• Abstract and Figures
• Public Full-text

University of New Hampshire University of New Hampshire Scholars' Repository Doctoral Dissertations Student Scholarship Spring 1980 SOME CHEMICAL CONSTITUENTS OF THE BROWN ALGA, AGARUM CRIBOSUM AND THE EFFECT OF ELECTROSTATIC INTERACTIONS ON THE STEREOCHEMISTRY OF THE S(N)2' REACTION JOAN DEBORAH NEWBURGER Follow this and additional works at: https://scholars.unh.edu/dissertation Recommended Citation NEWBURGER, JOAN DEBORAH, "SOME CHEMICAL CONSTITUENTS OF THE BROWN ALGA, AGARUM CRIBOSUM AND THE EFFECT OF ELECTROSTATIC INTERACTIONS ON THE STEREOCHEMISTRY OF THE S(N)2' REACTION" (1980). Doctoral Dissertations. 1255. https://scholars.unh.edu/dissertation/1255 This Dissertation is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. INFORMATION TO USERS This was produced from a copy of a document sent to us for microfilming. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help you understand markings or notations which may appear on this reproduction. 1. The sign or “target” for pages apparently lacking from the document photographed is “Missing Page(s)”. If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure you of complete continuity. 2. When an image on the film is obliterated with a round black mark it is an indication that the film inspector noticed either blurred copy because of movement during exposure, or duplicate copy. Unless we meant to delete copyrighted materials that should not have been filmed, you will find a good image of the page in the adjacentTrame. 3. When a map, drawing or chart, etc., is part of the material being photo­ graphed the photographer has followed a definite method in “sectioning” the material. It is customary to begin filming at the upper left hand corner of a large sheet and to continue from left to right in equal sections with small overlaps. If necessary, sectioning is continued again—beginning below the first row and continuing on until complete. 4. For any illustrations that cannot be reproduced satisfactorily by xerography, photographic prints can be purchased at additional cost and tipped into your xerographic copy. Requests can be made to our Dissertations Customer Services Department. 5. Some pages in any document may have indistinct print. In all cases we have filmed the best available copy. University Microfilms International 300 N. ZEEB ROAD, ANN ARBOR, Ml 48106 18 BEDFORD ROW, LONDON WC1 R 4EJ, ENGLAND 8027795 N e w b u r g e r, Jo a n D e b o r a h SOME CHEMICAL CONSTITUENTS OF THE BROWN ALGA, AGARUM CR1BOSUM AND THE EFFECT OF ELECTROSTATIC INTERACTIONS ON THE STEREOCHEMISTRY OF THE S(N)2’ REACTION University o f New Hampshire Ph.D. 1980 University Microfilms International300 N. Zeeb Road, Ann Arbor, MI 48106 18 Bedford Row, London WC1R 4EJ, England PLEASE NOTE: In all cases this material has been filmed in the best possible way from the available copy. Problems encountered with this document have been identified here with a check mark v ' ' . 1. Glossy photographs _______ 2. Colored illustrations _______ 3. Photographs with dark background_ ______ 4. Illustrations are poor copy 5. °rint shows through as there is text on both sides of page _______ 6. Indistinct, broken or small print onseveral pages s / 7. Tightly bound copy with print lost in spine _______ 8. Computer printout pages with indistinct print _______ 9. Page(s) ____ lacking when material received, and not available from school or author 10. Page(s) _______ seem to be missing in numbering only as text follows 11. Poor carbon copy _______ 12. Not original copy, several pages with blurred type ____ 13. Appendix pages are poor copy _______ 14. Original copy with light type _______ 15. Curling and wrinkled pages ____ _ 16. Other University M icrdnims international 300 N ZEES RD.. ANN AR30B Ml 48106'31 31 761-4700 SOME CHEMICAL CONSTITUENTS OF THE BROWN ALGA, AGARUM CRIBOSUM And THE EFFECT OF ELECTROSTATIC INTERACTIONS ON THE STEREOCHEMISTRY OF THE Sn 2' REACTION By JOAN D. NEWBURGER B. A. , Grinnell College, 1974 A DISSERTATION Submitted to the University of New Hampshire in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY in CHEMISTRY May, 1980 This dissertation has been examined and approved. John Uebel ;try Paul R. Jones, gzofessor of Chemistry r f c w o l $ > , _____________ Jairtes D. Morrison, Professor o£ Chemistry Alexander R. Amell, Professor of Chemistry 4 A S Miyoshi/'Ikawa, Professor of Biochemistry % m o DdEe DEDICATION This dissertation is dedicated with great love and affection to my parents, Adele and Sylvan, and to my sister, Harriet. ACKNOWLEDGMENT I wish to express my sincere gratitude and appreciation to my advisor, Dr. J. John Uebel, for his invaluable guidance and encouragement during the course of my graduate education and dissertation research. I would also like to thank Dr. Paul R. Jones and, in particular, Dr. Kenneth K. Andersen for their help during the sabbatical year of Dr. Uebel. I wish to thank Dr. Arthur Matheson and his students for their considerable assistance in the phycological aspects of my work. I wish to thank Dr. Robert Gagosian of the Woods Hole •4 Institution of Oceanography for his collaboration on the sterol research and Dr. Cathy Costello of the Massachusetts Institute of Technology for her help in the fatty acid data collection and for high resolution mass spectra. For their technical assistance, I wish to acknowledge Michael Pazdon and Kathy Gallager. In particular, Mike spent many hours helping me with the HPLC and GC/MS instru­ ments . For their help in the preparation of this manuscript, I wish to thank Diana Schuman and Dee Cardin. I am grateful to the Chemistry Department for financial support in the form of a Teaching Assistantship and to the Leslie S. and Iola Hubbard Marine Program Fund for summer financial support and funding for supplies. A very special acknowledgment is due Dr. Gene Wubbels of Grinnell College and Dr. Edward Radford of the University of Pittsburgh (formerly of Johns Hopkins University) for their advice, encouragement, and understanding during my undergraduate career. V ABSTRACT SOME CHEMICAL CONSTITUENTS OF THE BROWN ALGA, AGARUM CRIBOSUM AND THE EFFECT OF ELECTROSTATIC INTERACTIONS ON THE STEREOCHEMISTRY OF THE SN2 ' REACTION by JOAN D. NEWBURGER University of New Hampshire, May 1980 Part 1: Some Chemical Constituents of the Brown Alga, Agarum cribosum. Agarum cribosum was examined for major chemical con­ stituents. Halogenated terpenes found in red algae were not present in this seaweed. The sterol content was de­ termined by GC/MS analysis and six sterols were identi­ fied: fucosterol, 24-methylenecholesterol, cholesterol, 24-ketocholesterol, saringosterol, and desmosterol. The presence of desmosterol in brown algae had not been pre­ viously confirmed. A seventh sterol could not be identified from its mass spectrum. The fatty acid content was also determined by GC/MS analysis. The major fatty acids were ^16-0’ ^16*1’ ^ 2 0 - 4 anc* ^ 2 2 -5 ‘ suSar mannitol was isolated. Part 2: The Effect of Electrostatic Interactions on the Stereochemistry of the SN2' Reaction. The stereochemistry of the S^2' reaction was studied using (trans-6 -t-butyl-2 -cyclohexen-l-yl)trimethylammo- nium tetrafluoroborate as a substrate for nucleophilic attack. The substrate was reacted with two nucleophiles, piperidine and sodium propanethiolate. To the extent that transition state electrostatic interactions can influence the direction of nucleophilic attack, it was expected that piperidine would attack anti to the leav­ ing group while propanethiolate would attack syn. The experiments confirmed these predictions, piperidine attacking 80% anti and propanethiolate attacking 92% syn, It was concluded that transition state electro­ static interactions play a role in determining the di­ rection of nucleophilic attack. TABLE OF CONTENTS ABSTRACT ................................................ vi LIST OF TABLES (Part 1) xii LIST OF FIGURES (Part 1 ) ............................... xiii LIST OF TABLES (Part 2) xvii LIST OF FIGURES (Part 2 ) .............................. xviii PART 1: SOME CHEMICAL CONSTITUENTS OF THE BROW ALGA, Agarum Cribosum ........................ 1 I. INTRODUCTION .................................... 2 II. RESULTS AND DISCUSSION ........................... 21 1. Column Chromatography Separation ........... 21 2. Sterols of Agarum cribosum .................. 24 3. Fatty Acids of Agarum cribosum .............. 50 4. Isolation of Mannitol ...................... 67 III. EXPERIMENTAL...................................... 69 G e n e r a l .......................................... 69 Extraction of Agarum cribosum ................. 70 Open Column Chromatography of Nonpolar Constituents ............................... 70 Saponification of Crude Extract ............... 71 Separation of Non-saponifiable Lipids .......... 72 Identification of Sterol Compounds ............. 72 Isolation of Fucosterol from Ascophyllum

Load more

  255

Copy Link