Rubia tinctorum munjistin from

Fig. 2.147. UV (254) trace of a crude extract of Rubia tinctorum roots and mass spectra (single MS) of the chromatographic peaks for individual anthraquinones lucidin primeveroside (1), ruberythic acid (2), pseudopurpurin (5) and munjistin (6). Mass spectra (a-b) were obtained with NI-ESI with post-column addition of ammonia. Reprinted with permission from G. C. H. Derksen et al. [320].

After the first isolation of alizarin a lot of other anthraquinones were isolated from Rubia tinctorum for example purpurin, munjistin, rubiadin, pseudopurpurin, nordamnacanthal, lucidin, xanthopurpurin and anthra-gallol. 

Some anthraquinones isolated from Rubia tinctorum are believed to be artefacts for example the anthraquinones which show the presence of a 2-methoxymethyl or 2-ethoxymethyl group. These anthraquinones have been formed during the extraction of lucidin with boiling methanol or ethanol [4,68,97]. According to Schweppe the anthraquinones purpurin (1,2,4-trihydroxy anthraquinone) and purpuroxanthin (1,3-dihydroxy-anthaquinone) are formed from respectively pseudopurpurin (3-carboxy-1,2,4-trihydroxyanthraquinone) and munjistin (2-carboxy-l,3-dihydroxy-anthraquinone) during drying of the roots [3]. Some anthraquinones were only isolated once from Rubia tinctorum. It is thus doubtful whether these... 

Alizarin, Pseudopurpurin, Purpurin as well as Lucidin, Morindone, Munjistin and Rubiadin in Madder and other closely related dyestuffs of natural origin from plant species such as Rubia tinctorum L. and other R. species, Odenlandia species, Morinda species and Galium species. 

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