CS239597B1 - Preparation method of melibiose and d-fructose - Google Patents

Abstract

The invention relates to a process for preparing the biose and D-fructose. The essence of the invention resides in that 40 to 70 wt. water solution of melibiose and D-fructose in 35 to 55% wt. ethanol selective fractionates on an ion exchange column functional sulfo groups in calcium form, from which 35 to 55% by weight is eluted. ethanol, concentrated and crystallized. The invention of can find wide use in biochemical studies bioengineering and medicine.

Description

The invention relates to a process for the preparation of melibiosis and D-fructose.

Melibiosis as well as D-fructose are rare carbohydrates. Melibiosis is a reducing disaccharide of 6-O-α-D-galactopyranosyl-D-glucopyranose. In nature it is isolated. Most often it is prepared by acidic or enzymatic hydrolysis of raffinose [C. Hudson, S. S. Harding, J. Am. Chem. Soc. 37, 2734 (1915); T. S. Harding: Sugar 25, 544 (1923); A. Wickstrom, J. E. Coutois, P. Le Dizet, A. Archambault: Bull. Soc. Chim. France 1410 (1958). It can also be prepared by partial hydrolysis of tetrasaccharide and pentasaccharide isolated from Lychnis dioica [F. J. Bates: Polarimeters, Saccharimeters and Sugars, Waschington 473 (1942)]. H. S. Isbell prepared melibiosis from raffinose fermentatively using baker's yeast [H. S. Isbell: Preparation and Properties of Sugars and their Derivatives 473 (1966)]. F. Rendoš and A. Ondrejkovič prepared melibiosis by fractional crystallization after partial hydrolysis of raffinose [Cs. AO 169453]. D-fructose was prepared by hydrolyzing insulin polysaccharide [J. Honeyman: Methods in Carbohydrates of Chemistry Vol. I, 116 (1962). The methods for the preparation of melibiosis and D-fructose are complicated and chemical and equipment intensive. A further disadvantage is that melibiosis and D-fructose contained various colloidal substances which had to be laboriously removed.

The above-mentioned disadvantages are substantially eliminated by the process for the preparation of melibiosis and D-fructose, which consists in the fact that 40 to 70 wt. % aqueous solution of melibiosis and D-fructose in 35 to 55 wt. ethanol is chromatographically selectively fractionated on a sulphonated ion exchange column in calcium form, from which 35 to 55 wt. ethanol, concentrated and crystallized.

The advantage of the proposed process for the preparation of melibiosis and D-fructose over the prior art processes is that the present process is simpler, more efficient and more economical. It allows to prepare both rare carbohydrates melibiosis and D-fructose in one stage. No by-products are produced during the preparation and the products produced are crystalline substances of high purity.

EXAMPLE

To a solution of 25 g of raffinose in 250 ml of water is added 25 g of sulfonated ion exchanger (Wofatit KPS 200 0.3 to 0.85 mm) and hydrolyzed at 60 ° C for 8 h with stirring. The hydrolyzate is separated from the ion exchanger by filtration and concentrated to 21 g of syrup. Dissolve 2 g of this syrup in 2 ml of 35 pens. wt. of an aqueous ethanol solution and applied to a column packed with a sulfonated functional monomer in calcium form (Dowex 50 W X 8 0.07 to 0.13 mm) with a column length of 100 cm and a column diameter

2.5 centimeters. A 35% by weight aqueous ethanol solution was used as eluent. Using a fraction collector at a flow rate of 10 ml. h ^_1, individual fractions of a stream of descending paper chromatography Afio ^ (Whatman No. 1) in the system ctylacetát: pyridine: water in a ratio of 8: 2 ': 1, and detects aniliniumhydrogénftalátom and 3,5-dinitrosalicylic acid spectrophotometrically at 575 nm. Fractions 1 to 11 were negative for sugars, fractions 12 to 25 contained 1.16 g melibiosis, fractions 26 to 32 were negative for sugars, fractions 33 to 0.56 g D-fructose. The fractions containing the pure sugars melibiosis and D-fructose are individually concentrated on a rotary evaporator, purified by addition of 0.5 g of activated carbon, filtered and crystallized in 5 ml of ethanol. Melibiosis had an optical rotation of (α) _D ²⁰ + 136 ° (c = 2 water) melting point 179-181 ° C was obtained in 95.7% yield. D-fructose has had an optical rotation of (a) _{D @} ²⁰ - 92 ° (c - 2 water), melting point 103-105 DEG C. was obtained in 92.5% yield.

Example 2

The procedure was as in Example 1, except that it was hydrolyzed at 80 ° C for 6 h and 55% by weight was used as eluent. ethanol. Melibiose had an optical rotation of (a) _D ²⁰ + 134 ⁰ [c = 5, water), melting point 179-180 DEG C. to give a yield of 93+ percent, D-fructose has had an optical rotation of (a) N ^20-91 ° ( 103 DEG-104 DEG C. was obtained in 94.2% yield.

Example 3

The procedure is as in Example 1 except that it is used as the eluent

42.5% w / w ethanol. Fractions 1 to 15 were negative for sugars, fractions 16 to 30 contained 1.17 g melibiosis, fractions 31 to 35 were negative for sugars, and fractions 36 to 52 contained 0.55 g D-fructose. Melibiosis had an optical rotation of (α) _D ²⁰ + 135 ° (c = 2 water), melting point 180-181 ° C, and was obtained at

96.5% yield. D-fructose had an optical rotation (a) of ^20-92 ° (c 2, water), melting point of 103 to 104 ° C, was obtained in 91.0% yield.

The invention can find wide application in the study of biochemical processes in bioengineering and medicine.

Claims (1)

FRED Μ Ε Τ A process for the preparation of melihiose and D-fructose by hydrolyzing raffinose in aqueous solution by catalysing an ion exchange functionalized sulfo group, characterized in that 40 to 70 wt. % aqueous solution of melihiose and D-fructose in 35 to 55 wt. ethanol graphically selectively fractionates on a sulphonated ion exchange column in calcium forms from which 35 to 55 wt. ethanol, concentrated and crystallized