DOCSLIB.ORG

Corrin Chemistry: from B to the Origin of Life

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Corrin Chemistry: from B to the Origin of Life N. Z. Burns Corrin Chemistry: from B12 to the Origin of Life Corrin: Vitamin B12 x-ray structure: 3 5 4 2 Name "corrin" proposed by those who A B established its structure because it is 1 N HN 9 the core of the vitamin B12 molecules. 19 N N D C The most ancient of the uroporphinoids: 15 the primitive anaerobes which make B12 9 C19H22N4 can be dated back 3.79 x 10 years. Some Uroporphinoids: NH HN N HN N HN N N corrole tetrahydrocorphin: coenzyme F430 Structure: Crowfoot-Hodgkin 1955 (1964 Chemistry Nobel Prize) N HN N HN One of the "finest contributions of British NH N NH N science to the chemistry of low-molecular- weight natural products" -A. Eschenmoser chlorin: porphyrin: chlorophyll heme 1 Nature, 1955, 176, 325. N. Z. Burns Corrin Chemistry H2NOC Eschenmoser's cobyric Me acid synthesis: H Me CONH2 H2NOC H Me Me H CONH2 H2NOC A CN B Me N N N N Me H Co CONH2 H NOC R H 2 Me N N Bernhauer N N N Me N H2NOC CN Me Co CONH2 vitamin B12 D C H HO H NH 1960 Me N N Me 2 Me H2NOC R = O H H Me Me HO H CONH2 Me Me CONH2 O OH O Me coenzyme B12 cobyric acid N MeO C NH 2 O Me HO N R = CN vitamin B H Me CO2Me H 12 Me O Me O H S O P O A Me B O NH HN H O H H MeO C 2 HO2C S OH NC Me Me H O O Me CO2H O O Me O + Me Me O O O O H Me HO C H N 2 HN MeO2C C Me D Br "Of all that architecture and organic synthesis have in common, one thing is O Me this: for the works of both, explicit goals are usually set, but after the works H are done, their raison d'être often lies within themselves." Me – A. Eschenmoser, Robert Robinson Lecture 1976 CN CO2Me 2 Science, 1977, 196, 1410; Classics in Total Synthesis N. Z. Burns Corrin Chemistry O O Me H CO2Me O O Me O B H CO2Me Me N Me HN S N O Me C Me benzoyl peroxide, (EtO)3P, xylene H + O Me B Me HN HN H HCl, CH Cl 125 °C HN Me 2 2 O C Me CO Me 2 (85% overall) Me H O S CO2Me Me H CO2Me CO2Me MeO C H N 2 D Br D P2S5, 4-methylpyridine, xylene, 130 °C (84%) Me CN O O I CONMe2 Me S Me S Me H CO2Me H H 1. MeNH , Me 1. t-BuOK, t-BuOH, Me N 2 N N MeOH, 25 ˚C THF, 25 °C; D CO2Me CO2Me MeO2C H H N HN Me N HN Me HN Me 2. N-iodosuccinimide 2. (NC(CH2)2)3P, Me CH2Cl2, 0 ˚C Me TFA, sulfolane, Me MeO2C S Me H Me H 60 °C H (64% overall) CN CO2Me CN CO2Me CO2Me 3 N. Z. Burns Corrin Chemistry MeO2C Me CONMe2 MeO2C H S Me H H CONMe2 1. A, NaHMDS, CO Me 1. Ph3P, TFA, MeO2C N 2 PhH, 25 °C N PhH, 80 °C H Me MeO C Me Cd(Cl) 2 N N NC Me 2. Cd(ClO4)2, 2. Cd(ClO4)2, i-Pr2NEt, Cd(Cl) CO Me N N Me 2 MeOH, 25 °C MeO C PhH, MeOH, 25 °C 2 N N Me H Me then NaCl workup MeO2C H Me Me (46% overall) H 3. DBU, sulfolane, 60 °C Me H CN CO2Me MeO2C CN CO2Me H Me S 1. hν (visible), 60 °C A NH A 2. CoCl2, 58 °C MeO2C 3. KCN, air, H2O, NC Me CH2Cl2, 0 °C (46% overall) MeO2C Me H CONMe2 H CO2Me MeO C CN N N N 2 N N N N N Me H hν Me H Co H H N H N N N N N N N Me H MeO2C CN H H Me Me H CN CO2Me 4 N. Z. Burns Corrin Chemistry MeO2C A solution to meso methyl introduction: Me Jacobi, JOC, 1999, 64, 1778 H Me CO2Me 1. I2, AcOH H Me 2. ClCH2OCH2Ph Me MeO2C CN Me Me sulpholane, 75 °C Me N N Me Me Co CO Me H 2 O NC 3. PhSH HO 0 N N N Me Me 1. Pd , R4NCl, Hün. 4. Raney Ni; CH N MeO2C CN 2 2 H + Me 5. conc. H2SO4 Me Me Me Cl 2. NH3, (63%) HN H Me Me Me N O Me CONH CO Me NC 2 2 Me Cl Cy + CCl4, PPh3 (72%) N then H3O ; Me2NH (57%) Me AgBF4 O Me Me Me Me NC O Me MeO2C Me N 1. H2N Me Me Me Pd0, CuI, Et N NC H CO2Me O Me 3 (69%) N H NH N NH (l), MeO2C CN Me Me 3 Me N N + HO(CH ) OH, Me 2. H (83%) N 2 2 Me Co CO Me Me Me cobyric H 2 Me acid N N Me Cl Me NH4Cl, 75 °C MeO2C CN (64%) H Me Me H Me For a particularly elegant approach to Vitamin B12 by R. V. CO Me CO2H 2 Stevens see "Isoxazoles and Isothiazoles in Synthesis" (Mitsos, 2004) 5 N. Z. Burns Corrin Chemistry Synthetic Analysis of Specific Structural Elements of Synthetic Analysis of Specific Structural Elements Vitamin B12: Towards a Chemical Rationalization of Structure H2NOC Me H Me CONH2 "Can work done on the chemical synthesis of vitamin B12 be extended to make a H contribution to the problem of vitamin B12 biosynthesis? This question began to H2NOC CN motivate and direct our activity in the field of corrin chemistry soon after the smoke Me N N on the battlefield of total synthesis had disappeared." Me Co CONH2 H N N Me H2NOC H Me "[An] objective that can and should be studied with the tools of natural product H synthesis [is a] systematic delimitation of the boundary separating the reactivity of Me Me CONH2 biomolecules from structural changes." O Me N NH Me HO N "Can experiments aimed at a deeper understanding of the molecular structure H of cofactors tell us something about that early phase of biological evolution?" Me O H O P O O O H H OH Darwinian paradigm of molecular evolution: structure a result of selection • specific arrangement of double bonds in corrin chromophore • contracted dimension compared with corphin ring • specific attachment of nucleotide ligand to ring D structural preformation selection emergence of biosynthetic pathway • arrangement of substituents on the ligand periphery mutations biotic prebiotic "Chemists engaged in natural product synthesis are probably in the best position to grasp the vast number as well as the nature of lucky prerequisites that must be fulfilled reproduction feedback for a multistep biosynthesis of a complex natural product to emerge." Eschenmoser, ACIEE, 1988, 27, 5. 6 N. Z. Burns Corrin Chemistry Specific arrangement of double bonds in corrin chromophore Et Et Et Et What is the position of the tautomeric equilibrium between the tetrapyrrolic MgI arrangement of double bonds in a porphyrinogen and the arrangement in its N N corphinoid counterpart? Et Et Et Et NH HN N N N Mg NH HN xylene, 85 ˚C N N Et Et ~ quant. Et Et NH HN ? N HN Et Et Et Et NH HN N N CH3I/PhH ∆ (~90%) MgBr2 moist PhH porphyrinogen corphin: Pyr•HOAc corrin-like chromophore ~ quant. Et Et Et Et Et Et Et Et R R R R N N N N R R R R XMg XMg NH HN N HN N N N N Et Et Et Et Et Et Me Et H Et corrinoid chromophore Metal ion R R R R R R R R N N N N • In complexed form, thermodynamic equilibrium of tautomers favors M M the corrinoid system • Analogous reactivity seen with Zn(II) and Ni(II) complexes 7 ACIEE, 1983, 22, 630 & 632 N. Z. Burns Corrin Chemistry Contracted dimension of the corrin ring Since the coordination hole of corrinoid ligands is better suited to Unfavorable "ligand ruffling" observed in hydroporphinoid metal complexes that is not seen in the corresponding corrinoids: the spatial demands of the metal(II) ion a corphinoid to corrinoid rearrangement should be possible: Me Me Me Me Me Me Me Me Me Me Me Me N N N R N N R N Me Me 260 ˚C, 5 min Me Ni Me Co O Co N N HO N R N ≤ 40% N R N Me Me Me Me Me Ni–N = 1.863 Å Me Me Me Me Me Me Me Me R = CN Et Et Proc. Natl. Acad. Sci. 1981, 78, 16. Et Et N N H Specific attachment of nucleoside ligand to ring D Ni N N Is the f-ester inherently more reactive? Et Et O Ni–N = 1.912 Å MeO Et Et OMe b Me c H Me Et Et MeO a O H R Et Et N N d O Me OMe N R N Me Co H MeO O 4% e Co N N Me 9 N NH /MeOH 5% d g R 3 H 9% f N N O Me 20% b Et Et Me RT, 5 h 17% mix 38% SM Co–N = 1.974 Å Me H O Et Et R = pyridine R = CN e O f OMe OMe Helv. Chim. Acta. 1985, 68, 1312. 8 N.
Load more

Recommended publications
  • Uneven Distribution of Cobamide Biosynthesis and Dependence in Bacteria Predicted By
    bioRxiv preprint doi: https://doi.org/10.1101/342006; this version posted June 8, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC 4.0 International license. 1 Uneven distribution of cobamide biosynthesis and dependence in bacteria predicted by 2 comparative genomics 3 4 Running title: Cobamide biosynthesis predictions 5 6 Amanda N. Shelton1, Erica C. Seth1, Kenny C. Mok1, Andrew W. Han2, Samantha N. Jackson3,4, 7 David R. Haft3, Michiko E. Taga1* 8 9 1 Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, 10 USA 11 2 Second Genome, Inc., South San Francisco, CA, USA 12 3 J. Craig Venter Institute, Rockville, MD, USA 13 4 Current address: Department of Biological & Environmental Engineering, Cornell University, 14 Ithaca, NY, USA 15 16 * Address correspondence to Michiko E. Taga, [email protected] 17 18 19 -- 20 Abstract 21 22 The vitamin B12 family of cofactors known as cobamides are essential for a variety of microbial 23 metabolisms. We used comparative genomics of 11,000 bacterial species to analyze the extent 1 bioRxiv preprint doi: https://doi.org/10.1101/342006; this version posted June 8, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC 4.0 International license. 24 and distribution of cobamide production and use across bacteria.
    [Show full text]
  • Significance and Implications of Vitamin B-12 Reaction Shema- ETH ZURICH VARIANT: Mechanisms and Insights
    Taylor University Pillars at Taylor University Student Scholarship: Chemistry Chemistry and Biochemistry Fall 2019 Significance and Implications of Vitamin B-12 Reaction Shema- ETH ZURICH VARIANT: Mechanisms and Insights David Joshua Ferguson Follow this and additional works at: https://pillars.taylor.edu/chemistry-student Part of the Analytical Chemistry Commons, Inorganic Chemistry Commons, Organic Chemistry Commons, Other Chemistry Commons, and the Physical Chemistry Commons CHEMISTRY THESIS SIGNIFICANCE AND IMPLICATIONS OF VITAMIN B-12 REACTION SCHEMA- ETH ZURICH VARIANT: MECHANISMS AND INSIGHTS DAVID JOSHUA FERGUSON 2019 2 Table of Contents: Chapter 1 6 Chapter 2 17 Chapter 3 40 Chapter 4 59 Chapter 5 82 Chapter 6 118 Chapter 7 122 Appendix References 3 Chapter 1 A. INTRODUCTION. Vitamin B-12 otherwise known as cyanocobalamin is a compound with synthetic elegance. Considering how it is composed of an aromatic macrocyclic corrin there are key features of this molecule that are observed either in its synthesis of in the biochemical reactions it plays a role in whether they be isomerization reactions or transfer reactions. In this paper the focus for the discussion will be on the history, chemical significance and total synthesis of vitamin B12. Even more so the paper will be concentrated one of the two variants of the vitamin B-12 synthesis, namely the ETH Zurich variant spearheaded by Albert Eschenmoser.Examining the structure as a whole it is observed that a large portion of the vitamin B12 is a corrin structure with a cobalt ion in the center of the macrocyclic part, and that same cobalt ion has cyanide ligands.
    [Show full text]
  • Noncanonical Coproporphyrin-Dependent Bacterial Heme Biosynthesis Pathway That Does Not Use Protoporphyrin
    Noncanonical coproporphyrin-dependent bacterial heme biosynthesis pathway that does not use protoporphyrin Harry A. Daileya,b,c,1, Svetlana Gerdesd, Tamara A. Daileya,b,c, Joseph S. Burcha, and John D. Phillipse aBiomedical and Health Sciences Institute and Departments of bMicrobiology and cBiochemistry and Molecular Biology, University of Georgia, Athens, GA 30602; dMathematics and Computer Science Division, Argonne National Laboratory, Argonne, IL 60439; and eDivision of Hematology, Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132 Edited by J. Clark Lagarias, University of California, Davis, CA, and approved January 12, 2015 (received for review August 25, 2014) It has been generally accepted that biosynthesis of protoheme of a “primitive” pathway in Desulfovibrio vulgaris (13). This path- (heme) uses a common set of core metabolic intermediates that way, named the “alternative heme biosynthesis” path (or ahb), has includes protoporphyrin. Herein, we show that the Actinobacteria now been characterized by Warren and coworkers (15) in sulfate- and Firmicutes (high-GC and low-GC Gram-positive bacteria) are reducing bacteria. In the ahb pathway, siroheme, synthesized unable to synthesize protoporphyrin. Instead, they oxidize copro- from uroporphyrinogen III, can be further metabolized by suc- porphyrinogen to coproporphyrin, insert ferrous iron to make Fe- cessive demethylation and decarboxylation to yield protoheme (14, coproporphyrin (coproheme), and then decarboxylate coproheme 15) (Fig. 1 and Fig. S1). A similar pathway exists for protoheme- to generate protoheme. This pathway is specified by three genes containing archaea (15, 16). named hemY, hemH, and hemQ. The analysis of 982 representa- Current gene annotations suggest that all enzymes for pro- tive prokaryotic genomes is consistent with this pathway being karyotic heme synthetic pathways are now identified.
    [Show full text]
  • 1.1-Billion-Year-Old Porphyrins Establish a Marine Ecosystem Dominated by Bacterial Primary Producers
    1.1-billion-year-old porphyrins establish a marine ecosystem dominated by bacterial primary producers N. Guenelia,1, A. M. McKennab, N. Ohkouchic, C. J. Borehamd, J. Beghine, E. J. Javauxe, and J. J. Brocksa,1 aResearch School of Earth Sciences, Australian National University, Canberra, ACT 2601, Australia; bNational High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310-4005; cDepartment of Biogeochemistry, Japan Agency for Marine–Earth Science and Technology, 237-0061 Kanagawa Prefecture, Yokosuka, Natsushimacho, Japan; dGeoscience Australia, Symonston, ACT 2609, Australia; and eDepartment of Geology, Unité de Recherche Geology, University of Liège, 4000 Liege, Belgium Edited by Andrew H. Knoll, Harvard University, Cambridge, MA, and approved June 8, 2018 (received for review March 6, 2018) The average cell size of marine phytoplankton is critical for the the molecular fossils of biological lipids, can provide comple- flow of energy and nutrients from the base of the food web to mentary information about primary producers. For example, higher trophic levels. Thus, the evolutionary succession of primary hydrocarbon fossils of carotenoid pigments extracted from sed- producers through Earth’s history is important for our understand- imentary rocks have been used to detect phototrophic green ing of the radiation of modern protists ∼800 million years ago and (Chlorobiaceae) and purple sulfur bacteria (PSB) (Chromatia- ∼ the emergence of eumetazoan animals 200 million years later. ceae) in 1,640-My-old marine ecosystems (4, 5), while the con- Currently, it is difficult to establish connections between primary centration of eukaryotic steranes, relative to bacterial hopanes, production and the proliferation of large and complex organisms may provide basic information about the ecological relevance of because the mid-Proterozoic (∼1,800–800 million years ago) rock Precambrian algae (6).
    [Show full text]
  • Synthesis and Spectroscopic Properties of Β-Meso Directly Linked Porphyrin–Corrole Hybrid Compounds
    Synthesis and spectroscopic properties of β-meso directly linked porphyrin–corrole hybrid compounds Baris Temelli* and Hilal Kalkan Full Research Paper Open Access Address: Beilstein J. Org. Chem. 2018, 14, 187–193. Hacettepe University, Department of Chemistry, Beytepe Campus, doi:10.3762/bjoc.14.13 06800, Ankara, Turkey Received: 09 October 2017 Email: Accepted: 05 January 2018 Baris Temelli* - [email protected] Published: 22 January 2018 * Corresponding author Associate Editor: J. Aubé Keywords: © 2018 Temelli and Kalkan; licensee Beilstein-Institut. corrole; hybrid compounds; indium(III) chloride; porphyrin; License and terms: see end of document. porphyrinoids Abstract The preparation of β-meso directly linked porphyrin–corrole hybrids was realized for the first time via an InCl3-catalyzed condensa- tion reaction of 2-formyl-5,10,15,20-tetraphenylporphyrins with meso-substituted dipyrromethanes. Hybrid compounds have been characterized by 1H NMR, 13C NMR, 2D NMR, UV–vis absorption and fluorescence spectroscopy. Introduction Porphyrins and metalloporphyrins play an important role in compounds, corroles, contracted porphyrin analogues [31-33], chemistry, biology, medical and materials sciences because of assumed an important place in porphyrin chemistry due to their their presence in biological compounds such as chlorophyll and small cavities, trianionic characters, high fluorescence quantum heme molecules that have very important functions in the yields and favorable electronic properties. Porphyrin–corrole metabolism of living organisms [1,2]. In recent years, efforts in conjugates have been successfully used as donor–acceptor porphyrin chemistry have been focused on the synthesis of systems in photoinduced charge separation processes. It was multichromophore containing compounds and their potential shown that derivatives of these conjugates could be potentially applications in molecular wires, sensors, nonlinear optical used in photovoltaic applications [21-23].
    [Show full text]
  • Phototrophic Pigment Production with Microalgae
    Phototrophic pigment production with microalgae Kim J. M. Mulders Thesis committee Promotor Prof. Dr R.H. Wijffels Professor of Bioprocess Engineering Wageningen University Co-promotors Dr D.E. Martens Assistant professor, Bioprocess Engineering Group Wageningen University Dr P.P. Lamers Assistant professor, Bioprocess Engineering Group Wageningen University Other members Prof. Dr H. van Amerongen, Wageningen University Prof. Dr M.J.E.C. van der Maarel, University of Groningen Prof. Dr C. Vilchez Lobato, University of Huelva, Spain Dr S. Verseck, BASF Personal Care and Nutrition GmbH, Düsseldorf, Germany This research was conducted under the auspices of the Graduate School VLAG (Advanced studies in Food Technology, Agrobiotechnology, Nutrition and Health Sciences). Phototrophic pigment production with microalgae Kim J. M. Mulders Thesis submitted in fulfilment of the requirement for the degree of doctor at Wageningen University by the authority of the Rector Magnificus Prof. Dr M.J. Kropff, in the presence of the Thesis Committee appointed by the Academic Board to be defended in public on Friday 5 December 2014 at 11 p.m. in the Aula. K. J. M. Mulders Phototrophic pigment production with microalgae, 192 pages. PhD thesis, Wageningen University, Wageningen, NL (2014) With propositions, references and summaries in Dutch and English ISBN 978-94-6257-145-7 Abstract Microalgal pigments are regarded as natural alternatives for food colourants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main focus on secondary carotenoids. Different microalgal groups each possess their own set of primary pigments. Besides, a selected group of green algae (Chlorophytes) accumulate secondary pigments (secondary carotenoids) when exposed to oversaturating light conditions.
    [Show full text]
  • Magnesium-Protoporphyrin Chelatase of Rhodobacter
    Proc. Natl. Acad. Sci. USA Vol. 92, pp. 1941-1944, March 1995 Biochemistry Magnesium-protoporphyrin chelatase of Rhodobacter sphaeroides: Reconstitution of activity by combining the products of the bchH, -I, and -D genes expressed in Escherichia coli (protoporphyrin IX/tetrapyrrole/chlorophyll/bacteriochlorophyll/photosynthesis) LUCIEN C. D. GIBSON*, ROBERT D. WILLOWSt, C. GAMINI KANNANGARAt, DITER VON WETTSTEINt, AND C. NEIL HUNTER* *Krebs Institute for Biomolecular Research and Robert Hill Institute for Photosynthesis, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, United Kingdom; and tCarlsberg Laboratory, Department of Physiology, Gamle Carlsberg Vej 10, DK-2500 Copenhagen Valby, Denmark Contributed by Diter von Wettstein, November 14, 1994 ABSTRACT Magnesium-protoporphyrin chelatase lies at Escherichia coli and demonstrate that the extracts of the E. coli the branch point of the heme and (bacterio)chlorophyll bio- transformants can convert Mg-protoporphyrin IX to Mg- synthetic pathways. In this work, the photosynthetic bacte- protoporphyrin monomethyl ester (20, 21). Apart from posi- rium Rhodobacter sphaeroides has been used as a model system tively identifying bchM as the gene encoding the Mg- for the study of this reaction. The bchH and the bchI and -D protoporphyrin methyltransferase, this work opens up the genes from R. sphaeroides were expressed in Escherichia coli. possibility of extending this approach to other parts of the When cell-free extracts from strains expressing BchH, BchI, pathway. In this paper, we report the expression of the genes and BchD were combined, the mixture was able to catalyze the bchH, -I, and -D from R. sphaeroides in E. coli: extracts from insertion of Mg into protoporphyrin IX in an ATP-dependent these transformants, when combined in vitro, are highly active manner.
    [Show full text]
  • Modifications of Protoporphyrin IX Fluorescence During ALA-Based
    ARTICLE IN PRESS Medical Laser Application 21 (2006) 291–297 www.elsevier.de/mla Modifications of protoporphyrin IX fluorescence during ALA-based photodynamic therapy of endometriosis Karsten Ko¨niga,Ã, Marie-Therese Wyss-Desserichb, Yona Tadirc, Urs Hallerb, Bruce Trombergc, Michael W. Bernsc, P. Wyssb aFraunhofer Institute of Biomedical Technology (IBMT), Ensheimer Straße 48, 66386 St. Ingbert, Germany bDepartment of Obstetrics and Gynecology, Clinic of Gynecology, Frauenklinikstr. 10, University Hospital Zu¨rich, 8091 Zu¨rich, Switzerland cBeckman Laser Institute and Medical Clinic, University of California, 1002 Health Sciences Road Irvine, Irvine, CA 92612, USA Received 20 June 2006; accepted 31 July 2006 Abstract Modifications of the porphyrin fluorescence during photodynamic treatment of ovarian cells, endometrial adenocarcinoma cells and rat uterus after administration of the porphyrin precursor d-aminolevulinic acid and exposure with 630 nm laser radiation have been studied. The intracellular and intratissue fluorescence was excited with 407 nm radiation of a krypton ion laser and detected by spectral microscopic imaging using a modified microscope equipped with a slow-scan cooled camera and a liquid crystal filter. In particular, singlet oxygen induced effects due to photobleaching as well as formation of chlorin-type fluorescent photoproducts were detected at around 500, 630 and 670 nm. The photodynamically induced fluorescence modifications were found to vary between cell types. The major fluorescence peak of PP IX was photobleached 63% by a phototoxic fluence of about 20–40 J/cm2 in cells and within rat endometrium. Higher fluences were required to bleach the fluorescence at around 670 nm due to the formation of fluorescent photoproducts.
    [Show full text]
  • The Function of Pufq in the Regulation of Bacteriochlorophyll Biosynthesis in Rhodobacter Capsulatus
    The Function of PufQ in the Regulation of Bacteriochlorophyll Biosynthesis in Rhodobacter capsulatus Himani Rajeshwar Utkhede B.Sc. Simon Fraser University, 200 1 THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS OF THE DEGREE OF MASTER OF SCIENCE in the Department of Molecular Biology and Biochemistry O Himani R. Utkhede 2004 SIMON FRASER UNIVERSITY March, 2004 All rights reserved. This work may not be reproduced in whole or in part, by photocopy or other means, without permission of the author. Approval I Name: Himani R. Utkhede Degree: Master of Science Title of Thesis: The Function of PufQ in the Regulation of Bacteriochlorophyll Synthesis in Rhodobacter capsulatus. Examining Committee: Dr. W.S. Davidson, Chair Dr. William R. Richards, Senior Supervisor Professor Emeritus, Molecular Biology and Biochemistry Simon Fraser University Dr. Michel Leroux, Supervisor Assistzt Prcfessor, ?v!s!ec.dzr Eic!ca.;- - 2~2L3.icche~isty Simon Fraser University Dr. Erika Plettner, Supervisor Assistant Professor, Chemistry Simon Fraser University Dr. Lynne Quarmby, Internal Examiner Assistant Professor, Biology Simon Fraser University Date Approved: Partial Copyright Licence The author, whose copyright is declared on the title page of this work, has granted to Simon Fraser University the right to lend this thesis, project or extended essay to users of the Simon Fraser University Library, and to make partial or single copies only for such users or in response to a request from the library of any other university, or other educational institution, on its own behalf or for one of its users. The author has further agreed that permission for multiple copying of ths work for scholarly purposes may be granted by either the author or the Dean of Graduate Studies.
    [Show full text]
  • I Topic - Algal Pigments and Algal Classification(ALGAE) Prepared by –Prof.(Dr.)Jainendra Kumar Coordinated By: Prof.(Dr) Shyam Nandan Prasad
    Course- M.Sc. Botany Part -I Paper -I Topic - Algal Pigments and algal Classification(ALGAE) Prepared by –Prof.(Dr.)Jainendra Kumar Coordinated by: Prof.(Dr) Shyam Nandan Prasad The algae were broadly divided by F.F.Fritsch (1935) into eleven classes according to their colour - 1. Chlorophyceae or green algae 2. Xanthophyceae or yellow-green algae 3. Chrysophyceae 4. Bacillariophyceae or golden-brown algae 5. Cryptophyceae 6. Dinophyceae 7. Chloromonadineae 8. Eugleninae 9. Phaeophyceae or brown algae 10. Rhodophyceae or red algae, and 11. Myxophyceae or blue-green algae Normally, classification of algae is based on - 1. Nuclear Organization 2. Nature of Cell Wall Components 3. Pigmentation and Photosynthetic Apparatus The pigment is one of the most important criteria used in differentiation of classes in algae. The pigments in algae can be chlorophylls, carotenoids and biloproteins. These pigments are present in sac like structures called thylakoids. The thylakoids are arranged in stacks in the granum of the chloroplasts. Different groups of algae have different types of pigments and organization of thylakoids in chloroplast. The chlorophylls in algae are chlorophyll a, b, c, d and e types. Chlorophyll a is present in all classes of algae. Chlorophyll b is primary pigment of Chlorophyceae and Euglenineae. Chlorophyll c is found in Phaeophyceae and Cryptophyceae. Chlorophyll d is found in Rhodophyceae. Chlorophyll e is confined to Tribonema of Xanthophyceae. Pigments are chemical compounds which reflect only certain wavelengths of visible light. This makes them appear colourful. More important than their reflection of light is the ability of pigments to absorb certain wavelengths. Since each pigment reacts with only a narrow range of the spectrum, it is important for algae to produce pigments of different colours to capture more of the sun's energy.
    [Show full text]
  • 1 INTRODUCTION Corroles Are Tetrapyrrolic Molecules, Maintaining
    1 Chapter 1 INTRODUCTION Corroles are tetrapyrrolic molecules, maintaining the skeletal structure of corrin, with its three meso carbon positions and one direct pyrrole-pyrrole linkage, and possessing the aromaticity of porphyrins (see figure 1.1). First reported by Johnson and Kay in 1965[1], corroles were the end product of a many step synthetic scheme, finally being formed by the photocyclization of a,c-biladienes. While this last step was simple, with 20-60% yields, the route to a,c-biladienes was far from easy. Indeed, the overall reaction from readily available starting materials to corrole was a multi-step synthesis, with poor yields in many of the reactions. Thus, while corroles have been known for more than 40 years, research in the field was slow to progress. It wasn’t until the discovery of new synthetic methods for corroles developed in 1999 by different groups working independently that research in this area really started to expand[2]. This is not to say, however, that the field of corrole research was non-existent prior to the development of the new methodologies. While it was slow growing after the initial publication, it was far from stagnant, and many of the interesting properties of corroles were investigated by different groups. Among these properties is their ability to stabilize unusually high formal oxidation states of metal ions, such as iron(IV), cobalt(IV), and cobalt(V)[3, 4]. In fact, one particular corrole available through a method developed by Zeev 2 N N H N N H H N N N N a b N N H H H N N c Figure 1.1.
    [Show full text]
  • Luminescence Features of Neodymium(III) Compounds with Various Tetrapyrrole Macrocycles Люминесцентные Свойс
    Porphyrins Paper Порфирины Статья DOI: 10.6060/mhc170621r Luminescence Features of Neodymium(III) Compounds with Various Tetrapyrrole Macrocycles Nikolay N. Semenishyn,a Sergii S. Smola,a Natalya V. Rusakova,a@ Gerbert L. Kamalov,a Yulia G. Gorbunova,b,c and Aslan Yu. Tsivadzeb,c aA.V. Bogatsky Physico-Chemical Institute, 65080 Odessa, Ukraine bA.N. Frumkin Institute of Physical Chemistry and Electrochemistry of Russian Academy of Sciences, 119071 Moscow, Russia cN.S. Kurnakov Institute of General and Inorganic Chemistry of Russian Academy of Sciences, 119991 Moscow, Russia @Corresponding author E-mail: [email protected] We considered the changes in the luminescent properties in the series of neodymium(III) complexes of various coordination types with different tetrapyrrole macrocycles (porphyrins, phthalocyanines and corroles): mono- nuclear complexes (metal-ligand ratio 1:1), sandwich type complexes (metal-ligand ratio 1:2 or 2:3), peripheral binding (on the basis of ditopic tetrapyrrole, metal-ligand ratio 1:1). 4f-Luminescence in the near infrared region is observed in all studied Nd-complexes as a result of intramolecular transfer of excitation energy. Each kind of com- plexes has its unique features, which are discussed. The peripheral complexes are dual-emissive: they display both neodymium(III) 4f-emission and molecular fluorescence. The values of quantum yield of molecular fluorescence as well as 4f-luminescence are estimated. It was found that binding type plays a key role in excited state relaxation pathways in the molecule. Corroles have unusual behaviour in terms of Nd sensitization. Keywords: Tetrapyrroles, luminescence, neodymium, porphyrin, phthalocyanine, corrole. Люминесцентные свойства соединений неодима(III) с различными тетрапиррольными макроциклами Н.
    [Show full text]