TECHNISCHE UNIVERSITÄT MÜNCHEN
Lehrstuhl für Chemisch-Technische Analyse und Chemische Lebensmitteltechnologie
Enrichment of Biologically Active Compounds from Selected
Plants Using Adsorptive Bubble Separation
Leonor Thompson
Vollständiger Abdruck der von der Fakultät Wissenschaftszentrum Weihenstephan für
Ernährung, Landnutzung und Umwelt der Technische Universität München zur Erlangung des akademischen Grades eines
Doktors der Naturwissenschaften (Dr. rer. nat.)
genehmigten Dissertation.
- Vorsitzender:
- Univ.-Prof. Dr. K. Sommer
1. Univ.-Prof. Dr. H. Parlar 2. Univ.-Prof. Dr. K.-H. Engel
Prüfer der Dissertation: Die Dissertation wurde am 16.06.2004 bei der Technischen Universität München eingereicht und durch die Fakultät Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt am 22.09.2004 angenommen.
Dedicated to the memory of my late father, for instilling in me the desire to learn and the praise for the good values of Life
Acknowledgements
The research work presented in this PhD thesis was realised at the Chair for Chemical and Technical Analysis and Chemical Food Technology of the Technical University of Munich, in Freising, Weihenstephan. I would like to express my gratitude to:
Prof. Dr. Harun Parlar, the Head of the Chair and my supervisor, for providing me with an interesting topic for the thesis, for the freedom to implement my ideas and the availability of funds for the financing of three years of work.
Dr. Mehmet Coelhan, the head of my working group, for providing that the required means for the pursuance of my work were met, for the practical hints, particularly in relation with the HPLC and GC-MS analysis, as well as the interesting discussions regarding chemistry.
Ms. Florence Beaume, for the good atmosphere in the laboratory, the interesting discussions on chemistry and themes other than science, for a great companionship during the time of hard work and sporadic pleasant breaks.
Dr. Carsten Wattenbach, for the help given with the NMR analysis and the readiness for the innumerable and challenging discussions concerning chemistry.
Mr. Albrecht Friess, for the kind, untiring and timely help in the improvement of the linguistics and presentation aspects of this thesis, as well as for sorting out administrative details of the thesis.
Mr. Kurt Sholz, for the prompt production of special glass apparatus for the Foam Fractionation.
Ms. Johanna Strohmeier, for the good atmosphere in the laboratory and companionship. Ms. Bettina Zimmerman, for the help with the GC-ECNI/MS analysis. Ms. Mareike Wenning from the Microbial Ecology Group, Technical University of Munich, for the help with the FTIR analysis.
Prof. Dr. Matthias Hamburger, Friedrich-Schiller University, Jena, for the kind supply of the tryptanthrin standard. The Raps Institute in Freising, Weihenstephan, the Thuringian State Institute for Agriculture, Thuringia and the firma BAFA, Malsch, for the kind supply of plant raw materials.
I finally express my deepest gratitude to my wonderful family to whom I owe so much: My mother Mrs. Lucia Thompson, for the support, encouragement, caring and for being a source of strength during the difficult moments. My siblings, in particular Prof. Dr. Rachael Thompson, Prof. Dr. Gertrude Thompson and Dr. Ricardo Thompson, for the support, encouragement, and wise advice.
My husband Dr. Michael Lutze, for helping with the linguistic improvement of this thesis, for always standing by me both for the happy and difficult moments, for the understanding, encouragement and loving. My small daughter Michelle Thompson Lutze, for being such a lovely child, a source of inspiration and for her contagious joy. Contents
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Contents
1. INTRODUCTION------------------------------------------------------------------------------ 1 2. THEORETICAL BACKGROUND ---------------------------------------------------- 5 2.1 Non-Foaming Adsorptive Bubble Separation and Foam Separation ------------------- 6 2.2 Foam Fractionation ------------------------------------------------------------------------------- 7
2.2.1 Adsorption ------------------------------------------------------------------------------------- 8 2.2.2 Foams ------------------------------------------------------------------------------------------13
2.2.2.2 Drainage and Thinning ---------------------------------------------------------------15 2.2.2.3 Gas Diffusion Coalescence and Bubble size---------------------------------------16 2.2.3.1 Foam Fractionation Devices ---------------------------------------------------------17
2.2.4 Efficiency of Foam Fractionation --------------------------------------------------------20 2.2.5 Parameters Influencing the Efficiency of Foam Fractionation---------------------22
2.2.5.1 Concentration of Solute and Surfactant-------------------------------------------22 2.2.5.2 Addition of Organic Solvents --------------------------------------------------------22 2.2.5.3 Addition of Electrolytes and Polyelectrolytes ------------------------------------23 2.2.5.4 Addition of Viscosity Enhancers ----------------------------------------------------23 2.2.5.5 pH of Solution---------------------------------------------------------------------------24 2.2.5.6 Ionic Strength---------------------------------------------------------------------------24 2.2.5.7 Gas Flow Rate --------------------------------------------------------------------------24 2.2.5.8 Height of Liquid Pool------------------------------------------------------------------25 2.2.5.9 Height of Foam Tower ----------------------------------------------------------------25 2.2.5.10 Internal Reflux Ratio ----------------------------------------------------------------25
2.3 Plant Materials Under Investigation----------------------------------------------------------26
2.3.1 Calendula Officinalis L. --------------------------------------------------------------------27
2.3.1.1 General-----------------------------------------------------------------------------------27 2.3.1.2 Chemical Composition ----------------------------------------------------------------28 2.3.1.3 Active Principles------------------------------------------------------------------------29 2.3.1.4 Other Components---------------------------------------------------------------------33 2.3.1.5 Biological and Pharmacological Activity ------------------------------------------34 2.3.1.6 Toxicology -------------------------------------------------------------------------------34
Contents
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2.3.2 Camellia Sinensis L.-------------------------------------------------------------------------35
2.3.2.1 General-----------------------------------------------------------------------------------35 2.3.2.2 Chemical Composition ----------------------------------------------------------------36 2.3.2.3 Active Principle-------------------------------------------------------------------------36 2.3.2.4 Other compounds ----------------------------------------------------------------------39
2.3.3 Isatis Tinctoria L. ----------------------------------------------------------------------------44
2.3.3.1 General-----------------------------------------------------------------------------------44 2.3.3.2 Chemical Composition ----------------------------------------------------------------45 2.3.3.3 Active Principle-------------------------------------------------------------------------45 2.3.3.5 Important Conversions of the Main Components -------------------------------46 2.3.3.6 Biological and Pharmacological Activity ------------------------------------------47 2.3.3.7 Toxicity-----------------------------------------------------------------------------------47
2.3.4 Cannabis Sativa L. --------------------------------------------------------------------------48
2.3.4.1 General-----------------------------------------------------------------------------------48 2.3.4.2 Chemical Composition ----------------------------------------------------------------49 2.3.4.3 Active Principle-------------------------------------------------------------------------50 2.3.4.4 Other components----------------------------------------------------------------------52 2.3.4.5 Important Reactions of Active Cannabinoids ------------------------------------52 2.3.4.6 Biological and Pharmacological Activity ------------------------------------------53 2.3.4.7 Toxicology -------------------------------------------------------------------------------54
3. MATERIALS EQUIPMENTS AND METHODS -------------------------------------------55 3.1 Materials -------------------------------------------------------------------------------------------55
3.1.1 Samples of Plant Materials ----------------------------------------------------------------55 3.1.2 Standards -------------------------------------------------------------------------------------56 3.1.3 Chemicals and Solvents--------------------------------------------------------------------58 3.1.4 Miscellaneous Materials--------------------------------------------------------------------59
3.2 Foam Fractionation Unit and Equipments --------------------------------------------------59
3.2.1 Foam Fractionation Unit-------------------------------------------------------------------59 3.2.2 High Performance Liquid Chromatography ------------------------------------------60 3.2.3 Gas Chromatography ----------------------------------------------------------------------61 3.2.3 UV-Vis Spectroscopy -----------------------------------------------------------------------61 3.2.4 Nuclear Magnetic Resonance Spectroscopy--------------------------------------------61
Contents
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3.2.5 Fourier Transform Infrared Microspectroscopy -------------------------------------61 3.2.6 Other Equipments---------------------------------------------------------------------------62
3.3 Methods---------------------------------------------------------------------------------------------62
3.3.1 Analytical Characterisation and Quantification --------------------------------------62
3.3.1.1 Faradiol Esters--------------------------------------------------------------------------62 3.3.1.2 Catechins---------------------------------------------------------------------------------64 3.3.1.3 Tryptanthrin ----------------------------------------------------------------------------65 3.3.1.4 Cannabinoids ---------------------------------------------------------------------------66
3.3.2 Extraction-------------------------------------------------------------------------------------67
3.3.2.1 Extraction of Faradiol Esters -------------------------------------------------------67 3.3.2.2 Extraction of Catechins ---------------------------------------------------------------68 3.3.2.3 Extraction of Tryptanthrin-----------------------------------------------------------68 3.3.2.4 Extraction of Cannabinoids----------------------------------------------------------68
3.3.3 Foam Fractionation -------------------------------------------------------------------------69
3.3.3.1 Foam Fractionation of Faradiol Esters---------------------------------------------70 3.3.3.2 Foam Fractionation of Catechins ---------------------------------------------------74 3.3.3.3 Foam Fractionation of Tryptanthrin-----------------------------------------------76
4. RESULTS-----------------------------------------------------------------------------------------82 4.1 Accuracy of Measurements and Quantification of Active Principles by HPLC -----82 4.2 Calendula Officinalis------------------------------------------------------------------------------85
4.2.1 Analytical Characterisation of Lupeol Acetate ---------------------------------------85
4.2.1.1 UV-Vis Characterisation -------------------------------------------------------------85
4.2.1.2 HRGC-EI/MS Characterisation -------------------------------------------------------85 4.2.2 Extraction of Faradiol Esters -------------------------------------------------------------86 4.2.3 Enrichment of Faradiol Esters-----------------------------------------------------------87
4.2.3.1 Influence of Surfactant and Additives ---------------------------------------------88 4.2.3.2 Influence of Solute Concentration and pH----------------------------------------89 4.2.3.3 Influence of Height of Foam Tower and Height of Liquid Pool --------------91 4.2.3.4 Influence of Time of Foaming and Gas Flow Rates -----------------------------92 4.2.3.5 Optimised Overall Enrichment Process -------------------------------------------93
4.3 Camellia Sinensis----------------------------------------------------------------------------------95
Contents
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4.3.1 Analytical Characterisation of Catechins ----------------------------------------------95
4.3.1.1 UV-Vis Characterisation -------------------------------------------------------------95 4.3.1.2 Nuclear Magnetic Resonance Characterisation ---------------------------------96
4.3.2 Extraction of Catechins --------------------------------------------------------------------96 4.3.3 Enrichment of Catechins-------------------------------------------------------------------97
4.3.3.1 Influence of Solute Concentration, Additives and pH ---------------------------98 4.3.3.2 Influence of Consecutive Foaming and Gas Flow Rate----------------------- 100 4.3.3.3 Optimised Overall Enrichment Process ----------------------------------------- 101