Chemical Analysis and Elucidation of Anthraquinone and Flavonoid Type Compounds with Applications to Historical Artefacts and Sustainability Lauren Louise Ford Submitted in accordance with the requirements for the degree of Doctor of Philosophy The University of Leeds School of Design School of Chemistry April 2017 i The candidate confirms that the work submitted is her own, except where work has formed part of jointly-authored publications has been included. The contribution of the candidate and the other authors of this work has been explicitly indicated below. The candidate confirms that appropriate credit has been given within the thesis where reference has been made to the work of others. Section 3.3 contains work from a jointly authored publication. In this work, the NMR experiments and synthesis of the reference material is directly attributed to the author of this thesis. The HPLC analysis and purification of the compounds is attributed to Jose Rodriguez, as referenced in the thesis text. This copy has been supplied on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. © 2017 The University of Leeds and Lauren Louise Ford The right of Lauren Louise Ford to be identified as Author of this work has been asserted by her in accordance with the Copyright, Designs and Patents Act 1988. i Acknowledgements I would like to thank Dr. Richard Blackburn and Prof. Chris Rayner for their support throughout the PhD programme and for no question ever being too silly (except on a few occasions). I am hugely grateful to the Clothworkers’ Company for providing the funding to undertake this research and for their continuous interest in the results provided. All of the technicians in the department of chemistry have been super helpful and always happy to help, so I would like to thank Martin Huscroft and Simon Barratt. I would also like to thank Dr. Chris Pask on his expert knowledge in crystal structure elucidation. I would also like to thank Dr. Meryem Benohoud for her extensive knowledge of chemistry and her patience in helping me to develop mine. I would also like to thank her for her moral support and friendship throughout the 3 year course and for all of the tea break chats which helped us to keep motivated. Both the Blackburn and Rayner groups, present and past members, deserve acknowledgement for their help with using equipment or listening to my talks and always providing feedback. I would also like to say a huge thank you to my friends and family for always being there for me and bringing me up if I have ever been down. Especially to my mum and dad who have given me the best start in life and always made me believe I am capable of anything. They have given me everything I could ever want and continue to support me unconditionally for which I will always be grateful. I would like to also thank Aisling and Alice for struggling through both undergraduate and PhD with me and putting up with my constant moaning. ii Abstract This thesis describes the effects of different solvents have on the extraction profile of natural dyes from dye plants: madder, weld, golden rod, and chamomile. HPLC has been used to build a fingerprint of each dye plant profile and thus used to compare to the profiles of back extraction from textiles for natural dye identification in historical artefacts. The use of solid phase extraction is compared to extraction methods with no purification step which is favourable for anthraquinone dyes but results in a major loss of glycosidic compounds when using yellow dyestuffs. Supported by 1H and 13C NMR data, the conclusive X-ray crystal structure of the natural dye ruberythric acid is presented which has never been achieved prior to this research. In a collaboration with food science two of the main components of chamomile are fully characterised by 1D and 2D, 1H and 13C NMR. These compounds are usually referred to as ferulic acid derivatives in the literature but their actual structure is reported herein. The thesis also discusses the relative dye uptake of anthraquinone compounds onto wool textiles which were measured by HPLC. Sorption isotherms for the main anthraquinones in madder; ruberythric acid, pseudopurpurin and alizarin are compared for more in-depth understanding on the method of adsorption of these compounds. Herein the glycosidic compounds in madder are shown to have a higher adsorption capacity than the aglycons. Ruberythric acid is shown to follow a Tempkin isotherm with the highest degree of correlation but both alizarin and ruberythric acid show good fitting with the Freundlich isotherm also. Pseudopurpurin was shown to follow a Freundlich isotherm with the highest degree of linearity but did also show some fitting to the Langmuir isotherm. The isotherms allow data to be collected on the energy of adsorption and draw conclusions on the effect the functional groups have on the dyeing capability which is studied herein for the first time on individual anthraquinone components. iii Studies were carried out on the acid-sensitive colorants present in madder which are degraded in the textile back extraction process. Anthraquinone aglycons alizarin and purpurin are usually identified in analysis following harsh back extraction methods, such as those using solvent mixtures with concentrated hydrochloric acid at high temperatures. Herein, a softer novel extraction method involving aqueous glucose solution was developed and compared to other back extraction techniques on wool dyed with root extract from different varieties of Rubia tinctorum. A study into the breakdown compounds of the aglycon; lucidin under acidic conditions used for traditional back extractions was also undertaken. Here it is observed that lucidin is converted into xanthopurpurin in a retro aldol like mechanism. This report discusses some of the issues raised by using these harsh back extraction methods and the problems faced in using them to analyse historic artefacts. iv Table of Contents Acknowledgements ........................................................................................................ ii Abstract ........................................................................................................................... iii Table of Contents ............................................................................................................ v List of Figures ................................................................................................................ ix List of Tables ............................................................................................................... xvii List of Schemes............................................................................................................ xix 1 Introduction .............................................................................................................. 1 1.1 History of Madder ................................................................................................ 3 1.2 History of Yellow textile colorants ........................................................................ 8 1.3 Cultivation, Harvesting and Processing of Dye Plants ........................................... 12 1.4 Compounds in Madder ....................................................................................... 14 1.5 Compounds in Yellow dye plants ........................................................................ 21 1.6 Extraction Isolation and Purification ................................................................... 23 1.7 Dyeing with Mordant Dyes ................................................................................. 25 1.8 Analysis of Compounds in Dye Plants .................................................................. 31 1.9 Back Extraction of Historical Textiles ................................................................... 37 1.10 Aims of Research ................................................................................................ 40 2 Extractions of Madder ........................................................................................... 42 2.1 Extraction of different madder varieties .............................................................. 46 2.1.1 Extraction of Iranian madder............................................................................... 49 2.1.2 Extraction of Turkish madder .............................................................................. 56 2.1.3 Extraction of English madder............................................................................... 59 v 2.2 Aqueous extractions of madder followed by Solid Phase Extraction (SPE) ............ 62 2.2.1 Extraction of Iranian madder with SPE ................................................................ 63 2.2.2 Extraction of Turkish madder with SPE ............................................................... 69 2.2.3 Extraction of English madder with SPE ................................................................ 71 2.3 Crystal structure elucidation of ruberythric acid .................................................. 74 2.4 Conclusions ........................................................................................................ 80 3 Extraction of yellow dyes ..................................................................................... 83 3.1 Ethanol extraction of yellow dye plants .............................................................. 86 3.1.1 Weld