Ford, L, Rayner, CM orcid.org/0000-0003-1091-081X and Blackburn, RS orcid.org/0000-0001-6259-3807 (2018) Degradation of lucidin: New insights into the fate of this natural pigment present in Dyer's madder (Rubia tinctorum L.) during the extraction of textile artefacts. Dyes and Pigments, 154. pp. 290-295. ISSN 0143-7208
Abstract
The complex mixtures of colorants present in different madder species can provide significant information about which plant species or technique was used to dye the fibres of historical textile artefacts, hence, when extracting and analysing colorants from textile artefacts as much of this information as possible should be preserved. Historical textiles are most commonly extracted with 37% hydrochloric acid: methanol: water (2:1:1, v/v/v), but this solvent system hydrolyses dye glycosides and may also induce chemical reactions. One of the primary components in Dyers' madder (Rubia tinctorum L.) is lucidin primeveroside, but it is rarely seen in artefacts, nor is the corresponding aglycon lucidin. It has been demonstrated that the hydrochloric acid method causes hydrolysis of anthraquinone glycosides to their aglycon counterpart. Herein it is demonstrated that lucidin is not stable in such acidic conditions and degrades rapidly to xanthopurpurin. This is confirmed by HPLC, LC-MS and 1H NMR, which also provide evidence of the mechanism of degradation being a retro-aldol process.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2018 Elsevier Ltd. All rights reserved. This is an author produced version of a paper published in Dyes and Pigments. Uploaded in accordance with the publisher's self-archiving policy |
Keywords: | Madder; Rubia tinctorum; lucidin; dyes; textiles; extraction; reactivity; HPLC analysis |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Organic Chemistry (Leeds) The University of Leeds > Faculty of Arts, Humanities and Cultures (Leeds) > School of Design (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Mar 2018 17:05 |
Last Modified: | 14 Mar 2019 01:39 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.dyepig.2018.03.023 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:128499 |