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Keywords = electrospray ionisation

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23 pages, 1929 KiB  
Article
Emerging Contaminants in Coastal Landscape Park, South Baltic Sea Region: Year-Round Monitoring of Treated Wastewater Discharge into Czarna Wda River
by Emilia Bączkowska, Katarzyna Jankowska, Wojciech Artichowicz, Sylwia Fudala-Ksiazek and Małgorzata Szopińska
Resources 2025, 14(8), 123; https://doi.org/10.3390/resources14080123 - 29 Jul 2025
Viewed by 252
Abstract
In response to the European Union’s revised Urban Wastewater Treatment Directive, which mandates enhanced monitoring and advanced treatment of micropollutants, this study was conducted. It took place within the Coastal Landscape Park (CLP), a Natura 2000 protected area in northern Poland. The focus [...] Read more.
In response to the European Union’s revised Urban Wastewater Treatment Directive, which mandates enhanced monitoring and advanced treatment of micropollutants, this study was conducted. It took place within the Coastal Landscape Park (CLP), a Natura 2000 protected area in northern Poland. The focus was on the municipal wastewater treatment plant in Jastrzębia Góra, located in a region exposed to seasonal tourist pressure and discharging effluent into the Czarna Wda River. A total of 90 wastewater samples were collected during five monitoring campaigns (July, September 2021; February, May, July 2022) and analysed for 13 pharmaceuticals and personal care products (PPCPs) using ultra-high-performance liquid chromatography tandem mass spectrometry with electrospray ionisation (UHPLC-ESI-MS/MS). The monitoring included both untreated (UTWW) and treated wastewater (TWW) to assess the PPCP removal efficiency and persistence. The highest concentrations in the treated wastewater were observed for metoprolol (up to 472.9 ng/L), diclofenac (up to 3030 ng/L), trimethoprim (up to 603.6 ng/L) and carbamazepine (up to 2221 ng/L). A risk quotient (RQ) analysis identified diclofenac and LI-CBZ as priority substances for monitoring. Multivariate analyses (PCA, HCA) revealed co-occurrence patterns and seasonal trends. The results underline the need for advanced treatment solutions and targeted monitoring, especially in sensitive coastal catchments with variable micropollutant presence. Full article
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14 pages, 3565 KiB  
Article
Synthesis of Lipopeptides Using Vegetable Oils by Newly Isolated Strain of Serratia marcescens G8-1: Genomic Characterization and Process Performance
by Slawomir Ciesielski, Wiktoria Stefańska, Kritika Singh and Ewelina Wielgus
Int. J. Mol. Sci. 2025, 26(12), 5794; https://doi.org/10.3390/ijms26125794 - 17 Jun 2025
Viewed by 365
Abstract
Biosurfactants are becoming increasingly popular, but industrial production of biosurfactants is difficult, partly due to high production costs resulting from the need to use expensive substrates. One economically feasible candidate is vegetable oils, which can be directly metabolized without pretreatment. The aim of [...] Read more.
Biosurfactants are becoming increasingly popular, but industrial production of biosurfactants is difficult, partly due to high production costs resulting from the need to use expensive substrates. One economically feasible candidate is vegetable oils, which can be directly metabolized without pretreatment. The aim of this work is therefore to investigate the possibility of using vegetable oils for lipopeptide production by Serratia marcescens G8-1. The genetic background of this strain for the production of lipopeptides was investigated using a genomic approach. The biosurfactants were analysed by Ultra-Performance Liquid Chromatography coupled with Electrospray Ionisation Mass Spectrometry. The ability to reduce surface tension was investigated using a tensiometer. The results showed that the best effect in reducing surface tension was achieved by adding waste rapeseed oil. Sunflower and linseed oil also showed good results. Significantly poorer results were obtained when fresh rapeseed oil, sesame oil and pumpkin seed oil were used. The putative gene cluster for cyclic lipopeptides NRPS was identified in the genome of S. marcescens G8-1. The results obtained confirmed that serrawettin W1 is the major biosurfactant produced by S. marcescens G8-1. Of particular interest, the results showed the presence of vinylamycin when rapeseed oil was used. Full article
(This article belongs to the Section Macromolecules)
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16 pages, 1210 KiB  
Article
Effect of Thermal Processing by Spray Drying on Key Ginger Compounds
by Alina Warren-Walker, Manfred Beckmann, Alison Watson, Steffan McAllister and Amanda J. Lloyd
Metabolites 2025, 15(6), 350; https://doi.org/10.3390/metabo15060350 - 24 May 2025
Viewed by 817
Abstract
Background/Objectives: Spray drying is a technique widely employed in the food and nutraceutical industries to convert liquid extracts into stable powders, preserving their functional properties. Ginger (Zingiber officinale) is rich in bioactive compounds such as gingerols, shogaols, and zingerone, which contribute [...] Read more.
Background/Objectives: Spray drying is a technique widely employed in the food and nutraceutical industries to convert liquid extracts into stable powders, preserving their functional properties. Ginger (Zingiber officinale) is rich in bioactive compounds such as gingerols, shogaols, and zingerone, which contribute to its health benefits. This study aimed to investigate the impact of spray drying on the chemical profile of ginger, particularly focusing on the transformation of gingerols into shogaols and related compounds. Methods: Fresh ginger juice was spray-dried using various carrier agents, including Clear Gum (CO03), pea protein, and inulin. Mass spectra of the resulting powders were acquired using High-Resolution Flow Infusion Electrospray Ionisation Mass Spectrometry (HR-FIE-MS) to obtain fingerprint data. Key bioactive compounds were tentatively identified to Level 2, and their relative intensities were assessed to evaluate the effects of different carriers on the chemical composition of the ginger powders. Results: Spray drying with the commercial carrier CO03 resulted in an increase in shogaol analogues ([10]-, [8]-, and cis-[8]-shogaol), gingerenone B, and oxidation products such as 6-hydroxyshogaol, 6-dehydroshogaol, and zingerone. In contrast, natural carriers like pea protein and inulin led to lower relative intensities of these bioactives, suggesting limited capacity for promoting thermal transformations. Spray drying without a carrier produced a shogaol-dominant profile but resulted in powders with poor handling properties, such as stickiness and agglomeration. Antioxidant and total polyphenol assays showed that spray drying reduced antioxidant capacity, while total polyphenol content was more preserved; natural carriers such as inulin better maintained bioactivity compared to modified starch or pea protein. Conclusions: Among the five formulations evaluated—ginger juice with no carrier, with CO03 (two dilutions), pea protein, or inulin—CO03-based samples showed the greatest chemical transformation, while inulin and pea protein better preserved antioxidant capacity but induced fewer metabolite changes. Thus, choice of carrier in the spray-drying process influences the chemical profile and functional characteristics of resultant ginger powders. While CO03 effectively enhances the formation of bioactive shogaols and related compounds, its ultra-processed nature may not align with clean-label product trends. Natural carriers, although more label-friendly, may not create the desired chemical transformations. Therefore, optimising carrier selection is important to balance bioactivity, product stability, and consumer acceptability in the development of ginger-based functional products. Full article
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21 pages, 5965 KiB  
Article
Enhancing the Oral Bioavailability of Glutathione Using Innovative Analogue Approaches
by Naibo Yin, Paul W. R. Harris, Mengyang Liu, Jianguo Sun, Guanyu Chen, Jingyuan Wen and Margaret A. Brimble
Pharmaceutics 2025, 17(3), 385; https://doi.org/10.3390/pharmaceutics17030385 - 18 Mar 2025
Cited by 2 | Viewed by 3858
Abstract
Background: Glutathione (GSH) is an essential antioxidant that protects against oxidative stress, but its oral bioavailability is below 1% due to enzymatic degradation and poor gastrointestinal absorption. Improving the oral bioavailability of GSH could significantly enhance its therapeutic efficacy. Methods: This study synthesised [...] Read more.
Background: Glutathione (GSH) is an essential antioxidant that protects against oxidative stress, but its oral bioavailability is below 1% due to enzymatic degradation and poor gastrointestinal absorption. Improving the oral bioavailability of GSH could significantly enhance its therapeutic efficacy. Methods: This study synthesised GSH analogues with chemical modifications to improve bioavailability. Seven GSH derivatives were designed: three analogues with altered stereochemistry (1.62, 1.63, and 1.64) and three N-methylated derivatives (1.65, 1.70, and 1.71), alongside a native GSH (1.61). The analogues were synthesised via Fmoc-solid-phase peptide synthesis, and they were characterised using reverse-phase high-performance liquid chromatography (RP-HPLC), electrospray ionisation mass spectrometry (ESI-MS), Fourier-transform infrared spectroscopy (FTIR), and nuclear magnetic resonance (NMR) spectroscopy. Their toxicity was assessed on Caco-2 cells for viability, and their antioxidant activity was assessed on UVA-irradiated fibroblast cells, enzymatic resistance, and interactions with GSH-metabolising enzymes. Results: Among the tested analogues, the N-methylated cysteine Compound (1.70) emerged as the most promising candidate. Compound 1.70 demonstrated superior resistance to enzymatic degradation, as well as showing enhanced cell viability and improved antioxidant activity. In vivo studies revealed a 16.8-fold increase in plasma half-life (t½) and a 16.1-fold increase in oral bioavailability compared to native GSH. Conclusions: Chemical modification strategies, particularly the N-methylation of GSH, present a viable approach to enhancing oral bioavailability. Compound 1.70 showed significant potential for therapeutic applications, warranting further investigation and development in clinical settings. Full article
(This article belongs to the Section Drug Delivery and Controlled Release)
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16 pages, 5126 KiB  
Article
Chemical Diversity of UK-Grown Tea Explored Using Metabolomics and Machine Learning
by Amanda J. Lloyd, Alina Warren-Walker, Jasen Finch, Jo Harper, Kathryn Bennet, Alison Watson, Laura Lyons, Pilar Martinez Martin, Thomas Wilson and Manfred Beckmann
Metabolites 2025, 15(1), 52; https://doi.org/10.3390/metabo15010052 - 15 Jan 2025
Cited by 4 | Viewed by 1289
Abstract
Background/Objectives: Dartmoor Estate Tea plantation in Devon, UK, is renowned for its unique microclimate and varied soil conditions, which contribute to the distinctive flavours and chemical profiles of tea. The chemical diversity of fresh leaf samples from various garden locations was explored within [...] Read more.
Background/Objectives: Dartmoor Estate Tea plantation in Devon, UK, is renowned for its unique microclimate and varied soil conditions, which contribute to the distinctive flavours and chemical profiles of tea. The chemical diversity of fresh leaf samples from various garden locations was explored within the plantation. Methods: Fresh leaf, which differed by location, cultivar, time of day, and variety, was analysed using Flow Infusion Electrospray Ionisation Mass Spectrometry (FIE-MS). Results: Random forest classification revealed no significant differences between Georgian N2 cultivar garden locations. However, a significant degree of variability was observed within four tri-clonal variants (Tocklai Variety) with TV9 exhibiting greater similarity to the Georgian N2 cultivar compared to TV8 and TV11, while TV11 was found to be most like TV1. The intraclass variability in leaf composition was similar between the varieties. We explored the metabolic changes over the day in one variant (Camellia assamica Masters), yielding a model with a significant R2 value of 0.617 (p < 0.01, 3000 permutations). Starch and sucrose metabolism was found to be significant where the abundance of these chemical features increased throughout the day and then began to decrease at night. Conclusions: This research highlights the complex interplay of cultivars, geographical location, and temporal factors on the chemical composition of tea. It provides insightful data on the metabolic pathways influencing tea cultivation and production and underscores the importance of these variables in determining the final chemical profile and organoleptic characteristics of tea products. Full article
(This article belongs to the Section Plant Metabolism)
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25 pages, 3106 KiB  
Article
Systematic Characterisation of the Fragmentation of Flavonoids Using High-Resolution Accurate Mass Electrospray Tandem Mass Spectrometry
by Candy Jiang and Paul J. Gates
Molecules 2024, 29(22), 5246; https://doi.org/10.3390/molecules29225246 - 6 Nov 2024
Cited by 6 | Viewed by 3834
Abstract
Flavonoids are a class of polyphenolic secondary metabolites found in plants. Due to their ubiquity in our daily dietary intake and their major anti-oxidative, anti-inflammatory and anti-mutagenic activities, they have been a major focus of wide-ranging research for the past two decades. Mass [...] Read more.
Flavonoids are a class of polyphenolic secondary metabolites found in plants. Due to their ubiquity in our daily dietary intake and their major anti-oxidative, anti-inflammatory and anti-mutagenic activities, they have been a major focus of wide-ranging research for the past two decades. Mass spectrometry combined with liquid chromatography is one of the most popular techniques for the analysis of flavonoids. In this study, high-resolution accurate mass electrospray tandem mass spectrometry was used to study 30 flavonoids in both positive and negative ionisation modes. From the data obtained, common losses were summarised and compiled. Dominating neutral losses were tabulated. The radical loss of CH3· was observed in flavonoids containing methoxy groups and three key diagnostic product ions were identified. These were m/z 153 (indicative of two OH groups on ring A) m/z 167 (indicative of one OH and one methoxy group on ring A) and m/z 151 (a flavanol, with no ketone oxygen but two OH groups on ring A). These will be useful in structural elucidation of unknown flavonoids and flavonoid metabolites. Energy breakdown graphs were utilised to distinguish between three pairs of structural isomers, and to help rationalise proposed fragmentation pathways. Lastly, a competition of loss of CH3· and methane was reported for rhamnetin and isorhamnetin in the negative ion mode for the first time. Proposed fragmentation pathways were given to rationalise the differences in peak intensities for this competitive process. Full article
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20 pages, 1457 KiB  
Article
Detailed Profiling of 17-Hydroxygeranyllinalool Diterpene Glycosides from Nicotiana Species Reveals Complex Reaction Networks of Conjugation Isomers
by Alina Ebert, Saleh Alseekh, Lucio D’Andrea, Ute Roessner, Ralph Bock and Joachim Kopka
Metabolites 2024, 14(10), 562; https://doi.org/10.3390/metabo14100562 - 20 Oct 2024
Viewed by 1294
Abstract
Background: Specialised anti-herbivory metabolites are abundant in the solanaceous genus Nicotiana. These metabolites include the large family of 17-hydroxygeranyllinalool diterpene glycosides (HGL-DTGs). Many HGL-DTGs occur exclusively within the Nicotiana genus, but information from the molecular model species N. tabacum, N. benthamiana [...] Read more.
Background: Specialised anti-herbivory metabolites are abundant in the solanaceous genus Nicotiana. These metabolites include the large family of 17-hydroxygeranyllinalool diterpene glycosides (HGL-DTGs). Many HGL-DTGs occur exclusively within the Nicotiana genus, but information from the molecular model species N. tabacum, N. benthamiana, and the tree tobacco N. glauca is limited. Objectives: We studied HGL-DTG occurrence and complexity in these species with the aim of providing in-depth reference annotations and comprehensive HGL-DTG inventories. Methods: We analysed polar metabolite extracts in comparison to the previously investigated wild reference species N. attenuata using positive ESI(+) and negative ESI(-) mode electrospray ionisation LC-MS and MS/MS. Results: We provide annotations of 66 HGL-DTGs with in-source and MS/MS fragmentation spectra for selected HGL-DTGs with exemplary fragment interpretations of ESI(+) as well as less studied ESI(-) spectra. We assemble a potential biosynthesis pathway comparing the presence of HGL-DTGs in N. tabacum, N. glauca, and N. benthamiana to N. attenuata. Approximately one-third of HGL-DTGs are chromatographically resolved isomers of hexose, deoxyhexose, or malonate conjugates. The number of isomers is especially high for conjugates with low numbers of deoxyhexose moieties. Conclusions: We extend the number of known HGL-DTGs with a focus on Nicotiana model species and demonstrate that the HGL-DTG family of N. tabacum plants can be surprisingly complex. Our study provides an improved basis with detailed references to previous studies of wild Nicotiana species and enables inference of HGL-DTG pathways with required enzymes for the biosynthesis of this important family of specialised defence metabolites. Full article
(This article belongs to the Section Plant Metabolism)
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18 pages, 5500 KiB  
Article
Characterisation of Canine and Feline Breast Tumours, Their Metastases, and Corresponding Primary Cell Lines Using LA-REIMS and DESI-MS Imaging
by Adrienn Molnár, Gabriel Stefan Horkovics-Kováts, Nóra Kucsma, Zsuzsanna Szegő, Boglárka Tauber, Attila Egri, Zoltán Szkupien, Bálint András Deák, James S. McKenzie, Julianna Thuróczy, Richard Schäffer, Gitta Schlosser, Gergely Szakács and Júlia Balog
Int. J. Mol. Sci. 2024, 25(14), 7752; https://doi.org/10.3390/ijms25147752 - 15 Jul 2024
Cited by 4 | Viewed by 1649
Abstract
Breast cancer, a complex disease with a significant prevalence to form metastases, necessitates novel therapeutic strategies to improve treatment outcomes. Here, we present the results of a comparative molecular study of primary breast tumours, their metastases, and the corresponding primary cell lines using [...] Read more.
Breast cancer, a complex disease with a significant prevalence to form metastases, necessitates novel therapeutic strategies to improve treatment outcomes. Here, we present the results of a comparative molecular study of primary breast tumours, their metastases, and the corresponding primary cell lines using Desorption Electrospray Ionisation (DESI) and Laser-Assisted Rapid Evaporative Ionisation Mass Spectrometry (LA-REIMS) imaging. Our results show that ambient ionisation mass spectrometry technology is suitable for rapid characterisation of samples, providing a lipid- and metabolite-rich spectrum within seconds. Our study demonstrates that the lipidomic fingerprint of the primary tumour is not significantly distinguishable from that of its metastasis, in parallel with the similarity observed between their respective primary cell lines. While significant differences were observed between tumours and the corresponding cell lines, distinct lipidomic signatures and several phospholipids such as PA(36:2), PE(36:1), and PE(P-38:4)/PE(O-38:5) for LA-REIMS imaging and PE(P-38:4)/PE(O-38:5), PS(36:1), and PI(38:4) for DESI-MSI were identified in both tumours and cells. We show that the tumours’ characteristics can be found in the corresponding primary cell lines, offering a promising avenue for assessing tumour responsiveness to therapeutic interventions. A comparative analysis by DESI-MSI and LA-REIMS imaging revealed complementary information, demonstrating the utility of LA-REIMS in the molecular imaging of cancer. Full article
(This article belongs to the Special Issue Mass Spectrometry in Molecular Biology)
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25 pages, 2150 KiB  
Article
Multimodal Mass Spectrometry Imaging of an Osteosarcoma Multicellular Tumour Spheroid Model to Investigate Drug-Induced Response
by Sophie M. Pearce, Neil A. Cross, David P. Smith, Malcolm R. Clench, Lucy E. Flint, Gregory Hamm, Richard Goodwin, James I. Langridge, Emmanuelle Claude and Laura M. Cole
Metabolites 2024, 14(6), 315; https://doi.org/10.3390/metabo14060315 - 29 May 2024
Cited by 2 | Viewed by 3455
Abstract
A multimodal mass spectrometry imaging (MSI) approach was used to investigate the chemotherapy drug-induced response of a Multicellular Tumour Spheroid (MCTS) 3D cell culture model of osteosarcoma (OS). The work addresses the critical demand for enhanced translatable early drug discovery approaches by demonstrating [...] Read more.
A multimodal mass spectrometry imaging (MSI) approach was used to investigate the chemotherapy drug-induced response of a Multicellular Tumour Spheroid (MCTS) 3D cell culture model of osteosarcoma (OS). The work addresses the critical demand for enhanced translatable early drug discovery approaches by demonstrating a robust spatially resolved molecular distribution analysis in tumour models following chemotherapeutic intervention. Advanced high-resolution techniques were employed, including desorption electrospray ionisation (DESI) mass spectrometry imaging (MSI), to assess the interplay between metabolic and cellular pathways in response to chemotherapeutic intervention. Endogenous metabolite distributions of the human OS tumour models were complemented with subcellularly resolved protein localisation by the detection of metal-tagged antibodies using Imaging Mass Cytometry (IMC). The first application of matrix-assisted laser desorption ionization–immunohistochemistry (MALDI-IHC) of 3D cell culture models is reported here. Protein localisation and expression following an acute dosage of the chemotherapy drug doxorubicin demonstrated novel indications for mechanisms of region-specific tumour survival and cell-cycle-specific drug-induced responses. Previously unknown doxorubicin-induced metabolite upregulation was revealed by DESI-MSI of MCTSs, which may be used to inform mechanisms of chemotherapeutic resistance. The demonstration of specific tumour survival mechanisms that are characteristic of those reported for in vivo tumours has underscored the increasing value of this approach as a tool to investigate drug resistance. Full article
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13 pages, 934 KiB  
Article
Influence of Nutrient Deprivation on the Antioxidant Capacity and Chemical Profile of Two Diatoms from Genus Chaetoceros
by Roberta Frleta Matas, Sanja Radman, Martina Čagalj and Vida Šimat
Mar. Drugs 2024, 22(2), 96; https://doi.org/10.3390/md22020096 - 19 Feb 2024
Cited by 2 | Viewed by 2397
Abstract
The limited availability of phosphate, nitrogen and silicon in the growth media affects the growth, cellular processes, and metabolism of diatoms. Silicon deficiency primarily affects diatom morphology, while phosphate deficiency reduces the production of nucleic acids and phospholipids. Differences in pigment and protein [...] Read more.
The limited availability of phosphate, nitrogen and silicon in the growth media affects the growth, cellular processes, and metabolism of diatoms. Silicon deficiency primarily affects diatom morphology, while phosphate deficiency reduces the production of nucleic acids and phospholipids. Differences in pigment and protein composition are mainly due to nitrogen deficiency. In this study, Chaetoceros socialis and Chaetoceros costatus were cultured under phosphate, nitrogen, and silicon deprivation conditions. The diatom biomass was collected during the stationary growth phase and extracted with 70% ethanol under ultrasonication. The chemical profiles of the extracts were analyzed by high-performance liquid chromatography with high-resolution mass spectrometry with electrospray ionisation (UHPLC-ESI-HRMS), while the antioxidant capacity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbance capacity (ORAC) assays. Pigments, fatty acids, sterols, and derivatives were detected in both species. The total phenolic content in the extracts ranged from 46.25 ± 1.08 to 89.38 ± 6.21 mg of gallic acid equivalent (GAE)/L and from 29.58 ± 1.08 to 54.17 ± 1.18 mg GAE/L. for C. costatus and C. socialis, respectively. Antioxidant activity was higher in C. costatus extracts, especially those obtained from nitrogen-deprived media. The results of this study contribute to the existing knowledge and the ongoing efforts to overcome application and commercialization barriers of microalgae for wide-ranging potential in different industries. Full article
(This article belongs to the Special Issue Metabolites in Marine Planktonic Organisms)
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29 pages, 3373 KiB  
Article
Seasonal Monitoring of Volatiles and Antioxidant Activity of Brown Alga Cladostephus spongiosus
by Sanja Radman, Martina Čagalj, Vida Šimat and Igor Jerković
Mar. Drugs 2023, 21(7), 415; https://doi.org/10.3390/md21070415 - 21 Jul 2023
Cited by 10 | Viewed by 6105
Abstract
Cladostephus spongiosus was harvested once a month during its growing season (from May to August) from the Adriatic Sea. Algal volatile organic compounds (VOCs) were obtained by headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) and analysed by gas chromatography and mass spectrometry (GC-MS). [...] Read more.
Cladostephus spongiosus was harvested once a month during its growing season (from May to August) from the Adriatic Sea. Algal volatile organic compounds (VOCs) were obtained by headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) and analysed by gas chromatography and mass spectrometry (GC-MS). The effects of air drying and growing season on VOCs were determined. Two different extraction methods (ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE)) were used to obtain ethanolic extracts of C. spongiosus. In addition, the seasonal antioxidant potential of the extracts was determined, and non-volatile compounds were identified from the most potent antioxidant extract. Aliphatic compounds (e.g., pentadecane) were predominantly found by HS-SPME/GC-MS. Hydrocarbons were more than twice as abundant in the dry samples (except in May). Aliphatic alcohols (e.g., hexan-1-ol, octan-1-ol, and oct-1-en-3-ol) were present in high percentages and were more abundant in the fresh samples. Hexanal, heptanal, nonanal, and tridecanal were also found. Aliphatic ketones (octan-3-one, 6-methylhept-5-en-2-one, and (E,Z)-octa-3,5-dien-2-one) were more abundant in the fresh samples. Benzene derivatives (e.g., benzyl alcohol and benzaldehyde) were dominant in the fresh samples from May and August. (E)-Verbenol and p-cymen-8-ol were the most abundant in dry samples in May. HD revealed aliphatic compounds (e.g., heptadecane, pentadecanal, (E)-heptadec-8-ene, (Z)-heptadec-3-ene), sesquiterpenes (germacrene D, epi-bicyclosesquiphellandrene, gleenol), diterpenes (phytol, pachydictyol A, (E)-geranyl geraniol, cembra-4,7,11,15-tetraen-3-ol), and others. Among them, terpenes were the most abundant (except for July). Seasonal variations in the antioxidant activity of the ethanolic extracts were evaluated via different assays. MAE extracts showed higher peroxyl radical inhibition activity from 55.1 to 74.2 µM TE (Trolox equivalents). The highest reducing activity (293.8 µM TE) was observed for the May sample. Therefore, the May MAE extract was analysed via high-performance liquid chromatography with high-resolution mass spectrometry and electrospray ionisation (UHPLC-ESI-HRMS). In total, 17 fatty acid derivatives, 9 pigments and derivatives, and 2 steroid derivatives were found. The highest content of pheophorbide a and fucoxanthin, as well as the presence of other pigment derivatives, could be related to the observed antioxidant activity. Full article
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14 pages, 2600 KiB  
Article
Cycloartane Saponins from Astragalus glycyphyllos and Their In Vitro Neuroprotective, Antioxidant, and hMAO-B-Inhibiting Effects
by Ivan Stambolov, Aleksandar Shkondrov, Olaf Kunert, Franz Bucar, Magdalena Kondeva-Burdina and Ilina Krasteva
Metabolites 2023, 13(7), 857; https://doi.org/10.3390/metabo13070857 - 19 Jul 2023
Cited by 7 | Viewed by 2162
Abstract
Astragalus glycyphyllos (Fabaceae) is used in the traditional medicine of many countries against hepatic and cardiac disorders. The plant contains mainly flavonoids and saponins. From a defatted methanol extract from its overground parts, a new triterpenoid saponin, 3-O-[α-L-rhamnopyranosyl-(1→2)]-β [...] Read more.
Astragalus glycyphyllos (Fabaceae) is used in the traditional medicine of many countries against hepatic and cardiac disorders. The plant contains mainly flavonoids and saponins. From a defatted methanol extract from its overground parts, a new triterpenoid saponin, 3-O-[α-L-rhamnopyranosyl-(1→2)]-β-D-xylopyranosyl]-24-O-α-L-arabinopyranosyl-3β,6α,16β,24(R),25-pentahydroxy-20R-cycloartane, together with the rare saponin astrachrysoside A, were isolated using various chromatography methods. The compounds were identified via extensive high resolution electrospray ionisation mass spectrometry (HRESIMS) and NMR analyses. Both saponins were examined for their possible antioxidant and neuroprotective activity in three different in vitro models. Rat brain synaptosomes, mitochondria, and microsomes were isolated via centrifugation using Percoll gradient. They were treated with the compounds in three different concentrations alone, and in combination with 6-hydroxydopamine or tert-butyl hydroperoxide as toxic agents. It was found that the compounds had statistically significant dose-dependent in vitro protective activity on the sub-cellular fractions. The compounds exhibited a weak inhibitory effect on the enzyme activity of human recombinant monoamine oxidase type B (hMAO-B), compared to selegiline. Full article
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10 pages, 637 KiB  
Article
Determination of Glycerol, Propylene Glycol, and Nicotine as the Main Components in Refill Liquids for Electronic Cigarettes
by Paweł Kubica
Molecules 2023, 28(11), 4425; https://doi.org/10.3390/molecules28114425 - 29 May 2023
Cited by 8 | Viewed by 5085
Abstract
Refill liquids for electronic cigarettes are an important area of research due to the health safety and quality control of such products. A method was developed for the determination of glycerol, propylene glycol, and nicotine in refill liquids using liquid chromatography, coupled with [...] Read more.
Refill liquids for electronic cigarettes are an important area of research due to the health safety and quality control of such products. A method was developed for the determination of glycerol, propylene glycol, and nicotine in refill liquids using liquid chromatography, coupled with tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring (MRM) mode with electrospray ionisation (ESI). Sample preparation was based on a simple dilute-and-shoot approach, with recoveries ranging from 96 to 112% with coefficients of variation < 6.4%. Linearity, limits of detection and quantification (LOD, LOQ), repeatability, and accuracy were determined for the proposed method. The proposed sample preparation and the developed chromatographic method using hydrophilic interaction liquid chromatography (HILIC) were successfully applied for the determination of glycerol, propylene glycol, and nicotine in refill liquid samples. For the first time, the developed method using HILIC-MS/MS has been applied for the determination of the main components of refill liquids in a single analysis. The proposed procedure is rapid and straightforward and is suitable for quick determination of glycerol, propylene glycol, and nicotine. The nicotine concentrations corresponded to the labelling of samples (it varied from <LOD—11.24 mg/mL), and the ratios of propylene glycol to glycerol were also determined. Full article
(This article belongs to the Special Issue Advances in Hydrophilic Interaction Liquid Chromatography)
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15 pages, 1158 KiB  
Article
Purification and Molecular Characterization of Fucoidan Isolated from Ascophyllum nodosum Brown Seaweed Grown in Ireland
by Gaurav Rajauria, Rajeev Ravindran, Marco Garcia-Vaquero, Dilip K. Rai, Torres Sweeney and John O’Doherty
Mar. Drugs 2023, 21(5), 315; https://doi.org/10.3390/md21050315 - 21 May 2023
Cited by 25 | Viewed by 5653
Abstract
The present study investigates the molecular characteristics of fucoidan obtained from the brown Irish seaweed Ascophyllum nodosum, employing hydrothermal-assisted extraction (HAE) followed by a three-step purification protocol. The dried seaweed biomass contained 100.9 mg/g of fucoidan, whereas optimised HAE conditions (solvent, 0.1N [...] Read more.
The present study investigates the molecular characteristics of fucoidan obtained from the brown Irish seaweed Ascophyllum nodosum, employing hydrothermal-assisted extraction (HAE) followed by a three-step purification protocol. The dried seaweed biomass contained 100.9 mg/g of fucoidan, whereas optimised HAE conditions (solvent, 0.1N HCl; time, 62 min; temperature, 120 °C; and solid to liquid ratio, 1:30 (w/v)) yielded 417.6 mg/g of fucoidan in the crude extract. A three-step purification of the crude extract, involving solvents (ethanol, water, and calcium chloride), molecular weight cut-off filter (MWCO; 10 kDa), and solid-phase extraction (SPE), resulted in 517.1 mg/g, 562.3 mg/g, and 633.2 mg/g of fucoidan (p < 0.05), respectively. In vitro antioxidant activity, as determined by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging and ferric reducing antioxidant power assays, revealed that the crude extract exhibited the highest antioxidant activity compared to the purified fractions, commercial fucoidan, and ascorbic acid standard (p < 0.05). The molecular attributes of biologically active fucoidan-rich MWCO fraction was characterised by quadruple time of flight mass spectrometry and Fourier-transform infrared (FTIR) spectroscopy. The electrospray ionisation mass spectra of purified fucoidan revealed quadruply ([M+4H]4+) and triply ([M+3H]3+) charged fucoidan moieties at m/z 1376 and m/z 1824, respectively, and confirmed the molecular mass 5444 Da (~5.4 kDa) from multiply charged species. The FTIR analysis of both purified fucoidan and commercial fucoidan standard exhibited O-H, C-H, and S=O stretching which are represented by bands at 3400 cm−1, 2920 cm−1, and 1220–1230 cm−1, respectively. In conclusion, the fucoidan recovered from HAE followed by a three-step purification process was highly purified; however, purification reduced the antioxidant activity compared to the crude extract. Full article
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14 pages, 45692 KiB  
Article
Biological Activity of Cyclic Peptide Extracted from Sphaeranthus amaranthoides Using De Novo Sequencing Strategy by Mass Spectrometry for Cancer
by Swarnalatha Yanamadala, Sivakumar Shanthirappan, Sidhika Kannan, Narendran Chiterasu, Kumaran Subramanian, Lamya Ahmed Al-Keridis, Tarun Kumar Upadhyay, Nawaf Alshammari, Mohd Saeed, Guru Prasad Srinivasan and Rohini Karunakaran
Biology 2023, 12(3), 412; https://doi.org/10.3390/biology12030412 - 7 Mar 2023
Cited by 2 | Viewed by 3337
Abstract
Though there are several advancements and developments in cancer therapy, the treatment remains challenging. In recent years, the antimicrobial peptides (AMPs) from traditional herbs are focused for identifying and developing potential anticancer molecules. In this study, AMPs are identified from Sphaeranthus amaranthoides, [...] Read more.
Though there are several advancements and developments in cancer therapy, the treatment remains challenging. In recent years, the antimicrobial peptides (AMPs) from traditional herbs are focused for identifying and developing potential anticancer molecules. In this study, AMPs are identified from Sphaeranthus amaranthoides, a natural medicinal herb widely used as a crucial immune stimulant in Indian medicine. A total of 86 peptide traces were identified using liquid-chromatography–electrospray-ionisation mass spectrometry (LC-ESI-MS). Among them, three peptides were sequenced using the manual de novo sequencing technique. The in-silico prediction revealed that SA923 is a cyclic peptide with C-N terminal interaction of the carbon atom of ASP7 with the nitrogen atom of GLU1 (1ELVFYRD7). Thus, SA923 is presented under the orbitides class of peptides, which lack the disulfide bonds for cyclization. In addition, SA923, steered with the physicochemical properties and support vector machine (SVM) algorithm mentioned for the segment, has the highest in silico anticancer potential. Further, the in vitro cytotoxicity assay revealed the peptide has anti-proliferative activity, and toxicity studies were demonstrated in Danio rerio (zebrafish) embryos. Full article
(This article belongs to the Section Biochemistry and Molecular Biology)
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