JPS5928561B2 - Novel amino sugar copolymer and its production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the formula: (wherein, n represents an integer from 130 to 150.

) and a method for producing the same.

Polymers of α-1,6-linked glucose can be used by microorganisms such as Leuconostoc messenteroides (L.
There is a dextran produced by eucOnOstOcmesenterOides).

Dextran itself is useful as a plasma expander, but its sulfate ester (dextran sulfate) has a lipid serum clarifying effect and lowers blood cholesterol and triglycerides. It also has anti-hyaluronidase and fibrinolytic effects, and is known as an effective drug for treating hyperlipidemia and arteriosclerosis. On the other hand, heparin, a mucopolysaccharide present in animal tissues, has a strong anti-blood coagulation effect.
It has a wide range of physiological effects such as lipid serum clarifying action, and is characterized by having sulfated amino sugar units, such as the following units, in its molecule.

(However, in the formula, X represents H or SO3-.

) Therefore, if it is possible to synthesize polysaccharides and sulfated products thereof that have α-1,6-linked sugar chains such as dextran and also contain amino groups such as heparin in their molecules, various physiological functions can be expected. However, polysaccharides having free amino groups are not naturally produced, and to date there have been no reports on the artificial synthesis of polysaccharides by polymerization of amino sugar monosaccharides. Therefore, in view of the above-mentioned purpose, the present inventors conducted intensive research and found that an amino sugar copolymer having α-1,6-linked sugar chains and containing an amino group such as heparin in its molecule was developed. They succeeded in synthesizing the compound and completed the present invention.

The present invention will be explained in detail below.

One of the starting materials of the present invention has the formula: (However, in the formula, Bn represents a benzyl group.

) is 3-azido-1,6-anhydro-3-deoxy-2,4-di-0-benzyl-β-D-glucopyranose (7), which was synthesized for the first time by the present inventors. It is a compound. The synthesis steps are shown below.
(However, in the formula, Bz represents a benzoyl group, Bn represents a benzyl group, and Ms represents a methanesulfonyl group.

: Compound (2) can be easily obtained by treating 1,6-anthro-β-D-glucopyranose (1) derived from β-D-glucopyranose with benzoyl chloride [M. Thank you very much.
liectiOnCzechOsiOvlChem. C
Omm plate. Vol. 26, 2542 (1961).
] Compound (2) 217 was dissolved in 500 ml of dry pyridine and cooled on ice.

Methanesulfonyl chloride 197 was added dropwise while stirring, and the temperature was gradually returned to room temperature. After 3 hours, the reaction mixture is poured into a large amount of ice water and stirred to precipitate crude crystals of compound (3).

After washing with water, drying, and recrystallizing from methanol, white crystals 177 (yield: 68%) are obtained. Compound (3) 10y
Dissolve in 50ml of chloroform and cool on ice.

A sodium methoxide solution prepared by dissolving metallic sodium 47 in 60 ml of methanol is added dropwise to this while stirring.

After the mixture was left at room temperature overnight, it was neutralized with 5% hydrochloric acid and concentrated to dryness under reduced pressure. The residue was extracted five times with 20 ml of acetone, and the extract was concentrated under reduced pressure to obtain an oil. When purified by silica gel column chromatography (developing solvent: chloroform-methanol, 100:1 v/v), compound (4-a) was obtained.
A mixture of 3.17 and (4-b) (yield 97%) is obtained.
[Physical properties of the mixture of compounds (4-a) and (4-b)] IR (film) (:RfL-1: 3400 6.7y of the mixture of compounds (4-a) and (4-b), Dissolve in 300 ml of dry tetrahydrofuran, add 2.87 g of sodium hydride (purity 60%) under ice cooling, and stir for 30 minutes.

Next, benzyl bromide 167 is added and reacted at room temperature for 4 hours. Add ice-cooled saturated ammonium chloride aqueous solution,
After stirring for 0 min, extract 3 times with 200 ml of ether. The extract was dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and the resulting oil was purified using silica gel column chromatography (developing solvent: benzene monoethyl acetate 20:1/v) to obtain an oily compound (5-a). The mixture of and (5-b) is 1
07 (yield: 86%). [Compound (5-a) and (
Physical properties of mixture of compound (5-b)] Compound (5-a) and (
The mixture 107 of 5-b) is dissolved in a mixed solvent of 200 ml of ethanol and 50 ml of saturated ammonium chloride water, 17.57 ml of sodium azide is added, and the mixture is heated under reflux for 60 hours while stirring.

After cooling, 500 ml of distilled water is added, ethanol is removed under reduced pressure, and the remaining aqueous solution is extracted with chloroform. The extract was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain an oil. When purified by column chromatography on silica gel (developing solvent, benzene-ether 20:1 v/v), a mixture of compounds (6-a) and (6-b) was obtained at 9.67% (
Yield: 81%). [Compounds (6-a) and (6-b)
Physical properties of the mixture] U = [υυ 9.3y of the mixture of compounds (6-a) and (6-b) is dissolved in 180 ml of dry tetrahydrofuran and cooled on ice.

Add 1.97 g of sodium hydride (purity 60%) and stir for 30 minutes, then add 11.5 g of benzyl bromide. After stirring at room temperature for 3 hours, ice-cooled saturated ammonium chloride aqueous solution 500 g
Add m1 and stir for an additional 30 minutes. This mixed solution is extracted with ether, and the extract is dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain an oil. Silica gel chromatography (developing solvent, hexane-ethyl acetate 5:1v/
When purified by step v), oily compound (7) 8y (yield 68%
). It crystallizes if left standing and can be recrystallized from cyclohexane.

(However, in the formula, Bn is the same as above.

) and can be easily obtained by treating 1,6-anthro-β-D-glucopyranose (1) with benzyl bromide or the like.

The thus obtained compounds (7) and (8) are copolymerized and reduced by the following method to obtain the amino sugar copolymer of the present invention. The copolymerization reaction is carried out by dissolving the compounds (7) and (8) in a sufficiently dried solvent and reacting with a Lewis acid as a catalyst.

Suitable solvents include methylene chloride and chloroform. Examples of the Lewis acid include phosphorus pentafluoride, antimony pentachloride, and boron trifluoride etherate, but phosphorus pentafluoride is most suitable from the viewpoint of yield and stereoregularity of the resulting copolymer. The amount of Lewis acid used is
), 2 to 7 mol%, particularly 2 to 3 mol%, based on the total number of moles of (8). In addition, compounds (7) and (8
) is preferably used in approximately equimolar amounts.
The reaction temperature is suitably about -30 to -60°C, and the polymerization time is suitably about 40 to 60 hours.

This polymerization reaction is carried out in vacuum or under an inert gas (e.g.
It is preferable to carry out in an atmosphere (N2 gas). Thus, an azide sugar copolymer (9) having azide groups in the molecule is obtained, which is then subjected to Birch reduction.

The reduction of copolymer (9) is carried out with an alkali metal in liquid ammonia.

Alkali metals include potassium, sodium, and lithium. It is necessary to add 6 or more atoms of alkali metal to 1 unit in the copolymer, and usually
the .・Appropriately, the amount should be about 3 times as much. The copolymer (9) is added by dissolving it in a suitable solvent such as 1,2-dioxyethane, diglyme, etc. The reaction temperature is suitably about -70 to -80°C,
A suitable reaction time is about 30 minutes to 3 hours. Thus, the amino sugar copolymer (10) of the present invention can be obtained.

(However, in the formula, Bn.n is the same as above.

) The present invention will be explained below with reference to Examples. Example 1 1,6-Anthro-3-azido-2,4-di0-benzyl-3-deoxy-β-D-glucopyranose (7)
(0.2507, 0.68 mm01) and 1,6-anthitro 2,3,4-tri-0benzyl-β-D-glucopyranose (8) (0.2947, 0.68 mm01
) was dried in a polymerization ampoule under a high vacuum of 10 −5 mmHg overnight and dissolved in methylene chloride (1.0 mO) previously dried over calcium hydride.

After the polymerization tube is cooled with liquid nitrogen and the monomer solution is sufficiently frozen, phosphorus pentafluoride is introduced. The polymerization tube is disconnected from the vacuum line and shaken vigorously for 1 to 2 minutes in an ethanol solution at 60°C. After reacting at -60°C for 1 hour, the polymerization ampoule was opened and methanol was poured to stop the reaction.
At this time, the polymer precipitates, so chloroform is added to it until the polymer is sufficiently dissolved, neutralized with an aqueous sodium bicarbonate solution, washed with water, and dried over anhydrous sodium sulfate. After removing the desiccant, the sap liquid is concentrated and
Add petroleum benzene and re-sediment. The operations of dissolving, concentrating, and reprecipitating were performed two more times, then dissolved in benzene, and freeze-dried to obtain azido sugar copolymer (9) 0.44757 (82
．． 3%). Example 2 Polymer (9) (0.20y) was added to 1,2-dimethoxyethane (10ml) which had been previously dried with metallic sodium.
dissolve in

Claims (1)

[Claims] 1. An amino sugar copolymer represented by the following formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (wherein, n represents an integer from 130 to 150). 2 Structural formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, Bn represents a benzyl group.) Compounds and structural formulas represented by: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, the formula (In the formula, Bn is the same as above.) is copolymerized in the presence of a Lewis acid catalyst to form the formula: ▲ Numerical formula, chemical formula, table, etc.▼ (However, in the formula, Bn is the same as above. and n is 13
Indicates an integer from 0 to 150. ) is obtained, and the copolymer is treated with an alkali metal in liquid ammonia to obtain the formula: ▲ Numerical formula, chemical formula, table, etc. ▼ (However, in the formula, n is the same as above. .) A method for producing an amino sugar copolymer, characterized by obtaining an amino sugar copolymer represented by 3 Claim 2 in which the Lewis acid is phosphorus pentafluoride
Manufacturing method described in section.