Liquid Chromatography Electrospray Ionization Quadrupole Research Articles

Profiling of 3-Formyl rifamycin (3-FR) from sintered fixed dose combinations (SDCs) of rifampicin and isoniazid by using RP-HPLC, LC-ESI-QTOF and UPLC/MS/MS

The rapid and severe decomposition of rifampicin in the presence of isoniazid (INH) in a gastric acidic pH environment is a well-reported phenomenon. It is important to note that the significant decomposition problem of RIF has an impact on its bioavailability, which becomes a major issue in fixed dose combinations (FDCs). In this degradation process, RIF will undergo acid hydrolysis and form 3-FR, an acid degradation product of RIF. Further, it will react with INH and form an insoluble iso-nicotinoyl hydrazone (HYD). The formed HYD is probably not stable in the acidic condition, so it will further convert into INH and 3-FR. Consequently, the generation of 3-FR in the acidic stomach environment can be a critical factor contributing to a substantial decline in RIF bioavailability and warrants careful consideration. Hence, it is imperative to explore the presence of 3-FR not only in in vitro dissolution samples but also in in vivo plasma samples. Therefore, the current study focused on the chemical analysis of 3-FR using additively manufactured sintered drug combinations (SDCs) to evaluate its formation, release and qualitative absorption in both in vitro and in vivo settings. High-performance liquid chromatography (HPLC) and liquid chromatography-electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry (LC-ESI-QTOF-MS/MS) were employed for analytical investigations. The developed LC/MS-MS method was employed to investigate the presence of 3-FR in the rabbit's plasma following a single oral administration of SDCs. The study revealed the significant presence of 3-FR in both the in vitro and in vivo plasma samples obtained from the SDCs of RIF and INH. This finding indicates the potential of altering the strategy through additive manufacturing of pH-dependent SDCs to address the critical issue of RIF.

Seasonal and Geographic Dynamics in Bioproperties and Phytochemical Profile of Limonium algarvense Erben.

This study delved into the influence of ecological and seasonal dynamics on the synthesis of secondary metabolites in the medicinal halophyte Limonium algarvense Erben, commonly known as sea lavender, and examined their antioxidant and anti-inflammatory properties. Aerial parts of sea lavender were systematically collected across winter, spring, summer, and autumn seasons from distinct geographic locations in southern Portugal, specifically "Ria de Alvor" in Portimão and "Ria Formosa" in Tavira. The investigation involved determining the total polyphenolic profile through spectrophotometric methods, establishing the chemical profile via liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS), and evaluating in vitro antioxidant properties using radical and metal-based methods, along with assessing anti-inflammatory capacity through a cell model. Results unveiled varying polyphenol levels and profiles across seasons, with spring and autumn samples exhibiting the highest content, accompanied by the most notable antioxidant and anti-inflammatory capacities. Geographic location emerged as an influential factor, particularly distinguishing plants from "Ria de Alvor". Seasonal fluctuations were associated with environmental factors, including temperature, which, when excessively high, can impair plant metabolism, but also with the presence of flowers and seeds in spring and autumn samples, which also seems to contribute to elevated polyphenol levels and enhanced bioproperties of these samples. Additionally, genetic factors may be related to differences observed between ecotypes (geographical location). This study underscores sea lavender's potential as a natural source of antioxidant and anti-inflammatory agents, emphasizing the significance of considering both geographic location and seasonal dynamics in the assessment of phenolic composition and bioactive properties in medicinal plant species.

Metabolomics-derived biomarkers for biosafety assessment of Gd-based nanoparticle magnetic resonance imaging contrast agents.

With the rapid development of nanotechnology and biomedicine, numerous gadolinium (Gd)-based nanoparticle MRI contrast agents have been widely investigated. Due to the unique physicochemical properties of nanoparticles and the complexity of biological systems, the biosafety of Gd-based nanoparticle MRI contrast agents has been paid more and more attention. Herein, for the first time, we employed an ultra-high performance liquid chromatography-electrospray ionization quadrupole time-of-flight/mass spectrometry (UPLC-ESI-QTOF/MS)-based metabolomics approach to investigate the potential toxicity of Gd-based nanoparticle MRI contrast agents. In this work, NaGdF4 and PEG-NaGdF4 nanoparticles were successfully constructed and selected as the representative Gd-based nanoparticle MRI contrast agents for the metabolomics analysis. Based on the results of metabolomics, more metabolic biomarkers and pathways were identified in the NaGdF4 group than those in the PEG-NaGdF4 group. Careful analysis of these metabolic biomarkers and pathways suggested that NaGdF4 nanoparticles induced disturbance of pyrimidine and purine metabolism, inflammatory response, and kidney injury to a certain extent compared with PEG-NaGdF4 nanoparticles. These results indicated that Gd-based nanoparticle contrast agents modified with PEG had better biosafety. Additionally, it was demonstrated that the discovery of characteristic metabolomics biomarkers induced by nanoparticles would provide a new approach for biosafety assessment and stimulate the development of nanomedicine.

Phytochemical profile and anti-inflammatory activity of the hull of γ-irradiated wheat mutant lines (Triticum aestivum L.).

Wheat (Triticum aestivum Linn.; Poaceae) is the second most cultivated food crop among all global cereal crop production. The high carbohydrate content of its grains provides energy, multiple nutrients, and dietary fiber. After threshing, a substantial amount of wheat hull is produced, which serves as the non-food component of wheat. For the valorization of these by-products as a new resource from which functional components can be extracted, the hull from the seeds of cultivated wheat mutant lines bred after γ-irradiation were collected. Untargeted metabolite analysis of the hull of the original cultivar (a crossbreeding cultivar., Woori-mil × D-7) and its 983 mutant lines were conducted using ultra-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry technique. A total of 55 molecules were tentatively identified, including 21 compounds found in the Triticum species for the first time and 13 compounds not previously described. Among them, seven flavonolignans with a diastereomeric structure, isolated as a single compound from the hull of T. aestivum in our previous study, were used as the standards in the metabolite analysis. The differences in their collision cross-section values were shown to contribute to the clear distinction between tricine-lignan stereoisomers. To select functionally active agents with anti-inflammatory activity among the identified compounds, the wheat hull samples were evaluated for their inhibitory effect on nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells. As a result of multivariate analysis based on the results of chemical and biological profiles of the wheat hull samples, 10 metabolites were identified as key markers, contributing to the distinction between active and inactive mutant lines. Considering that one of the four key markers attributed to anti-inflammatory activity has been identified to be a flavonolignan, the wheat hull could be a valuable source of diverse tricin-lignan type compounds and used as a natural health-promoting product in food supplements.

Monoclonal and Oligoclonal Anti-RBC Antibodies Can Mediate Warm Autoimmune Hemolytic Anemia

Background: Recent data from the field of autoimmune platelet antibodies in vaccine-induced immune thrombotic thrombocytopenia (VITT) suggests that antibodies with restricted clonality may be associated with more severe outcomes. Warm autoimmune hemolytic anemia (WAIHA) is an IgG-mediated red blood cell (RBC) disorder. The goal of this study was to investigate the clonality of anti-RBC IgG antibodies in WAIHA, and to assess if clonal restriction was associated with more severe disease course and outcomes. Methods: 15 patients with WAIHA were evaluated. All patients had proven IgG positivity in direct antiglobulin testing (DAT, or “Coombs” test). RBC eluates were prepared and both the patient plasma sample, as well as the RBC eluate, were subject to liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF MS). Based on the number of antibodies seen in the RBC eluate, patients were classified into mono/oligoclonal vs. polyclonal antibody WAIHA groups Assessment of response to treatment was based on international consensus criteria: complete (CR; normal Hb or Hb ≥12 g/dL, with resolution of hemolysis); partial (PR; Hb >10 but <12 g/dL or Hgb >12 g/dL without resolution of hemolysis); or no response (neither CR nor PR). Results: Eleven of the 15 patients (73%) were found to have polyclonal antibodies, while four patients (27%) had mono/oligoclonal WAIHA antibodies. Of these four patients with restricted clonality, two patients had monoclonal antibodies (Figure 1 shows one of the monoclonal WAIHA antibodies identified). There was no significant difference in demographic composition, clinical findings, or treatment received in both groups (Table 1). 66.7% (n=10) of patients were male, and the mean age (SD) was 62.5 years (24.5). Two pediatric patients, ages 10 and 16, were included. Concomitant lymphoproliferative disease was present in 46.7% of the patients. The three most common treatments were steroids (100%), rituximab (93.3%), and splenectomy (13.3%). 40.0% of patients had died at the time of this analysis with no difference between the groups. The number of treatments received were similar between the mono/oligoclonal and polyclonal groups. After the first line of treatment, 100% and 77.8% of the mono/oligoclonal and polyclonal groups respectively achieved PR or CR (P=0.31). Additionally, 100% of the mono/oligoclonal group and 54.5% of the polyclonal group were in PR or CR by their most recent CBC (P=0.10). 50.0% and 54.5% of the mono/oligoclonal group and polyclonal groups respectively relapsed at least once (P=0.25). In those who relapsed, there was an average of 1.0 relapse events in the mono/oligoclonal group compared to 1.7 relapse events in the polyclonal group (P=0.32). Conclusion: This study demonstrates, for the first time, that monoclonal and oligoclonal antibodies can mediate warm autoimmune hemolytic anemia. While these data suggest no difference in clinical outcomes or disease course between patients with mono/oligoclonal vs. polyclonal anti-RBC antibodies, a key limitation is the small sample size.

Impacts of Fermentation on the Phenolic Composition, Antioxidant Potential, and Volatile Compounds Profile of Commercially Roasted Coffee Beans

Fermented coffee beans are believed to have significantly different compositions of phenolic and volatile compounds and physicochemical properties compared to unfermented coffee beans. This study evaluated the effects of fermentation on coffee beans at a commercially roasted level by characterizing their phenolic compounds and semi-quantifying their volatile compounds using liquid chromatography–electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) and headspace/gas chromatography–mass spectrometry (HS-SPME-GC-MS). Coffee beans from two varieties of Coffea arabica, Geisha (G) and Bourbon (B), both fermented beans had higher contents of total phenolic compounds (G: 33.52 mg/g; B: 29.95 mg/g), total flavonoid (G: 0.42 mg/g; B: 0.35 mg/g), total tannins (G: 3.49 mg/g; B: 3.18 mg/g), and higher antioxidant potential in all assays. In total, 131 phenolic compounds were tentatively characterized via LC-ESI-QTOF-MS/MS, where 73 and 65 phenolic compounds were characterized from fermented Geisha and Bourbon, respectively. Regarding GC-MS, the fermented coffee beans had higher levels of phenols, pyrazines, furan, and furanic compounds. These findings substantiated that fermented coffee beans exhibit elevated levels of phenolic and volatile compounds and greater antioxidant activity, which could contribute to relatively higher nutritional values and organoleptic properties.

Comparison of phenolic composition in date (Phoenix dactylifera L.) flesh and seeds extracted by an ultrasonic-assisted and conventional method

ABSTRACT Date palm (Phoenix dactylifera L.) is an important fruit of the Middle East and North Africa with a high content of phenolic compounds. This study applied ultrasonic-assisted and conventional methods to extract phenolic compounds from date flesh and seed. The efficacy of the extraction methods is compared in terms of quantity, content, and antioxidant capacity of phenolic compounds. The highest total phenolic content (TPC) was found in ultrasonic-assisted date seed samples extracted by ethanol (18.53 mg GAE/g). In contrast, the TPC content of conventionally extracted seed samples ranged from 1.30 to 14.46 mg GAE/g. The TPC and antioxidant capacity values of phenolic compounds extracted from date flesh samples were lower than those extracted from seed samples. Liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) was used to characterize phenolic compounds. A total of 47 different phenolic compounds were identified, including 21 phenolic acids, 21 flavonoids, and 5 other polyphenols. High-performance liquid chromatography equipped with a photodiode array detector (HPLC-PDA) was used to quantify the phenolic compounds in different date samples. The highest content was found in ultrasonic-assisted date seed samples extracted in methanol solvent. The extract also contained epicatechin (36.12 μg/g), coumaric acid (27.05 μg/g), p-hydroxybenzoic acid (21.03 μg/g), syringic acid (19.85 μg/g), and epicatechin gallate (11.67 μg/g). The results showed that ultrasonic-assisted extraction could significantly increase the quantities of functional components of the extracts obtained from fresh date fruit samples.

Bioactive Compounds and In Vitro Antioxidant and Anticoccidial Activities of Opuntia ficus-indica Flower Extracts.

The objective of the present study is to identify the biochemical compounds extracted from OFI flowers using ultra-high-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry and to evaluate their in vitro antioxidant activities and anticoccidial effects on the destruction of Eimeria oocysts isolated from naturally infected chickens. A domestic microwave was used with a refrigerant to condense the vapors generated during the extraction. The flavonoid and phenolic compound contents of the OFI flowers were determined according to standard methods. DPPH radical and H2O2 scavenging capacities were used to assess the antioxidant activity. Regarding the anticoccidial activity, the Eimeria spp. oocysts used were isolated from the fresh feces of infected broilers and were determined in triplicate by incubation at an ambient temperature for 24 h. The results highlighted the considerable influence of the optimized acetone concentration, ratio, irradiation time, and microwave power parameters on the phenolic content and antioxidant activities. Our results revealed significant matches between the predicted and experimental values of the models. Molecular analysis revealed the presence of several biophenol classes such as quercetin, isorhamnetin 3-O-rutinoside, and quercetin-3-O-rutinoside. OFI flower extracts inhibited sporulation and damaged the morphology of Eimeria oocysts compared with normal sporulated Eimeria oocysts containing sporocysts. In conclusion, the optimized conditions were validated and found to fit very well with the experimental values. These findings suggest that the flowers of OFI should be considered sources of antioxidants. The results of the present study revealed that OFI flower extracts have anticoccidial activities against Eimeria-spp.-induced infection in broiler chickens.

Proteotypic peptides of hairs for the identification of common European domestic and wild animal species revealed by in-sample protein digestion and mass spectrometry analysis.

The aim of this work is to offer an alternative or complementary analytical tool to the time consuming and expensive methods commonly used for the recognition of animal species according to their hairs. The paper introduces a simple and fast way for species differentiation of animal hairs called in-sample digestion. A total of 10 European animal species, including cat, cow, common degu, dog, fallow deer, goat, horse, sika deer, rabbit, roe deer, and 17 different breeds of dogs were examined using specific tryptic cleavage directly in hair followed by matrix-assisted laser desorption/ionization - time of flight mass spectrometry and liquid chromatography electrospray ionization quadrupole time of flight. Principal component analysis was used for the subsequent mass spectrometric data evaluation. This novel approach demonstrates the ability to distinguish among individual animal species, which is supported by finding characteristic m/z values obtained by the mass spectrometry for each animal species. The approach was successfully tested on two "blind" samples. On the other hand, the attempt to distinguish among hairs of different dog breeds has not been successful due to the very similar protein composition and their amino acid sequences. This article is protected by copyright. All rights reserved.

LC-ESI-QTOF-MS2 Characterization of Phenolic Compounds in Different Lentil (Lens culinaris M.) Samples and Their Antioxidant Capacity.

Lentil (Lens culinaris M.) is a legume widely consumed worldwide. It is rich in bioactive compounds, including polyphenolic compounds that contribute to positive health benefits. This study aimed to determine the phenolic content and antioxidant activity of black, red, green, and brown whole lentils. Towards this end, the lentils' phenolic compounds were evaluated regarding their total phenolic content (TPC), total flavonoid content (TFC), total tannin content (TTC), total condensed tannin (TCT), total proanthocyanin content (TPAC), total anthocyanin content (TAC). For the antioxidant activity 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), hydroxyl radical scavenging activity (•OH-RSA), ferrous ion chelating activity (FICA), reducing power assay (RPA) and phosphomolybdate (PMA) assay were accessed. To identify individual phenolic compounds, liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS2) was used. The results showed that green lentils exhibited the highest TPC (0.96 mg gallic acid equivalents (GAE)/g) whereas red lentils presented the highest TFC (0.06 mg quercetin equivalents (QE)/g). Black lentils were noted with the highest TCT (0.03 mg catechin equivalents (CE)/g), TPAC (0.009 mg cyanidin chloride equivalents (CCE)/g), and TAC (3.32 mg/100 g) contents. While the greatest TTC (2.05 mg tannic acid equivalents (TAE)/g) was observed in the brown lentil. Regarding the total antioxidant capacity, red lentils (4.01 mg ascorbic acid equivalents (AAE)/g) presented the greatest activity, whereas the lowest was found in the brown samples (2.31 mg AAE/g). The LC-ESI-QTOF-MS2 tentatively identified a total of 22 phenolic compounds, containing 6 phenolic acids, 13 flavonoids, 2 lignans, and 1 other polyphenol. The relationships among phenolic compounds by Venn Diagram showed a high number of overlapping compounds in brown and red lentils (6.7%), and a low number of overlapping compounds between the green, brown, and black lentils (2.6%). Flavonoids were the most abundant phenolic compound within the studied whole lentils, with the brown lentils being the richest in phenolic compounds, especially flavonoids. This study emphasized a comprehensive understanding of the antioxidant potential of lentils and disclosed the phenolic distribution across various lentil samples. This may increase interest in the development of functional food products, nutraceutical ingredients, and pharmaceutical applications with lentils.

Screening and characterization of phenolic compounds by LC-ESI-QTOF-MS/MS and their antioxidant potentials in papaya fruit and their by-products activities

Papaya (Carica papaya L.) is one of the most commonly planted and consumed fruits in the world, especially in tropical and subtropical areas. In recent years, due to the diverse range of nutritional value and medicinal properties of bioactive substances possessed in papaya, papaya fruit and their by-products have gained more attention. The present study aimed to characterize the different parts (pulp, peel, and seed) of two varieties of papaya (yellow- and red-fleshed) at different stages of ripeness (unripe and ripe) for their phenolic compounds using liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS). The phenolic content and antioxidant activity were detected through several assays. Yellow-fleshed unripe papaya seed showed the highest total phenolic content (TPC) (4.73 mg GAE/g). Red-fleshed ripe papaya peel exhibited the highest level of total tannin content (TTC) with 1.98 mg CE/g, while red-fleshed unripe peel exhibited the highest total flavonoid content (TFC) with 2.78 ± 0.04 mg QE/g. In terms of antioxidant potential, yellow-fleshed unripe papaya peels had the highest radical scavenging activities for the DPPH, ABTS, and TAC tests. LC-ESI-QTOF-MS/MS experiment successfully tentatively identified 118 phenolic compounds in total, including phenolic acids (35), flavonoids (61), stilbenes (3), lignans (7) and other polyphenols (12) in all papaya samples. Analyses indicate that the three different parts of the papaya fruit are potential sources of phenolic compounds, particularly the peel. The results of this study provide practical data for the potential application of papaya fruit as a functional food ingredient in the food, pharmaceutical and medicinal industries.

Identification of an indole biodegradation gene cluster from Providencia rettgeri and its contribution in selectively biosynthesizing Tyrian purple.

Tyrian purple, mainly composed of 6, 6'-dibromoindigo, is a precious dye extracted from sea snails. In this study, we found Tyrian purple can be selectively produced by a bacterial strain GS-2 when fed with 6-bromotryptophan in the presence of tryptophan. This GS-2 strain was then identified as Providencia rettgeri based on bacterial genome sequencing analysis. An indole degradation gene cluster for indole metabolism was identified from this GS-2 strain. The heterologous expression of the indole degradation gene cluster in Escherichia coli BL21 (DE3) and in vitro enzymatic reaction demonstrated that the indole biodegradation gene cluster may contribute to selectively biosynthesizing Tyrian purple. To further explore the underlying mechanism of the selectivity, we explored the intermediates in this indole biodegradation pathway using liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS), which indicated that the indole biodegradation pathway in Providencia rettgeri is the catechol pathway. Interestingly, the monooxygenase GS-C co-expressed with its corresponding reductase GS-D in the cluster has better activity for the biosynthesis of Tyrian purple compared with the previously reported monooxygenase from Methylophaga aminisulfidivorans (MaFMO) or Streptomyces cattleya cytochrome P450 enzyme (CYP102G4). This is the first study to show the existence of an indole biodegradation pathway in Providencia rettgeri, and the indole biodegradation gene cluster can contribute to the selective production of Tyrian purple.

Evaluation of Two Simultaneous Metabolomic and Proteomic Extraction Protocols Assessed by Ultra-High-Performance Liquid Chromatography Tandem Mass Spectrometry.

Untargeted multi-omics analysis of plasma is an emerging tool for the identification of novel biomarkers for evaluating disease prognosis, and for developing a better understanding of molecular mechanisms underlying human disease. The successful application of metabolomic and proteomic approaches relies on reproducibly quantifying a wide range of metabolites and proteins. Herein, we report the results of untargeted metabolomic and proteomic analyses from blood plasma samples following analyte extraction by two frequently-used solvent systems: chloroform/methanol and methanol-only. Whole blood samples were collected from participants (n = 6) at University Hospital Sharjah (UHS) hospital, then plasma was separated and extracted by two methods: (i) methanol precipitation and (ii) 4:3 methanol:chloroform extraction. The coverage and reproducibility of the two methods were assessed by ultra-high-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS). The study revealed that metabolite extraction by methanol-only showed greater reproducibility for both metabolomic and proteomic quantifications than did methanol/chloroform, while yielding similar peptide coverage. However, coverage of extracted metabolites was higher with the methanol/chloroform precipitation.

Metabolomics Analysis Revealed Significant Metabolic Changes in Brain Cancer Cells Treated with Paclitaxel and/or Etoposide.

Cancer of the central nervous system (CNS) is ranked as the 19th most prevalent form of the disease in 2020. This study aims to identify candidate biomarkers and metabolic pathways affected by paclitaxel and etoposide, which serve as potential treatments for glioblastoma, and are linked to the pathogenesis of glioblastoma. We utilized an untargeted metabolomics approach using the highly sensitive ultra-high-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS) for identification. In this study, 92 and 94 metabolites in U87 and U373 cell lines were profiled, respectively. The produced metabolites were then analyzed utilizing t-tests, volcano plots, and enrichment analysis modules. Our analysis revealed distinct metabolites to be significantly dysregulated (nutriacholic acid, L-phenylalanine, L-arginine, guanosine, ADP, hypoxanthine, and guanine), and to a lesser extent, mevalonic acid in paclitaxel and/or etoposide treated cells. Furthermore, both urea and citric acid cycles, and metabolism of polyamines and amino acids (aspartate, arginine, and proline) were significantly enriched. These findings can be used to create a map that can be utilized to assess the antitumor effect of paclitaxel and/or etoposide within the studied cancer cells.

Nontarget Metabolites of Rhizomes of Edible Sacred Lotus Provide New Insights into Rhizome Browning

The “edible rhizome” variant of Nelumbo nucifera with various cultivars has a long history of use as a food in East Asia. In this study, 48 target metabolites were untargeted and identified in 212 rhizome cultivars (tropical and temperate types) using ultraperformance liquid chromatography-electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry; among these, 32 compounds were newly reported in the rhizome. Combined with the browning phenotype of 212 lotus rhizomes, (epi) catechin, norarmepavine, and N-feruloyl-3-methoxytyramine were used as predominant chemical markers to separate different degrees of lotus rhizome browning. p-Coumaroyltyramine and N-trans-feruloyltyramine were selected as predominant chemical markers to investigate the differential expression between tropical and temperate lotus using principal component analysis and orthogonal partial least squares discriminant analysis. Shared and unique structure plots were used to compare the outcomes of the ecotype and browning OPLS model, showing that variation in tropical lotus rhizome browning is not obvious; this will be of great importance for genetic improvement by providing a hereditary basis.

Antioxidative Properties and Phenolic Profile of the Core, Pulp and Peel of Commercialized Kiwifruit by LC-ESI-QTOF-MS/MS

The kiwifruit is cultivated globally due to its diversity of phytochemicals, especially phenolic compounds, which have antioxidant, anti-inflammatory and anti-cancer medical effects. However, only the pulp of the kiwifruit is consumed, while the peels and cores—which are also rich in phytochemicals—are usually wasted. Meanwhile, detailed information on the comparison among the three parts is still limited. In this study, the antioxidant potentials in the core, pulp, and peel of the three most commercialized kiwifruit cultivars (Australian-grown Hayward kiwifruit, New Zealand-grown Zesy002 kiwifruit, and New Zealand-grown organic Hayward kiwifruit) were selected. Their antioxidant capacities were tested, and their phenolic profiles were identified and characterized by liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS). The antioxidant results showed that the peel of New Zealand-grown organic Hayward kiwifruit contained the highest total phenolic content (9.65 mg gallic acid equivalent (GAE) mg/g) and total antioxidant capacity (4.43 mg ascorbic acid equivalent (AAE) mg/g), respectively. In addition, the antioxidant capacity of the peel is generally higher than that of the pulp and cores in all species, especially ABTS (2,2-Azino-bis-3ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging ability), ranging from 13.25 mg AAE/g to 18.31 mg AAE/g. The LC-ESI-QTOF-MS/MS tentatively identified the phenolic compounds present in the three kiwifruit species, including 118 unique compounds in kiwifruit peel, 12 unique compounds in the kiwifruit cores, and three unique compounds in kiwifruit pulp. The comprehensive characterization of the phenolics in the kiwifruits’ parts indicates the importance of their waste part as a promising source of phenolics with antioxidant properties. Therefore, this study can guide the industry with meaningful information on kiwifruit waste, and can provide it with the utilization of food and pharmacological aspects.

Spectrum-Effect Relationship-Based Strategy Combined with Molecular Docking to Explore Bioactive Flavonoids from Sceptridium ternatum.

Sceptridium ternatum is a herbaceous plant with significant potential for pharmaceutical and cosmetic applications. In this study, we established a spectrum-effect relationship-based strategy to investigate the bioactive basis and tissue distribution in S. ternatum. First, a phytochemical analysis on the ethanol extracts from roots, stems, and leaves of S. ternatum was performed using the colorimetric method, high-performance liquid chromatography–ultraviolet (HPLC–UV), and high-performance liquid chromatography–electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC–ESI-Q-TOF-MS/MS). Then, radical scavenging assays and the lipopolysaccharide-stimulated RAW 264.7 cell model were used to estimate the antioxidant and anti-inflammatory activities, respectively. Spectrum-effect relationship analysis and molecular docking were further employed to evaluate the correlation between the phytochemical profile and anti-inflammatory activity. Our results demonstrate that S. ternatum leaves contained the most abundant flavonoids and exerted the best biological activities. Their IC50 values for scavenging 2,2ʹ-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radicals were 2.43 ± 0.13 and 5.36 ± 0.54 mg/mL, respectively. In lipopolysaccharide-stimulated RAW 264.7 cells, the leaf extract caused the greatest reduction in nitric oxide production (38.15%) and interleukin-6 release (110.86%). Spectrum-effect relationship analysis and molecular docking indicated that quercetin 3-O-rhamnoside-7-O-glucoside possessed high anti-inflammatory activity by binding with interleukin-6. In conclusion, S. ternatum is a rich source of bioactive flavonoids with potential for exploitation in the prevention and treatment of oxidative stress and inflammation-related pathologies.

Effect of processing on polyphenols in butternut pumpkin (Cucurbita moschata)

Pumpkin (Cucurbita moschata) is consumed worldwide with a diverse array of phytochemicals, including phenolics, that have therapeutic properties such as anti-inflammatory, antibacterial, antioxidant, and neuroprotective effects. Nevertheless, detailed information on polyphenol content in pumpkin processing is still limited. Therefore, the present work aimed to investigate the changes in polyphenol content and their antioxidant potential during pumpkin processing, followed by their comprehensive characterization and quantification using liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) and high-performance liquid chromatography–photodiode array (HPLC-PDA). The antioxidant results showed that pumpkins’ seeds and skins (PSS) contained the highest total phenolic content (TPC, 0.39 mg gallic acid equivalent mg/g) and total antioxidant capacity (TAC, 0.35 mg ascorbic acid equivalent mg/g), respectively. However, separated pumpkin puree (SPP) had a higher total condensed tannins content (TCT, 0.15 mg catechin equivalent mg/g). The LC-ESI-QTOF-MS/MS tentatively identified a total of 23 phenolic compounds present in the five pumpkin samples. Through HPLC-PDA quantification, the most abundant phenolic compounds were epicatechin (6.645 μg/g) and catechin (6.146 μg/g) detected in PSS. The comprehensive characterization and quantification of phenolics in processed pumpkins indicate the importance of pumpkins as a promising source of polyphenols with antioxidant properties. This study provides supportive information on the utilization of pumpkin phenolics in the food, pharmacological, and nutraceutical industries.

Rhodomyrtus tomentosa Fruits in Two Ripening Stages: Chemical Compositions, Antioxidant Capacity and Digestive Enzymes Inhibitory Activity.

Rhodomyrtus tomentosa fruit (RTF) has been known as a food source with multiple health-care components. In this work, nutrition characteristics, free and bound phenolic profiles, antioxidant properties in vitro and digestive enzymes inhibitory activities of un-fully mature RTF (UM-RTF) and fully mature RTF (FM-RTF) were evaluated for the first time. Results verified that high levels of energy, ascorbic acid, organic acids and total phenolics were observed in FM-RTF. Moreover, FM-RTF had significant higher total phenolic content (TPC), but significantly lower total flavonoid content (TFC) than UM-RTF. In addition, twenty phenolic compounds in RTF were identified by high performance liquid chromatography–electrospray ionization–quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-qTOF-MS/MS) method. Quantitative analysis results indicated that gallic acid, ellagic acid and astragalin were the predominant free phenolics, while gallic acid and syringetin-3-O-glucoside were dominant in bound phenolic fractions. In contrast, higher contents of phenolics were observed in FM-RTF. The results also confirmed that FM-RTF exhibited higher antioxidant activities and digestive enzymes inhibitory activities than UM-RTF. Strong inhibitory ability on α-glucosidase was found in RTF, while bound phenolics showed a stronger α-amylase inhibitory effect than free phenolics. Moreover, the interaction between the main phenolic compounds and α-glucosidase/α-amylase was preliminary explored by molecular docking analysis. The results provided valuable data about the chemical compositions and biological potential of R. tomentosa fruits in both maturation stages studied.

Metabolic Profiling of Averrhoa carambola Fruit Extract using UHPLC-ESI-QTOF-MS and Determination of the Concentration of Essential Elements using MP-AES

A rapid and sensitive ultra-high-performance liquid chromatography-electrospray ionization quadrupole time of flight mass spectrometry (UHPLC-ESI-QTOF-MS) based method was developed to separate and identify 44 phenolics and non-phenolics present in Averrhoa carambola fruit in three different stages of its growth. 5 anthocyanins, 9 phenolic acids, 3 flavones, 5 flavanols, 3 flavanones, amino acids, vitamins and other phenolic and non-phenolic compounds were identified. The identification and quantification of 27 bioactive compounds from methanolic star fruit extract are being reported for the first time. All the metabolites were quantified by normalizing the area under the peaks with that of the internal standard hydrocortisone. The extraction of metabolites by using a homogeniser (bead beater) was found to be the best method for the extraction of metabolites. Four essential microelements (Zn, Fe, Mn, Cr) and three macroelements (K, Mg, Na) were quantified from star fruit using MP-AES. The zinc concentration (6.988 mg/100 g) in star fruit was found to be higher than in many cereals, vegetables and fruits. The methanolic star fruit extract showed excellent DPPH scavenging activity of 93% after 30 min of incubation in dark for the dry weight sample concentration of 50 mg/ml. In conclusion, the UHPLC-ESI-QTOF-MS based method developed and MP-AES results presented here can be used in the quality control of food supplements and medicines.