Quantitative analysis of indigo and indigo precursors in leaves of Isatis spp. and Polygonum tinctorium.
Analysis of extracts from two woad species (Isatis tinctoria and Isatis indigotica) and Polygonum tinctorium revealed that only one indigo precursor (indican) was present in Polygonum, but two precursors were found in Isatis spp. This was done using high performance liquid chromatography (HPLC), coupled to an evaporative light scattering detector (ELSD). In Isatis spp., the indigo precursors indican and a fraction representing isatan B were identified. The proportion of indican and isatan B was different between the two Isatis spp. tested. For the first time, it was possible to quantify the precursors in woad plant species, and the results were found to be in good agreement with those made from total indigo quantification using two different spectrophotometric methods or a derivatization technique.
Gilbert
Kerry G
KG
School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK. k.g.gilbert@bristol.ac.uk
Maule
Hamish G
HG
Rudolph
Bernd
B
Lewis
Mervyn
M
Vandenburg
Harold
H
Sales
Ester
E
Tozzi
Sabrina
S
Cooke
David T
DT
D002851:Chromatography, High Pressure Liquid; D007203:Indigo Carmine; D007211:Indoles / Q000032:analysis*; D031219:Isatis / Q000737:chemistry*; D008027:Light; D013058:Mass Spectrometry; D018515:Plant Leaves / Q000737:chemistry*; D028502:Polygonum / Q000737:chemistry*; D012015:Reference Standards; D012542:Scattering, Radiation
D007211:Indoles; D007203:Indigo Carmine