DOCSLIB.ORG

JWB Natural Products Final 2016.Pptx

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
JWB Natural Products Final 2016.Pptx Natural Product Chemistry II 1 Natural Product Chemistry II Four Lectures OH MeO O OMe N MeN O MeO O Ph OMe Me N OH H O H H OMe Synopsis: Recap of pyridoxal phosphate and biosynthesis of some amino acids; lysine and ornithine in biosynthesis of pyrrolidine and piperidine alkaloids; alkaloids derived from phenylalanine and tyrosine; benzylisoquinoline alkaloids; phenol oxidaon in the biosynthesis of complex alkaloids; classic examples of biomime<c synthesis ︎ Chemical Aspects of Biosynthesis, Oxford Chemistry Primer no. 20, John Mann The Organic Chemistry of Biological Pathways, John ︎ McMurry, Tadhg Begley ︎ Organic Chemistry, Jonathan Clayden, Nick Greeves, Stuart Warren, Peter Wothers, 1st Edi<on, Chapters 49, 50 and 51 ︎ Medicinal Natural Products – A Biosynthe<c Approach, 2nd Edi<on, Paul Dewick ︎ Biomime<c Organic Synthesis, Vols 1 & 2, Eds Erwan Poupon and Bas<en Nay [email protected] handout available at: hZp://burton.chem.ox.ac.uk/teaching.html Natural Product Chemistry II 2 ︎ Alkaloids ︎ Nitrogen containing secondary metabolites – non-pep<dic – non-nucleoside Me O N ︎ Named by Meissner as they were ‘like alkali’ H2N OH NH2 ︎ Mostly derived from α-amino acids ornithine O tropinone ︎ ornithine and lysine - aliphac alkaloids O H N O 2 OH ︎ phenyl alanine and tyrosine – aromac alkaloids NH N and aromac compounds in general 2 H lysine'('Lys'('K pelle$erine ︎ tryptophan – indole alkaloids O O OH MeO OH HN NH2 NH N HO 2 MeO tryptophan)*)Trp)*)W tyrosine)*)Tyr)*)Y OMe O OMe OH papaverine NH2 phenyl'alanine'*'Phe'*'F Natural Product Chemistry II 3 ︎ Biosynthesis of amino acids – amine transfer using pyridoxamine / pyridoxal phosphate and an aminotransferase Enz$B H R R CO H H O CO H 2 O R CO2H 2 Enz$B H H N H N P OH O O HO O NH2 O P OH P OH HO O HO O N Me O O H N Me N Me H H pyridoxal phosphate O R' CO2H R CO2H R' OH NH2 H N O O P OH NH2 H O HO O O O O P OH P OH HO O HO O N Me O O as lysine imine H N Me N Me H H hydrolysis O HO C HO C CO H 2 OH 2 2 O NH NH 2 O 2 α+ketoglutarate glutamic)acid P OH HO O R CO2H O + ︎ Overall transaminaon N Me O H ︎ Glutamate acts as nitrogen source – pyridoxamine phosphate nitrogen ini<ally introduced by reduc<ve aminaon of α-ketoglutarate ︎ Pyridoxal phosphate carried around as the lysine imine Natural Product Chemistry II 4 ︎ Pyridoxal phosphate mediates a number of other transformaons including racemisaon and decarboxylaon Enz$B Enz$B H H Me CO H 2 Me CO2H H O Me CO H O 2 H N H N P OH NH O O HO O 2 O P OH P OH HO O HO O N Me O O H N Me N Me natural (S)-L-alanine H H pyridoxal phosphate H Me CO2H H O O H N O P OH Me CO H hydrolysis HO O + 2 P OH O HO O N Me NH2 O H N Me H unnatural (R)-D-alanine Natural Product Chemistry II 5 ︎ Decarboxylaon O Enz$B H B-Enz R H R H H O O O R CO2H !"CO H N 2 H N P OH O O HO O NH2 O P OH P OH HO O HO O N Me O O H N Me H N Me pyridoxal phosphate H R H H O R H N O hydrolysis O + P OH NH P OH HO O 2 HO O O O N Me N Me H H O O NH 2 H N H2N NH2 H2N OH H2N 2 OH NH 2 NH2 ornithine putrescine lysine'('Lys'('K cadaverine As their names suggest, putrescine and cadaverine smell of rong flesh ︎ ︎ Other reac<ons mediated by pyridoxal phosphate include C-C bond formaon, subs<tu<on at the β-posi<on of α- amino acids, internal redox reac<ons between Cα and Cβ and between Cα and Cγ, oxidaon of a primary amine Natural Product Chemistry II 6 ︎ Biosynthesis of some amino acids O O O ATP HO C CO H HO C CO H P CO H NADH CO H 2 2 2 2 O O 2 H 2 NH2 O α!ketglutarate O O glutamate NH NH NH P OH 2 2 2 HO O spontaneous O O N Me SCoA H HO C CO H 2 2 N CO2H O HN O O P O NADH O ATP O P O O O O O P O N CO2H O P CO H O O 2 H O proline()(Pro()(P HN O NH R O 2 P OH ATP NADH HO O O O N Me CO H H CO H H 2 2 H2N HN O HN O H H O NH2 NH N CO H CO H urea H N 2 R H N N 2 2 2 cycle NH H NH 2 NADH 2 ornithine arginine'('Arg'('R Natural Product Chemistry II 7 ︎ Urea Cycle O H2N NH2 O O urea 2 HCO +)NH +)2ATP H N OPO 3 3 H2N OH 2 3 NH2 ornithine H2O O O H2N O H N N OH HN N OH 2 citrulline H NH H 2 NH2 arginine ATP HO2C CO2H fumarate HO2C O O%AMP O HN OH O HN N OH HN N OH H NH₂ H NH 2 O O NH H 2 N OH NH HO O O N N O aspar*c,acid H H uric(acid Natural Product Chemistry II 8 ︎ Biosynthesis of some amino acids O HO CO2H HO2C CO2H SCoA HO2C CO2H HO2C HO C CO2H 2 O CO2H citrate α!ketoglutarate and hydrolysis HO CO2H citric acid dehydraon CO2H cycle + H2O O O O HO C + OH SCoA 2 CO H HO C NAD 2 2 CO H HO C acetyl/CoA oxaloacetate 2 2 CO H CO H 2 (from/glycolysis) 2 NH2 O CO2H P OH -CO2 HO O ︎ Lysine is an essen<al amino acid O O N Me NH2 H HO2C HO C CO2H 2 CO2H ︎ Pathway from α-ketoglutarate is unique to fungi α!aminoadipate NH O 2 ATP P OH NADH HO O H O O O N Me NH H N O NH2 2 2 OH H H CO H N NH2 2 R lysine'('Lys'('K NAD+ Natural Product Chemistry II 9 ︎ Biosynthesis of some amino acids HO CO2H HO2C CO2H HO2C CO2H citrate α!ketoglutarate O citric acid NH O 2 cycle P OH HO O O O O NH2 ATP N Me HO C HO C NADH O NH2 2 H 2 CO H SCoA CO2H 2 H CO H acetyl/CoA oxaloacetate aspartate'('Asp'('D 2 (from/glycolysis) O O CO2H O O HO C SCoA 2 CO H CO H HO OH succinyl(CoA 2 NADH 2 O HN O N N NH O 2 P OH CO2H CO2H HO O O CO2H N Me H then hydrolysis H O O P OH O O HO O O O HO OH N Me H N H 2 OH NH NH 2 2 NH -CO2 2 meso!2,5!diaminopimelate lysine'('Lys'('K Natural Product Chemistry II 10 ︎ Aliphac alkaloids H O O H2N O H2N putrescine P OH HO O ︎ O Enz H ︎ O H2O CO2H N Me N N H2N ︎ H O O H N NH2 P OH P OH 2 HO O HO O ornithine O O ︎ N Me N Me N H H O MeHN P OH NMe HO O ︎ ︎ O NH H Enz N N Me O O H H -pyridoxamine P OH NMe HO O P OH ︎ HO O SAM O O N Me N Me Me SCoA H H CO H O O 2 acetoacetyl CoA H2N S R Me Me NMe NMe S!adenosyl*methionine ︎ ︎ N water -CO2 ︎ O SAM Me SCoA Me OH Me O O O O hygrine NH2 ︎ Also possible is methylaon of the cyclic imine formed aer release of pyridoxamine H2N putrescine ︎ In this example the reac<on does not proceed by way of symmetrical putrescine ︎ However, symmetrical putrescine is an intermediate in some plants (but not others) Natural Product Chemistry II 11 ︎ Aliphac alkaloids O SCoA [O] NMe NMe NMe NMe MeN SCoA SCoA SCoA O O SCoA O O O O O O O O SCoA hydrolysis malonyl'CoA O O decarboxylaon malonyl'CoA Me N O SCoA O MeN Me O hygrine hydrolysis O OMe O O OMe O OMe O OH CoAS MeN O Ph MeN NADH SAM OH MeN MeN H O H O O cocaine Natural Product Chemistry II 12 ︎ Aliphac alkaloids – tropinone and tropine [O] hydrolysis NMe NMe NMe NMe NMe SCoA SCoA SCoA O O SCoA O O O O O O O O O O SCoA hydrolysis malonyl'CoA O O decarboxylaon malonyl'CoA Me O O N O MeN MeN OH H Me O O hygrine P-450 O NADH (-)-hyoscyamine OH CoAS MeN NADH MeN H OH O H NADH MeN HO OH O OH O RO O H V tropine tropinone liorine O Fe Enz O IV Enz Fe OH • OH HO OH RO RO • RO O O O• Natural Product Chemistry II 13 ︎ Robinson’s synthesis of tropinone – R.
Load more

Recommended publications
  • Metabolomics Reveals the Molecular Mechanisms of Copper Induced
    Article Cite This: Environ. Sci. Technol. 2018, 52, 7092−7100 pubs.acs.org/est Metabolomics Reveals the Molecular Mechanisms of Copper Induced Cucumber Leaf (Cucumis sativus) Senescence † ‡ § ∥ ∥ ∥ Lijuan Zhao, Yuxiong Huang, , Kelly Paglia, Arpana Vaniya, Benjamin Wancewicz, ‡ § and Arturo A. Keller*, , † Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, China ‡ Bren School of Environmental Science & Management, University of California, Santa Barbara, California 93106-5131, United States § University of California, Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106, United States ∥ UC Davis Genome Center-Metabolomics, University of California Davis, 451 Health Sciences Drive, Davis, California 95616, United States *S Supporting Information ABSTRACT: Excess copper may disturb plant photosynthesis and induce leaf senescence. The underlying toxicity mechanism is not well understood. Here, 3-week-old cucumber plants were foliar exposed to different copper concentrations (10, 100, and 500 mg/L) for a final dose of 0.21, 2.1, and 10 mg/plant, using CuSO4 as the Cu ion source for 7 days, three times per day. Metabolomics quantified 149 primary and 79 secondary metabolites. A number of intermediates of the tricarboxylic acid (TCA) cycle were significantly down-regulated 1.4−2.4 fold, indicating a perturbed carbohy- drate metabolism. Ascorbate and aldarate metabolism and shikimate- phenylpropanoid biosynthesis (antioxidant and defense related pathways) were perturbed by excess copper. These metabolic responses occur even at the lowest copper dose considered although no phenotype changes were observed at this dose. High copper dose resulted in a 2-fold increase in phytol, a degradation product of chlorophyll.
    [Show full text]
  • I (Theoretical Organic Chemistry-I)
    M.Sc. Organic Chemistry Semester – III Course Code: PSCHO301 Paper - I (Theoretical organic chemistry-I) Unit 1 Organic reaction mechanisms [15L] 1.1 Organic reactive intermediates, methods of generation, structure, stability [5L] and important reactions involving carbocations, nitrenes, carbenes, arynes and ketenes. 1.2 Neighbouring group participation: Mechanism and effects of anchimeric [3L] assistance, NGP by unshared/ lone pair electrons, π-electrons, aromatic rings, σ-bonds with special reference to norbornyl and bicyclo[2.2.2]octyl cation systems (formation of non-classical carbocation) 1.3 Role of FMOs in organic reactivity: Reactions involving hard and soft [2L] electrophiles and nucleophiles, ambident nucleophiles, ambident electrophiles, the α effect. 1.4 Pericyclic reactions: Classification of pericyclic reactions; thermal and [5L] photochemical reactions. Three approaches: Evidence for the concertedness of bond making and breaking Symmetry-Allowed and Symmetry-Forbidden Reactions – The Woodward-Hoffmann Rules-Class by Class The generalised Woodward-Hoffmann Rule Explanations for Woodward-Hoffmann Rules The Aromatic Transition structures [Huckel and Mobius] Frontier Orbitals Correlation Diagrams, FMO and PMO approach Molecular orbital symmetry, Frontier orbital of ethylene, 1,3 butadiene, 1,3,5 hexatriene and allyl system. Unit 2 Pericyclic reactions [15L] 2.1 Cycloaddition reactions: Supra and antra facial additions, 4n and 4n+2 [7L] systems, 2+2 additions of ketenes. Diels-Alder reactions, 1, 3-Dipolar cycloaddition and cheletropic reactions, ene reaction, retro-Diels-Alder reaction, regioselectivity, periselectivity, torquoselectivity, site selectivity and effect of substituents in Diels-Alder reactions. Other Cycloaddition Reactions- [4+6] Cycloadditions, Ketene Cycloaddition, Allene Cycloadditions, Carbene Cycloaddition, Epoxidation and Related Cycloadditions. Other Pericyclic reactions: Sigmatropic Rearrangements, Electrocyclic Reactions, Alder ‘Ene’ Reactions.
    [Show full text]
  • Effects of A-Aminooxy-ß-Phenylpropionic Acid on Phenylalanine Metabolism in /R-Fluorophenylalanine Sensitive and Resistant Toba
    Effects of a-Aminooxy-ß-phenylpropionic Acid on Phenylalanine Metabolism in /r-Fluorophenylalanine Sensitive and Resistant Tobacco Cells Jochen Berhn and Brigitte Vollmer Lehrstuhl fur Biochemie der Pflanzen, Westfälische Wilhelms-Universität Münster, West Germany Z. Naturforsch. 34 c, 770 — 775 (1979); received May 18, 1979 Nicotiana tabacum, Suspension Cultures, a-Aminooxy-ß-phenylpropionic Acid, Chorismate Mu- tase, Phenylalanine, Pool Sizes A ^-fluorophenylalanine (PFP) resistant cell line with high phenylalanine ammonia lyase (PAL) activity and wild type cells with low PAL activity were compared in their responses to PAL inhibition by a-aminooxy-/?-phenylpropionic acid (AOP). Inhibition of PAL reduced the levels of the main phenolic compounds to 30% of the controls. Free phenylalanine pools increased 17 fold in the resistant line and 6 fold in the sensitive line, respectively. The accumulation of phenylalani­ ne did not reduce the flow of labeled shikimic acid into the aromatic amino acids tyrosine and phenylalanine. The results are discussed with respect to the feedback inhibition of chorismate mu- tase activity by phenylalanine and tyrosine in both cell lines. Amino acid analog resistant cell lines normally Therefore the cells were grown in the presence of a have an increased pool size of the corresponding na­ specific inhibitor of PAL, a-aminooxy-yß-phenyl- tural amino acid due to a lessened feedback control propionic acid (AOP) [ 6 ], Inhibition of PAL should in the biosynthetic pathway [1]. A tobacco cell line result in distinct changes of phenylalanine pools in resistant to / 7-fluorophenylalanine (PFP), however, sensitive and resistant cells and/or should reduce the did not fit into this frame [2-5], The main reason for flow of carbon through the shikimate pathway.
    [Show full text]
  • 102 4. Biosynthesis of Natural Products Derived from Shikimic Acid
    102 4. Biosynthesis of Natural Products Derived from Shikimic Acid 4.1. Phenyl-Propanoid Natural Products (C6-C3) The biosynthesis of the aromatic amino acids occurs through the shikimic acid pathway, which is found in plants and microorganisms (but not in animals). We (humans) require these amino acids in our diet, since we are unable to produce them. For this reason, molecules that can inhibit enzymes on the shikimate pathway are potentially useful as antibiotics or herbicides, since they should not be toxic for humans. COO COO NH R = H Phenylalanine 3 R = OH Tyrosine R NH3 N Tryptophan H The aromatic amino acids also serve as starting materials for the biosynthesis of many interesting natural products. Here we will focus on the so-called phenyl-propanoide (C6-C3) natural products, e.g.: OH OH OH HO O HO OH HO O Chalcone OH O a Flavone OH O OH O a Flavonone OH OH Ar RO O O O HO O O OH O OR OH Anthocyanine OH O a Flavonol Podophyllotoxin MeO OMe OMe OH COOH Cinnamyl alcohol HO O O Cinnamic acid OH (Zimtsäure) Umbellierfone OH a Coumarin) MeO OH O COOH HO Polymerization OH Wood OH HO OH O OH MeO OMe Shikimic acid O HO 4.2. Shikimic acid biosynthesis The shikimic acid pathway starts in carbohydrate metabolism. Given the great social and industrial significance of this pathway, the enzymes have been intensively investigated. Here we will focus on the mechanisms of action of several key enzymes in the pathway. The following Scheme shows the pathway to shikimic acid: 103 COO- COO- Phosphoenolpyruvate HO COO- 2- O O3P-O 2- O3P-O DHQ-Synthase
    [Show full text]
  • Development of an Assay for a Diels-Alderase Enzyme
    Development of an Assay for a Diels-Alderase Enzyme A Thesis submitted in part fulfilment of the requirements of the degree of Doctor of Philosophy Graeme Douglas McAllister Department of Chemistry University of Glasgow Glasgow G12 8QQ February 2000 ©Graeme D. McAllister ProQuest Number: 13818648 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 13818648 Published by ProQuest LLC(2018). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 Dedicated to iny family "Do they give Nobel prizes for attempted chemistry? Do they!?" from 'The Simpsons' by Matt Groening Acknowledgements First of all my sincerest thanks go to my supervisor, Dr Richard Hartley, for his expert guidance over the last 3 years. I would also like to thank Dr Mike Dawson and Dr Andy Knaggs of GlaxoWellcome for their supervision and ideas in the biological areas of this project, and for helping a chemist adjust to life in a biology lab! Dr Chris Brett of the University of Glasgow and Mrs Jyoti Vithlani of GlaxoWellcome deserve a mention for all their expertise in the growing of cell cultures and for helping me in the feeding studies.
    [Show full text]
  • 8.2 Shikimic Acid Pathway
    CHAPTER 8 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FORAromatic SALE OR DISTRIBUTION and NOT FOR SALE OR DISTRIBUTION Phenolic Compounds © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION CHAPTER OUTLINE Overview Synthesis and Properties of Polyketides 8.1 8.5 Synthesis of Chalcones © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC 8.2 Shikimic Acid Pathway Synthesis of Flavanones and Derivatives NOT FOR SALE ORPhenylalanine DISTRIBUTION and Tyrosine Synthesis NOT FOR SALESynthesis OR DISTRIBUTION and Properties of Flavones Tryptophan Synthesis Synthesis and Properties of Anthocyanidins Synthesis and Properties of Isofl avonoids Phenylpropanoid Pathway 8.3 Examples of Other Plant Polyketide Synthases Synthesis of Trans-Cinnamic Acid Synthesis and Activity of Coumarins Lignin Synthesis Polymerization© Jonesof Monolignols & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Genetic EngineeringNOT FOR of Lignin SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Natural Products Derived from the 8.4 Phenylpropanoid Pathway Natural Products from Monolignols © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 119 © Jones & Bartlett Learning, LLC.
    [Show full text]
  • The Role of Shikimic Acid in Regulation of Growth, Transpiration, Pigmentation, Photosynthetic Activity and Productivity of Vigna Sinensis Plants
    ZOBODAT - www.zobodat.at Zoologisch-Botanische Datenbank/Zoological-Botanical Database Digitale Literatur/Digital Literature Zeitschrift/Journal: Phyton, Annales Rei Botanicae, Horn Jahr/Year: 2000 Band/Volume: 40_2 Autor(en)/Author(s): Aldesuquy Heshmat S., Ibrahim A. H. A. Artikel/Article: The Role of Shikimic Acid in Regulation of Growth, Transpiration, Pigmentation, Photosynthetic Activity and Productivity of Vigna sinensis Plants. 277-292 ©Verlag Ferdinand Berger & Söhne Ges.m.b.H., Horn, Austria, download unter www.biologiezentrum.at Phyton (Horn, Austria) Vol. 40 Fasc. 2 277-292 27. 12. 2000 The Role of Shikimic Acid in Regulation of Growth, Transpiration, Pigmentation, Photosynthetic Activity and Productivity of Vigna sinensis Plants By H. S. ALDESUQUY*) & A. H. A. IBRAHIM*) With 4 figures Received February 2, 2000 Accepted May 31, 2000 Key words: 14C-assimilation, pigments, shikimic acid, total leaf conductivity, transpiration, yield. Summary ALDESUQUY H. S. & IBRAHIM A. H. A. 2000. The role of shikimic acid in regulation of growth, transpiration, pigmentation, photosynthetic activity and productivity of Vigna sinensis plants. - Phyton (Horn, Austria) 40 (2): 277-292, with 4 figures. - English with German summary. The effect of shikimic acid on growth parameters, total leaf conductivity, tran- spiration, photosynthetic pigments, 14C assimilation and productivity of Vigna si- nensis (Fabaceae - Phaseoleae) plants was studied. Shikimic acid application led to an increase in fresh and dry weights of cowpea plants and enhances leaf expansion as well as the root length and plant height. Seed pretreatment with shikimic acid at various doses induces a marked in- crease in total leaf conductivity and transpiration rate at different stages of growth.
    [Show full text]
  • 357 Ruminal Biosynthesis of Aromatic Amino Acids from Arylacetic Acids
    Downloaded from 357 https://www.cambridge.org/core Ruminal biosynthesis of aromatic amino acids from arylacetic acids, glucose, shikirnic acid and phenol BY S. KRISTENSEN Organic Chemical Laboratory, Royal Veterinary and Agricultural University, Copenhagen, Denmark . IP address: (Received 19 July 1973 - Accepted 15 October 1973) 170.106.33.14 I. Ruminal metabolism of labelled phenylacetic acid, 4-hydroxyphenylacetic acid, indole- 3-acetic acid, glucose, shikimic acid,, phenol, and serine was studied in vitro by short-term incubation with special reference to incorporation rates into aromatic amino acids. 2. Earlier reports on reductive carboxylation of phenylacetic acid and indole-3-acetic , on acid in the rumen were confirmed and the formation of tyrosine from 4-hydroxyphenylacetic 02 Oct 2021 at 07:13:11 acid was demonstrated for the first time. 3. The amount of pllenylulanine synthesized from phenylacetic acid was estimated to be 2 mg/l rumen contents pcr 24 h, whereas the amount synthesized from glucose might be eight times as great, depending on diet. 4. Shikimic acid was a poor precursor of the aromatic amino acids, presumably owing to its slow entry into rumen bacteria. 5. A slow conversion of phenol into tyrosine was observed. , subject to the Cambridge Core terms of use, available at The mechanisms of biosynthesis of rumen amino acids have been reviewed by Allison (1969). Most of these conform to known pathways, but new pathways have been established for the biosynthesis of glutamate (Emmanuel & Milligan, 197z), the branched-chain amino acids (Allison & Bryant, 1963), phenylalanine, and tryptophan (see below). It has been shown that all these substances are synthesized by reduction, carboxylation, and amination of their corresponding fatty acids with one carbon less.
    [Show full text]
  • The PLANT PHENOLIC COMPOUNDS Introduction & the Flavonoids the Plant Phenolic Compounds - 8,000 Phenolic Structures Known
    The PLANT PHENOLIC COMPOUNDS Introduction & The Flavonoids The plant phenolic compounds - 8,000 Phenolic structures known - Account for 40% of organic carbon circulating in the biosphere - Evolution of vascular plants: in cell wall structures, plant defense, features of woods and barks, flower color, flavors The plant phenolic compounds They can be: Simple, low molecular weight, single aromatic ringed compounds TO- Large and complex- polyphenols The Plant phenolic compounds The plant phenolic compounds - Primarily derived from the: Phenylpropanoid pathway and acetate pathway (and related pathways) Phenylpropanoid pathway and phenylpropanoid- acetate pathway Precursors for plant phenolic compounds The phenylpropanoids: products of the shikimic acid pathway The phenylpropanoids: products of the shikimic acid pathway (phe and tyr) THE PHENYLPROPANOIDS: PRODUCTS OF THE SHIKIMIC ACID PATHWAY (phe & tyr) The shikimate pathway The plant phenolic compounds - As in other cases of SMs, branches of pathway leading to biosynthesis of phenols are found or amplified only in specific plant families - Commonly found conjugated to sugars and organic acids The plant phenolic compounds Phenolics can be classified into 2 groups: 1. The FLAVONOIDS 2. The NON-FLAVONOIDS The plant phenolic compounds THE FLAVONOIDS - Polyphenolic compounds - Comprise: 15 carbons + 2 aromatic rings connected with a 3 carbon bridge The Flavane Nucleus THE FLAVONOIDS - Largest group of phenols: 4500 - Major role in plants: color, pathogens, light stress - Very often in epidermis of leaves and fruit skin - Potential health promoting compounds- antioxidants - A large number of genes known THE Flavonoids- classes Lepiniec et al., 2006 THE Flavonoids - The basic flavonoid skeleton can have a large number of substitutions on it: - Hydroxyl groups - Sugars - e.g.
    [Show full text]
  • Of Glyphosate Resistance in a Selected Plantago Lanceolata (L.) R Biotype
    agronomy Article Mechanism(s) of Glyphosate Resistance in a Selected Plantago lanceolata (L.) R Biotype Vhuthu Ndou 1,* , Petrus Jacobus Pieterse 1 , Dirk Jacobus Brand 2 , Alvera Vorster 3, Amandrie Louw 4 and Ethel Phiri 1 1 Department of Agronomy, University of Stellenbosch, Stellenbosch 7600, South Africa; [email protected] (P.J.P.); [email protected] (E.P.) 2 NMR Unit, Central Analytical Facility, Department of Chemistry and Polymer Science, University of Stellenbosch, Stellenbosch 7600, South Africa; [email protected] 3 DNA Unit, Central Analytical Facility, DNA Sequencer, University of Stellenbosch, Stellenbosch 7600, South Africa; [email protected] 4 Department of Conservation Ecology and Entomology, University of Stellenbosch, Stellenbosch 7600, South Africa; [email protected] * Correspondence: [email protected] Abstract: In 2003, a glyphosate-resistant plantago (Plantago lanceolata L.) population located in the Robertson district of South Africa was subjected to different glyphosate dosages and the highest dosage (7200 g a.e. ha−1) gave no acceptable levels of control. Here we reconfirm resistance and investigate the mechanism of glyphosate resistance. Dose-response curves indicated that the glyphosate dosage rate causing 50% survival (LD ) for the resistant (R) biotype is 43 times greater 50 than for the susceptible (S) biotype, i.e., 43-fold resistant to glyphosate. Investigation into the Citation: Ndou, V.; Pieterse, P.J.; molecular mechanism of plantago showed shikimate accumulation of the R biotype was lower than Brand, D.J.; Vorster, A.; Louw, A.; that of the S biotype. The reported 31P and 13C nuclear magnetic resonance (NMR) spectra show Phiri, E.
    [Show full text]
  • Shikimic Acid (Tamiflu Precursor) Production in Suspension Cultures of East Indian Sandalwood (Santalum Album) in Air-Lift Bioreactor Biswapriya B
    PostDoc Journal Journal of Postdoctoral Research Vol. 1, No. 1, January 2013 www.postdocjournal.com Shikimic Acid (Tamiflu Precursor) Production in Suspension Cultures of East Indian Sandalwood (Santalum album) in Air-lift Bioreactor Biswapriya B. Misra1, 2, * and Satyahari Dey1 1Plant Biotechnology Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur, Midnapore (West), Kharagpur-721302, West Bengal, India 2Center for Chemical Biology, Universiti Sains Malaysia (CCB@USM), 1st Floor Block B, No 10, Persiaran Bukit Jambul, 11900 Bayan Lepas, Pulau Pinang, Malaysia *Email: [email protected] Abstract Shikimic acid is the key precursor for industrial synthesis of the potent neuraminidase inhibitor, oseltamivir (Tamiflu) that has tremendous importance in the treatment of flu. Plant and microbial sources are the only sources of shikimic acid. We report, suspension cultures of Indian Sandalwood tree (Santalum album L.) grown in air-lift bioreactor and shake-flask cultures as alternative and renewable resource of shikimic acid. Hot aqueous and ethanolic preparations of biomass and spent media yielding shikimic acid and quinic acid were further characterized by TLC and LC-ESI-MS/ MS analyses. Suspension cultures in Erlenmeyer shake flask and air-lift bioreactor of 50 mL and 2 L volumes, yielded 0.07 and 0.08 % (w/w) shikimic acid, respectively, in 2-3 weeks. Significantly, we propose that alternative plant cell cultures, sans rigorous genetic manipulation can be exploited commercially for shikimic acid production. Highlights Introduction • Shikimic acid, the sole molecule used in Shikimic acid (3,4,5-trihydroxy-1-cyclohexene-1- industrial synthesis for commercial production of carboxylic acid) (Eijkman, 1985), is a high value Tamiflu has limited sources.
    [Show full text]
  • Shikimic Acid Group Meeting Narendra Ambhaikar 1/12/2005
    Shikimic acid Group Meeting Narendra Ambhaikar 1/12/2005 Biosynthetic pathway OPO3H2 HO CO H OH 2 OH OH CO2H O O phosphoenolpyruvic OH OH acid CO2H OH OH OH OH O OPO3H2 H2O3PO 3-deoxy-D-arabino- glucose H heptulosonic acid phosphate HO OH OH OH D-erythrose 4-phosphate (E4P) (-)-shikimic acid CO2H HO CO2H OH OH -Shikimic acid is a hydroaromatic intermediate in the common pathway of aromatic O OH O OH amino acid biosynthesis. OH OH 3-dehydroshikimic acid -First isolated in 1885 by Eykman from the fruit of Illicium religiosum. Found to exist 3-dehydroquinic acid widely in leaves of fruit of many plants and also in microorganisms, but in limited CO H CO H quantities. 2 2 HO CO2H -Relative and absolute stereochemistry realized only in 1930s through the works of Fischer, Freudenberg and Karrer. HO OH H2O3PO OH HO OH OH OH OH -It is mainly involved in the biosynthetic shikimate pathway operative in plants and (-)-shikimic acid shikimate 3-phosphate (-)-quinic acid microorganisms and discovered by Davis, Sprinson and Gibson. Three amino acids (L-phenylalanine, L-tyrosine and L-tryptophan) are synthesized along the pathway. Some molecules synthesized Some molecules synthesized from (-)-shikimic acid from (-)-quinic acid H -Available commercially (from Aldrich $58.00 per gram). Limited availability from HO OBz N H plants has led to the discovery of other synthetic and biosynthetic means to obtain HO O H N N 2 N Br shikimic acid. Recently reported to be derived from microbial fermentation of glucose O CO2Et using recombinant E.
    [Show full text]