Handbook of 6 Lipid Research

GlycolipidsJ PhosphoglycolipidsJ and Sulfoglycolipids

Handbook of Lipid Research

Editor: Donald J. Hanahan The University of Texas Health Science Center at San Antonio San Antonio, Texas

Volume 1

Volume 2

Volume 3

Volume 4

Volume5

Volume6

Fatty Acids and Glycerides Edited by Arnis Kuksis

The Fat-Soluble Vitamins Edited by Hector F. DeLuca

Sphingolipid Biochemistry Julian N. Kanfer and Sen-itiroh Hakomori

The Physical Chemistry of Lipids: From Alkanes to Phospholipids Donald M. Small

The Phospholipases Moseley Waite

Glycolipids, Phosphoglycolipids, and Suljoglycolipids Edited by Morris Kates

Handbook of 6 Lipid Research

Glycolipids, Phosphoglycolipids, and Sulfoglycolipids Edited by

Morris Kates University of Ottawa Ottawa, Ontario, Canada

Springer Science+Business Media, LLC

Library of Congress Catalog Card Number 88-640002

ISBN 978-1-4899-2518-3 ISBN 978-1-4899-2516-9 (eBook) DOI 10.1007/978-1-4899-2516-9

© 1990 Springer Science+Business Media New York Originally published by Plenum Press, New York in 1990 Softcover reprint of the hardcover 1st edition 1990

All rights reserved

No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher

Contributors

Werner Fischer, Institut fiir Biochemie der Medizinischen Fakultat, U niver­sitat Erlangen-Niirnberg, D-S520 Erlangen, Federal Republic of Ger­many

Jill Gigg, Laboratory of Lipid and General Chemistry, National Institute for Medical Research, London NW7 IAA, England

Roy Gigg, Laboratory of Lipid and General Chemistry, National Institute for Medical Research, London NW7 IAA, England

Mayer B. Goren, Division of Molecular and Cellular Biology, Department of Pediatrics, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado S0206

Morris Kates, Department of Biochemistry, University of Ottawa, Ottawa, Ontario, Canada KIN 6N5

Robert K. Murray, Departments of Biochemistry and Pathology, University of Toronto, Toronto, Ontario, Canada M5S lAS

Rajagopalan Narasimhan, Departments of Biochemistry and Pathology, Uni­versity of Toronto, Toronto, Ontario, Canada M5S lAS

Alexander P. Thllocht, Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan, Canada S7N OW9

tDeceased

v

Preface

The early history and development of the field of glycolipids was concerned mainly with the predominant glycolipids found in higher animal tissues, namely the glycosphingolipids, as has been extensively documented by J. N. Kanfer and S. Hakomori in Volume 3 of this series. The major glycolipids in organisms of the plant kingdom, however, such as bacteria, yeasts and fungi, algae, and higher plants, are glycoglycerolipids, although glycosphingolipids are also present as minor components in these organisms, except for bacteria.

It is of interest that one of the pioneers in glycosphingolipid research, Herbert E. Carter, also pioneered the discovery and structural elucidation of the plant galactosyldiacylglycerols. This class of glycolipids is present in chlo­roplast membranes and must surely be one of the most ubiquitous and abun­dant natural substances in the world, thereby deserving the attention of lipid biochemists. It is therefore surprising to learn that in contrast to the glycosphingolipids, which were discovered in the 1870s, glycoglycerolipids were not discovered until the 1950s. Since that time investigations of the structure and distribution of these glycolipids have proceeded at an exponen­tially increasing rate, and much information is now available for representa­tives of many genera of bacteria, yeasts, algae, and higher plants. Glycoglyce­rolipids have also been identified in animal cells, particularly in the brain, testes, and sperm. At the present time, interest in glycoglycerolipids has shift­ed towards an understanding of their role in membrane structure and func­tion, and such studies are being actively pursued by several research groups.

The present volume will cover the glycoglycerolipids in bacteria (Chap­ters 1 and 2), plants (Chapter 3), and animals (Chapter 4). Bacteria also con­tain phosphoglycoglycerolipids that are associated with lipoteichoic acids, which act as a bridge between the cell wall and the plasma membrane. These anionic glycolipids will also be covered in Chapter 2. Another group of anionic glycolipids, the sulfated glycosylglycerolipids and the plant sulfo­quinovosyldiacylglycerols will be covered in Chapters 1 and 3, respectively.

Apart from the glycoglycerolipids and glycosphingolipids, there are three other glycolipid classes, usually present as minor components in non­animal organisms, that deserve attention. These are the plant glycosylsterols, reviewed in Chapter 3; the acylated carbohydrates, reviewed in Chapter 5; and the glycosylated hydroxy fatty acids, covered in Chapter 6.

In contrast to the lack of knowledge concerning the structure-function relationships of sterol glycosides in plant membranes, much effort has been devoted to investigations on the function of one group of acylated carbohy-

vii

viii Preface

drates, the diacyltrehaloses present in Mycobacteria. These acyl trehaloses and their sulfate esters are believed to be responsible for the toxicity of Mycobac­teria, and the historical development of knowledge in this an~a is presented in detail in Chapter 5. The glycosylated hydroxy fatty acids, which occur in bacteria and yeasts, are also known to have a specific function: they are ex­creted into the growth medium where they act as detergents, enhancing the organism's ability to take up and digest lipid material, such as hydrocarbons. This is described in Chapter 6.

Establishment of the structure of these glycolipids, particularly the glycoglycerolipids has depended and still is dependent on chemical synthesis to provide pure material of known structure and stereochemical configura­tion for comparison with the natural substances. This synthetic material is also useful in investigations of the physical properties and structure-function re­lationships of the natural glycolipids. Development of procedures for the synthesis of acylated trehaloses and of glycoglycerolipids is reviewed in Chap­ter 5 and Chapter 7, respectively.

During the preparation of this volume one of our authors, Alexander "Pat" Tulloch, passed away on February 14, 1987, a victim of leukemia. Pat Tulloch W<!:§ ilfl outstanding carbohydrate chemist and one of the pioneers in the study of the glycosylated hydroxy fatty acids, as is clear from his contribu­tion to this book (Chapter 6). Pat Tulloch will be remembered for his definitive investigations on the chemistry, synthesis, and metabolism of hydroxy fatty acids and their glycosylated derivatives. His premature death represents a great loss to the field of glycolipids and to science generally. For these reasons, I dedicate this volume to the memory of Dr. Alexander P. Tulloch.

There are a number of persons to whom I am indebted for their invalu­able assisUince in preparing the manuscripts for Chapters 1 and 3: Helene Amyot for typing the manuscripts of Chapters 1 and 3 and the front papers, Eva Szabo for preparation of many of,the figures, Paul Brunon for photog­raphy, Clem Kazakoff for the mass spectra, and Raj Capoor for the NMR spectra. The contributors to this volume are grateful to the scientists and publishen who kindly gave permission for citation of published material and for reproduction of published figures.

Morris Kates Ottawa, Canada

Abbreviations

Abbreviations of glycolipid nomenclature (see IUPAC-IUB Lipid Nomen­clature, 1978, Chem. Phys. Lipids 21:159) and other abbreviations used in this volume are as follows:

A c DAG GalAAG GalCer GalDAG Gal2DAG Gal3DAG Gal4 DAG GDAG GGro GGroL GlcDAG Gro GSL LacCer ManDAG PAPS SulfoGalAAG SulfoGalCer SulfoGalDAG

Archaeol Caldarchaeol Diacylglycerol Galactosylacylalkylglycerol Galactoceramide Galactosyldiacylglycerol Digalactosyldiacylglycerol Trigalactosyldiacylglycerol Tetragalactosyldiacylglycerol Glycosyldiacylglycerol Glycosylglycerol Glycoglycerolipid Glucosyldiacylglycerol Glycerol Glycosphingolipid Lactosylceramide Mannosyldiacylglycerol 31- Phosphoadenosine-5 1 -phosphosulfate Sulfatoxygalactosylacylalkylglycerol Sulfatoxygalactosylceramide( cerebroside sulfate) Sulfatoxygalactosyldiacylglycerol

Contents

Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Chapter 1

Glyco-, Phosphoglyco-, and Sulfoglycoglycerolipids of Bacteria

Morris Kates

1.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1.1. Classification and Nomenclature of Glycoglycerolipids . . . . 1 1.1.2. Historical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.2. Glycosyldiacylglycerols in Eubacteria ............................ 3 1.2.1. Extraction, Isolation, and Analysis . . . . . . . . . . . . . . . . . . . . . . . 3 1.2.2. Structure Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.2.3. Distribution in Eubacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 1.2.4. Fatty Acid and Alkyl Chain Composition ................ 41

1.3. Glyco-, Sulfoglyco-, and Phosphoglycoglycerolipids of Archaebacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 1.3.1. Extraction, Isolation, and Quantitation

of Archaebacterial Lipids .............................. 47 1.3.2. Characterization of Archaebacterial Lipids . . . . . . . . . . . . . . 55 1.3.3. Structure Determination.............................. 61 1.3.4. Distribution in Archaebacteria . . . . . . . . . . . . . . . . . . . . . . . . . 72

1.4. Metabolism of Bacterial Glycolipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 1.4.1. Eubacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 1.4.2. Archaebacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

1.5. Physical Properties ........................................... 93 1.5.1. Glycosyldiacylglycerols of Eubacteria . . . . . . . . . . . . . . . . . . . 93 1.5.2. Glycosyl Archaeols or Caldarchaeols of Archaebacteria ... 96

1.6. Membrane Function of Glycolipids . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 1.6.1. Eubacteria.......................................... 104 1.6.2. Archaebacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

1. 7. Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

xii Contents

Chapter 2

Bacterial Phosphoglycolipids and Lipoteichoic Acids

Werner Fischer

2.1. History and Nomenclature.................................. 123 2.1.1. Lipoteichoic Acids and Related Compounds ............ 123 2.1.2. Phosphoglycolipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

2.2. Occurrence and Structure................................... 126 2.2.1. Phosphoglycolipids and Poly(Glycerophosphate)

Lipoteichoic Acids................................... 126 2.2.2. Unusual Lipoteichoic Acid Structures and Related

Macroamphiphiles in Gram-Positive Bacteria........... 138 2.2.3. Taxonomic Note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 2.2.4. Phosphoglycolipids in Mycoplasmatales................ 143 2.2.5. Phosphoglycolipids, Lipoteichoic Acid, and

Glycerophosphate-Containing Capsular Polysaccharides in Gram-Negative Bacteria ............. 144

2.2.6. Fatty Acid Composition of Phosphoglycolipids and Lipoteichoic Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

2.3. Detection, Isolation, and Purification . . . . . . . . . . . . . . . . . . . . . . . . . 151 2.3.1. Phosphoglycolipids ........... ; . . . . . . . . . . . . . . . . . . . . . . 151 2.3.2. Lipoteichoic Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 2.3.3. Behavior of Isolated Lipoteichoic Acids in Water....... 157

2.4. Structure Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 2.4.1. Phosphoglycolipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 2.4.2. Lipoteichoic Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

2.5. Biosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 2.5.1. Phosphoglycolipids.................................. 190 2.5.2. Glycerophosphoglycolipids . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 2.5.3. Lipoteichoic Acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

2.6. Metabolic Fate of Lipoteichoic Acids .......................... 201 2. 7. Cellular Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 2.8. Biological Activities of Lipoteichoic Acids . . . . . . . . . . . . . . . . . . . . . 205

2.8.1. Bacterial Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 2.8.2. Mammalian Organisms.............................. 211 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217

Chapter 3

Glycolipids of Higher Plants, Algae, Yeasts, and Fungi

Morris Kates

3.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 3.1.1. Nomenclature ....................................... 235 3.1.2. Historical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

3.2. Lipid Extraction Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 3.2.1. Higher Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238

Contents xiii

3.2.2. Algae, Diatoms, Yeasts, and Fungi . . . . . . . . . . . . . . . . . . . . . 240 3.2.3. Seeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

3.3. Glycolipid Isolation Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 3.4. Characterization and Structure Analysis of Glycolipids . . . . . . . . . 242

3.4.1. Thin-Layer Chromatography . . . . . . . . . . . . . . . . . . . . . . . . . 242 3.4.2. Spectral Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 3.4.3. Analysis of Molecular Constituents . . . . . . . . . . . . . . . . . . . . 245 3.4.4. Molecular Species Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 3.4.5. Identification of Deacylated Glycolipids ................ 247 3.4.6. Identification of Carbohydrate Structure

and Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 7 3.4.7. Identification of Nonpolar Moieties of

Glycosylsterols and Glycosylceramides . . . . . . . . . . . . . . . . . 24 7 3.5. Structure Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254

3.5.1. Mono- and DigalactosylDAG . . . . . . . . . . . . . . . . . . . . . . . . . . 254 3.5.2. Tri- and TetragalactosylDAG . . . . . . . . . . . . . . . . . . . . . . . . . 257 3.5.3. SulfoquinovosylDAG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 3.5.4. Mono- and Oligoglycosylsterols . . . . . . . . . . . . . . . . . . . . . . . 258 3.5.5. Ceramide Mono- and Oligohexosides (Cerebrosides) . . . . 259 3.5.6. Phytoglycolipid ...................................... 261

3.6. Distribution of Glycolipids ................................... 261 3.6.1. Higher Plants ....................................... 261 3.6.2. Algae, Diatoms, and Cyanobacteria .................... 270 3.6.3. Yeasts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 3.6.4. Fungi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273

3. 7. Fatty Acid and Molecular Species Composition of Glycosyldiacylglycerols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4 3.7.1. Fatty Acid Composition .............................. 274 3.7.2. Positional Distribution·of Fatty Acids and

Molecular Species of GlycosylDAGs . . . . . . . . . . . . . . . . . . . 283 3.8. Metabolism of Glycolipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286

3.8.1. GlycosylDAGs .. .. . .. . .. . .. . .. . .. . .. .. . . .. .. . . .. . . .. . 286 3.8.2. Glycosylsterol and Acylglycosylsterol Biosynthesis . . . . . . . 298 3.8.3. Ceramidehexoside (Cerebroside) Biosynthesis in Fungi .. 300

3.9. Membrane Function of Plant Glycolipids ...................... 302 3.9.1. Structural Role . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 3.9.2. Functional Role in Activity of Protein Complexes ....... 304 3.9.3. Role in Physiological Phenomena..................... 305

3.10. Summary and Conclusions.................................. 308 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308

Chapter 4

Glycoglycerolipids of Animal Tissues

Robert K. Murray and Rajagopalan Narasimhan

4.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 4.2. Isolation of Galactoglycerolipids .............................. 324

:riv Contents

4.3. Methods Used for Analysis of Structure...................... 326 4.4. Galactosyldiacylglycerol (GalDAG) ............................ 330 4.5. Sulfatoxygalactosyldiacylglycerol (Sulfo-GalDAG) . . . . . . . . . . . . . . 332 4.6. Digalactosyldiacylglycerol (Gal2DAG) . . . . . . . . . . . . . . . . . . . . . . . . . 334 4.7. Galactosylacylalkylglycerol (GalAAG) . . . . . . . . . . . . . . . . . . . . . . . . . 335

4.7.1. GalAAG of Brain .................................... 335 4.7.2. GalAAG of Testis and Spermatozoa ................... 335

4.8. Sulfatoxygalactosylacylalkylglycerol (Sulfo-GalAAG) . . . . . . . . . . . . 336 4.8.1. Sulfo-GalAAG of Testis and Spermatozoa . . . . . . . . . . . . . . 336 4.8.2. Sulfo-GalAAG of Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348

4.9. Digalactosylacylalkylglycerol (Gal2AAG) ....................... 349 4.10. Glucoglycerolipids .......................................... 349 4.11. Possible Functions of GGroLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 4.12. Summary .................................................. 354

References................................................. 355

Chapter 5

Mycobacterial Fatty Acid Esters of Sugars and Sulfosugars

Mayer B. Goren

5.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 5.2. Trehalose Mycolate Esters ........... ~....................... 364

5.2.1. History and Nomenclature........................... 364 5.2.2. History of Trehalose-6,6'-Dimycolate . . . . . . . . . . . . . . . . . . 366 5.2.3. Summary of the Early Structural Studies . . . . . . . . . . . . . . 368 5.2.4. Heterogeneity of Trehalose Dimycolates

and of Mycolic Acids................................ 370 5.2.5. Cord Factor Purification: Current Practices,

Infrared Spectrometry ............................... 374 5.2.6. Determination of Structure: Mass

and NMR Spectrometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 5.2.7. Synthesis of Cord Factors and Cord Factor Analogues . . 377 5.2.8. Pseudo-Cord Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 5.2.9. Biological Activities . . . .. . .. . . .. . .. . .. . .. . .. .. . . .. . . . . 391

5.2.10. Trehalose Monomycolates ............................ 408 5.3. Miscellaneous Acylated Trehalose Derivatives of Mycobacteria.. 419

5.3.1. Trehalose Phleates ................................... 419 5.3.2. Pyruvylated Glycolipids from

Mycobacterium smegmatis ............................... 420 5.3.3. Serologically Active Trehalose-Containing

Lipooligosaccharides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 5.3.4. Trehalose Esters of Intermediate Molecular Weight . . . . . 423

5.4. Sulfatides of Mycobacterium tuberculosis ......................... 424 5.4.1. History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 5.4.2. Separation and Purification of Sulfatides . . . . . . . . . . . . . . 425 5.4.3. SL Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427

Contents

5.4.4. Structural Studies on Sl.rl . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 5.4.5. Association of Sulfatides with Virulence............... 445 5.4.6. Distribution of Mycobacterial Sulfatides............... 445 5.4. 7. Synthesis, Biosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446 5.4.8. Biological Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 7

5.5. Epilogue ................................................... 449 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450

Chapter 6

Glycosides of Hydroxy Fatty Acids

Alexander P. Tulloch

6.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463 6.2. Hydroxy Fatty Acid Glycosides from Bacteria................. 463

6.2.1. Characterization of Rhamnolipids from P. aeruginosa . . . . 463 6.2.2. Biosynthesis of Rhamnolipids ......................... 465 6.2.3. Function and Application of Rhamnolipids . . . . . . . . . . . . 465

6.3. Hydroxy Fatty Acid Glycosides from Fungi .................... 466 6.3.1. Characterization of Cellobiosides from Ustilago zeae . . . . . 466 6.3.2. Biosynthesis of Cellobiosides from Ustilago zeae ......... 467 6.3.3. Function and Application of Cellobiosides . . . . . . . . . . . . . 467

6.4. Hydroxy Fatty Acid Glycosides from Yeasts................... 468 6.4.1. Characterization of Sophorolipids

from Torulopsis bombicola . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468 6.4.2. Characterization of Sophorolipids

from Candida bogoriensis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 7 4 6.5. Hydroxy Fatty Acid Glycosides from Plants................... 475

6.5.1. Hydroxy Fatty Acid Glycosides from Convolvulus, Ipomoea, and Pharbitis Species .............. 475

6.5.2. Characterization of Hydroxy Fatty Acid Glycosides from Plants ............................... 476

6.5.3. Function and Application of Hydroxy Fatty Acid Glycosides from Plants . . . . . . . . . . . . . . . . . . . . . . . . . . 4 79

6.6. Determination of Structure of Hydroxy Fatty Acid Glycosides . . 480 6.6.1. Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 6.6.2. Oxidation ........................................... 482 6.6.3. Methylation ......................... ·. . . . . . . . . . . . . . . . 482 6.6.4. Hydrolysis and Related Reactions . . . . . . . . . . . . . . . . . . . . . 483

6. 7. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484

Chapter 7

Synthesis of Glycoglycerolipids

Jill Gigg and Roy Gigg

7.1. Introduction............................................... 489 7.2. Monoglycosylglycerolipids................................... 489

xvi Contents

7.2.1. 1,2-trans-Monoglycosyldiacylglycerols .................. 489 7.2.2. Seminolipid ......................................... 492 7.2.3. 1,2-cis-Glycosyldiacylglycerols . . . . . . . . . . . . . . . . . . . . . . . . . 493 7.2.4. Monoglycosyldialkylglycerols . . . . . . . . . . . . . . . . . . . . . . . . . 496

7 .3. Diglycosylglycerolipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 496 7 .3.1. Diglycosyldiacylglycerols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 496 7.3.2. Diglycosyldialkylglycerols ............................. 500

7 .4. Triglycosylglycerolipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501 7 .4.1. Triglycosyldiacylglycerols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501 7 .4.2. Triglycosyldi-0-Phytanylglycerol ...................... 502 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503

Index .............................. : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507