CS231545B1 - A method of preparing D-psicosis - Google Patents

Abstract

The invention relates to a method for preparing D-psicose. The essence of the invention lies in the fact that D-fructose is isomerized in an aqueous medium using a strong basic ion exchanger in hydroxide form at temperatures of 80 to 100 ° C for 8 to 12 h, where a suitable equilibrium mixture of sugars D-glucose, D-mannose, D-fructose and D-psicose is formed. This is selectively separated using a strong acidic cation exchanger in calcium form. A 40 to 60% aqueous solution of ethyl alcohol is used as an eluent. The pure fraction of D-psicose is purified with activated carbon, concentrated to a syrup and lyophilized. The invention has extensive use at the stage of biochemical processes in medicine in bioengineering in the preparation of new nucleosides.

Description

The invention relates to a process for the preparation of D-psicosis.

D-psicosis is a very rare carbohydrate of ketose. The best known method of preparing D-psicosis is Lobry de Bruyn-Albert von Ekenstein's transformation. Using weakly basic calcium oxide, pyridine or triethylamine reagents to monosaccharides such as D-glucose, D-allose, D-fructose, D-psicose was prepared by utilizing the unwanted carbohydrates from the resulting isomerization mixture by yeast [C. A. Lobry De Bruyn, W. Alberda van Ekenstein: Rec. Trav. Chim. Pays-Bas. 14, 203 (1895), M. Steiger, T. Reichstein, Helv. Chim. Acta 19, 184 (1936); S. Passeron; E. Recondo: J. Chem. Soc. 813, (1965), F. W. Zerban, L. Sattler, Ind. Eng. Chem. 34, 1180 (1942), L.W. Doner: Carbohydr. Res. 70, 209 (1979)], [V. Bílik, K. Tihlárik: Chem. rumors 28, 106 (1974)], prepared D-psicosis from D-fructose by epimerization using molybdate ions. D-psicosis was also prepared synthetically by multi-step synthesis. From D-fructose, a derivative of 1,2-4,5-di-O-isopropylidene-D-fructopyranoside was prepared and oxidized to the 3-ketoderivative which was stereospecifically reduced to 1,2-4,5- with the aid of sodium borohydride. di-O-isopropylidene-β-D-pricopyranoside, from which D-psicose was released by hydrolysis. (EJ McDonald: Carbohydr. Res. 5, 106 (1967); RS Tipson, RF Brady Jr., BF West: Carbohydr. Res. 16, 333 (1971)). Methods for preparing D-psicose from D-glucose and D- fructoses are not technically demanding but with pyridine at the boiling point as well as its removal on a preparative scale is difficult to achieve from a safety and environmental point of view The D-allose preparation process is only of theoretical importance for the high cost of the base material which is rare and difficult to obtain Synthetic preparation of D-psicose gives a better yield, but in this process the synthesis consists of a multistep, making the preparation expensive for chemicals and equipment.

The above-mentioned disadvantages are substantially eliminated by the process for the preparation of D-psicose according to the invention, which consists in the fact that the aqueous solution of D-fructose is catalytically isomerized by means of a strongly basic ion exchanger in hydroxide form at temperatures of 80 to 100 ° C for 8 to 12 hours. wherein a suitable equilibrium mixture of D-glucose, D-mannose, D-fructose and D-psicose sugars is formed. This mixture is selectively separated by means of a strong acid cation exchanger in calcium form. A 40-60% aqueous ethanol solution was used as eluent. the pure D-psicose fraction is concentrated on a rotary evaporator to a syrup and lyophilized.

The advantage of the proposed process for the preparation of D-psicosis over the prior art processes is that the present process is simpler and more efficient. Allows you to work in simpler devices that are commonly available. It allows to work without substances that are harmful to health like pyridine, which is a particularly dangerous poison, pollutes the environment, and its removal on an industrial scale requires special equipment, making preparation expensive. The unreacted starting material can be used in the entire reaction in the next reaction as well as the ion exchanger after simple activation. The product is of high purity. Example 1

A mixture of D-fructose (10 g), a strong basic ion exchanger Wolfatit SBW in hydroxide form (10 g) and water (100 mL) was stirred at 80 ° C for 12 h. The solution was separated from the ion exchanger by filtration, treated with activated carbon (1 g) and concentrated to a syrup (9.1 g). D isomerization mixture of D-glucose, D-mannose, D-fructose and D-psicose sugars (1 g) is dissolved in 40% aqueous ethyl alcohol solution (2 ml) and applied to a column packed with a strongly acidic Dowex 50 wx 8 o cation exchanger. 0.07 to 0.13 mm in a calcium form having a length of 100 cm and a diameter of 2.5 cm. A 40% aqueous ethanol solution was used as eluent. Using a fraction collector at a flow rate of 10 ml / h. the individual fractions were monitored by ascending paper chromatography (Whatman No 1 chromatography paper) in ethyl acetate, pyridine, water 8: 2: 1 by volume and detected by alkaline silver nitrate, or spectrophotometrically using 3,5-dinitrosalicylic acid. Fractions 1 to 19 were negative for sugars, fractions 20 to 24 contained D-glucose (0.37 g), fractions 25 to 28 were negative for sugars, fractions 29 to 32 contained D-mannose (0.14 g), fraction 33 Fractions 73-84 contained D-fructose (0.26 g), Fraction 85-160 was negative for sugars, Fractions 161-180 contained D-psicose (0.12 grams). The fraction containing D-psicose was concentrated on a syrup by rotary evaporation, purified by addition of activated carbon (0.2 g), filtered and lyophilized. D-psicose was obtained in 12% yield (α) η ^2θ + 3.9 ° (C = 2 HzO).

Example 2

A mixture of D-fructose (100 g), a strong basic ion exchanger Wofatit SBW in hydroxide form (100 g) and water (1000 mL) was stirred at 100 ° C for 8 h. The solution was separated from the ion exchanger by filtration, purified by addition of activated carbon (10 g) and concentrated to a syrup (93 g). D-glucose, D-mannose, D-fructose and D-psicose isomerization mixture (93 g) is dissolved in 60% aqueous ethyl alcohol and applied to a column packed with a strongly acid cation exchanger.

S (Dowex 50 wx 8, 0.07 to 0.13 mm in calcium form) with a length of 100 cm and a diameter of 10 cm. A 60% aqueous ethanol solution was used as eluent. Further work-up procedure according to Example 1. The obtained D-psicose (12.7 g) was in a yield of 13.6%, (a) _D ²⁰ + 3.6 ° (C = 2 HzO).

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The invention has extensive application in the study of biochemical processes, in medicine, in genetic engineering in the preparation of novel nucleosides. D-psicosis is a rare and hardly available carbohydrate.

Claims (2)

231545 S (Dowex 50 wx 8 with a grain size of 0.07 to 0.13 mm in calcium form) with a length of 100 cm and a diameter of 10 cm. A 60% aqueous solution of ethyl alcohol is used as the eluent. A further work-up procedure as described in Example 1. The D-psicose (12.7 g) obtained was in a yield of 13.6%, (iD 2 O + 3.6 ° (C = 2 HZO). The invention has extensive use in the study of chemistry processes, in medicine, in genius engineering for the preparation of new nuclosides. D-psicosis is one of the rare, hardly available carbohydrates. PREDMST A method of preparing D-psicosis, characterized in that D-fructose isomerized in an aqueous medium under the catalytic action of a strong basic ion exchanger in a hydroxide form at temperatures of 80 to 100 ° C, for 8 to 12 ha of the resulting isomerization DETERMINED the mixture is fed with a strongly acidic cation exchanger in calcium form with 40-60% ethyl alcohol as the eluent to isolate D-psicose, which is purified with activated carbon and lyophilized.