Flavonol Compounds Research Articles

Effects of White LED Lighting with Specific Shorter Blue and/or Green Wavelength on the Growth and Quality of Two Lettuce Cultivars in a Vertical Farming System

White (W) light-emitting diode (LED) light has been used as an efficient light source for commercial plant cultivation in vertical farming. This study aimed to examine the effect of W LED light sources on the growth and quality of butterhead and romaine lettuce. Three W LED light sources including normal W light (NWL) which has 450 nm as its pumping wavelength and two specific W lights (SWL1 and SWL2) with shorter blue peak wavelength (437 nm) were used to grow lettuce in comparison to a red (R) and blue (B) LED combination. As a result, SWL1 and SWL2 treatments with the same electrical power or photosynthetic photon flux density (PPFD) resulted in more growth of both lettuce cultivars compared to RB treatment. Some phenolic and flavonol contents were increased in the RB treatment, whereas SWL2 treatment stimulated the accumulation of other phenolic and flavonol compounds. Meanwhile, neither NWL nor SWL1 treatments increased the individual phenolic and flavonol contents in either cultivar (except for some flavonols in romaine lettuce in the SWL1 group). In addition, light and energy use efficiencies were also highest in the SWL1 and SWL2 treatments. These results illustrate the positive effects of specific W LED light on lettuce growth and quality, and suggest that the specific W LED light sources, especially SWL2, could be preferably used in vertical farming.

Functional Analyses of Flavonol Synthase Genes From Camellia sinensis Reveal Their Roles in Anther Development.

Flavonoids, including flavonol derivatives, are the main astringent compounds of tea and are beneficial to human health. Many researches have been conducted to comprehensively identify and characterize the phenolic compounds in the tea plant. However, the biological function of tea flavonoids is not yet understood, especially those accumulated in floral organs. In this study, the metabolic characteristics of phenolic compounds in different developmental stages of flower buds and various parts of the tea flower were investigated by using metabolomic and transcriptomic analyses. Targeted metabolomic analysis revealed varying accumulation patterns of different phenolic polyphenol compounds during flowering; moreover, the content of flavonol compounds gradually increased as the flowers opened. Petals and stamens were the main sites of flavone and flavonol accumulation. Compared with those of fertile flowers, the content of certain flavonols, such as kaempferol derivatives, in anthers of hybrid sterile flowers was significantly low. Transcriptomic analysis revealed different expression patterns of genes in the same gene family in tea flowers. The CsFLSb gene was significantly increased during flowering and was highly expressed in anthers. Compared with fertile flowers, CsFLSb was significantly downregulated in sterile flowers. Further functional verification of the three CsFLS genes indicated that CsFLSb caused an increase in flavonol content in transgenic tobacco flowers and that CsFLSa acted in leaves. Taken together, this study highlighted the metabolic properties of phenolic compounds in tea flowers and determined how the three CsFLS genes have different functions in the vegetative and reproductive organs of tea plants. Furthermore, CsFLSb could regulated flavonol biosynthesis in tea flowers, thus influencing fertility. This research is of great significance for balancing the reproductive growth and vegetative growth of tea plants.

Kaempferol and Kaempferide Attenuate Oleic Acid-Induced Lipid Accumulation and Oxidative Stress in HepG2 Cells.

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases which lacks ideal treatment options. Kaempferol and kaempferide, two natural flavonol compounds isolated from Hippophae rhamnoides L., were reported to exhibit a strong regulatory effect on lipid metabolism, for which the mechanism is largely unknown. In the present study, we investigated the effects of kaempferol and kaempferide on oleic acid (OA)-treated HepG2 cells, a widely used in vitro model of NAFLD. The results indicated an increased accumulation of lipid droplets and triacylglycerol (TG) by OA, which was attenuated by kaempferol and kaempferide (5, 10 and 20 μM). Western blot analysis demonstrated that kaempferol and kaempferide reduced expression of lipogenesis-related proteins, including sterol regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS) and stearoyl-CoA desaturase 1 (SCD-1). Expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT enhancer binding proteins β (C/EBPβ), two adipogenic transcription factors, was also decreased by kaempferol and kaempferide treatment. In addition, western blot analysis also demonstrated that kaempferol and kaempferide reduced expression of heme oxygenase-1 (HO-1) and nuclear transcription factor-erythroid 2-related factor 2 (Nrf2). Molecular docking was performed to identify the direct molecular targets of kaempferol and kaempferide, and their binding to SCD-1, a critical regulator in lipid metabolism, was revealed. Taken together, our findings demonstrate that kaempferol and kaempferide could attenuate OA-induced lipid accumulation and oxidative stress in HepG2 cells, which might benefit the treatment of NAFLD.

Phenolics composition and contents, as the key quality parameters of table grapes, may be influenced obviously and differently in response to short-term high temperature

Although the grape surface appears to be normal under high temperature during the selling period, the nutritional quality of grape might be greatly affected. Phenolics content and composition are key indicators reflective of grape's nutritional quality. Herein, the paper investigated effects of short-term high temperature (40 °C; 2 h) on grape phenolics from five table grape varieties to evaluate grape quality. Twenty-three phenolics were identified and quantified through UHPLC-ESI-qTOF-MS2 and UHPLC-QQQ-MS2, respectively. The results observed that short-term high temperature significantly reduced flavonoids in European and American varieties. In Eurasian varieties, high temperature induced the accumulation of stilbenes and flavonols compounds while lowered other compounds. Myricetin 4′-methylether-3-O-rhamnoside, a differential metabolite responding to high temperature in all table grapes was screened. Combining with the analysis of molecular level, high temperature down-regulated the phenolics biosynthesis-related genes involved in phenolics metabolic pathways (flavonols, stilbenes, anthocyanins and flavan-3-ols metabolic pathways) in grapes except Muscat de Hambourg grapes, such as the expression of VvUFGT, VvANR, VvLAR, VvFLS, VvSTS, VvF3′5′H and VvAOMT. Our findings suggest that short-term high temperature during the selling period is not conducive to consumer expectations, due to the partial loss of grape nutrition quality.

Multiple modes of action of myricetin in influenza A virus infection.

Influenza A virus remains a major threat to public health worldwide after its first pandemic. Scientists keep searching novel anti-influenza drugs, of which natural products present to be an important source. Myricetin, a natural flavonol compound, which exists in many edible plants, which has a wide range of biological activities, but its anti-influenza A virus activity is ambiguous. This study aims to evaluate the anti-influenza activity of myricetin and elucidate its underlying mechanism. Our results demonstrated that myricetin could significantly inhibit influenza A virus replication, reduce viral polymerase activity via selective inhibition of viral PB2 subunit, and the production of inflammatory cytokines by inhibiting TLR3 signaling pathway. The binding affinity analysis and the result of molecular docking revealed that myricetin interacted with the PB2 cap-binding pocket of influenza A virus. The above results suggested myricetin could exhibit anti-influenza virus activity with low cytotoxicity as well, and myricetin had low toxicity in BALB/c mice in vivo. Results from this study highlighted myricetin could be considered as a promising anti-influenza virus agent with dual inhibition profile. Furthermore, the compound with similar structure would provide a new option for the development of novel inhibitors against influenza A virus.

Wild pink bayberry fruit: the effect of in vitro gastrointestinal digestion on phytochemical profiles, and antioxidant and antiproliferative activities.

The regular consumption of polyphenol-rich foods is essential to prevent the onset of diseases. Wild fruits are known to possess higher levels of bioactive components than the domesticated fruits because of the severe environmental conditions they are grown in. The aim of this study was to evaluate the phytochemical profiles, and antioxidant and antiproliferative activities of a wild pink bayberry fruit after in vitro digestion and to compare them with results obtained with a chemical extraction method. A low release of total phenolics and anthocyanins was observed after digestion compared with chemical extraction, while more flavonol contents were found by HPLC analysis. The digesta samples demonstrated low levels of extracellular antioxidant activity (EAA) and cellular antioxidant activity (CAA). However, the cellular uptake rate was increased during the in vitro digestion, and the largest value of 75.35% was obtained in the colon step. Notably, the antiproliferative activity in the colon digesta (10.14 ± 0.13 mg mL-1) was close to that of extracts (7.6 ± 0.63 mg mL-1). Pearson correlation analysis revealed that EAA and CAA were significantly correlated with TPC, while the antiproliferative activity was significantly correlated with the total contents of three flavonol compounds (quercetin, kaempferol, and myricetin). Our observations provide new insights into the bioactivity variation of whole fruits as affected by simulated digestion.

Gastric floating pill enhances the bioavailability and drug efficacy of dihydromyricetin in vivo

Dihydromyricetin (DHM) is a natural flavonol compound that has shown significant pharmacological activities such as anti-atherosclerosis, anti-diabetes, anti-oxidation, and anti-inflammation, but its clinical application has been hindered by its poor stability and rapid metabolism that reduced its bioavailability in vivo. Since DHM is more stable under acidic conditions, selective and sustained absorption of DHM in the stomach via gastric floating drug carriers provide an attractive way to settle the problems. Previously, we reported a gastric floating tablet for DHM that demonstrated improved stability and bioavailability of the drug. However, the application of this drug carrier was still constrained by low drug content percentage, and short floating and drug releasing durations. Besides, the influences of dosage forms on the drug efficacy of DHM in vivo were not yet clear. In this study, gastric floating pill as a novel sustained-release dosage form for DHM (DHM-GFP) was developed using combined techniques of extrusion molding and freeze drying. The physicochemical properties of DHM-GFP could well meet the pharmacopoeial requirements for pills. Our data indicated that DHM-GFP had significantly higher drug content percentage, improved floating ability and more sustained drug release than the previously reported DHM tablet, and is promising to become a once-a-day dosing preparation. More importantly, this novel dosage form resulted in notably prolonged residence time, improved bioavailability, and enhanced anti-inflammatory effect of DHM in vivo, indicating its great potential to translate this natural compound into clinical application.

Comparison of phenolics, antioxidant capacity and total phenol bioaccessibility of Ribes spp. grown in Turkey

In this study, anthocyanins (13), flavanols (6), phenolic acids (10), flavonol glycosides (17), antioxidant capacity, and bioaccessible phenolic content of Ribes spp., grown in Turkey were investigated. Individual phenolic compounds were identified and quantified with LC-QTOF/MS in red and black currants and hybrid Jostaberry. Significant variations in the individual phenolic compounds could be observed between the different cultivars. In all black currant cultivars, cyanidin 3,5-di-O-glucoside was the predominant anthocyanin compounds (p ≤ 0.01). Cyanidin 3-O-sambubioside and cyanidin 3-O-rutinoside were detected in red currants. In all Ribes cultivars quercetin 3-O-rutinoside was the major flavonol glycoside and epigallocatechin found as the dominant flavonol compound. Rosenthal had the highest amount of total phenols, antioxidant capacity levels by DPPH and CUPRAC. Boskoop Giant characterized with the highest amount of total anthocyanin and bioaccessibility of phenolic compounds (84.27%).

Comparative Analysis Reveals the Metabolic Characteristics of Astringent Seeds of Chinese Fir (Cunninghamia lanceolata (Lamb) Hook) during Astringent Compounds Accumulation Stages

Research Highlights: The present study firstly reported the metabolic dynamics of astringent seed, a special type of abortion in Chinese fir, during the astringent material stages. The results provide a reference for further study on its occurrence mechanism and enrich the understanding of the plant seed developmental physiology. Background and Objectives: Astringent seed is a type of abortive phenomenon in Chinese fir, which significantly reduces the yield and quality of elite seeds for its high-incidence and indistinguishableness in seed orchard. Embryo defects can be observed in the astringent seed, accompanied with rapid accumulation of secondary metabolites. However, types of those metabolites in astringent seed, dynamic changes during seed growth process, and different accumulative characteristics compared to germinable seed have not been explained. Materials and Methods: Astringent and germinable seed samples were collected at four stages aim to determine the differences in their metabolic patterns. A liquid chromatography-mass spectrometry (LC-MS) detection was used to generate the raw metabolic peaks. Bioinformatics statistical strategies were used to further investigation. Results: A total of 421 metabolites were screened and 112 metabolites were identified as the different expressive metabolites including 68 up-regulated and 44 down-regulated metabolites. Those different expressive metabolites were grouped into 26 classes. Flavone, flavonol, and amino acid derivatives compounds were the most varied metabolites. Four subcategories which could represent the diverse basic expressive patterns or accumulative activity in different sample groups were further clustered. Moreover, pathways related to biosynthesis/degradation/metabolism of flavonoid-like compounds, amino acid/nucleotides derivatives, zeatin, and IAA were clearly enriched. Conclusions: Significant metabolic differences were observed across and between astringent and germinable seeds 105 d after pollination. Massive accumulation of flavonoids-like compounds, significant reduction of amino acids/nucleotides and their derivatives, and the abnormal expression of phytohormones, lipids and other secondary metabolites are the main metabolic characteristics in astringent seeds.

Model-free and model-based analysis of thermo-oxidative response of wolfberries: A new developed mechanistic scheme

Thermally accelerated oxidative degradation of wolfberry pulp was kinetically monitored using model-free and model-based approaches. Kinetic calculations were performed based on simultaneous thermal analysis measurements in an air at four different heating rates. From kinetic analysis, new developed mechanistic scheme which is responsible for wolfberries anti-oxidative behavior was proposed. It was found that thermo-oxidative process proceeds through multiplestep mechanism including sum of two independent reaction sets, via consecutive and competitive steps. It was established that rutoside degradation pathway to flavonol through hydrolysis reaction is rate-determining step of considered process. Furthermore, it was found that key flavonol compound degraded by competitive reactions mechanism forming such kinetic branches, which lead to compounds responsible for wolfberries antioxidant activity. It was established that flavonol oxidative cleavage reaction and oxidative polymerization are main chemical routes which are very important in a complex antioxidant mechanism for scavenging free radicals in wolfberries oxidative stress response.

Quercetin promotes in vitro maturation of oocytes from humans and aged mice

Maternal fertility declines irreversibly with aging, and advanced maternal age is mostly related to impaired oocyte quality. The flavonol compound quercetin is considered to be an anti-aging agent due to its cytoprotective actions as an antioxidant. However, its role and mechanisms on aged oocytes are unclear. In this study, the quercetin promotes in vitro maturation (IVM) and early embryonic development of oocytes from aged mice. It is extended these findings in human oocytes, showing that quercetin promotes the IVM rate by 19.6% and increases the blastocyst formation rate by 15.5% compared to untreated controls. The overall oocyte quality of aged mice is improved by quercetin treatment, assessed as spindle/chromosome morphology and cortical granule distribution. Mitochondria is the primary endogenous source of age-related oxidative stress, and an RNA-seq analysis of quercetin-treated oocytes reveals molecular insights including scavenged mitochondrial-ROS, reduced apoptosis, and improved autophagy. Further, this study demonstrates that quercetin reduces ROS via SIRT3-mediated acetylation of SOD2’s K68 residue. Thus, beyond demonstrating that quercetin confers beneficial mitochondria-related impacts in aged oocytes, this study illustrates a potential strategy to prevent or delay oocyte aging and to improve success rates of assisted human reproductive technologies (ART).

Nanoencapsulation of food bioactives in supramolecular assemblies based on cyclodextrins and surfactant

The bioavailability of poorly soluble food ingredients can be achieved by their encapsulation into the 3D macrocyclic structure or self-assembled surfactant micelles. In this study, the mixed self-assembly of cyclodextrins (CDs) and cationic surfactant, 1-hexadecyl-4-(2-(1-methylpyridin-1-ium-4-yl)vinyl)pyridin-1-ium chloride, was studied by a set of physicochemical methods. It was shown using tensiometry and conductometry that the presence of CDs in the micellar medium of this surfactant increases the critical aggregation concentration. Moreover, NMR spectroscopy and spectrophotometry revealed the interaction between the alkyl tail of surfactant and the internal cavity of CDs. It is interesting to note that in the case of γ-CD and HP-β-CD there was additional binding by the vinyl group of surfactant. The observed patterns of aggregation behavior were confirmed by the method of solubilization of hydrophobic substances. Spectrophotometric monitoring of the solubilization of hydrophobic flavonoids (rutin and quercetin) demonstrated that mixed assemblies enriched with surfactant are capable of binding the flavonoid, while they show poor binding ability towards flavonol compound in the presence of a small amount of surfactant.. Variation of the component ratio in the supramolecular CD–surfactant system also allows adjusting the biological properties. Systems with an excess of CD are less toxic to the cells of test microorganisms, herewith, an increase of the surfactant content in a mixture with CD leads to an increase in both antimicrobial and hemolytic activities. Therefore, when using CD complex-based supramolecular approach for food safety, it is necessary to take into account the toxic properties of the base components of the supramolecular mixture.

Особливості метаболізму сосни звичайної в осередках усихання у Київському Поліссі

За умов глобальної зміни клімату зростає актуальність досліджень, спрямованих на підвищення продуктивності і біологічної стійкості лісів. Особливо увагу привертають дослідження сосни звичайної (Pinus sylvestris L.), яка займає широкий ареал і характеризується складною внутрішньовидовою структурою. Одним із чинників абіотичного стресу для сосни звичайної є спалахи масового розмноження стовбурових комах-шкідників. Рослини, які періодично перебувають під впливом стресу, вимушені адаптуватися до нього шляхом фізіолого-біохімічної та анатомо-морфологічної перебудови. Отже, важливим аспектом формування стійких до стрес-чинників, зокрема до нападу комах, соснових деревостанів є біохімічна індикація стану дерев, для якої використовують продукти основного обміну та вторинні метаболіти. У Київському Поліссі в осередку "короїдного" усихання досліджено морфологічні параметри хвої, а також вміст водорозчинних білків і низькомолекулярних сполук фенольної природи (флавонолів – у хвої; катехінів, проантоціанідинів – у хвої та лубі) у деревах сосни звичайної (Pinus sylvestris L.). Вміст білків і фенольних сполук визначали колориметричним методом за загальноприйнятими методиками. Встановлено відмінності вмісту сполук фенольної природи у лубі та хвої сосни звичайної. Вміст розчинних білків у хвої є істотно більшим, ніж у лубі, тоді як сполуки фенольної природи (проантоціанідини, катехіни) інтенсивніше накопичуються у лубі. Мінливість білкового синтезу, як у лубі, так і у хвої, є низькою. Сполуки флавоноли зафіксовані тільки у хвої. Не встановлено істотних залежностей між вмістом сполук фенольної природи і таксаційними показниками дерев сосни звичайної. На тлі масового всихання сосни звичайної в Київському Поліссі серед ослаблих дерев для більш стійких екземплярів характерна висока активність білків, що залучені до синтезу вторинних метаболітів, які чинять позитивний вплив на стійкість рослин в умовах дії стресорів.

Metabolic and transcriptomic analysis related to flavonoid biosynthesis during the color formation of Michelia crassipes tepal

Michelia crassipes is the only plant with purple flowers amongst Michelia species, and its tepals exhibit an obvious color change from green to purple. In this study, a combination of metabolic and transcriptomic analyses was conducted at three stages of tepals in Michelia crassipes: green tepal, purple spot-containing tepal, and totally purple tepal. Several classes of flavonoid compounds were detected and cyanidin 3-rutinoside and delphinidin 3-glucoside were the major anthocyanins underlying the purple color formation, along with co-pigmentation of flavone compounds represented by luteolin derivatives and flavonol compounds represented by kaempferol and quercetin derivatives. Transcriptome analysis revealed up-regulation of genes encoding enzymes involved in the conversion of phenylpropanoid for flavonoid biosynthesis in Stage 1 vs. Stage 2, whereas up-regulation of most flavonoid biosynthesis genes was observed in Stage 1 vs. Stage 3. MYB, bHLH, and WD40 isoforms, as well as other classes of transcriptional factors, also exhibited differential expression. In addition, differentially expressed genes putatively related to the transport of flavonoids were also identified. The results of the current study provide insight into the regulatory mechanism underlying the color transition from green to purple in Michelia crassipes tepals and describe a complicated network involving PAL, transporter genes, and transcription factors, specifically responsible for the emergence of purple color in Stage 1 vs. Stage 2.

Transcriptomic Analysis of Root Restriction Effects on Phenolic Metabolites during Grape Berry Development and Ripening

In the present study, the effects of root restriction (RR) on the main phenolic metabolites and the related gene expression at different developmental stages were studied at the transcriptomic and metabolomic levels in "Summer Black" grape berries (Vitis vinifera × Vitis labrusca). The results were as follows: seven phenolic acid compounds, three stilbene compounds, nine flavonol compounds, 10 anthocyanin compounds, and 24 proanthocyanidin compounds were identified by ultra-performance liquid chromatography-high-resolution mass spectrometry. RR treatment significantly promoted the biosynthesis of phenolic acid, trans-resveratrol, flavonol, and anthocyanin and also affected the proanthocyanidin content, which was elevated in the early developmental stages and then reduced in the late developmental stages. The functional genes for phenylalanine ammonia-lyase, trans-cinnamate 4-monooxygenase, 4-coumarate-CoA ligase, shikimate O-hydroxycinnamoyl transferase, chalcone synthase, chalcone isomerase, stilbene synthase, flavonoid 3',5'-hydroxylase, anthocyanidin 3-O-glucosyltransferase, and the transcription factors MYBA1, MYBA2, MYBA3, and MYBA22 were inferred to play critical roles in the changes regulated by RR treatment.

In vivo antidiabetic evaluation of nanoparticles encompass dual bioflavonoid

Out of all the illness, Diabetes Mellitus (DM) is that the leading cause for morbidity and mortality worldwide. The overall international incidence of Diabetes mellitus is a rise from 171 million in 2000 to 366 million in 2030 as a result of various genetic level, fashionable life vogue factors like fatness, nutrition physical inactivity, ageing & stress. Hence hyperglycemic circumstance of diabetes patient is untreatable; however, the blood sugar level is controlled by daily administration of a dose of medicinal drug and medicine. At this juncture the isolates of the plant are used, within the gift study to use and make sure the possible medicinal drug and inhibitor activity mistreatment numerous in vivo models. Throughout this study, the associate initiative has been taken to check the activity of novelized preparation in addition to a pure drug to determine the efficiency of preparation. The work additionally designed to comprise a comparative illustration of activity of pure bioflavonoid, single loaded isolate nanoparticles and dual loaded nanoparticles. Therefore the primary aim of the analysis is to arrange Apigenin (Ap NP), Hesperidin (Hs NP) associated Apigenin -Hesperidin (Ap-Hs NP) twin loaded flavonol compound nanoparticles to beat the restrictions of Apigenin and Hesperidin synergistically augment of the therapeutic worth. Efficacy antidiabetic study was observed slightly decrease blood glucose level in diabetic rats treated with pure compound and with Ap and Hs loaded polymeric nanoparticles as compared to diabetic control rats.

Myricetin Possesses Anthelmintic Activity and Attenuates Hepatic Fibrosis via Modulating TGFβ1 and Akt Signaling and Shifting Th1/Th2 Balance in Schistosoma japonicum-Infected Mice.

Schistosomiasis is a zoonotic and debilitating parasitic disease caused by Schistosoma japonicum. Praziquantel remains the choice for treating schistosomiasis, but its efficacy could be hampered by emergence of resistance. In this study, using large-scale drug screening, we selected out myricetin, a natural flavonol compound, having a good anti-schistosome effect. We found that myricetin exhibited dose and time-dependent insecticidal effect on S. japonicum in vitro, with an LC50 of 600 μM for 24 h, and inhibited female spawning. The drug mainly destroyed the body structure of the worms and induced apoptosis of the worm cells, which in turn led to death. In addition, oral administration of myricetin in mice infected with S. japonicum showed a deworming effect in vivo, as evidenced by a significant reduction in the liver egg load. H&E staining, quantitative RT-PCR, and Western blotting assays showed that myricetin significantly alleviated liver fibrosis in mice infected with S. japonicum. Myricetin also effectively inhibited the expression of TGFβ1, Smad2, phospho-Smad2, Smad3, phospho-Smad3, ERK, phospho-ERK, Akt, and phospho-Akt in the liver of infected mice, suggesting that myricetin attenuated liver fibrosis in mice via modulating TGFβ1 and Akt signaling. Flow cytometric analysis of Th subtypes (Th1/Th2/Th17/Treg) in the mouse spleen further revealed that myricetin significantly increased the percentage Th1 cells in infected mice and reduced the proportion of Th2 cells and Th17 cells. Immunology multiplex assay further showed that myricetin attenuated S. japonicum-induced rise in the plasma levels of IL-4, IL-5, IL-10, IL-13, and IL-17A in infected mice while increasing the plasma contents of IFN-γ, IL-12, and IL-7. In conclusion, our study provides the first direct evidence that myricin possesses potent anti-schistosome activities in vitro and in vivo, and offers new insights into the mechanisms of action by myricetin. The present findings suggest that myricetin could be further explored as a therapeutic agent for S. japonicum.

Targeting staphylocoagulase with isoquercitrin protects mice from Staphylococcus aureus-induced pneumonia.

Staphylocoagulase (Coa) is a virulence factor of Staphylococcus aureus (S. aureus) that promotes blood coagulation by activating prothrombin to convert fibrinogen to fibrin. Coa plays a crucial role in disease pathogenesis and is a promising target for the treatment of S. aureus infections. Here, we identified that isoquercitrin, a natural flavonol compound, can markedly reduce the activity of Coa at concentrations that have no effect on bacterial growth. Mechanistic studies employing molecular dynamics simulation revealed that isoquercitrin binds to Coa by interacting with Asp-181 and Tyr-188, thereby affecting the binding of Coa to prothrombin. Importantly, in vivo studies showed that isoquercitrin treatment significantly reduced the bacterial burden, pathological damage, and inflammation of lung tissue and improved the percentage of survival of mice infected with S. aureus Newman strain. These data suggest that isoquercitrin is a promising inhibitor of Coa that can be used for the development of therapeutic drugs to combat S. aureus infections.Key Points• Staphylocoagulase plays a key role in the pathogenesis of S. aureus infection.• We identified that isoquercitrin is a direct inhibitor of staphylocoagulase.• Isoquercitrin treatment can significantly attenuate S. aureus virulence in vivo.

UHPLC-HR-MS/MS-Guided Recovery of Bioactive Flavonol Compounds from Greco di Tufo Vine Leaves.

Leaves of Vitis vinifera cv. Greco di Tufo, a precious waste made in the Campania Region (Italy), after vintage harvest, underwent reduction, lyophilization, and ultrasound-assisted maceration in ethanol. The alcoholic extract, as evidenced by a preliminary UHPLC-HR-MS analysis, showed a high metabolic complexity. Thus, the extract was fractionated, obtaining, among others, a fraction enriched in flavonol glycosides and glycuronides. Myricetin, quercetin, kaempferol, and isorhamnetin derivatives were tentatively identified based on their relative retention time and TOF-MS2 data. As the localization of saccharidic moiety in glycuronide compounds proved to be difficult due to the lack of well-established fragmentation pattern and/or the absence of characteristic key fragments, to obtain useful MS information and to eliminate matrix effect redundancies, the isolation of the most abundant extract’s compound was achieved. HR-MS/MS spectra of the compound, quercetin-3-O-glucuronide, allowed us to thoroughly rationalize its fragmentation pattern, and to unravel the main differences between MS/MS behavior of flavonol glycosides and glycuronides. Furthermore, cytotoxicity assessment on the (poly)phenol rich fraction and the pure isolated compound was carried out using central nervous system cell lines. The chemoprotective effect of both the (poly)phenol fraction and quercetin-3-O-glucuronide was evaluated.

Comparative metabolite fingerprinting of legumes using LC-MS-based untargeted metabolomics.

Legumes are a well-known source of phytochemicals and are commonly believed to have similar composition between different genera. To date, there are no studies evaluating changes in legumes to discover those compounds that help to discriminate for food quality and authenticity. The aim of this work was to characterize and make a comparative analysis of the composition of bioactive compounds between Cicer arietinum L. (chickpea), Lens culinaris L. (lentil) and Phaseolus vulgaris L. (white bean) through an LC-MS-Orbitrap metabolomic approach to establish which compounds discriminate between the three studied legumes. Untargeted metabolomic analysis was carried out by LC-MS-Orbitrap from extracts of freeze-dried legumes prepared from pre-cooked canned legumes. The metabolomic data treatment and statistical analysis were realized by using MAIT R's package, and final identification and characterization was done using MSn experiments. Fold-change evaluation was made through Metaboanalyst 4.0. Results showed 43 identified and characterized compounds displaying differences between the three legumes. Polyphenols, mainly flavonol and flavanol compounds, were the main group with 30 identified compounds, followed by α-galactosides (n = 5). Fatty acyls, prenol lipids, a nucleoside and organic compounds were also characterized. The fold-change analysis showed flavanols as the wider class of discriminative compounds of lentils compared to the other legumes; prenol lipids and eucomic acids were the most discriminative compounds of beans versus other legumes and several phenolic acids (such as primeveroside salycilic), kaempferol derivatives, coumesterol and α-galactosides were the most discriminative compounds of chickpeas. This study highlights the applicability of metabolomics for evaluating which are the characteristic compounds of the different legumes. In addition, it describes the future application of metabolomics as tool for the quality control of foods and authentication of different kinds of legumes.