CS251992B1 - A method of preparing 1,6-anhydro-2,3-di-O-acetyl- (β-D-glucopyranose) - Google Patents

Abstract

The process provides a method for the stereospecific preparation of 1,6-anhydro-2,3-di-O,-acetyl-(3-D-glucopyranose. The above purpose is achieved by catalytically treating 1,6-anhydro-2,3,4-tri-O-acetyl-(S- -D-glucopyranose with Aureobasidium pullulansccy 27-1-14 cells in a buffer solution with a pH of 5.0 to 5.8, wherein a suitable buffer solution is citrate phosphate or malate phosphate. The solution is of importance in the chemistry and biochemistry of carbohydrates.

Description

(54) Preparation of 1,6-anhydro-2,3-di-O-acetyl- ₍ 1'-D-glucopyranose)

2

The process solves a process for the stereospecific preparation of 1,6-anhydro-2,3-di-O, -acetyl- (3-D-glucopyranose). -tri-O-acetyl- ₍ SD-glucopyrapose) is catalytically treated with Aureobasidium pullulans cells 27-1-14 in a buffer at pH 5.0-5.8, with phosphate citrate or malate-phosphate citrate as a suitable buffer.

The solution is important in carbohydrate chemistry and biochemistry.

The present invention relates to the stereospecific preparation of 1,6-anhydro-2,3-di-O-acetyl-4-glucopyranose.

Partially acetylated derivatives of 1,6-anhydro- (3-D-glucopyranose) are preferred starting materials in the preparation of many compounds such as amino derivatives, methyl derivatives, oligosaccharides, etc. by partial acetylation of 1 H -anhydro-4-D-glucopyranose [D. Shapiro et al. J. Org. Chem. 35, 1464 (1970)], by chemical hydrolysis of 2,3,4-tri-O-acetylderivative 1,6- anhydro-β-D-glucopyranose [S. Kučár et al. Collection Czech. Chem. Commun. 49, 1780 (1984)] or by enzymatic hydrolysis (J. Zemek et al. Ρ V 7046/84).

A disadvantage of the first two processes is the low stereospecificity of the reaction, which in most cases results in a mixture of mono-di-O derivatives. In enzymatic hydrolysis, the stereospecificity of the reaction is substantially increased (yield of 2,3-di-O-acetylderivative is 70 to 75 percent), however, the disadvantage is the need to prepare purified enzyme systems.

· Said shortcomings are significantly eliminated by the new procedure in accordance with embodiment of the invention, whose principle consists in that, on the _{1,6-anhydro-2,3,4-Itri-O-acetyl-3-one} D-glucopyranose is catalytically treated yeast cells Aureohasidium pullulans CCY 27-1-14, in an aqueous buffer solution of pH 5.0 to 5.8 at 20 to 40 ° C.

The advantage of the present method is its simplicity, stereospecificity, high yields of 1,6-anhydro-2,3-di-O-acetyl-β-D-glucopyranose in a single reaction step (~ 90 ° / o) and lower costs.

EXAMPLE 1 1,6-Anhydro-2,3,4-tri-O-acetyl / SD-glucopyranose (1 g) is dissolved in 10 ml of methanol, and 50 ml of citrate-phosphate buffer (0.05 moles) is added. ^-1 , pH 5.0) and cells isolated from Aureohasidium pullulans CCY 27-1-14 strain (0.5 grams) were added to this solution. The enzymatic hydrolysis is carried out at 40 ° C for 48 hours. The reaction solution is desalinated (Amberllt

The IR-120 (t + Aq) (Kle, amferlite IR-402 in the bicarbonate cycle) is concentrated to give a syrup containing 1,6-anhydro-2,3-di-O-acetyl-4-D-glucopyranose and 1,6-anhydro-2,3,4-tri-O-acetyl-β-D-glucopyranose 9: 1. Pure 1,6-anhydro-2,3-di-O-acetyl-β-D-glucopyranose (0.76 g, 90%) was prepared. chromatography on a column of silica in the ethyl acetate-benzene chromatography system (2: 1, v / v).

Example 1 and d 2

The procedure is as in Example 1 except that was used for malate-phosphate buffer (0.01 mol. ¹ I, pH 5.8). The enzyme hydrolysis is carried out for 24 hours at 20 ° C. After desalting the reaction mixture with an ion exchanger (amberlite IR-120 H ⁽⁺⁾ -cycles, amberlit IR-402 in a bicarbonate cycle) and concentration, a syrup is obtained which contains a mixture of 1,6-anhydro-2,3-di-0 -acetyl-β-D-glucopyranose (85%) and mono-O-acetyl derivatives

1,6-anhydro-β-D-glucopyranose (15%).

Chromatographic separation of the mixture on a silica column packed in ethyl acetate: benzene (2: 1, v / v) gave 0.72 g (85%) of pure 1,6-anhydro-2,3-di- O-acetyl- N -glucopyranose.

Example 3

The procedure was as in Example 1 except that Aureobasidium pullulans CCY 27-1-14 cells (1 g) immobilized by encapsulation in polyethyleneimine (0.1 gj with the addition of 2-chloromethyloxirane (0.02 g) at a temperature of 0.02 g) were used in the reaction. When immobilized A. pullulans cells were applied, the yield of 1,6-anhydro-2,3-di-O-acetyl- (2-D-glucopyranose) was 0.75 g (88.2%). allow for more than 20-fold use in the reaction mixture.

The invention can be widely used in the synthesis of glucose derivatives modified on the hydroxyl group at the C-4 position, or in the synthesis of oligosaccharides composed of D-glucose bound by α- or β-1,4 bonds and in the manufacture of medicaments.

Claims (1)

SUBJECT A process for the stereospecific preparation of 1,6-anhydro-2,3-di-O-acetyl- [2-D-glucopyranose], characterized in that 1,6-anhydro-2,3,4-tri-O-acetyl -D-Glucopyranose Catalyst of the Invention Relates with Aureohasidium pullulans CCY 27-1-14 cells at 0.01 to 0.05 moles. 1 ^_1 buffer pH 5.0 to 5.8 and a temperature of 20-40 ° C.