Flavonols Quercetin Research Articles

Genomic footprint of evolution of eusociality in bees: floral food use and CYPome “blooms”

Comparative analyses of genomes of ten bee species representing different degrees of social complexity have demonstrated that independent transitions to eusociality are often accompanied by or lead to expansions or contractions of gene families (albeit different families across independent lineages). Because collective gathering, processing, and storage of plant products is a hallmark of bee social complexity, we examined the genomic inventory of cytochrome P450 genes (the CYPome) in these ten genomes, to search for footprints of eusociality in phytochemical detoxification pathways and, using a Bayesian implementation of the McDonald–Kreitman test, evidence of adaptive evolution within P450 lineages associated with food processing in eusocial florivorous Bombus and Apis species versus eusocial carnivorous Polistes species.We found no patterns linking CYPome size to level of social complexity within the ten bee genomes at the gene family level; however, a pattern emerged at the subfamily level, with the CYP6AS subfamily most diverse in perennial eusocial resin-collecting bees. In Apis mellifera, several CYP6AS enzymes are known to metabolize flavonols, ubiquitous constituents of nectar and honey, pollen and beebread, and resins and propolis. CYP6AS subfamily size varies from 7 in the solitary Habropoda laboriosa and the facultatively eusocial Lasioglossum albipes to 17 in the perennial eusocial Melipona quadrifasciatus; the degree of sociality across the ten species is correlated with CYP6AS inventory size (Spearman’s rho = 0.704, p < 0.023). Remarkably, there is perfect overlap between CYP6AS genes upregulated by the flavonol quercetin in A. mellifera and CYP6AS genes with signs of adaptive evolution in either Apis or Bombus. Our finding of positive selection on CYP6AS genes in Apis and Bombus, but not Polistes supports the hypothesis that CYP6AS subfamily expansion was involved in facilitating the shift from carnivory to florivory in bees. That some CYP6AS enzymes metabolize flavonoids suggests that subfamily expansion results from increased evolutionary exposure to these phytochemicals, through concentration of nectar into honey, pollen into beebread, and plant resins into propolis. Accompanying the evolutionary progression from solitary to perennial eusocial behavior in bees is a transition from short-term storage of ephemeral low-quality resources to concentrating and stockpiling those resources for colony use, with a concomitant need for phytochemical detoxification.

Antioxidant properties and anti-quorum sensing potential of Carum copticum essential oil and phenolics against Chromobacterium violaceum

The chemical composition, antimicrobial and antioxidant properties of Carum copticum essential oil and its methanolic extract were investigated. Thirteen compounds were identified representing 99.3% of the total oil composition. Oxygenated monoterpenes (53.0%) dominated the C. copticum essential oil with high contents of thymol (51.7 ± 1.51%), p-cymene (26.9 ± 1.11%), γ-terpinene (16.7 ± 0.76%), and β-pinene (1.6 ± 0.15%). In the methanolic extract, the caffeic, gallic, chlorogenic, coumaric and ferulic acids, flavan-3-ols (catechin), flavone (hyperoside), and the flavonol quercetin were identified. Antimicrobial activity of essential oil and the organic extract was tested by disk diffusion and broth microdilution method. The essential oil was effective against the tested bacteria and yeast strains with the highest activity and the MICs and MBCs values were lower as compared to the methanolic extract. The essential oil showed anti-quorum sensing activity against Chromobacterium violaceum, and the IC50 value for violacein inhibition was 0.23mg/ml. Both the essential oil and the methanolic extract also showed antioxidant activities. The results obtained highlight the potential use of C. copticum as a possible source of antimicrobial and antioxidant compounds to be used both as food flavor and as a broad spectrum antibiotic.

Application of a Stopped-Flow EPR Method for the Detection of Short-Lived Flavonoid Semiquinone Radicals Produced by Oxidation Using 15N-Labeled Nitrosodisulfonate Radical (Fremy’s Salt)

A stopped-flow-electron paramagnetic resonance (EPR) method was applied for the detection of short-lived radicals of flavonoids bearing a catechol moiety as the B-ring, such as flavonols (quercetin, fisetin, and rutin), flavanones (eriodictyol and taxifolin), flavanols (catechin and epicatechin), and flavone (luteolin). 15N-labeled sodium salt of nitrosodisulfonate (15NDS) was employed to obtain the highly resolved EPR hyperfine structure (hfs) of flavonoid-derived semiquinone radicals under stoichiometrically regulated reaction conditions in aqueous media (pH 10). The EPR hfs of these flavonoids radicals, except catechin and epicatechin, were recorded. Based on the g value and the proton hyperfine coupling constants (hfcc), these flavonoid-derived radicals were assigned to be semiquinone radicals of the catechol moiety (B-ring). For example, the observed EPR hyperfine structure (hfs) of the luteolin radical (Lut−·) was composed of four sets of doublet splitting, which could be ascribed to the three protons of the B-ring (a2′ = 0.136, a5′ = 0.102, and a6′ = 0.272 mT) and a vinyl proton of the C-ring (a3 = 0.099 mT). In addition, the characteristically small doublet splitting resolved for the fisetin anion radical (Fis−·, 0.028 mT) was assigned to the aromatic proton at the C5 carbon of the A-ring, indicating that the unpaired electron of the radials was partially delocalized onto the A-ring through the π bonds involved in the vinyl-carbonyl moiety of the C-ring. The hfcc of the methine protons at the C2 carbon of taxifolin and eriodictyol-derived radicals (Tax−· and Eri−·) was, respectively, evaluated to be 0.102 and 0.230 mT. The assignment of the proton hfcc of flavonoid-derived semiquinone radicals will be discussed in relation with the molecular structure of the C-ring.

LOCALIZATION AND ORIENTATION OF METHOXY FLAVONOIDS IN DPPC BILAYERS: EFFECT ON THEIR ANTI-PROLIFERATIVE ACTIVITY

Objective: Flavones and flavonols are an important class of naturally occurring flavonoids. They are well known for their pharmacological activity. This activity is associated with the ability of flavones and flavonols to influence membrane–dependent processes. In this paper, we have reported localization, orientation and interaction, of four synthesized flavone/flavonols with 1, 2–dipalmitoyl–sn–glycero–3–phosphocholine (DPPC) bilayers. These are compared with standard flavone; chrysin (CHY) and flavonol Quercetin (QUE).Methods: The molecules studied are 4ʹ–methoxy flavone (MF), 3ʹ,4ʹ–dimethoxyflavone (DMF), 4ʹ–methoxyflavonol (MF–ol) and 3ʹ,4ʹ–dimethoxyflavonol (DMF–ol). The techniques used are Differential Scanning Calorimetry (DSC) and multi–nuclear NMR.Results: Highest binding to lipid bilayers is shown by DMF, followed by QUE. Based on DSC studies it is seen, that maximum interaction of MF and DMF, takes place with the hydrophobic core of lipid bilayers. DMF–ol shows formation of a heterogeneous system at higher concentrations. The 1H NMR spectra of unilamellar vesicles of DPPC, incorporated with MF, DMF and MF–ol shows significant interaction of these compounds with the alkyl chain of the hydrophobic core. MF, DMF and MF–ol acquire parallel orientation in bilayers with the B–ring pointing towards hydrophobic core, while DMF–ol acquire mixed orientation. This may be ascribed to the presence of two methoxy and one hydroxyl group on the B–ring of DMF–ol which hinders its partitioning inside the hydrophobic core of lipid bilayer. Multi–lamellar vesicles (MLV) of DPPC incorporated with flavones, show maximum increase in Chemical Shift Anisotropy in 31P spectrum of DMF. This is followed by MF. DSC.Conclusion: NMR and binding studies indicate that DMF is partitioned deeply inside the hydrophobic core, while MF, MF–ol and DMF–ol are mostly located in the vicinity of sn–glycero region. Therefore, we conclude that DMF which penetrates deepest inside the hydrophobic core also shows the highest anti–proliferative activity against K562 and MCF–7 cancer cell lines. Its activity is also better than CHY.

Aqueous injection of quercetin: An approach for confirmation of its direct in vivo cardiovascular effects

Potential positive effects of flavonol quercetin on humans were suggested by many studies. However, it is not clear if these effects are mediated by quercetin or its metabolites. The in vivo confirmation of quercetin effects is largely hindered by its low water solubility and thus impossibility to test directly its impact. Therefore, a solid dispersion of quercetin with polyvinylpyrrolidone (PVP) was developed to prepare an injectable formulation of water-soluble quercetin. The optimized formulation provided a 20,000-fold increase in quercetin solubility. This formulation was tested on conventional and spontaneously hypertensive rats; it lowered their blood pressure in both short- and long-term basis. Pharmacokinetic data are also provided. This study reports for the first time an injectable water-soluble formulation of quercetin suitable for confirmation of its vascular effect in vivo.

Comparison of spectrophotometric methods of total flavonoid assay based on complex formation with aluminum chloride as applied to multicomponent herbal drug angionorm

Objective: The objective was to compare the complex formation of flavones (luteolin, apigenin), flavonols (morin, quercetin, and rutin), flavanones (naringenin), flavanonols (dihydroquercetin), caffeic, and ferulic acids with aluminum ion using two spectrophotometric methods and the application of these methods to estimate the flavonoid content in the angionorm herbal product. Materials and Methods: Method 1 included direct complex formation with aluminum chloride, and Method 2 involved preliminary nitrozation and subsequent complex formation of nitroso-derivatives with aluminum chloride. 2,4-dinitrophenylhydrazine method was also tested. Results: The conjugation system increase in the chromophore structure of nitroso derivatives is reflected by the hyperchromic effect of all substances (from 1.4 to 4-fold). The largest bathochromic shift of nitroso derivatives was seen for rutin, luteolin, and dihydroquercetin (to 510–530 nm). The total flavonoids estimation in the extract of the four herbs mixture, which constitute angionorm preparation active ingredient, depends on the chosen reference substance (3.49% calculated as luteolin when measured by Method 1 or 8.71% by Method 2; 7.97% calculated as dihydroquercetin when measured by Method 1 and 4.14% by Method 2. Conclusion: The complex formation according to Methods 1 and 2 does not allow the identification of the selective spectral regions typical for the certain flavonoids subgroups and hydroxycinnamic acids. Neither method of complex formation is suitable for the assay of total flavonoids in unknown samples or for the flavonoid content comparison in the different herbal material.

Physicochemical stability of blood orange juice during frozen storage

ABSTRACTBlood orange juice from Citrus sinensis (L.) Osbeck cv. Moro was compared to a concentrated blood orange juice and both juices were studied during frozen storage at −20°C. Analyses were conducted on pH (3.33–3.81) and titratable acidity as citric acid (11.14–13.16 g/L). The formol number decreased in both blood orange juice and concentrated blood orange juice during frozen storage, while vitamin C showed a very slight decrease. Scavenging abilities of the juices for the DPPH∙ radical ranged from 53.39% to 42.55% in blood orange juice and from 39.16% to 33.75% in concentrated blood orange juice during frozen storage. Although anthocyanins showed a diminution during storage in both the concentrated and non-concentrated blood orange juice, they were always higher in the non-concentrated juice fruit. Four phenolic acids were detected: gallic, chlorogenic (the highest quantity, 13–27 mg/L), caffeic, and ferulic, the latter showed the lowest content. Ten flavonoids were identified, two flavonols (rutin and quercetin) and eight flavanones: narirutin (the second highest flavonoid), naringin, hesperidin (the highest quantity), neoeriocitrin, didymin, eriocitrin, neohesperidin, and hesperetin. Concentration and duration of frozen storage were found to influence the physicochemical properties of blood orange juice in different ways.

Phenolic compound profiles and their seasonal variations in new red-phenotype head-forming Chinese cabbages

In previous study, red Chinese cabbages which satisfy the morphological characteristics of traditional Chinese cabbages were developed by crossing Chinese cabbage and red cabbage, with subsequent backcrossing. In this study, we evaluated the phenolic compound profiles of two newly developed red-phenotype Chinese cabbages in comparison with three typical cultivars. Anthocyanidins (cyanidin), phenolic acids (caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid), and flavonols (quercetin and kaempferol) were identified and quantified by HPLC, LC/MS and LC/MS/MS analyses. The new cultivars contained significantly increased levels of phenolic compounds, except for kaempferol. Their contents drastically varied by sowing season. The spring-sown red Chinese cabbages contained significantly higher levels of phenolic acids (11,530 and 12,437 μg/g dry wt.) and cyanidin (1830 μg/g dry wt.) but lower levels of flavonols than their fall-sown counterparts. Correlation analysis exhibited a significant positive correlation between cyanidin and phenolic acids but a negative correlation between phenolic acids and flavonols in red Chinese cabbages. Principal component analysis could differentiate red Chinese cabbages and typical cultivars with different sowing seasons based on their phenolic compound profiles. This study provides information regarding the selection of appropriate Chinese cabbage cultivars rich in phenolic compounds that may benefit human health.

Quantification of rutin and quercetin by HPTLC/HPLC and in vitro immunomodulatory and anticancer activities of Capparis moonii fruits extracts

Background: The current research was undertaken on dried fruits of Capparis moonii to screen its potential for immunomodulatory and cancer indications with identification of phytoconstituents by chromatographic techniques.Methods: Methanolic (MECN), hydro-methanolic (HMECN) and aqueous extracts (AQCN) of Capparis moonii were subjected to high performance thin layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC) after studying the total phenolic and flavonoid content by using rutin and gallic acid as standards respectively as well as undertaking powder characteristics and preliminary phytochemical screening. Immunomodulatory activities covered were hemagglutination antibody titre and delayed-type hypersensitivity reaction with the aid of sheep red blood cells (0.5×109) as antigens. The extracts were studied for antioxidant potential. Anticancer prospects were focusing on in vitro cell lines screening (MCF 7 and HCT 15) by Sulforhodamine B assay method and potato disc assay.Results: The total phenolic and flavonoid content of MECM, HMECM and AQCM fruits extracts were found to be 0.20, 0.11 and 0.47 mg of gallic acid/g and 78.3, 18.8 and 64.4 mg of rutin/g respectively. Rutin and quercetin were confirmed by HPTLC and HPLC showing well resolved peaks. IC50 values in antioxidant studies were found to be significant with all the extracts. Significant immunomodulatory effect was noticed at 200mg/kg in both models (high antibody titre levels and decrease paw volume after 48 h). Unsatisfactory results were observed with selected cell lines and disc assay.Conclusions: Thus, selected fruits may probably have immunomodulatory potential due to presence of flavonols (rutin and quercetin).

Infrared spectroscopy of flavones and flavonols. Reexamination of the hydroxyl and carbonyl vibrations in relation to the interactions of flavonoids with membrane lipids

Detailed vibrational assignments for twelve flavonoids (seven flavones (flavone, 3- and 5-hydroxyflavone, chrysin, apigenin, fisetin and luteolin) and five flavonols (galangin, kaempferol, quercetin, morin and myricetin)) have been made based on own and reported experimental data and calculations at the B3LYP/6-31+G(d,p) level of theory. All the molecules are treated in a uniform way by using the same set of redundancy-free set of internal coordinates. A generalized harmonic mode mixing is used to corroborate the vibrational characteristics of this important class of molecules. Each flavonoid molecule can be treated from the vibrational point of view as made of relatively weakly coupled chromone and phenyl part. It has been shown that the strongest band around 1600cm−1 need not be attributable to the CO stretching. The way the vibrations of any of the hydroxyl groups are mixed with ring vibrations and vibrations of other neighboring hydroxyl groups is rather involved. This imposes severe limitations on any attempt to describe normal modes of a flavonol in terms of hydroxyl or carbonyl group vibrations. The role of water molecules in the appearance of flavonoid IR spectra is emphasized. Knowing for the great affinity of phosphate groups in lipids towards water, the immediate consequence is a reasonable assumption that flavonoid lipid interactions is mediated by water.

LC-MS/MS Analysis of Flavonoid Compounds from Zanthoxylum zanthoxyloides Extracts and Their Antioxidant Activities

Flavonoids are a large group of phenolic secondary metabolites having a wide range of biochemical and pharmacological effects. In this work, a targeted liquid chromatography (LC) coupled with tandem mass spectrometry (MS2) was used to characterize the flavonoid compositions of methanolic plant extracts from separated parts (fruits, leaves, stems, trunk barks, and root barks) of Zanthoxylum zanthoxyloides. Nine flavonoids were reported in this species, including three flavanones, five flavonols and one flavone. Quantitative analysis of flavonoid profiles from Z. zanthoxyloides extracts is useful to a better understanding of the pattern and distribution of metabolites in extract samples. The concentrations of two glycosylated flavanones (neohesperidin and hesperidin) and one flavonol (quercetin) were higher in root and trunk samples compared to fruit samples. These compounds were reported in small amounts in the stem and leaf samples. In contrast, four flavonols (hyperoside, quercetin-3- O-glucopyranoside, datiscin and quercitrin) were present in significant levels only in the leaf extracts. The presence of glycosylated flavanone (eriocitrin) has been reported only in fruit extract. The antioxidant properties of different extracts were tested regarding their scavenging activities on ABTS•+ radical. Leaf and trunk bark extracts exhibited antioxidant activities, while the extracts obtained from other organs (fruits, stems, and root barks) showed low antioxidant properties.

Anti-degenerative effect of Apigenin, Luteolin and Quercetin on human keratinocyte and chondrocyte cultures: SAR evaluation.

Inflammation is a dynamic process that occur on vascularized tissue in response to different stimuli causing cell injury and tissue degeneration. Reactive oxygen and nitrogen species (ROS and RNS) and advanced glycation end products (AGEs) have a key mediatory role in the development and progression of degenerative tissue process. The bioflavonoids possess a broad-spectrum of pharmacological activities. Their capability is related to their chemical structure. In this study we evaluated and compare antioxidant, anti-glycative and anti-degenerative actions of two flavones apigenin and luteolin and a flavonol quercetin, in function of their hydroxyl groups arrangement. Moreover we assay, on NCTC 2544 and chondrocytes cultures, the flavonoids capacity to modulate NO and glycosamminoglycans levels, index of antidegenerative capacity. All tested flavonoids act as free radicals scavengers (ROO• and NO•) and advanced glycation end products inhibitors, in agreement with their BDE, IP and molecular planarity. Quercetin showed a high ORAC value (2.70±0.12 ORAC Units), according to a low BDE (74.54 Kcal/mol) and IP (174.44 Kcal/mol) values. Luteolin is the most active compound in the NO (48.19±0.18%) and AGEs (60.06±0.52%) inhibition, in function of a low torsion angle (16.3°) between the 3-OH moiety and C'6 carbon atom. All tested flavonoids posses a protective role on degenerative tissue events. They acts in different manner depending on the functional groups, the biological substrate and the concentration used. In any case, it can be considered a suitable product preventing a degenerative processes.

Validation of Spectrophotometric Methods for the Determination of Total Polyphenol and Total Flavonoid Content.

The aim of this study was to validate spectrophotometric methods for the measurement of total polyphenol (TP; via the Folin-Ciocalteu method) and total flavonoid (TF) content [via the aluminum chloride (AlCl3) method]. Validation parameters of these methods were determined, including linearity, sensitivity, precision (intra-assay and intermediate), accuracy, LOD, and LOQ. For the validation process, groups of polyphenol standards were used, including phenolic acids (gallic, p-coumaric, caffeic, and chlorogenic acids), flavan-3-ols [(+)-catechin and procyanidins B1 and B2], flavonols (quercetin and quercetin-3-rutinoside), and dihydrochalcones (phloretin and phloretin-2-glucoside). Obtained validation parameters were within acceptable ranges with high determination coefficients, reasonably low LODs and LOQs, and high slopes in the calibration curves for both methods, except for phloretin and phloretin-2-glucoside, for which there were low slopes in the calibration curves for the AlCl3 method. To evaluate differences in polyphenol content, the validated spectrophotometric methods were used to determine TP and TF content in wines (Plavac, Graševina, and Vranac) and juices (blueberry, strawberry, and blackcurrant juice) according to the polyphenol calibration curves. Polyphenol contents were different for both methods in all wines and juices.

Structural Elucidation of a New Flavolignan Acylglycoside from Fallen Needles of Pinus banksiana

A new flavolignan acylglycoside, namely phillygenin 4-O-(2′′-trans-cinnamoyl)-α-L-rhamnopyranoside (1), along with a known phenolic acid (ellagic acid, 2) and three known flavonol glycosides (kaempferol 3-O-β-D-glucopyranoside (3), kaempferol 3-O-α-L-rhamnopyranoside (4), and quercetin 3-O-β-D-glucopyranoside (5), was isolated and purified from the fallen needles of Pinus banksiana by repeated column chromatography. The structures of these secondary metabolites were mainly elucidated by the extensive use of 1D and 2D NMR experiments, together with IR, UV, and FAB MS spectra. Among the four known compounds, 2 and 4 have never been found in this conifer species previously.

Impact of grape dehydration process on the phenolic composition of wines during bottle ageing

The effect of grapes dehydration on, phenolic profile was evaluated in wines during bottle ageing. Wines produced with Cabernet Sauvignon and Merlot grapes, dehydrated in different percentages (30 and 40%) under controlled conditions, were analyzed by spectrophotometric and chromatographic assays during 22 months of storage. The phenolic profile of the wines and their evolution during bottle ageing was different according to the grape variety and the percentage of dehydration applied. An increase in the concentration of phenolic acids (gallic, protocateic, coumaric) and flavonols (quercetin, campferol, and myricetin) was observed in all samples during bottle ageing, along with a reduction of anthocyanin (delphinidin, malvidin, peonidine, and cyanidin 3-O-glucoside) and flavanols (+)-catechin and (−)-epicatechin). Main changes in the phenolic composition of all wines occurred during the 10th and 13th month, but the changes in wines produced from dried grapes were softer than control wines, indicating that dehydration process improve the wine phenolic stability and permit long periods of ageing for this kind of wines. Practical applications Different wine regions utilize the grape dehydration to produce differentiated and high value-added wines. This study provides an overview on the effect of grape dehydration process under controlled conditions on wine phenolic evolution during bottle ageing. The results provide relevant information about the storage time required for this kind of wine to improve its commercialization and consumption.

The role of polyphenols in modern nutrition.

Polyphenols are found in plant‐based foods and beverages, notably apples, berries, citrus fruit, plums, broccoli, cocoa, tea and coffee and many others. There is substantial epidemiological evidence that a diet high in polyphenol‐rich fruit, vegetables, cocoa and beverages protects against developing cardiovascular disease and type 2 diabetes. The absorption and metabolism of these compounds have been well described and, for many, the gut microbiota play a critical role in absorption; taking into consideration the parent compound and the metabolites from colon bacteria catabolism, more than 80% of a dose can be absorbed and ultimately excreted in the urine. Common polyphenols in the diet are flavanols (cocoa, tea, apples, broad beans), flavanones (hesperidin in citrus fruit), hydroxycinnamates (coffee, many fruits), flavonols (quercetin in onions, apples and tea) and anthocyanins (berries). Many intervention studies, mechanistic in vitro data and epidemiological studies support a role for polyphenols against the development of chronic diseases. For example, flavanols decrease endothelial dysfunction, lower blood pressure and cholesterol, and modulate energy metabolism. Coffee and tea both reduce the risk of developing type 2 diabetes, through action of their constituent polyphenols. Despite extensive research, the exact mechanisms of action of polyphenols in the human body have not been decisively proven, but there is strong evidence that some targets such as nitric oxide metabolism, carbohydrate digestion and oxidative enzymes are important for health benefits. Consumption of polyphenols as healthy dietary components is consistent with the advice to eat five or more portions of fruit and vegetables per day, but it is currently difficult to recommend what ‘doses’ of specific polyphenols should be consumed to derive maximum benefit.

Flavonoid profile, antioxidant and antiglycation properties of Retama sphaerocarpa fruits extracts

Retama sphaerocarpa occurs in the Mediterranean area of North-east Africa and in the Iberian Peninsula, and grows on a variety of soil types and climatic conditions. Used in Algerian folk medicine, it is a valuable species for revegetation and soil restoration. The aim of this study is to evaluate flavonoid composition and antioxidant and antiglycation properties of methanolic and aqueous extracts from R. sphaerocarpa fruits. HPLC-PDA/ESI-MS was used to identify/quantify flavonoid content. Antioxidant activity was evaluated by Folin–Ciocalteu, ORAC, FRAP, TEAC, and DPPH assays, and antiglycation capability by glucose/fructose-BSA assay. Results showed that fruits contain isoflavones (daidzein and genistein derivatives) and flavonols (apigenin, isorhamnetin, kaempferol and quercetin derivatives), and extracts (especially the methanolic one, richer in flavonoids) possess good in vitro antioxidant and antiglycation properties. These findings evidence that R. sphaerocarpa fruits are a source of valuable phytochemicals, with potential applications in the field of phytopharmaceuticals and in food industry.

Chemical Profiling and Assessment of Antineurodegenerative and Antioxidant Properties of Veronica teucrium L. and Veronica jacquinii Baumg.

Neuroprotective potential of V. teucrium and V. jacquinii methanol extracts was analyzed. Chemical analysis of investigated extracts showed the presence of phenolic acid derivatives, flavonoids and one secoiridoid. The detected flavonoids derived from flavones (luteolin and isoscutellarein in V. jacquinii; apigenin, isoscutellarein and luteolin in V. teucrium) and flavonol (quercetin in V. jacquinii). Acteoside was the dominant compound in V. jacquinii, while plantamajoside and isoscutellarein 7-O-(6‴-O-acetyl)-β-allosyl (1‴→2‴)-β-glucoside were the major phenolics in V. teucrium. Additionally, the antineurodegenerative activity was tested at concentrations of 25, 50, and 100 μg/ml using acetylcholinesterase (AChE) and tyrosinase (TYR) assays. The inhibition of both enzymes was achieved with the investigated extracts, ranging from 22.78 to 35.40% for AChE and from 9.57 to 16.38% for TYR. There was no statistical difference between the activities of the analyzed extracts. Our data indicate that V. teucrium and V. jacquinii may have beneficial effects against Alzheimer's and Parkinson's disease.

Abstract 2117: TRAIL-induced apoptosis in TRAIL-resistant breast carcinoma

Abstract Recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL), the optimized form of the endogenous death ligand TRAIL, shows therapeutic potential for cancer due to its ability to induce apoptosis in cancer cells independent of p53, while exhibiting minimal toxicity to normal cells. Despite this, a majority of breast cancers display resistance to rhTRAIL treatment due to up-regulation of pro-apoptotic proteins, down-regulation of anti-apoptotic proteins, and/or up-regulation of death receptors (DR) 4 and 5. To overcome rhTRAIL resistance, natural compounds have been investigated as sensitizing agents. This study considered the application of the naturally occurring flavonol Quercetin (Q). Q has been shown to have the ability to up-regulate DR5 and down-regulate anti-apoptotic proteins in cancer cells, and thereby, making Q a favorable choice to be employed as a sensitizing agent. The intention of this study was to ascertain the capacity of Q to sensitize rhTRAIL-resistant triple negative breast cancer BT-20 cells and hormone-dependent breast cancer MCF-7 cells to rhTRAIL-induced apoptosis and elucidate the underlying mechanism for Q’s sensitization. Q demonstrated the ability to intensify rhTRAIL’s pro-apoptotic effects in the breast cancer BT-20 and MCF-7 cell lines as detected through Annexin V/PI assays followed by FACS analysis. In comparison to single agent treatments, the cotreatment of Q and rhTRAIL enhanced the induction of the extrinsic pathway of apoptosis as marked by PARP cleavage (a hallmark of apoptosis), activation of caspase 8, and activation of the executioner caspases 3 and 7. The mechanism for Q’s augmentation in breast cancer was determined to be through the down-regulation of c-FLIPL (caspase 8 inhibitor) in a dose-dependent manner. Furthermore, Q promoted the ubiquitination of c-FLIPL facilitating the proteasome-mediated degradation of c-FLIPL in breast cancer. An additional mechanism for Q’s sensitization was displayed in breast cancer BT-20 cells. Q up-regulated DR5 membrane and protein expression in breast cancer BT-20 cells in a dose-dependent manner. RT-PCR analysis revealed that Q’s influence on DR5 expression occurred at the transcriptional level in those breast cancer cells. Thus, these data suggest that the cotreatment of Q and rhTRAIL possesses the therapeutic potential to be an effective anti-breast carcinoma regimen. Citation Format: Jasmine M. Manouchehri, Michael Kalafatis. TRAIL-induced apoptosis in TRAIL-resistant breast carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2117. doi:10.1158/1538-7445.AM2017-2117

Genome-Wide Identification and Functional Characterization of UDP-Glucosyltransferase Genes Involved in Flavonoid Biosynthesis in Glycine max.

Flavonoids, natural products abundant in the model legume Glycine max, confer benefits to plants and to animal health. Flavonoids are present in soybean mainly as glycoconjugates. However, the mechanisms of biosynthesis of flavonoid glycosides are largely unknown in G. max. In the present study, 212 putative UDP-glycosyltransferase (UGT) genes were identified in G. max by genome-wide searching. The GmUGT genes were distributed differentially among the 20 chromosomes, and they were expressed in various tissues with distinct expression profiles. We further analyzed the enzymatic activities of 11 GmUGTs that are potentially involved in flavonoid glycosylation, and found that six of them (UGT72X4, UGT72Z3, UGT73C20, UGT88A13, UGT88E19 and UGT92G4) exhibited activity toward flavonol, isoflavone, flavone and flavanol aglycones with different kinetic properties. Among them, UGT72X4, UGT72Z3 and UGT92G4 are flavonol-specific UGTs, and UGT73C20 and UGT88E19 exhibited activity toward both flavonol and isoflavone aglycones. In particular, UGT88A13 exhibited activity toward epicatechin, but not for the flavonol aglycones kaempferol and quercetin. Overexpression of these six GmUGT genes significantly increased the contents of isoflavone and flavonol glucosides in soybean hairy roots. In addition, overexpression of these six GmUGT genes also affected flavonol glycoside contents differently in seedlings and seeds of transgenic Arabidopsis thaliana. We provide valuable information on the identification of all UGT genes in soybean, and candidate GmUGT genes for potential metabolic engineering of flavonoid compounds in both Escherichia coli and plants.