ETHNOPHARMACOLOGY, PHYTOCHEMISTRY AND BIOLOGICAL ACTIVITIES OF MALIAN MEDICINAL PLANTS Thesis for the Degree of Philosophiae Doctor PhD DEGREE Adiaratou Togola DEPARTMENT OF PHARMACEUTICAL CHEMISTRY SCHOOL OF PHARMACY UNIVERSITY OF OSLO NORWAY Oslo, 2008 © Adiaratou Togola, 2008 Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo Nr. 734 ISSN 1501-7710 All rights reserved. No part of this publication may be reproduced or transmitted, in any form or by any means, without permission. Cover: Inger Sandved Anfinsen. Printed in Norway: AiT e-dit AS, Oslo, 2008. Produced in co-operation with Unipub AS. The thesis is produced by Unipub AS merely in connection with the thesis defence. Kindly direct all inquiries regarding the thesis to the copyright holder or the unit which grants the doctorate. Unipub AS is owned by The University Foundation for Student Life (SiO) CONTENTS ACKNOWLEDGEMENTS ......................................................................................................................................... 4 ABSTRACT .................................................................................................................................................................. 6 LIST OF ABBREVIATIONS AND SYMBOLS ........................................................................................................ 9 LIST OF PAPERS ...................................................................................................................................................... 11 1. INTRODUCTION .................................................................................................................................................. 13 1.1. TRADITIONAL MEDICINE ................................................................................................................................... 13 1.2. ETHNOPHARMACOLOGY .................................................................................................................................... 15 1.3. PLANT POLYSACCHARIDES ................................................................................................................................ 17 1.3.2. Hemicellulose ........................................................................................................................................... 18 1.3.3. Pectic polysaccharides ............................................................................................................................. 18 1.3.4. Arabinogalactans ...................................................................................................................................... 20 1.4. WOUNDS ........................................................................................................................................................... 21 1.5. THE IMMUNE SYSTEM ........................................................................................................................................ 23 1.5.1. The complement system ............................................................................................................................ 24 1.5.2. Macrophages ............................................................................................................................................ 28 1.6. IMMUNOSTIMULATORY ACTIVITY OF PLANTS POLYSACCHARIDES ..................................................................... 29 1.7. PLANT SECONDARY METABOLITES .................................................................................................................... 31 1.7.1. Flavonoids as antimicrobial agents from plants ....................................................................................... 31 1.7.2. Flavonoids as lipoxygenase inhibitors ...................................................................................................... 34 1.8. PLANTS USED IN THIS STUDY ............................................................................................................................. 35 1.8.1. Opilia celtidifolia ...................................................................................................................................... 35 1.8.2. Cola cordifolia .......................................................................................................................................... 36 1.8.3 Erythrina senegalensis ............................................................................................................................... 37 2. AIM OF THE STUDY ........................................................................................................................................... 39 3. SUMMARY OF RESULTS ................................................................................................................................... 40 3.1. PAPER I AND II .................................................................................................................................................. 40 3.2. PAPER III ........................................................................................................................................................... 41 RESULTS OF UNPUBLISHED STUDIES ON O. CELTIDIFOLIA POLYSACCHARIDES .......................................................... 41 3.3. PAPER IV ........................................................................................................................................................... 46 3.4. PAPER V ............................................................................................................................................................ 47 4. GENERAL DISCUSSION ..................................................................................................................................... 48 4.1. ETHNOPHARMACOLOGICAL INFORMATION ........................................................................................................ 48 4.2. STRUCTURES OF ISOLATED COMPOUNDS ........................................................................................................... 50 4.2.1. Polysaccharides ........................................................................................................................................ 50 4.2.2. Low molecular weight compounds ............................................................................................................ 56 4.3. BIOLOGICAL ACTIVITIES ................................................................................................................................... 57 4.3.1. Polysaccharides ........................................................................................................................................ 57 4.3.2. Low molecular weight compounds ............................................................................................................ 59 5. CONCLUDING REMARK ................................................................................................................................... 61 6. METHODOLOGY ................................................................................................................................................. 62 6.1. EXTRACTION AND ISOLATION PROCEDURES ...................................................................................................... 62 6.1.1. Polysaccharides ........................................................................................................................................ 62 6.1.2. Low molecular weigh compounds ............................................................................................................. 62 6.2. QUANTIFICATION OF FRACTION COMPONENTS ................................................................................................... 62 6.2.1 Polysaccharides ......................................................................................................................................... 62 6.2.2. Proteins ..................................................................................................................................................... 63 2 6.2.3. Phenols ..................................................................................................................................................... 63 6.3. STRUCTURE ANALYSIS ....................................................................................................................................... 64 6.3.1. Reduction of uronic acid ........................................................................................................................... 64 6.3.3. GC and GC-MS......................................................................................................................................... 65 6.3.4. NMR, MS .................................................................................................................................................. 65 6.3.5. Enzymatic degradation ............................................................................................................................. 66 6.3.6. Precipitation with Yariv ȕ-glucosyl reagent ............................................................................................. 66 6.3.7. Periodate oxidation .................................................................................................................................. 66 6.4. ESTIMATION OF MOLECULAR WEIGHT DISTRIBUTION .......................................................................................