CS214431B1 - The process of preparing D-mannos - Google Patents

Abstract

The invention relates to a method for preparing D-mannose from an epimerization mixture of D-glucose. The essence of the invention lies in the fact that from a mixture of D-mannose and D-glucose, D-mannose, after reaction with aniline, is selectively bound in the form of crystalline N-phenyl mannosylamine, from which D-mannose is released by hydrolysis and aniline is removed by steam distillation.

Description

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The present invention relates to a process for preparing D-mannose from an epimerizing mixture of D-glucose. D-mannose is prepared by hydrolysis of mannans from Phytelephae macrocar-pa - R. Rieass Ber. 22, 609, (1889), from Porthyra umbilicalls algae - C.S. Hudson, E. L. J. Jackson; Am.Chem. Soe. 56. 958, (1944), the cell walls of yeast Saccharomycescerevislae - J. shandula, A. Vojtkova; Folia Mlcrobiol. 19, 94, (1974), or oxidation of mannitol B, Fischer, J. Hirschberger; Ber. 21, 1805, (1889). V, Bilik CSL. No. 149051 discloses the preparation of D-mannos by epimerizing D-glucose under the catalytic effect of molybdenum, wherein the D-glucose is partially removed from the epiridization mixture by crystallization and then D-rane is isolated as phenylhydrazone. Preparations of D-mannos by the hydrolysis of mannans or by the oxidation of mannitol are very difficult and require special raw materials or enzymes. Preparation of D-mannose by epimerization of D-glucose is simpler, but the disadvantage of this is the isolation of D-mannose through its phenylhydrazone. The process of preparing D-mannose becomes complicated, demanding, and can be carried out on a commercial scale. The proposed process for the preparation of D-mannose from the isomerization mixture through N-phenyl manozylamine is substantially simpler compared to the said methods of preparation.

SUMMARY OF THE INVENTION The invention is based on the fact that it selectively binds from the mixture of D -, - Lukozy and D - mannose, in the form of crystalline N - phenyl manozylamine, from which D - mannose is liberated by hydrolysis and the aniline is removed by steam distillation. The advantage of the proposed method of preparing D-mannos is that the raw materials are regenerated, thereby making the production process less expensive and preventing the environment from being polluted, the equipment required is simple and the chemicals commonly available, allowing the handling of harmful substances, provides the preparation of a high purity product. Example 1

An aqueous solution of 30% D-glucose and (0.06%) molybdenic acid solution is heated at 90 ° C for 2 hours. The solution is cooled and deionized on a column packed with an SBW aAc ion exchanger. The percolated solution is precipitated by the addition of concentrated acetic acid (0.4%), absolute ethanol (5%) and aniline (6.5%). The crystallization of N-phenyl mannosylamine is instantaneous, supported by mixing and cooling. The crystalline N-phenyl manozylamine is filtered on a suction filter and washed with cold water. Example 2

Decomposition of N-phenyl manozylamine

The aqueous suspension (10%) of N-phenyl manozylamine is distilled by steam to complete the elimination of the aniline. The resulting D-mannose solution was decolorized with charcoal, filtered on a vacuum rotary evaporator and concentrated to a thick syrup. The crystallization is carried out from absolute ethanol U5. Crystalline D-mannose is obtained in a 20% yield calculated as the flood raw material.

The invention has extensive use in the study of biochemical processes in living matter and in the living environment

Claims (1)

2 214 431 practitioner life in medicine and food industry industry. Although the method of preparing D-mannose from its epimerization mixtures is characterized in that aa D · aelectively binds aniline in the form of crystalline N-phenyl manozylamine, from which aaD-mannose is released by hydrolysis and aniline is removed by aqueous dehydration. steam. manoza