Polyether antibiotics : naturally occurring acid ionophores / Volume 2, Chemistry

This collection of essays will stimulate the use of ionophores in different research areas. It includes information on potential breakthroughs in the halogenated derivatives of lasalocid and ethers of antibiotic A204A, polyethers and analytical techniques used to unravel their complex structures. Cover 1 Half Title 3 Title Page 5 Copyright Page 6 Table of Contents 11 Foreword 7 Preface 9 List of Contributors 13 Contents of Volume 1—Biology 15 1. Chemical Synthesis 19 I. Introduction 20 II. Synthetic Methods 20 A. β-Hydroxy Ketone 20 B. Spiroketal 21 C. Tetrahydrofurans 27 D. Tetrahydropyrans 30 E. 1,2-Stereochemistry 31 F. Chiral Starting Materials 33 III. Total Syntheses 33 A. A23187 (Calcimycin) 33 B. Evans Synthesis 33 C. Grieco Synthesis 35 D. Ogawa Synthesis 38 E. Lasalocid A (X-537A) 38 F. Kishi Synthesis 38 G. Ireland Synthesis 45 H. Monesin 48 I. Kishi Synthesis 48 J. Still Synthesis 56 References 64 Bibliography 66 2. Chemical Transformations of Polyether Antibiotics 69 I. Introduction 69 II. Lasalocid 70 A. Chemical Modifications 70 B. Biological Activity 81 III. Monensin and Dianemycin 84 IV. Nigericin and X-206 86 V. Antiobiotic A204 88 A. Chemical Modifications 88 B. Biological Activity 89 VI. Grisorixin and Alborixin 91 VII. Lysocellin 94 A. Chemical Modifications 94 B. Biological Activity 96 VIII. Lonomycin 97 A. Chemical Modifications 97 B. Biological Activity 98 IX. Salinomycin 99 X. Conclusions 100 References 101 3. X-Ray Structures of the Polyether Antibiotics 105 I. Introduction 105 II. Polyether Antibiotics 114 III. Conclusion 206 References 209 4. Mass Spectrometry of Polyether Antibiotics 215 I. Introduction 215 II. General Considerations 216 III. Alborixin Group 219 IV. Dianemycin Group 223 V. Lasalocid Group 226 VI. Lysocellin Group 229 VII. Miscellaneous Group 233 VIII. Monensin Group 237 IX. Nigericin Group 241 X. Noboritomycin Group 250 XI. Salinoraycin Group 253 XII. Summary 257 References 258 5. Structure, Conformation, and Mechanism of Action as Revealed by Proton NMR 263 I. Introduction 264 Scope and Limitations of [sup(1)]H NMR Spectroscopy 265 II. Stereo Notation and Coding 269 A. Symbols 269 B. Structural Representations of Some Carboxylic Acid Lonophores 271 C. Stereoviews 271 D. Spectral Representations 285 III. Applied Methodology and Criteria 291 A. General Considerations 291 B. Operational Strategies 295 C. [sup(1)]H Chemical Shifts and Their Predictability 299 D. Coupling Constants and Conformation 302 E. Hydroxy Groups 313 F. ASIS Effects and Lipophilicity Index 325 IV. Primary Structure and Predestination to Conformational Bias 333 A. General Considerations: Definition of Hinges 333 B. Conformational Rules 334 C. Practical Applications of Conformational Rules: Static and Dynamic Features 337 V. Conclusion 342 References 342 6. [sup(13)]C NMR Spectra of Polyether Antibiotics 353 I. Introduction 354 II. Techniques Used for [sup(13)]C Assignments of Polyether Antibiotics 354 A. Differentiation of Methyl, Methylene, Methine, and Quaternary Carbon Signals 355 B. Selective Proton Decoupling 356 C. Biosynthetic Labeling Method 358 III. Classification of Polyether Antibiotics 359 IV. [sup(13)]C NMR Spectra of Polyether Antibiotics 362 A. Group 1 363 B. Group 2 378 C. Group 3 383 D. Group 4 396 E. Group 5 400 V. [sup(13)]C Chemical Shift Trends of Polyether Antibiotics 403 A. Some Empirical Rules for the Structural Elucidation of Polyether Antibiotics by [sup(13)]C NMR Spectroscopy 403 B. Application of the "Empirical Rules" for the Structural Elucidation of Antibiotic 6016 410 VI. Conclusion 412 References 413 Author Index 419 Subject Index 431 Chemical,Synthesis;,Polyether,Antibiotics;,X-ray,Structures;,Mass,Spectrometry;,Proton,NMR Chemical Synthesis,Polyether Antibiotics,X-ray Structures,Mass Spectrometry,Proton NMR Exposes The Anxieties Of Loss Of Control And Missed Opportunities For Greater Freedom Of Expression Resulting From Changes In Technologies And Geopolitics.-- Vast Changes In Technologies And Geopolitics Have Produced A Wholesale Shift In The Way States And Other Powerful Entities Think About The Production And Retention Of Popular Loyalties. Strategic Communication Has Embraced These Changes As Stakes Increase And The Techniques Of Information Management Become More Pervasive.-- V. 1. Biology -- V. 2. Chemistry. Edited By John W. Westley. Includes Bibliographies And Indexes.