JPH085922B2 - Sulfinylethyl pullulan and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a novel pullulan derivative which has not been described in the literature, particularly as a thickener, a binder, a protective colloid agent, etc., and a selective permeation of sulfur dioxide and the like. The present invention relates to a useful sulfinylethyl pullulan as a material for a flexible film and a method for producing the same.

(Prior Art) Pullulan is a high molecular weight linear polymer in which maltotriose, which is a trimer of glucose, is repeatedly linked to each other through α-1,6 bonds. It is possible to separate and collect as an extracellular mucilage by culturing the strain. Unlike starch, which is composed of the same glucose units, it is soluble in both cold and warm water, its aqueous solution viscosity is relatively low, and it has excellent film-forming properties, hygroscopicity, and caking properties. I have.

(Problems to be Solved by the Invention) Conventionally, as a pullulan derivative obtained by subjecting this pullulan and a vinyl compound to a Michael addition reaction in the presence of an alkali catalyst, cyanoethylpullulan obtained by reacting pullulan with arylonitrile Is only known.

The present inventors have reached the present invention as a result of various studies on useful and novel derivatives of pullulan.

(Means for Solving the Problems) The present inventors (Wherein R represents an alkyl group having 1 to 6 carbon atoms), or When a phenyl vinyl sulfoxide represented by the following formula is reacted in the presence of an alkali catalyst, the general formula [Wherein each X is a hydrogen atom, (Wherein R represents an alkyl group having 1 to 6 carbon atoms), or an alkylsulfinylethyl group represented by: In the phenylsulfinylethyl group represented by, the average substitution degree of the alkylsulfinylethyl group and the phenylsulfinylethyl group per glucose unit is at least 0.
And n is an integer representing the number of repeating glucose units], and it was found that sulfinylethyl pullulans such as alkylsulfinylethyl pullulan and phenylsulfinylethyl pullulan, which are novel compounds, can be obtained, and the present invention completed.

 Hereinafter, the present invention will be described in detail.

In the sulfinylethyl pullulan of the present invention, the alkylsulfinylethyl group represented by the above formula (III) represents an alkyl group having 1 to 6 carbon atoms as R, and examples thereof include methyl, ethyl, propyl, butyl, Included are pentyl and hexyl groups.

Each glucose unit (ie, each anhydroglucose ring)
The average degree of substitution with the sulfinylethyl groups of the formulas (III) and (VI) (average number of sulfinylethyl groups present per glucose unit) is required to be at least 0.05. This is because if the average degree of substitution is less than this, the properties based on the sulfinylethyl group, such as the selective permeability of sulfur dioxide, will be insufficient.

As described above, the sulfinylethyl pullulan of the present invention is obtained by reacting pullulan with an alkyl vinyl sulfoxide represented by the formula (I) or a phenyl vinyl sulfoxide represented by the formula (II) in the presence of an alkali catalyst. It is obtained by.

The alkyl vinyl sulfoxide used here can be synthesized, for example, through a reaction step represented by the following formula.

_{RSH + C 2 H 5 ONa →} RSNa + C 2 H 5 OH RSNa + ClCH 2 CH 2 OH → RSCH 2 CH 2 OH + NaCl [R in the above formulas is the same as formula (III)] That is, alkyl mercaptans are reacted with sodium ethoxide in ethanol at room temperature, and the resulting sodium thiolates are reacted with ethylene chlorohydrin to form hydroxyethyl alkyl sulfides. To synthesize. Then, the hydroxyethyl alkyl sulfide is dehydrated in a potassium hydroxide aqueous solution to give a vinyl alkyl sulfide, which is oxidized in an aqueous sodium metaperiodate solution to synthesize an alkyl vinyl sulfoxide.

Phenylvinyl sulfoxide can also be synthesized in the same manner as above using mercaptan as a starting material, but a commercially available product can also be used.

Further, as the alkali catalyst used in the above production method,
Sodium hydroxide, potassium hydroxide, sodium carbonate,
Examples include potassium carbonate and the like, but sodium hydroxide is usually economically advantageous.

The above production method is generally carried out by reacting both reaction components under stirring at 10 to 90 ° C. in an aqueous solution containing an alkali catalyst at a concentration of 0.5 to 10%. Generally, 1 mol of glucose unit in pullulan is reacted with vinyl sulfoxide in the range of 1 to 20 mol so as to obtain sulfinylethyl pullulan having a desired degree of substitution.
After the reaction, acetic acid was added to stop the reaction, and the reaction solution was poured into an acetone / methanol mixed solvent (2/3 volume ratio) to precipitate a product, which was dissolved in water or dimethyl sulfoxide, It can be purified by repeating the operation of reprecipitation with a mixed solvent of methanol or the like 2-3 times.

Since the sulfinylethyl pullulan of the present invention is a derivative having a structure in which a part of hydrogen atoms of the hydroxyl group of pullulan is substituted with an alkylsulfinylethyl group or a phenylsulfinylethyl group, the pullulan derivative is
When the hydrogen atom is dissolved in water having deuterium (D) (hereinafter referred to as “heavy water”) or dimethyl sulfoxide (hereinafter referred to as “heavy DMSO”) and subjected to proton nuclear magnetic resonance ( ¹ H-NMR) spectrum analysis, In addition to the absorption of pullulan used as a raw material (see Fig. 1, measured at 270MHz in heavy water), a new alkylsulfinylethyl group, especially SO
Unique absorption of hydrogen bonded to adjacent carbons is observed (second
~ L) and m) in Fig. 4).

Further, in the case of phenylsulfinylethyl pullulan, absorption of protons of the phenyl group is recognized around 7.5 ppm (see m in FIG. 5).

On the other hand, the signal of the proton of the vinyl group of vinyl sulfoxide which is the starting material is not observed (see FIGS. 2 to 5).

These facts indicate that the hydroxyl group of pullulan is added to the vinyl group of vinyl sulfoxide and the sulfinylethyl group is introduced to obtain the sulfinylethyl pullulan having the above-mentioned structure.

The spectroscopic characteristics of the sulfinylethyl pullulan of the present invention shown by ¹ H-NMR spectral analysis are as follows.

Alkylsulfinylethyl pullulan: ¹ H-NMR (heavy water) δ ppm, Phenylsulfinylethyl pullulan: ¹ H-NMR (heavy DMSO) δ ppm, (Examples) Hereinafter, specific embodiments of the present invention will be described by way of examples, but the present invention is not limited to these examples.

Examples 1 to 3. 0.1 g of pullulan (trade name: PI-20, manufactured by Hayashibara Co., Ltd.) was added to 20 ml of water and dissolved, and then methyl vinyl sulfoxide (referred to as MVSO in the table) is shown in Table 1. It was added at a molar ratio with pullulan (indicated as PL in the table) per glucose unit shown. Then, 1% by weight of the whole system of sodium hydroxide was added, and the mixture was reacted at 60 ° C. for 5 hours with stirring, and the obtained reaction product was neutralized with acetic acid. Next, this was poured into an acetone / methanol (volume ratio 2/3) mixed solvent to precipitate a reaction product. The operation of dissolving the precipitate in water and reprecipitating with acetone / methanol was repeated 3 times for purification.

The average degree of substitution of the obtained methylsulfinylethyl pullulan was determined from ¹ H-NMR measurement. These results are first
It is also shown in the table. The ¹ H-NMR spectrum of the methylsulfinylethyl pullulan obtained in Example 3 (in heavy water,
(Measured at DS1.68, 270 MHz) is shown in FIG.

Examples 4 to 8. The same operation as in the previous example was carried out except that ethyl vinyl sulfoxide (EVSO in the table) was used instead of methyl vinyl sulfoxide and the reaction conditions shown in Table 2 were used. The results are also shown in Table 2. ¹ H-NMR of ethylsulfinylethylpullulan obtained in Example 8
Third spectrum (measured at DS1.37, 270MHz in heavy water)
As shown in the figure.

Examples 9 to 11. The same operation as in Examples 1 to 3 was performed except that tert-butyl vinyl sulfoxide (in the table, referred to as BVSO) was used in the molar ratio shown in Table 3 instead of methyl vinyl sulfoxide. went. These results are also shown in Table 3. The ¹ H-NMR spectrum of tert-butylsulfinylethyl pullulan obtained in Example 11 (measured at DS1.15 and 270 MHz in heavy water) is shown in FIG.

Examples 12 to 14. The same operation as in Examples 1 to 3 was performed except that phenylvinyl sulfoxide (in the table, PVSO) was used instead of methyl vinyl sulfoxide in the molar ratio shown in Table 4. . The results are also shown in Table 4. Example 14
¹ H-of phenylsulfinylethyl pullulan obtained in
NMR spectrum (measured at DS1.69, 270 MHz in heavy DMSO)
Is shown in FIG.

(Effect of the invention) Since the sulfinylethyl cellulose of the present invention dissolves in water or dimethylsulfoxide, a thickener, a binder,
In addition to being useful as a protective colloid agent, a film obtained by casting the colloidal agent can be expected to be applied as a material for selectively permeating sulfur dioxide.

[Brief description of drawings]

In the figure, FIG. 1 is a ¹ H-NMR spectrum of pullulan which is a starting material of sulfinylethyl pullulan of the present invention. FIG. 2 and subsequent figures relate to the present invention, and FIG.
¹ H-NM of methylsulfinylethyl pullulan obtained in
R spectrum, FIG. 3 is a ¹ H-NMR spectrum of ethylsulfinylethyl pullulan obtained in Example 8, and FIG. 4 is a ¹ H-NMR spectrum of tert-butylsulfinylethyl pullulan obtained in Example 11. FIG. 5 shows ¹ H-NMR of phenylsulfinylethyl pullulan obtained in Example 14.
The spectra are shown respectively.

Claims (2)

[Claims] 1. A general formula [Wherein each X is a hydrogen atom, (Wherein R represents an alkyl group having 1 to 6 carbon atoms), or an alkylsulfinylethyl group represented by: In the phenylsulfinylethyl group represented by, the average substitution degree of the alkylsulfinylethyl group and the phenylsulfinylethyl group per glucose unit is at least 0.
05, and n is an integer representing the number of repeating glucose units]. 2. Pullulan, (Wherein R represents an alkyl group having 1 to 6 carbon atoms), or The method for producing sulfinylethyl pullulan according to claim 1, wherein the phenylvinyl sulfoxide represented by the formula (1) is reacted in the presence of an alkali catalyst.