title: Mass-spectral identification and purification of phycoerythrobilin and phycocyanobilin.
abstract: The bile-pigment chromophores of C-phycoerythrin (phycoerythrobilin) and C-phycocyanin (phycocyanobilin) were cleaved from their respective proteins with boiling methanol or butan-1-ol. They were purified as dicarboxylic acids by preparative reverse-phase liquid chromatography. Each pigment existed in two principal forms, which were characterized by using 20 pmol samples by proton-transfer chemical-ionization mass spectroscopy. These two principal forms were isomeric species, and all had protonated parent molecular ions with m/e 587, corresponding to a molecular weight of 586.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D002853:Chromatography, Liquid; D007536:Isomerism; D013058:Mass Spectrometry; D008970:Molecular Weight; D052980:Phycobilins; D010798:Phycocyanin / Q000302:isolation & purification*; D010799:Phycoerythrin / Q000302:isolation & purification*; D010860:Pigments, Biological / Q000302:isolation & purification*; D011758:Pyrroles / Q000302:isolation & purification*
chemical_list: D052980:Phycobilins; D010860:Pigments, Biological; D011758:Pyrroles; D010798:Phycocyanin; D010799:Phycoerythrin; C011070:phycoerythrobilin; C011069:phycocyanobilin