General Introduction
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Ethnopharmacological survey and phytochemical investigation of Maasai traditional medicinal plants from north-eastern Tanzania Dissertation Submitted to the Faculty of Chemistry and Pharmacy, University of Regensburg for the degree of Doctor of Natural Sciences (Dr. rer. nat.) Presented by Edna Makule From Arusha, Tanzania 2015 Gedruckt mit Unterstutzung des Deutschen Akademischen Austauschdienstes. General introduction The present work was carried out from October, 2012 until November, 2015 under the supervision of Prof. Dr. Jörg Heilmann and Dr. Birgit Kraus at the Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg. Dissertation submitted on: 16. 11. 2015 Oral presentation on: 21. 12. 2015 Examination committee: PD Dr. Sabine Amslinger (Chairperson) Prof. Dr. Jörg Heilmann (First examiner) Prof. Dr. Ulrike Lindequist (Second examiner) Prof. Dr. Gerhard Franz (Third examiner) Acknowledgements First and foremost, I would like to thank the almighty GOD who is the essence of everything for giving me life and immense strength throughout the course of this PhD work. For him all things are possible. I am sincerely grateful to my supervisor Prof. Dr. Jörg Heilmann, for having trust in me in the first place and giving me an opportunity to pursue my PhD studies under his supervision. His expertise, generous support, guidance, valuable ideas and suggestions, have made it possible for me to accomplish the work on the topic that was interesting for me. My heartfelt gratitude to my co-supervisor Dr. Birgit Kraus, for her kind supervision, tireless guidance, encouragement, problems solving ability, valuable suggestions, constructive ideas throughout the time of my doctorial research. Besides, a friend to rely on. I am indebted to her more than she knows. I am thankful to Dr. Guido Jürgenliemk for introducing me to the first analytics procedures, his willingness to help, advice, comments, corrections, as well as for providing tips and analytical tricks whenever I consulted him, were honored. I would like to thank Mrs. Gabriele Brunner for her technical advice during the whole period of my lab work and tips for column chromatography. I am thankful to all my colleagues, who have finished and those who are still pursuing the PhDs at the department of Pharmaceutical Biology - University of Regensburg: Dr. Sebastian Schmidt, Dr. Marcel Flemming, Dr. Daniel Bücherl, Dr. Rosmarie Scherübl, Dr. Petr Jirásek, Dr. Beata Kling, Dr. Tri Hieu Nguyen, Monika Untergehrer, Markus Löhr, Stefan Wiesneth, Eva Lotter, Ilya Volkov, Christian Zeh, Katharina Schiller, Julianna Ziegler, Sebastian Schwindl and Sina Malenke. I appreciate their valuable help, technical discussions and mutual support which made my work in the lab smooth and enjoyable. My sincere appreciations are extended to the following: Mr. Fritz Kastner at the NMR department – University of Regensburg, for performing all the NMR measurements. Mr. Josef Kiermaier at the Mass spectrometry department- University of Regensburg, for carrying out all mass spectra measurements. PD Dr. Axel Dürkop from the department of Analytical Chemistry – University of Regensburg, for performing measurements of all the CD spectra. Prof. Dr. Thomas Schmidt from the Institute of Pharmaceutical Biology and Phytochemistry – University of Münster, for carrying out CD calculations. Mr. Daniel Sitoni from Tanzania National Herbarium, Arusha, and Mr. Canisius Kayombo from Olmotonyi Forestry Institute, Arusha, for a great assistance in plants identification during ethnopharmacological field work. Mr. Victor Makundi for analyzing the GPS data recorded during ethnopharmacological field work and fixing them in the map. I am grateful to the Ministry of Education and Vocational Training (MoEVT) - Tanzania and Deutscher Akademischer Austausch Dienst (DAAD) – Germany, for financial support that has enabled me to pursue and successfully complete PhD studies in Germany. I am indebted to my employer Nelson Mandela African Institute of Science and Technology (NM-AIST), Arusha, for granting me a study leave and for financial support to carry out field work on ethnopharmacological survey. My special thanks goes to my lovely children Irene Emily, Emmy Claire and Godlisten for having patience on me all the time I was not at home because of my studies. It is my prayer that you live to enjoy the outcomes. I owe my loving thanks to my husband Mecku for his understanding, positive attitude, support, sacrifices and above all for taking care of the family without complaints all the time I was not at home. Without his great support and encouragements it would have been impossible for me to finish this work. Lastly, and most importantly, I am indebted to my parents Edward and Felister for their unconditional love, prayers and for raising me to be the person I am today. May GOD bless you abundantly, grant you good health, happiness, peace, prosperity and long life. Edna Makule Regensburg - November, 2015 This thesis work is dedicated to: 1. My loving husband Mecku R. Kessy For all the love, support, patience and words of encouragement. You have made this time a truly wonderful experience in my life. I can’t find words to utter but to say, “Thank you for being so kind and loving”. 2. My beautiful girls Irene Emily & Emmy Claire It was such a difficult moment for you being at home without Mama around. You could not clearly explain the feelings you had, but you kept asking this question; Mama when are you coming back home? This question nailed my heart day and night. It also motivated me to work hard so that I can accomplish the goals and be with you again my sweet angels. List of abbreviations 1D One-dimensional 2D Two-dimensional δ Chemical shift J Coupling constant brs Broad singlet CD Circular dichroism COSY Correlated spectroscopy COX Cyclooxygenase CPC Centrifugal partition chromatography d Doublet dd Doublet of doublet DCM Dichloromethane EtOAc Ethylacetate EtOH Ethanol HCl Hydrochloric acid HIV Human Immunodeficiency Virus HMBC Heteronuclear multiple bond correlation HP HPLC method HPLC High performance liquid chromatography HRESI-MS High resolution electron spray ionization-mass spectrometry HSQC Heteronuclear single quantum coherence HTs Hydrolysable tannins LC-MS Liquid chromatography-mass spectrometry m Multiplets MeCN Acetonitrile MeOH Methanol MHz Megahertz MP Mobile phase MS Mass spectrometry NMR Nuclear magnetic resonance NOESY Nuclear overhauser enhancement spectroscopy NP-TLC Normal phase thin layer chromatography PAs Proanthocyanidins PE Petrol ether extract ppm Parts per million Rf Retardation factor ROESY Rotating-frame nuclear overhauser effect correlation spectroscopy rpm Revolutions per minute s Singlet SMB Per-O-(S)-2-methylbutyrate STDs Sexual transmitted diseases TFA Trifluoroacetic acid TDDFT Time dependent density functional theory TLC Thin layer chromatography TMP Traditional medicinal practitioner TNH Tanzania National Herbarium tR Retention time UV Ultraviolet Table of Contents 1 General introduction .................................................................................................................. 1 1.1 Traditional medicine in Tanzania ......................................................................................... 1 1.2 Aim of the research work .................................................................................................... 3 2 Ethnopharmacological survey of four Maasai traditional medicinal plants ................................... 4 2.1 The Maasai ......................................................................................................................... 4 2.1.1 Culture ................................................................................................................................... 4 2.1.2 Maasai and medicinal plants utilization................................................................................ 7 2.2 Surveyed medicinal plants ................................................................................................... 8 2.2.1 Myrica salicifolia A. Rich. ...................................................................................................... 8 2.2.1.1 Botany ............................................................................................................................... 8 2.2.1.2 Ethnomedicinal uses ......................................................................................................... 9 2.2.1.3 Phytochemistry and biological activity ............................................................................... 10 2.2.2 Pappea capensis Eckl. & Zeyh. ............................................................................................ 10 2.2.2.1 Botany ............................................................................................................................. 10 2.2.2.2 Ethnomedicinal uses ....................................................................................................... 11 2.2.2.3 Phytochemistry and biological activity ........................................................................... 12 2.2.3 Flacourtia indica (Burm. f.) Merr. ....................................................................................... 13 2.2.3.1 Botany ............................................................................................................................. 13 2.2.3.2 Ethnomedicinal uses ......................................................................................................