Epimerization of glucose

To neutralize the hydrolysis products the solution is passed through a column (of about 15-cm length and 1-cm width) packed with an anion exchanger (e.g.,anion exchanger from Example 5-10). Neutralization with alkaline earth metal carbonates is to be avoided at all costs, in order to prevent epimerization of glucose to mannose which is favored by complex formation between mannose and alkaline earth metal ions. 

Mechanism 23-2 Base-Catalyzed Epimerization of Glucose 1115 Mechanism 23-3 Base-Catalyzed Enediol Rearrangement 1115 23-9 Reduction of Monosaccharides 1116... 

Base-Catalyzed Epimerization of Glucose 1115 Base-Catalyzed Enediol Rearrangement 1115... 

X Although the lactose in dairy prod-ucts is a major source of galactose, the ingestion of lactose is not required for lactation. UDP-galactose in the mammary gland is derived principally from the epimerization of glucose. Dairy products are, however, a major dietary source of Ca +, so breastfeeding mothers need increased Ca + from another source. 

Table 2. vatives Epimerization of glucose and mannose by nickel complexes of ethylenediamine deri- ... 

Table 6. Epimerization of glucose and mannose at various temperatures using racemic and optically active diamine ligands...

Figure 8 shows that the epimerization of glucose at 0 °C employing chxn with (R,R) configuration was found to give a better yield of the mannose epimer, although a longer time was required to reach equilibrium. When the epimerization reaction was performed with the (S,S)-isomer, a smaller proportion of man-... 

The variation of the epimerization in aqueous media was also studied. The catalytic activity was presented by means of relative activity with changing molar ratio between glucose and nickel complex. The epimerization of glucose under the normal conditions was employed as a standard. The results are summarized in Fig. 16. 

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