Simultaneous quantitation of 15 bioactive components in Yupingfeng granules by LC-MS/MS

Yupingfeng granules (YPFG) is commonly used in the treatment of immunological diseases, inflammations, and pulmonary diseases. Several studies have found that chromones, flavones, and saponins were the major bioactive compounds of YPFG. However, few studies have reported accurate quantification methods of these compounds. This study aimed to establish a simple and rapid method by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine 15 bioactive compounds in YPFG. The experimental parameters including extraction methods, extraction solvents, extraction time, solid-liquid ratio, and LC-MS/MS condition were optimized. The linearity, precision, repeatability, stability, and recovery of the established method were evaluated. The contents of 15 bioactive compounds in seven batches of YPFG samples were analyzed by the established method and the results were compared with the values determined by HPLC. The optimal extraction condition was to extract 0.1 g of YPFG by ultrasound with 50 mL 50% ethanol for 30 min. A Waters ACQUITY UPLCBEH C18 column using the 0.1% formic acid water solution and acetonitrile as mobile phase with a gradient elution was applied to the chromatographic separation. The linearity, precision, repeatability, stability, and recovery of the method were within acceptable ranges. Compared with HPLC analysis methods in Chinese Pharmacopoeia and literature, the established method was faster, simpler, more accurate, and more reliable. The method of simultaneous determination of 15 components in YPFG by LC-MS might provide a basis for the study of the bioactive compounds and the improvement of the quality standard of YPFG.

Characterization of Neuropeptides from Spodoptera litura and Functional Analysis of NPF in Diet Intake

Neuropeptides are involved in many biological processes in insects. However, it is unclear what role neuropeptides play in Spodoptera litura adaptation to phytochemical flavone. In this study, 63 neuropeptide precursors from 48 gene families were identified in S. litura, including two neuropeptide F genes (NPFs). NPFs played a positive role in feeding regulation in S. litura because knockdown of NPFs decreased larval diet intake. S. litura larvae reduced flavone intake by downregulating NPFs. Conversely, the flavone intake was increased if the larvae were treated with NPF mature peptides. The NPF receptor (NPFR) was susceptible to the fluctuation of NPFs. NPFR mediated NPF signaling by interacting with NPFs to regulate the larval diet intake. In conclusion, this study suggested that NPF signaling regulated diet intake to promote S. litura adaptation to flavone, which contributed to understanding insect adaptation mechanisms to host plants and provide more potential pesticidal targets for pest control.

[Study on chemical components of Hypericum himalaicum and mechanism of anti-inflammatory based on network pharmacology and molecular docking technology]

The chemical constituents of ethyl acetate from Hypericum himalaicum were isolated by silica gel column chromatography, gel column chromatography, and high-performance liquid chromatography. The structure of the isolated compounds was identified by modern spectral techniques(NMR, MS, IR, and UV), and the potential anti-inflammatory targets and action pathways were analyzed and predicted by network pharmacology and molecular docking methods.Ten compounds were isolated from H. himalaicum and identified as 5,9,11-trihydroxy-3,3-dimethyl-3H,8H-benzo[6,7][1,4]dioxepino[2,3-f]chromen-8-one(1), betulinic acid(2), demethyltorosaflavone C(3), kaempferol(4), quercetin(5), hyperwightin B(6), toxyloxanthone B(7), 1,7-dihydroxy-xanthone(8), emodin(9), and 1,7-dihydroxy-4-methoxy-xanthone(10). Among them, compound 1 was a new compound, and compounds 2-10 were isolated from H. himalaicum for the first time. Network pharmacology screened 60 key anti-inflammatory targets. By acting on TNF, AKT1, CASP3, and other key targets, involving PI3K-AKT signaling pathway, IL-17 signaling pathway, VEGF signaling pathway, MAPK signaling pathway, and other signaling pathways, and phosphorylation, cell migration and movement, protein tyrosine kinase, and other biological processes were regulated to achieve anti-inflammatory effects. The results of molecular docking show that the above components have good binding properties with the core targets.

Correlation between Colour Traits and Intrinsic Quality of Dalbergiae Odoriferae Lignum

Dalbergia odorifera T. Chen is traditionally referred to as "Dalbergiae Odoriferae Lignum" in traditional Chinese medicine. Its quality is typically assessed subjectively based on colour and texture observations and lacks a universal grading system. Our objective was to establish a relationship between heartwood colour and the content of key constituents, including total flavonoids, six specific flavonoids, alcohol-soluble extracts, and volatile oils, to assess their impact on heartwood quality. Substantial correlations were observed between the colour depth (L*), red-green direction (a*), and yellow-blue direction (b*), as well as the content of the extract, volatile oil, total flavonoids, naringenin, formononetin, pinocembrin, and isoliquiritigenin. Specifically, a* was correlated with the extract, total flavonoids, and isoliquiritigenin, whereas b* was correlated with the extract, volatile oil, total flavonoids, naringenin, formononetin, pinocembrin, and isoliquiritigenin. The results suggested that L*, b*, and chemical composition indices, such as extract, volatile oil, total flavonoids, and naringenin, could serve as primary criteria for classifying the quality of medicinal materials. This is consistent with market classification based on colour and texture, which facilitates material identification and guides the cultivation, harvesting, and processing of D. odorifera. This study provides a scientific foundation for its future development and use.

The Antioxidative Effects of Flavones in Hypertensive Disease

Hypertension is the leading remediable risk factor for cardiovascular morbidity and mortality in the United States. Excess dietary salt consumption, which is a catalyst of hypertension, initiates an inflammatory cascade via activation of antigen-presenting cells (APCs). This pro-inflammatory response is driven primarily by sodium ions (Na+) transporting into APCs by the epithelial sodium channel (ENaC) and subsequent NADPH oxidase activation, leading to high levels of oxidative stress. Oxidative stress, a well-known catalyst for hypertension-related illness development, disturbs redox homeostasis, which ultimately promotes lipid peroxidation, isolevuglandin production and an inflammatory response. Natural medicinal compounds derived from organic materials that are characterized by their anti-inflammatory, anti-oxidative, and anti-mutagenic properties have recently gained traction amongst the pharmacology community due to their therapeutic effects. Flavonoids, a natural phenolic compound, have these therapeutic benefits and can potentially serve as anti-hypertensives. Flavones are a type of flavonoid that have increased anti-inflammatory effects that may allow them to act as therapeutic agents for hypertension, including diosmetin, which is able to induce significant arterial vasodilation in several different animal models. This review will focus on the activity of flavones to illuminate potential preventative and potential therapeutic mechanisms against hypertension.

Puncturing lipid membranes: onset of pore formation and the role of hydrogen bonding in the presence of flavonoids

Products of lipid peroxidation induce detrimental structural changes in cell membranes, such as the formation of water pores, which occur in the presence of lipids with partially oxidized chains. However, the influence of another class of products, dicarboxylic acids, is still unclear. These products have greater mobility in the lipid bilayer, which enables their aggregation and the formation of favorable sites for the appearance of pores. Therefore, dodecanedioic acid (DDA) was selected as a model product. Additionally, the influence of several structurally different flavonoids on DDA aggregation via formation of hydrogen bonds with carboxyl groups was investigated. The molecular dynamics of DDA in DOPC lipid bilayer revealed the formation of aggregates extending over the hydrophobic region of the bilayer and increasing its polarity. Consequently, water penetration and the appearance of water wires was observed, representing a new step in the mechanism of pore formation. Furthermore, DDA molecules were found to interact with lipid polar groups, causing them to be buried in the bilayer. The addition of flavonoids to the system disrupted aggregate formation, resulting in the displacement of DDA molecules from the center of the bilayer. The placement of DDA and flavonoids in the lipid bilayer was confirmed by small-angle X-ray scattering. Atomic force microscopy and electron paramagnetic resonance were used to characterize the structural properties. The presence of DDA increased bilayer roughness and decreased the ordering of lipid chains, confirming its detrimental effects on the membrane surface, while flavonoids were found to reduce or reverse these changes.

Determination of Phytochemical Contents in Extracts from Different Growth Stages of Oroxylum indicum Fruits Using HPLC-DAD and QAMS Methods

Flavones are major compounds found in several parts of Oroxylum indicum (O. indicum). The quantification of multiple components by one marker (QAMS) method and the high-performance liquid chromatography (HPLC) method were developed for the quantitative analysis of extracts from the young fruits, green mature fruits, dry pod coats and seeds of O. indicum. Oroxin A, oroxin B and chrysin-7-O-glucuronide were identified in the O. indicum extracts. Oroxylin A and 5-hydroxymethylfurfural were isolated and structurally identified from the pod coat and young fruit extracts, respectively. From the HPLC analysis of the seven major flavones in the extracts, baicalin was the major compound in all extracts investigated (0.4-11% w/w of the extract). All flavone contents were low in the young fruit extract (<1% w/w of the extract). The green mature fruit and dry pod coat extracts showed similar constituent compositions. They contained small amounts of baicalin and oroxylin A, which were found only in these two extracts. Oroxylin A could be used as a marker to indicate the maturity of O. indicum fruits, while 5-hydroxymethylfurfural could be used as a marker for the young fruits. Baicalin was found to be a suitable single marker to calculate the contents of all flavones in the O. indicum extracts.

A pair of diastereoisomeric C-glucofuranosyl flavones from the flowers of Gypsophila oldhamiana

Two new C-glucofuranosyl flavones apigenin 6-C-β-glucofuranoside (1) and apigenin 6-C-α-glucofuranoside (2) together with four known compounds (3-6) were isolated from the flowers of Gypsophila oldhamiana. Their structures were elucidated on the basis of extensive spectroscopic analyses. These compounds were evaluated for the cytotoxic activities against four human cancer cell lines and did not exhibit any significant bioactivities (IC50 values > 10 μM).

Design, Synthesis, and Pharmacological Evaluation of Novel Tacrine Derivatives as Multi-target ANTI-Alzheimer's Agents In Rat Models

BACKGROUND

Alzheimer's disease is a progressive neurodegenerative disorder for which no curative drugs are available and treatment available is just palliative.

OBJECTIVES

Current research focused on design of Tacrine-Flavone hybrids as multitargeted cholinesterase and monoamine oxidase B inhibitors.

METHODS

A total of 10 Tacrine- Flavone hybrids were designed, synthesized and characterized. The in vitro neurotoxicity and hepatotoxicity of the synthesized compounds determined using SHSY5Y cell line and HEPG2 cell line. One most active compound (AF1) with least toxicity in in vitro studies was chosen for in vivo studies. Acute and subacute toxicity of the novel compound AF1 conducted on Wistar rats according to OECD guideline 423 and 407. The LD50 value of the novel compound calculated according to Finney's method using Probit analysis. Anti-Alzheimer's activity studies conducted on male Wistar rats. Behavioral studies conducted and AChE and MAO-B activity determined in rat brain.

RESULTS AND DISCUSSION

All the compounds exhibited good inhibitory effect on MAO B and AChE. The neurotoxicity studies of the active compound AF1 did not show toxicity up to 100μg. The hepatotoxicity study of the most active compound AF1, showed the compound to be safe up to 200μg. The LD 50 value of the novel compound after a single oral administration was found to be 64 mg/kg bodyweight in rats. Subacute toxicity studies did not show any remarkable toxicity in the vital organs up to 40 mg/kg. Activity studies showed comparable results with standard at 20 mg/kg.

CONCLUSION

The results showed that the novel Tacrine-Flavone hybrids are multitarget-directed ligands, which are safe and active compared to tacrine and can be a promising lead molecule for further study.

Development and Optimization of Culture Medium for the Production of Glabridin by Aspergillus eucalypticola: An Endophytic Fungus Isolated from Glycyrrhiza glabra L. (Fabaceae)

Glabridin is a well-known active isoflavone found in the root of licorice (Glycyrrhiza glabra L.) that possess a wide range of biological activity. Plant cells, hairy roots, and fungal endophytes cultures are the most important alternative methods for plant resources conservation and sustainable production of natural compounds, which has received much attention in recent decades. In the present study, an efficient culture condition was optimized for the biomass accumulation and glabridin production from fungal endophyte Aspergillus eucalypticola SBU-11AE isolated from licorice root. Type of culture medium, range of pH, and licorice root extract (as an elicitor) were tested. The results showed that the highest and lowest biomass production was observed on PCB medium (6.43 ± 0.32 g/l) and peptone malt (5.85 + 0.11 g/l), respectively. The medium culture PCB was produced the highest level of glabridin (7.26 ± 0.44 mg/l), while the lowest level (4.47 ± 0.02 mg/l) was obtained from the medium peptone malt. The highest biomass (8.51 ± 0.43 g/l) and glabridin (8.30 ± 0.51 mg/l) production were observed from the PCB medium adjusted with pH = 6, while the lowest value of both traits was obtained from the same medium with pH = 7. The highest production of total glabridin (10.85 ± 0.84 mg/l) was also obtained from the culture medium treated with 100 mg/l of the plant root extract. This information can be interestingly used for the commercialization of glabridin production for further industrial applications.

Hetero-grafting affects flavonoid biosynthesis in sweet orange 'Newhall' (Citrus sinensis) peels: a metabolomics and transcriptomics analysis

Citrus cultivation involves the widespread practice of grafting, which has a significant impact on citrus development and fruit quality and yield. However, understanding the effect of flavonoid compounds after different rootstock grafting have been limited. Flavonoid compounds, found at the highest levels in citrus peels, contribute to improving fruit quality and nutritional value. In this study, scion-rootstock interaction was investigated at various developmental stages when sweet orange 'Newhall' was hetero-grafted with two commonly used rootstocks (Poncirus trifoliate population, C. junos Siebold ex Tanaka). Physiological index detection showed a higher concentration of total flavonoid content in peels of sweet orange 'Newhall' grafted on Poncirus trifoliate population (ct) than C. junos Siebold ex Tanaka (cj). Further metabolomic analysis identified 703 flavonoid compounds, including flavones, flavonols, and flavanones. Out of the 25 flavonoids affected by different rootstock grafting and developmental stages, most were flavones. Transcriptomic analysis identified 8,562 differentially expressed genes (DEGs). Co-expression and Pearson's correlation analysis discovered six hub structure genes and 19 transcription factors (TFs) that affected flavonoid biosynthesis. In addition to increasing the transcript levels of genes that synthesize flavones, flavonols, and flavanones, the scion-rootstock interaction also affected the expression of many TFs. Taken together, our findings suggested that hetero-grafting could promote the accumulation of flavonoid compounds in citrus peels during the development stages. These results offered fresh perspectives on grafting's application usefulness and the enhancement of the accumulation of nutritive flavonoid components by grafting in citrus.

[Comparison of growth and quality of wild and cultivated Artemisia stolonifera]

This paper aims to compare the difference of growth and quality between wild and cultivated Artemisia stolonifera, thereby providing references for further development and utilization of A. stolonifera. The wild and cultivated A. stolonifera from different altitudes were collected, and the agronomic characters, moxa yield, volatile components, flavonoids, and phenolic acids were determined. The results showed that the cultivated species were taller and stronger, with more leaves and branches, than the wild species. The moxa yield and combustion quality of wild products were higher than those of cultivated products. The content of main volatile components in cultivated products was higher than that in wild products. The content of flavonoids and phenolic acids in wild products was higher than that in cultivated products. At high altitude, the ignition performance, combustion persistence, comprehensive combustion performance, and heat release during combustion of the wild and cultivated A. stolonifera. were optimal. At middle altitude, the content of main characteristic volatile components and flavone phenolic acids in the leaves of the cultivated and wild A. stolonifera were the highest. At low altitude, the combustion quality and the content of the above components of the cultivated A. stolonifera decrease significantly. Considering the combustion quality and the content of the internal components of the leaf lint, the middle and high altitude areas are suitable for the artificial cultivation of A. stolonifera.

Identification of the Flavone-Inducible Counter-Defense Genes and Their cis-Elements in Helicoverpa armigera

Flavone is widely found in plants and plays an important role in plant defense against pests. Many pests, such as Helicoverpa armigera, use flavone as a cue to upregulate counter-defense genes for detoxification of flavone. Yet the spectrum of the flavone-inducible genes and their linked cis-regulatory elements remains unclear. In this study, 48 differentially expressed genes (DEGs) were found by RNA-seq. These DEGs were mainly concentrated in the retinol metabolism and drug metabolism-cytochrome P450 pathways. Further in silico analysis of the promoter regions of 24 upregulated genes predicted two motifs through MEME and five previously characterized cis-elements including CRE, TRE, EcRE, XRE-AhR and ARE. Functional analysis of the two predicted motifs and two different versions of ARE (named ARE1 and ARE2) in the promoter region of the flavone-inducible carboxylesterase gene CCE001j verified that the two motifs and ARE2 are not responsible for flavone induction of H. armigera counter-defense genes, whereas ARE1 is a new xenobiotic response element to flavone (XRE-Fla) and plays a decisive role in flavone induction of CCE001j. This study is of great significance for further understanding the antagonistic interaction between plants and herbivorous insects.

Semi-Synthesis of Different Pyranoflavonoid Backbones and the Neurogenic Potential

Flavonoids and chalcones are known for their manifold biological activities, of which many affect the central nervous system. Pyranochalcones were recently shown to have a great neurogenic potential, which is partly due to a specific structural motif-the pyran ring. Accordingly, we questioned if other flavonoid backbones with a pyran ring as structural moiety would also show neurogenic potential. Different semi-synthetic approaches starting with the prenylated chalcone xanthohumol, isolated from hops, led to pyranoflavanoids with different backbones. We identified the chalcone backbone as the most active backbone with pyran ring using a reporter gene assay based on the promoter activity of doublecortin, an early neuronal marker. Pyranochalcones therefore appear to be promising compounds for further development as a treatment strategy for neurodegenerative diseases.

Flavone and Hydroxyflavones Are Ligands That Bind the Orphan Nuclear Receptor 4A1 (NR4A1)

It was recently reported that the hydroxyflavones quercetin and kaempferol bind the orphan nuclear receptor 4A1 (NR4A1, Nur77) and act as antagonists in cancer cells and tumors, and they inhibit pro-oncogenic NR4A1-regulated genes and pathways. In this study, we investigated the interactions of flavone, six hydroxyflavones, seven dihydroxyflavones, three trihydroxyflavones, two tetrahydroxyflavones, and one pentahydroxyflavone with the ligand-binding domain (LBD) of NR4A1 using direct-binding fluorescence and an isothermal titration calorimetry (ITC) assays. Flavone and the hydroxyflavones bound NR4A1, and their KD values ranged from 0.36 µM for 3,5,7-trihydroxyflavone (galangin) to 45.8 µM for 3'-hydroxyflavone. KD values determined using ITC and KD values for most (15/20) of the hydroxyflavones were decreased compared to those obtained using the fluorescence assay. The results of binding, transactivation and receptor-ligand modeling assays showed that KD values, transactivation data and docking scores for these compounds are highly variable with respect to the number and position of the hydroxyl groups on the flavone backbone structure, suggesting that hydroxyflavones are selective NR4A1 modulators. Nevertheless, the data show that hydroxyflavone-based neutraceuticals are NR4A1 ligands and that some of these compounds can now be repurposed and used to target sub-populations of patients that overexpress NR4A1.

Enhancement of Neprilysin Activity by Natural Polyphenolic Compounds and Their Derivatives in Cultured Neuroglioma Cells

The onset of Alzheimer's disease (AD) is characterized by accumulation of amyloid β peptide (Aβ) in the brain. Neprilysin (NEP) is one of the major Aβ-degrading enzymes. Given findings that NEP expression in the brain declines from the early stage of AD before apparent neuronal losses are observed, enhancement of NEP activity and expression may be a preventive and therapeutic strategy relevant to disease onset. We screened for compounds that could enhance the activity and expression of NEP using a polyphenol library previously constructed by our research group and investigated the structure-activity relationships of the identified polyphenols. We found that amentoflavone, apigenin, kaempferol, and chrysin enhanced the activity and expression of NEP, suggesting that chemical structures involving a double bond between positions 2 and 3 in the C ring of flavones are important for NEP enhancement, while catechol or pyrogallol structures, except for the galloyl group of catechins, abolished these effects. Moreover, natural compounds, such as quercetin, were not effective per se, but were changed to effective compounds by adding a lipophilic moiety. Using our study findings, we propose improvements for dietary habits with experimental evidence, and provide a basis for the development of novel small molecules as disease-modifying drugs for AD.

Dual-Metal Single Atoms with Dual Coordination for the Domino Synthesis of Natural Flavones

The regulation of coordination configurations of single-atom sites is highly desirable to boost the catalytic performances of SA catalysts. Here, we demonstrate a versatile complexation-deposition strategy for the synthesis of 13 kinds of dual-metal SA site pairs with uniform and exclusive coordination configurations. The preparation is specifically exemplified by the fabrication of Cu and Co single-atom pairs with the co-existence of N and P heteroatoms through etching and pyrolysis of a pre-synthesized metal-organic framework template. Systematic characterizations reveal the uniform and exclusive coordinative configuration of Cu and Co SA sites in CuN₄/CoN₃P₁ and CuN₄/CoN₂P₂, over which the electrons are unsymmetrically distributed. Impressively, the CuN₄/CoN₂P₂ site pairs exhibit significantly enhanced catalytic activity and selectivity in the synthesis of a variety of natural flavonoids in comparison with the CuN₄/CoN₃P₁ and CuN₄/CoN₄ counterparts. Theoretical calculation results suggest that the unsymmetrical electron distribution over the CuN₄/CoN₂P₂ sites could facilitate the adsorption and disassociation of oxygen molecules via reducing the energy barriers of the generation of the key intermediates and thus kinetically accelerate the oxidative-coupling reaction process.

Baicalein Induces G2/M Cell Cycle Arrest Associated with ROS Generation and CHK2 Activation in Highly Invasive Human Ovarian Cancer Cells

Ovarian cancer is a lethal gynecological cancer because drug resistance often results in treatment failure. The CHK2, a tumor suppressor, is considered to be an important molecular target in ovarian cancer due to its role in DNA repair. Dysfunctional CHK2 impairs DNA damage-induced checkpoints, reduces apoptosis, and confers resistance to chemotherapeutic drugs and radiation therapy in ovarian cancer cells. This provides a basis for finding new effective agents targeting CHK2 upregulation or activation to treat or prevent the progression of advanced ovarian cancer. Here, the results show that baicalein (5,6,7-trihydroxyflavone) treatment inhibits the growth of highly invasive ovarian cancer cells, and that baicalein-induced growth inhibition is mediated by the cell cycle arrest in the G₂/M phase. Baicalein-induced G₂/M phase arrest is associated with an increased reactive oxygen species (ROS) production, DNA damage, and CHK2 upregulation and activation. Thus, baicalein modulates the expression of DNA damage response proteins and G₂/M phase regulatory molecules. Blockade of CHK2 activation by CHK2 inhibitors protects cells from baicalein-mediated G₂/M cell cycle arrest. All the results suggest that baicalein has another novel growth inhibitory effect on highly invasive ovarian cancer cells, which is partly related to G₂/M cell cycle arrest through the ROS-mediated DNA breakage damage and CHK2 activation. Collectively, our findings provide a molecular basis for the potential of baicalein as an adjuvant therapeutic agent in the treatment of metastatic ovarian cancer.

Biocomposites of Epoxidized Natural Rubber Modified with Natural Substances

This research aimed to show the possible impact of natural antioxidants on epoxidized natural rubber (ENR) and poly(lactic acid) (PLA) green composites. Thus, the ENR/PLA blends were prepared with the addition of three selected phytochemicals (catechin hydrate, eugenol and flavone). Obtained materials were submitted for solar aging. The analysis of the samples’ features revealed that catechin hydrate is a natural substance that may delay the degradation of ENR/PLA blends under the abovementioned conditions. The blend loaded with catechin hydrate presented stable color parameters (dE < 3 a.u.), the highest aging coefficient (K = 0.38 a.u.) and the lowest carbonyl index based on FT-IR data (CI = 1.56) from among all specimens. What is more, this specimen prolonged the oxidation induction time in comparison with the reference samples. Gathered data prove the efficiency of catechin hydrate as an anti-aging additive. Additionally, it was found that a specimen loaded with flavone changed its color parameters significantly after solar aging (dE = 14.83 a.u.) so that it would be used as an aging indicator. Eventually, presented eco-friendly ENR-based compositions may be applied in polymer technology where materials presenting specific properties are desirable.

In-Vitro, In-Vivo, Molecular Docking and ADMET Studies of 2-Substituted 3,7-Dihydroxy-4H-chromen-4-one for Oxidative Stress, Inflammation and Alzheimer's Disease

Plants' bioactives are well-known safe drugs for vital diseases. Flavones and Flavonoid-rich dietary supplements are known to exhibit neuroprotective potential. In this study, we isolated a flavone 2-(3,4-dimethoxyphenyl)-3,7-dihydroxy-4H-chromen-4-one from Notholirion thomsonianum and it was evaluated against various targets of the oxidative stress-related neurological disorders. The compound showed excellent acetyl and butyrylcholinesterase inhibitions in its profile, giving IC50 values of 1.37 and 0.95 μM, respectively. Similarly, in in-vitro MAO-B assay, our flavone exhibited an IC50 value of 0.14 μM in comparison to the standard safinamide (IC50 0.025 μM). In in-vitro anti-inflammatory assay, our isolated compound exhibited IC50 values of 7.09, 0.38 and 0.84 μM against COX-1, COX-2 and 5-LOX, respectively. The COX-2 selectivity (SI) of the compound was 18.70. The compound was found safe in animals and was very effective in carrageenan-induced inflammation. Due to the polar groups in the structure, a very excellent antioxidant profile was observed in both in-vitro and in-vivo models. The compound was docked into the target proteins of the respective activities and the binding energies confirmed the potency of our compound. Furthermore, absorption, distribution, metabolism, excretion, and toxicity (ADMET) results showed that the isolated flavone has a good GIT absorption ability and comes with no hepatic and cardiotoxicity. In addition, the skin sensitization test, in-vitro human cell line activation test (h-CLAT) and KeratinoSens have revealed that isolated flavone is not skin sensitive with a confidence score of 59.6% and 91.6%. Herein, we have isolated a natural flavone with an effective profile against Alzheimer's, inflammation and oxidative stress. The exploration of this natural flavone will provide a baseline for future research in the field of drug development.

Selenium Application Enhances the Accumulation of Flavones and Anthocyanins in Bread Wheat (Triticum aestivum L.) Grains

Selenium (Se) biofortification in wheat reduces the risk of Se deficiency in humans. Se biofortification increases the concentration of Se and anthocyanins in wheat grains. However, it is unknown whether Se biofortification can enhance flavonoids other than anthocyanins and the mechanism underlying flavonoid accumulation in wheat grains. Here, foliar application of selenite solution in wheat was conducted 10 days after flowering. Metabolite profiling and transcriptome sequencing were performed in Se-treated grains. A significant increase in the total contents of Se, anthocyanins, and flavonoids was observed in Se-treated mature grains. Twenty-seven significantly increased flavonoids were identified in Se-treated immature grains. The significant accumulation of flavones (tricin, tricin derivatives, and chrysoeriol derivatives) was detected, and six anthocyanins, dihydroquercetin (the precursor for anthocyanin biosynthesis) and catechins were also increased. Integrated analysis of metabolites and transcriptome revealed that Se application enhanced the biosynthesis of flavones, dihydroquercetin, anthocyanins, and catechins by increasing the expression levels of seven key structural genes in flavonoid biosynthesis (two TaF3Hs, two TaDFRs, one TaF3'5'H, one TaOMT, and one TaANR). Our findings shed new light on the molecular mechanism underlying the enhancement in flavonoid accumulation by Se supplementation and pave the way for further enhancing the nutritional value of wheat grains.

[Content correlation of eight phenolic acids and flavonoids in different medicinal parts of PA-type Perilla germplasms]

In this study, 10 PA-type Perilla germplasms were selected to detect the content of two phenolic acids, i.e., rosmarinic acid(RA) and caffeic acid(CA), and six flavonoids, including scutellarin-7-O-diglucuronoside(SDG), luteolin-7-O-diglucuronoside(LDG), apigenin-7-O-diglucuronoside(ADG), scutellarin-7-O-glucuroside(SG), luteolin-7-O-glucuroside(LG), and apigenin-7-O-glucuroside(AG) in leaves, stems, and fruits. The total content of phenolic acids and flavonoids in leaves was 3.991-12.028 mg·g~(-1) and 12.309-25.071 mg·g~(-1), respectively, which was much higher than that in stems(0.586-2.015 mg·g~(-1) and 0.879-1.413 mg·g~(-1), respectively) and fruits(0.004-2.222 mg·g~(-1) and 0.651-1.936 mg·g~(-1), respectively). RA was detected in five fruit samples, and RA content between leaves and fruits showed a significant negative correlation in the other five samples. For flavonoids, only LG and LDG could be detected in stems, and SG and SDG were not detected in fruits, while other flavonoids were not detected in some samples. The content of total flavonoids and LG in leaves and fruits was significantly positively correlated, and the content of LG in stems and fruits was significantly positively correlated. In 10 stem samples, seven met the standard that the content of RA in the stem should be not less than 0.1% specified in the Chinese Pharmacopoeia(2020 edition). Only one fruit sample reached the standard of RA content in the fruit not less than 0.25% specified in the Chinese Pharmacopoeia.

Anti-Inflammatory Effects of Cycloheterophyllin on Dinitrochlorobenzene-Induced Atopic Dermatitis in HaCaT Cells and BALB/c Mice

Atopic dermatitis (eczema) is a condition that makes skin red and itchy. Though common in children, the condition can occur at any age. Atopic dermatitis is persistent (chronic) and tends to recur periodically. It may be accompanied by asthma or hay fever. No cure has been found for eczema. Therefore, it is very important to develop ingredients that aid the prevention and treatment of atopic dermatitis. Cycloheterophyllin is derived from Artocarpus heterophyllus and has antioxidant and anti-inflammatory activities. However, it still is not understood whether cycloheterophyllin is an anti-atopic dermatitis agent. Keratinocytes (HaCaT cells) and BALB/c mice for inducing AD-like cutaneous lesions were used to evaluate the potential of cycloheterophyllin as an anti-atopic dermatitis agent. The release of pro-inflammatory cytokines induced by treatment of TNF-α/IFN-γ was reduced after pretreatment with cycloheterophyllin. The inhibitory effects could be a contribution from the effect of the MAP kinases pathway. Moreover, the symptoms of atopic dermatitis (such as red skin and itching) were attenuated by pretreatment with cycloheterophyllin. Epidermal hyperplasia and mast cell infiltration were decreased in the histological section. Finally, damage to the skin barrier was also found to recover through assessment of transepidermal water loss. Taken together, prenylflavone-cycloheterophyllin from Artocarpus heterophyllus is a potential anti-atopic dermatitis ingredient that can be used in preventing or treating the condition.

Combined Metabolome and Transcriptome Analyses Reveal the Flavonoids Changes and Biosynthesis Mechanisms in Different Organs of Hibiseu manihot L

Hibiseu manihot L. (Jinhuakui, JHK), also known as a garden landscape plant, is widely cultivated as a landscape plant having pharmacological effects due to its high flavonoids content. Although flavonoids were the main active pharmaceutical ingredients in JHK, little information was obtained about the content, composition, and accumulation pattern of flavonoids in different tissues. Most studies only identified a few kinds of flavonoids in JHK limited by separation and identification problems. Therefore, combined metabolome and transcriptome analysis was performed to explore the accumulation patterns and biosynthesis mechanisms of flavonoids in JHK. In this study, we identified 160 flavonoids in 15 samples of JHK (flower, leaf, root, stem, and seeds) by using LC-MS/MS. Consistent with the total flavonoid content determination, these flavonoids were significantly accumulated in flowers, followed by leaves, stems, roots, and seeds. Among them, certain flavonoids, with high content, were also identified for the first time in JHK, such as tricetin, catechin, hesperidin, ncyanidin-3-O-sambubioside, astragalin, procyanidin B2/B3/C1, apigenin-5-O-glucoside, etc. Different tissues underwent significantly reprogramming of their transcriptomes and metabolites changes in JHK, particularly in the flavonoid, flavone, and flavonol biosynthesis pathways. We conducted a correlation analysis between RNA-seq and LC-MS/MS to identify the key genes and related flavonoids compounds, rebuild the gene-metabolites regulatory subnetworks, and then identified 15 key genes highly related to flavonoids accumulation in JHK. These key genes might play a fine regulatory role in flavonoids biosynthesis by affecting the gene expression level in different organs of JHK. Our results could be helpful for the improvement of the market/industrial utilization value of different parts of JHK, to pave the way for the regulatory mechanism research of flavonoids biosynthesis, and provide insight for studying the production quality improvement of JHK.

Metabolomics Analysis Revealed the Characteristic Metabolites of Hemp Seeds Varieties and Metabolites Responsible for Antioxidant Properties

Hemp seeds are rich in metabolites such as protein, lipids and flavonoids, which are beneficial to health and can be used as a nutritional supplement. Few studies have focused on the metabolites of different hemp seed varieties. In the current study, using widely targeted metabolomics based on UHPLC-QQQ-MS/MS, we compared the metabolomes of seeds from seven hemp varieties with different uses. A total of 1,001 metabolites, including 201 flavonoids, 86 alkaloids, and 149 phenolic acids, were identified. Flavonoids, organic acids, alkaloids, lipids, and fatty acids with high nutritional value are important to investigate the differences between hemp accessions. By using weighted gene co-expression network analysis (WGCNA), six modules of closely related metabolites were identified. And, we identified the metabolite characteristics and hub metabolites of each variety. Then, we experimentally determined antioxidant activity of seven varieties and demonstrated that alkaloids, flavonoids, phenolic acids, terpenes, and free fatty acids are responsible for the antioxidant activity of hemp seeds. Our research provides useful information for further investigation of the chemical composition of hemp seeds.

Alkyne-Tagged Apigenin, a Chemical Tool to Navigate Potential Targets of Flavonoid Anti-Dengue Leads

A flavonoid is a versatile core structure with various cellular, immunological, and pharmacological effects. Recently, flavones have shown anti-dengue activities by interfering with viral translation and replication. However, the molecular target is still elusive. Here we chemically modified apigenin by adding an alkyne moiety into the B-ring hydroxyl group. The alkyne serves as a chemical tag for the alkyne-azide cycloaddition reaction for subcellular visualization. The compound located at the perinuclear region at 1 and 6 h after infection. Interestingly, the compound signal started shifting to vesicle-like structures at 6 h and accumulated at 24 and 48 h after infection. Moreover, the compound treatment in dengue-infected cells showed that the compound restricted the viral protein inside the vesicles, especially at 48 h. As a result, the dengue envelope proteins spread throughout the cells. The alkyne-tagged apigenin showed a more potent efficacy at the EC₅₀ of 2.36 ± 0.22, and 10.55 ± 3.37 µM, respectively, while the cytotoxicities were similar to the original apigenin at the CC₅₀ of 70.34 ± 11.79, and 82.82 ± 11.68 µM, respectively. Molecular docking confirmed the apigenin binding to the previously reported target, ribosomal protein S9, at two binding sites. The network analysis, homopharma, and molecular docking revealed that the estrogen receptor 1 and viral NS1 were potential targets at the late infection stage. The interactions could attenuate dengue productivity by interfering with viral translation and suppressing the viral proteins from trafficking to the cell surface.

Therapeutic Approach of Flavonoid in Ameliorating Diabetic Cardiomyopathy by Targeting Mitochondrial-Induced Oxidative Stress

Diabetes cardiomyopathy is one of the key factors of mortality among diabetic patients around the globe. One of the prior contributors to the progression of diabetic cardiomyopathy is cardiac mitochondrial dysfunction. The cardiac mitochondrial dysfunction can induce oxidative stress in cardiomyocytes and was found to be the cause of majority of the heart morphological and dynamical changes in diabetic cardiomyopathy. To slow down the occurrence of diabetic cardiomyopathy, it is crucial to discover therapeutic agents that target mitochondrial-induced oxidative stress. Flavonoid is a plentiful phytochemical in plants that shows a wide range of biological actions against human diseases. Flavonoids have been extensively documented for their ability to protect the heart from diabetic cardiomyopathy. Flavonoids' ability to alleviate diabetic cardiomyopathy is primarily attributed to their antioxidant properties. In this review, we present the mechanisms involved in flavonoid therapies in ameliorating mitochondrial-induced oxidative stress in diabetic cardiomyopathy.

The Influence of the Preparation Method on the Physico-Chemical Properties and Catalytic Activities of Ce-Modified LDH Structures Used as Catalysts in Condensation Reactions

Mechanical activation and mechanochemical reactions are the subjects of mechanochemistry, a special branch of chemistry studied intensively since the 19th century. Herein, we comparably describe two synthesis methods used to obtain the following layered double hydroxide doped with cerium, Mg3Al0.75Ce0.25(OH)8(CO3)0.5·2H2O: the mechanochemical route and the co-precipitation method, respectively. The influence of the preparation method on the physico-chemical properties as determined by multiple techniques such as XRD, SEM, EDS, XPS, DRIFT, RAMAN, DR-UV-VIS, basicity, acidity, real/bulk densities, and BET measurements was also analyzed. The obtained samples, abbreviated HTCe-PP (prepared by co-precipitation) and HTCe-MC (prepared by mechanochemical method), and their corresponding mixed oxides, Ce-PP (resulting from HTCe-PP) and Ce-MC (resulting from HTCe-MC), were used as base catalysts in the self-condensation reaction of cyclohexanone and two Claisen-Schmidt condensations, which involve the reaction between an aromatic aldehyde and a ketone, at different molar ratios to synthesize compounds with significant biologic activity from the flavonoid family, namely chalcone (1,3-diphenyl-2-propen-1-one) and flavone (2-phenyl-4H-1benzoxiran-4-one). The mechanochemical route was shown to have indisputable advantages over the co-precipitation method for both the catalytic activity of the solids and the costs.

Citrus flavonoids as potential therapeutic agents: A review

The plants Rutaceae family are known to have contributed a lot toward food and medicine. The most important metabolites of the family are flavonoids. A systematic review was conducted to collect chemical and pharmacological information of flavonoids isolated from family Rutaceae till 2018. A plethora of flavonoids have been isolated and studied systematically for various bioactivities, including anticancer, antibacterial, antiviral, analgesic, antioxidant, antidiabetic, antiinflammatory, in bronchitis, ulcers, and so on. The important groups of flavonoids isolated are naringin, poncirin, rhoifolin, marmesin, hesperidin, tangeretin, nobiletin, glychalcone, glyflavanone, lemairone, acacetin 3,6-di-C-glucoside, vicenin-2, lucenin-2 4'-methyl ether, narirutin 4'-O-glucoside, apigenin 8-C-neohesperidoside, phloretin 3',5'-di-C-glucoside, rutin, rhamnetin, dihydrokaempferol, dihydrokaempferol 3-O-rhamnoside (engeletin) and kaempferol, excavaside A and B, myricetin 3-O-β-D-rutinoside, myricetin 3,3'-di-α-l-rhamnopyranoside, myricetin 3'-α-l-rhamnopyranoside, and others. The flavonoids isolated from the citrus family need to be considered from a nutraceutical, therapeutic, and pharmaceutical point of view for future medicine.

Nobiletin-induced partial abrogation of deleterious effects of AKT inhibition on preimplantation bovine embryo development in vitro

During preimplantational embryo development, PI3K/AKT regulates cell proliferation and differentiation and nobiletin modulates this pathway to promote cell survival. Therefore, we aimed to establish whether, when the AKT cascade is inhibited using inhibitors III and IV, nobiletin supplementation to in vitro culture media during the minor (2 to 8-cell stage, MNEGA) or major (8 to 16-cell stage, MJEGA) phases of EGA is able to modulate the development and quality of bovine embryos. In vitro zygotes were cultured during MNEGA or MJEGA phase in SOF + 5% FCS or supplemented with: 15 μM AKT-InhIII; 10 μM AKT-InhIV; 10 μM nobiletin; nobiletin+AKT-InhIII; nobiletin+AKT-InhIV; 0.03% DMSO. Embryo development was lower in treatments with AKT inhibitors, while combination of nobiletin with AKT inhibitors was able to recover their adverse developmental effect and also increase blastocyst cell number. The mRNA abundance of GPX1, NFE2L2, and POU5F1 was partially increased in 8- and 16-cell embryos from nobiletin with AKT inhibitors. Besides, nobiletin increased the p-rpS6 level whether or not AKT inhibitors were present. In conclusion, nobiletin promotes bovine embryo development and quality and partially recovers the adverse developmental effect of AKT inhibitors which infers that nobiletin probably uses another signalling cascade that PI3K/AKT during early embryo development in bovine.

Anti-Inflammatory and Anti-Allergic Effects of Saponarin and Its Impact on Signaling Pathways of RAW 264.7, RBL-2H3, and HaCaT Cells

Saponarin{5-hydroxy-2-(4-hydroxyphenyl)-6-[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]-7-[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxychromen-4-one}, a flavone found in young green barley leaves, is known to possess antioxidant, antidiabetic, and hepatoprotective effects. In the present study, the anti-inflammatory, anti-allergic, and skin-protective effects of saponarin were investigated to evaluate its usefulness as a functional ingredient in cosmetics. In lipopolysaccharide-induced RAW264.7 (murine macrophage) cells, saponarin (80 μM) significantly inhibited cytokine expression, including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, inducible nitric oxide synthase, and cyclooxygenase (COX)-2. Saponarin (80 μM) also inhibited the phosphorylation of extracellular signal-regulated kinase (ERK) and p38 involved in the mitogen-activated protein kinase signaling pathway in RAW264.7 cells. Saponarin (40 μM) significantly inhibited β-hexosaminidase degranulation as well as the phosphorylation of signaling effectors (Syk, phospholipase Cγ1, ERK, JNK, and p38) and the expression of inflammatory mediators (tumor necrosis factor [TNF]-α, IL-4, IL-5, IL-6, IL-13, COX-2, and FcεRIα/γ) in DNP-IgE- and DNP-BSA-stimulated RBL-2H3 (rat basophilic leukemia) cells. In addition, saponarin (100 μM) significantly inhibited the expression of macrophage-derived chemokine, thymus and activation-regulated chemokine, IL-33, thymic stromal lymphopoietin, and the phosphorylation of signaling molecules (ERK, p38 and signal transducer and activator of transcription 1 [STAT1]) in TNF-α- and interferon (IFN)-γ-stimulated HaCaT (human immortalized keratinocyte) cells. Saponarin (100 μM) also significantly induced the expression of hyaluronan synthase-3, aquaporin 3, and cathelicidin antimicrobial peptide (LL-37) in HaCaT cells, which play an important role as skin barriers. Saponarin remarkably inhibited the essential factors involved in the inflammatory and allergic responses of RAW264.7, RBL-2H3, and HaCaT cells, and induced the expression of factors that function as physical and chemical skin barriers in HaCaT cells. Therefore, saponarin could potentially be used to prevent and relieve immune-related skin diseases, including atopic dermatitis.

Acroflavone A, a new prenylated flavone from the fruit of Acronychia pedunculata (L.) Miq

Phytochemical investigation of the fruit of Acronychia pedunculata (L.) Miq. led to the isolation of a new prenylated flavone, acroflavone A (1), together with eight known compounds (2-9). Their structures were elucidated by thorough analysis of mass spectrometric and NMR spectroscopic data. The isolated compounds were evaluated against several bacterial strains. Three known compounds (3-5) demonstrated antibacterial activities. Among them, acrovestone (5) proved equally or more potent than chloramphenicol against three out of the four strains tested.

The Potential Role of Flavonoids in Ameliorating Diabetic Cardiomyopathy via Alleviation of Cardiac Oxidative Stress, Inflammation and Apoptosis

Diabetic cardiomyopathy is one of the major mortality risk factors among diabetic patients worldwide. It has been established that most of the cardiac structural and functional alterations in the diabetic cardiomyopathy condition resulted from the hyperglycemia-induced persistent oxidative stress in the heart, resulting in the maladaptive responses of inflammation and apoptosis. Flavonoids, the most abundant phytochemical in plants, have been reported to exhibit diverse therapeutic potential in medicine and other biological activities. Flavonoids have been widely studied for their effects in protecting the heart against diabetes-induced cardiomyopathy. The potential of flavonoids in alleviating diabetic cardiomyopathy is mainly related with their remedial actions as anti-hyperglycemic, antioxidant, anti-inflammatory, and anti-apoptotic agents. In this review, we summarize the latest findings of flavonoid treatments on diabetic cardiomyopathy as well as elucidating the mechanisms involved.

Nervione, a new benzofuran derivative from Nervilia concolor

A new benzofuran derivative, nervione (1), was isolated from Nervilia concolor (Blume) Schltr. (Orchidaceae). Eight previously reported compounds were also isolated: 5,7-dimethoxyflavone (2), 3,5,7-trimethoxyflavone (3), 7-methoxyflavone (4), 3,7-dimethoxy-5-hydroxyflavone (5), tetramethylscutellarein (4',5,6,7-tetramethoxyflavone) (6), 5,7-dimethoxy-4'-hydroxyflavone (7), rhamnetin (8), and 5,7-dihydroxy-3',4'-dimethoxyflavone (9). The structures were elucidated by 1D, 2D NMR, and HRESIMS spectroscopy in addition to the literature. The relative configuration of 1 was defined using DP4+ probability while its absolute configuration was defined by comparison of the ECD spectrum of 1 with those of previously reported compounds. All isolated compounds were evaluated for alpha-glucosidase inhibition, revealing weak or no activity.

Study on the structure and digestibility of high amylose Tartary buckwheat (Fagopyrum tataricum Gaertn.) starch-flavonoid prepared by different methods

Tartary buckwheat (Fagopyrum tataricum Gaertn.) is the only food rich in flavonoid bioactive substances in grains. Studies have shown that flavonoids interaction with amylose has an important impact on the physical and chemical properties and structure of starch. In this study, Tartary buckwheat was used as a raw material. It was then threshed with pullulanase, and a high amylose Tartary buckwheat starch flavonoid complex (HBS/BF) was prepared by physical mixing (PM), water bath treatment (WT), acid-base precipitation (AP), microwave treatment (MT), and ultrasonic treatment (UT); the physical and chemical properties were then evaluated. The results show that HBS/BF-UT and HBS/BF-MT have a higher iodine binding rate than HBS/BF-PM; X-ray diffraction results show that HBS/BF-AP has a V-type crystal form, but the relative crystallinity was reduced. Fourier infrared spectroscopy showed that there is no new covalent bond between Tartary buckwheat starch and flavonoids. In vitro digestion showed that adding flavonoid significantly increased the digestibility of Tartary buckwheat starch. PRACTICAL APPLICATION: These results will provide a theoretical basis for further starch anti-digestion mechanisms and the preparation of resistant starch. These steps will provide insights into the application of Tartary buckwheat starch and flavonoids in the food industry.

Three AP2/ERF family members modulate flavonoid synthesis by regulating type IV chalcone isomerase in citrus

Flavanones and flavones are excellent source of bioactive compounds but the molecular basis of their highly efficient production remains elusive. Chalcone isomerase (CHI) family proteins play essential roles in flavonoid biosynthesis but little are known about the transcription factors controlling their gene expression. Here, we identified a type IV CHI (designated as CitCHIL1) from citrus which enhances the accumulation of citrus flavanones and flavones (CFLs). CitCHIL1 participates in a CFL biosynthetic metabolon and assists the cyclization of naringenin chalcone to (2S)-naringenin, which leads to the efficient influx of substrates to chalcone synthase (CHS) and improves the catalytic efficiency of CHS. Overexpressing CitCHIL1 in Citrus and Arabidopsis significantly increased flavonoid content and RNA interference-induced silencing of CitCHIL1 in citrus led to a 43% reduction in CFL content. Three AP2/ERF transcription factors were identified as positive regulators of the CitCHIL1 expression. Of these, two dehydration-responsive element binding (DREB) proteins, CitERF32 and CitERF33, activated the transcription by directly binding to the CGCCGC motif in the promoter, while CitRAV1 (RAV: related to ABI3/VP1) formed a transcription complex with CitERF33 that strongly enhanced the activation efficiency and flavonoid accumulation. These results not only illustrate the specific function that CitCHIL1 executes in CFL biosynthesis but also reveal a new DREB-RAV transcriptional complex regulating flavonoid production.

Flavone-Rich Fractions and Extracts from Oroxylum indicum and Their Antibacterial Activities against Clinically Isolated Zoonotic Bacteria and Free Radical Scavenging Effects

Oroxylum indicum extracts from the seeds collected from Lampang and Pattani provinces in Thailand, and young fruits and flowers exhibited in vitro display antioxidant and antibacterial activities against clinically isolated zoonotic bacteria including Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, β-hemolytic Escherichia coli and Staphylococcus aureus. The orange crystals and yellow precipitates were obtained from the preparation processes of the seed extracts. The orange-red crystals from the seeds collected from Lampang province exhibited strong in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effects (EC50 value = 25.99 ± 3.30 μg/mL) and antibacterial effects on S. intermedius and β-hemolytic E. coli while the yellow precipitate from the same source exhibited only antioxidant activity. Quantitative analysis of phytochemicals in O. indicum samples by spectrophotometric and HPLC techniques showed that they contained different amounts of total phenolic, total flavonoid and three major flavones; baicalin, baicalein and chrysin contents. Young fruit extract, which contained low amounts of flavone contents, still promoted antibacterial effects against the tested bacteria with IC50 values lower than 1 mg/mL and MIC values between 4 to 10 mg/mL in S. intermedius, S. aureus and S suis while higher IC50 and MIC values against P. aeruginosa and β-hemolytic E. coli were found. From scanning electron microscopy, the extract of the young fruit of O. indicum promoted morphological changes in the bacterial cells by disrupting the bacterial cell walls, inducing leakage of the cellular content, and generating the abnormal accumulation of cells. The mechanism of action of the extract for this antibacterial effect may be the disruption of the cell membrane and abnormal cell aggregations. Regression analysis of the results suggests the correlation between total phenolic and total flavonoid contents and antioxidant and antibacterial effects. Baicalin was found to have a high correlation with an inhibitory effect against β-hemolytic E. coli while three unidentified peaks, which could be flavones, showed high correlations with an inhibitory effect against S. intermedius, S. suis, P. aeruginosa and S. aureus.

Developmental Stage Determines the Accumulation Pattern of UV-Absorbing Compounds in the Model Liverwort Marchantia polymorpha subsp. ruderalis under Controlled Conditions

The liverwort Marchantia polymorpha subsp. ruderalis is an emerging model plant, and some data are available on its responses to ultraviolet (UV) radiation. However, it is unknown if the developmental stage of the thalli modulates the effects of UV radiation on the contents of potentially protecting phenolic compounds. To fill this gap, liverwort samples were exposed or non-exposed to UV radiation for 38 days under controlled conditions, using three developmental stages: gemmae (G), one-month thalli (T1), and two-month thalli (T2). Then, the bulk level of methanol-soluble UV-absorbing compounds and the contents of six flavones (apigenin and luteolin derivatives) were measured. The UV responsiveness decreased with thallus age: G and T1 plants were the most UV-responsive and showed a strong increase in all the variables, with G plants more responsive than T1 plants. In UV-exposed T2 plants, only apigenin derivatives increased and more modestly, probably due to a lower acclimation capacity. Nevertheless, the thalli became progressively tougher due to a decreasing water content, representing a possible structural protection against UV. In UV-exposed plants, the temporal patterns of the accumulation of phenolic compounds were compound-specific. Most compounds decreased with thallus age, but di-glucuronide derivatives showed a bell-shaped pattern, with T1 plants showing the highest contents. A Principal Components Analysis (PCA) ordination of the different samples summarized the results found. The patterns described above should be taken into account to select thalli of an adequate developmental stage for experiments investigating the induction of phenolic compounds by UV radiation.

The Regulation of Adaptation to Cold and Drought Stresses in Poa crymophila Keng Revealed by Integrative Transcriptomics and Metabolomics Analysis

Poa crymophila Keng is highly adaptable to long-term low temperature and drought conditions, making it a desirable foraging grass of the Qinghai-Tibet Plateau. Here, the widely targeted metabolomics and comparative transcriptome analyses were utilized for the discovery of metabolites and genes in P. crymophila in response to cold and drought stresses. P. crymophila were exposed to -5°C for 24 h and recovered to 22°C for 48 h, as well as drought for 10 days followed by re-watering for 1 day. In total, 779 metabolic features were assigned to metabolites and 167,845 unigenes were generated. Seventeen compounds showed significant up-regulation (variable importance in project >1) under both stresses in the metabolic profiling, mainly annotated as carbohydrates, flavones, and phenylpropanoids. The genes which were positively correlated with these metabolites were assigned to pathways (sucrose-starch, raffinose, phenylpropanoid, and flavone metabolism) using the Mapman software package. Alpha-amylase, beta-fructofuranosidase, and sugar transport genes degraded the glucose and starch to small molecule sugars for the purpose of osmotic adjustment and to provide more energy for the growth of P. crymophila in an adverse environment. The induction of cinnamoyl-CoA reductase (CCR) and the MYB gene as well as the sharp increase in schizandrin, a kind of lignan, showed that this likely has the closest connection with the tolerance to both stresses. Four significantly induced flavone compounds are probably involved in reducing oxidative damage. Our results indicated that activation of the phenlypropanoid pathway plays the primary role in P. crymophila adapting to harsh environments. This study showed the mechanism of P. crymophila responding to both cold and drought stresses and showed the discovery of a new biological regulator against stresses.

[Study advance in biosynthesis of flavone from Scutellaria]

Flavones are widely distributed in terrestrial plants and act as important bioactive compounds in medicinal plants. Baicalein, wogonin and their glycosides baicalin and wogonoside are major active components found in medicinal plant Scutellaria baicalensis. These flavones can induce apoptosis in various cancer cell lines, with such pharmacological activities as anti-oxidation, antivirus and liver protection. In recent years, the biosynthesis pathways of flavones in Scutellaria have been studied thoroughly. In particular, the biosynthesis pathways of baicalein and wogonin in S. baicalensis were interpreted completely. In this review, the biosynthesis of flavones in Scutellaria, the regulation of environmental factors and elicitors on their biosynthesis, and the metabolic engineering of the flavones were discussed.

The Callus of Phaseolus coccineus and Glycine max Biotransform Flavanones into the Corresponding Flavones

In vitro plant cultures are gaining in industrial importance, especially as biocatalysts and as sources of secondary metabolites used in pharmacy. The idea that guided us in our research was to evaluate the biocatalytic potential of newly obtained callus tissue towards flavonoid compounds. In this publication, we describe new ways of using callus cultures in the biotransformations. In the first method, the callus cultures grown on a solid medium are transferred to the water, the reaction medium into which the substrate is introduced. In the second method, biotransformation is carried out on a solid medium by growing callus cultures. In the course of the research, we have shown that the callus obtained from Phaseolus coccineus and Glycine max is capable of converting flavanone, 5-methoxyflavanone and 6-methoxyflavanone into the corresponding flavones.

[Chemical profiling of Artemisia rupestris using HPLC-IT-TOF-MS]

Artemisia rupestris is widely used as a folk medicine of Uygur and Kazak with blood and detoxification, deaccumulation stagnation, clearing heat digestion and other effects. Currently, the chemical profile of A. rupestris has not been disclosed, resulting in a great obstacle for the systematic clarification of the efficacy materials and the quality evaluations. In this paper, HPLC-IT-TOF-MS was deployed to characterize the chemical constituents in A. rupestris. As a result, a total of 124 compounds were detected in 75% ethanol extract of A. rupestris. By comparing with the reference compounds, seven chlorogenic acids, and four flavonoids as well as one sesquiterpenoid were definitely identified. Moreover, twenty sesquiterpenes, sixty-five flavonoids and twenty-three chlorogenic acids were preliminarily identified by matching MS/MS spectral information with literature data and applying those empirical mass spectrometric cracking rules. In current study, the chemical composition of A. rupestris was profiled in depth, and the findings are envisioned to provide a theoretical basis for the further studies of this well-known herbal medicine, such as efficacy material characterization and quality assessment.

Flavone as a novel matrix for the matrix-assisted laser desorption/ionisation analysis of lanthanide and transition metal salts

The mass spectral analysis of metal salts, especially lanthanide and transition metal salts, can be challenging. Although getting information on the metal present is usually straightforward, obtaining information on the correct oxidation state and anion composition is challenging. Many ionisation techniques have some redox component to the ionisation process, which commonly results in changing the oxidation state of the metal and the associated loss of ligand and anion information. We present here a simple method for negative ion matrix-assisted laser desorption/ionisation mass spectrometry using the non-acidic flavonoid flavone as a novel matrix. This results in reliable information on the oxidation state of the metal as spectra are dominated by anion adduct ions with very little (typically no) redox processes occurring.

Synthesis, In Silico and In Vitro Evaluation of Some Flavone Derivatives for Acetylcholinesterase and BACE-1 Inhibitory Activity

Acetylcholinesterase (AChE) and β-secretase (BACE-1) have become attractive therapeutic targets for Alzheimer’s disease (AD). Flavones are flavonoid derivatives with various bioactive effects, including AChE and BACE-1 inhibition. In the present work, a series of 14 flavone derivatives was synthesized in relatively high yields (35–85%). Six of the synthetic flavones (B4, B5, B6, B8, D6 and D7) had completely new structures. The AChE and BACE-1 inhibitory activities were tested, giving pIC₅₀ 3.47–4.59 (AChE) and 4.15–5.80 (BACE-1). Three compounds (B3, D5 and D6) exhibited the highest biological effects on both AChE and BACE-1. A molecular docking investigation was conducted to explain the experimental results. These molecules could be employed for further studies to discover new structures with dual action on both AChE and BACE-1 that could serve as novel therapies for AD.

A Natural Flavone Tricin from Grains Can Alleviate Tumor Growth and Lung Metastasis in Colorectal Tumor Mice

Tricin, a flavone isolated from rice bran, has been shown to be chemopreventive in a colorectal cancer (CRC) mouse model. This study aimed to illustrate the inhibitory activities of tricin in colon cancer cells and in a metastatic CRC mouse model. BALB/c mice injected with mouse Colon26-Luc cells into the rectum wall were treated with tricin (37.5 mg/kg) daily for 18 days. Orthotopic colon tumor growth and metastasis to lungs were assessed by in vivo bioluminescence imaging. Results showed that tricin suppressed Colon-Luc cells motility and downregulated phosphorylated Akt, Erk1/2 and NF-κB expressions of human colon cancer HT-29 cells. While tricin treatment suppressed tumor growth and lung metastasis as well as altered the populations of myeloid-derived suppressor cells and regulatory T cells in spleens. In summary, the tumor microenvironment modulatory and anti-metastatic effects of tricin in colon cancer mouse model were shown for the first time, suggesting the potential development of tricin-containing food supplements for CRC patients.

A Flavone-Based Solvatochromic Probe with A Low Expected Perturbation Impact on the Membrane Physical State

The study of the cell membrane is an ambitious and arduous objective since its physical state is regulated by a series of processes that guarantee its regular functionality. Among the different methods of analysis, fluorescence spectroscopy is a technique of election, non-invasive, and easy to use. Besides, molecular dynamics analysis (MD) on model membranes provides useful information on the possibility of using a new probe, following its positioning in the membrane, and evaluating the possible perturbation of the double layer. In this work, we report the rational design and the synthesis of a new fluorescent solvatochromic probe and its characterization in model membranes. The probe consists of a fluorescent aromatic nucleus of a 3-hydroxyflavone moiety, provided with a saturated chain of 18 carbon atoms and a zwitterionic head so to facilitate the anchoring to the polar heads of the lipid bilayer and avoid the complete internalization. It was possible to study the behavior of the probe in GUV model membranes by MD analysis and fluorescence microscopy, demonstrating that the new probe can efficiently be incorporated in the lipid bilayer, and give a color response, thanks to is solvatochromic properties. Moreover, MD simulation of the probe in the membrane supports the hypothesis of a reduced perturbation of the membrane physical state.

Effects of Apigenin on RBL-2H3, RAW264.7, and HaCaT Cells: Anti-Allergic, Anti-Inflammatory, and Skin-Protective Activities

Apigenin (4',5,7-trihydroxyflavone, flavonoid) is a phenolic compound that is known to reduce the risk of chronic disease owing to its low toxicity. The first study on apigenin analyzed its effect on histamine release in the 1950s. Since then, anti-mutation and antitumor properties of apigenin have been widely reported. In the present study, we evaluated the apigenin-mediated amelioration of skin disease and investigated its applicability as a functional ingredient, especially in cosmetics. The effect of apigenin on RAW264.7 (murine macrophage), RBL-2H3 (rat basophilic leukemia), and HaCaT (human immortalized keratinocyte) cells were analyzed. Apigenin (100 μM) significantly inhibited nitric oxide (NO) production, cytokine expression (interleukin (IL)-1β, IL6, cyclooxygenase (COX)-2, and inducible nitric oxide synthase [iNOS]), and phosphorylation of mitogen-activated protein kinase (MAPK) signal molecules, including extracellular signal-regulated kinase (ERK) and c-Jun N-terminal protein kinase (JNK) in RAW264.7 cells. Apigenin (30 M) also inhibited the phosphorylation of signaling molecules (Lyn, Syk, phospholipase Cγ1, ERK, and JNK) and the expression of high-affinity IgE receptor FcεRIα and cytokines (tumor necrosis factor (TNF)-α, IL-4, IL-5, IL-6, IL-13, and COX-2) that are known to induce inflammation and allergic responses in RBL-2H3 cells. Further, apigenin (20 μM) significantly induced the expression of filaggrin, loricrin, aquaporin-3, hyaluronic acid, hyaluronic acid synthase (HAS)-1, HAS-2, and HAS-3 in HaCaT cells that are the main components of the physical barrier of the skin. Moreover, it promoted the expression of human β-defensin (HBD)-1, HBD-2, HBD-3, and cathelicidin (LL-37) in HaCaT cells. These antimicrobial peptides are known to play an important role in the skin as chemical barriers. Apigenin significantly suppressed the inflammatory and allergic responses of RAW264.7 and RBL cells, respectively, and would, therefore, serve as a potential prophylactic and therapeutic agent for immune-related diseases. Apigenin could also be used to improve the functions of the physical and chemical skin barriers and to alleviate psoriasis, acne, and atopic dermatitis.

Ethylene mediates the branching of the jasmonate-induced flavonoid biosynthesis pathway by suppressing anthocyanin biosynthesis in red Chinese pear fruits

Flavonoid accumulation in most fruits is enhanced by ethylene and jasmonate. However, little is known about the hormone functions related to red pear fruit coloration or their combined effects and potential underlying mechanisms. Various treatments were used to investigate the flavonoid metabolite profile and pear transcriptome to verify the effects of ethylene and jasmonate on flavonoid biosynthesis in red pear fruits as well as the mechanism behind this. Ethylene inhibits anthocyanin biosynthesis in red Chinese pear fruits, whereas jasmonate increases anthocyanin and flavone/isoflavone biosyntheses. The branching of the jasmonate-induced flavonoid biosynthesis pathway is determined by ethylene. Co-expression network and Mfuzz analyses revealed 4,368 candidate transcripts. Additionally, ethylene suppresses PpMYB10 and PpMYB114 expression via TF repressors, ultimately decreasing anthocyanin biosynthesis. Jasmonate induces anthocyanin accumulation through transcriptional or post-translational regulation of TFs-like MYB and bHLH in the absence of ethylene. However, jasmonate induces ethylene biosynthesis and the associated signalling pathway in pear, thereby decreasing anthocyanin production, increasing the availability of the precursors for flavone/isoflavone biosynthesis and enhancing deep yellow fruit coloration. We herein present new phenotypes and fruit coloration regulatory patterns controlled by jasmonate and ethylene, and confirm that the regulation of fruit coloration is complex.

[In silico Screening of Flavones and its Derivatives as Potential Inhibitors of Quorum-Sensing Regulator LasR of Pseudomonas aeruginosa]

Antibiotic resistance is a global problem nowadays and in 2017 the World Health Organization published the list of bacteria for which treatment are urgently needed, where Pseudomonas aeruginosa is of critical priority. Current therapies lack efficacy because this organism creates biofilms conferring increased resistance to antibiotics and host immune responses. The strategy is to "not kill, but disarm" the pathogen and resistance will be developed slowly. It has been shown that LasI/LasR system is the main component of the quorum sensing system in P. aeruginosa. LasR is activated by the interaction with its native autoinducer. A lot flavones and their derivatives are used as antibacterial drug compounds. The purpose is to search compounds that will inhibit LasR. This leads to the inhibition of the synthesis of virulence factors thus the bacteria will be vulnerable and not virulent. We performed virtual screening using AutoDock Vina, rDock, LeDock for obtaining consensus predictions. The results of virtual screening suggest benzamides which are synthetical derivatives of flavones as potential inhibitors of transcriptional regulator LasR. These are consistent with recently published experimental data, which demonstrate the high antibacterial activity of benzamides. The compounds interact with the ligand binding domain of LasR with higher binding affinity than with DNA binding domain. Among the selected compounds, by conformational analysis, it was found that there are compounds that bind to the same amino acids of ligand binding domain as the native autoinducer. This could indicate the possibility of competitive interaction of these compounds. A number of compounds that bind to other conservative amino acids ligand binding domain have also been discovered, which will be of interest for further study. Selected compounds meet the criteria necessary for their consideration as drugs and can serve as a basis for conducting further in vitro/in vivo experiments. It could be used for the development of modern anti-infective therapy based on the quorum sensing system of P. aeruginosa.

Rosemary Diterpenes and Flavanone Aglycones Provide Improved Genoprotection against UV-Induced DNA Damage in a Human Skin Cell Model

Overexposure to solar ultraviolet (UV) radiation is the major cause of a variety of cutaneous disorders, including sunburn, photoaging, and skin cancers. UVB radiation (290–320 nm) causes multiple forms of DNA damage, p53 induction, protein and lipid oxidation, and the generation of harmful reactive oxygen species (ROS). In recent years, botanicals containing polyphenols with antioxidant and anti-inflammatory properties as skin photoprotective agents have emerged. This study evaluated the protective effects of two formulations against UVB-induced damage in a skin cell model. One of the formulations (F2) contained a combination of citrus and olive extracts and the other one (F1) also contained a rosemary extract. The antioxidant capacity of both formulations was estimated by different in vitro methods, and the cell viability, intracellular ROS generation, mitochondrial depolarization, and DNA damage were studied in UVB-irradiated human keratinocytes. Both formulations exerted photoprotective effects on skin cells and decreased mitochondrial depolarization and DNA damage. F1 which contained iridoids, rosemary diterpenes, glycosides and aglycones of citrus flavanones, and monohydroxylated flavones exhibited higher cellular photoprotective effects and mitochondrial membrane potential restoration, as well as an enhanced capacity to decrease DNA double strand breaks and the DNA damage response. In contrast, F2, which contained mostly iridoids, citrus flavanone aglycones, and mono- and dihydroxylated flavones, exhibited a higher capacity to decrease intracellular ROS generation and radical scavenging capacity related to metal ion chelation. Both formulations showed a similar capability to decrease the number of apoptotic cells upon UVB radiation. Based on our results and those of others, we postulate that the stronger capacity of F1 to protect against UVB-induced DNA damage in human keratinocytes is related to the presence of rosemary diterpenes and citrus flavanone aglycones. Nevertheless, the presence of the dihydroxylated flavones in F2 may contribute to inhibiting the generation of metal-related free radicals. To confirm the efficacy of these formulations as potential candidates for oral/topical photoprotection, human trials are required to circumvent the limitations of the cellular model.