Separation and identification of the carotenoid pigments of stigmata isolated from light-grown cells of Euglena gracilis strain Z.

Thin layer chromatography of the carotenoid pigments of stigmata isolated from light grown cells of Euglena gracilis strain Z resolved 29 compounds, of which 16 could be eluted and their absorption spectra recorded. Seven of these compounds were identified by a combination of co-chromatography with authentic compounds and by chemical tests, one of these compounds (beta-carotene) was further identified by mass spectrometry. The major carotenoids were found to be beta-carotene, diatoxanthin and diadinoxanthin which together comprised approximately 60% of the stigma pigments. In addition significant quantities of canthaxanthin, echinenone and cryptoxanthin were isolated and a possible carotenoid ester was detected. The results of this analysis are compared with those of previous workers and the significance of the findings is discussed.