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An Evaluation of the Enantiomeric Recognition of Amino Acid Based Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2005 An evaluation of the enantiomeric recognition of amino acid based polymeric surfactants and cyclodextrins using spectroscopic and chromatographic methods Bertha Cedillo Valle Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Chemistry Commons Recommended Citation Valle, Bertha Cedillo, "An evaluation of the enantiomeric recognition of amino acid based polymeric surfactants and cyclodextrins using spectroscopic and chromatographic methods" (2005). LSU Doctoral Dissertations. 3349. https://digitalcommons.lsu.edu/gradschool_dissertations/3349 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. AN EVALUATION OF THE ENANTIOMERIC RECOGNITION OF AMINO ACID BASED POLYMERIC SURFACTANTS AND CYCLODEXTRINS USING SPECTROSCOPIC AND CHROMATOGRAPHIC METHODS A Dissertation Submitted to the graduate Faculty of the Louisiana State University and Agricultural and Mechanical College In partial fulfillment of the Requirements for the degree of Doctor of Philosophy in The Department of Chemistry By Bertha Cedillo Valle B.S. Texas Tech University, 1998 December 2005 DEDICATION I want to dedicate this work to my husband, Larry, and my immediate siblings, Octavio Jorge, Martha, and Silvia, along with their respective spouses. You guys were a constant driving force for me and were always there to support me financially and/or emotionally. I appreciate your support more than words can say. I hope that I can return the favor one day. ii ACKNOWLEDGEMENTS I would like to graciously acknowledge the support of the many people that made the completion of this work possible. My mother and father, Octavio and Mercedes Cedillo for leaving your home country to establish a new life so that I may have a better chance at excelling in life. Thank you also for encouraging me to follow my dreams no matter where they took me. My parents-in-law, Abel and Gloria Valle, for your constant words of encouragement and emotional support. Dr. Isiah Warner, for all your support both financially and professionally but most of all for your fatherly concern for my future. I could not have done it without your undoubted belief in me. Dr. Shahab A. Shamsi, for our collaborations in research and in manuscript writing. Dr. Rezik A. Agbaria, for teaching me everything about fluorescence and life in general. Dr. Kevin Morris, for a seemingly effortless collaboration involving the understanding of chiral interactions using PFG-NMR and 2D-NMR. Constantina Kapnissi, PhD., for your faithful friendship that I will remember always. Karen A. Prado, for your hard work and dedication to our research and especially for allowing me into your home. Thank you for being the “sister” I needed. Judson L. Haynes, PhD., for your constant personal and professional mentoring. Charles W. Henry, PhD., for being my “big brother” during and after grad school. Dr. Matthew McCarroll, for teaching me all about instrumentation and electronics. iii Kristin A. Fletcher, PhD., for the speedy return of my manuscripts as well for listening and caring about my problems both professional and personal. I could not have done it with out your friendship. Warner Research Group, for all the experiences that made me to grow both as a scientist and as an individual. Dr. Purnendu P. Dasgupta, for allowing me to be a part of your group and giving me the opportunity to learn how to do research. Dr. Dennis L. Shelly, the wonderful time I had working for you and for making me come to LSU for a visit. Dr. Carl J. Popp, for the incredible summer I spent in New Mexico working on M mountain and for your excellent letter of recommendation that eventually got me in to LSU. My husband, Larry A. Valle, for hanging in there with me while we lived apart for over four years of our marriage. Thank you for putting your life on hold for me. I hope to make our future worth the wait. iv TABLE OF CONTENTS DEDICATION…………………………………………………………………………… ii ACKNOWLEDGEMENTS……………………………………………………………… iii LIST OF TABLES……………………………………………………………………….. viii LIST OF FIGURES……………………………………………………………………….ix LIST OF ABBREVIATIONS……………………………………………………………. xiii ABSTRACT……………………………………………………………………………… xvi CHAPTER 1.INTRODUCTION………………………………………………………… 1 1.1 Chirality and Its Significance……………………………………. 1 1.2 Fundamentals of Capillary Electrophoresis………………………5 1.3 Capillary Zone Electrophoresis (CZE)……………………………7 1.4 Micellar Electrokinetic Chromatography………………………... 11 1.5 Chiral Selectors for Chiral CE…………………………………… 17 1.5.1 Polymeric Surfactants……………………………………. 17 1.5.2 Native Cyclodextrins and Their Derivatives……………... 21 1.5.3 Ligand-Exchange Metal Complexes……………………... 24 1.5.4 Crown Ethers……………………………………………...26 1.5.5 Macrocyclic Antibiotics………………………………….. 28 1.6 Theory of Fluorescence Spectroscopy…………………………… 29 1.6.1 Polarization of Photoluminescence………………………. 33 1.7 Nuclear Magnetic Resonance (NMR)……………………………. 36 1.7.1 Pulsed-Field Gradient NMR……………………………... 39 1.7.2 Nuclear Overhauser Effect Spectroscopy NMR…………. 42 1.8 Scope of Dissertation…………………………………………….. 45 1.9 References………………………………………………………... 47 CHAPTER 2. COMBINATION OF CYCLODEXTRINS AND POLYMERIC SURFACTANTS FOR CHIRAL SEPARATIONS……………………... 54 2.1 Introduction………………………………………………………. 54 2.2 Experimental……………………………………………………... 56 2.2.1 Materials and Reagents…………………………………... 56 2.2.2 Synthesis of Polymeric Chiral Surfactant………………... 58 2.2.3 Capillary Electrophoresis Procedure…………………….. 60 2.3 Results and Discussion…………………………………………... 61 2.3.1 Elution Order of Binaphthyl Derivatives as a Function of CD Cavity Size and the Stereochemical Configuration of Polymeric Surfactants…………………………………. 61 2.3.2 Enantioseparation of BNA……………………………….. 62 2.3.3 Enantioseparation of BOH……………………………….. 65 v 2.3.4 Enantioseparation of BNP………………………………... 70 2.4 Conclusions………………………………………………………. 72 2.5 References………………………………………………………... 73 CHAPTER 3. POLYSODIUM N-UNDECANOYL-L-LEUCYLVALINATE: A VERSATILE CHIRAL SELECTOR FOR MICELLAR ELECTROKINETIC CHROMATOGRAPHY………………………….. 75 3.1 Introduction………………………………………………………. 75 3.2 Experimental……………………………………………………... 77 3.2.1 Materials…………………………………………………. 77 3.2.2 Instrumentation…………………………………………... 77 3.2.3 Synthesis of Polysodium N-undecanoyl-L-leucylvalinate.. 78 3.2.4 Determination of Partial Specific Volume……………...... 78 3.2.5 Preparation of MEKC Buffers and Analyte Solutions…… 79 3.2.6 Capillary Electrophoresis Procedure…………………….. 79 3.3 Results and Discussion…………………………………………... 79 3.3.1 Enantioseparation of Class I Analytes…………………… 80 3.3.2 Enantioseparation of Class II Analytes………………….. 86 3.3.3 Enantioseparation of Class III Analytes…………………. 94 3.4 Conclusions………………………………………………………. 99 3.5 References………………………………………………………... 100 CHAPTER 4. UNDERSTANDING CHIRAL SEPARATIONS INVOLVING P-(SULV) USING STEADY-STATE FLUORESCENCE ANISOTROPY, CAPILLARY ELECTROPHORESIS, AND NMR……………………... 102 4.1 Introduction……………………………………………………… 102 4.1.1 Nuclear Magnetic Resonance Theory……………………. 103 4.1.2 α vs. β Theory……………………………………………. 104 4.2 Experimental…………………………………………………….. 106 4.2.1 Materials and Reagents…………………………………... 106 4.2.2 Dansyl Amino Acid (Dns-AA) Derivatization…………... 107 4.2.3 Prep-TLC………………………………………………… 108 4.2.4 Synthesis of Polysodium N-Undecanoyl- (L,L)-Leucylvaline, p-(L-SULV), and Its Diastereomers………………………………………….. 109 4.2.5 Centrifugal Filtration…………………………………….. 109 4.2.6 Capillary Electrophoresis Instrumentation and Procedures………………………………………………... 109 4.2.7 Background Electrolyte (BGE) and Capillary Electrophoresis Standard Preparation……………………. 110 4.2.8 Selectivity Calculation…………………………………… 110 4.2.9 Fluorescence Spectroscopy Instrumentation and Procedures………………………………………………... 111 4.3 Results and Discussion…………………………………………... 113 4.3.1 MEKC Results…………………………………………… 113 4.3.2 Nuclear Overhauser Effect Spectroscopy (NOESY) vi Results ………………………………………………….. 117 4.3.3 Steady-State Fluorescence Spectroscopy Result………… 124 4.4 Conclusions………………………………………………………. 132 4.5 References………………………………………………………... 133 CHAPTER 5. CONCLUSIONS AND FUTURE DIRECTIONS………………………. 137 APPENDIX I PLOT OF THE CORRELATION BETWEEN THE α VALUES DERIVED FROM MEKC EXPERIMENTS AND β-VALUES DERIVED FROM FLUORESCENCE………………………………………………. 142 APPENDIX II DIGITAL PHOTOGRAPHS OF PREP TLC…………………... 143 APPENDIX III MEKC ENANTIOSEPARATION OF THE ENANTIOMERS OF SEVEN ANALYTES …………………………………………………….. 146 APPENDIX IV TITRATION CURVES SHOWING THE A) ENANTIOMER ANISOTROPY AND B) CHIRAL SELECTIVITY OF BOH AND DNS-PHE………... 153 APPENDIX V α VS. β PLOTS OBTAINED USING p-(L,D)-SULV AND p-(D,L)-SULV AS THE CHIRAL SELECTORS…………………………………………………….. 155 APPENDIX VI EXPERIMENTAL CONDITIONS USED IN THE PFG NMR STUDIES………………………………………………………… 157 APPENDIX VII RAW 2-D NOE PLOTS FOR ANALYTES IN CHAPTER 4.….. 158 VITA……………………………………………………………………………………... 163 vii LIST OF TABLES Table Page 1.1 Activities of select chiral compounds……………………………………………. 3 1.2 Brief description of six modes of capillary electrophoresis……………………… 6 1.3 Critical micelle concentrations (CMC) and aggregation numbers (AN) of select surfactants [18]…………………………………………………………. 14 1.4 Important characteristics of α-, β-, and γ-CDs
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