JPH08100002A - Method for producing cyclodextrin polymer - Google Patents

Abstract

(57) [Summary] [Object] To provide a cyclodextrin polymer having an unprecedented inclusion ability, which can introduce one cyclodextrin into one cellulose unit at a high introduction rate. A method for producing a cyclodextrin polymer, which comprises reacting a cellulose derivative with a cyclodextrin derivative in which one of the primary hydroxyl groups is left and the remaining hydroxyl group is protected by a protecting group.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a cyclodextrin polymer.

[0002]

Cyclodextrin is a cyclic oligosaccharide in which 6 or more units of glucose are α-1,4 linked, and those having 6,7,8 glucose units are particularly well known, and there are many known documents concerning their applications. In all of these application examples, the cyclodextrin ring has a hydrophobic interior, and the size of this ring is determined by the glucose unit amount. It is used for masking odors, catalysts, or foods for off-taste and odor, retaining volatile substances, and solubilizing poorly soluble substances.

It can be easily predicted that such selective inclusion ability will be an effective means for separation and extraction of hydrophobic substances, but since cyclodextrin is water-soluble, it can be used as a separation and extraction agent. , It is difficult to separate the clathrate compound from the reaction system and the clathrate compound from the cyclodextrin.

If cyclodextrin is immobilized on a polymer or the like while maintaining the inclusion ability, it is packed in a column, and the components are separated by adsorption / desorption operation or chromatographic operation like ion exchange resin or activated carbon. , Easy to collect and remove.

Therefore, various attempts have been made to immobilize cyclodextrin. However, the utilization rate of immobilized cyclodextrin is low, and the matrix polymer on which cyclodextrin is immobilized has a hydrophobic substance. Since they are adsorbed, the selectivity becomes insufficient, and the manufacturing cost is very high. Therefore, they are all unsuitable for industrially advantageous use.

For example, JP-B-55-27083, JP-B-55-41643 and JP-B-56-15806 describe a method for producing a polystyrene-based polymer having a cyclodextrin derivative. According to the method, one unit of the cyclodextrin derivative is always fixed to the styrene monomer, but in the polymer reaction, the reactivity is low and the fixed amount is not sufficient. In each of JP-A-55-75402 and JP-A-63-314201, cyclodextrin is polymerized at a position where the glycidyl group or the epoxy ring thereof is opened for immobilization. Even in this method, in order to bind a sufficient amount of cyclodextrin to the matrix, a reaction for a long time must be carried out, and the actually bound cyclodextrin is only a part of the charged amount, and it is necessary to One cyclodextrin cannot always be immobilized, and there is a problem in terms of economical efficiency in utilizing the excellent inclusion ability of cyclodextrin for various purposes.

On the other hand, cellulose itself or acetylated cellulose is generally excellent in film-forming properties and is widely used as a film base for various materials. Further, its structure is a linear polymer in which glucose is β-1,4-glucoside condensed, and is very similar to cyclodextrin.

Focusing on the characteristics of this cellulose, the one obtained by reacting cellulose with cyclodextrin and chemically bonding them is described in JP-A-57-57701. According to this method, it is not known which hydroxyl group of epichlorohydrin reacts with the cellulose unit, and in some cases, a plurality of epichlorohydrin may react with one cellulose unit. About the reaction of cyclodextrin derivative with this However, it is not known how many cyclodextrins are bound to one cellulose unit, and sometimes only one is bound,
There are cases where a large number are combined. Therefore, even if the same reaction is repeated, different things can be made each time.

[0009]

On the other hand, the inventors of the present invention have disclosed in JP-A-4-25505 an amino acid or
By reacting a cyclodextrin derivative having an ONa group with cellulose tosylate, or by reacting an acid chloride of carboxycellulose or carboxymethylcellulose with a cyclodextrin derivative having a cyclodextrin or an amino group or a hydroxy group, It was shown that one cyclodextrin could be introduced into the cellulose unit at a high introduction rate.

However, even in chromatography using the cyclodextrin polymer prepared by this method, it was difficult to separate optical isomers depending on the substance to be separated. It is considered that this is because the hydroxyl groups of the CD used in the above technique are not modified.

Therefore, the present invention provides a cyclodextrin polymer which is capable of not only introducing one cyclodextrin into one cellulose unit at a high introduction rate but also adjusting the separability according to various substances as compared with the prior art. It is intended to provide a manufacturing method.

[0012]

Means for Solving the Problems That is, the present invention is characterized in that a cellulose derivative is reacted with a cyclodextrin derivative in which one of the primary hydroxyl groups is left and the remaining hydroxyl group is protected by a protecting group. It is a method for producing a dextrin polymer. In this method, the cellulose derivative is preferably a cellulose acid chloride obtained by chlorinating carboxycellulose or carboxymethylcellulose.

[0013]

The present invention will be described in more detail below.

The cyclodextrin (hereinafter sometimes referred to as CD) derivative used in the present invention is α-C.
Any of derivatives such as D, β-CD, γ-CD can be used. And this CD derivative has 1 of primary hydroxyl groups.
The one in which the remaining hydroxyl groups are protected with a protective group is used. A method for producing these CD derivatives is disclosed in Japanese Patent Laid-Open No. Hei 5
It is described in detail in JP-A-1103. By selectively changing this protecting group, the selective adsorption property of the polymer finally obtained can be changed.

The cellulose derivative used in the present invention preferably includes cellulose tosylate, cellulose halide and the like; carboxycellulose; acid chloride such as carboxymethyl cellulose and the like. As the cellulose forming such a derivative, one having a molecular weight of about 50,000 or more is preferably used.

The reaction examples of the method for synthesizing the cyclodextrin polymer according to the present invention are shown below.

[0017]

Embedded image

[Example 1] Carboxycellulose (molecular weight: about 50,000) is chlorinated by using benzene as a solvent, pyridine as a base, and thionyl chloride. Under reflux 8
After reacting for a time, after completion of the reaction, the mixture is allowed to cool, filtered, the solvent is distilled off under reduced pressure, and the residue is reprecipitated from a large amount of dehydrated acetone. The obtained acid chloride of cellulose was dried under reduced pressure. The chlorination ratio was examined by measuring a nuclear magnetic resonance (NMR) spectrum and found to be about 90%. Next, 6-monohydroxy-permethyl β-CD, which was separately synthesized, was dissolved in dehydrated dioxane, and trimethylamine was added in a nitrogen atmosphere to 0 to 5 ° C.
Cool to. To the system is slowly added dropwise the acid chloride of carboxycellulose dissolved in dioxane. In addition,
The CD derivative and the cellulose derivative were mixed in such an amount that one CD derivative was used for each cellulose unit of the cellulose derivative. After the dropping, the mixture is allowed to react at 0 to 5 ° C. for 1 hour, then returned to room temperature and reacted for 24 hours. After completion of the reaction, the solvent is distilled off under reduced pressure, and the residue is poured into a large amount of benzene for reprecipitation. The obtained precipitate was washed well with n-hexane,
The target product is obtained by drying under reduced pressure (yield about 100%).
(See chemical formula 1). When the NMR spectrum of the obtained polymer was measured and the structure was analyzed, and the carboxyl group was further measured by the titration method, about 75% of the acid halogen groups were bound to the CD derivative.

[0019]

Embedded image

[Example 2] An object product is obtained in the same manner as in Example 1 except that carboxymethyl cellulose is used instead of carboxy cellulose (see Chemical formula 2). The chlorination rate of chlorinated carboxymethyl cellulose was about 95%.
The introduction rate of the CD derivative was about 75%.

[0021]

As described above, according to the method of the present invention, one cyclodextrin can be introduced into one cellulose unit at a high introduction rate. Further, since all the hydroxyl groups of cyclodextrin bound to cellulose are protected by a protecting group, it can be expected that the inclusion ability will greatly change.

Claims (2)

[Claims] 1. A method for producing a cyclodextrin polymer, which comprises reacting a cellulose derivative with a cyclodextrin derivative in which one of the primary hydroxyl groups is left and the remaining hydroxyl group is protected by a protecting group. 2. The method for producing a cyclodextrin polymer according to claim 1, wherein the cellulose derivative is a cellulose acid chloride obtained by chlorinating carboxycellulose or carboxymethylcellulose.