JP2007169413A - Inclusion carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inclusion carrier composed of water-soluble polysaccharides imparting high hydrophilicity and modifying inclusion ability while utilizing advantages essential to the polysaccharides such as slight adverse effects on environments or human bodies. <P>SOLUTION: The inclusion carrier is characterized in that the carrier is composed of the water-soluble polysaccharides in which a carboxy group or various salts of the carboxy group are introduced by selectively oxidizing primary hydroxy groups of a monosaccharide constituting the polysaccharides. The primary hydroxy groups of the polysaccharide can selectively be oxidized in the presence of an N-oxyl compound with a co-oxidizing agent by dispersing or dissolving the polysaccharides in an aqueous system. The inclusion composite obtained by including an active component such as a food, a cosmetic, a medicine, ink or an agrochemical in an inclusion carrier is utilized in the fields of the food, the cosmetic, the medicine, the ink, the agrochemical, etc. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inclusion carrier that can be used in the fields of foods, cosmetics, pharmaceuticals, inks, agricultural chemicals and the like by including active ingredients such as foods, cosmetics, pharmaceuticals, inks and agricultural chemicals.

  Regarding the inclusion complex, various researches and developments have been made so far, and various application fields have been established industrially. Flavor and flavor masking in the food field, powdering of oils and liquids, volatile components and other substances, improved solubility, separation and purification in pharmacy and chemistry, synthesis of highly regular compounds, inks, pesticides, activity Applications are being studied in various fields such as stabilization and detoxification of high-drug drugs, sustained release, and the formation of nanomaterials utilizing the ability to control the structure at the molecular level.

  Examples of the host material for inclusion include low molecular weight compounds such as urea, cyclodextrin, crown ether, and the like. In the case of high molecular weight substances, inorganic layered minerals, starch (amylose), and cellulose are also used for inclusion. Yes. In particular, polysaccharides having a high molecular weight are also effective for inclusion of guest substances having a high molecular weight, such as proteins and nucleic acids.

  On the other hand, polysaccharides have been used for various purposes such as food, fuel, clothing, and textile printing since ancient times. In recent years, natural polysaccharides have become a new type of biodegradable polymer materials and biocompatible materials. As a result, much research has been done on its use.

  Among them, starch is composed of linear amylose in which D-glucose is linked by α-1,4-glycosidic bonds and amylopectin having a structure branched by α-1,6, and there are various types of amylose wound between spiral structures. Include the substance. In order to improve or change the inclusion ability, or to suppress an insolubilization phenomenon called aging, modification such as adding various functional groups is performed to impart hydrophilicity. Cellulose and chitin are hardly soluble in water and other common solvents, and in terms of functional materials, their use has been limited compared to synthetic polymers, but various derivatizations have been invented. In addition, methods have been developed that dissolve in organic solvents such as acetone and chloroform, and even in water. However, these derivatives have a non-uniform distribution of substituents, and the synthesized derivatives are composed of monosaccharides that do not exist in nature, so the introduced substituents may affect the environment and the living body. There were problems such as.

  Therefore, recently, a technique has been invented in which a polysaccharide is oxidized in the presence of an N-oxyl compound catalyst to obtain water-soluble polyuronic acid. This oxidation method is a system in which a polysaccharide is dispersed in water or dissolved in an aqueous system such as 2,2,6,6-tetramethyl-1-piperidinyloxy radical (TEMPO) and sodium hypochlorite. The polysaccharide is oxidized while sequentially producing oxoammonium salts in the system using an oxidizing agent. It is applied to various polysaccharides such as cellulose and chitin from water-soluble polysaccharides such as starch and pullulan. Thus, the oxidized polysaccharide has a polyuronic acid type structure in which only the primary hydroxyl group is oxidized with high selectivity and converted to a carboxyl group or a salt thereof. Since this synthetic polyuronic acid has a uniform structure composed of naturally occurring sugars and has high water solubility, various reports have been made on its effectiveness.

Oxidation of polysaccharides using this N-oxyl compound as a catalyst involves using a catalyst such as sodium bromide in addition to an N-oxyl compound such as TEMPO in an aqueous reaction solution, such as sodium hypochlorite. Oxidation proceeds with the co-oxidant. Oxidation proceeds and carboxyl groups (
As the sodium salt increases, hydrophilicity is imparted to water-soluble polysaccharides such as starch as well as poorly soluble polysaccharides such as cellulose and chitin, and those that have undergone oxidation are solubilized in water.

  The present invention has been made in consideration of the above technical background, and imparted high hydrophilicity and improved inclusion ability while taking advantage of the inherent advantage of polysaccharides with less adverse effects on the environment and the human body. It is an object to provide an inclusion carrier comprising a water-soluble polysaccharide. The inclusion complex in which an active ingredient such as food, cosmetics, pharmaceuticals, inks and agricultural chemicals is included in the inclusion carrier of the present invention can be used in the fields of foods, cosmetics, pharmaceuticals, inks, agricultural chemicals, etc. It is.

  In order to achieve the above object, that is, the invention described in claim 1 introduces a carboxyl group or various salts of a carboxyl group by selectively oxidizing a primary hydroxyl group of a monosaccharide constituting a polysaccharide. An inclusion carrier comprising a water-soluble polysaccharide.

  The inclusion carrier according to claim 2, wherein the polysaccharide is starch, dextrin, pullulan, amylose, amylopectin, and derivatives thereof.

  The invention according to claim 3 is characterized in that the polysaccharide is dispersed or dissolved in an aqueous system, and a primary hydroxyl group of a monosaccharide is selectively oxidized using a co-oxidant in the presence of an N-oxyl compound. The inclusion carrier according to claim 1 or 2.

  The invention according to claim 4 is characterized in that the molecular weight of the water-soluble polysaccharide into which carboxyl groups or various salts of carboxyl groups are introduced by oxidation is in the range of 10,000 to 200,000. 4. The inclusion carrier according to any one of 3 above.

  The invention according to claim 5 is the inclusion carrier according to any one of claims 1 to 4, wherein the water-soluble polysaccharide is water-soluble polyuronic acid.

  According to the present invention, it is possible to obtain an inclusion complex formed by inclusion of various active ingredients by using a polysaccharide modified by introducing a carboxyl group by oxidation and imparting hydrophilicity as an inclusion carrier. became. In addition, since the inclusion carrier derived from a natural polysaccharide having a uronic acid residue with a controlled structure is used, antibacterial substances, insecticides, agricultural chemicals, food additives, fragrances, odorous substances, fats and oils, inks, Inclusion complexes containing active ingredients such as dyes, pigments, proteins, and nucleic acids are used for general industrial purposes, as well as chemical, pharmaceutical, agricultural, medical materials, food, hygiene products, cosmetics, etc. Can be used in the field.

  Hereinafter, an embodiment of the present invention will be described in detail. The polysaccharide imparted with hydrophilicity used in the inclusion carrier of the present invention can be obtained by oxidation of the polysaccharide. As the polysaccharide before being oxidized, water-soluble polysaccharides such as starch, pullulan, dextrin, amylose and hyaluronic acid, and cellulose and chitin can be used. Starch, cellulose, and chitin are preferred in view of the advantages of raw material procurement, cost, expected function, and water solubility with little change in structure. Furthermore, starch, amylose, amylopectin, and dextrin are preferably used as the oxidation raw material because the helical structure of the amylose portion of starch has a high ability to include substances.

  When a highly crystalline polysaccharide such as cellulose or chitin is used as a raw material, it is preferable to perform a treatment for reducing crystallinity such as a regeneration treatment as a pretreatment. As the regeneration treatment of cellulose, a known regeneration treatment method such as a cupra ammonium method or a viscose method can be used. In addition, the chitin regeneration treatment is not limited as long as the crystallinity of the chitin after regeneration is reduced. However, in consideration of subsequent use, etc., molecular regeneration occurs due to the regeneration treatment. That is not preferable. Thus, for example, alkali regeneration treatment can be mentioned. After dipping chitin in a high-concentration alkali, it becomes a viscous liquid by diluting under low temperature while adding ice. When neutralized by adding hydrochloric acid thereto, flaky chitin precipitates. The obtained chitin is almost amorphous, and it is washed thoroughly with water and not dried or freeze-dried, and then subjected to an oxidation reaction to suppress molecular weight reduction as much as possible, and almost all pyranose rings 6 Only primary hydroxyl groups can be oxidized to carboxyl groups.

  Alternatively, chitosan which is a deacetylated product of chitin may be used as a raw material, and a material that is N-acetylated under a uniform reaction may be subjected to an oxidation reaction. For example, after dissolving chitosan in acetic acid and diluting with methanol, it is easily N-acetylated by adding 1.5 to 3 times the molar amount of acetic anhydride relative to the amount of amino groups in the chitosan, and again chitin The chemical structure can be restored. By passing through this operation, the well-washed water is not dried or freeze-dried and subjected to an oxidation reaction, so that only the primary hydroxyl group at the 6-position is oxidized with high selectivity as in the case of alkali-regenerated chitin.

  Furthermore, in this case, it is also possible to control the degree of N-acetylation of the oxidation raw material by the amount of acetic anhydride added.

  As an oxidation method for obtaining polyuronic acid by oxidation of such a polysaccharide, an oxidation method should be employed which has a high selectivity to oxidation of primary hydroxyl groups and can obtain a uniform structure as much as possible, in the presence of an N-oxyl compound. A method using a co-oxidant is preferable.

  This selective oxidation method can control the degree of oxidation, and can oxidize almost all the 6-positions of the pyranose ring to a carboxyl group without oxidizing the 2-position or 3-position of the pyranose ring. Moreover, it is possible to perform an oxidation reaction in an aqueous system.

  As the N-oxyl compound, 2,2,6,6-tetramethyl-1-piperidine-N-oxyl (hereinafter, TEMPO) is preferably used. Examples of the oxidizing agent include halogens, hypohalous acids, halous acids and perhalogen acids, or salts thereof, halogen oxides, nitrogen oxides, peroxides and the like that can promote the target oxidation reaction. Any oxidizing agent can be used as long as it is an agent. Furthermore, it is more preferable to carry out the oxidation reaction in the presence of bromide or iodide because the oxidation reaction can proceed smoothly even under mild conditions and the introduction efficiency of carboxyl groups can be greatly improved. It is particularly preferable that TEMPO is used for the N-oxyl compound and the oxidation reaction is performed using sodium hypochlorite as an oxidizing agent in the presence of sodium bromide.

  Here, the amount of the N-oxyl compound is sufficient as a catalyst. For example, 10 ppm to 5% (ppc) is sufficient with respect to the number of moles of the constituent monosaccharide of the polysaccharide, but 0.05 to 3% is sufficient. More preferred. The amount of bromide or iodide used can be selected within a range that can promote the oxidation reaction. For example, it is 0 to 100%, more preferably 1 to 50%, based on the number of moles of the constituent monosaccharide of the polysaccharide. is there.

  In addition, for the purpose of improving the selectivity of oxidation of the constituent monosaccharides to primary hydroxyl groups and suppressing side reactions, it is desirable that the reaction temperature is room temperature or lower, more preferably 5 ° C. or lower. Furthermore, it is preferable to keep the inside of the system alkaline during the reaction. At this time, the pH is preferably 9 to 12, more preferably 10 to 11.

  Furthermore, in this oxidation method, the degree of oxidation can be controlled by the amount of oxidant and the amount of alkali added when the pH is kept constant. For example, when an alkali is added in an equimolar amount with a sugar residue, almost all primary hydroxyl groups at the 6-position of the pyranose ring are oxidized to carboxyl groups, and water-soluble polyuronic acid is obtained.

  The degree of oxidation in the inclusion carrier of the present invention is not particularly limited, and can be freely selected depending on the application and the degree of hydrophilicity. However, from the viewpoints of high hydrophilicity for formation of the inclusion complex in water and the uniformity of the structure, polyuronic acid that has been oxidized close to 100% is preferably used.

  For example, polyuronic acid obtained from starch has α-1,4-glucopyranose and α-1,4-glucuronic acid as constituent monosaccharides, and polyuronic acid obtained from cellulose is β-1,4-glucopyranose and β -1,4-glucuronic acid as a constituent monosaccharide, and polyuronic acid obtained from chitin is β-1,4-glucosamine and β-1,4-N-acetylglucosamine and β-1,4-glucosamineuronic acid and β- It has 1,4-N-acetylglucosaminuronic acid as a constituent monosaccharide. Hereinafter, these polyuronic acids are referred to as aminouronic acid, cellouronic acid, and chitouronic acid in this order.

  Thus, for example, in an aqueous solution containing a catalytic amount of sodium bromide and TEMPO, sodium hypochlorite is used as a co-oxidant, pH is adjusted using sodium hydroxide, and an oxidation treatment is performed in an alkaline system. The resulting polyuronic acid is dissolved in water as a sodium salt of a carboxyl group.

  After completion of the reaction, the reaction aqueous solution is generally dropped into a poor solvent such as ethanol to precipitate the water-soluble oxidized polysaccharide. After isolation, in order to remove salt and other reagents generated during the reaction, washing with an organic solvent containing water is repeated, and finally, after dehydration with acetone, drying is performed, or the reaction aqueous solution is subjected to dialysis. A method of purifying by removing reagents and impurities, or an isolation method such as washing with water after insolubilization with a calcium salt or the like is employed.

  Furthermore, the carboxyl group of the oxidized polysaccharide may be a free carboxyl group instead of a salt form. As the desalting method, an oxidized polysaccharide having a desalted carboxyl group can be obtained by adding hydrochloric acid to the aqueous solution or dispersion of the oxidized polysaccharide to a sufficient extent for desalting and purifying again. it can. Alternatively, the oxidized polysaccharide having a desalted carboxyl group can be easily obtained by treating an aqueous solution or dispersion of the oxidized polysaccharide with a cation exchange resin.

  These desalted carboxyl groups are more reactive than hydroxyl groups and have high water solubility or hydrophilicity, so they are very effective as reaction materials for secondary modification, and are derivatized before and after oxidation. Polysaccharides can also be used as an inclusion carrier.

  In particular, the above-mentioned chitouronic acid and amylouronic acid are water-soluble even in the COOH type, and are highly water-soluble in a wide pH range of pH 1-14. Depending on the guest substance included in the inclusion, the carboxyl group in the oxidized polysaccharide can be a bi-affinity substance having high hydrophilicity and affinity for organic solvents, in addition to being less hindered when it is COOH type. , May take up more material.

As described above, by introducing a highly polar functional group such as a carboxyl group into the polysaccharide that can be originally used as an inclusion compound by oxidation, the adsorptivity with the guest substance is improved. In addition, the hydrophilicity is increased, and the inclusion treatment in an aqueous system is facilitated, and more guest substances can be taken in.

  In particular, the product obtained by oxidizing starch by the above-described method is a polyuron composed of α-1,4-glucuronic acid having a substantially linear shape, in which α-1,6-branches derived from amylopectin originally present in starch are cleaved. Amilouronic acid, an acid, is obtained. In addition to the inclusion ability derived from the amylose skeleton, amyloulonic acid has a carboxyl group, which is a uniformly hydrophilic functional group, possibly outside the molecular chain. Therefore, amylouronic acid is entangled with hydrophobic guest substances such as fats and oils, and water can be solubilized with high water solubility of amylouronic acid.

  As described above, amylouronic acid is water-soluble in a very wide pH range. Alginic acid and ceurouronic acid are neutral to alkaline regions where the carboxyl group forms a salt with an alkali metal salt such as sodium or potassium, but the carboxyl group is precipitated in the free acidic region. End up. In contrast, amylouronic acid exhibits high water solubility even in an acidic region of pH 2 or lower, and exhibits high water solubility even if its carboxyl group is free. Therefore, it becomes possible to solubilize hydrophobic active substances in a wide pH range.

  In addition, in the various active ingredients serving as the inclusion guest substances in the present invention, antibacterial substances, insecticides, agricultural chemicals, food additives, fragrances, odorous substances, fats and oils, inks, dyes, pigments, proteins, nucleic acids, pharmaceuticals You can choose from a variety of medicines. In particular, since the polysaccharide of the present invention is a polymer, its selectivity, strength, and maintenance ability may be weak compared to cyclodextrins and the like. Various guest substances can be incorporated, including In addition, there is little that interferes with the function of the guest material.

  On the other hand, methods for preparing various inclusion complexes include techniques such as a saturated aqueous solution method, a kneading method, and an encapsulation method, but are not particularly limited. In order to maximize the merits of imparting hydrophilicity, it is preferable to mix the polysaccharide which is the inclusion carrier of the present invention and various active ingredients in the presence of water to obtain an inclusion complex. For example, oxidized polysaccharide is dissolved in water. When the polyuronic acids as described above are used, the solid content concentration can be kept at a high level, and when it is about 10%, it can be dissolved without any problem. The active substance is mixed in this aqueous solution. The active substance may be dissolved or dispersed in a solvent. In addition, it is often effective for inclusion of a guest substance to an oxidized polysaccharide to improve the dispersion of the active substance, an organic solvent, water, and the oxidized polysaccharide using a dispersant or the like.

  Thus, by bringing these substances into contact with each other in a system where water is present, the oxidized polysaccharide takes in the guest substance. Depending on the form of use thereafter, it can be dried and formed into powder, film, sheet, fiber, capsule, etc. The oxidized polysaccharide in which the inclusion complex of the present invention is a polymer It is one of the features by comprising.

  It is also possible to apply the liquid before drying as a coating agent to a substrate such as paper, film or fiber to form a coating film or knead. Moreover, you may mix and use additives, such as another base material, such as a binder and a bulking agent, or a plasticizer, in the inclusion complex of this invention.

  First, an example of a method for producing polyuronic acid as a raw material used in Examples and Comparative Examples described later will be described.

<Production Example 1>
(Preparation of amylouronic acid)
10 g of starch was dissolved by heating in 400 g of distilled water and cooled. In this solution, distilled water 1
A solution in which 0.18 g of TEMPO and 2.5 g of sodium bromide were dissolved in 00 g was added, and 104 g of an aqueous 11% sodium hypochlorite solution was added dropwise to initiate the oxidation reaction. The reaction temperature was always kept below 5 ° C. During the reaction, the pH in the system was lowered, but a 0.5 N NaOH aqueous solution was sequentially added to adjust the pH to 10.75. Then, when the amount of alkali added corresponding to 100% of the number of moles of the primary hydroxyl group at the 6-position was reached, ethanol was added to stop the reaction. When an aqueous solution in which 11 g of calcium chloride was previously dissolved in 100 g of water was added to the system, a white precipitate was formed. This precipitate was repeatedly washed with distilled water to obtain calcium amylouronate.

<Production Example 2>
The calcium salt of amylouronate prepared in Production Example 1 was suspended in 100 g of water and passed through a column filled with 70 mL of an ion exchange resin (organo Corporation: Amberlite IR120) regenerated into H-type for desalting treatment. It was. This aqueous solution of amylouronic acid was lyophilized to obtain 8.7 g of white powder of amylouronic acid.

<Production Example 3>
10 g of soluble starch was dissolved by heating in 200 mL of water. This aqueous solution was cooled to 5 ° C., 0.2 g of TEMPO and 2.5 g of sodium bromide previously dissolved in 50 g of water were added, and 104 g of an 11% aqueous sodium hypochlorite solution was added dropwise to initiate the reaction. The reaction temperature was maintained at 5 ° C. and the pH at 10.5. When the pH no longer drops, ethanol is added to deactivate excess oxidant. This aqueous solution is added to 2 L of ethanol while stirring to precipitate the oxidized polysaccharide, which is isolated by filtration. Wash several times with a mixed solution of water and acetone to remove impurities. After dehydration with acetone, it was dried under reduced pressure at 40 ° C. to obtain white amylouronate sodium salt.

<Production Example 4>
In the same manner as in Production Example 2, the amyloulonic acid sodium salt of Production Example 3 was treated to obtain amyloulonic acid of Production Example 4.

<Production Example 5>
The raw material of Production Example 3 was changed from soluble starch to amylose to obtain a sodium salt of oxidized polysaccharide in the same manner.

<Production Example 6>
As the regenerated cellulose, Benise manufactured by Asahi Kasei Kogyo Co., Ltd. was used. 10 g of regenerated cellulose was suspended in 400 g of distilled water. Until cooled. To this, 104 g of an aqueous 11% sodium hypochlorite solution was added dropwise to initiate the oxidation reaction. The reaction temperature was always kept below 5 ° C. During the reaction, the pH in the system was lowered, but a 0.5 N NaOH aqueous solution was sequentially added to adjust the pH to 10.75. Then, when the alkali addition amount corresponding to 100% of the number of moles of the primary hydroxyl group at the 6-position was reached, ethanol was added to stop the reaction. The reaction solution is poured into 1 L of ethanol to precipitate the product, thoroughly washed with a solution of water: acetone = 1: 7, dehydrated with acetone, and dried under reduced pressure at 40 ° C. The acid sodium salt was obtained.

<Production Example 7>
10 g of chitin manufactured by Wako Pure Chemical Industries, Ltd. was immersed in 150 g of 45% aqueous sodium hydroxide solution and stirred at room temperature or lower for 2 hours. The surroundings were cooled with ice water or the like, and 850 g of crushed ice was added with stirring. Chitin is almost dissolved by this alkali treatment. After neutralizing with hydrochloric acid, washing thoroughly with water and not drying, the raw material for oxidation was used.

  A solution prepared by dissolving 0.08 g of TEMPO and 1.0 g of sodium bromide in 50 g of distilled water was added to 200 g of the suspension having a regenerated chitin concentration of 2.5% and cooled to 5 ° C. or lower. An 11% sodium hypochlorite aqueous solution (35 g) was added dropwise thereto to initiate the oxidation reaction. The reaction temperature was always kept below 5 ° C. During the reaction, the pH in the system was lowered, but a 0.5 N NaOH aqueous solution was sequentially added to adjust the pH to 10.75. When the amount of alkali added corresponding to 80% of the total number of moles of the primary hydroxyl group at the 6th position is reached, ethanol is added to stop the reaction, and the reaction solution is put into 1 L of ethanol. Then, the product was precipitated, washed thoroughly with a solution of water: acetone = 1: 7, dehydrated with acetone, dried under reduced pressure at 40 ° C., and white powdery sodium chitouronic acid salt having an oxidation degree of 80% 5 0.2 g was obtained.

  The molecular weights of uronic acids prepared in Production Examples 3, 5, 6, and 7 were determined based on the following molecular weight measurement. The results are shown in Table 1.

<Molecular weight measurement>
The oxidized polysaccharides of Production Examples 3, 5, 6, and 7 were dissolved in 0.1% sodium chloride aqueous solution at a concentration of 0.2%, and the average molecular weight was calculated in terms of standard pullulan using two columns of TSKgel G6000PWXL and TSKgel G3000PWXL. Asked.

  Hereinafter, the present invention will be described with specific examples.

  0.2 g of limonene (manufactured by Kanto Chemical Co., Inc.) is dispersed in 20 g of an aqueous solution in which the obtained uronic acid prepared in Production Examples 1 to 7 is dissolved to a solid content concentration of 5%. Each aqueous solution was freeze-dried to prepare each limonene inclusion powder. 0.5 g of this powder solid was collected and dispersed in 5 mL of hexane to extract limonene. The amount of limonene included was determined by gas chromatography analysis of the hexane supernatant. On the other hand, as a comparative example, 0.2 g of limonene (manufactured by Kanto Chemical Co., Inc.) was added to 20 g of an aqueous solution in which soluble starch, amylose, α-cyclodextrin, and β-cyclodextrin before oxidation were dissolved to a solid content concentration of 5%. Disperse. Each aqueous solution was freeze-dried to prepare each limonene inclusion powder. 0.5 g of this powder solid was collected and dispersed in 5 mL of hexane to extract limonene. The amount of limonene included by gas chromatography analysis of the hexane supernatant was determined based on the following quantitative determination of limonene. The results are shown in Table 2.

<Quantitative measurement of limonene>
Gas chromatography / mass spectrometer (GC / MS) 6890/5973 manufactured by Agilent Technologies. 1 μL of limonene in hexane was injected into the GC / MS, the total ion chromatogram peak area of the detected limonene was determined, and the concentration of limonene in the sample was calculated from the calibration curve.

  Each limonene inclusion powder produced in Example 1 was placed in an open container and heated in an oven at 50 ° C. for 48 hours. Thereafter, 0.5 g of this powder solid was collected and dispersed in hexane to extract limonene. The amount of limonene included by gas chromatography analysis of the hexane supernatant was determined based on the same quantitative determination of limonene as in Example 1. The results are shown in Table 3. In Table 3, the ratio of the limonene concentration calculated in Example 1 to the limonene concentration calculated in Example 2 (limonene concentration calculated in Example 2 / limonene concentration calculated in Example 1) was obtained and shown. It is.

  From the results of Table 2, the inclusion content of limonene of uronic acid prepared in Production Examples 1, 3, 4, and 5 was not as great as that of Cyclodextrin in Comparative Examples 3 and 4, respectively. The value was the same as or higher than that of starch and amylose before oxidation, and it was found that the level was sufficient for use as an inclusion carrier. Moreover, from the results of Table 3, the inclusion content of limonene after the heating test in each of Production Examples 2, 3, 4 and 5 was larger than the unoxidized polysaccharides of Comparative Examples 1 and 2, and the limonene packaging before heating It was suggested that the ratio of the contact content was the same as that of cyclodextrin, and the included guest substance was firmly held.

  10 wt% aqueous solutions of the oxidized polysaccharides of Production Example 2, Production Example 3, and Production Example 6 were prepared. A 5% (w / v) acetone solution of hinokitiol was prepared. To 9 parts of the polysaccharide aqueous solution, 2 parts of an acetone solution of hinokitiol was added. The mixture was stirred for 1 hour at 50 ° C. in a sealed container. The powder was sufficiently dried by lyophilization to prepare a powder containing hinokitiol. As Comparative Example 5, a 10 wt% aqueous solution of β-cyclodextrin was prepared. Since cyclodextrin does not dissolve during the preparation of the solution, an aqueous solution was prepared by heating. Instead of the oxidized polysaccharide aqueous solution of Example 3, a β-cyclodextrin aqueous solution was used to repeat the method of Example to prepare a powdered hinokitiol-containing powder. The solubility and hinokitiol content were evaluated based on the following solubility evaluation method and hinokitiol content measurement method. The results are shown in Table 4.

<Solubility evaluation method>
Evaluation of the solubility when the inclusion compounds of Production Example 2, Production Example 3, Production Example 6 and Comparative Example 5 were dissolved in distilled water at 15 ° C. at a concentration of 1 wt% and when heated to 50 ° C. did.

<Method for measuring hinokitiol content>
The content of hinokitiol was determined using a calibration curve from the peak intensity at 241 nm of the UV absorption spectrum of each aqueous solution. The content was determined by the content percentage of hinokitiol in the inclusion compound.

  From the results shown in Table 4, regarding the content of hinokitiol, it was possible to include hinokitiol at the same level or higher than that of cyclodextrins that are widely used. Furthermore, regarding the solubility in water, it has been found that the oxidized polysaccharides of Production Example 2, Production Example 3, and Production Example 6 can be dissolved without any problem up to about 10 wt%. On the other hand, the β-cyclodextrin of Comparative Example 5 becomes more difficult to dissolve after inclusion.

  Further, the film forming property was evaluated based on the following film forming property test method. As a result, the oxidized polysaccharides of Production Example 2, Production Example 3, and Production Example 6 and β-cyclodextrin of Comparative Example 5 have relatively good film-forming properties, but hinokitiol does not form a film, It peeled off from the PET substrate. Moreover, although the comparative example 5 spreads uniformly like the comparative examples 1-4, the film | membrane became cloudy and the adhesiveness was also bad, and when it rubbed with the finger, it peeled off.

<Filmability test method>
Hinokitiol was dissolved in acetone at a concentration of 10%, and water was added thereto to prepare a 1% aqueous solution of hinokitiol. In addition, 1% aqueous solutions of the clathrate compounds of Examples 1 to 4 and Comparative Example 1 were prepared. This aqueous solution was applied onto a 25 μm-thick single-sided hydrophilic PET by a bar coater and dried at 120 ° C. for 30 minutes to attempt film formation.

Claims (5)

  An inclusion carrier comprising a water-soluble polysaccharide into which a carboxyl group or various salts of a carboxyl group are introduced by selectively oxidizing a primary hydroxyl group of a monosaccharide constituting the polysaccharide.   The inclusion carrier according to claim 1, wherein the polysaccharide is starch, dextrin, pullulan, amylose, amylopectin, and derivatives thereof.   3. The polysaccharide according to claim 1, wherein the polysaccharide is dispersed or dissolved in an aqueous system, and a primary hydroxyl group of a monosaccharide is selectively oxidized using a co-oxidant in the presence of an N-oxyl compound. Inclusion carrier.   The molecular weight of the water-soluble polysaccharide into which carboxyl groups or various salts of carboxyl groups are introduced by the oxidation is in the range of 10,000 to 200,000, according to any one of claims 1 to 3. Inclusion carrier.   The inclusion carrier according to any one of claims 1 to 4, wherein the water-soluble polysaccharide is water-soluble polyuronic acid.