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In genetically heterogeneous (UM-HET3) mice produced by the CByB6F1 × C3D2F1 cross, the Nrf2 activator astaxanthin (Asta) extended the median male lifespan by 12% (p = 0.003, log-rank test), while meclizine (Mec), an mTORC1 inhibitor, extended the male lifespan by 8% (p = 0.03). Asta was fed at 1840 ± 520 (9) ppm and Mec at 544 ± 48 (9) ppm, stated as mean ± SE (n) of independent diet preparations. Both were started at 12 months of age. The 90th percentile lifespan for both treatments was extended in absolute value by 6% in males, but neither was significant by the Wang-Allison test. Five other new agents were also tested as follows: fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate. None of these increased lifespan significantly at the dose and method of administration tested in either sex. Amounts of dimethyl fumarate in the diet averaged 35% of the target dose, which may explain the absence of lifespan effects. Body weight was not significantly affected in males by any of the test agents. Late life weights were lower in females fed Asta and Mec, but lifespan was not significantly affected in these females. The male-specific lifespan benefits from Asta and Mec may provide insights into sex-specific aspects of aging.

The influence of the composition of the functional used for density functional theory computations on one structural parameter (a dihedral angle) and a spectroscopic parameter (absorption wavelength) is assessed in this study on the basis of two molecules (flavonols). In this kind of molecules, these two parameters should be correlated according to the nature of the electronic transition involved. However, it is shown herein that by varying the proportion of true exchange and correlation while building a functional, it is possible to obtain independently a large range of values for these parameters without any relation with the underlying real values. Therefore, it is concluded that the choice of a functional after a benchmark, especially using user‐defined functionals, should be carried out with great care to avoid such effects. [ABSTRACT FROM AUTHOR]

Summary: Sea buckthorn (SB) is used in cuisines and herbal remedies due to its remarkable nutritional composition and health‐enhancing properties. The phenolic compounds present in SB plant include phenolic acids (gallic, p‐coumaric, protocatechuic and ferulic acids), flavonols (isorhamnetin, quercetin and kaempferol), flavan‐3‐ols and polymeric procyanidins. The highest content of these compounds was reported in branches and leaves than corresponding edible parts of the plant. The antioxidant properties of SB are related to content and composition of phenolic compounds in different plant parts. The studies reported SB flavonoids (isorhamnetin and quercetin) as main phenolic compounds with medicinal potential and health‐promoting effects. The present review summarises information available in recent studies on phenolic composition, phenolic content, flavonoid content, antioxidant activity and health‐promoting activities (anti‐oxidant, hepatoprotective, cardioprotective, anti‐inflammatory, anti‐diabetic and obesity management) of SB that can be used in curtailing various acute and chronic maladies. SB can be projected as a promising source of bioactive constituents with the potential to be used in healthy foods for beneficial effects on human health. [ABSTRACT FROM AUTHOR]

Wine pomace (WP) is a major byproduct generated during winemaking, and skin pomace (SKP) comprises one of the most valuable components of WP. Since SKP differs in composition and properties from seed pomace (SDP), precise knowledge of SKP will aid the wine industry in the development of novel, high-value products. The current review summarizes recent advances in research relating to SKP presents a comprehensive description of the generation, composition, and bioactive components, primarily focusing on the biological activities of SKP, including antioxidant, gastrointestinal health promotion, antibacterial, anti-inflammatory, anticancer, and metabolic disease alleviation properties. Currently, the separation and recovery of skins and seeds is an important trend in the wine industry for the disposal of winemaking byproducts. In comparison to SDP, SKP is rich in polyphenols including anthocyanins, flavonols, phenolic acids, stilbenes, and some proanthocyanidins, as well as dietary fiber (DF). These distinctive benefits afford SKP the opportunity for further development and application. Accordingly, the health-promoting mechanism and appropriate application of SKP will be further elucidated in terms of physiological activity, with the progress of biochemical technology and the deepening of related research. [ABSTRACT FROM AUTHOR]

To understand the effects and related potential mechanism of H2O2 on pigment metabolism in postharvest broccoli, an integrated analysis of transcriptome and metabolome was performed. Results suggested that 65 differentially expressed genes and 26 differentially accumulated metabolites involved in chlorophyll, carotenoid, and flavonoid metabolism were identified. H2O2 treatment delayed the decrease of chlorophyll content by upregulating the expressions of chlorophyll synthetic genes, thylakoid synthetic genes, and 15 light‐harvesting complex genes compared with the control and diphenylene iodonium treatments. H2O2 treatment decreased the accumulation of 11 flavonoids and 5 flavonols by downregulating the flavonoid synthetic genes. In addition, H2O2 treatment promoted carotenoid biosynthesis to eliminate reactive oxygen species in thylakoids, thereby protecting chlorophyll molecules from degradation. The inhibition of flavonoids and flavonols accumulation and chlorophyll decrease was the crucial reason for the delayed yellowing in H2O2 treatment. This study provides a new method and theoretical support for delaying the yellowing process in postharvest broccoli. [ABSTRACT FROM AUTHOR]

The present study assessed the impact of using irrigation water contaminated with Azithromycin (AZM) residues on the biomass and antioxidant compounds of purple corn; for this purpose, the plants were cultivated under ambient conditions, and the substrate used consisted of soil free from AZM residues, mixed with compost in a ratio of 1:1 (v/v). The experiment was completely randomized with four replications, with treatments of 0, 1, 10, and 100 μg/L of AZM. The results indicate that the presence of AZM in irrigation water at doses of 1 and 10 μg/L increases the weight of dry aboveground biomass, while at an amount of 100 μg/L, it decreases. Likewise, this study reveals that by increasing the concentration of AZM from 1 to 10 μg/L, total polyphenols and monomeric anthocyanins double, in contrast, with an increase to 100 μg/L, these decrease by 44 and 53%, respectively. It has been demonstrated that purple corn exposed to the antibiotic AZM at low doses has a notable antioxidant function in terms of DPPH and ORAC. The content of flavonols, phenolic acids, and flavanols increases by 57, 28, and 83%, respectively, when the AZM concentration is from 1 to 10 μg/L. However, with an increase to 100 μg/L, these compounds decrease by 17, 40, and 42%, respectively. On the other hand, stem length, root length, and dry weight of root biomass are not significantly affected by the presence of AZM in irrigation water. [ABSTRACT FROM AUTHOR]

Flavonoids play an important role in forming wine grapes and wine quality characteristics. The flavonoids of three winter red wine grapes, Yeniang No. 2 (YN2), Marselan (Mar), and Guipu No. 6 (GP6), were analyzed by ultra-high-performance liquid chromatography–triple quadrupole mass spectrometry (UPLC-QQQ-MS). Furthermore, the flavonoids in GP6 grapevines using two types of training systems, namely, trellis (T) and espaliers (E), were also compared in this study. Overall, 196 flavonoid metabolites, including 96 flavones, 38 flavonols, 19 flavanones, 18 polyphenols, 15 anthocyanins, 7 isoflavones, and 3 proanthocyanidins, were identified. The flavonoid profiles were remarkably different among these three grape varieties, while they did not change much in the GP6 managed on trellis and espaliers. Grape varieties with different genetic backgrounds have their own unique flavonoid profiles. Compared with Mar-T, isoflavones and flavonols presented higher contents in GP6-T and YN2-T, which mainly contain glycitein, genistin, calycosin, kaempferide, isotrifoliin, and ayanin. The anthocyanin content was significantly higher in YN2-T than in the other two varieties. YN2 and GP6-T present a more stable color, with significantly more acetylated diglucosides and methylated anthocyanins in YN2-T and GP6-T than in Mar-T. Notably, GP6 had more varied flavonoids and the better characteristics to its flavonoid profile out of these three varieties, due to it containing a higher number of anthocyanins, flavone, and flavonols and the greatest number of different flavonoid metabolites (DFMs), with higher contents than YN2 and Mar. Compared with the trellis training system, the espaliers training system increased the content of flavonoids detected in GP6 grape berries; however, the composition of flavonoids strictly depends on the grape variety. [ABSTRACT FROM AUTHOR]

Summary Reproduction in angiosperms relies on the precise growth of pollen tubes, facilitating the delivery of sperm cells to the ovule for double fertilization. LATERAL ORGAN BOUNDARIES DOMAIN10 (LBD10), a plant‐specific transcription factor, plays a pivotal role in Arabidopsis pollen development. Here, we uncovered LBD10's function in sustaining pollen tube growth and integrity. The lbd10 mutant exhibited elevated levels of reactive oxygen species (ROS) and hydrogen peroxide (H2O2) in both pollen grains and tubes, leading to compromised pollen tube growth. The inhibition of ROS synthesis and scavenging of excess ROS with an antioxidant treatment each alleviated these defects in lbd10. The lbd10 mutant displayed reduced flavonol accumulation in both pollen grains and tubes. All the altered phenotypes of lbd10 were complemented by expressing LBD10 under its native promoter. Exogenous application of flavonoids recused the defects in pollen tube growth and integrity in lbd10, along with reducing the excess levels of ROS and H2O2. LBD10 directly binds the promoters of key flavonol biosynthesis genes in chromatin and promotes reporter gene expression in Arabidopsis mesophyll protoplasts. Our findings indicate that LBD10 modulates ROS homeostasis by transcriptionally activating genes crucial for flavonol biosynthesis, thereby maintaining pollen tube growth and integrity. [ABSTRACT FROM AUTHOR]

In plants, salicylic acid (SA) hydroxylation regulates SA homoeostasis, playing an essential role during plant development and response to pathogens. This reaction is catalysed by SA hydroxylase enzymes, which hydroxylate SA producing 2,3‐dihydroxybenzoic acid (2,3‐DHBA) and/or 2,5‐dihydroxybenzoic acid (2,5‐DHBA). Several SA hydroxylases have recently been identified and characterised from different plant species, but no such activity has yet been reported in maize. In this work, we describe the identification and characterisation of a new SA hydroxylase in maize plants. This enzyme, with high sequence similarity to previously described SA hydroxylases from Arabidopsis and rice, converts SA into 2,5‐DHBA; however, it has different kinetic properties to those of previously characterised enzymes, and it also catalysers the conversion of the flavonoid dihydroquercetin into quercetin in in vitro activity assays, suggesting that the maize enzyme may have different roles in vivo to those previously reported from other species. Despite this, ZmS5H can complement the pathogen resistance and the early senescence phenotypes of Arabidopsis s3h mutant plants. Finally, we characterised a maize mutant in the S5H gene (s5hMu) that has altered growth, senescence and increased resistance against Colletotrichum graminicola infection, showing not only alterations in SA and 2,5‐DHBA but also in flavonol levels. Together, the results presented here provide evidence that SA hydroxylases in different plant species have evolved to show differences in catalytic properties that may be important to fine tune SA levels and other phenolic compounds such as flavonols, to regulate different aspects of plant development and pathogen defence. Summary statement: Maize plants express an enzyme of the 2‐oxoglutarate‐dependent oxygenase family with unique kinetic properties, having salicylic acid hydroxylase activity but it can also convert flavonols from dihydroflavonols. Zm2‐ODD7 confers increased resistance against pathogens and regulates senescence. [ABSTRACT FROM AUTHOR]

Flavonoids are usually present in forms of glucosides in plants, which could be catabolized by β‐glucosidase (BGLU) to form their corresponding flavonoid aglycones. In this study, we isolated three abiotic‐responsive BGLU genes (MtBGLU17, MtBGLU21 and MtBGLU22) from Medicago truncatula, and found only the recombinant MtBGLU17 protein could catalyse the hydrolysis of flavonoid glycosides. The recombinant MtBGLU17 protein is active towards a variety of flavonoid glucosides, including glucosides of flavones (apigenin and luteolin), flavonols (kaempferol and quercetin), isoflavones (genistein and daidzein) and flavanone (naringenin). In particular, the recombinant MtBGLU17 protein preferentially hydrolyses flavonoid‐7‐O‐glucosides over their corresponding 3‐O‐glucosides. The content of luteoin‐7‐O‐glucoside was reduced in the MtBGLU17 overexpression plants but increased in the Tnt‐1 insertional mutant lines, whereas luteoin content was increased in the MtBGLU17 overexpression plants but reduced in the Tnt‐1 insertional mutant lines. Under drought and salt (NaCl) treatment, the MtBGLU17 overexpression lines showed relatively higher DPPH content, and higher CAT and SOD activity than the wild type control. These results indicated that overexpression lines of MtBGLU17 possess higher antioxidant activity and thus confer drought and salt tolerance, implying MtBGLU17 could be potentially used as a candidate gene to improve plant abiotic stress tolerance. Summary statement: MtBGLU17 gene from Medicago truncatula encodes a β‐glucosidase that is able to hydrolyse a variety of flavonoid glucosides. Both gain‐of‐function and loss‐of‐function studies in M. truncatula demonstrated that MtBGLU17 is involved in drought and salt tolerance by balancing the accumulation of flavonoid aglycones with ROS scavenging activity. [ABSTRACT FROM AUTHOR]

Summary: In the present study, the effect of microwave roasting on the total phenolic quantities, antioxidant activities, phenolic constituents, fatty acids and tocopherol amounts of the pistachio kernel and oil was revealed. The moisture, oil, total phenolic amounts and antioxidant capacity value of raw and roasted pistachio nuts were assessed as 31.13%, 28.58%, 34.79 mgGAE/100 g and 0.75%–3.18%, 56.91%, 18.80 mgGAE/100 g and 2.26%, respectively. The raw pistachio nut contains 1.90 gallic acid, 0.22 3,4‐dihydroxybenzoic acid, 0.87 (+)‐catechin, 0.15 1,2‐dihydroxybenzene, 0.15 rutin trihydrate, 0.16 resveratrol, 0.1 quercetin, 0.19 kaempferol and 0.24 mg/100 g isorhamnetin. In addition, microwave‐roasted nuts contained 0.75 gallic acid, 0.62 3,4‐dihydroxybenzoic acid, 0.83 (+)‐catechin, 0.47 1,2‐dihydroxybenzene, 0.21 syringic acid, 0.17 caffeic acid and 0.17 mg/100 g quercetin. The raw and roasted pistachio nut oils contained 74.12% and 71.16% oleic, 13.76% and 15.23% linoleic, 8.16% and 8.92% palmitic and 2.09% and 2.10% stearic acids, respectively. The oil samples of the raw and roasted kernels contained 8.15 and 0.00 α‐tocopherol, 63.78 and 7.60 β‐tocopherol, 8.72 and 7.40 ɣ‐tocopherol and 5.61 and 6.77 mg g−1 δ‐tocopherols, respectively. The total phenolic quantity of the pistachio kernel roasted by microwave decreased significantly. Phenolic compounds of the pistachio kernel showed partial differences depending on microwave heating. Differences were monitored in the fatty acid profiles of Pistachio kernel oils. β‐tocopherol quantity of the oil of the pistachio kernel heated by microwave significantly decreased. [ABSTRACT FROM AUTHOR]

Background: Ziwan and Taoren (ZT) is a classic medicine pair in the formula of Mai Dong Di Shao Decoction, has been used to treat primary Sjogren's syndrome (pSS) for more than 20 years. But its action mechanism is still unknown. This study is aimed to reveal the potential mechanism of ZT treated pSS and discover its active compounds of ZT and therapeutic target for pSS. Methods: Firstly, the potential pathways of ZT for pSS treatment were predicted through network pharmacology and GO and KEGG enrichment analysis. Secondly, the inter-structural relationships between active compounds of ZT and target proteins were visualized using molecular docking techniques. Finally, efficacy and mechanism were conducted through in vivo experiments, such as water intake, spleen index, hematoxylin-eosin staining pathological changes, ELISA, Western Blot analysis, and immunofluorescence staining. Results: Nine active compounds were extracted from network pharmacology, including quercitrin, luteolin, kaempferol, β-sitosterol, isorhamnetin, galangin, hederagenin, diosmetin and gibberellin 7. Seven disease targets were identified: RELA, TP53, AKT1, interleukin (IL) 6, MAPK1, ESR1, IL10; with RELA being the most core target. KEGG and GO enrichment analysis indicated that ZT may act through the TLR/NF-κB/RELA inflammatory mechanism process. preliminary results of molecular docking showed that ZT's active compounds bind well to the RELA (p65) receptor. In vivo results demonstrated that a high dose of ZT significantly improved water intake and reduced lymphocytes infiltration in submandibular gland pathology in NOD mice. The expression content of AQP5 and vasoactive intestinal peptide in the submaxillary gland was significantly increased, while levels of inflammatory factors such as tumor necrosis factor-α, IL-6, and IL-1β along with protein expressions including toll-like receptor4, p-p65 and p-IKKα/β in NF-κB pathway were reduced. Conclusions: The ZT treatment exhibits a promising efficacy in mitigating dryness symptoms of pSS, potentially attributed to its capacity for suppressing the TLR/NF-κB inflammatory signaling pathway. [ABSTRACT FROM AUTHOR]

Pitaya flower, a medicinal and edible plant commonly used in tropical and subtropical regions, was the focus of this study, which compared the effects of hot-air drying (HAD) and vacuum drying (VD) on phytochemical profiles and biological activities of its four parts: calyx, petals, stamens, and pistils. Both drying methods significantly increased the total phenolic content (TPC) of pitaya flowers, with values ranging from 1.86 to 3.24 times higher than those of fresh samples. Twelve flavonoid compounds were identified in pitaya flowers, with the glycoside derivatives of three flavonols (kaempferol, isorhamnetin, and quercetin) being the most abundant. VD resulted in 1.15 times higher total flavonoid glycoside content than HAD, whereas in petals, HAD yielded a total flavonoid glycoside content 1.21 times higher than VD. Both HAD and VD effectively increased the antioxidant capacities of pitaya flowers, though the difference between the two methods was not significant. Additionally, both drying methods enhanced the antiproliferative activity of pitaya flowers, with HAD showing a more significant effect than VD. The present study emphasized the efficacy of drying methods for enhancing flavonoids in pitaya flowers and provided insights for functional products' innovation with different parts of pitaya flowers. [ABSTRACT FROM AUTHOR]

A number of studies have indicated the potential role of secondary metabolites, referred to as 'resistance factors', in plant defence against insect pests. Nevertheless, it remains unclear which metabolites serve as predictors of resistance in chrysanthemum cultivars against thrips. In the present study, the phenolic compounds of chrysanthemum leaves at different ontogenetic stages were analysed using high-performance liquid chromatography (HPLC). Furthermore, the relative epidermal flavonol contents in the leaves were quantified using the Dualex® Scientific 4 sensor, and the suitability of this non-destructive method for the rapid discrimination of resistance levels was evaluated. The results demonstrated that the most notable discrepancies in phenolic metabolite profiles were observed in the older leaves and the vegetative state of the chrysanthemum plants. Multiple discriminant analysis was conducted using HPLC-analysed metabolites to predict the importance of metabolites in resistant, susceptible, or highly susceptible plants in the vegetative stage. The results demonstrated that multiple metabolites, rather than a single metabolite, are responsible for thrips resistance in chrysanthemum. However, the relative flavonol content did not reflect the HPLC-analysed flavonoid glycosides or hydroxycinnamic acid derivatives, indicating that the Dualex® sensor is not a suitable device for determining resistance levels in chrysanthemums. Testing is required to extend and analyse the results in greater depth. [ABSTRACT FROM AUTHOR]

AbstractTraditional Chinese Medicine (TCM) formulations often contain a complex mixture of compounds, making it challenging to evaluate their quality. Buzhong Yiqi Oral Liquid (BYOL), a well-known TCM formulation, has been used to treat gastrointestinal diseases and fatigue for a long time. However, the effective substances for its therapeutic effects remain unclear. This study aimed to establish a novel quality control approach for BYOL using a multidimensional feature network to identify quality markers (Q-markers). The multidimensional characteristic network was constructed by a “Spider-Web” model, including the compatibility of ingredients, traceability of compounds from raw materials to the final product, effectiveness, measurability, and stability. Multivariate statistical analysis was applied to quantify the individual dimensions of the feature network, and candidate compounds were identified based on regression regions within the network. Using the multidimensional characteristic network, 12 components were identified as key Q-markers for BYOL, consisting of calycosin-7-O-β-D-glucoside, formononetin, astragaloside IV, liquiritin, quercetin, hesperidin, glycyrrhizic acid, isorhamnetin, liquiritin apioside, hesperidin, luteolin, and nobiletin. The identified Q-markers offered valuable insights for future research on medicinal substances and quality control of BYOL. [ABSTRACT FROM AUTHOR]

Chenopodium album L. (CAL) has many bioactive compounds and pharmacological activities. Fermentation is the preferred modification method of releasing target bioactive. We prepared two crude polysaccharides: SLC (the polysaccharide from the unfermented stem and leaves of CAL) and FSLC (the polysaccharide from the fermented stem and leaves of CAL). In vitro antioxidant and composition of SLC and FSLC were compared, and the effects of FSLC on antioxidant activity in the IPEC-J2 cells model and development-promoting activity in the zebrafish model were evaluated. The results revealed that FSLC possesses stronger DPPH, hydroxyl radical scavenging, and reducing power than SLC. The levels of total polysaccharide, polyphenol, and flavonoid, as well as the molar ratio of glucuronic acid increased in FSLC. Compared with SLC, the relative contents of protocatechuic acid, protocatechualdehyde, gentisic acid, vanillic acid, p-coumaric acid, quercetin, ferulic acid methyl ester, hispidulin, diosmetin, cinnamic acid, isorhamnetin, syringic acid and kaempferol in FSLC increased. In IPEC-J2 cells, antioxidant enzyme activities and GSH levels were significantly increased, while the MDA level was reduced by treatment with 0.25 mg/mL FSLC. In the zebrafish model, treatment with 25 ~ 300 μg/mL of FSLC had no harmful impact on the morphology and viability of embryos at 12 ~72 hpf. At 48 and 60 hpf, treatment with 100 ~ 300 μg/mL FSLC increased the hatching rate of embryos. At 72hpf, treatment with 100 ~ 300 μg/mL FSLC could relieve morphological abnormalities caused by LPS in zebrafish and improve the hatching rate of embryos. Together, these results provide useful information on the potential for applying polysaccharides from the stems and leaves of CAL as natural feed additives to exert its antioxidant and development-promoting functions. [ABSTRACT FROM AUTHOR]

Rhododendrons produce a variety of methoxyflavonoids, including rarely found 3-methoxyflavonoids and 5-methoxyflavonoids. It was thus suggested that they have a series of regiospecific flavonoid O-methyltransferases (FOMTs). The 18 Class II O-methyltransferase (OMT) genes were retrieved from the Rhododendron delavayi genome, designating them as RdOMTs. A comprehensive biochemical characterization of RdOMTs was performed to identify functional FOMTs. The FOMT activity of recombinant RdOMTs was assayed with flavonoid substrates of different subclasses. Among the examined RdOMTs, RdOMT3, RdOMT10, and RdOMT12 showed FOMT activity for diverse flavonoids. In particular, RdOMT3 consumed only flavonols as a substrate. Structural analyses of the methylated products demonstrated that RdOMT3, RdOMT10, and RdOMT12 catalyze regiospecific methylation of flavonoids at the 3'/5'-, 3-, and 4'-hydroxyl groups, respectively. Their broad substrate spectrum and different regiospecificity suggest that these RdOMTs contribute to the formation of complex methoxyflavonoids in R. delavayi. Bioconversion of flavonoids using E. coli harboring each RdOMT demonstrated that RdOMT3, RdOMT10, and RdOMT12 are useful tools for the biotechnological production of valuable methoxyflavonoids, including the rarely found 3-methoxyflavonoids. [ABSTRACT FROM AUTHOR]

SUMMARY: Skin color is an important trait that determines the cosmetic appearance and quality of fruits. In cucumber, the skin color ranges from white to brown in mature fruits. However, the genetic basis for this important trait remains unclear. We conducted a genome‐wide association study of natural cucumber populations, along with map‐based cloning techniques, on an F2 population resulting from a cross between Pepino (with yellow‐brown fruit skin) and Zaoer‐N (with creamy fruit skin). We identified CsMYB60 as a candidate gene responsible for skin coloration in mature cucumber fruits. In cucumber accessions with white to pale yellow skin color, a premature stop mutation (C to T) was found in the second exon region of CsMYB60, whereas light yellow cucumber accessions exhibited splicing premature termination caused by an intronic mutator‐like element insertion in CsMYB60. Transgenic CsMYB60c cucumber plants displayed a yellow‐brown skin color by promoting accumulation of flavonoids, especially hyperoside, a yellow‐colored flavonol. CsMYB60c encodes a nuclear protein that primarily acts as a transcriptional activator through its C‐terminal activation motif. RNA sequencing and DNA affinity purification sequencing assays revealed that CsMYB60c promotes skin coloration by directly binding to the YYTACCTAMYT motif in the promoter regions of flavonoid biosynthetic genes, including CsF3′H, which encodes flavonoid 3′‐hydroxylase. The findings of our study not only offer insight into the function of CsMYB60 as dominantly controlling fruit coloration, but also highlight that intronic DNA mutations can have a similar phenotypic impact as exonic mutations, which may be valuable in future cucumber breeding programs. Significance Statement: Genome‐wide association study and map‐based cloning revealed that CsMYB60 regulates mature cucumber fruit skin coloring, which is promising for cucumber breeding. Two loss‐of‐function mutations of CsMYB60 provided color variations in the natural cucumber population. [ABSTRACT FROM AUTHOR]

The medicinal plant Abrus precatorius L. was traditionally used in the Siddha and Ayurvedic systems of medicine in India. The Indian center of origin holds a vast variability in its seed color. The objective of this study was to assess the total monomeric anthocyanin, flavonol, as well as the antioxidative potential, protein content and ash content among the accessions. A total of 99 accessions conserved in the Indian National Genebank were used in this study. The methods used for the estimation of total monomeric anthocyanin, flavonol, as well as the antioxidative potential, protein content and ash content were the pH differential method, Oomah method, Ferric Reducing Antioxidant Potential, Dumas method and gravimetric method, respectively. The completely black colored accession was recorded with highest total monomeric anthocyanin (51.95 mg/100 g of cyanidin 3-glucoside equivalent) and flavonol content (66.41 mg/g of quercetin equivalent). Red + black colored accessions have recorded the maximum value with respect to antioxidants (14.18 mg/g of gallic acid equivalent). The highest amount of protein content was found in a completely white colored accession (20.67%) and the maximum ash content was recorded in red + black colored accession (4.01%). The promising accessions identified can be used by pharmaceutical companies in drug development and in curing degenerative diseases. [ABSTRACT FROM AUTHOR]

Background: The beneficial properties of wine by-products include actions that help prevent and treat cardiovascular conditions such as hypertension, primarily due to their antioxidant effects. Novel pharmacotherapies are being developed to treat arterial hypertension, including investigations into natural products exhibiting biological activity, necessitating rigorous evaluation of their efficacy and safety. This study aimed to identify and quantify phenolic compounds in Syrah (Vitis vinifera) grapes grown in the Brazilian Cerrado and their presence in winemaking by-products. It also examined the effects of grape pomace on blood pressure. Methods: Fresh grapes, pomace, and lees, were subjected to spectrophotometric determination of total phenolic compounds, followed by identification and quantification using HPLC-DAD-ESI-MSn. Normotensive male rats (Wistar) and spontaneously hypertensive rats (SHR) received grape pomace-enriched (150 or 300 mg/kg/day, 14 days) or standard chow. Indirect arterial pressure was assessed, while vascular reactivity was evaluated in mesenteric resistance arteries. Results: Pomace samples exhibited higher total phenolic compound concentrations than grapes or lees. Seven derivatives of hydroxycinnamic acids and twenty-one flavonols were identified. Quercetin-3-glucoside and ethyl caffeate were the most abundant phenolic compounds. Grape pomace-enriched chow demonstrated a dose-dependent hypotensive effect in rats. Conclusion: the abundance of flavonols and hydroxycinnamic acids, combined with their hypotensive effects, underscores the therapeutic potential of fine wine-making by-products produced in the Brazilian Cerrado. [ABSTRACT FROM AUTHOR]

The repurposing of therapeutic and preventive strategies against Alzheimer's disease (AD) is progressing rapidly. Pancratium aegyptiacum has been found to possess considerable anticholinesterase potential attributed to its alkaloid contents. In this study, the potential anti‐Alzheimer's activity of isolated flavonoids from P. aegyptiacum was investigated through computational analysis, focusing on the flavonoids rather than their well‐known alkaloids. Molecular docking was performed against three crucial targets involved in the development of AD, and the isolated phytoconstituents were analysed against these targets. Pathway enrichment analyses were also established, additionally, ADMETlab and PASS web servers predicted the pharmacological properties and potential biological functions of the isolated flavonoids. The phytochemical analysis of P. aegyptiacum aerial parts revealed the isolation and identification of eleven flavonoids. They were identified as derivatives of kaempferol (Km), quercetin (Qn) and isorhamnetin (Is). Our investigation revealed that these phytoconstituents potentially act against AD, with several phytochemicals showing superior binding affinity against essential AD targets. The Kyoto Encyclopaedia of Genes and Reactome pathway enrichment database revealed that isolated phytochemicals may have a role in regulating the immune pathway directly correlated to AD. Additionally, these phytochemicals exhibited lower toxicity with pleiotropic biological activities, including dementia treatment and neurotrophic factor enhancement. [ABSTRACT FROM AUTHOR]

Abiotic stress, especially drought stress, poses a significant threat to terrestrial plant growth, development, and productivity. Although mulberry has great genetic diversity and extensive stress-tolerant traits in agroforestry systems, only a few reports offer preliminary insight into the biochemical responses of mulberry leaves under drought conditions. In this study, we performed a comparative metabolomic and transcriptomic analysis on the "drooping mulberry" (Morus alba var. pendula Dippel) under PEG-6000-simulated drought stress. Our research revealed that drought stress significantly enhanced flavonoid accumulation and upregulated the expression of phenylpropanoid biosynthetic genes. Furthermore, the activities of superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) content were elevated. In vitro enzyme assays and fermentation tests indicated the involvement of flavonol synthase/flavanone 3-hydroxylase (XM_010098126.2) and anthocyanidin 3-O-glucosyltransferase 5 (XM_010101521.2) in the biosynthesis of flavonol aglycones and glycosides, respectively. The recombinant MaF3GT5 protein was found to recognize kaempferol, quercetin, and UDP-glucose as substrates but not 3-/7-O-glucosylated flavonols and UDP-rhamnose. MaF3GT5 is capable of forming 3-O- and 7-O-monoglucoside, but not di-O-glucosides, from kaempferol. This implies its role as a flavonol 3, 7-O-glucosyltransferase. The findings from this study provided insights into the biosynthesis of flavonoids and could have substantial implications for the future diversified utilization of mulberry. [ABSTRACT FROM AUTHOR]

Herein, a novel fluorescence probe Fla-DNP based on flavonol has been designed and synthesized for rapid, specific detection of H2S. With the addition of H2S, Fla-DNP triggered thiolysis and released Fla displaying the "turn-on" fluorescence response at 566 nm, which is consistent with the reaction site predicted by calculating Electrostatic potential and ADCH charges. As an easily available H2S probe, Fla-DNP has the advantages of high selectivity, anti-interference, low detection limit (0.834 μM), short response time (6 min), and large Stokes shift (124 nm). The sensing mechanism of H2S was determined by HRMS analysis and DFT calculation. Moreover, Fla-DNP processes a wide range of multiple applications, including the detection of H2S in environmental water samples with good recovery rates ranging from 89.6% to 102.0%, as well as tracking the production of H2S during food spoilage. Meanwhile, the probe exhibits superior biocompatibility and can not only be available used for H2S detection in living cells but be further designed as an H2S-activated CO photoreleaser, based on which it can be developed as a targeted anti-cancer drug. A novel fluorescence probe Fla-DNP was synthesized utilizing 4-dimethylaminobenzoxanthone fluorescent dye (Fla) as the fluorophore, 2, 4-dinitrobenzenether group (DNP) as the recognition group, which can rapidly respond to H2S with high selectivity, anti-interference, low detection limit (0.834 μM), short response time (6 min), and large Stokes shift (124 nm) characteristics. The practical applications of Fla-DNP were further explored in water, foodstuffs samples and living cells. It is reflected that Fla-DNP can not only track H2S in complex environment water, but also can detect H2S produced during foodstuffs spoilage to monitor food freshness. More importantly, Fla-DNP can be available used for H2S detection in living cells and utilize the properties of the photoinduced release of CO from flavonols to be designed as a bifunctional platform for H2S detection and CO release. It is demonstrated that H2S-activated CO photoreleaser Fla-DNP has promise for development as an anti-cancer drug. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether galangin (Gal) affects the proliferation, migration, invasion and apoptosis of osteosarcoma MG63 cells by regulating the cGAS/STING signaling pathway. Methods: Human osteosarcoma MG63 cells were cultured in vitro and treated with Gal at concentrations of 0, 5, 15, 25, 50, 100 and 200 μmol/L for 48 hours, and the effect of Gal on cell viability was detected by CCK-8 method. MG63 cells were divided into the control group (untreated cells), the Gal low concentration group (Gal-L group, treated with 50 μmol/L Gal), the Gal high concentration group (Gal-H group, treated with 100 μmol/L Gal), and the Gal-H+STING inhibitor group (Gal-H+H-151 group, treated with 100 μmol/L Gal+8 μmol/L H-151). EdU staining method, scratch healing test, Transwell chamber method and flow cytometry were used to detect cell proliferation, migration, invasion and apoptosis of cells in each group. Western blot was applied to detect the expression levels of cGAS and STING proteins in cells of each group. Results: Compared with the control group, the proliferation activity, migration, and invasion abilities of the cells in the Gal-L and Gal-H groups were significantly decreased (all P<0.05); the apoptosis rate and the expression levels of cGAS and STING proteins were significantly increased (all P<0.05). Compared with the Gal-H group, the proliferation activity, migration, and invasion abilities of the cells in the Gal-H+H-151 group were significantly increased (all P<0.05); the apoptosis rate and the expression levels of cGAS and STING proteins were significantly decreased (all P<0.05). Conclusion: Gal may inhibit the proliferation, migration and invasion and promote the apoptosis of osteosarcoma cells by activating the cGAS/STING signaling pathway. [ABSTRACT FROM AUTHOR]

The influence of the geographical location on the chemical composition of commercial Sauvignon Blanc wines was investigated. The assay was carried out on Sauvignon Blanc wines from three cold-climate valleys in Central Chile, Casablanca, Leyda, and San Antonio. The analyses revealed clear variations in some chemical parameters, especially in titratable acidity, which was higher in the geographical areas closest to the Pacific Ocean, such as the Leyda and San Antonio valleys. Regarding the composition of low-molecular-weight phenolic compounds, 17 compounds were found, and the results show that the Casablanca valley exhibits a greater abundance of monomeric flavanols, such as (+)-catechin, whereas the Leyda valley shows a higher abundance in flavonols and phenolic acids esterified with tartaric acid. Concerning the aromatic compound profile, the wines from the Casablanca valley showed a greater abundance of esters, C13 norisoprenoids, and some terpenes. The PLS-DA analysis revealed some differences, especially between wines from Casablanca and Leyda, demonstrating that the difference in the chemical composition of the wines was influenced by the geographical area. [ABSTRACT FROM AUTHOR]

The unique ecological environment of the Qinghai–Tibetan Plateau has endowed Chinese sea buckthorn leaves with rich bioactivities. In this study, we investigated the bioactivity and stress resistance mechanisms of flavonoids derived from Chinese sea buckthorn leaves (FCL) native to the Qinghai–Tibet Plateau. Our analysis identified a total of 57 flavonoids, mainly flavonol glycosides, from FCL, of which 6 were novel flavonoids. Isorhamnetin glycosides, quercetin glycosides and kaempferol glycosides were the three most dominant classes of compounds in FCL. In particular, isorhamnetin-3-O-glucoside-7-O-rhamnoside emerged as the most abundant compound. Our results showed that FCL possesses potent antioxidant properties, as evidenced by its ability to effectively scavenge DPPH free radicals and demonstrate ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) levels comparable to Trolox, a well-known antioxidant standard. Furthermore, FCL showed remarkable efficacy in reducing reactive oxygen species (ROS) levels and malondialdehyde (MDA) levels while enhancing the activities of key antioxidant enzymes, namely superoxide dismutase (SOD) and catalase (CAT), in Caenorhabditis elegans, a widely used model organism. Mechanistically, we elucidated that FCL exerts its stress resistance effects by modulating of transcription factors DAF-16 and HSF-1 within the insulin/insulin-like growth factor-1 signaling pathway (IIS). Activation of these transcription factors orchestrates the expression of downstream target genes including sod-3, ctl-1, hsp16.2, and hsp12.6, thus enhancing the organism's ability to cope with stressors. Overall, our study highlights the rich reservoir of flavonoids in Chinese sea buckthorn leaves as promising candidates for natural medicines, due to their robust antioxidant properties and ability to enhance stress resistance. [ABSTRACT FROM AUTHOR]

The incidence of neurological disorders, particularly age-related neurodegenerative pathologies, exhibits an alarming upward trend, while current pharmacological interventions seldom achieve curative outcomes. Despite their diverse clinical presentations, neurological diseases often share a common pathological thread: the aberrant accumulation of misfolded proteins within the endoplasmic reticulum (ER). This phenomenon, known as ER stress, arises when the cell's intrinsic quality control mechanisms fail to cope with the protein-folding burden. Consequently, misfolded proteins accumulate in the ER lumen, triggering a cascade of cellular stress responses. Recognizing this challenge, researchers have intensified their efforts over the past two decades to explore natural compounds that could potentially slow or even reverse these devastating pathologies. Flavonoids constitute a vast and heterogeneous class of plant polyphenols, with over 10,000 identified from diverse natural sources such as wines, vegetables, medicinal plants, and organic products. Flavonoids are generally divided into six different subclasses: anthocyanidins, flavanones, flavones, flavonols, isoflavones, and flavonols. The diverse family of flavonoids, featuring a common phenolic ring backbone adorned with varying hydroxyl groups and additional modifications, exerts its antioxidant activity by inhibiting the formation of ROS, as evidenced by research. Also, studies suggest that polyphenols such as flavonoids can regulate ER stress through apoptosis and autophagy. By understanding these mechanisms, we can unlock the potential of flavonoids as novel therapeutic agents for neurodegenerative disorders. Therefore, this review critically examines the literature exploring the modulatory effects of flavonoids on various steps of the ER stress in neurological disorders. [ABSTRACT FROM AUTHOR]

Main conclusions: The albino phenotype of Agave angustifolia Haw. accumulates higher levels of phenylalanine and phenylpropanoids, while the green phenotype has a greater concentration of phenolic compounds. The metabolic consequences of chlorophyll deficiency in plants continue to be a captivating field of research, especially in relation to production of metabolic compounds. This study conducts a thorough analysis of the metabolome in green (G), variegated (V), and albino (A) phenotypes of Agave angustifolia Haw. Specifically, it examines the differences in the accumulation of compounds related to the phenylpropanoid and flavonoid biosynthesis pathways. Methanol extracts of leaf and meristem tissues from the three phenotypes grown in vitro were analyzed using liquid chromatography coupled with quadrupole time-of-flight high-resolution mass spectrometry (UPLC-MS-QTOF) for untargeted metabolomics and triple quadrupole (QqQ) mass spectrometry for targeted metabolomic analyses. By employing these methods, we discovered notable differences in the levels of important metabolites such as L-phenylalanine, 4-hydroxyphenylpyruvic acid, and various flavonoids among the different phenotypes. The results of our study indicate that the A phenotype shows a significant increase in the levels of phenylalanine and phenylpropanoids in both leaf and meristem tissues. This is in contrast to a decrease in flavonoids, suggesting a metabolic reprogramming to compensate for the lack of chlorophyll. Significantly, compounds such as kaempferol-3-O-glucoside and rutin exhibited significant quantitative reduction in the A leaves, suggesting a subtle modification in the production of flavonols and potentially a changed mechanism for antioxidant protection. This study emphasizes the complex metabolic changes in A. angustifolia´s chlorophyll-deficient phenotypes, providing insight into the complex interplay between primary and secondary metabolism in response to chlorophyll deficiency. Our research not only enhances the comprehension of plant metabolism in albino phenotypes but also opens new avenues for exploring the biochemical and genetic basis of such adaptations, with potential biotechnological applications of these distinct plant variants. [ABSTRACT FROM AUTHOR]

SUMMARY Flavonols are widely synthesized throughout the plant kingdom, playing essential roles in plant physiology and providing unique health benefits for humans. Their glycosylation plays significant role in improving their stability and solubility, thus their accumulation and function. However, the genes encoding the enzymes catalyze this glycosylation remain largely unknown in apple. This study utilized a combination of methods to identify genes encoding such enzymes. Initially, candidate genes were selected based on their potential to encode UDP‐dependent glycosyltransferases (UGTs) and their expression patterns in response to light induction. Subsequently, through testing the in vitro enzyme activity of the proteins produced in Escherichia coli cells, four candidates were confirmed to encode a flavonol 3‐O‐galactosyltransferase (UGT78T6), flavonol 3‐O‐glucosyltransferase (UGT78S1), flavonol 3‐O‐xylosyltransferase/arabinosyltransferase (UGT78T5), and flavonol 3‐O‐rhamnosyltransferase (UGT76AE22), respectively. Further validation of these genes' functions was conducted by modulating their expression levels in stably transformed apple plants. As anticipated, a positive correlation was observed between the expression levels of these genes and the content of specific flavonol glycosides corresponding to each gene. Moreover, overexpression of a flavonol synthase gene, MdFLS, resulted in increased flavonol glycoside content in apple roots and leaves. These findings provide valuable insights for breeding programs aimed at enriching apple flesh with flavonols and for identifying flavonol 3‐O‐glycosyltransferases of other plant species. [ABSTRACT FROM AUTHOR]

Each year, agro-foods produce thousands of tonnes of by-products that contain high-value, unique nutrients. The application of plant by-products enables agro-food corporations to obtain value from them and avoid using natural resources. The idea of the bio economy protects against environmental pollution and leads to a cheap source of bioactive components, which can be transformed into value-added products for other industries. The numerous publications on the positive impact of sea buckthorn (SBT, Hippophae rhamnoides L., Elaeagnaceae family) and its products on human health mainly concern its fruits and seeds. However, there are few data relating to the properties of SBT leaves. The leaves of SBT can be a rich source of nutrients and biologically active substances. In this investigation, we report the study of the leaves of four SBT cultivars. We determined their antioxidant capacities, measured total polyphenols and total flavonoids, and quantified their major polyphenols and alkaloids. The results show that SBT leaves are a source of antioxidants and alkaloids. Additionally, in this raw material, we identified the presence of individual flavonols (rutoside and quercetin), individual anthocyanidins (cyaniding, delphinidin, and peonidin), and chelerythrine by high-performance thin-layer chromatography (HPTLC) for the first time. Through these types of studies, we aim to revalue this raw material, which is not well known in the world. Considering its nutritional properties, we seek to increase the use of its high-value, unique nutrients in food processing, medicine, and animal nutrition, in accordance with the goals of a closed-loop bioeconomy. [ABSTRACT FROM AUTHOR]

Background: Data from mechanistic studies suggest flavonoids may benefit glucose metabolism, but their associations with type 2 diabetes (T2D) remain unclear. This study examined the prospective associations of dietary intake of total, classes, and individual flavonoids, as well as their source foods, with T2D in the CArdioVascular disease Association Study (CAVAS). Methods: A total of 16,666 Korean men and women were enrolled at baseline, and 953 were newly diagnosed with T2D over a median follow-up of 5.96 years. Intake of flavonoids was cumulatively averaged using all food frequency questionnaires before the censoring events. A Poisson regression model was used to estimate incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Results: Women with higher total flavonoid, flavonol, isoflavone, and proanthocyanidin intake had a lower risk of T2D (fourth vs. first quartile, IRR 0.62; 95% CI 0.44–0.89; P for linearity and non-linearity < 0.05 for total flavonoids), while in men, flavanones, anthocyanins, and proanthocyanidins, but not total flavonoids, were inversely associated with T2D risk (all P interaction for sex > 0.05). The key source foods contributing to flavonoid intake were also different between men and women, except for apples: tangerines and strawberries in men and green leafy vegetables and soy products in women. Conclusions: A higher intake of total flavonoids, particularly from vegetables, soybeans, and apples, may be associated with lower risk of T2D in women. However, flavonoids from fruits, rather than total flavonoids, may be inversely associated in men. The association between flavonoid intake and the risk of T2D may be contingent upon the dietary sources of flavonoids consumed. [ABSTRACT FROM AUTHOR]

Flavonol and flavonoid compounds are important natural compounds with various biomedical activities. Therefore, it is of great significance to develop a strategy for the specific extraction of flavonol and flavonoid compounds. Quercetin is a well-studied flavonoid possessing many health benefits. This compound is a versatile antioxidant known to possess protective abilities against body tissue injury induced by pathological situations and various drug toxicities. Although quercetin is widely distributed in many plants, its content generally is not very high. Therefore, the specific extraction of quercetin as well as other flavonol and flavonoid compounds has profound significance. In this work, the quercetin molecularly imprinting polymer (QMIP) was successfully prepared, in which a typical flavonol quercetin was selected as the template molecule. QMIP was synthesized by performing the surface molecular imprinting technology on the surface of NH2-MIL-101(Fe). Our study results showed that QMIP exhibited quick binding kinetic behavior, a high adsorption capacity (57.04 mg/g), and the specific recognition ability toward quercetin compared with structurally distinct compounds (selective factor > 2). The specific adsorption ability of quercetin by QMIP was further explained using computation simulation that molecules with non-planar 3D conformations hardly entered the molecularly imprinted cavities on QMIP. Finally, QMIP was successfully used for the specific extraction of quercetin and five other flavonol and flavonoid compounds in the crude extracts from Sapium sebiferum. This study proposes a new strategy to synthesize the molecularly imprinted polymer based on a single template for enriching and loading a certain class of active ingredients with similar core structures from variable botanicals. [ABSTRACT FROM AUTHOR]

Research on bioactive compounds is essential to improve human health; promote adequate nutrition; drive innovation in the food, agricultural and biotechnology industries; and contribute to the preservation of the environment. The genus Diplotaxis (Brassicaceae) currently comprises around forty species, some of which are edible, particularly Diplotaxis tenuifolia (wild rocket), Diplotaxis erucoides (wall rocket), Diplotaxis muralis (annual wall rocket), Diplotaxis viminea (perennial wall rocket), and Diplotaxis simplex. The leaves of these species are rich in fiber and essential minerals, such as calcium, iron, potassium, and magnesium. Thirteen species have been characterized for their phenolic compounds, predominantly kaempferol, quercetin, and isorhamnetin glycosides. Furthermore, glucosinolate compounds were identified in nineteen species of the genus Diplotaxis. Many of the phytochemicals identified in Diplotaxis spp. demonstrated interesting biological activities, such as antioxidant, anti-inflammatory, antibacterial, hypoglycemic and hypolipidemic effects, as well as cytotoxicity and antiproliferative properties. This article provides a review of the phytochemistry of the Diplotaxis genus, highlighting its importance in food, its biological properties, potential pharmacological applications, and the dearth of research on many of these plants. [ABSTRACT FROM AUTHOR]

Rosehip fruits, characterized by their high concentrations of bioactive compounds and antioxidant activity (AA), have been traditionally used to make jams, infusions, and juices. Thus, the objective of this research was to evaluate the stability of rosehip juice by determining the concentrations of bioactive compounds and total phenols and the AA using chromatographic and spectroscopic methods. The stability of the juice was evaluated with three treatments and different storage conditions, namely, unpasteurized–refrigerated, pasteurized–room temperature, and pasteurized–refrigerated, and measurements were taken for eight months. Individual and total phenolic compounds, evaluated by chromatographic methods, reported differences until the end of this study. The total phenolic compounds by Folin–Ciocalteu method presented an average decrease of 57% in the three treatments in relation to the initial conditions. On the other hand, the ascorbic acid content decreased considerably, disappearing at week six. Furthermore, for the unpasteurized–refrigerated and pasteurized–refrigerated samples, a correlation was found between flavonols, total phenols, ascorbic acid, and antioxidant activity determined by the TEAC method. For the pasteurized–room temperature samples, correlations were found between the levels of several flavonols, hydroxycinnamic acid, total phenols, and ascorbic acid and the antioxidant activity determined by the CUPRAC method. The stability of the compounds was mainly correlated with the storage conditions of the juice and not with pasteurization. The highest stability was observed for the unpasteurized–refrigerated and pasteurized–refrigerated samples. Although the concentrations of the compounds evaluated decreased during this study, significant levels of AA persisted, providing beneficial characteristics for consumer health. [ABSTRACT FROM AUTHOR]

The flavone luteolin and the flavonol quercetin naturally occur in plants, providing some resistance against herbivores. However, despite suggesting the potential use of these compounds for plant protection, research on their relationship with aphids is limited. The aim of our study was to assess the effect of applying two flavonoids, quercetin and luteolin, at different concentrations, in vitro on the feeding behavior of the black bean aphid Aphis fabae Scopoli (Hemiptera: Aphididae). In most events associated with stylet activity, differences in probing behavior did not vary between the control gel and those with flavonoids. Higher concentrations of quercetin increased the number of penetrations, while lower concentrations of luteolin prolonged the first probing. The addition of flavonoids to the gels reduced passive ingestion. At a concentration of 0.1%, luteolin completely stopped salivation, and at 0.01%, it shortened the average duration of this activity. In events associated with active ingestion, differences in feeding behavior were observed between the control gel and those with quercetin at lower concentrations, affecting the time to the first stylet activity and the average time of active ingestion. Lower concentrations of luteolin prolonged the time to the first active ingestion, the duration of the first active ingestion, and the average time of this activity. Increased concentrations of quercetin and luteolin negatively affected aphid feeding behavior. Quercetin was better tolerated by A. fabae. A more noticeable effect was observed with an increase in luteolin concentration on the feeding behavior of A. fabae. These findings could be applied in biotechnological projects aiming to develop plants resistant to aphids and other herbivores. [ABSTRACT FROM AUTHOR]

Chalcone synthase (CHS) and chalcone isomerase (CHI) catalyze the first two committed steps of the flavonoid pathway that plays a pivotal role in the growth and reproduction of land plants, including UV protection, pigmentation, symbiotic nitrogen fixation, and pathogen resistance. Based on the obtained X-ray crystal structures of CHS, CHI, and chalcone isomerase-like protein (CHIL) from the same monocotyledon, Panicum virgatum, along with the results of the steady-state kinetics, spectroscopic/thermodynamic analyses, intermolecular interactions, and their effect on each catalytic step are proposed. In addition, PvCHI's unique activity for both naringenin chalcone and isoliquiritigenin was analyzed, and the observed hierarchical activity for those type-I and -II substrates was explained with the intrinsic characteristics of the enzyme and two substrates. The structure of PvCHS complexed with naringenin supports uncompetitive inhibition. PvCHS displays intrinsic catalytic promiscuity, evident from the formation of p-coumaroyltriacetic acid lactone (CTAL) in addition to naringenin chalcone. In the presence of PvCHIL, conversion of p-coumaroyl-CoA to naringenin through PvCHS and PvCHI displayed ~400-fold increased Vmax with reduced formation of CTAL by 70%. Supporting this model, molecular docking, ITC (Isothermal Titration Calorimetry), and FRET (Fluorescence Resonance Energy Transfer) indicated that both PvCHI and PvCHIL interact with PvCHS in a non-competitive manner, indicating the plausible allosteric effect of naringenin on CHS. Significantly, the presence of naringenin increased the affinity between PvCHS and PvCHIL, whereas naringenin chalcone decreased the affinity, indicating a plausible feedback mechanism to minimize spontaneous incorrect stereoisomers. These are the first findings from a three-body system from the same species, indicating the importance of the macromolecular assembly of CHS-CHI-CHIL in determining the amount and type of flavonoids produced in plant cells. [ABSTRACT FROM AUTHOR]

In recent years, the incidence of food-borne bacterial enteric diseases has increased worldwide causing significant health care and socioeconomic burdens. According to the World Health Organization, there are an estimated 600 million cases of foodborne illnesses worldwide each year, resulting in 420,000 deaths. Despite intensive efforts to tackle this problem, foodborne pathogenic microorganisms continue to be spread further. Therefore, there is an urgent need to find novel anti-microbial non-toxic compounds for food preservation. One way to tackle this issue may be the usage of polyphenols, which have received increasing attention in the recent years given their pleotropic health-promoting properties. This prompted us to perform a literature search summarizing studies from the past 10 years regarding the potential anti-microbial and disease-alleviating effects of plant-derived phenolic compounds against foodborne bacterial pathogens. The included 16 studies provide evidence that polyphenols show pronounced anti-bacterial and anti-oxidant effects against both Gram-positive and Gram-negative bacterial species. In addition, synergistic anti-microbial effects in combination with synthetic antibiotics were observed. In conclusion, phenolic compounds may be useful as natural anti-microbial agents in the food, agricultural, and pharmaceutical industries in the combat of foodborne infections. [ABSTRACT FROM AUTHOR]

Main conclusion: CsNAC086 was found to promote the expression of CsFLS, thus promoting the accumulation of flavonols in Camellia sinensis. Flavonols, the main flavonoids in tea plants, play an important role in the taste and quality of tea. In this study, a NAC TF gene CsNAC086 was isolated from tea plants and confirmed its regulatory role in the expression of flavonol synthase which is a key gene involved in the biosynthesis of flavonols in tea plant. Yeast transcription-activity assays showed that CsNAC086 has self-activation activity. The transcriptional activator domain of CsNAC086 is located in the non-conserved C-terminal region (positions 171–550), while the conserved NAC domain (positions 1–170) does not have self-activation activity. Silencing the CsNAC086 gene using antisense oligonucleotides significantly decreased the expression of CsFLS. As a result, the concentration of flavonols decreased significantly. In overexpressing CsNAC086 tobacco leaves, the expression of NtFLS was significantly increased. Compared with wild-type tobacco, the flavonols concentration increased. Yeast one-hybrid assays showed CsNAC086 did not directly regulate the gene expression of CsFLS. These findings indicate that CsNAC086 plays a role in regulating flavonols biosynthesis in tea plants, which has important implications for selecting and breeding of high-flavonols-concentration containing tea-plant cultivars. [ABSTRACT FROM AUTHOR]

Myricetin can be found in the traditional Chinese medicinal plant, Myrica rubra. Myricetin is a flavonoid that is present in many vegetables, fruits, and plants and is considered to have strong antioxidant properties as well as a wide range of therapeutic applications. Growing interest has been piqued by its classification as a polyphenolic molecule because of its potential therapeutic benefits in both the prevention and management of numerous medical conditions. To clarify myricetin's traditional medical uses, modern research has investigated various pharmacological effects such as antioxidant, anticancer, anti‐inflammation, antiviral, antidiabetic, immunomodulation, and antineurodegenerative effects. Myricetin shows promise as a nutritional flavonol that could be beneficial in the prevention and mitigation of prevalent health conditions like diabetes, cognitive decline, and various types of cancer in humans. The findings included in this study indicate that myricetin has a great deal of promise for application in the formulation of medicinal products and nutritional supplements since it affects several enzyme activities and alters inflammatory markers. However, comprehensive preclinical studies and research studies are necessary to lay the groundwork for assessing myricetin's possible effectiveness in treating these long‐term ailments. This review summarizes both in vivo and in vitro studies investigating myricetin's possible interactions through the nuclear factor‐E2‐related factor 2 (Nrf2) as well as PI3K (phosphatidylinositol 3‐kinase)/AKT (protein kinase B) signaling pathways in an attempt to clarify the compound's possible clinical applicability across a range of disorders. [ABSTRACT FROM AUTHOR]

Background: The flower colour of H. syriacus 'Qiansiban' transitions from fuchsia to pink–purple and finally to pale purple, thereby enhancing the ornamental value of the cultivars. However, the molecular mechanism underlying this change in flower colour in H. syriacus has not been elucidated. In this study, the transcriptomic data of H. syriacus 'Qiansiban' at five developmental stages were analysed to investigate the impact of flavonoid components on flower colour variation. Additionally, five cDNA libraries were constructed from H. syriacus 'Qiansiban' during critical blooming stages, and the transcriptomes were sequenced to investigate the molecular mechanisms underlying changes in flower colouration. Results: High-performance liquid chromatography‒mass spectrometry detected five anthocyanins in H. syriacus 'Qiansiban', with malvaccin-3-O-glucoside being the predominant compound in the flowers of H. syriacus at different stages, followed by petunigenin-3-O-glucoside. The levels of these five anthocyanins exhibited gradual declines throughout the flowering process. In terms of the composition and profile of flavonoids and flavonols, a total of seven flavonoids were identified: quercetin-3-glucoside, luteolin-7-O-glucoside, Santianol-7-O-glucoside, kaempferol-O-hexosyl-C-hexarbonoside, apigenin-C-diglucoside, luteolin-3,7-diglucoside, and apigenin-7-O-rutinoside. A total of 2,702 DEGs were identified based on the selected reference genome. Based on the enrichment analysis of differentially expressed genes, we identified 9 structural genes (PAL, CHS, FLS, DRF, ANS, CHI, F3H, F3'5'H, and UFGT) and 7 transcription factors (3 MYB, 4 bHLH) associated with flavonoid biosynthesis. The qRT‒PCR results were in good agreement with the high-throughput sequencing data. Conclusion: This study will establish a fundamental basis for elucidating the mechanisms underlying alterations in the flower pigmentation of H. syriacus. [ABSTRACT FROM AUTHOR]

Flavonoids, a class of phenolic compounds, are one of the main functional components and have a wide range of molecular structures and biological activities in Polygonatum. A few of them, including homoisoflavonoids, chalcones, isoflavones, and flavones, were identified in Polygonatum and displayed a wide range of powerful biological activities, such as anti-cancer, anti-viral, and blood sugar regulation. However, few studies have systematically been published on the flavonoid biosynthesis pathway in Polygonatum cyrtonema Hua. Therefore, in the present study, a combined transcriptome and metabolome analysis was performed on the leaf, stem, rhizome, and root tissues of P. cyrtonema to uncover the synthesis pathway of flavonoids and to identify key regulatory genes. Flavonoid-targeted metabolomics detected a total of 65 active substances from four different tissues, among which 49 substances were first study to identify in Polygonatum, and 38 substances were flavonoids. A total of 19 differentially accumulated metabolites (DAMs) (five flavonols, three flavones, two dihydrochalcones, two flavanones, one flavanol, five phenylpropanoids, and one coumarin) were finally screened by KEGG enrichment analysis. Transcriptome analysis indicated that a total of 222 unigenes encoding 28 enzymes were annotated into three flavonoid biosynthesis pathways, which were "phenylpropanoid biosynthesis", "flavonoid biosynthesis", and "flavone and flavonol biosynthesis". The combined analysis of the metabolome and transcriptome revealed that 37 differentially expressed genes (DEGs) encoding 11 enzymes (C4H, PAL, 4CL, CHS, CHI, F3H, DFR, LAR, ANR, FNS, FLS) and 19 DAMs were more likely to be regulated in the flavonoid biosynthesis pathway. The expression of 11 DEGs was validated by qRT-PCR, resulting in good agreement with the RNA-Seq. Our studies provide a theoretical basis for further elucidating the flavonoid biosynthesis pathway in Polygonatum. [ABSTRACT FROM AUTHOR]

Flavonol synthase gene (FLS) is a member of the 2-oxoglutarate-dependent dioxygenase (2-ODD) superfamily and plays an important role in plant flavonoids biosynthetic pathways. Safflower (Carthamus tinctorius L.), a key source of traditional Chinese medicine, is widely cultivated in China. Although the flavonoid biosynthetic pathway has been studied in several model species, it still remains to be explored in safflower. In this study, we aimed to elucidate the role of CtFLS1 gene in flavonoid biosynthesis and drought stress responses. The bioinformatics analysis on the CtFLS1 gene showed that it contains two FLS-specific motifs (PxxxIRxxxEQP and SxxTxLVP), suggesting its independent evolution. Further, the expression level of CtFLS1 in safflower showed a positive correlation with the accumulation level of total flavonoid content in four different flowering stages. In addition, CtFLS1-overexpression (OE) Arabidopsis plants significantly induced the expression levels of key genes involved in flavonol pathway. On the contrary, the expression of anthocyanin pathway-related genes and MYB transcription factors showed down-regulation. Furthermore, CtFLS1-OE plants promoted seed germination, as well as resistance to osmotic pressure and drought, and reduced sensitivity to ABA compared to mutant and wild-type plants. Moreover, CtFLS1 and CtANS1 were both subcellularly located at the cell membrane and nucleus; the yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assay showed that they interacted with each other at the cell membrane. Altogether, these findings suggest the positive role of CtFLS1 in alleviating drought stress by stimulating flavonols and anthocyanin accumulation in safflower. [ABSTRACT FROM AUTHOR]

With the depletion of the ozone layer, the intensity of ultraviolet B (UV-B) radiation reaching the Earth's surface increases, which in turn causes significant stress to plants and affects all aspects of plant growth and development. The aim of this study was to investigate the mechanism of response to UV-B radiation in the endemic species of Rhododendron chrysanthum Pall. (R. chrysanthum) in the Changbai Mountains and to study how exogenous ABA regulates the response of R. chrysanthum to UV-B stress. The results of chlorophyll fluorescence images and OJIP kinetic curves showed that UV-B radiation damaged the PSII photosystem of R. chrysanthum, and exogenous ABA could alleviate this damage to some extent. A total of 2148 metabolites were detected by metabolomics, of which flavonoids accounted for the highest number (487, or 22.67%). KEGG enrichment analysis of flavonoids that showed differential accumulation by UV-B radiation and exogenous ABA revealed that flavonoid biosynthesis and flavone and flavonol biosynthesis were significantly altered. GO analysis showed that most of the DEGs produced after UV-B radiation and exogenous ABA were distributed in the cellular process, cellular anatomical entity, and catalytic activity. Network analysis of key DFs and DEGs associated with flavonoid synthesis identified key flavonoids (isorhamnetin-3-O-gallate and dihydromyricetin) and genes (TRINITY_DN2213_c0_g1_i4-A1) that promote the resistance of R. chrysanthum to UV-B stress. In addition, multiple transcription factor families were found to be involved in the regulation of the flavonoid synthesis pathway under UV-B stress. Overall, R. chrysanthum actively responded to UV-B stress by regulating changes in flavonoids, especially flavones and flavonols, while exogenous ABA further enhanced its resistance to UV-B stress. The experimental results not only provide a new perspective for understanding the molecular mechanism of the response to UV-B stress in the R. chrysanthum, but also provide a valuable theoretical basis for future research and application in improving plant adversity tolerance. [ABSTRACT FROM AUTHOR]

Carrier‐free nanodrugs that integrate chemodrugs and other therapeutic agents demonstrate good efficacy and minimized side effects, showing promise for combined therapy. However, a key challenge lies in enhancing the bioavailability and therapeutic potential of the nanodrugs through a controllable assembly process. Herein, a carrier‐free photothermal nanodrug (ZPQ NPs) is constructed through flavonol‐driven assembly with amine‐substituted perylene diimide for enhanced chemo‐photothermal combined cancer therapy. The flavonol, particularly quercetin, facilitates J‐aggregation of perylene diimide derivatives within the nanodrug and contributes to multiple improvements, including red‐shifted absorption, enhanced fluorescence intensity, improved photothermal conversion efficiency as well as excellent photostability. Moreover, the nanodrug also demonstrates enhanced cellular uptake and intracellular reactive oxygen species scavenging capability. The combination of quercetin and photothermal effect effectively kills cancer cells, as well as alleviates inflammation following photothermal therapy. Guided by in vivo fluorescence imaging, the application of ZPQ NPs results in complete tumor elimination and effectively inhibits tumor recurrence through chemo‐photothermal combined therapy. This work presents a straightforward strategy for constructing carrier‐free nanodrugs that exhibit simultaneous enhancements in both photophysical properties and biological activity. [ABSTRACT FROM AUTHOR]

Despite the rapid and dynamic evolution of research into dietary polyphenols, there is still a knowledge gap regarding their bioaccessibility since it could be influenced by the chemical and nutritional compositions of the food matrix. This study aimed to describe the impact of food thickeners (xanthan gum, guar gum, β-glucan, pectin) on the bioactivity of flavonoids from saffron floral by-products in model beverages before and after thermal processing. The different beverage formulas were characterized in terms of polyphenolic composition using HPLC-DAD-ESI-MSn and rheological properties. The impact of food thickeners and thermal processing on the inhibition of digestive enzymes was also determined. The model beverages mainly presented glycosylated flavonols (of kaempferol, quercetin, and isorhamnetin), with a reduced content in some heat-treated samples. The inhibitory effect on α-amylase was only detected in heat-treated beverages, showing the formulation without any thickener to have the greatest inhibitory effect. Finally, the presence of saffron floral by-products in the beverages showed a tendency to decrease the flow consistency index (K) and an increase in the flow behavior index (n), most probably driven by the aggregation of phenolics with thickeners. Therefore, this research provides new insights into the development of flavonoid-rich beverages in order to ensure that they exert the expected beneficial effects after their ingestion. [ABSTRACT FROM AUTHOR]

Aronia melanocarpa berries contain many compounds with potential benefits for human health. The food flavonoids quercetin and rutin, found in significant amounts in the fruits of A. melanocarpa, are known to have favourable effects on animal and human organisms. However, data on the effect of flavonols isolated from black chokeberry on immune functions during immunosuppression are not available in the literature. Thus, the aim of this study was to evaluate the effect of flavonol fraction isolated from A. melanocarpa fruits, in comparison with pure quercetin and rutin substances, on the dysfunctional state of rat thymus and spleen in immunodeficiency. The study was performed on Wistar rats. The animals were orally administered solutions of the investigated substances for 7 days: water, a mixture of quercetin and rutin and flavonol fraction of A. melanocarpa. For induction of immunosuppression, the animals were injected once intraperitoneally with cyclophosphamide. Substance administration was then continued for another 7 days. The results showed that under the influence of flavonols, there was a decrease in cyclophosphamide-mediated reaction of lipid peroxidation enhancement and stimulation of proliferation of lymphocytes of thymus and spleen in rats. At that, the effect of the flavonol fraction of aronia was more pronounced. [ABSTRACT FROM AUTHOR]

A series of flavanols were synthesized to assess their biological activity against human non-small cell lung cancer cells (A549). Among the sixteen synthesized compounds, it was observed that compounds 6k (3.14 ± 0.29 µM) and 6l (0.46 ± 0.02 µM) exhibited higher potency compared to 5-fluorouracil (5-Fu, 4.98 ± 0.41 µM), a clinical anticancer drug which was used as a positive control. Moreover, compound 6l (4'-bromoflavonol) markedly induced apoptosis of A549 cells through the mitochondrial- and caspase-3-dependent pathways. Consequently, compound 6l might be developed as a candidate for treating or preventing lung cancer. [ABSTRACT FROM AUTHOR]

The Chilean Puya species, Puya coerulea var. violacea and P. chilensis bear blue and pale-yellow flowers, respectively, while P. alpestris considered to be their hybrid-derived species has unique turquoise flowers. In this study, the chemical basis underlying the different coloration of the three Puya species was explored. We first isolated and identified three anthocyanins: delphinidin 3,3ʹ,5ʹ-tri-O-glucoside, delphinidin 3,3′-di-O-glucoside and delphinidin 3-O-glucoside; seven flavonols: quercetin 3-O-rutinoside-3′-O-glucoside, quercetin 3,3ʹ-di-O-glucoside, quercetin 3-O-rutinoside, isorhamnetin 3-O-rutinoside, myricetin 3,3ʹ,5ʹ-tri-O-glucoside, myricetin 3,3ʹ-di-O-glucoside and laricitrin 3,5ʹ-di-O-glucoside; and six flavones: luteolin 4ʹ-O-glucoside, apigenin 4′-O-glucoside, tricetin 4ʹ-O-glucoside, tricetin 3ʹ,5ʹ-di-O-glucoside, tricetin 3ʹ-O-glucoside and selagin 5ʹ-O-glucoside, which is a previously undescribed flavone, from their petals. We also compared compositions of floral flavonoid and their aglycone among these species, which suggested that the turquoise species P. alpestris has an essentially intermediate composition between the blue and pale-yellow species. The vacuolar pH was relatively higher in the turquoise (pH 6.2) and pale-yellow (pH 6.2) flower species, while that of blue flower species was usual (pH 5.2). The flower color was reconstructed in vitro using isolated anthocyanin, flavonol and flavone at neutral and acidic pH, and its color was analyzed by reflectance spectra and the visual modeling of their avian pollinators. The modeling demonstrated that the higher pH of the turquoise and pale-yellow species enhances the chromatic contrast and spectral purity. The precise regulation of flower color by flavonoid composition and vacuolar pH may be adapted to the visual perception of their avian pollinator vision. [ABSTRACT FROM AUTHOR]

Acne vulgaris is a prevalent skin disorder affecting many young individuals, marked by keratinization, inflammation, seborrhea, and colonization by Cutibacterium acnes (C. acnes). Ellagitannins, known for their antibacterial and anti-inflammatory properties, have not been widely studied for their anti-acne effects. Chestnut (Castanea sativa Mill., C. sativa), a rich ellagitannin source, including castalagin whose acne-related bioactivity was previously unexplored, was investigated in this study. The research assessed the effect of C. sativa leaf extract and castalagin on human keratinocytes (HaCaT) infected with C. acnes, finding that both inhibited IL-8 and IL-6 release at concentrations below 25 μg/mL. The action mechanism was linked to NF-κB inhibition, without AP-1 involvement. Furthermore, the extract displayed anti-biofilm properties and reduced CK-10 expression, indicating a potential role in mitigating inflammation, bacterial colonization, and keratosis. Castalagin's bioactivity mirrored the extract's effects, notably in IL-8 inhibition, NF-κB inhibition, and biofilm formation at low μM levels. Other polyphenols, such as flavonol glycosides identified via LC-MS, might also contribute to the extract's biological activities. This study is the first to explore ellagitannins' potential in treating acne, offering insights for developing chestnut-based anti-acne treatments pending future in vivo studies. [ABSTRACT FROM AUTHOR]

The azalea (Rhododendron simsii Planch.) is an important ornamental woody plant with various medicinal properties due to its phytochemical compositions and components. However little information on the metabolite variation during flower development in Rhododendron has been provided. In our study, a comparative analysis of the flavonoid profile was performed in Rhododendron pulchrum sweet at three stages of flower development, bud (stage 1), partially open flower (stage 2), and full bloom (stage 3). A total of 199 flavonoids, including flavone, flavonol, flavone C-glycosides, flavanone, anthocyanin, and isoflavone were identified. In hierarchical clustering analysis (HCA) and principal component analysis (PCA), the accumulation of flavonoids displayed a clear development stage variation. During flower development, 78 differential accumulated metabolites (DAMs) were identified, and most were enriched to higher levels at the full bloom stage. A total of 11 DAMs including flavone (chrysin, chrysoeriol O-glucuronic acid, and chrysoeriol O-hexosyl-O-pentoside), isoflavone (biochanin A), and flavonol (3,7-di-O-methyl quercetin and isorhamnetin) were significantly altered at three stages. In particular, 3,7-di-O-methyl quercetin was the top increased metabolite during flower development. Furthermore, integrative analyses of metabolomic and transcriptomic were conducted, revealing that the contents of isoflavone, biochanin A, glycitin, and prunetin were correlated with the expression of 2-hydroxyisoflavanone dehydratase (HIDH), which provide insight into the regulatory mechanism that controls isoflavone biosynthesis in R. pulchrum. This study will provide a new reference for increasing desired metabolites effectively by more accurate or appropriate genetic engineering strategies. [ABSTRACT FROM AUTHOR]