2.3 Cyclic Alkanes
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Cyclopropane Anaesthesia by JOHN BOYD, M.D., D.A
Cyclopropane Anaesthesia By JOHN BOYD, M.D., D.A. TLHIS paper is based on my experience of one thousand cases of cyclopropane anaesthesia personally conducted by me since October, 1938, both in hospital and in private. But before discussing these it might be convenient for me to mention here something about the drug itself. HISTORY. Cyclopropane was first isolated in Germany in 1882 by Freund, who also demonstrated its chemical structure, C3H6. He did not, however, describe its anaesthetic properties. Following its discovery it seems to have been forgotten until 1928, when Henderson and Lucas of Toronto, in investigating contaminants of propylene, another anesthetic with undesirable side-effects, and itself'an isomer of cyclopropane, found that the supposed cause of the cardiac disturbances was in reality a better and less toxic anaesthetic. They demonstrated its anaesthetic properties first on animals, and then, before releasing it to the medical profession for clinical trial, they anaesthetised each other, and determined the quantities necessary for administration to man. In 1933 the first clinical trials of cyclopropane were made by Waters and his associates of the University of Wisconsin. In October of that year Waters presented a preliminary report on its anaesthetic properties in man,1 confirming the findings of Henderson and Lucas. Rowbotham introduced it to England first in 1935, and since then its use has spread rapidly throughout the country. PREPARATION. Cyclopropane is prepared commercially by the reduction of trimethylene bromide in the presence of metallic zinc in ethyl alcohol. It is also made commercially from propane in natural gas by progressive thermal chlorination. -
Unnamed Document
Mutations M287L and Q266I in the Glycine Receptor ␣1 Subunit Change Sensitivity to Volatile Anesthetics in Oocytes and Neurons, but Not the Minimal Alveolar Concentration in Knockin Mice Cecilia M. Borghese, Ph.D.,* Wei Xiong, Ph.D.,† S. Irene Oh, B.S.,‡ Angel Ho, B.S.,§ S. John Mihic, Ph.D.,ʈ Li Zhang, M.D.,# David M. Lovinger, Ph.D.,** Gregg E. Homanics, Ph.D.,†† Edmond I. Eger 2nd, M.D.,‡‡ R. Adron Harris, Ph.D.§§ ABSTRACT What We Already Know about This Topic • Inhibitory spinal glycine receptor function is enhanced by vol- Background: Volatile anesthetics (VAs) alter the function of atile anesthetics, making this a leading candidate for their key central nervous system proteins but it is not clear which, immobilizing effect if any, of these targets mediates the immobility produced by • Point mutations in the ␣1 subunit of glycine receptors have been identified that increase or decrease receptor potentiation VAs in the face of noxious stimulation. A leading candidate is by volatile anesthetics the glycine receptor, a ligand-gated ion channel important for spinal physiology. VAs variously enhance such function, and blockade of spinal glycine receptors with strychnine af- fects the minimal alveolar concentration (an anesthetic What This Article Tells Us That Is New EC50) in proportion to the degree of enhancement. • Mice harboring specific mutations in their glycine receptors Methods: We produced single amino acid mutations into that increased or decreased potentiation by volatile anesthetic in vitro did not have significantly altered changes in anesthetic the glycine receptor ␣1 subunit that increased (M287L, third potency in vivo transmembrane region) or decreased (Q266I, second trans- • These findings indicate that this glycine receptor does not me- membrane region) sensitivity to isoflurane in recombinant diate anesthetic immobility, and that other targets must be receptors, and introduced such receptors into mice. -
Cyclobutane Derivatives in Drug Discovery
Cyclobutane Derivatives in Drug Discovery Overview Key Points Unlike larger and conformationally flexible cycloalkanes, Cyclobutane adopts a rigid cyclobutane and cyclopropane have rigid conformations. Due to the ring strain, cyclobutane adopts a rigid puckered puckered conformation Offer ing advantages on (~30°) conformation. This unique architecture bestowed potency, selectivity and certain cyclobutane-containing drugs with unique pharmacokinetic (PK) properties. When applied appropriately, cyclobutyl profile. scaffolds may offer advantages on potency, selectivity and pharmacokinetic (PK) profile. Bridging Molecules for Innovative Medicines 1 PharmaBlock designs and Cyclobutane-containing Drugs synthesizes over 1846 At least four cyclobutane-containing drugs are currently on the market. cyclobutanes, and 497 Chemotherapy carboplatin (Paraplatin, 1) for treating ovarian cancer was cyclobutane products are prepared to lower the strong nephrotoxicity associated with cisplatin. By in stock. CLICK HERE to replacing cisplatin’s two chlorine atoms with cyclobutane-1,1-dicarboxylic find detailed product acid, carboplatin (1) has a much lower nephrotoxicity than cisplatin. On information on webpage. the other hand, Schering-Plough/Merck’s hepatitis C virus (HCV) NS3/4A protease inhibitor boceprevir (Victrelis, 2) also contains a cyclobutane group in its P1 region. It is 3- and 19-fold more potent than the 1 corresponding cyclopropyl and cyclopentyl analogues, respectively. Androgen receptor (AR) antagonist apalutamide (Erleada, 4) for treating castration-resistant prostate cancer (CRPC) has a spirocyclic cyclobutane scaffold. It is in the same series as enzalutamide (Xtandi, 3) discovered by Jung’s group at UCLA in the 2000s. The cyclobutyl- (4) and cyclopentyl- derivative have activities comparable to the dimethyl analogue although the corresponding six-, seven-, and eight-membered rings are slightly less 2 active. -
Euthanasia of Experimental Animals
EUTHANASIA OF EXPERIMENTAL ANIMALS • *• • • • • • • *•* EUROPEAN 1COMMISSIO N This document has been prepared for use within the Commission. It does not necessarily represent the Commission's official position. A great deal of additional information on the European Union is available on the Internet. It can be accessed through the Europa server (http://europa.eu.int) Cataloguing data can be found at the end of this publication Luxembourg: Office for Official Publications of the European Communities, 1997 ISBN 92-827-9694-9 © European Communities, 1997 Reproduction is authorized, except for commercial purposes, provided the source is acknowledged Printed in Belgium European Commission EUTHANASIA OF EXPERIMENTAL ANIMALS Document EUTHANASIA OF EXPERIMENTAL ANIMALS Report prepared for the European Commission by Mrs Bryony Close Dr Keith Banister Dr Vera Baumans Dr Eva-Maria Bernoth Dr Niall Bromage Dr John Bunyan Professor Dr Wolff Erhardt Professor Paul Flecknell Dr Neville Gregory Professor Dr Hansjoachim Hackbarth Professor David Morton Mr Clifford Warwick EUTHANASIA OF EXPERIMENTAL ANIMALS CONTENTS Page Preface 1 Acknowledgements 2 1. Introduction 3 1.1 Objectives of euthanasia 3 1.2 Definition of terms 3 1.3 Signs of pain and distress 4 1.4 Recognition and confirmation of death 5 1.5 Personnel and training 5 1.6 Handling and restraint 6 1.7 Equipment 6 1.8 Carcass and waste disposal 6 2. General comments on methods of euthanasia 7 2.1 Acceptable methods of euthanasia 7 2.2 Methods acceptable for unconscious animals 15 2.3 Methods that are not acceptable for euthanasia 16 3. Methods of euthanasia for each species group 21 3.1 Fish 21 3.2 Amphibians 27 3.3 Reptiles 31 3.4 Birds 35 3.5 Rodents 41 3.6 Rabbits 47 3.7 Carnivores - dogs, cats, ferrets 53 3.8 Large mammals - pigs, sheep, goats, cattle, horses 57 3.9 Non-human primates 61 3.10 Other animals not commonly used for experiments 62 4. -
Recent Advances in the Total Synthesis of Cyclobutane-Containing Natural Products Cite This: Org
Volume 7 | Number 1 | 7 January 2020 ORGANIC CHEMISTRY FRONTIERS rsc.li/frontiers-organic ORGANIC CHEMISTRY FRONTIERS View Article Online REVIEW View Journal | View Issue Recent advances in the total synthesis of cyclobutane-containing natural products Cite this: Org. Chem. Front., 2020, 7, 136 Jinshan Li,†a Kai Gao, †a Ming Bianb and Hanfeng Ding *a,c Complex natural products bearing strained cyclobutane subunits, including terpenoids, alkaloids and steroids, not only display fascinating architectures, but also show potent biological activities. Due to their unique structures as critical core skeletons in these molecules, a variety of new strategies for the con- Received 24th September 2019, struction of cyclobutane rings have greatly emerged during the last decade. In this review, we wish to Accepted 11th November 2019 summarize the recent progress in the cyclobutane-containing natural product synthesis with an emphasis DOI: 10.1039/c9qo01178a on disconnection tactics employed to forge the four-membered rings, aiming to provide a complement rsc.li/frontiers-organic to existing reviews. 1. Introduction stereoselectively, poses significant challenges in synthetic chemistry. On the other hand, cyclobutanes readily undergo a In the class of strained carbocycles, cyclobutanes have been number of ring-opening reactions by virtue of their tendency known as intriguing structural motifs for more than one to release inherent strain energies. In some cases, however, century but remained relatively less explored in parallel with striking ring strains can be dramatically reduced by the instal- their homologues.1 Due to the highly strained ring systems (ca. lation of a gem-dialkyl substituent (through the Thorpe–Ingold − 26.7 kcal mol 1), construction of cyclobutane rings, especially effect),2 a carbonyl group, a heteroatom, or other functional- ities (Fig. -
Pharmacology – Inhalant Anesthetics
Pharmacology- Inhalant Anesthetics Lyon Lee DVM PhD DACVA Introduction • Maintenance of general anesthesia is primarily carried out using inhalation anesthetics, although intravenous anesthetics may be used for short procedures. • Inhalation anesthetics provide quicker changes of anesthetic depth than injectable anesthetics, and reversal of central nervous depression is more readily achieved, explaining for its popularity in prolonged anesthesia (less risk of overdosing, less accumulation and quicker recovery) (see table 1) Table 1. Comparison of inhalant and injectable anesthetics Inhalant Technique Injectable Technique Expensive Equipment Cheap (needles, syringes) Patent Airway and high O2 Not necessarily Better control of anesthetic depth Once given, suffer the consequences Ease of elimination (ventilation) Only through metabolism & Excretion Pollution No • Commonly administered inhalant anesthetics include volatile liquids such as isoflurane, halothane, sevoflurane and desflurane, and inorganic gas, nitrous oxide (N2O). Except N2O, these volatile anesthetics are chemically ‘halogenated hydrocarbons’ and all are closely related. • Physical characteristics of volatile anesthetics govern their clinical effects and practicality associated with their use. Table 2. Physical characteristics of some volatile anesthetic agents. (MAC is for man) Name partition coefficient. boiling point MAC % blood /gas oil/gas (deg=C) Nitrous oxide 0.47 1.4 -89 105 Cyclopropane 0.55 11.5 -34 9.2 Halothane 2.4 220 50.2 0.75 Methoxyflurane 11.0 950 104.7 0.2 Enflurane 1.9 98 56.5 1.68 Isoflurane 1.4 97 48.5 1.15 Sevoflurane 0.6 53 58.5 2.5 Desflurane 0.42 18.7 25 5.72 Diethyl ether 12 65 34.6 1.92 Chloroform 8 400 61.2 0.77 Trichloroethylene 9 714 86.7 0.23 • The volatile anesthetics are administered as vapors after their evaporization in devices known as vaporizers. -
Annex XV Report
Annex XV report PROPOSAL FOR IDENTIFICATION OF A SUBSTANCE OF VERY HIGH CONCERN ON THE BASIS OF THE CRITERIA SET OUT IN REACH ARTICLE 57 Substance Name(s): 1,6,7,8,9,14,15,16,17,17,18,18- Dodecachloropentacyclo[12.2.1.16,9.02,13.05,10]octadeca-7,15-diene (“Dechlorane Plus”TM) [covering any of its individual anti- and syn-isomers or any combination thereof] EC Number(s): 236-948-9; -; - CAS Number(s): 13560-89-9; 135821-74-8; 135821-03-3 Submitted by: United Kingdom Date: 29 August 2017 ANNEX XV – IDENTIFICATION OF DECHLORANE PLUS AS SVHC CONTENTS PROPOSAL FOR IDENTIFICATION OF A SUBSTANCE OF VERY HIGH CONCERN ON THE BASIS OF THE CRITERIA SET OUT IN REACH ARTICLE 57..........................................................................................IV PART I ...............................................................................................................................................1 JUSTIFICATION ..................................................................................................................................1 1. IDENTITY OF THE SUBSTANCE AND PHYSICAL AND CHEMICAL PROPERTIES ...................................2 1.1 Name and other identifiers of the substance................................................................................2 1.2 Composition of the substance ........................................................................................................2 1.3 Identity and composition of degradation products/metabolites relevant for the SVHC assessment ....................................................................................................................................3 -
SAFETY DATA SHEET Cyclopentane
SAFETY DATA SHEET Cyclopentane Section 1. Identification GHS product identifier : Cyclopentane Chemical name : cyclopentane Other means of : cyclopentane (dot); pentamethylene identification Product use : Synthetic/Analytical chemistry. Synonym : cyclopentane (dot); pentamethylene SDS # : 001124 Supplier's details : Airgas USA, LLC and its affiliates 259 North Radnor-Chester Road Suite 100 Radnor, PA 19087-5283 1-610-687-5253 24-hour telephone : 1-866-734-3438 Section 2. Hazards identification OSHA/HCS status : This material is considered hazardous by the OSHA Hazard Communication Standard (29 CFR 1910.1200). Classification of the : FLAMMABLE LIQUIDS - Category 2 substance or mixture AQUATIC HAZARD (ACUTE) - Category 3 AQUATIC HAZARD (LONG-TERM) - Category 3 GHS label elements Hazard pictograms : Signal word : Danger Hazard statements : Highly flammable liquid and vapor. May form explosive mixtures in Air. Harmful to aquatic life with long lasting effects. Precautionary statements General : Read label before use. Keep out of reach of children. If medical advice is needed, have product container or label at hand. Prevention : Wear protective gloves. Wear eye or face protection. Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking. Use explosion- proof electrical, ventilating, lighting and all material-handling equipment. Use only non- sparking tools. Take precautionary measures against static discharge. Keep container tightly closed. Avoid release to the environment. Response : IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower. Storage : Store in a well-ventilated place. Keep cool. Disposal : Dispose of contents and container in accordance with all local, regional, national and international regulations. Hazards not otherwise : None known. -
Classification of Chemicals
Classification of Chemicals Flame & Detonation Arrester Specifications PROTECTOSEAL ® The Protectoseal Company recommends that the National Butadiene would qualify as a Group D material. In each of Electric Code (NEC) Article 500, rankings of various chemi - these cases, the chemicals were primarly listed in a higher cals be used, whenever possible, to determine the suitability category (Group B), because of relatively high pressure read - of a detonation arrester for use with a particular chemical. ings noted in one phase of the standard test procedure con - When no NEC rating of the particular chemical is available, ducted by Underwriters Laboratories. These pressures were the International Electrotechnical Commission (IEC) classifica - of concern when categorizing the chemicals because these tion (Groups IIA, IIB and IIC) is recommended as a secondary NEC groupings are also used as standard indicators for the source of information for determining the suitability of an ar - design strength requirements of electrical boxes, apparatus, rester for its intended service. In general, the IEC Group IIA is etc. that must withstand the pressures generated by an igni - equivalent to the NEC Group D; the IEC Group IIB is equiva - tion within the container. It should be noted that, in each of lent to the NEC Group C; and the IEC Group IIC includes these cases, the test pressures recorded were significantly chemicals in the NEC Groups A and B. In the event of a dis - lower than those commonly encountered when testing a deto - crepancy between the NEC and the IEC ratings, Protectoseal nation arrester for its ability to withstand stable and over - recommends that the NEC groups be referenced. -
MSDS Cyclopentane (1).Pdf
MATERIAL SAFETY DATA SHEET (MSDS) CYCLOPENTANE 1. CHEMICAL PRODUCT AND COMPANY IDENTIFICATION SUBSTANCE OR PREPATION TRADE NAME Cyclopentane CHEMICAL CLASSIFICATION Cycloparaffin, Naphthene COMPANY/ UNDERTAKING NAME AND Haldia Petrochemicals Limited, ADDRESS PO Box No 12, Haldia Plant PO Durgachak, Dist Midnapore West Bengal, India PIN 721 602 TELEPHONE 091-3224-274384 / 274400 EMERGENCY TELEPHONE NUMBER 091-3224-275916 2. COMPOSTION AND INFORMATION ON INGREDIENTS CHEMICAL CHEMICLAL CONTENT CAS EXPOSURE LIMITS IN AIR NAME FORMULA NUMBER (ppm) ACGIH ACGIH IDLH TLV- TLV- TWA STEL Cyclopentane C5H10 98.20 wt% 287-92-3 600 NA NA 2,2 Dimethyl (CH3)3CCH2CH3 0.28 wt% 75-83-2 500 1000 NA butane n- pentane n- C5H12 1.47 wt% 109-66-0 600 750 NA i- Pentane i- C5H12 0.05 wt% 78-78-4 600 750 NA Total Sulpher S < 1.0 wt. ppm 7704-34-9 NA NA NA 3. HAZARD CLASSIFICATION Highly flammable liquid and vapour. Vapour EMERGENCY OVERVIEW may cause flash fire. Harmful or Fatal is enter lungs and cause damage POTENTIAL HEALTH HAZARDS EYE SKIN INHALATION INGESTION OTHERS ACUTE To cause Not expected Dizziness, Abdominal prolonged or to be harmful headache, pain, significant to internal nausea, diarrhoea, eye irritation organs if Unconsciousness, dizziness, absorbed weakness nausea, sore through the throat skin. CHRONIC Repeated or prolonged contact with skin may cause dermatitis NFPA HAZARD HEALTH FLAMMABILITY REACTIVITY SPECIAL SIGNALS 2 3 0 - HAZCHEM CODE 3YE GHS-Classification Flammable liquids Category 2 Aspiration hazard Category 1 Chronic aquatic toxicity, Category 3 Acute aquatic toxicity, Category 3 Target Organ Systemic Toxicant - Single exposure, Category 3, Inhalation, Central nervous system Document Compiled By Approved By Issue No Rev. -
Cycloalkanes, Cycloalkenes, and Cycloalkynes
CYCLOALKANES, CYCLOALKENES, AND CYCLOALKYNES any important hydrocarbons, known as cycloalkanes, contain rings of carbon atoms linked together by single bonds. The simple cycloalkanes of formula (CH,), make up a particularly important homologous series in which the chemical properties change in a much more dramatic way with increasing n than do those of the acyclic hydrocarbons CH,(CH,),,-,H. The cyclo- alkanes with small rings (n = 3-6) are of special interest in exhibiting chemical properties intermediate between those of alkanes and alkenes. In this chapter we will show how this behavior can be explained in terms of angle strain and steric hindrance, concepts that have been introduced previously and will be used with increasing frequency as we proceed further. We also discuss the conformations of cycloalkanes, especially cyclo- hexane, in detail because of their importance to the chemistry of many kinds of naturally occurring organic compounds. Some attention also will be paid to polycyclic compounds, substances with more than one ring, and to cyclo- alkenes and cycloalkynes. 12-1 NOMENCLATURE AND PHYSICAL PROPERTIES OF CYCLOALKANES The IUPAC system for naming cycloalkanes and cycloalkenes was presented in some detail in Sections 3-2 and 3-3, and you may wish to review that ma- terial before proceeding further. Additional procedures are required for naming 446 12 Cycloalkanes, Cycloalkenes, and Cycloalkynes Table 12-1 Physical Properties of Alkanes and Cycloalkanes Density, Compounds Bp, "C Mp, "C diO,g ml-' propane cyclopropane butane cyclobutane pentane cyclopentane hexane cyclohexane heptane cycloheptane octane cyclooctane nonane cyclononane "At -40". bUnder pressure. polycyclic compounds, which have rings with common carbons, and these will be discussed later in this chapter. -
Cyclopentane Cyp
CYCLOPENTANE CYP CAUTIONARY RESPONSE INFORMATION 4. FIRE HAZARDS 7. SHIPPING INFORMATION 4.1 Flash Point: 7.1 Grades of Purity: Commercial; 60% (remainder Common Synonyms Watery liquid Colorless Mild, sweet odor < 20°F C.C. consists of hydrocarbons of similar boiling Pentamethylene 4.2 Flammable Limits in Air: (approx.) 1.1%- point); Research: 99+% 8.7% 7.2 Storage Temperature: Ambient Floats on water. Flammable, irritating vapor is produced. 4.3 Fire Extinguishing Agents: Dry 7.3 Inert Atmosphere: No requirement chemical, foam, carbon dioxide Keep people away. 7.4 Venting: Pressure-vacuum Avoid inhalation. 4.4 Fire Extinguishing Agents Not to Be Shut off ingition sources. Call fire department. Used: Water may be ineffective. 7.5 IMO Pollution Category: (C) Evacuate area in case of large discharge. 4.5 Special Hazards of Combustion 7.6 Ship Type: 3 Notify local health and pollution control agencies. Products: Not pertinent 7.7 Barge Hull Type: Currently not available Protect water intakes. 4.6 Behavior in Fire: Containers may explode. FLAMMABLE. 8. HAZARD CLASSIFICATIONS Fire 4.7 Auto Ignition Temperature: 682°F Containers may explode in fire. 8.1 49 CFR Category: Flammable liquid Flashback along vapor trail may occur. 4.8 Electrical Hazards: Not pertinent 8.2 49 CFR Class: 3 Vapor may explode if ignited in an enclosed area. 4.9 Burning Rate: 7.9 mm/min. 8.3 49 CFR Package Group: II Extinguish with dry chemicals, foam or carbon dioxide. 4.10 Adiabatic Flame Temperature: Currently Water may be ineffective on fire. not available 8.4 Marine Pollutant: No Cool exposed containers with water.