Allose rates

Figure 20 Post-column detection of mono- and disaccharides with 4-amino-benzoylbenzamide. Column CarboPac PA-1. Gradient 1-10 mm NaOH (0-20 min.), 10-20 mM NaOH (20-35 min). Flow rate 1 ml/min. Detection absorbance at 400 nm after reaction with 4-aminobenzoylhydrazide. (a) Standard mixture of fucose (1), arabinose (2), galactose (3), glucose (4), xylose and N-acetylglucosamine (5 and 6), allose (7), 3-fucosyllactose (8), fructose (9), lactose (10), Man-(3-(l,4)-GlcNac. (b) Normal urine, (c) Urine from a child with (3-mannosidosis. (Reproduced with permission of Academic Press from Peelen, G. O. H., de Jong, J. G. N., and Wever, R. A., Anal. Biochem., 198, 334, 1991.)...

Fig. 4.—Rates of Consumption13 of Lead Tetraacetate by Some Aldoses (1) D-Mannose, (2) i.-Rhamnose, (3) D-Altrose, (4) D-Allose, (5) D-Galactose, and (6) D-Glucose (Temp. 0°).

Lemieux and Brice have measured the rate of exchange (in chloroform) of a large number of 1,2-trans sugar acetates with stannic trichloride acetate labeled with C. Their results are given in Table XVII. The low reactivities of the acetates of 8-D-ribose, a-D-lyxose, 8-D-allose, and a-D-mannose (rela-... 

Various sugars epimerize at different rates. For example, maimose is converted much slower than glucose or fructose [9] and it is also formed more slowly. Idose reacts very rapidly in the presence of bases, altrose rapidly but allose slowly [23]. The most investigated case is, of course, the glucose-maimose-fruc-tose system. The products are formed in a ratio of approximately 4 1 4. More accurate figures have been quoted but the composition will depend on the nature of the base and of the starting material True equilibrium, as already stated, is probably never obtained [9]. 

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