WO1998008877A1 - Chitosan derivatives, process for producing the same and uses of the same - Google Patents

Abstract

Chitosan derivatives obtained by partly deacetylating chitin followed by reduction. These derivatives are comparable in solubility in water to the partly deacetylated but unreduced chitosan derivatives and have scarcely any taste or smell. They are highly stable and scarcely colored even when preserved at elevated temperature. These chitosan derivatives are comparable in activity to the conventionally known chitosan. When combined with hardly digestible dextrin, these derivatives exhibit an excellent effect of promoting defection, which makes them useful as drugs and foods.

Description

 Description of the Invention Chitosan Derivatives, Process for Producing the Same and Background of the Invention

 Field of invention

 The present invention relates to a novel chitosan derivative, a method for producing the same, and a medicament or food comprising the same. More specifically, the present invention relates to a chitosan derivative obtained by subjecting a partially deacetylated chitosan to a reduction treatment, a method for producing the same, and a medicament or food comprising this and an indigestible dextrin having an effect of improving constipation.

 Background technology

 In recent years, it has been reported that chitosan, which is obtained by deacetylating chitin, a constituent of shells such as Rikiji and Eze, interacts with cholesterol bile acid to inhibit absorption. Its effective use has attracted attention [M Sugan 0 et a1: Lipid, 23, 187 (1988), Y. Maejima et al: Biosci. Biotech. Biochem., 57, 1439 (1993)]. At present, chitosan has already been commercialized in the form of powders, tablets, and soft capsules, but chitosan used in these products hardly dissolves in water. Organic acids such as acids must be used. In addition, chitosan is known to form complex salts with minerals such as iron, magnesium, and calcium. <It is known that if taken in large amounts, it may inhibit the absorption of nutrient minerals. Furthermore, chitosan has an astringent non-astringent taste, and is not desirable to be incorporated into drinks, powders, and »j.

Various studies have been made to solve such problems. For example, low; ^? Chitosan has been developed to increase the solubility of chitosan. The effect of chitosan on cholesterol lowering is significantly reduced by And stability is problematic.

 Further, in order to reduce the edible taste of chitosan, taste masking using various additives has been studied (JP-A-2-283261). However, no sufficient improvement has yet been found.

 It is well known that when chitin is partially deacetylated, deacetylation can be obtained with soluble chitosan at about 50% [Sannan, S. et !: Macromol. Cliem., 1Π, 3589 (1976) ), The last biomass chitin, chitosan 1988)). However, no detailed studies have been made on the physical properties, stability, pharmacological action, and production of this chitosan derivative, and it has not been put to practical use. Further, according to experiments conducted by the present inventors, these partially acetylated products are liable to cause a browning reaction and lack stability.

 In addition, with the improvement in eating habits and the westernization of the United States, the TO of cereal foods containing complex polysaccharides such as starch has decreased, and the consumption of high-energy fat foods or refined processed foods has increased. Along with this, so-called adult diseases such as constipation, diabetes, hyperlipidemia and hypertension are increasing and becoming a major social problem.

In particular, long-term constipation not only causes discomfort, but also causes fecal accumulation in the intestinal wall of the large intestine, and it is said that this fecal impact causes various diseases such as cancer [Burkit ί, DP: Cancer, 28, 3 971), Burki tt, DP et al: Lancet, 30, 1408 (1972)]. Drugs for the purpose of improving constipation are mainly used as a laxative, such as salt laxatives such as magnesium oxide, swelling laxatives such as carmellose calcium, irritative laxatives such as visacodyl, and steep laxatives such as castor oil. I have. However, all of these drugs have the disadvantage that they are accompanied by discomfort such as ^ when taken, and also include the risk of fl¾7K due to severe and diarrhea. Therefore, products containing dietary fiber such as polydextrose and cellulose have been developed with the expectation of a more moderate effect, and the effect of promoting defecation is greatly affected by the fiber content in dietary fiber. In addition, a large amount of dietary fiber is iron, magne Shiumu, cause the absorption inhibition of minerals such as calcium [Makoto Nomura, et al .: Clinical Nutrition Journal, 13, I (1992)] suffer from problems such as, sufficient product development but now has not been _c

 Overview of the invention

 The present inventors have recently reported that, by further reducing the partially deacetylated chitosan, it is possible to obtain an extremely stable chitosan derivative which has high solubility and almost no astringent ego taste. Obtained knowledge. Further, they have found that this chitosan derivative has an activity equivalent to that of chitosan known hitherto, and also has an excellent defecation {¾! Effect when combined with indigestible dextrin. The present invention is based on such findings.

 Accordingly, an object of the present invention is to provide a chitosan derivative which is stable, has no taste and is effective, and a method for producing the same.

 Another object of the present invention is to provide a medicament or food containing the chitosan derivative, particularly a medicament or food having a constipation improving effect.

 The chitosan derivative according to the present invention can be obtained by partially deacetylating chitin and then subjecting the chitin to a reduction treatment.

 The medicament or food according to the present invention, especially a medicament or food having an effect of improving constipation, comprises the chitosan derivative according to the present invention and, in some cases, dietary fiber.

 Detailed description of the invention

 Chitosan derivative and method for producing the same

The chitosan derivative according to the present invention can be obtained by partially deacetylating chitin and then subjecting the chitin to a reduction treatment. More specifically, the chitosan derivative according to the present invention is obtained by treating purified chitin with an alkali at a low temperature to partially deacetylate, and then treating the terminal aldehyde with a τ-terminal component. Preferably, the reduction is with a borohydride reducing agent such as sodium borohydride. Also, this reduction is based on other reduction methods However, it is preferable that the degree of the reduction is the same as that obtained by sodium hydrogen boron.

 The chitosan derivative according to the present invention has the same water solubility as the partially deacetylated chitosan derivative before being subjected to the reduction treatment. Furthermore, it has the advantage that it has almost no taste and odor, is excellent in stability, and hardly discolors even when heated and stored.

 According to a preferred embodiment of the present invention, the degree of deacetylation is preferably from 20 to 80%, more preferably from 40 to 60%. Further, according to a preferred embodiment of the present invention, the average amount of the chitosan derivative is preferably 50,000 to 500,000 ^, more preferably 100,000 to 300. 0, 0 0 0.

 The structure of the chitosan derivative according to the present invention is considered to be a mixture of chitosan derivatives having a structure of ^ [type]. On the other hand, the chitosan derivative obtained by partial deacetylation and then subjected to a reduction treatment is used. If so, it may be understood that specifying the structure is not essential for practicing the present invention since it has the above advantages. However, as one possible embodiment of the present invention, the chitosan derivative according to the present invention is considered to be a compound represented by the following formula (I).

(I) (In the formula, n represents an integer of 20 to 140 °, R represents a hydrogen atom or a group COCH ₃ , wherein 20 to 80% of all Rs in the molecule represent a group COCH ₃ ). Further, in some cases, the compound represented by the above formula (I) may be further reduced by the above-mentioned reduction treatment, to give a structure of a chitosan derivative represented by the following formula (11).

(11)

(Wherein, n represents an integer of 20 to 1400, R represents a hydrogen atom or a group C〇CH ₃ , wherein 20 to 80% of all R in the group represents a group COCH ₃ ). May be a mixture of a compound represented by the above formula (I) and a chitosan derivative represented by the above formula (11) in some cases.

The method for producing a chitosan derivative according to the present invention comprises a step of partially deacetylating chitin and a step of reducing the partially deacetylated product. The reduction step S is specifically a step of reducing the terminal aldehyde of the partially deacetylinated product. The partial deacetylation step and the reduction step S may be respectively carried out according to known reactions. That is, partial deacetylation of chitin may be carried out by a known de-N-acetylation method, and can be preferably carried out by hydrolysis with heating with an acid or an acid. As described above, the reduction treatment is preferably performed using a borohydride reducing agent such as sodium borohydride. Also, the chitosan derivative according to the present invention In the method for producing a body, the partial deacetylation and the reduction treatment may be performed simultaneously. Applications of chitosan derivatives

 The chitosan derivative according to the present invention has the property that its water solubility is improved, its taste and odor are hardly strong, its stability is excellent, and it hardly discolors even when it is heated and stored. In terms of effective activity, it is equivalent to conventionally known chitosan. Therefore, the chitosan derivative according to the present invention can be basically used for conventionally known applications of chitosan and its derivatives. Specifically, the chitosan derivative according to the present invention may be used as it is or as a mixture with a carrier and optionally other biologically active compounds for the following uses. Food preservatives (using the antibacterial properties of chitosan), health foods (for example, utilizing the cholesterol-lowering effect of chitosan), drug delivery system (DDS) carriers, microcapsules, artificial, sutures, flocculants ( It can be used for applications such as aggregation of chitosan substances), chromatographic carriers (ion exchange, affinity chromatography), and functional membranes.

 Furthermore, the present inventors have found that the chitosan derivative according to the present invention has a constipation improving effect. This constipation-improving effect was made possible by using it in combination with dietary fiber, preferably indigestible dextrin.

 Therefore, according to the present invention, there is provided a pharmaceutical composition or food comprising the chitosan derivative according to the present invention, specifically, a pharmaceutical composition or food having a constipation improving effect.

The inconsistent dextrin used in the present invention is known per se, and for example, it can be synthesized according to Powder Science, 37, 107 (1990), or a commercially available one can be used. The composition of the chitosan derivative and the indigestible dextrin may be appropriately determined within a range where the constipation-improving effect can be obtained. For example, the weight ratio is preferably about 1: 1 to 1: 1000, more preferably 1: 1. : About 2 ~ 1: 500 Degrees.

 Both chitosan derivatives and indigestible dextrins are water-soluble and can be used as liquids or beverages. In addition, it can be made into ordinary pharmaceutical and food forms, for example, tablets, capsules, granules, powders and the like according to a conventional method. Further, it may be in a form in which a daily food or a food ingredient is added to the product.

 If necessary, usual excipients, binders, preservatives, sweeteners, vitamins, flavors, minerals and other auxiliary ingredients may be added. For example, one or a number selected from iron, heme iron, iron lactate, iron citrate, pyrophosphate "^, calcium, calcium dalconate, calcium lactate, calcium carbonate, magnesium, salt ^ magnesium, magnesium sulfate, etc. Different minerals can be incorporated.

 The amount is the total of the chitosan derivative and the indigestible dextrin per day, and is usually preferably 1 to 20 g / 60 kg body weight.

 The indigestible dextrins and chitosans mentioned above have already been used as food additives and their safety has been confirmed. Also, the chitosan derivative of the present invention obtained by the reduction treatment has no problem in safety.

 Example

 The present invention will be described in detail with reference to the following examples. The present invention is not limited to these examples.

 ^ [1: Production method of chitosan derivative (Part 1)

30 g of powdered chitin (80-mesh sieved product) was suspended in 700 g of a 40% sodium hydroxide solution and left at 25 ° C. under reduced pressure for 3 hours. While stirring the suspension, 2.3 kg of crushed ice was added thereto, and the suspension was left at 25 ° C for 77 hours. The solution was cooled to about 5 ° C, 2 kg of ice was further added, and the pH was adjusted to 8.5 with hydrochloric acid and dilute hydrochloric acid. Subsequently, this reaction solution was added dropwise to 20 liters of an acetone / water mixture (acetone: water = 7: 1) cooled to 0 ° C, and the formed precipitate was filtered, followed by acetone / water. After washing with the mixed solution, the mixture was dried under reduced pressure to obtain a white fiber-like partially deacetylated chitosan 21.

 20 g of the partially deacetylated chitosan obtained was dissolved in 2 liters of water, 2 g of sodium 7] c-borohydride was added, and the mixture was stirred at room temperature for 12 hours. The mixture was dropped into 10 liters of water and water. The resulting precipitate was filtered, washed with a mixture of acetate and water, and dried under reduced pressure to obtain a chitosan derivative (degree of deacetylation: 49.5).

%).

 : Method for producing chitosan derivatives (Part 2)

 30 g of powdered chitin (80-mesh sieved product) was suspended in 700 g of a 40% sodium hydroxide solution, and left under reduced pressure at 25 ° C for 3 hours. While stirring this suspension, 2.3 kg of crushed ice was added thereto, and 2 g of sodium borohydride was added thereto. Left at C for 77 hours. The solution was cooled to about 5 ° C, 2 kg of ice was further added, and the pH was adjusted to 8.5 with hydrochloric acid and dilute hydrochloric acid. Subsequently, this reaction solution was added dropwise to 20 liters of a mixture of acetone and 7 cooled at 0 ° C (acetone: water = 7: 1), and the formed precipitate was destroyed. After washing and drying under reduced pressure, a chitosan derivative was obtained (deacetylate: 50.5%).

 Example 3? "Stability of sun derivatives

 An aqueous solution (1% solution) of the chitosan derivative according to the present invention (degree of deacetylation: 50.2%) is stored at 50 ° C and 60 ° C for 14 days, and its stability is determined based on the change in color difference of the solution. Was examined. The color difference was measured using a color difference meter (manufactured by Nippon Denshoku Industries) with a 4 ° C storage sample as a control.

 For comparison, a non-reduced partially deacetylated chitosan solution (average ^^

20500, deacetylation degree 41%; Koyo Chemical Co., Ltd.) and low chitosan solution (average amount 4000, deacetylation degree: 69.7%; Kyowa Technos) (both 1% solutions) Add 12 g each of glucose and ferrous lactate to the solution. % And 0.012% were similarly evaluated.

 The results were as shown in Table 1 below.

 Furthermore, the chitosan derivative according to the present invention did not cause any precipitation due to the formation of a complex salt with iron ion, and was excellent in stability. Table 1 Stability of chitosan

 Color difference (m E value)

 Store at 50 ° C Store at 60 ° C

Chitosan derivative of the present invention alone 0.22 0.15 (unchanged glucose + iron 0.120.25 (no change) low ^^ chitosan alone 2.80 6.16 (yellowing)

 Glucose + iron 2..89 2.81 (browning) Non-reduced chitosan alone 1.56 2.05 (slightly yellowing) Glucose + iron 2.71 3.52 (slightly yellowing) Example 4: Sensory test for taste

 The chitosan derivative according to the present invention (degree of deacetylation: 50.2%), low chitosan (same as in Example 3) and commercially available chitosan (deacetyl) for healthy persons (5 males and 3 females) (Chemical degree: 88.3%) for powder and solution. I did. The egg taste of each solution was evaluated according to the following criteria, and the average score of each person's evaluation was obtained as an evaluation value.

Egg taste rating: 5 = intense

 4 = strong

2 = weak 1 = hardly feel

 0 = not at all

 The results were as shown in Table 2 below. Table 2 Chitosan Egg taste sensory test results

 Evaluation value

Commercial chitosan powder 3

Commercial chitosan solution (1% solution) 5

Low ^^ chitosan powder 0

Low molecular chitosan solution (1% solution) 1

Inventive chitosan derivative powder 0

Chitosan derivative solution of the present invention (1% solution) 1

* Commercial chitosan solution was prepared with 0.1% lactic acid solution. Example 5: Defecation promoting effect

120 g each of three water-soluble dietary fibers, indigestible dextrin, corn fiber, or polydextrose, and 10 g of partially deacetylated chitosan (degree of deacetylation: 50.2%) Was dissolved in purified water to prepare a test solution having a composition as shown in Table 3 below. The test solution was prepared using sodium chloride, potassium chloride, citric acid and sodium citrate so as to be almost isotonic solution (285-295 m0sm). Table ³ Composition of test solution

 Experiment 1 Experiment 2 Experiment 3 Indigestible dextrin 2%

 Corn fiber 12%

Polydextroth 12% Chitosan derivative of the present invention 1% 1% 1% Sodium chloride 0.117% 0.117% 0.11% Potassium chloride 0.037% 0.037% 0.037% Sodium citrate qs

 Quenchic acid 0.168% 0.168% 0.168% Commercially available purified feed (manufactured by CLEA Japan) was added with 5% chromic oxide and stirred uniformly to prepare a standard feed. 1 g of this standard feed was given to mice fasted for 12 hours, and 2 hours later, the test solution and physiological solution prepared above: ^ water (control solution) were orally administered at 30 ml / kg (0.9 ml / mouse). They were thrown and housed one by one in the breeding gauge, and fed lined food and lined water. Excretion feces were observed every 30 minutes after administration of the test solution, and green feces (feces colored with chromic oxide) were measured. The time until excretion was measured was defined as the defecation time.

The results were as shown in Table 4 below. As is clear from the table, the test solution containing dietary fiber and the chitosan derivative according to the present invention was confirmed to have a defecation promoting effect. . 2 Table 4 Effect of dietary fiber on defecation

 Defecation time (h)

 Control (physiology: ^ water) 5.80 ± 0.47

 Experimental example 1 3.69 ± 0.60 氺

 Experimental example 2 4.25 ± 0.39

 Experimental example 3 5.28 ± 0.49

 *: P <0.05 Example 5: Cholesterol lowering effect

 SD male rats (3.5 weeks old) are reared on powdered CE-2 diet (CLEA Japan) for 6 days, and divided into 8 animals per group based on blood total cholesterol, triglyceride, and body weight. did.

Each group was fed the experimental diet shown in Table 5 below for 20 days. All figures in the table are% by weight.

3 Table ⁵ Composition of experimental feed

 Example 4 Sample 5 Control feed A Control feed B Sucrose 60.17 49.17 60.17 60.17 Casein 20 20 20 20 Lard 1 ο10 10 10 Vitamin 1 1 1 1 Mineranore 4 5 4 5 weight Choline tartrate 0.2 0.2 0.2 0.2 0.2 Cholesterol 0.5 0.5 0.5 0.5 0.5 Cholic acid

 Sodium 0.13 0.13 0.13 0.13 Microcrystalline cellulose--4-Commercially available chitosan 4 According to the present invention

 Chitosan derivative 4 4

Indigestibility

 Dextrin 10

 * 1: Deacetylation degree: 88.3%

 * 2: Deacetylation degree: 50.2% After that, blood was collected from the tail vein to measure plasma cholesterol, triglyceride, and total lipid. In addition, the liver weight and sperm adhering fat amount of each rat were measured. The feed was freely lined.

The above results were as shown in Table 6 below. Table 6 Weight gain and blood fe¾chemistry Lame overnight Weight gain Serum total cholesterol Serum total lipid Serum phospholipids (g) (mg / d1) (mg / d1) (mg / d1) Group 4 158.7 ± 9.5 198. 72.5 176. is 12.2 Control diet B group 161.3 ± 4.7 190.9 ± 12.3 * 496.0 ± 36.5 * 133.9 ± 5.4 *

*: P <0.05 Table 7 Organ Weight

 Liver am testis attached fat

 (g / 100g body weight) (g / 100g body weight) Control feed group 4.57 ± 0.12 1 17 ± 0.13

 A feed group 4.28 ± 0.15 1 11 ± 0.09

 B feed group 4.04 ± 0.10 * 1 05 ± 0.09

 C feed group 4.01 ± 0.06 * 0 94 ± 0.10

 *: P <0.05 As is clear from the table, in the group fed the diet containing the chitosan derivative according to the present invention, all the blood chemistry parameters were significantly reduced as compared with the control diet group. It has been found that the chitosan derivative of the present invention also has a strong cholesterol lowering effect and a lipid absorption inhibiting effect equivalent to that of commercially available chitosan.

In addition, the liver weight of the commercial chitosan-containing diet group showed a tendency to decrease compared to the control diet group. On the other hand, with the chitosan derivative feeder according to the present invention, the liver weight was clearly reduced. In addition, the presence of fatty liver was observed in the control diet group. There was almost no II ^ in the diet containing sun derivatives. In addition, testis-adhered fat weight, which is an indicator of visceral fat, showed a decreasing tendency in the chitosan derivative-containing feed group according to the present invention. From these results, it is clear that the chitosan derivative according to the present invention is a material having a cholesterol lowering action and a fat absorption inhibiting action.

 Example 6: Formulation example / granules

 After mixing the composition shown in the following Table 8 with a mixer (PM-5W, manufactured by Kikusui Seisakusho), water is added and kneaded, followed by extrusion granulator (DOME GRAN, manufactured by Fuji Baudal) The mixture was turned into a column with a diameter of 0.8 mm and then sized, dried, and sieved to obtain granules. The granules are excellent in disintegration in the stomach and can be provided in a package form such as a sachet. Table 8 Composition of granules

 Component Weight (%)

 Indigestible dextrin 5 0

 Inventive Chitosan Induction 1 0

 Microcrystalline cellulose 20

 Hydroquinine propyl cellulose 5

 Corn Starch 1 0

 Total 100 cases Ί: Formulation example / tablet

Each component was mixed according to the composition shown in Table 9 below, and tablets having a diameter of 8 mm and a weight of 15 Omg were produced using a tableting machine (Collect 19K, manufactured by Kikusui Seisakusho). This tablet was excellent in tableting properties, hardness and disintegration in the stomach. Table 9 Composition of tablets

 Component Weight (%)

 Indigestible dextrin 5 0

 Chitosan derivative of the present invention 10

 Microcrystalline cellulose 2 9

 Cornstarch 1 0

 Talc

 Total 100 Example 8: Formulation examples / drinks

 A drink formulation having the composition shown in Table 10 below was produced as a trial. This drink was excellent in solubility and stability. Table 10 Drinks

 Component Weight (g)

 Indigestible dextrin 6 0

 Chitosan derivative of the present invention 10

 Glucose 1 0 0

 Fragrance 1

 1 volume with water

Claims

7 Scope of Claim 1. A chitosan derivative that can be obtained by partially deacetylating chitin and then reducing it.  2. The chitosan derivative according to claim 1, having a degree of deacetylation of 20 to 80%.  3. The chitosan derivative according to claim 1 or 2, wherein the average ^^ amount is 50,000 to 500,000.  4. The chitosan derivative according to claim 3, which is a compound represented by the following formula (I).

(I) (Wherein, n represents an integer of from 20 to 1,400, R represents a hydrogen atom or a group COCH _3, represents a group Rei_0 Ji? 1 ₃ 20-80% of all the R in the proviso).  5. A method for producing a chitosan derivative, comprising a step of partially deacetylating chitin, followed by a reduction treatment. 6. The production method according to claim 5, wherein the degree of deacetylation is 40 to 60%. 7. A composition comprising the chitosan derivative according to any one of claims 1 to 4.  8. The composition according to claim 7, further comprising a chitosan derivative represented by the formula (H).

(II) (Wherein, eta 2 0; represents an integer of L 4 0 0, R represents a hydrogen atom or a group C_〇 C Eta _3, except 2 0-8 0% group of all the R in the molecule Represents 0 0 ^ £ ₃ ).  9. The composition according to claim 7 or 8, which is a pharmaceutical composition or a food. 10. A pharmaceutical composition or food comprising the chitosan derivative according to any one of claims 1 to 4 or the composition according to claim 7 or 8 to f || g, and dietary fiber.  11. The pharmaceutical composition or food of claim 10, wherein the dietary fiber is indigestible dextrin.  12. The pharmaceutical composition according to claim 10 or 11, which has a constipation improving effect. 7 This is ¾i 'm ₀ 1 3. A method for treating constipation, comprising administering the chitosan derivative according to any one of claims 1 to 4 to an animal including a human. 14. The method of treating constipation according to claim 13, wherein dietary fiber is administered together. 15. The method of claim 14, wherein the dietary fiber is indigestible dextrin. 1 6. Use of the chitosan derivative according to any one of claims 1 to 4 for producing constipation 洽 ^^.