantoins than Celullose-SB and Cellulose-SC in both HPLC and SFC modalities. All three tested columns showed better enantiorecognition ability toward anti-hydantoins compared to syn-hydantoins, both in HPLC and SFC modes. We have demonstrated that environmentally friendly solvent DMC can be efficiently used as the mobile phase in HPLC mode for enantioseparation of hydantoins on the immobilized polysaccharide-based chiral stationary phases. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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Review

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37 pages, 1502 KiB

Open AccessEditor’s ChoiceReview

Factors Influencing the Prediction Accuracy of Model Peptides in Reversed-Phase Liquid Chromatography

by Othman Al Musaimi, Oscar M. Mercado-Valenzo and Daryl R. Williams

Separations 2023, 10(2), 81; https://doi.org/10.3390/separations10020081 - 24 Jan 2023

Cited by 3 | Viewed by 2613

Abstract

Hydrophobicity is an important physicochemical property of peptides in solution. As well as being strongly associated with peptide stability and aggregation, hydrophobicity governs the solution based chromatographic separation processes, specifically reversed-phase liquid chromatography (RPLC). In addition, hydrophobicity is a major physicochemical property of [...] Read more.

Hydrophobicity is an important physicochemical property of peptides in solution. As well as being strongly associated with peptide stability and aggregation, hydrophobicity governs the solution based chromatographic separation processes, specifically reversed-phase liquid chromatography (RPLC). In addition, hydrophobicity is a major physicochemical property of peptides in comparison to H-bonding, electrostatic, and aromatic properties in intermolecular interactions. However, a wide range of molecular factors can influence peptide hydrophobicity, with accurate predictions depending on specific peptide amino acid compositions, structure, and conformation. It is noticeable that peptide composition, the position of the amino acid, and its neighbouring groups play a crucial role in the elution process. In light of this, the same amino acid behaved differently depending on its position and neighbouring amino acid in the peptide chain. Extra attention should be paid to the denaturation process during the course of elution, as it has been shown to complicate and alter the elution pattern. This paper reports on the key peptide properties that can alter hydrophobicity and, consequently, the RPLC elution behaviour of the peptides, and it will conclude by proposing improved prediction algorithms for peptide elution in RPLC. Full article

(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)

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