naringenin-chalcone and naringenin

Naringenin (Nar) and its structural isomer, naringenin chalcone (ChNar), are two natural phytophenols with beneficial health effects belonging to the flavonoids family. A direct discrimination and structural characterization of the protonated forms of Nar and ChNar, delivered into the gas phase by electrospray ionization (ESI), was performed by mass spectrometry-based methods. In this study, we exploit a combination of electrospray ionization coupled to (high-resolution) mass spectrometry (HR-MS), collision-induced dissociation (CID) measurements, IR multiple-photon dissociation (IRMPD) action spectroscopy, density functional theory (DFT) calculations, and ion mobility-mass spectrometry (IMS). While IMS and variable collision-energy CID experiments hardly differentiate the two isomers, IRMPD spectroscopy appears to be an efficient method to distinguish naringenin from its related chalcone. In particular, the spectral range between 1400 and 1700 cm

Topics: Chalcones; Ion Mobility Spectrometry; Spectrophotometry, Infrared

Chalcone isomerase-like (CHIL) protein is a noncatalytic protein that enhances flavonoid content in green plants by serving as a metabolite binder and a rectifier of chalcone synthase (CHS). Rectification of CHS catalysis occurs through direct protein-protein interactions between CHIL and CHS, which alter CHS kinetics and product profiles, favoring naringenin chalcone (NC) production. These discoveries raise questions about how CHIL proteins interact structurally with metabolites and how CHIL-ligand interactions affect interactions with CHS. Using differential scanning fluorimetry on a CHIL protein from Vitis vinifera (VvCHIL), we report that positive thermostability effects are induced by the binding of NC, and negative thermostability effects are induced by the binding of naringenin. NC further causes positive changes to CHIL-CHS binding, whereas naringenin causes negative changes to VvCHIL-CHS binding. These results suggest that CHILs may act as sensors for ligand-mediated pathway feedback by influencing CHS function. The protein X-ray crystal structure of VvCHIL compared with the protein X-ray crystal structure of a CHIL from Physcomitrella patens reveals key amino acid differences at a ligand-binding site of VvCHIL that can be substituted to nullify the destabilizing effect caused by naringenin. Together, these results support a role for CHIL proteins as metabolite sensors that modulate the committed step of the flavonoid pathway.

Topics: Binding Sites; Bryopsida; Crystallography, X-Ray; Enzyme Stability; Flavonoids; Fluorometry; Intramolecular Lyases; Ligands; Plant Proteins; Vitis

Combinatorial biosynthesis has great potential for designing synthetic circuits and amplifying the production of new active compounds. Studies on multienzyme cascades are extremely useful for improving our knowledge on enzymatic catalysis. In particular, the elucidation of enzyme substrate promiscuity can be potentially used for bioretrosynthetic approaches, leading to the design of alternative and more convenient routes to produce relevant molecules. In this perspective, plant-derived polyketides are extremely adaptable to those synthetic biological applications. Here, we present a combination of an

Topics: Acyltransferases; Arabidopsis; Arabidopsis Proteins; Chalcones; Escherichia coli; Flavanones; Genetic Vectors; Malonyl Coenzyme A; Plasmids; Polyketide Synthases; Polyketides; Substrate Specificity; Synthetic Biology

Flavonoids, found in almost all fruits and vegetables, belong to a class of plant secondary metabolites with a polyphenolic structure and have properties with health-improving potential. However, few experimental studies on the effects of flavonoids have been carried out in vivo after external application and using pure compounds. Aiming to fill this gap, in this study we tested the topical anti-inflammatory and antiallergic activity of three flavonoids of high purity, naringenin, naringenin chalcone, and quercetin, in mouse models. The topical anti-inflammatory effects were assessed against arachidonic acid- (AA) and tetradecanoylphorbol-13-acetate- (TPA) induced ear edema. The anti-inflammatory effect of naringenin against ear edema was noticeable at a 1% dose in the AA model and at half this dose in the TPA model. Quercetin (1.3%) did not exert any topical anti-inflammatory activity in the AA model, but its inhibitory effect in the TPA model was similar to that of naringenin (2%); in contrast, naringenin chalcone was more active against the AA-induced than TPA-induced inflammation. The flavonoid effect on IgE-mediated passive cutaneous anaphylaxis was also studied in mice, both intravenously and topically. Naringenin, naringenin chalcone, and quercetin all showed strong antiallergic activity after intravenous dosing (0.02%) and when applied topically (2%). The results of this study suggest that the flavonoids naringenin, naringenin chalcone, and quercetin may be useful alternatives for the topical treatment of inflammatory and allergic skin disorders.

Topics: Animals; Anti-Allergic Agents; Anti-Inflammatory Agents; Chalcones; Female; Flavanones; Immunoglobulin E; Mice; Passive Cutaneous Anaphylaxis; Quercetin

The effect of industrial and home processing, in vitro gastrointestinal digestion, individual phenolic content, and antioxidant capacity of tomato into tomato sauce were investigated. Industrial processing of tomato fruit into sauce had an overall positive effect on the total antioxidant capacity (∼1.2-fold higher) compared to tomato fruit whereas home processing of tomato fruit into sauce led to a decrease in these values. Untargeted LC-QTOF-MS analysis revealed 31 compounds in tomato that changed upon processing, of which 18 could be putatively identified. Naringenin chalcone is only detectable in the fruit, while naringenin is strongly increased in the sauces. Rutin content increased by 36% in the industrial processed sauce whereas decreased by 26% in the home processed sauce when compared to fruit. According to the results of an in vitro gastrointestinal digestion model, industrial processing may lead to enhanced bioaccessibility of antioxidants.

Topics: Antioxidants; Chalcones; Chromatography, Liquid; Flavanones; Flavonoids; Food Handling; Phenols; Rutin; Solanum lycopersicum

Inhibition of α-glucosidase and α-amylase decreases postprandial blood glucose levels and delays glucose absorption, making it a treatment strategy for type 2 diabetes. This study examined in vivo and in vitro antidiabetic activities of natural prenylchalconaringenins 1 and 2 and prenylnaringenins 3 and 4, found in hops and beer. 3'-Geranylchalconaringenin (2) competitively and irreversibly inhibited α-glucosidase (IC

Topics: alpha-Amylases; alpha-Glucosidases; Animals; Blood Glucose; Chalcones; Diabetes Mellitus, Type 2; Flavanones; Glycoside Hydrolase Inhibitors; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Mice; Plant Extracts

A chalcone synthase gene ( PaCHS ) was isolated and functionally characterized from liverwort. The ectopic expression of PaCHS in Marchantia paleacea callus raised the flavonoids content. Chalcone synthase (CHS; EC 2.3.1.74) is pivotal for the biosynthesis of flavonoid and anthocyanin pigments in plants. It produces naringenin chalcone by condensing one p-coumaroyl- and three malonyl-coenzyme A thioesters through a polyketide intermediate that is cyclized by intramolecular Claisen condensation. Although CHSs of higher plants have been extensively studied, enzyme properties of the CHSs in liverworts have been scarcely characterized. In this study, we report the cloning and characterization of CHS (designated as PaCHS) from the liverwort Plagiochasma appendiculatum. The gene product was 60-70 % identical with chalcone synthases from other species, and contained the characteristic conserved Cys-His-Asn catalytic triad. The recombinant PaCHS was able to catalyze p-coumaroyl-CoA and malonyl-CoA to generate naringenin in vitro. Heterologously expressed PaCHS protein showed similar kinetic properties to those of higher plant CHS. The ectopic expression of PaCHS in Marchantia paleacea callus raised the content of the total flavonoids. These results suggested that PaCHS played a key role in the flavonoids biosynthesis in liverworts. Furthermore, when the thallus of P. appendiculatum was treated with abiotic stress inducers methyl jasmonate, salicylic acid and abscisic acid, PaCHS expression was enhanced. This is the first time that a CHS in liverworts has been functionally characterized.

Topics: Abscisic Acid; Acetates; Acyltransferases; Amino Acid Sequence; Anthocyanins; Biosynthetic Pathways; Chalcones; Cyclopentanes; Flavanones; Flavonoids; Gene Expression; Hepatophyta; Marchantia; Models, Molecular; Molecular Sequence Data; Oxylipins; Phylogeny; Plant Growth Regulators; Recombinant Proteins; Salicylic Acid; Sequence Alignment; Sequence Analysis, DNA; Transgenes

In order to investigate the effect of home processing on the bioaccessibility of health-related constituents of tomatoes, total lycopene, phenolics, flavonoids and antioxidant capacity were determined from seven different tomato products using an in vitro gastrointestinal digestion model. Additionally, the changes in the contents of the major tomato phenolics were determined and compared for these different tomato products using HPLC.. The results revealed that paste processing and drying significantly increased the bioaccessible total lycopene content (2.2- and 3.8-fold, respectively), total phenolic content (2.3- and 2.0-fold, respectively), total flavonoid content (9.0- and 2.5-fold, respectively) and total antioxidant capacity (6.3- and 8.0-fold for the DPPH assay, 26- and 33-fold for the CUPRAC assay, respectively) (P < 0.05) compared to fresh tomatoes. HPLC analysis revealed significantly lower (P < 0.05) rutin content in puree and juice. The loss of naringenin chalcone in some tomato products, as well as its conversion into naringenin in heat-treated products was observed.. The current study provided valuable insights into the changes in the content and bioaccessibility of tomato antioxidants as a result of home processing.

Topics: Antioxidants; Biological Availability; Biphenyl Compounds; Carotenoids; Chalcones; Chromatography, High Pressure Liquid; Desiccation; Diet; Flavanones; Flavonoids; Food Handling; Fruit; Humans; In Vitro Techniques; Lycopene; Phenols; Picrates; Rutin; Solanum lycopersicum

Fresh cherry tomatoes cv. 'Susanne' contain more of the two flavonoids chalconaringenin (CN) and rutin than lycopene. Therefore some properties including antioxidant behavior of the flavonoids were studied. The two flavonoids were extracted from peel and isolated by use of different chromatographic methods. Molecular absorbtivities were found to be 26907 for CN and 20328 abs M(-1) cm(-1) for rutin. Both compounds exhibited properties as antioxidants through several assays, and rutin was found to be the strongest antioxidant except in one assay. None of the assays revealed pro-oxidative effects. As naringenin rather than CN is frequently reported as a tomato constituent, the stability of CN was investigated in order to detect potential ways of isomerization during sample preparation. CN isomerized slowly both under UVB radiation and in alkaline solutions. Thus, such factors do not explain the occurrence of naringenin in tomato samples. The deficiency in reports on CN may be explained by the similarity in chromatographic behaviors of CN and naringenin, and due to the fact that they have same molecular weights.

Topics: Antioxidants; Chalcones; Drug Stability; Flavanones; Fruit; Isomerism; Rutin; Solanum lycopersicum

The human fecal anaerobe Eubacterium ramulus is capable of degrading various flavonoids, including the flavone naringenin. The first step in the proposed degradation pathway is the isomerization of naringenin to the corresponding chalcone. Cell-free extracts of E. ramulus displayed chalcone isomerase activity. The enzyme from E. ramulus was purified to homogeneity. Its apparent molecular mass was estimated to be 136 and 129 kDa according to gel filtration and native polyacrylamide gel electrophoresis, respectively. Chalcone isomerase is composed of one type of subunit of 30 kDa. The purified enzyme catalyzed the isomerization of naringenin chalcone, isoliquiritigenin, and butein, three chalcones that differ in their hydroxylation pattern. N-bromosuccinimide, but also naringenin and phloretin, inhibited the purified enzyme considerably. This is the first report on a bacterial chalcone isomerase. The physiological function of the purified enzyme is unclear, but an involvement in the conversion of the flavanone naringenin to the chalcone is proposed.

Topics: Bromosuccinimide; Chalcone; Chalcones; Chromatography, Gel; Electrophoresis, Polyacrylamide Gel; Enzyme Inhibitors; Eubacterium; Flavanones; Flavonoids; Intramolecular Lyases; Isomerism; Molecular Weight; Phloretin; Protein Subunits; Substrate Specificity

Water permeability of isolated cuticular membranes from mature green and ripe Lycopersicon esculentum Mill, fruits was investigated. The water permeability of ripe tomato cuticles in the H+ form was strongly dependent on pH and increased when the pH of the external solution increased. The water permeability of the cuticles of mature green fruits was higher than that of the ripe fruit cuticles and had a low pH dependence. The isolated fruit cuticles were put in the Na+ form at three different pH levels and their water permeabilities were measured at the respective pH values in the external solution. The water permeability values were related to the nature and exchange capacity of hydroxyl functional groups of the flavonoids naringenin and chalconaringenin present in the ripe tomato cuticles, and to the phenolic acids of both types of cuticles. Whereas the water permeability of the mature green cuticles in the sodium form increased according to their small exchange capacity, the water permeability of ripe tomato cuticles reached a saturation value at high pH. The results indicate that the flavonoids play an important role in the control of water transport across the polymer matrix of these membranes. X-ray diffraction study of the different cuticles confirmed structural changes in the polymer when the isolated cuticles were put in the different homoionic forms. Analysis of the basal spacings confirms a structural model of tomato fruit cuticle with two major hydrophobic interplanar spaces around 1.0 and 0.45 nm wide.

Topics: Cell Membrane; Cell Membrane Permeability; Chalcone; Chalcones; Flavanones; Flavonoids; Hydrogen-Ion Concentration; Hydroxybenzoates; Solanum lycopersicum; Spectroscopy, Fourier Transform Infrared; Water; X-Ray Diffraction