Reversed-phase ultra-high-performance liquid chromatography coupled to electrospray ionization-quadrupole-time-of-flight mass spectrometry as a powerful tool for metabolic profiling of vegetables: Lactuca sativa as an example of its application

Network pharmacology and UPLC/MS/MS metabolic profiling unveil the anti-inflammatory potential of Trifolium alexandrinum

Trifolium alexandrinum, commonly known as berseem clover, has long been used in traditional medicine for its diverse therapeutic properties. In this study, we explore the anti-inflammatory potential of T. alexandrinum through an integrated approach combining network pharmacology and LC-MS/MS metabolic profiling. The ethanolic extract of T. alexandrinum was fractionated and analyzed, revealing a rich profile of phytoconstituents, including flavonoids, isoflavonoids, triterpenoid glycosides, and purine nucleosides. Network pharmacology analysis identified key bioactive compounds, such as tryptophan and adenosine, which exhibited strong interactions with inflammation-related genes, including TNF-α, IL-6, IL-1β, and INF-γ, as demonstrated from the "compound-target-pathway" constructed network. The arachidonic acid metabolism pathway, which plays a pivotal role in inflammation, was the top-listed pathway in the network. For the sake of confirmation, tryptophan and adenosine were isolated from the butanol fraction, and their structures were elucidated using 1H-NMR, 13C-DEPTQ, and HRESI-MS. In vitro studies using LPS-stimulated WI38 human fibroblast cells demonstrated that the butanol fraction of the extract significantly reduced the expression of pro-inflammatory cytokines, with adenosine and tryptophan showing particularly potent anti-inflammatory effects comparable to the synthetic drug piroxicam. These findings suggest that T. alexandrinum and its constituents, particularly polar compounds in the butanol fraction, hold promise as natural anti-inflammatory agents. This study not only elucidates the molecular mechanisms underlying the anti-inflammatory properties of T. alexandrinum but also highlights its potential as a functional food ingredient with both nutritional and therapeutic benefits.

Storage Time in Bottle: Influence on Physicochemical and Phytochemical Characteristics of Wine Spirits Aged Using Traditional and Alternative Technologies

Few studies have investigated the influence on physicochemical and phytochemical compositions during storage in the bottle of wine spirits (WSs) aged using alternative ageing technology (AAT) compared to traditional ageing technology (TAT). The aim of this study was to evaluate the effect of the bottle storage over one and four years on the evolution of chromatic characteristics (CIELab method) and physicochemical characteristics (alcoholic strength, acidity, and total dry extract), total phenolic index (TPI), low molecular weight compound contents (HPLC-DAD technique), in vitro antioxidant activities (DPPH, FRAP, and ABTS assays), and phenolic characterisation (HPLC-DAD-ESI-MS/MS technique) of WSs aged with chestnut wood using TAT (barrels, B) and AAT (micro-oxygenation levels (MOX): O15, O30, and O60; and control (N)). The results showed that after four years of storage in the bottle, the O60 modality resulted in smaller changes in physicochemical characteristics, higher preservation of phenolic content, and greater evolution of chromatic characteristics, ensuring its overall quality compared to other modalities. Antioxidant activity decreased similarly in both technologies, such as phenolic acid content, in particular, gallic acid content. According to the findings of this study, alternative ageing technology might be the best alternative for wine spirit quality and ageing process sustainability.

Lactuca racemosa Willd., Source of Antioxidants with Diverse Chemical Structures

Ethanolic extracts from the roots and aerial parts of the hitherto chemically uninvestigated lettuce species Lactuca racemosa Willd. (Cichorieae, Asteraceae) were chromatographically separated to obtain eight sesquiterpenoids, two apocarotenoids (loliolide and (6S,9S) roseoside), and three phenolic glucosides (apigenin 7-O-glucoside, eugenyl-4-O-β-glucopyranoside, and 5-methoxyeugenyl-4-O-β-glucopyranoside). Four of the isolated sesquiterpene lactones (8-α-angeloyloxyleucodin, matricarin, 15-deoxylactucin, and deacetylmatricarin 8-β-glucopyranoside) have not previously been found either in Lactuca spp. or in Cicerbita spp. In addition, HPLC-PAD chromatographic methods were used to estimate the deacetylmatricarin derivatives, luteolin 7-O-glucoside, and caffeic acid derivatives contents in the analyzed plant material. The aerial parts contained c. 3.0% dry weight of chicoric acid and equal amounts (0.4%) of caftaric acid and luteolin 7-O-glucoside. The roots contained fewer phenolic metabolites but were rich in deacetylmatricarin glucoside (c. 1.3%). The aglycone of the most abundant sesquiterpene lactone was evaluated with respect to its neuroprotective effect in H2O2- and 6-OHDA-treated human neuroblastoma SH-SY5Y cells. This compound, at concentrations of 10 and 50 μM, provided partial protection of undifferentiated cells, and at a concentration of 50 μM, it provided partial protection of retinoic acid-differentiated cells from H2O2-induced damage. In a model of 6-OHDA-evoked cytotoxicity, the sesquiterpenoid was less effective. Our findings may support the inclusion of this plant into the human diet.

Non-targeted LC-MS metabolomics reveal shifts from wound-induced enzymatic browning to lignification during extended storage of fresh-cut lettuce in modified atmosphere packaging

Modified Atmosphere Packaging (MAP) is a conventional method used to prolong the shelf-life of fresh-cut vegetables, including lettuce. However, MAP-stored lettuce remains perishable, and its deterioration mechanism is not fully understood. Here, we utilized non-targeted LC-MS metabolomics to evaluate the effects of cutting and extended storage time on metabolite profiles of lettuce stored in MAP. Additionally, hyperspectral imaging was used to measure perceptual changes. Our findings reveal a bipartite response to wounding. In early storage, enzymatic browning was the main response to wounding, evidenced by accumulation of caffeic acid derivatives and flavonoids, substrates for polyphenol oxidases. As storage progressed, enzymatic browning was inhibited, and a shift towards lignification became apparent, evidenced by accumulation of monolignol derivatives. These findings offer new insights into the deterioration mechanism of fresh-cut lettuce occurring in MAP.

Formulating a Horseradish Extract in Phospholipid Vesicles to Target the Skin

Background/Objectives: Horseradish (Armoracia rusticana L.) roots-largely used in traditional medicine for their multiple therapeutic effects-are a rich source of health-promoting phytochemicals. However, their efficacy can be compromised by low chemical stability and poor bioavailability. Incorporation into phospholipid vesicles is often proposed to tackle this problem. Methods: In this study, a hydroalcoholic extract was produced from horseradish roots. The extract was characterized by UPLC-MS and HPLC-PDA and formulated in conventional liposomes and Penetration Enhancer-containing Vesicles (PEVs) for skin application. Results: The obtained nanovesicles were small in size (<100 nm), negatively charged, uni/bilamellar, and with high values of entrapment efficiency (>85%) for the flavonoids identified in the extract. Both the free and the nanoformulated extract showed optimal biocompatibility, measured as the absence of hemolysis of erythrocytes and absence of cytotoxicity in skin cell lines. Furthermore, the nanoformulations displayed antioxidant activity in vitro. Conclusions: The proposed nananoformulations could be exploited to counteract oxidative stress involved in the pathogenesis and progression of numerous skin disorders.

Oilseed Cakes: A Promising Source of Antioxidant, and Anti-Inflammatory Agents-Insights from Lactuca sativa

This study evaluated the antioxidant and antibacterial properties of methanolic extracts derived from oilseed cakes of Lactuca sativa (lettuce), Nigella sativa (black seed), Eruca sativa (rocket), and Linum usitatissimum (linseed). Lettuce methanolic extract showed the highest potential, so it was selected for further investigation. High-performance liquid chromatography (HPLC-DAD) analysis and bioassay-guided fractionation of lettuce seed cake extract led to the isolation of five compounds: 1,3-propanediol-2-amino-1-(3',4'-methylenedioxyphenyl) (1), luteolin (2), luteolin-7-O-β-D-glucoside (3), apigenin-7-O-β-D-glucoside (4), and β-sitosterol 3-O-β-D-glucoside (5). Compound (1) was identified from Lactuca species for the first time, with high yield. The cytotoxic effects of the isolated compounds were tested on liver (HepG2) and breast (MCF-7) cancer cell lines, compared to normal cells (WI-38). Compounds (2), (3), and (4) exhibited strong activity in all assays, while compound (1) showed weak antioxidant, antimicrobial, and cytotoxic effects. The anti-inflammatory activity of lettuce seed cake extract and compound (1) was evaluated in vivo using a carrageenan-induced paw oedema model. Compound (1) and its combination with ibuprofen significantly reduced paw oedema, lowered inflammatory mediators (IL-1β, TNF-α, PGE2), and restored antioxidant enzyme activity. Additionally, compound (1) showed promising COX-1 and COX-2 inhibition in an in vitro enzymatic anti-inflammatory assay, with IC50 values of 17.31 ± 0.65 and 4.814 ± 0.24, respectively. Molecular docking revealed unique interactions of compound (1) with COX-1 and COX-2, suggesting the potential for targeted inhibition. These findings underscore the value of oilseed cakes as a source of bioactive compounds that merit further investigation.

Phytochemical profiling of Livistona carinensis leaf extract via UHPLC-QTOF-MS/MS with assessment of its antiviral mechanisms

Among 36 species of the genus Livistona (family Palmae or Arecaceae), L. carinensis is considered the only species native to Africa. Previous studies showed the richness of Livistona fruits in phenolic compounds. The goal of the current study was to investigate the phytochemical composition and assess the antiviral mechanisms of the L. carinensis leaves' ethanolic extract cultivated in Egypt for the first time. The ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS/MS) was applied. Moreover, the total crude extract was fractionated using ethyl acetate and n-butanol for phytochemical investigations by various chromatographic and spectroscopic techniques. Besides, the antiviral activity of L. carinensis leaves was assessed using three protocols in vitro using MTT assay compared to acyclovir. UHPLC-QTOF-MS/MS-based analysis resulted in identification of 72 metabolites tentatively. They belonged to diverse phytochemical classes, mainly including flavonoids (29), organic acids (10), and phenolic acids (7). The antiviral activity investigations revealed a direct Adeno virus inactivation mechanism rather than inhibition of virus replication or blocking its attachment to Vero cells. Hence, the plant leaves may be a potential candidate for discovery of novel antiviral drugs owing to the diversity of identified phytochemical classes.

Microwave-Assisted Extraction of Secondary Metabolites Using Ethyl Lactate Green Solvent from Ambrosia arborescens: LC/ESI-MS/MS and Antioxidant Activity

Alternative solvents are being tested as green solvents to replace the traditional organic solvents used in both academy and industry. Some of these are already available, such as ethyl lactate, cyrene, limonene, glycerol, and others. This alternative explores eco-friendly processes for extracting secondary metabolites from nature, thus increasing the number of unconventional extraction methods with lower environmental impact over conventional methods. In this context, the Peruvian Ambrosia arborescens was our model while exploring a microwave-assisted extraction (MAE) approach over maceration. The objective of this study was to perform a phytochemical study including UHPLC-ESI-MS/MS and the antioxidant activity of Ambrosia arborescens, using sustainable strategies by mixing both microwaves and ethyl lactate as a green solvent. The results showed that ethyl lactate/MAE (15.07%) achieved a higher extraction yield than methanol/maceration (12.6%). In the case of the isolation of psilostachyin, it was similar to ethyl lactate (0.44%) when compared to methanol (0.40%). Regarding UHPLC-ESI-MS/MS studies, the results were similar. Twenty-eight compounds were identified in the ethyl lactate/MAE and methanol/maceration extracts, except for the tentative identification of two additional amino acids (peaks 4 and 6) in the MeOH extract. In relation to the antioxidant assay, the activity of the ethyl lactate extract was a little higher than the methanol extract in terms of ORAC (715.38 ± 3.2) and DPPH (263.04 ± 2.8). This study on A. arborescens demonstrated that the unconventional techniques, such as MAE related to ethyl lactate, could replace maceration/MeOH for the extraction and isolation of metabolites from diverse sources. This finding showed the potential of unconventional methods with green solvents to provide eco-friendly methods based on green chemistry.

Antimicrobial evaluation of Tripleurospermum callosum (Boiss. & Heldr.) E. Hossain extracts using in vitro and in vivo Caenorhabditis elegans model against urinary system pathogens

Tripleurospermum callosum (Boiss. & Heldr.) E. Hossain was recorded in Turkish ethnobotanical data for its use against urinary and respiratory system ailments. Infusion, decoction and 96% ethanol extracts of T. callosum aerial parts were prepared for in vitro antimicrobial activity against urinary system pathogens Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027, Klebsiella aerogenes ATCC 1348 and Candida albicans ATCC 10231. The non-toxic concentrations of extracts and in vivo antimicrobial assay were performed using C. elegans. The extracts were analysed by Liquid Chromatography Mass Spectrometry (LC-MS/MS) for phytochemical composition. The water extracts were non-toxic at between 5000 and 312 µg/mL, while 96% ethanol extract at 312 µg/mL for C. elegans. The infusion extract showed in vivo anti-infective effect 5000-312 μg/mL against Gram-negative strains. The results indicate a potential role of plant extracts with relatively non-toxic and anti-infective effects against urinary system pathogens.

Phenolic Compound, Antioxidant, Antibacterial, and In Silico Studies of Extracts from the Aerial Parts of Lactuca saligna L

Medicinal plants are considered a major source for discovering novel effective drugs. To our knowledge, no studies have reported the chemical composition and biological activities of Moroccan Lactuca saligna extracts. In this context, this study aims to characterize the polyphenolic compounds distributed in hydro-methanolic extracts of L. saligna and evaluate their antioxidant and antibacterial activities; in addition, in silico analysis based on molecular docking and ADMET was performed to predict the antibacterial activity of the identified phenolic compounds. Our results showed the identification of 29 among 30 detected phenolic compounds with an abundance of dicaffeoyltartaric acid, luteolin 7-glucoronide, 3,5-di-O-caffeoylquinic acid, and 5-caffeoylquinic acid with 472.77, 224.30, 196.79, and 171.74 mg/kg of dried extract, respectively. Additionally, antioxidant activity assessed by DPPH scavenging activity, ferric reducing antioxidant power (FRAP) assay, and ferrous ion-chelating (FIC) assay showed interesting antioxidant activity. Moreover, the results showed remarkable antibacterial activity against Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and Listeria monocytogenes with minimum inhibitory concentrations between 1.30 ± 0.31 and 10.41 ± 0.23 mg/mL. Furthermore, in silico analysis identified three compounds, including Apigenin 7-O-glucuronide, Quercetin-3-O-glucuronide, and 3-p-Coumaroylquinic acid as potent candidates for developing new antibacterial agents with acceptable pharmacokinetic properties. Hence, L. saligna can be considered a source of phytochemical compounds with remarkable activities, while further in vitro and in vivo studies are required to explore the main biological activities of this plant.

Effect of Different Walnut and Hazelnut Leaf Compost Treatments on Yield and Phenolic Composition of Lactuca sativa L

The use of compost made from the leaves of Juglans regia has long been controversial because of its inhibitory effect due to the presence of juglone. Therefore, the aim of our study was to replicate the typical habits of farmers and gardeners, where the dried leaves are collected at the end of the season and placed in a composter. Then, the effects of the different treatments on the yield of the plant (lettuce), secondary metabolism, and possible toxicity of the compost of the grown plant were evaluated. The lowest yield of lettuce was obtained in soil with composted walnut and hazelnut leaves, while the highest yield was recorded in in soil with compost control, soil with composted walnut leaves and grass with the addition of composting agent and soil with composted walnut leaves with addition of composting agent. Some allelochemicals were still present in the compost but at such low levels that they did not affect yield. We suggest that dry walnut leaves and cut grass can be used for composting, while dry hazelnut leaves still contain some allelochemicals after two years that significantly inhibit plant growth and thus yield, so we would not recommend their use for composting.

Characterization of Health Beneficial Components in Discarded Leaves of Three Escarole (Cichorium endivia L.) Cultivar and Study of Their Antioxidant and Anti-Inflammatory Activities

Plants of genus Cichorium (Asteraceae) can be used as vegetables with higher nutritional value and as medicinal plants. This genus has beneficial properties owing to the presence of a number of specialized metabolites such as alkaloids, sesquiterpene lactones, coumarins, unsaturated fatty acids, flavonoids, saponins, and tannins. Cichorium endivia L., known as escarole, has achieved a common food status due to its nutritionary value, bitter taste, and the presence of healthy components, and is eaten cooked or raw in salads. Presently, wastes derived from the horticultural crops supply chain are generated in very large amounts. Vegetable waste comprises the discarded leaves of food sources produced during collection, handling, transportation, and processing. The external leaves of Cichorium endivia L. are a horticultural crop that is discarded. In this work, the phytochemical profile, antioxidant, and anti-inflammatory activities of hydroalcoholic extract obtained from discarded leaves of three cultivars of escarole (C. endivia var. crispum 'Capriccio', C. endivia var. latifolium 'Performance' and 'Leonida') typical horticultural crop of the Campania region were investigated. In order to describe a metabolite profile of C. endivia cultivars, the extracts were analysed by HR/ESI/Qexactive/MS/MS and NMR. The careful analysis of the accurate masses, the ESI/MS spectra, and the ¹H NMR chemical shifts allowed for the identification of small molecules belonging to phenolic, flavonoid, sesquiterpene, amino acids, and unsaturated fatty acid classes. In addition, the antioxidant potential of the extracts was evaluated using cell-free and cell-based assays, as well as their cytotoxic and anti-inflammatory activity. All the extracts showed similar radical-scavenging ability while significant differences between the three investigated cultivars emerged in the cell-based assays. The obtained data were ascribed to the content of polyphenols and sesquiterpenes in the extracts. Accordingly, C. endivia by-products can be deemed an interesting material for healthy product formulations.

In Vitro, In Silico, and In Vivo Studies of Cardamine hirsuta Linn as a Potential Antidiabetic Agent in a Rat Model

Diabetes mellitus (T2DM) is a multifaceted metabolic disorder with no definite treatment. In silico characterization can help to explain the interaction between molecules and predict 3D structures. The aim of the present study was to evaluate the hypoglycemic activities of the hydro-methanolic extract of Cardamine hirsuta in a rat model. In vitro antioxidant and α-amylase inhibitory assays were evaluated in the present study. Phyto-constituents were quantified using RP-UHPLC-MS analysis. Molecular docking of compounds into the binding site of different molecular targets, i.e., tumor necrosis factor (TNF-α), glycogen synthase kinase 3 β (GSK-3β), and AKT, was carried out. Acute toxicity model, in vivo antidiabetic effect, and the influence on biochemical and oxidative stress parameters were also investigated. T2DM was induced in adult male rats by streptozotocin using a high-fat diet model. Three different doses (125, 250, and 500 mg/kg BW) were orally gavaged for 30 days. Mulberrofuran-M and quercetin3-(6″caffeoylsophoroside) have demonstrated remarkable binding affinity toward TNF-α and GSK-3β, respectively. 2,2-Diphenyl-1-picrylhydrazyl and α-amylase inhibition assay exhibited IC50 values of 75.96 and 73.66 μg/mL, respectively. In vivo findings exhibited that 500 mg/kg body weight (BW) dose of the extract significantly decreased the blood glucose level, improved biochemical parameters as well as oxidative stress by reduction of lipid peroxidation, and increased high-density lipoproteins. Moreover, activities of glutathione-s-transferase, reduced glutathione, superoxide dismutase were enhanced, and cellular architecture in the histopathological examination was restored in treatment groups. The present study affirmed the antidiabetic activities of mulberrofuran-M and quercetin3-(6″caffeoylsophoroside) present in the hydro-methanolic extract of C. hirsuta, possibly due to the reduction in oxidative stress and α-amylase inhibition.

Comprehensive Metabolite Profiling of Chemlali Olive Tree Root Extracts Using LC-ESI-QTOF-MS/MS, Their Cytotoxicity, and Antiviral Assessment

The large quantity of olive roots resulting from a large number of old and unfruitful trees encouraged us to look for ways of adding value to these roots. For this reason, the current research work is devoted to the valorization of olive roots by identifying active phytochemicals and assessing their biological activities, including the cytotoxicity and antiviral potential of different extracts from the Olea europaea Chemlali cultivar. The extract, obtained by ultrasonic extraction, was analyzed using the liquid chromatography-mass spectrometry technique (LC-MS). The cytotoxicity was evaluated through the use of the microculture tetrazolium assay (MTT) against VERO cells. Subsequently, the antiviral activity was determined for HHV-1 (Human Herpesvirus type 1) and CVB3 (Coxsackievirus B3) replication in the infected VERO cells. LC-MS analysis allowed the identification of 40 compounds, classified as secoiridoids (53%), organic acids (13%), iridoids (10%), lignans (8%), caffeoylphenylethanoid (5%), phenylethanoids (5%),sugars and derivatives (2%), phenolic acids (2%), and flavonoids (2%). It was found that extracts were not toxic to the VERO cells. Moreover, the extracts did not influence the appearance of HHV-1 or CVB3 cytopathic effects in the infected VERO cells and failed to decrease the viral infectious titer.

Musa spp. cultivars as a neutralising source against some toxic activities of Bothrops and Crotalus genus snake venoms

Accidents involving snakes from Bothrops spp. and Crotalus spp. constitute the most important cause of envenomation in Brazil and Argentina. Musa spp. (banana) have been reported to be used in popular medicine against snakebite by the members of the Canudos Settlement, located in Goiás. In this way, the aim of this work was to evaluate the antivenom effect of the Ouro (AA), Prata (AAB), Prata-anã (AAB) and Figo (ABB) cultivars against in vitro (phospholipase, coagulation and proteolytic) and in vivo (lethality and toxicity) activities caused by the venoms and toxicity (Artemia salina nauplii and Danio rerio embryos) of Musa spp. as well as the annotation of chemical compounds possibly related to these activities. From the in vitro antiophidic tests with the sap, we observed 100% inhibition of the phospholipase and coagulant activities with the cultivars Prata-anã and Figo against the venoms of B. alternatus and C. d. collineatus, B. diporus and B. pauloensis, respectively, and neutralisation of the lethality against the B. diporus venom. It was observed that the cultivars of Musa spp. did not show toxicity against Artemia salina nauplii and Danio rerio embryos. The sap analysis via HPLC-MS/MS allowed the annotation of the 13 compounds: abscisic acid, shikimic acid, citric acid, quinic acid, afzelechin, Glp-hexose, glucose, sucrose, isorhamnetin-3-O-galactoside-6-raminoside, kaempferol-3-glucoside-3-raminoside, myricetin-3-O-rutinoside, procyanidin B1 and rutin. Therefore, it can be seen that Musa spp. is a potential therapeutic agent that can act to neutralise the effects caused by snakebites.

Antioxidant and antimicrobial characteristics of ethyl acetate polar fractions from walnut green husk

Walnut green husk (WGH) is rich in natural compounds and is valued as a potential source of antioxidant and antimicrobial properties. In this study, the antioxidant and antimicrobial activities of petroleum ether polar fraction, dichloromethane polar fraction, ethyl acetate polar fraction (EAPF), and n-butanol polar fraction from WGH were analyzed. The results showed that EAPF exhibited the highest total flavonoid content (65.74 ± 1.01 mg rutin equivalents [RE]/g dry weight [DW]) and total phenol content (48.73 ± 1.09 mg gallic acid equivalent [GAE]/g DW), with the highest 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical (•OH), and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonate scavenging activity compared with other fractions. EAPF also showed good antibacterial activity against Escherichia coli and Bacillus cereus vegetative cells, with a diameter of inhibition zones of 33.5 and 37.6 mm, respectively, a minimum inhibitory concentration of 31.25 mg/ml and a minimum bactericidal concentration of 62.5 mg/ml, which inhibited the growth of both bacteria. Analysis of the antibacterial mechanism demonstrated that EAPF damaged the integrity of the cell membrane, increased the membrane permeability, and triggered the leakage of intracellular material. In addition, ultrahigh performance liquid chromatography-tandem with mass spectrometry analysis revealed that 8 polyphenols and 14 flavonoids were mainly present in EAPF, such as chlorogenic acid (C₁₆ H₁₈ O₉ ), gallic acid (C₇ H₆ O₅ ), vanillic acid (C₈ H₈ O₄ ), ferulic acid (C₁₀ H₁₀ O₄ ), epicatechin (C₁₅ H₁₄ O₆ ), catechin (C₁₅ H₁₄ O₆ ), hesperetin (C₁₆ H₁₄ O₆ ), naringenin (C₁₅ H₁₂ O₅ ), hyperin (C₂₁ H₂₀ O₁₂ ), luteolin (C1₅ H₁₀ O₆ ), and so on. Therefore, WGH had the potential to be developed as a natural antioxidant and antibacterial material. PRACTICAL APPLICATION: Our work indicates that WGH contains abundant flavonoids and polyphenols compounds. Therefore, the plant byproducts like WGH may have a promising application as a source of antimicrobial and antioxidant additives.

LC-MS Analysis and Antifungal Activity of Turnera subulata Sm

Fungi of the Candida genus are responsible for invasive candidiasis, which affects people all over the world and has high mortality rates. This is due to their virulence factors, which give them great resistance and pathogenicity. In addition, the emergence of multidrug-resistant strains makes it difficult to treat these infections. In this way, natural products have emerged as an alternative to standard drugs, where plants known for their medicinal properties such as Turnera subulata become attractive to research. The present work aimed to analyze the ethanol extract of Turnera subulata leaves against standard strains of Candida albicans, Candida krusei and Candida tropicalis using broth microdilution techniques. The identification of the compounds in T. subulata leaves by LC-MS revealed the presence of a wide variety of substances such as carboxylic acids and terpenes, with flavonoids and fatty acids being more evident. The antifungal assays showed that the extract was not able to inhibit the growth of the tested strains at concentrations with a clinical relevance. However, at higher concentrations, it was able to inhibit the fungal dimorphism of C. albicans and C. tropicalis. It is possible that the T. subulata extract has potential as an inhibitor of fungal virulence factors without affecting the cell viability. Further research should be carried out in order to assess its inhibitory potential for other fungal virulence factors.

Extraction Systems and Analytical Techniques for Food Phenolic Compounds: A Review

Phenolic compounds are highly valuable food components due to their potential utilisation as natural bioactive and antioxidant molecules for the food, cosmetic, chemical, and pharmaceutical industries. For this purpose, the development and optimisation of efficient extraction methods is crucial to obtain phenolic-rich extracts and, for some applications, free of interfering compounds. It should be accompanied with robust analytical tools that enable the standardisation of phenolic-rich extracts for industrial applications. New methodologies based on both novel extraction and/or analysis are also implemented to characterise and elucidate novel chemical structures and to face safety, pharmacology, and toxicity issues related to phenolic compounds at the molecular level. Moreover, in combination with multivariate analysis, the extraction and analysis of phenolic compounds offer tools for plant chemotyping, food traceability and marker selection in omics studies. Therefore, this study reviews extraction techniques applied to recover phenolic compounds from foods and agri-food by-products, including liquid-liquid extraction, solid-liquid extraction assisted by intensification technologies, solid-phase extraction, and combined methods. It also provides an overview of the characterisation techniques, including UV-Vis, infra-red, nuclear magnetic resonance, mass spectrometry and others used in minor applications such as Raman spectroscopy and ion mobility spectrometry, coupled or not to chromatography. Overall, a wide range of methodologies are now available, which can be applied individually and combined to provide complementary results in the roadmap around the study of phenolic compounds.

Lactucin, a Bitter Sesquiterpene from Cichorium intybus, Inhibits Cancer Cell Proliferation by Downregulating the MAPK and Central Carbon Metabolism Pathway

Lung cancer, especially adenocarcinoma, is the second most occurring and highest fatality-causing cancer worldwide. Many natural anticancer compounds, such as sesquiterpene lactones (SLs), show promising anticancer properties. Herein, we examined Lactucin, an SL from the plant Cichorium intybus, for its cytotoxicity, apoptotic-inducing, cell cycle inhibiting capacity, and associated protein expression. We also constructed a biotinylated Lactucin probe to isolate interacting proteins and identified them. We found that Lactucin stops the proliferation of A549 and H2347 lung adenocarcinoma cell lines while not affecting normal lung cell MRC5. It also significantly inhibits the cell cycle at G0/G1 stage and induces apoptosis. The western blot analysis shows that Lactucin downregulates the MAPK pathway, cyclin, and cyclin-dependent kinases, inhibiting DNA repair while upregulating p53, p21, Bax, PTEN, and downregulation of Bcl-2. An increased p53 in response to DNA damage upregulates p21, Bax, and PTEN. In an activity-based protein profiling (ABPP) analysis of A549 cell's protein lysate using a biotinylated Lactucin probe, we found that Lactucin binds PGM, PKM, and LDHA PDH, four critical enzymes in central carbon metabolism in cancer cells, limiting cancer cells in its growth; thus, Lactucin inhibits cancer cell proliferation by downregulating the MAPK and the Central Carbon Metabolism pathway.

Total Flavonoids from Chimonanthus nitens Oliv. Leaves Ameliorate HFD-Induced NAFLD by Regulating the Gut–Liver Axis in Mice

Non-alcoholic fatty liver disease (NAFLD) is one of the chronic liver diseases with high incidence in the world. This study aimed to investigate whether total flavonoids from Chimonanthus nitens Oliv. leaves (TFC) can ameliorate NAFLD. Herein, a high-fat diet (HFD)-induced NAFLD mice model was established, and TFC was administered orally. The results showed that TFC reduced the body weight and liver index and decreased the serum and hepatic levels of triglyceride (TG) and total cholesterol (TC). TFC significantly reduced the activity of liver functional transaminase. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) decreased by 34.61% and 39.57% in serum and 22.46% and 40.86% in the liver, respectively. TFC regulated the activities of oxidative-stress-related enzymes and upregulated the protein expression of nuclear factor E2-related factor (Nrf2)/heme oxygenase (HO-1) pathway in NAFLD mice, and the activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX) in serum were increased by 89.76% and 141.77%, respectively. In addition, TFC reduced the levels of free fatty acids (FFA), endotoxin (ET), and related inflammatory factors in mouse liver tissue and downregulated the expression of proteins associated with inflammatory pathways. After TFC treatment, the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1β in the liver tissues of NAFLD mice were downregulated by 67.10%, 66.56%, and 61.45%, respectively. Finally, TFC reduced liver fat deposition, oxidative stress, and inflammatory response to repair liver damage and alleviate NAFLD. Further studies showed that TFC regulated the expression of intestinal-barrier-related genes and improved the composition of gut microbiota. Therefore, TFC reduced liver inflammation and restored intestinal homeostasis by regulating the gut–liver axis. Overall, our findings revealed a novel function of TFC as a promising prophylactic for the treatment of NAFLD.

Differential Metabolic Responses of Lettuce Grown in Soil, Substrate and Hydroponic Cultivation Systems under NH4+/NO3- Application

Nitrogen (N) is an essential element for plant growth and development. The application of a balanced and optimal amount of N is required for sustainable plant yield. For this, different N sources and forms are used, that including ammonium (NH4+) and nitrate (NO3-). These are the main sources for N uptake by plants where NH4+/NO3- ratios have a significant effect on the biomass, quality and metabolites composition of lettuce grown in soil, substrate and hydroponic cultivation systems. A limited supply of N resulted in the reduction in the biomass, quality and overall yield of lettuce. Additionally, different types of metabolites were produced with varying concentrations of N sources and can be used as metabolic markers to improve the N use efficiency. To investigate the differential metabolic activity, we planted lettuce with different NH4+/NO3- ratios (100:0, 75:25, 50:50, 25:75 and 0:100%) and a control (no additional N applied) in soil, substrate and hydroponic cultivation systems. The results revealed that the 25% NH4+/75% NO3- ratio increased the relative chlorophyll contents as well as the biomass of lettuce in all cultivation systems. However, lettuce grown in the hydroponic cultivation system showed the best results. The concentration of essential amino acids including alanine, valine, leucine, lysine, proline and serine increased in soil and hydroponically grown lettuce treated with the 25% NH4+/75% NO3- ratio. The taste and quality-related compounds in lettuce showed maximum relative abundance with the 25% NH4+/75% NO3- ratio, except ascorbate (grown in soil) and lactupicrin (grown in substrate), which showed maximum relative abundance in the 50% NH4+/50% NO3- ratio and control treatments, respectively. Moreover, 1-O-caffeoylglucose, 1,3-dicaffeoylquinic acid, aesculetin and quercetin-3-galactoside were increased by the application of the 100% NH4+/0% NO3- ratio in soil-grown lettuce. The 25% NH4+/75% NO3- ratio was more suitable in the hydroponic cultivation system to obtain increased lettuce biomass. The metabolic profiling of lettuce showed different behaviors when applying different NH4+/NO3- ratios. Therefore, the majority of the parameters were largely influenced by the 25% NH4+/75% NO3- ratio, which resulted in the hyper-accumulation of health-promoting compounds in lettuce. In conclusion, the optimal N applications improve the quality of lettuce grown in soil, substrate and hydroponic cultivation systems which ultimately boost the nutritional value of lettuce.

HPLC-DAD-ESI/MS profiles of bioactive compounds, antioxidant and anticholinesterase activities of Ephedra alata subsp. alenda growing in Algeria

Ephedra (Ephedraceae) is used in medicine for various purposes as having, antioxidant, anticarcinogen, antibacterial, anti-inflammatory hepatoprotective, anti-obesity, antiviral and diuretic activities. In this study the aim was to investigate chemical constituents of Ephedra alata and understand the possible effects of those constituents in antioxidant activity and alzheimer's disease essay. For this purpose, natural compounds from E.alata were characterized by LC-DAD-ESI-MS/MS using negative and positive ionization modes, while the bioactivity was assessed by acetylcholinesterase (AChE) inhibition study and determining of antioxidant activity; DPPH radical scavenging and β-carotene bleaching assays were used to assess the antioxidant potential. The proposed method of spectrometry provided tentative identification of 27 compounds including alkaloids and phenolic compounds as flavonoids. The methanolic extract showed high contents of total phenolic and exhibited an important antioxidant potential and demonstrated a potent inhibitory effect against acetylcholinesterase (IC₅₀: 11,25 ± 0,25 µg/mL). The results showed that the plant possesses a therapeutic effect.

Bioactive compounds in lettuce: Highlighting the benefits to human health and impacts of preharvest and postharvest practices

Lettuce is one of the most commonly consumed leafy vegetables worldwide and is available throughout the entire year. Lettuce is also a significant source of natural phytochemicals. These compounds, including glycosylated flavonoids, phenolic acids, carotenoids, the vitamin B groups, ascorbic acid, tocopherols, and sesquiterpene lactones, are essential nutritional bioactive compounds. This review aims to provide a comprehensive understanding of the composition of health-promoting compounds in different types of lettuce, the potential health benefits of lettuce in reducing the risks of chronic diseases, and the effect of preharvest and postharvest practices on the biosynthesis and accumulation of health-promoting compounds in lettuce.

Comparative Analysis of Major Flavonoids among Parts of Lactuca indica during Different Growth Periods

L. indica L. cv. Mengzao, a medicinal plant of the Ixeris genus, is rich in flavonoids. In order to thoroughly analyze the the distribution and dynamic change of major flavonoids in its various parts from different growth periods, the flavonoids extracted from L. indica L. cv. Mengzao were identified and quantitatively analyzed by ultra-high-performance liquid chromatography mass spectrometer (LC-MS/MS). Results indicated that 15 flavonoids were identified from L. indica L. cv. Mengzao, and rutin, luteolin, luteolin-7-O-glucoside, kaempferol, quercetin, and apigenin are the major flavonoids in L. indica L. cv. Mengzao. In general, the total flavonoids' content in different parts of L. indica L. cv. Mengzao followed the order flowers > leaves > stems > roots. Flowers and leaves are the main harvesting parts of L. indica L. cv. Mengzao, and the flowering period is the most suitable harvesting period. This study provides valuable information for the development and utilization of L. indica L. cv. Mengzao and determined the best part to harvest and the optimal time for harvesting.

Hyphenated LC-ABTS•+ and LC-DAD-HRMS for simultaneous analysis and identification of antioxidant compounds in Astragalus emarginatus Labill. extracts

The compounds in leaf and stem extracts of Astragalus emarginatus Labill. (AEL), a plant species used in traditional Lebanese medicine, were investigated for antioxidant properties. First, the activity of various extracts was assessed using the Trolox equivalent antioxidant capacity, oxygen radical absorption capacity, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate assays. The extract obtained using 30% ethanol showed the greatest activity. The antioxidant compounds in this extract were screened using a hyphenated high-performance liquid chromatography-2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) radical (ABTS^·+) system before being separated by ultra-high-performance liquid chromatography and identified using high-resolution mass spectrometry and ultra-violet-visible diode array detection. Approximately 40 compounds were identified. Hydroxycinnamates (caffeic, ferulic, and p-coumaric acid derivatives) and flavonoids (quercetin, luteolin, apigenin, and isorhamnetin derivatives) were the two main categories of the identified compounds. The active compounds were identified as caffeic acid derivatives and quercetin glycosides. In addition, the catechol moiety was shown to be key to antioxidant activity. This study showed that AEL is a source of natural antioxidants, which may explain its medicinal use.

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Antioxidant activity of 30% ethanol extract from Astragalus emarginatus Labill was shown by an on-line HPLC-ABTS ^•+ assay.

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Caffeic acid derivatives and quercetin glycosides were responsible for antioxidant activity.

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Approximately forty compounds were tentatively identified using UHPLC-DAD-HRMS.

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Structure-activity investigations showed that the catechol moiety is central to the detected antioxidant activity.

Assessment of Cota altissima (L.) J. Gay for phytochemical composition and antioxidant, anti-inflammatory, antidiabetic and antimicrobial activities

Phytochemical profiles of essential oil (EO), fatty acids, and n-hexane (CAH), diethyl ether (CAD), ethyl acetate (CAE) and methanol extracts (CAM) of Cota altissima L. J. Gay (syn. Anthemis altissima L.) were investigated as well as their antioxidant, anti-inflammatory, antidiabetic and antimicrobial activites. The essential oil was characterized by the content of acetophenone (35.8%) and β-caryophyllene (10.3%) by GC-MS/FID. Linoleic and oleic acid were found as main fatty acids. The major constituents of the extracts were found to be 5-caffeoylquinic acid, 3,5-dicaffeoylquinic acid, isorhamnetin glucoside, quercetin and quercetin glucoside by LC-MS/MS. Antioxidant activities of the extracts were determined by scavenging of DPPH and ABTS free radicals. Also, the inhibitory effects on lipoxygenase and α-glucosidase enzymes were determined. Antimicrobial activity was evaluated against Gram positive, Gram negative bacteria and yeast pathogens. CAM showed the highest antioxidant activity against DPPH and ABTS radicals with IC₅₀ values of 126.60 and 144.40 μg/mL, respectively. In the anti-inflammatory activity, CAE demonstrated the highest antilipoxygenase activity with an IC₅₀ value of 105.40 μg/mL, whereas, CAD showed the best inhibition of α-glucosidase with an IC₅₀ value of 396.40 μg/mL in the antidiabetic activity. CAH was effective against Staphylococcus aureus at MIC = 312.5 µg/mL. This is the first report on antidiabetic, anti-inflammatory and antimicrobial activities of different extracts of C. altissima.

The Combination of Mild Salinity Conditions and Exogenously Applied Phenolics Modulates Functional Traits in Lettuce

The quest for sustainable strategies aimed at increasing the bioactive properties of plant-based foods has grown quickly. In this work, we investigated the impact of exogenously applied phenolics, i.e., chlorogenic acid (CGA), hesperidin (HES), and their combinations (HES + CGA), on Lactuca sativa L. grown under normal- and mild-salinity conditions. To this aim, the phenolic profile, antioxidant properties, and enzyme inhibitory activity were determined. The untargeted metabolomics profiling revealed that lettuce treated with CGA under non-stressed conditions exhibited the highest total phenolic content (35.98 mg Eq./g). Lettuce samples grown under salt stress showed lower phenolic contents, except for lettuce treated with HES or HES + CGA, when comparing the same treatment between the two conditions. Furthermore, the antioxidant capacity was investigated through DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,20-azinobis-(3-ethylbenzothiazoline-6-sulfonate)), and FRAP (ferric reducing antioxidant power) assays, coupled with metal-chelating activity and phosphomolybdenum capacity. An exciting increase in radical scavenging capacity was observed in lettuce treated with exogenous phenolics, in both stress and non-stress conditions. The inhibitory activity of the samples was evaluated against target health-related enzymes, namely cholinesterases (acetylcholinesterase; AChE; butyryl cholinesterase; BChE), tyrosinase, α-amylase, and α-glucosidase. Lettuce treated with HES + CGA under non-stress conditions exhibited the strongest inhibition against AChE and BChE, while the same treatment under salinity conditions resulted in the highest inhibition capacity against α-amylase. Additionally, CGA under non-stress conditions exhibited the best inhibitory effect against tyrosinase. All the functional traits investigated were significantly modulated by exogenous phenolics, salinity, and their combination. In more detail, flavonoids, lignans, and stilbenes were the most affected phenolics, whereas glycosidase enzymes and tyrosinase activity were the most affected among enzyme assays. In conclusion, the exogenous application of phenolics to lettuce represents an effective and green strategy to effectively modulate the phenolic profile, antioxidant activity, and enzyme inhibitory effects in lettuce, deserving future application to produce functional plant-based foods in a sustainable way.

Caffeic acid derivatives (CAFDs) as inhibitors of SARS-CoV-2: CAFDs-based functional foods as a potential alternative approach to combat COVID-19

BACKGROUND

SARS-CoV-2, an emerging strain of coronavirus, has affected millions of people from all the continents of world and received worldwide attention. This emerging health crisis calls for the urgent development of specific therapeutics against COVID-19 to potentially reduce the burden of this emerging pandemic.

PURPOSE

This study aims to evaluate the anti-viral efficacy of natural bioactive entities against COVID-19 via molecular docking and molecular dynamics simulation.

METHODS

A library of 27 caffeic-acid derivatives was screened against 5 proteins of SARS-CoV-2 by using Molegro Virtual Docker 7 to obtain the binding energies and interactions between compounds and SARS-CoV-2 proteins. ADME properties and toxicity profiles were investigated via www.swissadme.ch web tools and Toxtree respectively. Molecular dynamics simulation was performed to determine the stability of the lead-protein interactions.

RESULTS

Our obtained results has uncovered khainaoside C, 6-O-Caffeoylarbutin, khainaoside B, khainaoside C and vitexfolin A as potent modulators of COVID-19 possessing more binding energies than nelfinavir against COVID-19 M^pro, Nsp15, SARS-CoV-2 spike S2 subunit, spike open state and closed state structure respectively. While Calceolarioside B was identified as pan inhibitor, showing strong molecular interactions with all proteins except SARS-CoV-2 spike glycoprotein closed state. The results are supported by 20 ns molecular dynamics simulations of the best complexes.

CONCLUSION

This study will hopefully pave a way for development of phytonutrients-based antiviral therapeutic for treatment or prevention of COVID-19 and further studies are recommended to evaluate the antiviral effects of these phytochemicals against SARS-CoV-2 in in vitro and in vivo models.

Stem Lettuce and Its Metabolites: Does the Variety Make Any Difference?

The objective of the present study was to characterize chemical composition of hitherto unexamined aerial parts of Lactuca sativa var. angustana cv. Grüner Stern. In contrast to leafy and head varieties of the lettuces, asparagus lettuce grown in Europe is much less studied. Fractionation of a methanolic extract from leaves of L. sativa cv. Grüner Stern, supported with HPLC/DAD and 1H NMR analysis, led to the isolation and/or identification of numerous terpenoid and phenolic compounds, including five apocarotenoids-(-)-loliolide, (+)-dehydrovomifoliol, blumenol A, (6S,9S)-vomifoliol, and corchoionoside C; three sesquiterpene lactones; two lignans-((+)-syringaresinol and its 4-O-β-glucoside); five caffeic acid derivatives; and three flavonoids. Some of the compounds, to the best of our knowledge, have never been isolated from L. sativa before. Moreover, monolignols, phenolic acids and a tryptophan-derived alkaloid were found in the analyzed plant material. Stems, leaves and shoot tips of the asparagus lettuce were examined to assess their phenolics and sesquiterpene lactone content as well as DPPH scavenging activity. Another stem lettuce-L. sativa var. angustana cv. Karola, two cultivars of leafy lettuces and one species of wild lettuce-L. serriola, were also examined as a reference material using HPLC/DAD. The results have been discussed regarding our previous studies and the literature data available.

UPLC-qTOF-MS Phytochemical Profile and Antiulcer Potential of Cyperus conglomeratus Rottb. Alcoholic Extract

Cyperus has been commonly used as a multi-use medicinal plant in folk medicine worldwide. The objectives of our study were to determine the different metabolites in the Cyperus conglomeratus Rottb. methanol extract, and to assess its in vivo gastroprotective effect in ethanol-induced gastric ulcer model in rats. Serum levels of galactin-3 and TNF-α were employed as biochemical markers. To pinpoint for active agents, comprehensive metabolites profiling of extract via UPLC-qTOF-MS/MS was employed. A total of 77 chromatographic peaks were detected, of which 70 were annotated. The detected metabolites were categorized into phenolic acids and their derivatives, flavonoids, stilbenes, aurones, quinones, terpenes, and steroids. Rats were divided into six groups; healthy control, ulcer control, standard drug group, and 25, 50, 100 mg/kg of C. conglomeratus treated rats. Pre-treatment with C. conglomeratus alcohol extract significantly reduced galactin-3, and TNF-α in ethanol-induced ulcer model at 25, 50, and 100 mg/kg. Further histopathological and histochemical studies revealed moderate erosion of superficial epithelium, few infiltrated inflammatory cells, and depletion of gastric tissue glycoprotein in the ulcer group. Treatment with the extract protected the gastric epithelial cells in a dose-dependent manner. It could be concluded that C. conglomeratus extract provides significant gastroprotective activity in ethanol-induced gastric ulcer and ought to be included in nutraceuticals in the future for ulcer treatment.

Comparative metabolomics of Phialemonium curvatum as an omnipotent fungus cultivated on crude palm oil versus glucose

BACKGROUND

Sugars and triglycerides are common carbon sources for microorganisms. Nonetheless, a systematic comparative interpretation of metabolic changes upon vegetable oil or glucose as sole carbon source is still lacking. Selected fungi that can grow in acidic mineral salt media (MSM) with vegetable oil had been identified recently. Hence, this study aimed to investigate the overall metabolite changes of an omnipotent fungus and to reveal changes at central carbon metabolism corresponding to both carbon sources.

RESULTS

Targeted and non-targeted metabolomics for both polar and semi-polar metabolites of Phialemonium curvatum AWO2 (DSM 23903) cultivated in MSM with palm oil (MSM-P) or glucose (MSM-G) as carbon sources were obtained. Targeted metabolomics on central carbon metabolism of tricarboxylic acid (TCA) cycle and glyoxylate cycle were analysed using LC-MS/MS-TripleQ and GC-MS, while untargeted metabolite profiling was performed using LC-MS/MS-QTOF followed by multivariate analysis. Targeted metabolomics analysis showed that glyoxylate pathway and TCA cycle were recruited at central carbon metabolism for triglyceride and glucose catabolism, respectively. Significant differences in organic acids concentration of about 4- to 8-fold were observed for citric acid, succinic acid, malic acid, and oxaloacetic acid. Correlation of organic acids concentration and key enzymes involved in the central carbon metabolism was further determined by enzymatic assays. On the other hand, the untargeted profiling revealed seven metabolites undergoing significant changes between MSM-P and MSM-G cultures.

CONCLUSIONS

Overall, this study has provided insights on the understanding on the effect of triglycerides and sugar as carbon source in fungi global metabolic pathway, which might become important for future optimization of carbon flux engineering in fungi to improve organic acids production when vegetable oil is applied as the sole carbon source.

Biomarkers of intake for tropical fruits

Consumption of fruit and vegetable is a key component of a healthy and sustainable diet. However, their accurate dietary assessment remains a challenge. Due to errors in self-reporting methods, the available dietary information is usually biased. Biomarkers of intake constitute objective tools to better reflect the usual or recent consumption of different foods, including fruits and vegetables. Partners of The Food Biomarker Alliance (FoodBall) Project have undertaken the task of reviewing the available literature on putative biomarkers of tropical fruit intake. The identified candidate biomarkers were subject to validation evaluation using eight biological and chemical criteria. This publication presents the current knowledge on intake biomarkers for 17 tropical fruits including banana, mango, and avocado as the most widely consumed ones. Candidate biomarkers were found only for banana, avocado, and watermelon. An array of banana-derived metabolites has been reported in human biofluids, among which 5-hydroxyindole-acetic acid, dopamine sulfate, methoxyeugenol glucuronide, salsolinol sulfate, 6-hydroxy-1-methyl-1,2,3,4-tetrahydro-β-carboline-sulfate, and other catecholamine metabolites. Their validation is still at an early stage, with insufficient data on dose-response relationship. Perseitol and mannoheptulose have recently been reported as candidate biomarkers for avocado intake, while the amino acid citrulline has been associated with watermelon intake. Additionally, the examination of food composition data revealed some highly specific phytochemicals, which metabolites after absorption may be further studied as putative BFI for one or several tropical fruits. To make the field move forward, untargeted metabolomics, as a data-driven explorative approach, will have to be applied in both intervention and observational studies to discover putative BFIs, while their full validation and the establishment of dose-response calibration curves will require quantification methods at a later stage.

Effect of Elicitation on Polyphenol and Carotenoid Metabolism in Butterhead Lettuce (Lactuca sativa var. capitata)

The effect of elicitation in butterhead lettuce on carotenoid and polyphenol metabolism was evaluated. Different concentrations of arachidonic acid (AA), salicylic acid (SA), methyl jasmonate (MJ) (15, 45, and 90 μM) and Harpin protein (HP) (30, 60, and 120 mg/L) were applied on red and green butterhead lettuces. Total phenolic and flavonoid content were incremented by MJ (90 μM) in green and red lettuce. Carotenoids were increased in red lettuce (AA; 45 μM). Green lettuce modifies their phenolic acid profile after elicitation with AA and MJ; meanwhile, red lettuce incremented mainly in hydroxycinnamic acids and flavonols, MJ being the elicitor with the highest effect. There was an impact on secondary metabolite enzyme gene transcript concentration. Phenylalanine ammonia-lyase (PAL) and lycopene beta cyclase (LBC) increased in both varieties after elicitation. A relationship between phytochemical increase and the activation of the metabolic pathways after elicitation in butterhead lettuce was observed.

Characterization of metabolite profiles of white and green spears of asparagus officinalis L. from Caoxian, East China

China is the largest planting country of asparagus (Asparagus officinalis L.) in the world. Caoxian, as the famous asparagus township in China, enjoys a reputation for producing asparagus with high yield and good quality, due to its unique geological characteristic. In this study, a method of reverse-phase ultraperformance liquid chromatography coupled with electrospray tandem mass spectrometry (RP-UPLC-ESI-MS/MS) was established for profiling metabolites from three segments (tip, mid, and base) of 'Caoxian white and green Asparagus'. A total of 114 metabolites were identified, among them, 43 were found for the first time in this vegetable. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) was applied to provide an overview of the metabolite profiles of Caoxian asparagus and to separate different segments of spears. The variables most decisive to discriminate among segments included 9 of the metabolites tentatively identified. This study will help to improve the protection of Caoxian asparagus geographical indication.

Identification and quantification of selected metabolites in differently pigmented leaves of lettuce (Lactuca sativa L.) cultivars harvested at mature and bolting stages

BACKGROUND

Identification and screening of cultivars rich in bioactive phytoconstituents can be potentially useful to make nutrient-dense dishes and in medicinal formulations. In this study, we have identified, characterized and quantified caffeoylquinic acids, dicaffeoylquinic acid, dicaffeoyltartaric acid, kaempferol conjugates, quercetin malonylglucoside, sesquiterpene lactones, and cyanidin in 22 lettuce cultivars at mature and bolting stages using UPLC-PDA-Q-TOF-HDMS, UPLC, and HPLC.

RESULTS

The composition and contents of the studied metabolites and antioxidant activity varied significantly and depend on leaf color, cultivar type and stage of maturity. The main phenolic acid components of lettuce were quinic and tartaric acid derivatives, whereas kaempferol derivatives were the dominant flavonoids. The sum of the content of phenolic acids ranged from 18.3 to 54.6 mg/100 g DW and 15.5 to 54.6 mg/100 g DW, whereas the sum of the contents of flavonoids ranged from 9.2 to 25.9 mg/100 g DW and 14.9 to 83.0 mg/100 g DW in mature and bolting stage cultivars, respectively. The content of cyanidin, lactucin, lactucopicrin, and ABTS radical antioxidant activity were in the range of 0.3 to 9.7 (mature stage) and 0.5 to 10.2 mg/g DW (bolting stage), 1.8 to 41.9 (mature stage) and 9.7 to 213.0 (bolting stage) µg/g DW, 9.9 to 344.8 (mature stage) and 169.2 to 3888.2 (bolting stage) µg/g DW, and 12.1 to 29.0 (mature stage) and 15.7 to 30.3 (bolting stage) mg TE/g DW, respectively. The principal component analysis (PCA) showed that the green and red pigmented lettuce cultivars were grouped to the negative and positive sides of PC1, respectively, while the green/red pigmented cultivars were distributed throughout the four quadrants of the PCA plots with no prominent grouping. The loading plot showed that phenolic acids, flavonoids, and cyanidin are the most potent contributors to the radical scavenging activity of lettuce extracts.

CONCLUSIONS

Lettuce at the bolting stage accumulate relatively high amount of sesquiterpene lactones (SLs), quercetin malonylglucoside (QMG), methylkaempferol glucuronide (MKGR), kaempferol malonylglucoside (KMG), and 3-O-caffeoylquinic acid (3-CQA) compared to the mature stage. Higher amount of phytoconstituents were found to be accumulated in the red pigmented lettuce leaves compared to the green lettuce leaves. In addition, the contents of most of the metabolites in lettuce seem to increase with age of the leaves. The presence of the two bitter SLs, lactucin and lactucopicrin, in significantly high amount in lettuce leaves at bolting stage could diminish consumer acceptance. However, alternatively, these leaves could be utilized by nutraceutical companies working to recover these compounds.

Silencing of germacrene A synthase genes reduces guaianolide oxalate content in Cichorium intybus L

Chicory (Cichorium intybus L.) is a medicinal and industrial plant from the Asteraceae family that produces a variety of sesquiterpene lactones (STLs), most importantly bitter guaianolides: lactucin, lactucopicrin and 8-deoxylactucin as well as their modified forms such as oxalates. These compounds have medicinal properties; however, they also hamper the extraction of inulin - a very important food industry product from chicory roots. The first step in guaianolide biosynthesis is catalyzed by germacrene A synthase (GAS) which in chicory exists in two isoforms - GAS long (encoded by CiGASlo) and GAS short (encoded by CiGASsh). AmiRNA silencing was used to obtain plants with reduced GAS gene expression and level of downstream metabolites, guaianolide-15-oxalates, as the major STLs in chicory. This approach could be beneficial for engineering new chicory varieties with varying STL content, and especially varieties with reduced bitter compounds more suitable for inulin production.

Antioxidant, metabolic enzymes inhibitory ability of Torreya grandis kernels, and phytochemical profiling identified by HPLC-QTOF-MS/MS

In this study, the antioxidant activities, α-glucosidase and tyrosinase inhibitory ability of Torreya grandis kernels (TGK) were performed. Samples were extracted with various polarity of ethanol, and the major phytochemical profile was characterized. The results showed that 70% of ethanol extract gave the richest phenolics and flavonoids. The strongest DPPH· and ABTS·⁺ scavenging ability, as well as the best inhibition on tyrosinase and α-glucosidase was also detected on 70% of ethanol extract. Among the fractions of 70% of ethanol extract, the ethyl acetate fraction (EAF) owned the highest phenolics, flavonoids, and the best DPPH· and ABTS·⁺ scavenging ability, and tyrosinase inhibition. Unexpectedly, the dichloromethane fraction possessed the strongest inhibition on α-glucosidase, which was much greater than that of acarbose. HPLC-QTOF-MS/MS analysis result to the characterization of 19 compounds from EAF. The results implied that TGK can be a potential source of natural antioxidants, α-glucosidase and tyrosinase inhibitors. Practical applications The kernels of T. grandis are one of the precious nuts in the world, and the extracts were advertised to show a variety of biological activities and pharmacological effects. However, researches on the phytochemical constituents and bioactivities are fewer. In this study, TGK was found to show good potency in antioxidant, α-glucosidase and tyrosinase inhibitory activities. The 70% ethanol is the best solvent for extracting above mentioned active components, and ethyl acetate can be the suitable enriching solvent. In addition, the predominant phytochemical compounds in EAF were characterized. Therefore, this research can help to the performance of further research and application of TGK in functional products.

Targeted Metabolomics Analysis and Identification of Biomarkers for Predicting Browning of Fresh-Cut Lettuce

The metabolism of phenolic compounds is a key factor in the development of wound-induced enzymatic browning of fresh-cut lettuce. In the present study, the lettuce midribs discriminant metabolites, selected in a previous untargeted metabolomics study, were thoroughly identified. Our results showed that their basal contents correlated with browning developed after 5 days of storage. 5- trans-Chlorogenic acid and 5- cis-chlorogenic acid were positively correlated with browning, while sinapaldehyde and its 4-β-d-glucoside and 4-(6'-malonyl)-β-d-glucoside conjugates were negatively correlated. Using targeted metabolomics, the metabolites were analyzed in lettuce heads with different degrees of development and different browning susceptibility and these biomarkers were confirmed. Despite the large variability in the browning process of lettuce, the chlorogenic acids/sinapaldehyde derivatives ratio showed a linear correlation ( r2 = 0.79) with the fresh-cut lettuce browning developed in 24 Romaine lettuce cultivars, validating the relevance of these biomarkers. These results show that the analysis of the basal content of these metabolites could be used in lettuce breeding programs to select cultivars that are more appropriate for the fresh-cut industry.

The Health Promoting Bioactivities of Lactuca sativa can be Enhanced by Genetic Modulation of Plant Secondary Metabolites

Plant secondary metabolites are protective dietary constituents and rol genes evidently increase the synthesis of these versatile phytochemicals. This study subjected a globally important vegetable, lettuce (Lactuca sativa) to a combination of untargeted metabolomics (LC-QTof-MS) and in vitro bioactivity assays. Specifically, we examined the differences between untransformed cultured lettuce (UnT), lettuce transformed with either rolABC (RA) or rolC (RC) and commercially grown (COM) lettuce. Of the 5333 metabolite features aligned, deconvoluted and quantified 3637, 1792 and 3737 significantly differed in RA, RC and COM, respectively, compared with UnT. In all cases the number of downregulated metabolites exceeded the number increased. In vitro bioactivity assays showed that RA and RC (but not COM) significantly improved the ability of L. sativa to inhibit α-glucosidase, inhibit dipeptidyl peptidase-4 (DPP-4) and stimulate GLP-1 secretion. We putatively identified 76 lettuce metabolites (sesquiterpene lactones, non-phenolic and phenolic compounds) some of which were altered by several thousand percent in RA and RC. Ferulic acid levels increased 3033–9777%, aminooxononanoic acid increased 1141–1803% and 2,3,5,4′tetrahydroxystilbene-2-O-β-d-glucoside increased 40,272–48,008%. Compound activities were confirmed using commercially obtained standards. In conclusion, rol gene transformation significantly alters the metabolome of L.sativa and enhances its antidiabetic properties. There is considerable potential to exploit rol genes to modulate secondary metabolite production for the development of novel functional foods. This investigation serves as a new paradigm whereby genetic manipulation, metabolomic analysis and bioactivity techniques can be combined to enable the discovery of novel natural bioactives and determine the functional significance of plant metabolites.

Biological activity and chemical characterization of Pouteria lucuma seeds: A possible use of an agricultural waste

Pouteria lucuma fruit is widely used to prepare cakes, ice creams and juice or also commercialized as pulp and flour. As result of this business thousands of tons of seeds are generated as an agricultural waste. This study presents the antioxidant and antiulcer activities, and the identification of secondary metabolites by UHPLC/ESI/MS/MS of an agroindustrial waste of Pouteria lucuma seeds. Fifty-nine compounds were tentatively identified including eight aminoacids, five organic acids, one nucleoside, five phenolic acids, five phenolic alcohols, nineteen flavonoids, six lipids, and seven unknowns in the methanol extract of P. lucuma seeds. The total phenolic content of the seeds was 52.82 ± 0.09 μmol GAE/g dry weight, while total flavonoid content was 5.99 ± 0.01 μmol Q/g dry weight. The antioxidant activity was 58.14 ± 0.05, 66.97 ± 0.00, 272.50 ± 0.00, and 67.02 ± 2.23 for the DPPH, ABTS, FRAP, and superoxide anion assays, respectively. The highest gastroprotective activity was obtained at 100 mg/kg (78%), which as higher than the positive control lansoprazole (75%). Our findings showed that P. lucuma seed extracts have moderate to high antioxidant activity and gastroprotective properties. Therefore, it was demostrated that lucuma seeds commonly eliminated as an agricultural industry waste, could be useful for the preparation of nutritional supplements.

A Metabolomics Approach to the Identification of Urinary Biomarkers of Pea Intake

A significant body of evidence demonstrates that isoflavone metabolites are good markers of soy intake, while research is lacking on specific markers of other leguminous sources such as peas. In this context, the objective of our current study was to identify biomarkers of pea intake using an untargeted metabolomics approach. A randomized cross-over acute intervention study was conducted on eleven participants who consumed peas and couscous (control food) in random order. The urine samples were collected in fasting state and postprandially at regular intervals and were further analysed by ultra-performance liquid chromatography coupled to quadrupole time of flight mass spectrometry (UPLC-QTOF-MS). Multivariate statistical analysis resulted in robust Partial least squares Discriminant Analysis (PLS-DA) models obtained for comparison of fasting against the postprandial time points (0 h vs. 4 h, (R²X = 0.41, Q² = 0.4); 0 h vs. 6 h, ((R²X = 0.517, Q² = 0.495)). Variables with variable importance of projection (VIP) scores ≥1.5 obtained from the PLS-DA plot were considered discriminant between the two time points. Repeated measures analysis of variance (ANOVA) was performed to identify features with a significant time effect. Assessment of the time course profile revealed that ten features displayed a differential time course following peas consumption compared to the control food. The interesting features were tentatively identified using accurate mass data and confirmed by tandem mass spectrometry (MS using commercial spectral databases and authentic standards. 2-Isopropylmalic acid, asparaginyl valine and N-carbamoyl-2-amino-2-(4-hydroxyphenyl) acetic acid were identified as markers reflecting pea intake. The three markers also increased in a dose-dependent manner in a randomized intervention study and were further confirmed in an independent intervention study. Overall, key validation criteria were met for the successfully identified pea biomarkers. Future work will examine their use in nutritional epidemiology studies.

Metabolite variation in the lettuce gene pool: towards healthier crop varieties and food

INTRODUCTION

Lettuce (Lactuca sativa L.) is generally not specifically acknowledged for its taste and nutritional value, while its cultivation suffers from limited resistance against several pests and diseases. Such key traits are known to be largely dependent on the ability of varieties to produce specific phytochemicals.

OBJECTIVES

We aimed to identify promising genetic resources for the improvement of phytochemical composition of lettuce varieties.

METHODS

Phytochemical variation was investigated using 150 Lactuca genebank accessions, comprising a core set of the lettuce gene pool, and resulting data were related to available phenotypic information.

RESULTS

A hierarchical cluster analysis of the variation in relative abundance of 2026 phytochemicals, revealed by untargeted metabolic profiling, strongly resembled the known lettuce gene pool structure, indicating that the observed variation was to a large extent genetically determined. Many phytochemicals appeared species-specific, of which several are generally related to traits that are associated with plant health or nutritional value. For a large number of phytochemicals the relative abundance was either positively or negatively correlated with available phenotypic data on resistances against pests and diseases, indicating their potential role in plant resistance. Particularly the more primitive lettuces and the closely related wild relatives showed high levels of (poly)phenols and vitamin C, thus representing potential genetic resources for improving nutritional traits in modern crop types.

CONCLUSION

Our large-scale analysis of phytochemical variation is unprecedented in lettuce and demonstrated the ample availability of suitable genetic resources for the development of improved lettuce varieties with higher nutritional quality and more sustainable production.