阅读说明：本技术 保湿外用剂 (Moisture-retaining external preparation ) 是由 石川稿太郎 柏村卓朗 加藤卓也 古贺徹 石川杰 于 2018-05-30 设计创作，主要内容包括：本发明提供一种保湿外用剂,其含有选自戊聚糖多硫酸酯和它们的药学上可接受的盐以及它们的药学上可接受的戊聚糖多硫酸酯的溶剂化物中的至少一种作为有效成分的新型保湿外用剂。因为本发明的保湿外用剂具有不含源自动物的组分的物质作为有效成分,其可以根据需要作为不含源自动物的组分的保湿外用剂来制造。(The present invention provides a novel moisturizing external preparation containing at least one selected from pentosan polysulfate, pharmaceutically acceptable salts thereof, and solvates of the pentosan polysulfate as an active ingredient. Since the moisturizing external preparation of the present invention has a substance free from an animal-derived component as an active ingredient, it can be produced as a moisturizing external preparation free from an animal-derived component as needed.)

1. A moisturizing external preparation comprising at least one selected from the group consisting of pentosan polysulfate, a pharmaceutically acceptable salt of pentosan polysulfate, and a pharmaceutically acceptable solvate thereof, as an effective ingredient.

2. The moisturizing external preparation according to claim 1, wherein the pentosan polysulfate has an uronic acid content of 0.0 to 15.0 mass%.

3. The moisturizing external preparation according to claim 2, wherein the pentosan polysulfate has an uronic acid content of 7.0 to 15.0 mass% and an acetyl group content of 0 to 2.0 mass%.

4. The moisturizing external preparation according to claim 2, wherein the pentosan polysulfate has an uronic acid content of 0.0 to 6.0 mass%.

5. The moisturizing external preparation according to any one of claims 1 to 4, comprising sodium pentosan polysulfate as a pharmaceutically acceptable salt of pentosan polysulfate.

6. The moisturizing external preparation according to any one of claims 1 to 5, wherein the dispersity of the pentosan polysulfate is 1.00 or more and 1.40 or less.

7. The moisturizing external agent according to any one of claims 1 to 6, which is an aqueous solution containing pentosan polysulfate, a pharmaceutically acceptable salt of pentosan polysulfate, and a pharmaceutically acceptable solvate thereof, in an amount of 0.05% by mass or more and 40% by mass or less with respect to the total mass of the moisturizing external agent.

Technical Field

The invention relates to a moisturizing external preparation.

Background

Generally, glycerin, propylene glycol, sorbitol, diethylene glycol monoethyl ether, and the like are known as humectants. Further, polysulfated mucopolysaccharides such as chondroitin sulfate are also used as moisturizers (for example, patent literature (PTL) 1). Polysulfated mucopolysaccharides such as chondroitin sulfate are known as heparinoids (heparin), and are extracted from organs of animals such as cattle and pigs.

Pentosan polysulfate is known as a substance that can be used as a substitute for heparin as a therapeutic agent for thrombosis, osteoarthritis, and the like (for example, patent literature (PTL) 2). Pentosan polysulfate can be obtained by sulfating xylo-oligosaccharides derived from plants.

Reference list

Patent document

PTL 1:JPS62-4362A

PTL 2:WO2010/000013

Disclosure of Invention

Problems to be solved by the invention

The invention aims to provide a novel moisturizing external preparation.

Means for solving the problems

Pentosan polysulfate is known as a heparin-substituting substance that can be used as a therapeutic agent for thrombosis, osteoarthritis, and the like. Since heparin is a substance derived from a specific animal, hesitation is caused in the case of being used as a moisturizer from the viewpoint of religious ethics and the like. Pentosan polysulfate can be manufactured from plant-derived raw materials; however, the moisturizing effect of pentosan polysulfate is unknown. Accordingly, the inventors have conducted intensive studies. As a result, the inventors found that pentosan polysulfate can exhibit excellent efficacy as a moisturizing external agent.

Specifically, the present invention provides the following [1] to [7 ].

[1] A moisturizing external preparation comprising at least one selected from the group consisting of pentosan polysulfate, a pharmaceutically acceptable salt of pentosan polysulfate, and a pharmaceutically acceptable solvate thereof, as an effective ingredient.

[2] The moisturizing external preparation according to [1], wherein the pentosan polysulfate has an uronic acid content of 0.0 to 15.0 mass%.

[3] The moisturizing external preparation according to [2], wherein the pentosan polysulfate has an uronic acid content of 7.0 to 15.0 mass% and an acetyl group content of 0 to 2.0 mass%.

[4] The moisturizing external preparation according to [2], wherein the pentosan polysulfate has an uronic acid content of 0.0 to 6.0 mass%.

[5] The moisturizing external preparation according to any one of [1] to [4], which comprises sodium pentosan polysulfate as a pharmaceutically acceptable salt of pentosan polysulfate.

[6] The moisture-retaining external preparation according to any one of [1] to [5], wherein the dispersity of the pentosan polysulfate is 1.00 or more and 1.40 or less.

[7] The moisturizing external agent according to any one of [1] to [6], which is an aqueous solution containing pentosan polysulfate, a pharmaceutically acceptable salt of pentosan polysulfate, and a pharmaceutically acceptable solvate thereof, in an amount of 0.05% by mass or more and 40% by mass or less with respect to the total mass of the moisturizing external agent.

From another viewpoint, the present invention further provides:

use of at least one member selected from the group consisting of pentosan polysulfate, pharmaceutically acceptable salts of pentosan polysulfate, and pharmaceutically acceptable solvates thereof;

use of at least one compound selected from pentosan polysulfate, pharmaceutically acceptable salts of pentosan polysulfate, and pharmaceutically acceptable solvates thereof, for the manufacture of a moisturizing external preparation; and

a method of moisturizing comprising administering at least one selected from the group consisting of pentosan polysulfate, a pharmaceutically acceptable salt of pentosan polysulfate, and a pharmaceutically acceptable solvate thereof, to the skin of a human or animal in an amount effective for moisturizing.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a novel moisturizing external preparation is provided. Since the moisturizing external preparation of the present invention includes a substance containing no animal-derived component as an active ingredient, the preparation can be produced as a moisturizing external preparation containing no animal-derived component as needed. In addition, the quality control of the external moisture-retaining agent of the present invention is relatively easy.

Drawings

Fig. 1 is a graph showing the water content of the stratum corneum before and after the application of the external preparation obtained in the example and comparative example.

Fig. 2 is a graph showing the relationship between the uronic acid content of pentosan polysulfate and the amount of 0.01N aqueous hydrochloric acid solution required to adjust the pH from pH 6 to pH 4.

Detailed Description

The present invention is described in detail below. Based on typical embodiments and specific examples, constituent features may be described below; however, the invention is not limited to such embodiments.

Moisture-retaining external preparation

The moisturizing external preparation (moisturizer) of the present invention comprises at least one selected from the group consisting of pentosan polysulfate, a pharmaceutically acceptable salt of pentosan polysulfate, and a pharmaceutically acceptable solvate of pentosan polysulfate or a pharmaceutically acceptable salt of pentosan polysulfate. In the present specification, pentosan polysulfate, a pharmaceutically acceptable salt of pentosan polysulfate, a pharmaceutically acceptable solvate of pentosan polysulfate and a pharmaceutically acceptable solvate of a salt of pentosan polysulfate may be collectively referred to as pentosan polysulfate.

The moisturizing external preparation of the present invention contains pentosan polysulfate as an active ingredient for moisturizing action. The phrase "comprising as an active ingredient" as used in this specification means comprising as an active ingredient, or comprising in an amount to provide an effect. That is, the external moisturizing agent of the present invention has at least a moisturizing effect. The moisturizing external preparation of the present invention can exhibit excellent moisturizing effects based on the contained pentosan polysulfate as an effective ingredient for moisturizing effects. The moisturizing external preparation can be used, for example, as an external preparation for maintaining the water content of the stratum corneum on the skin surface or as an external preparation for increasing the water content of the stratum corneum on the skin surface.

Pentosan polysulfate, which is an active ingredient of the moisturizing external preparation of the present invention, is known as an active ingredient of a medicament, such as a therapeutic agent for osteoarthritis (for example, PTL 2). The moisturizing external preparation of the present invention can have a pharmacological effect in addition to the moisturizing effect derived from the activity of pentosan polysulfate contained as an active ingredient. In addition, the moisturizing external preparation of the present invention may have a pharmacological effect derived from the activity of a component other than pentosan polysulfate, in addition to the moisturizing effect. For example, the moisturizing external preparation of the present invention may exhibit an anti-inflammatory effect, a skin aging suppression effect, a whitening effect, an anti-allergic effect, and the like, in addition to the moisturizing effect. When the moisturizing external preparation of the present invention exhibits, for example, an anti-inflammatory effect, the moisturizing external preparation of the present invention can be used as an anti-inflammatory external preparation (anti-inflammatory agent) having a moisturizing effect.

The moisturizing external preparation of the present invention can be applied to humans or animals (except humans). The moisturizing external preparation of the present invention is preferably applied to the skin or mucosa of a human or an animal, more preferably to the skin or mucosa of a human and even more preferably to the skin of a human.

The form of the external moisture-retaining agent is not particularly limited, and may be liquid, emulsion, gel, spray, mousse, or the like; the dosage form is preferably liquid. Specific examples of the moisturizing external preparation include various forms such as ointments, various cosmetic creams, emulsions, lotions, beauty essences, packs, lipsticks, foundation makeup, foundations, sun screens, bath lotions, jellies and aerosols. The moisturizing external preparation of the present invention is preferably in the form of a lotion.

When the moisturizing external preparation of the present invention is prepared in a liquid state, the moisturizing external preparation may be formed, for example, as an aqueous solution prepared by dissolving pentosan polysulfate in water. The moisturizing external preparation in the form of an aqueous solution preferably contains pentosan polysulfate in an amount of 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more, relative to the total mass of the moisturizing external preparation. On the other hand, the moisturizing external preparation contains pentosan polysulfate in an amount of 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, relative to the total mass of the moisturizing external preparation. When the pentosan polysulfate content of the moisturizing external preparation is within the above range, the moisturizing effect is more effectively exhibited.

The moisturizing external preparation of the present invention may further contain a component other than pentosan polysulfate as desired. Examples of such other components include glycerol, propylene glycol, sorbitol, diethylene glycol monoethyl ether, and polysulfated mucopolysaccharides such as chondroitin sulfate; other humectants; anti-inflammatory agents or cosmetic ingredients known to be added to external preparations or cosmetics; and the like. The moisturizing external preparation of the present invention may further include known components as additives for pharmaceuticals or cosmetics, such as an oily base, a surfactant, alcohols, a thickener, a gelling agent, an antioxidant, a preservative, a bactericide, a chelating agent, a pH adjuster, an ultraviolet absorber, a whitening agent, a solvent, a keratolytic agent, a dissolving agent, an antipruritic agent, an antiperspirant, a freshener, a reducing agent/oxidizing agent, a polymer powder, vitamins and/or derivatives thereof, saccharides and/or derivatives thereof, organic acids, inorganic powders, a perfume, a pigment, and a pigment. From the viewpoint of providing a moisturizing external preparation containing no animal-derived component, the moisturizing external preparation of the present invention preferably contains no animal-derived component; however, the preparation may contain components derived from animals depending on the purpose.

Pentosan polysulfate

Pentosan polysulfate has a structure in which at least one hydroxyl group of the xylooligosaccharide is sulfated. Pentosan polysulfate is preferably obtained by sulfating acidic xylo-oligosaccharides or neutral xylo-oligosaccharides, and more preferably by sulfating acidic xylo-oligosaccharides. Among xylooligosaccharides having a structure in which xylooligosaccharides are sulfated, neutral xylooligosaccharides are a group that does not contain uronic acid. Acidic xylo-oligosaccharides are of the type in which at least one uronic acid and at least one xylose unit are bound in one xylo-oligosaccharide molecule. That is, acidic xylo-oligosaccharide has at least one uronic acid residue as a side chain in one xylo-oligosaccharide molecule. The average number of uronic acid residues per molecule of acidic xylooligosaccharide is preferably 1 or more and 3 or less, more preferably 1 or more and 2 or less. The number of uronic acid residues contained in one xylo-oligosaccharide molecule can be measured by carbazole-sulfuric acid method or colorimetric method using sodium tetraborate. The uronic acid content (% by mass) of pentosan polysulfate, as described in the examples, is a value calculated from the number of uronic acid residues in a predetermined amount of pentosan polysulfate obtained by the carbazole-sulfuric acid process described above.

In this specification, pentosan polysulfate includes salts of pentosan polysulfate, solvates of pentosan polysulfate and solvates of salts of pentosan polysulfate. The salt of pentosan polysulfate is preferably a pharmaceutically acceptable salt; and examples include sodium pentosan polysulfate, potassium pentosan polysulfate, calcium pentosan polysulfate, and the like. The solvate is preferably a pharmaceutically acceptable solvate. Examples of solvates include water.

The pentosan polysulfate preferably has a structure represented by the following formula II.

In the general formula II, R each independently represents a hydrogen atom, -COCH₃or-SO₃X¹(ii) a And at least one R in the molecule of the pentosan polysulfate is-SO₃X¹。X¹Is a hydrogen atom, or a monovalent or divalent metal; and X¹Preferably a hydrogen atom, sodium, potassium, or calcium, more preferably sodium, potassium, or calcium, and particularly preferably sodium. X is a hydrogen atom, or a monovalent or divalent metal; and X is preferably a hydrogen atom, sodium, potassium, or calcium, more preferably sodium, potassium, or calcium, and particularly preferably sodium. n1 and n2 each independently represent an integer of 0 or more and 30 or less, and at least one of n1 and n2 is an integer of 1 or more.

In formula II, X is preferably a monovalent or divalent metal, and the compound is preferably a pharmaceutically acceptable salt of pentosan polysulfate. For example, X is preferably sodium, potassium, or calcium. In this case, the pentosan polysulfate salt is sodium pentosan polysulfate, potassium pentosan polysulfate or calcium pentosan polysulfate. Among these, sodium pentosan polysulfate is particularly preferred as the salt of pentosan polysulfate. The moisturizing external preparation preferably contains sodium pentosan polysulfate as a salt of pentosan polysulfate.

In the general formula II, n1+ n2 is preferably 1 to 90, more preferably 1 to 27, even more preferably 2 to 18, and particularly preferably 3 to 10.

One pentosan polysulfate molecule may contain one structure represented by formula II, or more than two structures represented by formula II. When one pentosan polysulfate molecule comprises more than two structures represented by formula II, the pentosan polysulfate preferably comprises said structures as structures representing repeating units. The pentosan polysulfate may be a structure represented by formula II, or may have a structure composed of only the structure represented by formula II as a repeating unit, or may further include other structural units. A structure represented by the general formula II or a structure composed of only the structure represented by the general formula II as a repeating unit is preferable.

Pentosan polysulfate preferably does not contain sugar units derived from arabinose (arabinofuranose residues).

The moiety that is a terminal of the structure represented by formula II and is not bonded to the structure represented by formula II may be — OR. That is, -OR may be bonded to the left terminal (n1 side) of formula II, and-R may be bonded to the right terminal (n2 side) of formula II. Particularly preferred is-OR^XBonded to the left terminal end (n1 side) of the formula II^XTo the right terminal (n2 side) of the formula II. In the general formula II, R^XIs a hydrogen atom or-SO₃X¹；X¹Is a hydrogen atom or a monovalent or divalent metal; and X¹Preferably a hydrogen atom, sodium, potassium, or calcium, more preferably sodium, potassium, or calcium, and particularly preferably sodium.

Pentosan polysulfate can be a mixture of individual molecules of the formula II which differ from one another by the value of n1, n2, the type of substituents R and/or the degree of substitution.

Pentosan polysulfate may contain a certain amount of uronic acid residues and acetyl (-COCH)₃) A xylose unit bonded thereto. For example, the acetyl group content of the pentosan polysulfate may be greater than 2.0 mass% and less than 6.0 mass%.

The pentosan polysulfate preferably has an acetyl group content of 0 to 2.0 mass%, preferably 0 to 1.0 mass%, more preferably 0 to 0.4 mass%, even more preferably 0 to 0.3 mass%. It is particularly preferred that the acetyl content of the pentosan polysulfate is substantially 0 mass%. represents-COCH₃The amount of R (a) is preferably 8% or less, more preferably 4% or less, even more preferably 1% or less of the total number of R in formula II. It is particularly preferred that none of R is-COCH₃. That is, it is particularly preferred that each R independently represents a hydrogen atom or-SO₃X。

In order to obtain a pentosan polysulfate having an acetyl group content of 0 to 2.0 mass%, the pentosan polysulfate is preferably produced by a deacetylation step described later.

When pentosan polysulfate has a low acetyl content, sodium pentosan polysulfate can be produced in high yield from acidic xylo-oligosaccharides.

The acetyl content of the pentosan polysulfate may be determined by¹The integral ratio of peaks in the H-NMR measurement was calculated. Specifically, first of all,¹H-NMR measurement with a composition containing a specific amount of pentosan polysulfate and a specific amount of an internal standard substance¹H-NMR measurement of the solution. In the obtained spectrum, the molar amount of acetyl group in the solution was obtained by comparing the integrated ratio of the peak of the specific group of the internal standard substance to the peak of acetyl group. The molar amount of acetyl groups was then multiplied by 43; and dividing the obtained value by the average molecular weight obtained separately to obtain the mass% of acetyl groups.

The weight average molecular weight (Mw) of the pentosan polysulfate is not particularly limited, and may be, for example, 4000 or less, 3900 or less, or 3800 or less. In this case, the pentosan polysulfate preferably has a weight average molecular weight (Mw) of 1000 or more, more preferably 1500 or more, even more preferably 2000 or more. The pentosan polysulfate may have a weight average molecular weight (Mw) of more than 4000, may be 5000 or more, may be 8000 or more, may be 10000 or more, may be 15000 or more, and may be 20000 or more. In this case, the weight average molecular weight (Mw) of the pentosan polysulfate is preferably 50000 or less, more preferably 45000 or less, even more preferably 40000 or less. The weight average molecular weight (Mw) of pentosan polysulfate may also be appropriately adjusted according to the desired efficacy of the moisturizing external preparation.

The number average molecular weight (Mn) of the pentosan polysulfate is not particularly limited, and may be, for example, 4000 or less, 3900 or less, 3800 or less, or 3750 or less. In this case, the lower limit of the number average molecular weight (Mn) of the pentosan polysulfate is preferably 1000.

The pentosan polysulfate may have a number average molecular weight (Mn) of 5000 or more, 7000 or more, 10000 or more, 15000 or more, or 20000 or more.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of pentosan polysulfate can be measured by GPC (gel permeation chromatography). As the GPC column, TSKgel G2000SWXL manufactured by Tosoh Corporation can be used. As the conditions of GPC, for example, the following conditions are used.

Eluent: 300mM sodium chloride/50 mM sodium acetate buffer (pH 4.0)

Flow rate: 1 mL/min

Measuring the temperature: 40 deg.C

A detector: differential refractive detector

Analysis time: 15 minutes

The dispersity of the pentosan polysulfate is preferably 1.00 or more and 1.40 or less, more preferably 1.00 or more and 1.35 or less. The dispersity of the pentosan polysulfate may be 1.05 or more, or may be 1.10 or more. The dispersity (D) of the pentosan polysulfate is calculated by the following formula.

Dispersity (D) ═ weight average molecular weight (Mw)/number average molecular weight (Mn)

By setting the dispersion degree of pentosan polysulfate within the above range, the moisturizing external preparation can more effectively exhibit various effects, such as a moisturizing effect.

In pentosan polysulfate, denotes-SO₃The number of R of X preferably represents more than 50%, more preferably more than 70%, even more preferably more than 90% of the total number of R in formula II.

The above proportions are not necessarily satisfied by individual molecules, but by pentosan polysulfate as an integral mixture of individual molecules.

The sulfur content of the pentosan polysulfate is preferably 10.0% by mass or more, more preferably 12.0% by mass or more, and even more preferably 15.0% by mass or more. The pentosan polysulfate preferably has a sulfur content of 20.0% by mass or less. Here, the sulfur content of pentosan polysulfate is a value determined according to the oxygen bottle combustion method described in japanese pharmacopoeia.

The content of uronic acid in the pentosan polysulfate is preferably 0.0 to 15.0 mass%. The values used herein to describe the uronic acid content do not have to be met by a single molecule but can be met by pentosan polysulfate as an integral mixture of single molecules.

In embodiments in which the pentosan polysulfate has a high uronic acid content, the pentosan polysulfate preferably has an uronic acid content of 7.0 mass% to 15.0 mass%, more preferably 7.5 mass% to 14.0 mass%, even more preferably 7.7 mass% to 13.0 mass%. In this embodiment, the pentosan polysulfate preferably has an acetyl group content of 0 to 2.0 mass%, more preferably 0 to 1.0 mass%, even more preferably 0 to 0.4 mass%, and particularly preferably 0 to 0.3 mass%. Most preferably, the pentosan polysulfate has an acetyl content of substantially 0 mass%. In this embodiment, the pentosan polysulfate preferably has a weight average molecular weight (Mw) of 5000 or less, and more preferably 4000 or less. Further, the number average molecular weight (Mn) is preferably 5000 or less, and more preferably 4000 or less.

As shown in examples described later, pentosan polysulfate having a high uronic acid content has a high pH buffering effect. Therefore, by using pentosan polysulfate having a high uronic acid content as an active ingredient of the moisturizing external preparation of the present invention, the pH of the moisturizing external preparation can be easily adjusted, for example, even if a pH adjuster or a pH buffer is not separately added or even if the amount of the pH adjuster or the pH buffer added is small.

The concentration of pentosan polysulfate in the aqueous solution for sufficiently exerting the pH buffering action is preferably 10 to 500mg/mL, and more preferably 50 to 300 mg/mL.

In embodiments in which the pentosan polysulfate has a low uronic acid content, the pentosan polysulfate preferably has an uronic acid content of 0.0 to 4.0 mass%, more preferably 0.0 to 2.0 mass%, even more preferably 0.0 to 1.0 mass%. It is particularly preferred that the pentosan polysulfate of the present invention has an uronic acid content of substantially 0.0 mass%.

Specifically, the pentosan polysulfate may have a structure represented by formula I.

In the general formula I, R independently represents a hydrogen atom, -COCH₃or-SO₃X; at least one R in the molecule being-SO₃X; x is a hydrogen atom or a monovalent or divalent metal; and n represents an integer of 1 or more and 30 or less.

The compound represented by the general formula I is preferably represented by the following general formula I^XThe compound shown in the specification. More specifically, the terminal R is preferablyIs not-COCH₃。

In the general formula I^XIn, R^XEach independently represents a hydrogen atom or-SO₃X。

As shown in the examples described later, when sodium pentosan polysulfate has a low uronic acid content, sodium pentosan polysulfate powder can be produced from xylo-oligosaccharide powder with high yield. Further, sodium pentosan polysulfate in the form of an aqueous solution is less prone to yellowing even after long-term storage at high temperatures. Therefore, by using pentosan polysulfate having a low uronic acid content as an active ingredient of the moisturizing external preparation of the present invention, a moisturizing external preparation that is less likely to discolor can be obtained.

Process for producing pentosan polysulfate

Pentosan polysulfate can be obtained by a process for the manufacture of pentosan polysulfate, for example comprising: a step 1 of obtaining xylooligosaccharides (acidic xylooligosaccharides, neutral xylooligosaccharides, or a mixture of these xylooligosaccharides) from a plant-derived raw material; and a step 2 of obtaining pentosan polysulfate from xylo-oligosaccharides. The 1 st step includes a step of depolymerizing a plant-derived raw material. Pentosan polysulfate can be efficiently produced by sequentially performing a step of depolymerizing a plant-derived raw material and a sulfation step. This can increase the yield of pentosan polysulfate; and also can reduce the production cost of pentosan polysulfate, thereby providing pentosan polysulfate more inexpensively.

Neutral xylo-oligosaccharides can be produced by polymerizing D-xylose.

The process for producing pentosan polysulfate may further comprise a deacetylation step. By including a deacetylation process, pentosan polysulfate with a low acetyl content can be produced.

The average degree of polymerization of the sulfated xylooligosaccharides is preferably adjusted appropriately according to the molecular weight of the pentosan polysulfate obtained in the final product.

The average polymerization degree of xylooligosaccharide can be calculated by dividing the total sugar amount of xylooligosaccharide by the reducing sugar amount. In the calculation of the total sugar amount, first, the xylo-oligosaccharide solution was kept at 50 ℃ and centrifuged at 1500rpm for 15 minutes. Thereafter, the total sugar content of the supernatant was quantified by the phenol-sulfuric acid method ("Kangento no Teriyo-Ho (method for quantifying reducing sugar); published by the academic Press center). A calibration curve used for quantification was prepared using D-xylose (Wako pure chemical industries). The amount of reducing sugar was quantified using Somogyi-Nelson method ("Kangento no Terryo-Ho (method for quantifying reducing sugar); issued by the academic Press center). A calibration curve used for this quantification was also prepared using D-xylose (Wako pure chemical industries).

Plant-derived material

In the present invention, xylo-oligosaccharides (acidic xylo-oligosaccharides or neutral xylo-oligosaccharides, or a mixture of these xylo-oligosaccharides) can be obtained by depolymerizing a plant-derived raw material. Examples of plant-derived materials include wood-derived materials, seed-derived materials, grain-derived materials, fruit-derived materials, and the like. Further, the plant-derived material includes cotton such as cotton linter and cotton lint; such as kenaf, hemp, ramie, rice straw, and other herbaceous plants. As the plant-derived raw material, the above-mentioned raw materials derived from various sources may be used in combination.

Among them, a raw material derived from wood is preferably used as the raw material derived from a plant. Examples of wood-derived raw materials that can be used include coniferous trees, hardwood trees, or wood-like raw materials. The raw material derived from wood is preferably at least one selected from coniferous trees and broadleaf trees; and more preferably broadleaf trees are used. The wood-derived feedstock may be a mixture of coniferous and broadleaf trees. Bark may also be used as a raw material derived from wood.

Examples of broad-leaved trees include beech, eucalyptus globulus, eucalyptus grandis, eucalyptus urophylla, eucalyptus pellita, eucalyptus fusceolata, acacia negra, and the like. Examples of conifers include cedar, cypress, pine, cypress, hemlock, and the like.

The raw material derived from wood preferably has a specific gravity of 450kg/m³Above and 700kg/m³Below, and more preferably 500kg/m³Above 650kg/m³The following. By setting the specific gravity of the raw material derived from wood within the above range, the production efficiency of xylooligosaccharide can be further improved.

The raw material derived from wood is preferably wood pieces (woodchips) obtained by crushing one or more of the above-mentioned woods. By using wood chips as the plant-derived raw material, depolymerization of the plant-derived raw material can be efficiently performed, and the production efficiency of xylooligosaccharide can be improved.

Step 1 of

Depolymerization step

The method for producing pentosan polysulfate comprises a step 1 of depolymerizing a plant-derived raw material to obtain xylooligosaccharides. The step of depolymerizing the plant-derived raw material is a step of chemically and/or physically decomposing the plant-derived raw material to produce xylooligosaccharides. Examples of the chemical and/or physical decomposition step include a heat treatment step, an alkali treatment step, an acid treatment step, an enzyme treatment step, an ionic liquid treatment step, a catalyst treatment step, and the like. Among these steps, the depolymerization step is preferably at least one selected from the group consisting of a heat treatment step, an alkali treatment step, an acid treatment step and an enzyme treatment step; and a heat treatment process is more preferable. The heat treatment step may be a heat and pressure step. The depolymerization step is preferably carried out under non-alkaline conditions (pH 9 or less, preferably pH8 or less).

The heat treatment step is a step of heating the plant-derived material in the presence of a solution. In such a heat treatment step, the plant-derived material is hydrolyzed, and thus the heat treatment step may be a hydrolysis treatment step or a pre-hydrolysis treatment step. The solution used in the heat treatment step is preferably water. The ratio (mass ratio) of water to the plant-derived raw material is preferably in the range of 1:1 to 1: 10. By setting the ratio of water to the plant-derived raw material within the above range, the hydrolysis reaction can be efficiently performed. The water used in the heat treatment step may be water added separately from the plant-derived raw material; or a portion of the water may be the moisture originally contained in the plant-derived material.

In the heat treatment step, other chemicals may be added in addition to the plant-derived material and water. Examples of such other drugs include bases, acids, and chelating agents. Further, a chemical such as a scale inhibitor, a resin control agent (pitch control agent), and an ionic liquid may be added to assist the depolymerization of the polysaccharide directly or indirectly.

The heat treatment step is a step of heating a plant-derived material in the presence of water. The heating temperature (liquid temperature) in this step is preferably 30 ℃ or higher, more preferably 50 ℃ or higher, even more preferably 75 ℃ or higher, still even more preferably 90 ℃ or higher, particularly preferably 100 ℃ or higher, and most preferably 120 ℃ or higher. On the other hand, the heating temperature (liquid temperature) is preferably 300 ℃ or less, more preferably 250 ℃ or less, even more preferably 200 ℃ or less.

The treatment time in the heat treatment step can be appropriately determined depending on the treatment temperature. The treatment time is, for example, preferably 5 minutes or more, more preferably 10 minutes or more, and even more preferably 20 minutes or more. The P-factor represented by the following formula is the product of the heat treatment temperature and the heat treatment time. The P factor is preferably adjusted to be within the preferred range.

In the above formula, P represents a P factor, T represents an absolute temperature (. degree. C. +273.5), T represents a heat treatment time, and K represents_H1(T)/K_100℃Indicating the relative rate of hydrolysis of the glycosidic bond.

In the heat treatment step, the P-factor is preferably 200 or more. More preferably 250 or more, even more preferably 300 or more. On the other hand, the P-factor is preferably 1000 or less. In the heat treatment process, the P factor is appropriately adjusted so that the average polymerization degree of xylooligosaccharide is within a desired range, and the molecular weight of the obtained pentosan polysulfate can be thereby adjusted.

In the heat treatment step, the pH of the solution containing the plant-derived material is preferably pH 9 or less, more preferably pH8 or less, and even more preferably pH 7 or less. That is, the heat treatment step is preferably performed under non-alkaline conditions. The pH value is the pH of the solution before the heat treatment step.

In the heat treatment process, the acid derived from the raw material may be dissociated, and the acid hydrolysis may be at least partially performed. Examples of acids derived from plant materials include organic acids such as acetic acid and formic acid. In this case, the pH of the solution containing the plant-derived raw material after acid hydrolysis is further lowered.

The process for producing pentosan polysulfate preferably includes a heat treatment step as an initial step. This can improve the production efficiency of xylooligosaccharide and further improve the production efficiency of pentosan polysulfate. By providing the heat treatment step as the initial step, the number of steps required for obtaining xylo-oligosaccharide can be significantly reduced in comparison with conventional methods. By providing the heat treatment process under non-alkaline conditions as the initial process, the manufacturing process can efficiently produce xylooligosaccharide with suppressed coloration because xylooligosaccharide is not substituted by hexenuronic acid.

The depolymerization step is preferably a heat treatment step, but may be a step other than the heat treatment step. For example, when the depolymerization step is an enzyme treatment step, the depolymerization step includes a step of mixing a plant-derived material with an enzyme. Examples of enzymes that can be used include hemicellulases and the like. Specific examples include commercially available Enzyme preparations such as Cellulosin HC100 (trade name, manufactured by HBIEnzymes Inc.), Cellulosin TP25 (trade name, manufactured by HBI Enzymes Inc.), CellulosinHC (trade name, manufactured by HBI Enzymes Inc.), Cartazyme (trade name, manufactured by Clariant AG), Ecopulp (trade name, manufactured by Rohm Enzyme GmbH), Sumizyme (trade name, manufactured by Shin Nihon chemical corporation), Pulpzyme (manufactured by Novo Nordisk), and Multifect 720 (Gene); and xylanases produced by microorganisms belonging to the genera Trichoderma (Trichoderma), Thermomyces (Thermomyces), Aureobasidium (Aureobasidium), Streptomyces (Streptomyces), Aspergillus (Aspergillus), Clostridium (Clostridium), Bacillus (Bacillus), Thermomyces (Thermotoga), Thermoascus (Thermoascus), Thermomyces (Caldocellum), Thermomonospora (Thermomonospora), and the like.

In the enzyme treatment step, an enzyme is added to a solution prepared by mixing a plant-derived raw material with water. The temperature of the solution during this treatment is preferably 10 ℃ or more and 90 ℃ or less, and more preferably 30 ℃ or more and 60 ℃ or less. The temperature of the solution is preferably a temperature close to the optimum temperature of the enzyme used. The pH of the solution is also preferably adjusted to a range in which the activity of the enzyme is increased, and for example, the pH of the solution is preferably adjusted to a pH of 3 or more and a pH of 10 or less.

When the depolymerization step is an alkali treatment step or an acid treatment step, the depolymerization step includes a step of mixing the plant-derived material with an alkali solution or an acid solution. In the alkali treatment step, sodium hydroxide or potassium hydroxide is preferably added. In the acid treatment step, hydrochloric acid, sulfuric acid, acetic acid, or the like is preferably added. In the above case, heating or pressing may be appropriately performed.

When the depolymerization step is at least one selected from the group consisting of an enzyme treatment step, an alkali treatment step and an acid treatment step, the production method may further include a pressing step, an extraction step, a heating step, a filtration step, a separation step, a purification step, a concentration step, a desalting step, or the like after the treatment step. The method may further include a step of reducing the molecular weight after the treatment step. Examples of other processes include the process described in JP2003-183303a, the contents of which are incorporated herein by reference.

Filtration step

In the method for producing pentosan polysulfate, the 1 st step may further include a filtration step after the depolymerization step. In the filtration step, the reaction mixture is separated into a solid component of the plant-derived raw material and a solution other than the solid component. More specifically, by providing a filtration step after the depolymerization step, the reaction product is separated into a filtrate and a solid component serving as a raw material of slurry. The solid content used as the pulp raw material is subjected to a digestion step or the like as a subsequent step to provide a cellulose raw material (dissolving pulp).

The recovered filtrate may be separated into a gas layer and a liquid layer. Since the gas layer contains a large amount of furfurals, these furfurals can be recovered and separated. In another aspect, the liquid layer comprises a plurality of hemicellulose comprising acidic xylo-oligosaccharides and neutral xylo-oligosaccharides. In the step described later, the acidic xylooligosaccharide or the neutral xylooligosaccharide contained in the liquid layer can be separated and purified.

Separation and purification step

In the method for producing pentosan polysulfate, the 1 st step may further include a separation and purification step after the depolymerization step. When the 1 st step includes the above-mentioned filtration step, the separation and purification step is preferably provided after the filtration step.

The 1 st step may further comprise a separation and purification step following the depolymerization step. However, the 1 st step is preferably provided with a filtration step after the depolymerization step; and a step of separating the desired xylooligosaccharide from the obtained filtrate and purifying the xylooligosaccharide. The filtration step may be provided as a part of the separation and purification step, or may be provided as a step separate from the separation and purification step. The separation and purification step is a step of separating and purifying acidic xylooligosaccharide or neutral xylooligosaccharide. Since the filtrate obtained in the filtering step contains acidic xylooligosaccharide and neutral xylooligosaccharide, the separation and purification step is also a step of sorting acidic xylooligosaccharide or neutral xylooligosaccharide.

In the separation and purification step, for example, ion exchange chromatography, affinity chromatography, gel filtration, ion exchange treatment, NF membrane treatment, UF membrane treatment, RO membrane treatment, activated carbon treatment, and the like are preferably used. In the separation and purification step, it is also preferable to carry out the separation and purification step by a combination of the above-mentioned methods. Wherein, ion exchange chromatography can be carried out in the separation and purification process, so as to selectively separate and purify the acidic xylooligosaccharide or the neutral xylooligosaccharide. For example, in ion exchange chromatography, acidic xylo-oligosaccharides are adsorbed, thereby obtaining neutral xylo-oligosaccharides from the non-adsorbed fraction. Specifically, the sugar solution is first treated with a strong cation exchange resin to remove metal ions from the sugar solution. Subsequently, sulfate ions and the like are removed from the sugar solution using a strong cation exchange resin. The resulting sugar solution was treated with a weak anion exchange resin to adsorb the acidic xylo-oligosaccharide on the resin. Neutral xylo-oligosaccharide was obtained from the unadsorbed fraction. In another aspect, the acid oligosaccharide is adsorbed to the resinWith low-concentration salt (NaCl, CaCl)₂、KCl、MgCl₂Etc.) to obtain an acidic xylo-oligosaccharide solution containing a small amount of impurities.

Concentration step

In the method for producing pentosan polysulfate, the 1 st step may further include a concentration step. The concentration step is preferably provided after the filtration step and before the separation and purification step, for example. By providing such a concentration step, the separation and purification step can be performed more efficiently, and the production efficiency of pentosan polysulfate can be improved.

Examples of the concentration step include a membrane treatment step using an NF membrane, an ultrafiltration membrane, a reverse osmosis membrane, or the like; a concentration step using evaporation or the like; and the like.

In the concentration step, the solution is concentrated so that the desired content of xylooligosaccharide is preferably 10% or more and 80% or less, and more preferably 20% or more and 60% or less, with respect to the total mass of the concentrated solution.

Dehydration step

The xylo-oligosaccharide obtained in the 1 st step may be in the form of a xylo-oligosaccharide solution. The xylo-oligosaccharide can also be obtained in the form of a xylo-oligosaccharide concentrate or xylo-oligosaccharide powder by performing a dehydration process. When xylo-oligosaccharide powder is produced, the production method preferably further comprises a powdering step after the separation and purification step. By providing the dehydration step in the present invention, sulfation in the sulfation step described later can be efficiently performed.

In the powdering step, the xylooligosaccharide solution obtained in the separation and purification step is treated with, for example, a spray dryer, a freeze dryer, a hot air dryer, a water-soluble organic solvent, or the like to obtain xylooligosaccharide powder.

Step 2

Sulfation process

In a 2 nd step, the xylo-oligosaccharides obtained in the 1 st step are sulfated to obtain pentosan polysulfate. That is, the 2 nd step includes a sulfation step.

In the sulfation step, sulfuric acid or a sulfuric acid derivative is added to the xylooligosaccharide solution to sulfate the xylooligosaccharide. Examples of the sulfuric acid derivative include sulfur trioxide pyridine complex, chlorosulfonic acid, and the like. In this step, the concentration of the xylo-oligosaccharide solution is preferably 0.1 mass% or more and 20 mass% or less, and it is preferable to add sulfuric acid to the xylo-oligosaccharide solution having such a concentration so as to achieve a concentration of 0.1 mass% or more and 50 mass% or less. The pH of the xylooligosaccharide solution after addition of sulfuric acid is preferably 1 or more and 9 or less.

Post sulfation purification procedure

In the method for producing a pentosan polysulfate, the 2 nd step may further include a post-sulfation purification step after the sulfation. By providing such a post-sulfation purification step, a high-purity pentosan polysulfate can be obtained.

In the post-sulfation purification step, a method such as centrifugation, membrane filtration, dialysis, treatment with a water-soluble organic solvent, or treatment with activated carbon is preferably used. Among them, the treatment with a water-soluble organic solvent and the treatment with activated carbon are preferable because the sulfated pentosan polysulfate can be selectively separated and purified.

Powdering step

In the 2 nd process, the sulfated pentosan polysulfate may be obtained in the form of a solution of pentosan polysulfate or in the form of powder of pentosan polysulfate produced by performing a powdering process. When producing the pentosan polysulfate powder, the production method preferably further comprises a powdering step after the post-sulfation purification step.

As the powdering step, for example, the pentosan polysulfate solution obtained in the post-sulfation purification step may be treated with a spray dryer, a freeze dryer, a hot air dryer, a water-soluble organic solvent, or the like to obtain a pentosan polysulfate powder.

Deacetylation step

In the production of pentosan polysulfate, deacetylation may be carried out. The deacetylation step is preferably performed at any stage after the depolymerization step. The deacetylation step reduces the acetyl content of the pentosan polysulfate. Specifically, the deacetylation step is a step of adding an alkali to a solution containing a substance obtained from a plant-derived raw material such as xylo-oligosaccharide (also referred to herein as "a solution containing xylo-oligosaccharide or the like") so as to adjust the solution to pH 11 or more. In the deacetylation step, the solution obtained after the depolymerization, the filtrate obtained by the filtration step, the solution containing xylooligosaccharide after the separation and purification step and before the sulfation step, the solution containing xylooligosaccharide (pentosan polysulfate) after the sulfation step, and the like may have a pH of 11 or more. Among these solutions, when the solution containing xylooligosaccharide after the separation and purification step and before the sulfation step is adjusted to pH 11 or more, pentosan polysulfate having stable quality and reduced acetyl content can be obtained, and the portion bonded with acetyl group can also be sulfated. Therefore, the sulfation efficiency and the production efficiency of pentosan polysulfate can be improved. When the solution containing xylooligosaccharide (pentosan polysulfate) obtained after the sulfation step is adjusted to pH 11 or more, the purification step can be performed more efficiently. The solution containing xylooligosaccharide or the like is preferably an aqueous solution. The solution containing xylo-oligosaccharide in this specification may also be referred to as xylo-oligosaccharide solution.

The pH in the deacetylation step is preferably 11 to 14, more preferably 12 to 13. The solution subjected to the deacetylation step is preferably maintained at pH 11 or more for 0.5 hours or more, more preferably at pH 11 or more for 1.0 hours or more, even more preferably at pH 11 or more for 2.0 hours or more, and particularly preferably at pH 11 or more for 3.0 hours or more. Particularly, when the pH is less than 12, the solution is preferably maintained for 1.0 hour or more. Particularly preferred conditions may be, for example, a condition of maintaining at pH 12 to 13 for 3 hours or more.

While maintaining the solution within the above pH range, it is preferable to stir the solution. The temperature used when the solution is maintained in the above pH range is not particularly limited, and room temperature is preferred.

In the deacetylation step, an alkali may be added to the solution (solution containing xylooligosaccharide or the like) subjected to the deacetylation step. The base to be added is not particularly limited as long as the desired pH can be achieved. The base is preferably sodium hydroxide.

The deacetylation step may include a pH adjustment step of adjusting the pH of a solution having a pH of 11 or more, which is obtained by maintaining the pH at the above pH and then adding a base, to a pH of less than pH 11. In the pH adjustment step, the pH of the solution may be adjusted to, for example, pH 9 or less, pH8 or less, pH 7 or less, pH 6 or less, pH 5 or less, pH 4 or less, or the like. The adjustment can be carried out by adding an acid. Examples of useful acids include hydrochloric acid.

The deacetylation step preferably includes a desalting step after the pH adjustment step. The salts obtained can be removed using, for example, dialysis membranes or NF membranes.

The deacetylation procedure may further comprise powdering the product obtained for subsequent treatment.

Other procedures

Molecular weight adjusting step

The method for producing a pentosan polysulfate may further comprise a molecular weight adjusting step between the 1 st step and the 2 nd step. FIG. 2 is a flowchart including a molecular weight adjusting step between the 1 st step and the 2 nd step. As shown in fig. 2, in the molecular weight adjusting step, the molecular weight of the xylooligosaccharide obtained in the 1 st step is adjusted. For example, in the molecular weight adjustment step, the molecular weight of xylooligosaccharide can be reduced.

In the molecular weight adjusting step, for example, acid treatment, alkali treatment, enzyme treatment, NF membrane treatment, UF membrane treatment, RO membrane treatment, gel filtration treatment, activated carbon treatment, ion exchange treatment, electrodialysis treatment, etc. may be performed to obtain pentosan polysulfate having a desired weight average molecular weight. Further, in the molecular weight adjustment step, a method including performing a film treatment or the like to selectively recover pentosan polysulfate having a desired weight average molecular weight may also be used.

Separation and purification process after molecular weight adjustment

The method for producing a pentosan polysulfate may further comprise a separation and purification step after the molecular weight adjustment step. Examples of the separation and purification step after molecular weight adjustment may include gel filtration, ion exchange treatment, NF membrane treatment, UF membrane treatment, RO membrane treatment, electrodialysis treatment, activated carbon treatment, water-soluble organic solvent treatment, chromatography treatment, and the like. When the production method comprises such a separation and purification step after molecular weight adjustment, xylooligosaccharide having a desired molecular weight obtained in the molecular weight adjustment step can be selectively recovered, and pentosan polysulfate having a narrow molecular weight distribution can be efficiently obtained.