Studies on red pigments excreted by cells of Chlorella protothecoides during the process of bleaching induced by glucose or acetate I. Chemical properties of the red pigments

During the process of bleaching of Chlorella protothecoidescells induced by the addition of glucose or acetate in a nitrogen-deficientmineral nutrient medium, at least four red pigments were foundto be excreted into the incubation medium. These pigments wereseparated by thin-layer chromatography on silica gel, and theirabsorption spectra in visible and infrared regions as well astheir NMR spectra were measured. Elementary composition andthe Gmelin colour reaction of the pigments were also examined.The results obtained suggest that the four pigments are certainacidic substances—containing a structure similar to thatof a bile pigment—which are most probably derived fromchlorophyll through oxidative rupture of the tetrapyrrole ringof the latter. (Received July 23, 1968; )