DOCSLIB.ORG

Estimation of Melting Points of Organic Compounds

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Estimation of Melting Points of Organic Compounds Estimation of Melting Points of Organic Compounds Item Type text; Electronic Dissertation Authors Jain, Akash Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 23/09/2021 18:32:56 Link to Item http://hdl.handle.net/10150/193516 ESTIMATION OF MELTING POINTS OF ORGANIC COMPOUNDS By Akash Jain Copyright © Akash Jain 2005 A Dissertation Submitted to the Faculty of the DEPARTMENT OF PHARMACEUTICAL SCIENCES In Partial Fulfillment of the Requirements For the Degree of DOCTORAL OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 2005 2 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE As members of the Dissertation Committee, we certify that we have read the dissertation prepared by Akash Jain entitled Estimation of Melting Points of Organic Compounds and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy _______________________________________________________________________ Date: (10-17-05) Samuel H. Yalkowsky, Ph.D. _______________________________________________________________________ Date: (10-17-05) Michael Mayersohn, Ph.D. _______________________________________________________________________ Date: (10-17-05) Paul B. Myrdal, Ph.D. _______________________________________________________________________ Date: (10-17-05) Srini Raghavan, Ph.D. _______________________________________________________________________ Date: ( ) Final approval and acceptance of this dissertation is contingent upon the candidate’s submission of the final copies of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. ________________________________________________ Date: (10-17-05) Dissertation Director: Samuel H. Yalkowsky, Ph.D. 3 STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited at the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgement of the source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the copyright holder. AKASH JAIN 4 ACKNOWLEDGEMENTS I would like to express my gratitude to my advisor, Dr Samuel Yalkowsky, for providing me the opportunity and financial support to earn my doctoral degree in Pharmaceutical Sciences. I sincerely thank him for his continued guidance, encouragement and mentorship over the years I spent at the University of Arizona. I will cherish his scientific values, virtues and philosophies for life. I would like to thank my major committee members, Dr Michael Mayersohn and Dr Paul Myrdal, for their guidance and comments in not only preparing this dissertation but for my entire period of education at the University of Arizona. I would also like to express my gratitude to my minor committee members, Dr Srini Ragahvan and Dr Neal Armstrong, for dedicating their time to serve on my committee. I would like to thank my past and present colleagues at the University of Arizona for being there for me whenever I needed them. I will inherit all the good times we have had working together and I am pleased to have made some friends for life. I would like to thank my professors back in India, especially Dr T.R.Saini and Dr. S.C. Chaturvedi, for encouraging me to pursue a doctoral degree in Pharmaceutical Sciences. At last, I would like to thank my family: my parents and sister for their love and inspiration, my fiancée Bhumika for all her love and patience and her family for their care and support. 5 DEDICATION To my parents and Bhumika 6 TABLE OF CONTENTS LIST OF FIGURES……………………………………………………………………….9 LIST OF TABLES……………………………………………………………………….10 ABSTRACT……………………………………………………………………………...11 CHAPTER 1: INTRODUCTION………………………………………………………..12 CHAPTER 2: ENTHALPY OF MELTING……………………………………………..19 INTRODUCTION…………………………………………………………………….19 DATA…………………………………………………………………………………21 MODEL……………………………………………………………………………….22 Group Definition…………………………………………………………………....22 Group Environment………………………………………………………………....23 Proximity Factors…………………………………………………………………...24 METHODS……………………………………………………………………………26 RESULTS AND DISCUSSION………………………………………………………26 SUMMARY…………………………………………………………………………...36 CHAPTER 3: ENTROPY OF MELTING……………………………………………….38 INTRODUCTION…………………………………………………………………….38 DATA………………………………………………………………………………....40 METHODS……………………………..……………………………………………..40 Molecular Rotational Symmetry Number…………………………………………..40 Molecular Flexibility Number……………………………………………………...42 7 TABLE OF CONTENTS – Continued RESULTS AND DISCUSSION………………………………………………………44 SUMMARY….………………………………………………………………………..48 CHAPTER 4: MELTING POINTS………………………………………………………49 INTRODUCTION……………………………………………………………………..49 DATA………………………………………………………………………………… 52 METHODS………………………………………………………………………….... 52 RESULTS AND DISCUSSION……………………………………………………… 53 SUMMARY…………………………………………………………………………... 60 CHAPTER 5: COMPARISON OF TWO METHODS FOR PREDICTING MELTING POINTS…………………………………………………………………………………..61 INTRODUCTION……………………………………………………………………..61 DATA………………………………………………………………………………….61 METHODS………………………………………………………………………….....61 RESULTS AND DISCUSSION……………………………………………………… 63 SUMMARY…………………………………………………………………………... 66 APPENDIX A. Examples of predicting enthalpy of melting (KHm), entropy of melting (KSm) and melting point (Tm) using the developed model………………………………. 67 APPENDIX B. Experimental and predicted enthalpy of melting (KHm) for 1663 organic compounds……………………………………………………………………………….69 8 TABLE OF CONTENTS - Continued APPENDIX C. Rotational symmetry number (L), Flexibility count (Ф), experimental entropy of melting and predicted entropy of melting (KSm) for 1663 organic Compounds……………………………………………………………………………...101 APPENDIX D. Experimental and predicted Melting Points (Tm) for 2230 organic compounds………………………………………………………………………………135 REFERENCES………………………………………………………………………….178 9 LIST OF FIGURES Figure 1.1: UPPER (Unified Physical Property Estimation Relationships) Scheme…... .12 Figure 2.1(a): Sulfonylureas……………………………………………………………...23 Figure 2.1(b): Barbiturates………………………………………………………………. 23 Figure2.2: Molecular environment descriptors in the fragmentation scheme……………24 Figure2.3: Intramolecular hydrogen bonding patterns…………………………………... 25 Figure 2.4: The distribution of errors in predicting enthalpy of melting………………... 35 Figure 3.1: Symmetry numbers for several molecules………………………………….. 42 Figure 3.2: The distribution of errors in predicting entropy of melting………………….45 Figure 3.3: Error distribution as a function of the logarithm of the rotational symmetry number (L)…………………………………………………………………….46 Figure 3.4: Error distribution as a function of the logarithm of the molecular flexibility number (N)……………………………………………………………………. 46 Figure 4.1: Observed versus predicted melting points for 2230 organic compounds……53 Figure 4.2: Error distribution in melting point prediction using the proposed model…... 54 Figure 4.3: Predicted versus observed melting points for 152 drugs (including steroids) in the database………………............................................................56 Figure 4.4: Predicted versus observed melting points for 149 environmental compounds included in the database……………………………………………………..57 Figure 4.5: Proximity factors for intramolecular hydrogen bonding and geminal fluorine atoms in Dinitramine…………………………………………………………… 58 Figure 4.6: Experimental melting points of n-alkanes (C2-C190)……………………….59 Figure 5.1: Observed versus predicted melting points (using UPPER) for 2230 compounds……………………………………………………………………...63 Figure 5.2: Observed versus predicted melting points (using MPBPWIN) for 2230 compounds………………………………………………………………………………. 64 Figure 5.3: AAE in melting point prediction of symmetrical molecules using the two models…………………………………………………………………………... 65 Figure 5.4: AAE in melting point predictions of flexible molecules using the two models…………………………………………………………………………... 65 10 LIST OF TABLES Table 1.1: Experimental melting points (°C) of some homologous series……………….14 Table 1.2: Experimental melting points for some octanes………………………………. 15 Table 1.3: Experimental melting points for isomeric arenes……………………………. 15 Table 1.4: Experimental melting points (°C) for some disubstituted benzenes…………. 15 Table 2.1: A list of molecular fragments and proximity factors along with their enthalpy contribution values…………………………………………………………….. 27 Table 2.2: Frequency distribution of the average absolute errors in enthalpy of melting prediction……………………………………………………………………...... 36 Table 3.1: Examples of some molecular flexibility numbers…………………………….44 Table 3.2: Average absolute errors in entropy of melting prediction at different flexibility count (Ф)……………………………………………………………………... 47 Table 3.3: Frequency distribution of the average absolute errors in entropy of melting prediction……………………………………………………………………….. 47 Table 4.1: Average Absolute Errors in general melting point estimation methods……... 51 Table 4.2: Frequency distribution of the average absolute errors in melting point
Load more

Recommended publications
  • US 2014/0116112 A1 HUMPHREY Et Al
    US 201401 16112A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2014/0116112 A1 HUMPHREY et al. (43) Pub. Date: May 1, 2014 (54) METHODS FOR DETERMINING THE Publication Classification PRESENCE OR ABSENCE OF CONTAMINANTS IN A SAMPLE (51) Int. Cl. GOIN30/72 (2006.01) (71) Applicant: K & D LABORATORIES, INC., Lake (52) U.S. Cl. Oswego, OR (US) CPC .................................. G0IN30/7206 (2013.01) USPC ......................................................... T3/23.37 (72) Inventors: David Kent HUMPHREY, Reno, NV (US); Nicholas Joseph GEISE, Portland, OR (US) (57) ABSTRACT (73) Assignee: K & D LABORATORIES, INC., Lake Oswego, OR (US) Methods are provided for rapidly determining the presence or absence of large numbers of contaminants in a test sample, (21) Appl. No.: 13/830,388 Such as a raw material intended for use in the preparation of a nutraceutical. The disclosed methods employ gas chromatog (22) Filed: Mar 14, 2013 raphy-mass spectrometry techniques together with the spe cific use of software in combination with a database to ana Related U.S. Application Data lyze data collected after ionization of the sample and (60) Provisional application No. 61/718,607, filed on Oct. determine the presence or absence of the contaminants in the 25, 2012. sample. US 2014/01161 12 A1 May 1, 2014 METHODS FOR DETERMINING THE 0007. In one embodiment, methods for detecting the pres PRESENCE OR ABSENCE OF ence or absence of a plurality of contaminants in a sample are CONTAMINANTS IN A SAMPLE provided, such methods comprising: (a) extracting the sample with a water-miscible solvent in the presence of a high con REFERENCE TO RELATED APPLICATIONS centration of salts to provide a sample extract; (b) shaking and centrifuging the sample extract to provide a Supernatant; (c) 0001.
    [Show full text]
  • Factors Influencing Pesticide Resistance in Psylla Pyricola Foerster and Susceptibility Inits Mirid
    AN ABSTRACT OF THE THESIS OF: Hugo E. van de Baan for the degree ofDoctor of Philosopbv in Entomology presented on September 29, 181. Title: Factors Influencing Pesticide Resistance in Psylla pyricola Foerster and Susceptibility inits Mirid Predator, Deraeocoris brevis Knight. Redacted for Privacy Abstract approved: Factors influencing pesticide susceptibility and resistance were studied in Psylla pyricola Foerster, and its mirid predator, Deraeocoris brevis Knight in the Rogue River Valley, Oregon. Factors studied were at the biochemical, life history, and population ecology levels. Studies on detoxification enzymes showed that glutathione S-transferase and cytochrome P-450 monooxygenase activities were ca. 1.6-fold higherin susceptible R. brevis than in susceptible pear psylla, however, esterase activity was ca. 5-fold lower. Esterase activity was ca. 18-fold higher in resistant pear psylla than in susceptible D. brevis, however, glutathione S-transferase and cytochrome P-450 monooxygenase activities were similar. Esterases seem to be a major factor conferring insecticideresistance in P. Pvricola. Although the detoxification capacities of P. rivricola and D. brevis were quite similar, pear psylla has developed resistance to many insecticides in the Rogue River Valley, whereas D. brevis has remained susceptible. Biochemical factors may be important in determining the potential of resistance development, however, they are less important in determining the rate at which resistance develops. Computer simulation studies showed that life history and ecological factors are probably of greater importancein determining the rate at which resistance develops in P. pvricola and D. brevis. High fecundity and low immigration of susceptible individuals into selected populations appear to be major factors contributing to rapid resistance development in pear psylla compared with D.
    [Show full text]
  • Supplementary Information for “Oligomeric Models for Estimation of Polydimethylsiloxane
    Electronic Supplementary Material (ESI) for Environmental Science: Processes & Impacts. This journal is © The Royal Society of Chemistry 2016 Supplementary Information for “Oligomeric models for estimation of polydimethylsiloxane- water partition ratios with COSMO-RS theory: Impact of the combinatorial term on absolute error” by J. Mark Parnis and Donald Mackay. Contents: 1) The complete set of chemicals, with the published values of log K(PDMS-w), and the abbreviated reference, corresponding to references given in the principle text. 1) The complete set of chemicals, with the published values of log KPDMS-w. Hsieh 2011 CHAO 2014 PCB18 4.91 PCB203 7.09 PCB16 5.12 PCB195 6.89 PCB32 5.12 PCB194 6.79 PCB28,31 5.17 Benzyl alcohol -0.35 PCB33,53 5.18 4-Fluorophenol -0.28 PCB22 5.30 m-Cresol -0.03 PCB52 5.48 Phenethyl alcohol 0.12 PCB47,48 5.49 3-Methylbenzyl alcohol 0.17 PCB44 5.44 3-Chlorophenol 0.31 PCB71 5.49 3,5-Dimethylphenol 0.42 PCB41 5.49 3-Bromophenol 0.46 PCB70 5.79 4-Ethylphenol 0.60 PCB66 5.70 4-Chloroaniline 0.84 PCB95 5.77 Phenyl acetate 0.86 PCB56,60 5.86 Benzonitrile 1.04 PCB101 6.01 Acetophenone 1.04 PCB99 6.17 4-Chloroacetophenone 1.64 PCB83 6.02 Methyl benzoate 1.65 PCB97 6.05 Benzene 1.76 PCB87 6.19 Ethylbenzoate 2.12 PCB85 6.38 Toluene 2.28 PCB110 6.03 4-Chloroanisole 2.37 PCB151 6.31 Chlorobenzene 2.40 PCB135 6.48 Bromobenzene 2.51 PCB149 6.42 o-Xylene 2.69 PCB118 6.23 m-Xylene 2.73 PCB146 6.66 Iodobenzene 2.73 PCB153 6.62 p-Xylene 2.75 PCB105,132 6.40 Ethylbenzene 2.75 PCB179 6.73 Phenol -0.18 PCB141 6.73 Naphthalene 2.83 PCB138 6.61 Cyclopentane 2.85 PCB163 6.56 4-Chlorotoluene 2.87 PCB158 6.83 Methylcyclopentane 3.13 PCB187 6.96 Propylbenzene 3.14 PCB182 6.96 Isopropylbenzene 3.15 PCB183 6.26 1,3,5-Trimethylbenzene 3.16 PCB128 6.61 1-Methyl-4-Ethylbenzene 3.20 PCB185 6.86 Cyclohexane 3.20 PCB174 7.04 1-Methylnaphthalene 3.26 PCB177 7.02 1,2,4-Trimethylbenzene 3.34 PCB171,202 6.78 tert-Butylbenzene 3.34 PCB180 6.89 Biphenyl 3.37 PCB170 6.82 2,3-Dimethylbutane 3.37 PCB201 7.06 2-Methylpentane 3.51 CHAO 2014 Kang et al.
    [Show full text]
  • Catalytic Pyrolysis of Plastic Wastes for the Production of Liquid Fuels for Engines
    Electronic Supplementary Material (ESI) for RSC Advances. This journal is © The Royal Society of Chemistry 2019 Supporting information for: Catalytic pyrolysis of plastic wastes for the production of liquid fuels for engines Supattra Budsaereechaia, Andrew J. Huntb and Yuvarat Ngernyen*a aDepartment of Chemical Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen, 40002, Thailand. E-mail:[email protected] bMaterials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand Fig. S1 The process for pelletization of catalyst PS PS+bentonite PP ) t e PP+bentonite s f f o % ( LDPE e c n a t t LDPE+bentonite s i m s n HDPE a r T HDPE+bentonite Gasohol 91 Diesel 4000 3500 3000 2500 2000 1500 1000 500 Wavenumber (cm-1) Fig. S2 FTIR spectra of oil from pyrolysis of plastic waste type. Table S1 Compounds in oils (%Area) from the pyrolysis of plastic wastes as detected by GCMS analysis PS PP LDPE HDPE Gasohol 91 Diesel Compound NC C Compound NC C Compound NC C Compound NC C 1- 0 0.15 Pentane 1.13 1.29 n-Hexane 0.71 0.73 n-Hexane 0.65 0.64 Butane, 2- Octane : 0.32 Tetradecene methyl- : 2.60 Toluene 7.93 7.56 Cyclohexane 2.28 2.51 1-Hexene 1.05 1.10 1-Hexene 1.15 1.16 Pentane : 1.95 Nonane : 0.83 Ethylbenzen 15.07 11.29 Heptane, 4- 1.81 1.68 Heptane 1.26 1.35 Heptane 1.22 1.23 Butane, 2,2- Decane : 1.34 e methyl- dimethyl- : 0.47 1-Tridecene 0 0.14 2,2-Dimethyl- 0.63 0 1-Heptene 1.37 1.46 1-Heptene 1.32 1.35 Pentane,
    [Show full text]
  • 3745-100-10 Applicable Chemicals and Chemical Categories
    3745-100-10 Applicable chemicals and chemical categories. [Comment: For dates of non-regulatory government publications, publications of recognized organizations and associations, federal rules, and federal statutory provisions referenced in this rule, see the "Incorporation by Reference" section at the end of rule 3745-100-01.] The requirements of this chapter apply to the following chemicals and chemical categories. This rule contains three listings. Paragraph (A) of this rule is an alphabetical order listing of those chemicals that have an associated "Chemical Abstracts Service (CAS)" registry number. Paragraph (B) of this rule contains a CAS registry number order list of the same chemicals listed in paragraph (A) of this rule. Paragraph (C) of this rule contains the chemical categories for which reporting is required. These chemical categories are listed in alphabetical order and do not have CAS registry numbers. (A) Alphabetical listing: -- Chemical Name CAS Number abamectin (avermectin B1) 71751-41-2 acephate (acetylphosphoramidothioic acid o,s-dimethyl ester) 30560-19-1 acetaldehyde 75-07-0 acetamide 60-35-5 acetonitrile 75-05-8 acetophenone 98-86-2 2-acetylaminofluorene 53-96-3 acifluorfen, sodium salt (5- (2-chloro-4- (trifluoromethyl) - phenoxy)-2-nitro-benzoic acid, sodium salt) 62476-59-9 acrolein 107-02-8 acrylamide 79-06-1 acrylic acid 79-10-7 acrylonitrile 107-13-1 alachlor 15972-60-8 aldicarb 116-06-3 aldrin [1,4,5,8-dimethanonaphthalene, 1,2,3,4,10,10-hexachloro- 1,4,4A,5,8,8a-hexahydro- (1 alpha, 4 alpha, 4a beta, 5
    [Show full text]
  • COMBINED LIST of Particularly Hazardous Substances
    COMBINED LIST of Particularly Hazardous Substances revised 2/4/2021 IARC list 1 are Carcinogenic to humans list compiled by Hector Acuna, UCSB IARC list Group 2A Probably carcinogenic to humans IARC list Group 2B Possibly carcinogenic to humans If any of the chemicals listed below are used in your research then complete a Standard Operating Procedure (SOP) for the product as described in the Chemical Hygiene Plan. Prop 65 known to cause cancer or reproductive toxicity Material(s) not on the list does not preclude one from completing an SOP. Other extremely toxic chemicals KNOWN Carcinogens from National Toxicology Program (NTP) or other high hazards will require the development of an SOP. Red= added in 2020 or status change Reasonably Anticipated NTP EPA Haz list COMBINED LIST of Particularly Hazardous Substances CAS Source from where the material is listed. 6,9-Methano-2,4,3-benzodioxathiepin, 6,7,8,9,10,10- hexachloro-1,5,5a,6,9,9a-hexahydro-, 3-oxide Acutely Toxic Methanimidamide, N,N-dimethyl-N'-[2-methyl-4-[[(methylamino)carbonyl]oxy]phenyl]- Acutely Toxic 1-(2-Chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (Methyl-CCNU) Prop 65 KNOWN Carcinogens NTP 1-(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) IARC list Group 2A Reasonably Anticipated NTP 1-(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) (Lomustine) Prop 65 1-(o-Chlorophenyl)thiourea Acutely Toxic 1,1,1,2-Tetrachloroethane IARC list Group 2B 1,1,2,2-Tetrachloroethane Prop 65 IARC list Group 2B 1,1-Dichloro-2,2-bis(p -chloropheny)ethylene (DDE) Prop 65 1,1-Dichloroethane
    [Show full text]
  • The Alcohol Textbook 4Th Edition
    TTHEHE AALCOHOLLCOHOL TEXTBOOKEXTBOOK T TH 44TH EEDITIONDITION A reference for the beverage, fuel and industrial alcohol industries Edited by KA Jacques, TP Lyons and DR Kelsall Foreword iii The Alcohol Textbook 4th Edition A reference for the beverage, fuel and industrial alcohol industries K.A. Jacques, PhD T.P. Lyons, PhD D.R. Kelsall iv T.P. Lyons Nottingham University Press Manor Farm, Main Street, Thrumpton Nottingham, NG11 0AX, United Kingdom NOTTINGHAM Published by Nottingham University Press (2nd Edition) 1995 Third edition published 1999 Fourth edition published 2003 © Alltech Inc 2003 All rights reserved. No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publishers. ISBN 1-897676-13-1 Page layout and design by Nottingham University Press, Nottingham Printed and bound by Bath Press, Bath, England Foreword v Contents Foreword ix T. Pearse Lyons Presient, Alltech Inc., Nicholasville, Kentucky, USA Ethanol industry today 1 Ethanol around the world: rapid growth in policies, technology and production 1 T. Pearse Lyons Alltech Inc., Nicholasville, Kentucky, USA Raw material handling and processing 2 Grain dry milling and cooking procedures: extracting sugars in preparation for fermentation 9 Dave R. Kelsall and T. Pearse Lyons Alltech Inc., Nicholasville, Kentucky, USA 3 Enzymatic conversion of starch to fermentable sugars 23 Ronan F.
    [Show full text]
  • Campro Catalog Stable Isotope
    Introduction & Welcome Dear Valued Customer, We are pleased to present to you our Stable Isotopes Catalog which contains more than three thousand (3000) high quality labeled compounds. You will find new additions that are beneficial for your research. Campro Scientific is proud to work together with Isotec, Inc. for the distribution and marketing of their stable isotopes. We have been working with Isotec for more than twenty years and know that their products meet the highest standard. Campro Scientific was founded in 1981 and we provide services to some of the most prestigious universities, research institutes and laboratories throughout Europe. We are a research-oriented company specialized in supporting the requirements of the scientific community. We are the exclusive distributor of some of the world’s leading producers of research chemicals, radioisotopes, stable isotopes and environmental standards. We understand the requirements of our customers, and work every day to fulfill them. In working with us you are guaranteed to receive: - Excellent customer service - High quality products - Dependable service - Efficient distribution The highly educated staff at Campro’s headquarters and sales office is ready to assist you with your questions and product requirements. Feel free to call us at any time. Sincerely, Dr. Ahmad Rajabi General Manager 180/280 = unlabeled 185/285 = 15N labeled 181/281 = double labeled (13C+15N, 13C+D, 15N+18O etc.) 186/286 = 12C labeled 182/282 = d labeled 187/287 = 17O labeled 183/283 = 13C labeleld 188/288 = 18O labeled 184/284 = 16O labeled, 14N labeled 189/289 = Noble Gases Table of Contents Ordering Information.................................................................................................. page 4 - 5 Packaging Information ..............................................................................................
    [Show full text]
  • Minutes of the IUPAC Chemical Nomenclature and Structure Representation Division (VIII) Committee Meeting Boston, MA, USA, August 18, 2002
    Minutes of the IUPAC Chemical Nomenclature and Structure Representation Division (VIII) Committee Meeting Boston, MA, USA, August 18, 2002 Members Present: Dr Stephen Heller, Prof Herbert Kaesz, Prof Dr Alexander Lawson, Prof G. Jeffrey Leigh, Dr Alan McNaught (President), Dr. Gerard Moss, Prof Bruce Novak, Dr Warren Powell (Secretary), Dr William Town, Dr Antony Williams Members Absent: Dr. Michael Dennis, Prof Michael Hess National representatives Present: Prof Roberto de Barros Faria (Brazil) The second meeting of the Division Committee of the IUPAC Division of Chemical Nomenclature and Structure Representation held in the Great Republic Room of the Westin Hotel in Boston, Massachusetts, USA was convened by President Alan McNaught at 9:00 a.m. on Sunday, August 18, 2002. 1.0 President McNaught welcomed the members to this meeting in Boston and offered a special welcome to the National Representative from Brazil, Prof Roberto de Barros Faria. He also noted that Dr Michael Dennis and Prof Michael Hess were unable to be with us. Each of the attendees introduced himself and provided a brief bit of background information. Housekeeping details regarding breaks and lunch were announced and an invitation to a reception from the U. S. National Committee for IUPAC on Tuesday, August 20 was noted. 2.0 The agenda as circulated was approved with the addition of a report from Dr Moss on the activity on his website. 3.0 The minutes of the Division Committee Meeting in Cambridge, UK, January 25, 2002 as posted on the Webboard (http://www.rsc.org/IUPAC8/attachments/MinutesDivCommJan2002.rtf and http://www.rsc.org/IUPAC8/attachments/MinutesDivCommJan2002.pdf) were approved with the following corrections: 3.1 The name Dr Gerard Moss should be added to the members present listing.
    [Show full text]
  • Mechanistic Study of Methylbenzene Dealkylation in Methanol-To-Olefins
    Journal of Catalysis 369 (2019) 86–94 Contents lists available at ScienceDirect Journal of Catalysis journal homepage: www.elsevier.com/locate/jcat Mechanistic study of methylbenzene dealkylation in methanol-to-olefins catalysis on HSAPO-34 ⇑ Andrew Hwang, Blake A. Johnson, Aditya Bhan Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA article info abstract Article history: Methylbenzenes entrained within the cavities of silicoaluminophosphate zeotype HSAPO-34 react with Received 14 June 2018 methanol in H+-mediated dealkylation to give ethylene and propylene in methanol-to-olefins catalysis. Revised 1 August 2018 Methylbenzenes dealkylation on solid acids is proposed to occur either via the side-chain mechanism, Accepted 14 October 2018 where an exocyclic C@C undergoes successive methylation prior to CAC cleavage for olefin elimination, or the paring mechanism, where ring contraction to a bicyclohexenyl cation precedes CAC cleavage for olefin elimination. Distinct dealkylation mechanisms prescribe distinct combinations of C atoms—from Keywords: aromatic methyl, aromatic ring, and methanol/dimethyl ether—to comprise the olefin product. Site- Methanol-to-olefins specific isotope tracing that distinguishes between isotope labels in aromatic methyl and aromatic ring Methylbenzenes dealkylation Isotope tracing positions for each methylbenzene shows that tetramethylbenzene gives ethylene via the side-chain Site-specific mechanism and penta- and hexamethylbenzene give propylene via the paring mechanism. The ratio of Quantitative 13C NMR propylene selectivity to ethylene selectivity increases in methanol reactions on HSAPO-34 entrained with HSAPO-34 a distribution of methylbenzenes deliberately manipulated towards increasing fractions of penta- and Methylbenzene flash chromatography hexamethylbenzene, corroborating the conclusion that aromatic precursors and dealkylation mecha- nisms for ethylene diverge from those for propylene.
    [Show full text]
  • Amino Mannitol Dehydrogenases on the Azasugar Biosynthetic Pathway
    Send Orders for Reprints to [email protected] 10 Protein & Peptide Letters, 2014, 21, 10-14 Medium-Chain Dehydrogenases with New Specificity: Amino Mannitol Dehydrogenases on the Azasugar Biosynthetic Pathway Yanbin Wu, Jeffrey Arciola, and Nicole Horenstein* Department of Chemistry, University of Florida, Gainesville Florida, 32611-7200, USA Abstract: Azasugar biosynthesis involves a key dehydrogenase that oxidizes 2-amino-2-deoxy-D-mannitol to the 6-oxo compound. The genes encoding homologous NAD-dependent dehydrogenases from Bacillus amyloliquefaciens FZB42, B. atrophaeus 1942, and Paenibacillus polymyxa SC2 were codon-optimized and expressed in BL21(DE3) Escherichia coli. Relative to the two Bacillus enzymes, the enzyme from P. polymyxa proved to have superior catalytic properties with a Vmax of 0.095 ± 0.002 mol/min/mg, 59-fold higher than the B. amyloliquefaciens enzyme. The preferred substrate is 2- amino-2-deoxy-D-mannitol, though mannitol is accepted as a poor substrate at 3% of the relative rate. Simple amino alco- hols were also accepted as substrates at lower rates. Sequence alignment suggested D283 was involved in the enzyme’s specificity for aminopolyols. Point mutant D283N lost its amino specificity, accepting mannitol at 45% the rate observed for 2-amino-2-deoxy-D-mannitol. These results provide the first characterization of this class of zinc-dependent medium chain dehydrogenases that utilize aminopolyol substrates. Keywords: Aminopolyol, azasugar, biosynthesis, dehydrogenase, mannojirimycin, nojirimycin. INTRODUCTION are sufficient to convert fructose-6-phosphate into manno- jirimycin [9]. We proposed that the gutB1 gene product was Azasugars such as the nojirimycins [1] are natural prod- responsible for the turnover of 2-amino-2-deoxy-D-mannitol ucts that are analogs of monosaccharides that feature a nitro- (2AM) into mannojirimycin as shown in Fig.
    [Show full text]
  • HSU-THESIS-2019.Pdf
    EFFECTS OF PRODUCT REMOVAL USING ION-EXCHANGE RESIN AND SODIUM HYDROXIDE PRETREATMENT IN MIXED-CULTURE FERMENTATION A Thesis by SHEN-CHUN HSU Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Chair of Committee, Mark T. Holtzapple Committee Members, Ahmad K. Hilaly Zivko Nikolov Head of Department, M. Nazmul Karim May 2019 Major Subject: Chemical Engineering Copyright 2019 Shen-Chun Hsu ABSTRACT In mixed-culture fermentations of lignocellulosic biomass, periodical product removal has proven to reduce product inhibition and thereby increase biomass digestion. Previously, ion-exchange resin (Amberlite IRA-67) was employed in countercurrent fermentation, and different amounts of resin loadings (10–40 g wet resin per 1.38 L total liquid volume) were studied. Using the pre-established culture (office paper and oven-dried chicken manure), this research used higher resin loadings (50, 60, and 80 g wet resin per 1.34 L total liquid volume). The 0.3-L resin column was sustained by CO2 (gas flow rate: 1.5 L/min). Compared to 30 g resin loading, when higher loadings were introduced, biomass conversion dropped by 0.05–0.09 g NAVSdigested/g NAVSfeed. Furthermore, the yield plateaued at resin loadings greater than 40 g. Overall, the optimal resin loading for both biomass conversion and acid yield was 30–40 resin loading per 1.34 L total liquid volume, which corresponded to 21.74–29.20 g wet resin/Lliq. As indicators of digestibility, cellulase (Ctec3) and hemicellulose (Htec3) were used to saccharify pretreated corn stover.
    [Show full text]