Betalains purification

Girod, P.-A. and Zryd, J.-P. (1991) Biogenesis of betalains purification and partial characterization of Dopa 4,5-dioxygenase from Amanitamuscaria. Phytochemistry, 30,169-74. 

To ensure maximum pigment retention, the acidic eluates should be checked for their pH values and if required, aqueous ammonia has been proven viable for pH adjustment to reach 5 to 7 pH values. While Sephadex G types were used in earlier studies for purification and desalting, Sephadex LH-20 is the material of choice today. Since the betalains will elute with water, it is doubtful whether effective salt removal is possible. However, Sephadex LH-20 has proven excellent for removing... 

Progress in the chemistry of betacyanins depended on the development of efficient methods for their isolation and separation. Betalains often occur as complex mixtures and are easily decomposed during the purification steps, which render the isolation of larger amounts of material for structural studies difficult. It is therefore understandable that some of the compounds described during the 1960s need reinvestigation by modem techniques. 

Betalain pigments in plants often were confused with an-thocyanins until a number of investigators in the late 19th century recognized that betacyanins contain nitrogen. However, purification of these pigments was difficult and, despite study by many well-known chemists, betalains were not fully characterized until 1963 (Wyler et al., 1963). The be-taxanthin, indicaxanthin (51), was characterized a year later (Fig. 37.14) (Piatelli et al, 1964). 

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