Carissa Macrocarpa and Harpephyllum Caffrum
Total Page:16
File Type:pdf, Size:1020Kb
Phytochemical and Analytical Studies on Two Indigenous Medicinal Plants Found in KwaZulu-Natal, South Africa; Carissa macrocarpa and Harpephyllum caffrum ROSHILA MOODLEY 2012 i Phytochemical and Analytical Studies on Two Indigenous Medicinal Plants Found in KwaZulu- Natal; Carissa macrocarpa and Harpephyllum caffrum ROSHILA MOODLEY 2012 A thesis submitted to the School of Chemistry and Physics, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville, for the degree of Doctor of Philosophy. This thesis has been prepared according to Format 4 as outlined in the guidelines from the College of Agriculture, Engineering and Science which states: This is a thesis in which chapters are written as a set of discrete research papers, with an overall introduction and final discussion where one (or all) of the chapters have already been published. Typically, these chapters will have been published in internationally- recognized, peer- reviewed journals. As the candidate’s supervisor, I have approved this thesis for submission. Supervisor: Signed: --------------------------------Name: ------------------------- Date: -------------- ii ABSTRACT Vulnerable communities and rural households usually turn to natural resources for their nutritional and healthcare needs. However, very little is known about the nutritional and medicinal value of many plant species utilized by these communities despite widespread scientific research on medicinal plants. This is mainly due to the huge numbers of medicinal plants that are in use. This study aimed at investigating two plants species that are indigenous to KwaZulu-Natal and contain edible fruits namely Carissa macrocarpa and Harpephyllum caffrum, as a source of secondary metabolites and essential dietary elements, because of their claimed medicinal value and nutritional potential. The analytical results indicate that the fruits are a good source of essentiary dietary elements and can contribute to the recommended dietary allowances (RDAs) for most nutrients. Phytochemical analysis shows that the fruits of C. macrocarpa are rich in the pharmacologically active pentacyclic triterpenoids whose immune boosting properties are well-known. The fruits can therefore be consumed to boost the immune system in areas where immune boosting supplements are out of reach. The fruits of H. caffrum were found to be rich in the flavan- 3-ol antioxidant, (+)-catechin. The fruits can therefore be used as a substitute for antioxidant supplements taken in Western and European countries. This study lends scientific credence and validity to the ethnomedicinal use of these plants and reveals the nutritional and medicinal benefits of consuming the indigenous edible fruits. It also adds to the growing body of research on indigenous medicinal plants. iii SUMMARY OF ISOLATED COMPOUNDS A-1: R1=CH3; R2=H; R3=CH3 A-2: R1=C(O)OCH3; R2=H; R3=CH3 A-3: R1=COOH; R2=H; R3=CH3 A-4: R1=COOH; R2=CH3; R3=H iv v ABBREVIATIONS 13C NMR - C-13 nuclear magnetic resonance spectroscopy 1H NMR - proton nuclear magnetic resonance spectroscopy A - bioavailable ANOVA - analysis of variance BAF- bioaccumulation factor CEC- cation exchange capacity COSY - correlated spectroscopy CRM- Certified Reference Material d - doublet dd - double doublet DEPT - distortionless enhancement by polarization transfer DM- dry mass DPPH - 2,2-diphenyl-1-picrylhydrazyl DRI - Dietary Reference Intake EDTA- ethylenediamine tetraacetic acid Ex - exchangeable FRAP - ferric reducing antioxidant potential GC-MS - gas chromatography-mass spectrometry HMBC - heteronuclear multiple bond coherence HSQC - heteronuclear single quantum coherence Hz - Hertz ICP-OES- Inductively Coupled Plasma-Optical Emission Spectrometry vi IR - infrared MUFA- monounsaturated fatty acid NOESY - nuclear overhauser effect spectroscopy PUFA- polyunsaturated fatty acid r- correlation coefficient RDA- recommended dietary allowance SD - standard deviation SOM - soil organic matter T - total TLC - thin-layer chromatography UL- tolerable upper intake level UV - ultraviolet vii DECLARATIONS Declaration 1 - Plagiarism I, Roshila Moodley declare that 1. The research reported in this thesis, except where otherwise indicated, is my original research. 2. This thesis has not been submitted for any degree or examination at any other university. 3. This thesis does not contain other persons’ data, pictures, graphs or other information, unless specifically acknowledged as being sourced from other persons. 4. This thesis does not contain other persons' writing, unless specifically acknowledged as being sourced from other researchers. Where other written sources have been quoted, then: a. Their words have been re-written but the general information attributed to them has been referenced b.Where their exact words have been used, then their writing has been placed in italics and inside quotation marks, and referenced. 5. This thesis does not contain text, graphics or tables copied and pasted from the Internet, unless specifically acknowledged, and the source being detailed in the thesis and in the References sections. Signed ………………………………………………………… viii Declaration 2 – Publications Publication 1 Title: Elemental composition and fatty acid profile of the edible fruits of Amatungula (Carissa macrocarpa) and impact of soil quality on chemical characteristics. Authors: Roshila Moodley, Neil Koorbanally and Sreekanth B. Jonnalagadda. Journal: Analytica Chimica Acta, 2012, 730: 33-41. Publication 2 Title: Antibacterial and anti-adhesion activity of the pentacyclic triterpenoids isolated from the leaves and edible fruits of Carissa macrocarpa. Authors: Roshila Moodley, Hafizah Chenia, Sreekanth B. Jonnalagadda and Neil Koorbanally. Journal: Journal of Medicinal Plants Research. 2011, 5(19), 4851-4858. (Online). Publication 3 Title: Antioxidant activity of Phenolic compounds isolated from the edible fruits and stem bark of Harpephyllum caffrum. Authors: Roshila Moodley, Neil Koorbanally, Sreekanth B. Jonnalagadda and Md. Shahidul Islam. Journal: manuscript submitted to African Journal of Pharmacy and Pharmacology. Publication 4 Title: Elemental composition and nutritional value of the edible fruits of Harpephyllum caffrum and impact of soil quality on chemical characteristics Authors: Roshila Moodley, Neil Koorbanally and Sreekanth B. Jonnalagadda. Journal: manuscript accepted for publication: Journal of Environmental Science and Health. ix In all of the publications I have performed all the experimental work and written the manuscripts. The co-authors were involved in discussion of the results and were responsible for verifying the scientific content and accuracy of the results as well as editing the manuscripts. I have been the corresponding author on two of the manuscripts contained in this thesis. Signed: ………………………………….. x ACKNOWLEDGEMENTS Firstly, I would like to acknowledge God, the Almighty, for giving me the power to believe in myself and pursue my dream and for endowing me with health and knowledge to realise this dream. Secondly, my sincerest thanks and gratitude go to my supervisors, Prof. S.B. Jonnalagadda and Dr N. Koorbanally, who helped me conceptualize the topic and who inspired me to reach the successful completion of my PhD research. I am grateful to them both for sharing their expert knowledge and immense experience in research as well as assisting and guiding me with constructive criticism and invaluable suggestions. I would also like to acknowledge the College of Agriculture, Engineering and Science (UKZN), Dean and HOS, and DVC of Research (CAES) for affording me this opportunity. I would also like to acknowledge with thanks: My friends, Shakira Shaik, Joyce Bett and Dorothy Okoth for their love and support. The technical team in the School of Chemistry at UKZN (Westville) for their assistance, in particular Anita Naidoo, Neil Broomhead and Dilip Jagjivan. The postgraduates in the Natural Products Research Group and my postgraduate students for their friendly faces and warm smiles. My colleagues in the School of Chemistry and Physics and Access Programme for their moral support. xi Hafizah Chenia (Microbiology) and Auwal M. Ibrahim (Biochemistry) for their advice and training. My PhD journey would not have begun and surely not have ended without the continued love, support, and encouragement of my husband, Riza, and my mother who have been strong forces in all of my accomplishments. Thank you for always being there for me. Last but not least, I would like to thank my boys, Zia and Zubair, for their unconditional love, patience and understanding throughout my studies. I love you very much. xii Contents ABSTRACT ............................................................................................................. iii SUMMARY OF ISOLATED COMPOUNDS ......................................................... iv ABBREVIATIONS ................................................................................................... vi DECLARATIONS ................................................................................................. viii Declaration 1 - Plagiarism .................................................................................... viii Declaration 2 – Publications ..................................................................................... ix ACKNOWLEDGEMENTS...................................................................................... xi LIST OF TABLES .................................................................................................