DOCSLIB.ORG

ABSTRACT TANNINS AS ANTI-INFLAMMATORY AGENTS By

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
ABSTRACT TANNINS AS ANTI-INFLAMMATORY AGENTS By ABSTRACT TANNINS AS ANTI-INFLAMMATORY AGENTS By Melanie Diane Jeffers The potential of dietary and herbal polyphenols to act as beneficial antioxidants or anti-inflammatory agents, or as harmful pro-oxidants, is a topic of intense current interest. The first half of this research involved using SDS-PAGE gels to elucidate tannin-protein complexation. The second half of this study attempts to evaluate the anti- inflammatory or pro-inflammatory activity of the tannin pentagalloyl glucose within an ex vivo model system using peripheral blood mononuclear cells from rabbit. The oxidative burst from cells stimulated with phorbol ester was monitored with cytochrome c. The results provide preliminary data that supports the hypothesis that tannins such as pentagalloyl glucose minimize the inflammatory response. TANNINS AS ANTI-INFLAMMTORY AGENTS A Thesis Submitted to the Faculty of Miami University in partial fulfillment of the requirements for the degree of Masters of Science Department of Chemistry and Biochemistry By Melanie Diane Jeffers Miami University Oxford, Ohio 2006 Advisor _______________________ Dr. Ann E. Hagerman Reader ________________________ Dr. John W. Hawes Reader _________________________ Dr. Gary A. Lorigan Reader _________________________ Dr. Kevin W. Kittredge Table of Contents Page List of Figures iv Abbreviations vi 1. Introduction: Tannins as Anti-Inflammatory Agents 1.1. Tannins 1 1.1.1. What is a tannin 1 1.1.2. Human exposure to tannins 2 1.1.3. Tannin-protein complexes 3 1.1.4. Anti-nutritional effects of dietary tannins 4 1.2. Tannins and Reactive Oxygen Species 4 1.2.1. Tannins and the inflammatory system 6 1.2.2. Inflammatory diseases 7 1.2.3. Inflammatory bowel diseases 8 1.3. Hypothesis 10 1.4. Chapter 1 References 12 2. Characterization of soluble protein-tannin complexes using Ribonuclease A and Pentagalloyl glucose (β-1,2,3,4,6-Pentagalloyl-O-D-Glucopyranose) 2.1. Introduction 18 2.2. Material and Methods 19 2.3. Results and Discussion 20 2.4. Chapter 2 References 41 3. Analytical methods for monitoring the inflammatory the response 3.1. Introduction 43 3.1.1. Superoxide as one of the first signaling molecules 43 3.1.2. Rationale for using cytochrome c 44 3.2. Methods 45 3.2.1. Reagents 45 3.2.2. Validation 45 3.3. Results and Discussion 45 3.4. Chapter 3 References 51 ii 4. Investigation of tannins as anti-inflammatory agents 4.1. Introduction 53 4.1.1. Peripheral blood mononuclear cells (PBMCs) 53 4.2. Methods 55 4.2.1. Reagents 55 4.2.2. Isolation of peripheral blood mononuclear cells (PBMC) 56 4.2.3. Incubation and priming of PBMCs 57 4.2.4. PMA stimulation of PBMCs 57 4.2.5. Superoxide production from PBMCs 57 4.2.6. PGG interference with cytochrome c 57 4.2.7. Lucigenin as a probe for superoxide 58 4.3. Results 58 4.4. Discussion 60 4.5. Chapter 4 References 70 iii List of Figures 1. Chapter 1. Figures Page 1.1. Structures of representative tannins. 11 2. Chapter 2. Figures 2.1. Optimal pH for PGG-RNase complex formation. 26 2.2. Optimal RNase:PGG ratio for complex formation. 27 2.3. Effect of excess PGG on complex formation. 28 2.4. SDS PAGE to detect PGG-RNase complexes. 29 2.5. Higher percent acrylamide SDS PAGE to better resolve PGG-RNase complexes. 30 2.6. Gradient SDS-PAGE to detect PGG-RNase complexes. 31 2.7. Effect of dialysis on PGG-RNase complexes. 32 2.8. Effect of β-ME on PGG-RNase complexes. 33 2.9. Order of addition of reagents. 34 2.10. Effect of urea on PGG-RNase complex formation. 35 2.11. Proteolysis with trypsin. 36 2.12. Proteolysis with subtilisin and trypsin. 37 2.13. Proteolysis and Tris/Tricine gels. 38 2.14. Proteolysis with 14C radiolabelled PGG using subtilisin. 39 2.15. Periodate reaction with RNase. 40 3. Chapter 3. Figures 3.1. Cytochrome c spectrum. 48 3.2. Cytochrome c reduction by stimulated monocyte cells. 49 3.3. Relationship between reduced cytochrome c and slope of the spectral peak. 50 4. Chapter 4. Figures 4.1. Superoxide production from rabbit PBMCs in the presence of cytochrome c. 63 4.2. Superoxide production represented as slope of the spectral data. 64 4.3. Superoxide production from cells exposed to tannin. 65 iv 4.4. PGG reduces cytochrome c. 66 4.5. Superoxide production in PGG-treated cells. 67 4.6. Superoxide production from rabbit PBMCs probed with lucigenin. 68 4.7. Superoxide production from cells exposed to tannin using lucigenin as a probe. 69 v Abbreviations 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) bovine serum albumin (BSA) cyclooxygenase (COX-2) dimethyl sulfoxide (DMSO) ethylenediamine-tetraacetic acid (EDTA) epigallocatechin gallate (EGCG) gastrointestinal (GI) Hank’s balanced salt solution (HBSS) helper T-cells (Th) hydrogen peroxide (H2O2) hydroxyl radical (OH•) hypochlorous acid (HOCl) inducible nitric oxide synthase (iNOS) inflammatory bowel disease (IBD) interferons (IFN) interleukins (IL) lipopolysaccharide (LPS) β-mercaptoethanol (β-ME) nitric oxide radical (NO•) nitroblue tetrazolium (NBT) β-1,2,3,4,6-pentagalloyl-O-D-glucopyranose (PGG) peripheral blood mononuclear cells (PBMC) phorbol 12-mysristate 13-actetate (PMA) potassium superoxide (KO2) procyanidin (PC) prostaglandin E2 (PGE2) reactive oxygen species (ROS) ribonuclease A (RNase) sodium dithionite (Na2S2O4) vi sodium dodecyl sulfate (SDS) sodium periodate (NaIO4) •- superoxide anion (O2 ) superoxide dismutase (SOD) tumor necrosis factors (TNF) vii 1. Introduction: Tannins as Anti-Inflammatory Agents 1.1. Tannins 1.1.1. What is a tannin? Tannins are a complex family of naturally occurring polyphenols that most characteristically precipitate gelatin and other proteins (1). Other phenolic compounds also have the ability to bind with protein, but do not form the insoluble, cross-linked complexes typically formed by tannin-protein mixtures (2). Tannins were originally used in the process of tanning or conversion of animal hides into leather by precipitating the proteins, such as collagen, found in the skin of the animal (3). Their name is derived from the Celtic word for oak, a traditional source for tannin-containing extracts for preparing leather (4). Tannins are secondary metabolites produced by plants presumably to provide protection from disease and mammalian herbivores. These polymeric polyphenols, which have molecular weights ranging from 0.5 to 22 kD, have unique chemical and biological activities (5). In addition to binding protein, tannins are also potent metal ion chelators, tightly binding essential metals such as iron and calcium (6, 7). Polymeric polyphenols are also potent radical scavengers and antioxidants (8) and thus have been targeted as good candidates for therapeutic agents against diseases associated with oxidative stress. There are two classes of tannins that are of biological significance to humans; condensed and hydrolyzable tannins. Condensed tannins, or proanthocyanidins, can all be degraded to the pigments known as anthocyanidins. The flavanoid backbones of the condensed tannins are derived from phenylalanine and polyketide biosynthesis (9). The majority of condensed tannins are produced from the flavan-3-ols (+)-catechin (2,3-trans) and (-)-epicatechin (2,3-cis) (10). For example, procyanidin (PC) is a polymer of catechin and epicatechin subunits (Fig.1.1). Hydrolyzable tannins maintain a core polyol, usually glucose, with galloyl groups derived from shikimic acid esterified to the core (9). These tannins can polymerize through oxidative coupling of the galloyl groups resulting in complex structures known as ellagitannins. Pentagalloyl glucose (β-1,2,3,4,6- pentagalloyl-O-D-glucopyranose) or PGG, is one of the simplest gallotannins (Fig.1.1). 1 It consists of a glucose core with five galloyl groups linked to the five alcoholic positions on the pyranose ring by ester bonds (4). PGG is the polyphenol used in the experiments described in this thesis. 1.1.2. Human exposure to tannins Tannins, both condensed and hydrolyzable, are widely dispersed in the plant kingdom, with some plants containing as much as several grams of tannin per kilogram of tissue (2). Fruits such as blueberries and strawberries are some of the most commonly consumed tannin-containing foods in the American diet. Beverages such as red wine, cranberry juice, and apple juice contain approximately 750, 248, and 48 mg tannin per liter, respectively (2). It is estimated that tannin makes up somewhere between 37-56% of green tea constituents and that as much as 10% of black tea solids are made up of unoxidized catechins (11). Consumption of tannin-containing food products varies from region to region. Legumes and beans, staples in many countries, contain large quantities of condensed tannins (12, 13). Sorghum, which contains between 0.13-7.2% condensed tannin, is a common food staple in Asia, Africa, and countries in the Near and Middle East (14). The North American diet, which is relatively poor in grains, legumes and fruits, contains much less tannin. It has been reported that tannin consumption in India ranges from 1.5- 2.5 g/day, depending on the region, and about 1g/day within the USA (2). Tannins are important components of medicinal plants widely used in many cultures, particularly in Asia. For instance, shigyaku-san, used for gastritis and peptic ulcers in Japan, has the root of Paeonia among its many components. The outer skin of this root is also used to treat disorders of the cardiovascular system, such as high blood pressure. PGG is thought to be the biologically significant portion of that root (15). Polyphenolic compounds, when applied topically, may aid in wound healing, burns and inflammation by creating an impenetrable layer with protein or polysaccharide and therefore natural healing can occur underneath (5). Other plants reported to have medicinal properties, and that contain polyphenolic compounds include; Arctostaphylos uva-ursi, used as a diuretic for kidney disorders; Geranium maculatum, used as an anti- inflammatory agent and astringent; and Rubus idaeus or raspberry leaves, used for disorders of the stomach in children (5).
Load more

Recommended publications
  • Tannic Acid-Based Prepolymer Systems for Enhanced Intumescence in Epoxy Thermosets
    Cite this article Themed Issue: Sustainable flame Keywords: environmental impact/green Korey M, Johnson A, Webb W et al. (2020) retarded materials polymers/sustainable materials Tannic acid-based prepolymer systems for enhanced intumescence in epoxy thermosets. Paper 1900061 Green Materials 8(3): 150–161, Received 29/09/2019; Accepted 05/03/2020 https://doi.org/10.1680/jgrma.19.00061 Published online 06/04/2020 ICE Publishing: All rights reserved Green Materials Tannic acid-based prepolymer systems for enhanced intumescence in epoxy thermosets Matthew Korey Mark Dietenberger Graduate Research Assistant, Purdue University, West Lafayette, IN, USA Research General Engineer, Forest Products Laboratory, Madison, WI, USA (Orcid:0000-0002-2285-5646) Jeffrey Youngblood Alexander Johnson Professor, Purdue University, West Lafayette, IN, USA Undergraduate Research Assistant, Purdue University, West Lafayette, IN, USA (Orcid:0000-0002-8720-8642) William Webb John Howarter Staff, Career Academy, San Diego, CA, USA Associate Professor, Purdue University, West Lafayette, IN, USA (corresponding author: [email protected]) Tannic acid (TA) is a bio-based high-molecular-weight organic molecule. Although biologically sourced, TA is a pollutant in industrial wastewater streams, and there is desire to find applications in which to downcycle this molecule. Many flame retardants (FRs) used in epoxy are synthesized from petroleum-based monomers. Various bio-based modifiers have been developed, but increasing the flame retardancy of the system without trade-offs with other properties has proved challenging. In this work, TA is incorporated into the thermoset. The molecular behavior of the system was dependent on the TA loading, with low concentrations causing the molecule to be surface-functionalized, while at higher concentrations the molecule was cross-linked into the network.
    [Show full text]
  • Flavonoid-Modifying Capabilities of the Human Gut Microbiome—An in Silico Study
    nutrients Article Flavonoid-Modifying Capabilities of the Human Gut Microbiome—An In Silico Study Tobias Goris 1,* , Rafael R. C. Cuadrat 2 and Annett Braune 1 1 Research Group Intestinal Microbiology, Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany; [email protected] 2 Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany; [email protected] * Correspondence: [email protected] Abstract: Flavonoids are a major group of dietary plant polyphenols and have a positive health impact, but their modification and degradation in the human gut is still widely unknown. Due to the rise of metagenome data of the human gut microbiome and the assembly of hundreds of thousands of bacterial metagenome-assembled genomes (MAGs), large-scale screening for potential flavonoid-modifying enzymes of human gut bacteria is now feasible. With sequences of characterized flavonoid-transforming enzymes as queries, the Unified Human Gastrointestinal Protein catalog was analyzed and genes encoding putative flavonoid-modifying enzymes were quantified. The results revealed that flavonoid-modifying enzymes are often encoded in gut bacteria hitherto not considered to modify flavonoids. The enzymes for the physiologically important daidzein-to-equol conversion, well studied in Slackia isoflavoniconvertens, were encoded only to a minor extent in Slackia MAGs, but were more abundant in Adlercreutzia equolifaciens and an uncharacterized Eggerthellaceae species. In addition, enzymes with a sequence identity of about 35% were encoded in highly abundant MAGs of uncultivated Collinsella species, which suggests a hitherto uncharacterized daidzein-to-equol potential in these bacteria.
    [Show full text]
  • The Use of Plants in the Traditional Management of Diabetes in Nigeria: Pharmacological and Toxicological Considerations
    Journal of Ethnopharmacology 155 (2014) 857–924 Contents lists available at ScienceDirect Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jep Review The use of plants in the traditional management of diabetes in Nigeria: Pharmacological and toxicological considerations Udoamaka F. Ezuruike n, Jose M. Prieto 1 Center for Pharmacognosy and Phytotherapy, Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University College London, 29-39 Brunswick Square, WC1N 1AX London, United Kingdom article info abstract Article history: Ethnopharmacological relevance: The prevalence of diabetes is on a steady increase worldwide and it is Received 15 November 2013 now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of Received in revised form herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby 26 May 2014 carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on Accepted 26 May 2014 the available evidence on the species' pharmacology and safety, we highlight ways in which their Available online 12 June 2014 therapeutic potential can be properly harnessed for possible integration into the country's healthcare Keywords: system. Diabetes Materials and methods: Ethnobotanical information was obtained from a literature search of electronic Nigeria databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants Ethnopharmacology used in diabetes management, in which the place of use and/or sample collection was identified as Herb–drug interactions Nigeria. ‘Diabetes’ and ‘Nigeria’ were used as keywords for the primary searches; and then ‘Plant name – WHO Traditional Medicine Strategy accepted or synonyms’, ‘Constituents’, ‘Drug interaction’ and/or ‘Toxicity’ for the secondary searches.
    [Show full text]
  • RNA-Sequencing Analysis Reveals Betalains Metabolism in the Leaf of Amaranthus Tricolor L
    RESEARCH ARTICLE RNA-sequencing analysis reveals betalains metabolism in the leaf of Amaranthus tricolor L. Shengcai Liu1☯, Xueli Zheng1☯, Junfei Pan1, Liyun Peng1, Chunzhen Cheng1, Xiao Wang1, 1 1 1 1,2 1 Chunli Zhao , Zihao Zhang , Yuling Lin , Xu XuHan *, Zhongxiong LaiID * 1 Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China, 2 Institut de la Recherche Interdisciplinaire de Toulouse, Toulouse, France ☯ These authors contributed equally to this work. * [email protected](ZL); [email protected] (XXH) a1111111111 a1111111111 a1111111111 a1111111111 Abstract a1111111111 Amaranth plants contain large amounts of betalains, including betaxanthins and betacya- nins. Amaranthin is a betacyanin, and its molecular structure and associated metabolic pathway differ from those of betanin in beet plants. The chlorophyll, carotenoid, betalain, and flavonoid contents in amaranth leaves were analyzed. The abundance of betalain, beta- OPEN ACCESS cyanin, and betaxanthin was 2±5-fold higher in the red leaf sectors than in the green leaf Citation: Liu S, Zheng X, Pan J, Peng L, Cheng C, sectors. Moreover, a transcriptome database was constructed for the red and green sectors Wang X, et al. (2019) RNA-sequencing analysis of amaranth leaves harvested from 30-day-old seedlings. 22 unigenes were selected to ana- reveals betalains metabolism in the leaf of Amaranthus tricolor L.. PLoS ONE 14(4): lyze the expression profiles in the two leaf sectors. The RNA-sequencing data indicated that e0216001. https://doi.org/10.1371/journal. many unigenes are involved in betalain metabolic pathways. The potential relationships pone.0216001 between diverse metabolic pathways and betalain metabolism were analyzed.
    [Show full text]
  • Combinatorial Biosynthesis of Non-Bacterial and Unnatural Flavonoids, Stilbenoids and Curcuminoids by Microorganisms Sueharu Horinouchi
    J. Antibiot. 61(12): 709–728, 2008 THE JOURNAL OF REVIEW ARTICLE ANTIBIOTICS Combinatorial Biosynthesis of Non-bacterial and Unnatural Flavonoids, Stilbenoids and Curcuminoids by Microorganisms Sueharu Horinouchi Received: August 1, 2008 / Accepted: October 14, 2008 © Japan Antibiotics Research Association Abstract One of the approaches of combinatorial biosynthesis is combining genes from different organisms and designing a new set of gene clusters to produce bioactive compounds, leading to diversification of both chemical and natural product libraries. This makes efficient use of the potential of the host organisms, especially when microorganisms are used. An Escherichia coli system, in which artificial biosynthetic pathways for production of plant-specific medicinal polyketides, such as flavonoids, stilbenoids, isoflavonoids, and curcuminoids, are assembled, has been designed and expressed. Starting with amino acids tyrosine and phenylalanine as substrates, this system yields naringenin, resveratrol, genistein, and curcumin, for example, all of which are beneficial to human health because of their wide variety of biological activities. Supplementation of unnatural carboxylic acids to the recombinant E. coli cells carrying the artificial pathways by precursor-directed biosynthesis results in production of unnatural compounds. Addition of decorating or modification enzymes to the artificial pathway leads to production of natural and unnatural flavonols, flavones, and methylated resveratrols. This microbial system is promising for construction of larger libraries by employing other polyketide synthases and decorating enzymes of various origins. In addition, the concept of building and expressing artificial biosynthetic pathways for production of non-bacterial and unnatural compounds in microorganisms should be successfully applied to production of not only plant-specific polyketides but also many other useful compound classes.
    [Show full text]
  • Plant Phenolics: Bioavailability As a Key Determinant of Their Potential Health-Promoting Applications
    antioxidants Review Plant Phenolics: Bioavailability as a Key Determinant of Their Potential Health-Promoting Applications Patricia Cosme , Ana B. Rodríguez, Javier Espino * and María Garrido * Neuroimmunophysiology and Chrononutrition Research Group, Department of Physiology, Faculty of Science, University of Extremadura, 06006 Badajoz, Spain; [email protected] (P.C.); [email protected] (A.B.R.) * Correspondence: [email protected] (J.E.); [email protected] (M.G.); Tel.: +34-92-428-9796 (J.E. & M.G.) Received: 22 October 2020; Accepted: 7 December 2020; Published: 12 December 2020 Abstract: Phenolic compounds are secondary metabolites widely spread throughout the plant kingdom that can be categorized as flavonoids and non-flavonoids. Interest in phenolic compounds has dramatically increased during the last decade due to their biological effects and promising therapeutic applications. In this review, we discuss the importance of phenolic compounds’ bioavailability to accomplish their physiological functions, and highlight main factors affecting such parameter throughout metabolism of phenolics, from absorption to excretion. Besides, we give an updated overview of the health benefits of phenolic compounds, which are mainly linked to both their direct (e.g., free-radical scavenging ability) and indirect (e.g., by stimulating activity of antioxidant enzymes) antioxidant properties. Such antioxidant actions reportedly help them to prevent chronic and oxidative stress-related disorders such as cancer, cardiovascular and neurodegenerative diseases, among others. Last, we comment on development of cutting-edge delivery systems intended to improve bioavailability and enhance stability of phenolic compounds in the human body. Keywords: antioxidant activity; bioavailability; flavonoids; health benefits; phenolic compounds 1. Introduction Phenolic compounds are secondary metabolites widely spread throughout the plant kingdom with around 8000 different phenolic structures [1].
    [Show full text]
  • Biomolecules
    biomolecules Article Tannic Acid Improves Renal Function Recovery after Renal Warm Ischemia–Reperfusion in a Rat Model Louise Alechinsky 1, Frederic Favreau 2,3, Petra Cechova 4 , Sofiane Inal 1,5, Pierre-Antoine Faye 2,3, Cecile Ory 1, Raphaël Thuillier 1,5,6,7 , Benoit Barrou 1, Patrick Trouillas 8, Jerome Guillard 9 and Thierry Hauet 1,5,6,7,* 1 INSERM, U1082 IRTOMIT, 86021 Poitiers, France; [email protected] (L.A.); sofi[email protected] (S.I.); [email protected] (C.O.); [email protected] (R.T.); [email protected] (B.B.) 2 Université de Limoges, Faculté de Médecine, EA 6309 “Maintenance Myélinique et Neuropathies Périphériques”, 87025 Limoges, France; [email protected] (F.F.); [email protected] (P.-A.F.) 3 CHU de Limoges, Laboratoire de Biochimie et Génétique Moléculaire, 87042 Limoges, France 4 University Palacký of Olomouc, RCPTM, Dept Physical Chemistry, Faculty of Science, 771 46 Olomouc, Czech Republic; [email protected] 5 CHU de Poitiers, Laboratoire de Biochimie, 86021 Poitiers, France 6 Université de Poitiers, Faculté de Médecine et de Pharmacie, 86073 Poitiers, France 7 Département Hospitalo-Universitaire de Transplantation SUPORT, 86021 Poitiers, France 8 Inserm, UMR 1248, Fac. Pharmacy, Univ. Limoges, 87025 Limoges, France; [email protected] 9 Université de Poitiers, UMR CNRS 7285 IC2MP, Team 5 Organic Chemistry, 86073 Poitiers, France; [email protected] * Correspondence: [email protected] Received: 11 February 2020; Accepted: 9 March 2020; Published: 12 March 2020 Abstract: Background and purpose: Ischemia–reperfusion injury is encountered in numerous processes such as cardiovascular diseases or kidney transplantation; however, the latter involves cold ischemia, different from the warm ischemia found in vascular surgery by arterial clamping.
    [Show full text]
  • Fractionation of Orange Peel Phenols in Ultrafiltered Molasses and Mass Balance Studies of Their Antioxidant Levels
    7586 J. Agric. Food Chem. 2004, 52, 7586−7592 Fractionation of Orange Peel Phenols in Ultrafiltered Molasses and Mass Balance Studies of Their Antioxidant Levels JOHN A. MANTHEY† Citrus and Subtropical Products Laboratory, Southern Atlantic Area, Agricultural Research Service, U.S. Department of Agriculture, 600 Avenue S N.W., Winter Haven, Florida 33881 Orange peel molasses, a byproduct of juice production, contains high concentrations of phenols, including numerous flavanone and flavone glycosides, polymethoxylated flavones, hydroxycinnamates, and other miscellaneous phenolic glycosides and amines. Extensive fractionation of these phenols was achieved by adsorption, ion exchange, and size exclusion chromatography. Size exclusion chromatography effectively separated the different classes of flavonoids in ultrafiltered molasses, including the polymethoxylated flavones, flavanone-O-trisaccharides, flavanone- and flavone-O- disaccharides, and, finally, flavone-C-glycosides. Mass spectral analysis of the early-eluting flavonoid fractions off the size exclusion column revealed a broad collection of minor-occurring flavone glycosides, which included, in part, glycosides of limocitrin, limocitrol, and chrysoeriol. Most hydroxycinnamates in the molasses were recovered by ion exchange chromatography, which also facilitated the recovery of fractions containing many other miscellaneous phenols. Total antioxidant levels and total phenolic contents were measured for the separate categories of phenols in the molasses. Inhibition of the superoxide anion reduction of nitroblue tetrazolium showed that a significant amount of the total antioxidant activity in orange peel molasses was attributable to minor-occurring flavones. The miscellaneous phenolic-containing fractions, in which a large portion of the total phenolic content in molasses occurred, also constituted a major portion of the total antioxidants in ultrafiltered molasses.
    [Show full text]
  • Conductometric Study of the Acidity Properties of Tannic Acid (Chinese Tannin)
    Journal of the UniversityL. Costadinnova, of Chemical M. Hristova, Technology T. Kolusheva, and Metallurgy, N. Stoilova 47, 3, 2012, 289-296 CONDUCTOMETRIC STUDY OF THE ACIDITY PROPERTIES OF TANNIC ACID (CHINESE TANNIN) L. Costadinnova1, M. Hristova1, T. Kolusheva1, N. Stoilova2 1 University of Chemical Technology and Metallurgy Received 22 May 2012 8 Kl. Ohridski, 1756 Sofia, Bulgaria Accepted 12 June 2012 2 CLVCE, Department of VMP Analysis, 5 Iskarsko shose Blvd., Sofia, Bulgaria E-mail: [email protected] ABSTRACT Two tannic acids are studied (H T, n = 52), C H O , with average molar mass 1701.20 g mol-1. Using their UV and n 76 52 46 IR spectra it is shown that they have identical composition with respect to their functional groups, while by potentiometric and conductometric titration their structure of chinese tannin is verified and the relations between the acidity constants K > K K ... are determined. The absence of gallic acid is proved by HPLC. The conformational flexibility of the a1 a2 : a3 : tannin molecule is used to measure the stepwise constant K . By direct conductometry the acids were studied in the a1 concentration range of 5.00x10-4 to 5.00x10-2 mol l-1. The latter is determined from the Onsager-Shedlovsky relation. The molar conductivity of the ions − for the infinitely dilute solutions of the two tannic acids is found to be 55.2 and HTn1− 64.3 S L mol-1 cm-1. The degree of dissociation á in the studied concentration range varies from 0.03 to 0.3. The results for the acidity constant exponent pK are generalised using variance analysis, yielding ±∆ = ± , n = a1 pKa1 pK a1 4.19 0.02 26.
    [Show full text]
  • Flavonoids and Isoflavonoids Biosynthesis in the Model
    plants Review Flavonoids and Isoflavonoids Biosynthesis in the Model Legume Lotus japonicus; Connections to Nitrogen Metabolism and Photorespiration Margarita García-Calderón 1, Carmen M. Pérez-Delgado 1, Peter Palove-Balang 2, Marco Betti 1 and Antonio J. Márquez 1,* 1 Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Química, Universidad de Sevilla, Calle Profesor García González, 1, 41012-Sevilla, Spain; [email protected] (M.G.-C.); [email protected] (C.M.P.-D.); [email protected] (M.B.) 2 Institute of Biology and Ecology, Faculty of Science, P.J. Šafárik University in Košice, Mánesova 23, SK-04001 Košice, Slovakia; [email protected] * Correspondence: [email protected]; Tel.: +34-954557145 Received: 28 April 2020; Accepted: 18 June 2020; Published: 20 June 2020 Abstract: Phenylpropanoid metabolism represents an important metabolic pathway from which originates a wide number of secondary metabolites derived from phenylalanine or tyrosine, such as flavonoids and isoflavonoids, crucial molecules in plants implicated in a large number of biological processes. Therefore, various types of interconnection exist between different aspects of nitrogen metabolism and the biosynthesis of these compounds. For legumes, flavonoids and isoflavonoids are postulated to play pivotal roles in adaptation to their biological environments, both as defensive compounds (phytoalexins) and as chemical signals in symbiotic nitrogen fixation with rhizobia. In this paper, we summarize the recent progress made in the characterization of flavonoid and isoflavonoid biosynthetic pathways in the model legume Lotus japonicus (Regel) Larsen under different abiotic stress situations, such as drought, the impairment of photorespiration and UV-B irradiation. Emphasis is placed on results obtained using photorespiratory mutants deficient in glutamine synthetase.
    [Show full text]
  • Noncatalytic Chalcone Isomerase-Fold Proteins in Humulus Lupulus Are Auxiliary Components in Prenylated Flavonoid Biosynthesis
    Noncatalytic chalcone isomerase-fold proteins in Humulus lupulus are auxiliary components in prenylated flavonoid biosynthesis Zhaonan Bana,b, Hao Qina, Andrew J. Mitchellc, Baoxiu Liua, Fengxia Zhanga, Jing-Ke Wengc,d, Richard A. Dixone,f,1, and Guodong Wanga,1 aState Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101 Beijing, China; bUniversity of Chinese Academy of Sciences, 100049 Beijing, China; cWhitehead Institute for Biomedical Research, Cambridge, MA 02142; dDepartment of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139; eBioDiscovery Institute, University of North Texas, Denton, TX 76203; and fDepartment of Biological Sciences, University of North Texas, Denton, TX 76203 Contributed by Richard A. Dixon, April 25, 2018 (sent for review February 6, 2018; reviewed by Joerg Bohlmann and Mattheos A. G. Koffas) Xanthohumol (XN) and demethylxanthohumol (DMX) are special- braries have been deposited in the TrichOME database [www. ized prenylated chalconoids with multiple pharmaceutical appli- planttrichome.org (18)], and numerous large RNAseq datasets from cations that accumulate to high levels in the glandular trichomes different hop tissues or cultivars have also been made publically of hops (Humulus lupulus L.). Although all structural enzymes in available. By mining the hops transcriptome data, we and others have the XN pathway have been functionally identified, biochemical functionally identified several key terpenophenolic biosynthetic en- mechanisms underlying highly efficient production of XN have zymes from hop glandular trichomes (1, 18–23); these include car- not been fully resolved. In this study, we characterized two non- boxyl CoA ligase (CCL) genes and two aromatic prenyltransferase catalytic chalcone isomerase (CHI)-like proteins (designated as (PT) genes (HlPT1L and HlPT2) (22, 23).
    [Show full text]
  • Spinal Curaracardiac Poisons.Pdf
    STRYCHNOS NUX VOMICA KUCHILA Powerful alkaloids Strychnine and brucine ( 1& ½ %) Seeds also contain glucoside loganine Fruit hard, rough, glossy orange, 4‐5 cm wide, jelly like white or pale yellow pulp. It has 3‐5 seeds Strychnine occurs as colourless, odourless, rhombic prisms, having an intensely bitter taste The bark contains only brucine Fruit pulp ‐‐‐ low strychnine content Strychnine = 20 X brucine • Seeds are flat, circular discs or slightly convex on one side, concave on other side • 2.5 cm in diameter, 6mm in thickness • Ash grey or light brown in colour • Seeds are very hard, tough, difficult to pulverise • USES • In Chinese herbal medicine, the seeds of strychnine are eaten to alleviate external pains. • Different types of tumors as well as allay paralysis such as Bell’s palsy or facial paralysis. • Useful herbal medicine • Ingredient of homeopathic medication and is particularly recommended for digestive problems, feeling for cold as well as tetchiness. • As a respiratory stimulant • As a rodenticide • For killing stray dogs, even wild animals ABSORPTION AND EXCRETION All mm Much is taken by liver, muscle to be either released again into blood stream or to be destroyed This release produces convulsions on the 2nd or 3rd Day 80% is oxidised mainly in the liver Excreted slowly by the kidneys and traces in the bile, milk, saliva • ACTION • Competitively blocks ventral horn motor neuron postganglionic receptor sites in the spinal cord and prevent the effect of GLYCINE • Widespread inhibition in the spinal cord results in “release”
    [Show full text]