Flavylium chromophores as species markers for dragon's blood resins from Dracaena and Daemonorops trees.
A simple and rapid liquid chromatographic method with diode-array UV-vis spectrophotometric detection has been developed for the authentication of dragon's blood resins from Dracaena and Daemonorops trees. Using this method it was discovered that the flavylium chromophores, which contribute to the red colour of these resins, differ among the species and could be used as markers to differentiate among species. A study of parameters, such as time of extraction, proportion of MeOH and pH, was undertaken to optimise the extraction of the flavyliums. This method was then used to make extracts from samples of dragon's blood resin obtained from material of known provenance. From the samples analysed 7,6-dihydroxy-5-methoxyflavylium (dracorhodin), 7,4'-dihydroxy-5-methoxyflavylium (dracoflavylium) and 7,4'-dihydroxyflavylium were selected as species markers for Daemonorops spp., Dracaena draco and Dracaena cinnabari, respectively. The chromatograms from these samples were used to build an HPLC-DAD database. The ability to discriminate among species of dragon's blood using the single marker compounds was compared with a principal components analysis of the chromatograms in the HPLC-DAD database. The results from the HPLC-DAD method based on the presence of these flavylium markers was unequivocal. The HPLC-DAD method was subsequently applied to 37 samples of dragon blood resins from the historical samples in the Economic Botany Collection, Royal Botanic Gardens, Kew. The method identified anomalies in how samples in this collection had been labelled. It is clear that the method can be used to evaluate the provenance of samples used in different areas of cultural heritage. It also could be used to monitor the trade of endangered species of dragon's blood and the species being used in complex formulations of traditional Chinese medicine.
Sousa
Micaela M
MM
Department of Conservation and Restoration, Faculty of Sciences and Technology, New University of Lisbon, 2829-516 Monte da Caparica, Portugal.
Melo
Maria J
MJ
Parola
A Jorge
AJ
Seixas de Melo
J Sérgio
JS
Catarino
Fernando
F
Pina
Fernando
F
Cook
Frances E M
FE
Simmonds
Monique S J
MS
Lopes
João A
JA
D028023:Arecaceae / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D031409:Dracaena / Q000737:chemistry*; D010860:Pigments, Biological / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
D010860:Pigments, Biological; D010936:Plant Extracts; C525191:dragon's blood