i EFFECTS OF STRUCTURAL MODIFICATIONS OF TSETSE-REPELLANT δ- OCTALACTONE ON THE RESPONSES OF Glossina pallidipes and G. morsitans morsitans RONALD NYAKWEBA OTONDI (B.ed, Sc.) I56/20057/2012 A Thesis Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master (Science) in Chemistry in the School of Pure and Applied Sciences of Kenyatta University NOVEMBER, 2016 ii DECLARATION I hereby declare that this thesis is my original work and has not been presented for the award of any degree in any other university. Ronald Nyakweba Otondi I56/20057/2012 Signature…………………………..Date………………………………………………. SUPERVISORS We confirm that the work reported in this thesis was carried out by the candidate under our supervision as university supervisors. Dr. Margaret Ng’ang’a Department of Chemistry Kenyatta University Signature……………………………Date……………………………………………. Prof. Ahmed Hassanali Department of Chemistry Kenyatta University Signature…………………………… Date……………………………………………. iii DEDICATION I dedicate this work to my late aunt Trusillah Nyaburi, my grandparents Charles Makang’a and Grace Nyambori. My mother Loice Kerubo, my wife Everlyne Mogoi and my daughter Adrianna Nyaburi for their love, encouragement and immeasurable support that enabled me to complete my work. iv ACKNOWLEDGEMENTS I am grateful to the almighty God for granting me strength and good health with which I was able to carry out my research conclusively and successfully. I want to sincerely appreciate Kenyatta University Graduate School for granting me an opportunity to pursue my Masters degree. With profound gratitude and great humility, I appreciate Dr. Margaret Ng’ang’a and Prof. Ahmed Hassanali for agreeing to be my supervisors and providing scientific guidance throughout my Masters research. I am immensely thankful to Dr. Grace Mulira (Director) of Biotechnology Research Institute (BRI) for sponsoring my laboratory work and allowing me carry out tsetse flies behavioural studies in their laboratories with the assistance of Mr. Patrick Obore (Ttechnician). Their support and unyielding guidance immensely contributed to the success of the data collecting stage. I also wish to appreciate the financial support I obtained from my late aunt Trusilla nyaburi and my brother Benard Omache. I thank Mr. Godfrey Ndiangui of Kenyatta university science workshop for helping me to construct the wind tunnel. My sincere appreciation goes to my dear wife, Everlyne Mogoi, who was full of moral support and encouragement when I was far away in the laboratory collecting data so that I could succeed in this dignified task. v TABLE OF CONTENTS TITLE PAGE ....................................................................................................................... i DECLARATION ................................................................................................................ ii DEDICATION ................................................................................................................... iii ACKNOWLEDGEMENTS ............................................................................................... iv TABLE OF CONTENTS .....................................................................................................v LIST OF TABLES ............................................................................................................ vii LIST OF FIGURES ......................................................................................................... viii ABBREVIATIONS AND ACRONYMS .......................................................................... ix ABSTRACT .........................................................................................................................x CHAPTER ONE ................................................................................................................1 INTRODUCTION ...............................................................................................................1 1.1 Background information ................................................................................................1 1.2 African Trypanosomiasis ...............................................................................................2 1.2.1 The mammalian host ...................................................................................................2 1.2.2 Animal African Trypanosomiasis ...............................................................................3 1.2.2.1 Epidemiology of African Animal Trypanosomiasis ................................................5 1.2.2.2 Control of African animal Trypanosomiasis ............................................................6 1.2.3 Human African Trypanosomiasis ...............................................................................9 1.2.3.1 Epidemiology of Human African Trypanosomiasis ..............................................11 1.2.3.2 Control of Human African Trypanosomiasis .........................................................12 1.3 Tsetse fly distribution ..................................................................................................13 1.3.1 Tsetse fly distribution in Africa ................................................................................13 1.3.1.1 The distribution and habitat of Morsitans group ....................................................14 1.3.1.2 The distribution and habitat of Palpalis group .......................................................15 1.3.1.2 The distribution and habitat of Fusca group ..........................................................16 1.3.2 Tsetse fly distribution in Kenya ................................................................................17 1.4 Statement of the problem and justification ..................................................................22 1.5 Hypothesis....................................................................................................................23 1.6 Objectives ....................................................................................................................23 1.6.1 General objective ......................................................................................................23 1.6.2 Specific objectives ....................................................................................................23 1.7 Scope and limitation of the study.................................................................................23 1.8 Significance of the study ..............................................................................................24 CHAPTER TWO .............................................................................................................25 LITERATURE REVIEW ..................................................................................................25 2.1 Tsetse fly vector ...........................................................................................................25 2.1.1 The Life Cycle of tsetse fly .......................................................................................25 2.1.2 Methods of tsetse fly control.....................................................................................27 2.2 Semiochemicals and blood-feeding insects. ................................................................32 2.3 Host location by tsetse fly ............................................................................................33 2.4 Non-host odor repellant to tsetse fly. ...........................................................................35 2.5 Repellent properties of δ-octalactone ..........................................................................37 2.6 Structure-repellency studies of δ-octalactone ..............................................................38 vi CHAPTER THREE .........................................................................................................40 MATERIALS AND METHODS .......................................................................................40 3.1 Test compounds and blends .........................................................................................40 3.2. Syntheses of targeted δ-octalactone analogues ...........................................................41 3.2.1 Synthesis of (RS)-3-propylcyclohexanone (15) ........................................................41 3.2.2 Synthesis of (RS)-δ-valerolactone (16) .....................................................................42 3.3 Tsetse flies ...................................................................................................................44 3.4 The wind-tunnel ...........................................................................................................44 3.4.1 Odour dispensers .......................................................................................................45 3.5 Experimental procedure for the tsetse behavioral responses .......................................46 3.6 Statistical analyses .......................................................................................................48 CHAPTER FOUR ............................................................................................................49 RESULTS AND DISCUSSION ........................................................................................49 4.1 Syntheses and structure confirmation of targeted δ-octalactone analogues ................49 4.2 Behavioural response of G. pallidipes to δ-octalactone analogues and blends