Cerebrosides purification

Differences in nutritional effects between PLs and TAGs can be caused by several factors not related to their fatty acid composition, such as the presence of a phosphate group and a nitrogen base (mainly chohne) that may interact in several metabolic pathways (82). Moreover, several glycerophospholipid preparations studied can contain other components such as cholesterol, cerebrosides, sphingomyelins also depending on their source, method of isolation, and purification. These components may also affect the nutritional properties. In this chapter, the metabolic fate of constituent fatty acids of PLs and TAGs will be compared. 

Fischer, G., and Jatzkewitz, H., The activator of cerebroside sulphatase Purification from human liver and identification as a protein. Hoppe-Seyler s Z. Physiol. Chem. 356, 605-613 (1975). 

Applications of countercurrent distribution to lipid purification were already reported in the 1950s. These included the isolation of PC, SPM, or cerebrosides from brain tissue, or the placenta. It was then mentioned that lipids easily emulsify, and this adversely affects the ability to separate them. Therefore these methods were only used for crude separation. The method also requires a long time for phase separation before each phase transfer, and this procedure needs to be repeated 500-3000 times. Otsuka and Yamakawa reported the application of droplet CCC to the purification of phospholipids and glycohpids. Because the stationary phase retention is much more stable in TC-CCC than with HS-CCC, it has become possible to select appropriate two-phase solvent systems. In this study, we showed the successful separation of human brain lipids by using TC-CCC. Additionally, if an isolated band can be observed on HPTLC, the lipid can be purified by using silica column chromatography after TC-CCC cmde separation. 

The importance of reliable methods is illustrated by the example of determining the concentration of cerebrosides in plasma. By measuring the increase in reducing power of a serum lipid extract before and after hydrolysis which was believed to be due to sugar released from cerebrosides Kirk (1938) found concentrations between 0 and 167 mg per 100 ml. With the use of purification procedures and specific reactions for sugars Svennerholm and Svennerholm (1958) were able to demonstrate a mean cerebroside content of 4.36 0.18 mg per 100 ml of plasma. 

Bowen, D. M., and Radin, N. S., 1968a, Purification of cerebroside galactosidase from rat brain, Biochim. Biophys. Acta 152 587-598. 

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