JP7081792B2 - Electrostatic Complex and Organogels - Google Patents

Description

The present invention relates to an electrostatic complex capable of forming an organogel containing an organic solvent and the organogels.

A gel is a colloidal dispersion that loses its fluidity and becomes a jelly, and a gel that contains water as a dispersion medium is called a hydrogel. Some hydrogels can contain a large amount of water inside, and are widely used as water-absorbent materials for diapers as well as foods.

On the other hand, those containing an organic solvent as a dispersion medium are called organogels, and since they can include an organic solvent, they are attracting attention in the fields of energy, electronics, environmental industry, and the like. However, the number of research examples of organogels is overwhelmingly smaller than that of hydrogels, and they are in the developing stage, and the number of development examples is limited.

For example, the water-absorbent material of omtu is a crosslinked acrylic acid polymer, whereas the dispersoids constituting the organogels are mostly associative low-molecular-weight compounds as disclosed in Patent Document 1. Gels composed of low-molecular-weight compounds still have physical problems to be solved, such as improvement of toughness, and the application of high-molecular-weight substrates such as those used in hydrogels is expected. In addition, many natural substances are water-soluble, and as fat-soluble substances, there are many petroleum-derived substances and synthetic compounds, but the idea is to use a naturally-derived polymer base material as the dispersoid of organogels. The current situation is that it has not even reached the stage.

As a naturally occurring polymer compound, for example, there is polylysine obtained by dehydrating and condensing the amino acid lysine. Lysine has an α-amino group and an ε-amino group, but chemically synthesized polylysine is a polyα in which an α-amino group and an α-carboxy group, which are more reactive than the two amino groups, are reacted. Lysine. For example, Patent Documents 2 to 5 describe a mixture containing polylysine and sodium lauryl sulfate, but since this mixture is a micelle solution, the polylysine used is polyα-lysine.

On the other hand, it has been found that a bacterium belonging to the genus Streptomyces produces polyεlysine formed by a reaction between an α-carboxy group and an ε-amino group of lysine (Patent Document 6).

Japanese Unexamined Patent Publication No. 2013-104062 Special Table 2002-532536 Publication No. Special Table 2003-525891 Special Table 2003-533469 Gazette Japanese Unexamined Patent Publication No. 2012-6934 Special Publication No. 59-20359

As mentioned above, there are few research examples of organogels, and it can be said that there are even fewer research examples of organogels containing polymer compounds and naturally derived compounds as dispersoids.
Therefore, it is an object of the present invention to provide an electrostatic complex which is composed of a naturally-derived polymer compound and can form an organogel containing an organic solvent, and an organogel formed from the electrostatic complex. ..

The present inventors have conducted extensive research to solve the above problems. As a result, they have found that an organogel can be formed from an electrostatic complex of polyεlysine, which is a naturally derived polymer base material, and a specific anionic surfactant, and completed the present invention.
Hereinafter, the present invention will be shown.

[1] An electrostatic complex comprising polyεlysine and an anionic surfactant having a sulfonic acid group.
[2] The electrostatic complex according to the above [1], wherein the anionic surfactant is a sulfate ester type anionic surfactant.
[3] The electrostatic complex according to the above [1] or [2], wherein the ratio of the anionic surfactant to the α-amino group contained in the polyεlysine is 0.9 times the molar amount or more.
[4] The electrostatic complex according to any one of the above [1] to [3], wherein L-lysine accounts for 90% or more of the lysines constituting the polyε lysine.
[5] An organogels comprising the electrostatic complex according to any one of the above [1] to [4] and an organic solvent.
[6] The organogels according to the above [5], wherein the organic solvent is chloroform.
[7] The organogels according to the above [5], wherein the organic solvent is ethanol and / or isopropanol.
[8] A method for absorbing an organic solvent, which is a method for absorbing an organic solvent.
A step of preparing an electrostatic complex containing polyεlysine and an anionic surfactant having a sulfonic acid group, and
A method comprising a step of adding the organic solvent to the electrostatic complex.
[9] The method according to [8] above, wherein the anionic surfactant is a sulfate ester type anionic surfactant.
[10] The method according to the above [8] or [9], wherein the ratio of the anionic surfactant to the α-amino group contained in the polyεlysine is 0.9 times the molar amount or more.
[11] The method according to any one of the above [8] to [10], wherein the proportion of L-lysine among the lysines constituting the polyε lysine is 90% or more.
[12] The method according to any one of [8] to [10] above, wherein the electrostatic composite absorbs the organic solvent to form an organogel.
[13] The method according to any one of [8] to [12], wherein the organic solvent is chloroform.
[14] The method according to any one of [8] to [12], wherein the organic solvent is ethanol and / or isopropanol.

Since the electrostatic complex according to the present invention contains polyεlysine, which is a naturally occurring polymer compound, as a constituent component, it can be said that it is relatively environmentally friendly. Further, the electrostatic complex according to the present invention can include an organic solvent to form an organogel, and can further include a fat-soluble useful compound. Such an organogel may contain, for example, water-insoluble chlorophyll or pheophytin to exert its function, or may include a membrane protein while maintaining its higher-order structure to exert its function. be. Therefore, the electrostatic complex and organogels according to the present invention have extremely high industrial utility value as new materials that have never existed in the past.

FIG. 1 is a graph showing changes over time in the amount of chloroform when the chloroform-containing organogels and chloroform alone according to the present invention are left in an open system. FIG. 2 is an external photograph of the chlorophyll-containing organogels according to the present invention. (A) is an external photograph immediately after organogels preparation, (b) is an external photograph after the organogels are allowed to stand in a dark place, and (c) is an external photograph after the organogels are allowed to stand in a bright place. ..

The electrostatic complex according to the present invention contains polyεlysine and an anionic surfactant having a sulfonic acid group.

Polyεlysine is a polymer having the following repeating units, and has the same chemical structure as nylon 6 except that it has an α-amino group in the side chain.

The absolute structure of the lysine forming the polyε-lysine is not particularly limited, and for example, there are those consisting only of L-lysine, those consisting only of D-lysine, and those containing both, but any of them can be used. However, since the larger the ratio of one is, the better the stereoregularity and the higher the strength can be, polyεlysine consisting only of L-lysine and polyεlysine consisting only of D-lysine are preferable, and only L-lysine is used. Polyεlysine is more preferred. Furthermore, polyεlysine composed of L-glutamic acid is excellent in biodegradability. Specifically, it is preferable that 90 mol% or more of the lysine constituting the polyε lysine is L-lysine. As the ratio, 95 mol% or more is more preferable, 98 mol% or more or 99 mol% or more is further preferable, and substantially 100 mol% is particularly preferable.

The molecular size of the polyεlysine used is also not particularly limited, but for example, the degree of polymerization can be 15 or more and 700 or less, and the number average molecular weight can be 2000 or more and 100,000 or less. When the degree of polymerization is 15 or more or the number average molecular weight is 2000 or more, the gel is more easily formed. On the other hand, when the degree of polymerization is 700 or less or the number average molecular weight is 100,000 or less, water solubility can be more reliably ensured, and the electrostatic complex according to the present invention can be easily synthesized.

As described above, polyα-lysine is obtained by chemically dehydrating and condensing lysine. Therefore, as the polyεlysine, it is preferable to use one produced by microbial fermentation in the process. Polyεlysine produced by microbial fermentation is cheaper and more readily available than chemically synthesized products. Examples of the microorganism that produces polyεlysine include Streptomyces albulus and a polyεlysine-producing bacterium belonging to Streptomyces noursei. Poly-ε-lysine can generally be isolated and purified from the medium of poly-ε-lysine-producing bacteria.

The electrostatic complex according to the present invention contains an anionic surfactant containing a sulfonic acid group. Presumably, the side chain α-amino group of each lysine constituting the polyε lysine and the sulfonic acid group of the anionic surfactant are bound by electrostatic interaction and are insoluble in water. In the present invention, the "sulfonic acid group" includes a sulfate group (-OSO ₃ H or -OSO _3- ⁾ in addition to a so ^- called sulfonic acid group (-SO ₃ H or -SO _3- ).

Examples of the anionic surfactant containing a sulfonic acid group include branched chain alkylbenzene sulfonate (ABS), linear alkylbenzene sulfonate (LAS), alpha olefin sulfonate (AOS), and alkyl sulfate (AS). , Alkyl ether sulfate sodium (AES), dialkyl sulfosuccinate, lignin sulfonate and the like.
Branched chain alkylbenzene sulfonate (ABS) is a surfactant in which a sulfonic acid base such as a sodium sulfonate group is substituted in the branched chain alkylbenzene which is a hydrophobic portion, and for example, sodium 5-dodecylbenzene sulfonate is used. Can be mentioned.

Linear alkylbenzene sulfonate (LAS) is a surfactant in which a sulfonic acid base such as a sodium sulfonate group is substituted with linear alkylbenzene which is a hydrophobic moiety, and is based on branched-chain alkylbenzene sulfonate (ABS). Since foam pollution has become a problem, it is consumed in large quantities in place of ABS. Examples of LAS include sodium 1-dodecylbenzenesulfonate.

Alpha-olefin sulfonate (AOS) is a surfactant in which a long-chain alkenyl group, which is a hydrophobic moiety, is substituted with a sulfonic acid base. Examples of AOS include sodium 1-tetradecenesulfonate, sodium hexadecenesulfonate, sodium 3-hydroxyhexadecyl-1-sulfonate, sodium octadecene-1-sulfonate, and sodium 3-hydroxy-1-octadecansulfonate. be able to.

Alkyl sulfate (AS) is a salt of an ester of a higher alcohol and sulfuric acid. Since AS has a weaker protein denaturing effect than LA and has the highest biodegradability next to higher fatty acid salts (soap), it is blended in kitchen detergents, shampoos, dentifrices and the like. As AS, sodium dodecyl sulfate can be mentioned.
Alkyl ether sulfate sodium (AES) has a structure in which a polyalkylene glycol chain is sandwiched between an alkyl group of AS and a sulfate base.

The dialkyl sulfosuccinate is a surfactant in which the succinic acid of the dilong alkyl ester of succinic acid is replaced with a sulfonic acid group, and examples thereof include dioctyl sulfosuccinate (DSS).
Lignin sulfonate is a surfactant in which a sulfonic acid group is bonded to a lignin decomposition product. Lignin is a high molecular weight compound in which phenol compounds are bonded to each other, and a lignin decomposition product is a compound in which lignin is decomposed to reduce the molecular weight.

As the electrostatic composite according to the present invention, one in which polyεlysine is sufficiently modified with a sulfonic acid group-containing anionic surfactant is preferable because of its gelling ability. More specifically, the proportion of the sulfonic acid group-containing anionic surfactant constituting the electrostatic complex is 0.50 times by mole or more with respect to the side chain α-amino group of the lysine constituting the polyε lysine. It is preferably 0.60 times or more, more preferably 0.70 times or more or 0.80 times or more, and more preferably 0.90 times or more or 0.95 times or more. More preferably, 0.98 times mol or more is particularly preferable. An electrostatic composite containing ismomol or substantially equimolar of lysine constituting polyεlysine and a sulfonic acid group-containing anionic surfactant is suitable.

The sulfonic acid group-containing anionic surfactant may be used alone or in combination of two or more, but it is preferable to use only one of them because of the uniformity of the properties of the electrostatic complex.

The electrostatic composite of the present invention can be produced extremely easily only by mixing polyεlysine and a sulfonic acid group-containing anionic surfactant in a solvent. Water is suitable as the solvent used here. This is because the raw material polyεlysin and the sulfonic acid group-containing anionic surfactant can be satisfactorily dissolved, and since the electrostatic complex as the target compound is insoluble in water, the purpose after the reaction is This is because it is convenient for isolating and purifying substances. However, depending on the water solubility of the sulfonic acid group-containing anionic surfactant, alcohols such as methanol and ethanol; ethers such as THF; amides such as dimethylformamide and dimethylacetamide may be used to enhance their solubility in the reaction solution. A water-soluble organic solvent such as may be added to the reaction solution. However, considering the separation of the electrostatic complex after the reaction is completed, it is preferable to use only water as the solvent.

Since the electrostatic complex of the present invention is water-insoluble, it can be easily separated from the water solvent, so that the concentration of each component in the reaction solution is not particularly limited. For example, the concentration of polyεlysine in the reaction solution is about 0.1% by mass or more and about 10% by mass or less, and the concentration of the sulfonic acid group-containing anionic surfactant is about 0.1% by mass or more and about 10% by mass or less. be able to. The polyεlysine concentration is more preferably 0.5% by mass or more, more preferably 5% by mass or less, still more preferably 2% by mass or less. The concentration of the sulfonic acid group-containing anionic surfactant is more preferably 0.5% by mass or more, further preferably 1% by mass or more, still more preferably 5% by mass or less, and more preferably 2% by mass or less. More preferred.

Regarding the reaction conditions, the reaction solution may be heated, but the reaction proceeds even at room temperature. Further, in order to sufficiently interact the polyεlysine with the sulfonic acid group-containing anionic surfactant, the reaction time can be 10 minutes or more and 10 hours or less, and 30 minutes or more and 5 hours or less. Is more preferable.

Since the electrostatic composite of the present invention is water-insoluble, it can be easily separated from the water solvent by filtration, centrifugation or the like. In addition, the separated electrostatic complex can be washed with water to remove excess polyεlysine, a sulfonic acid group-containing anionic surfactant, and other by-products. Further, the aqueous solvent can be easily removed by washing with acetone or the like. The separated electrostatic complex is preferably dried by a conventional method such as vacuum drying or freeze drying. The higher the degree of drying of the electrostatic complex, the higher the gelling ability. As for the degree of drying, for example, the water content measured by the Karl Fischer method is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, still more preferably 0.5% by mass or less. The smaller the water content, the better, but the water content can be 0% by mass or more, and 0.01% by mass or more.

In the electrostatic complex of the present invention, at least polyεlysine exhibits biodegradability and affinity for organic solvents. In particular, it has the property of absorbing organic solvents and gelling. The organic solvent refers to a solvent other than water, which is liquid under normal temperature and pressure, and for example, a water-insoluble and highly lipophilic solvent can be used, and a non-polar organic solvent can be used. The organic solvent that can be used in the present invention is not particularly limited, and is, for example, a halogenated aliphatic hydrocarbon solvent such as dichloromethane, chloroform, carbon tetrachloride; methanol, ethanol, isopropanol, 1-butanol, 1-pentanol, 1-hexanol. Alcohol-based solvents such as; ether-based solvents such as diethyl ether and tetrahydrofuran; ketone-based solvents such as acetone and methyl ethyl ketone; aliphatic hydrocarbon solvents such as n-pentane, n-hexane and n-heptane; benzene, toluene, xylene and the like. Aromatic hydrocarbon solvents; Halogenized aromatic hydrocarbon solvents such as chlorobenzene; Ester solvents such as propyl formate, methyl acetate, ethyl acetate, butyl acetate; Amido solvents such as dimethylformamide and dimethylacetamide; Examples thereof include sulfoxide-based solvents; organic acid-based solvents such as formic acid and acetic acid; plant-derived essential oils; and triacylglycerols such as triparmitoylglycerol.

The electrostatic complex of the present invention can be effectively gelled by containing an organic solvent having a maximum weight of 60 times by mass. However, considering the use as an organogel and physical characteristics such as toughness, it is particularly preferable to include an organic solvent having a mass of about 30 times by mass. In addition, the electrostatic complex of the present invention has moisturizing properties but does not show water solubility or excessive water absorption. Further, since it has a clear melting point and the melting point and the pyrolysis starting point are sufficiently separated from each other, heat molding is possible. Therefore, it can be used as a biodegradable plastic material and can replace the conventional petroleum-derived material.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples as well as the present invention, and appropriate modifications are made to the extent that it can meet the purposes of the preceding and the following. Of course, it is possible to carry out, and all of them are included in the technical scope of the present invention.

Example 1: Preparation of poly-ε-lysine ion complex (PELIC) Poly-ε-lysine (transferred from JNC Corporation) was dissolved in water to prepare a 25% poly-ε-lysine aqueous solution. Take 5.0 mL of the aqueous solution, add 813.0 μL of 12N hydrochloric acid so that the amino group of polyεlysine and chloride ion are equimolar, and then add 437.0 μL of the same hydrochloric acid to make 20%. An aqueous solution of cationized polyεlysine was prepared. The concentration of cationized polyεlysine in the aqueous solution is 1.25 g / 6.25 mL. 1.0 mL of the 20% cationized poly ε lysine aqueous solution was separated, and 19.0 mL of distilled water was further added to prepare 20.0 mL of the 1% cationized poly ε lysine aqueous solution. The aqueous solution contains 200.0 mg of cationized polyεlysine.
1 hour after mixing the 50.0 mg / 20.0 mL aqueous solution of SDS and the above cationized polyεlysine aqueous solution at room temperature so that the amino group of the cationized polyεlysine and sodium lauryl sulfate (SDS) are equimolar. It was left still. The reaction mixture is centrifuged at 8,000 rpm at 25 ° C. for 10 minutes, the supernatant is discarded, the precipitate is packed in a 1.5 mL Eppen tube in an amount of 100 to 130 mg each, and dried at room temperature for 24 hours using a vacuum dryer. rice field. Hereinafter, the obtained dried product is referred to as "SDS type PELIC".
The reaction efficiency of the SDS-type PELIC obtained by drying was calculated. Specifically, the post-reaction dry weight actually obtained was divided by the theoretical weight when polyεlysine and its counter partner SDS completely reacted. As a result, the reaction efficiency of the SDS type PELIC was about 95%. Considering the recovery loss after the reaction, it is estimated that the reaction efficiency of the SDS-type PELIC reaches virtually 100%. Therefore, it was suggested that the SDS type PELIC is a fully modified type ion complex.

Example 2: Effect of degree of drying on gelation of PELIC An experiment was conducted on whether or not the gelling ability of SDS-type PELIC was affected by the degree of drying. In Example 1, the SDS type PELIC was produced in the same manner except that the drying time was set to 0 to 24 hours and further to a maximum of 120 hours. 10 mg of each SDS-type PELIC was placed in a 2 mL vial, and 30% by mass of chloroform was added to each SDS-type PELIC. After allowing to stand at room temperature, the vial was turned upside down, and if the mixture did not fall, it was judged to be gelled.
As a result of the experiment, it was confirmed that a complete gel could not be formed until the drying time was 2 hours, and the mixture showed semi-gel-like fluidity. When the drying time was 3 hours or more and less than 12 hours, gelation occurred, but the time required for gelation did not fall below 1 hour. However, when the drying time was 12 hours or more, gelation occurred within 1 hour, and when the drying time was 24 hours, gelation occurred within 10 to 30 minutes. Further, when the drying time was 120 hours, it was the same as 24 hours.
As shown in the above results, the more sufficiently dried to remove water, the more effective it was in drawing out the gelling ability of PELIC, and the sufficient gelling ability was maintained despite the excessive drying of 120 hours. Is considered to have a tough structure that is resistant to drying.

Test Example 1: Maximum swelling amount of SDS-type PELIC From Example 2 above, it was clarified that SDS-type PELIC contained chloroform up to about 30 times by mass of its own weight and gelled, but gel up to about several times. An experiment was conducted to see if it could be converted. In Example 2 above, using an SDS-type PELIC having a drying time of 24 hours or 120 hours, the lower limit of the amount of chloroform added is set to 30 times the mass of the SDS-type PELIC and the upper limit is set to 100 times, and gelation is performed every 10 times. The time and the presence or absence of gel formation were confirmed. As a result, even when 60% by mass of chloroform was added, a gel was formed in 1 hour of the standing time. However, at 70 mass times or more, PELIC dropped when the vial was placed upside down. In this experiment, only similar results were obtained between PELIC with a drying time of 24 hours and PELIC with a drying time of 120 hours.

Test Example 2: Limit number of repetitions of gelation For SDS type PELIC, an experiment on the number of regelation was performed. Chloroform was added 30 times by mass with respect to SDS-type PELIC, and when gelled, the cap of the vial was opened and the mixture was allowed to stand at room temperature. A similar operation was performed on a regular basis each day, prior to which the mass was measured to see if chloroform was completely volatilized.
As a result of the experiment, the gelation time tended to be delayed by repeated gelation, and the gelation formation could not be confirmed at the 9th time. However, as the SDS type PELIC used in this experiment, one that has been gelled once and then left at room temperature for 2 weeks is used. Therefore, it was suggested that the gel could be repeatedly gelled at least 8 times even in a normal environment.

Test Example 3: Chloroform retention time SDS type PELIC 10.0 mg is placed in a collection vial (manufactured by IWAKI) having an outer diameter of 15 × height of 40 × mouth inner diameter of 7.4 (mm), and further 200.0 μL of chloroform (about 300.0 mg) is placed. ) Was added and mixed, and then the mixture was left at room temperature without closing the lid, and the change in mass due to the volatilization of chloroform was recorded over time. The same experiment was performed with chloroform alone as a control group. The results are shown in FIG.
As shown in the results shown in FIG. 1, in the case of chloroform alone, the average is about 2.1 mg / under normal temperature conditions.
The mass decreased at a rate of min and all volatilized after 2 hours. On the other hand, in the case of SDS-type PELIC that gels by containing chloroform up to about 60 times its own weight, the speed is about the same as that of chloroform alone until the amount of chloroform becomes about 15 times under the same conditions. The mass decreased in, but after that, it turned to a gradual decrease rate. It took 12 hours for all chloroform to finally volatilize, demonstrating that the SDS-type PELIC has a remarkable chloroform-retaining ability.

Comparative Example 1: Gelling ability of SDS alone An experiment was conducted to confirm whether the gelling ability of SDS-type PELIC was derived from the ion complex of polyεlysine and SDS. Since the above SDS type PELIC is a completely modified type, 10.0 mg contains 6.9 mg of SDS from its mass ratio. Therefore, 6.9 mg of SDS was weighed into a collection vial (manufactured by IWAKI) having an outer diameter of 15 × height of 40 × inner diameter of 7.4 (mm), and after adding 200.0 μL of chloroform, the lid was closed and the progress was observed. ..
As a result, there was no change even after 24 hours, and observation was made until chloroform volatilized in the closed system, but gelation did not appear from beginning to end. Since polyεlysine is insoluble in chloroform in any proportion, it was clarified that the gelling ability of SDS-type PELIC is a unique ability of SDS-type PELIC.

Test Example 4: Formation of electron transfer reaction field using chlorophyll 4.0 mL of chloroform was added to 1.4 mg of chlorophyll a powder to prepare a 0.035% chlorophyll a solution. 10.0 mg of SDS type PELIC was placed in a vial, 200.0 μL of the chlorophyll a solution was further added, and the mixture was allowed to stand in a dark place. After 30 minutes, even if the vial was turned upside down, the chlorophyll a solution was absorbed and gelled, and it was confirmed that the mixture did not fall.
A photograph of the appearance immediately after gelation is shown in FIG. 2 (a). After the gelation was confirmed, the cells were allowed to stand in a dark place and a bright place, respectively, and 12 hours later, the photographs were taken again. A photograph of the appearance of the gel left in a dark place is shown in FIG. 2 (b), and a photograph of the appearance of the gel left in a bright place is shown in FIG. 2 (c).
As shown in FIG. 2 (b), no change in color was observed even when the gel of the present invention was allowed to stand in a dark place, but as shown in FIG. 2 (c), when the gel of the present invention was allowed to stand in a bright place. Changed from dark green peculiar to chlorophyll to brown.
Chlorophyll is present in the chloroplast membrane and plays an important role in photosynthesis, which efficiently absorbs light energy and converts it into chemical energy, producing carbohydrates and oxygen from carbon dioxide and water. However, since chlorophyll is soluble in an organic solvent such as chloroform but insoluble in water, there is a problem in its application to general biotechnology using water as a solvent. On the other hand, according to the results of this experiment, the color change of chlorophyll was confirmed in the bright place, suggesting that chlorophyll absorbs light and decomposes, that is, the desorption of magnesium occurs. As described above, the organogels according to the present invention can be used as a reaction field for water-insoluble compounds such as chlorophyll and membrane proteins, and thus have the potential to be an epoch-making means for utilizing water-insoluble biofunctional materials.

Claims (10)

An electrostatic complex comprising polyεlysine and an anionic surfactant having a sulfonic acid group. The electrostatic composite according to claim 1, wherein the anionic surfactant is a sulfate ester type anionic surfactant. The electrostatic complex according to claim 1 or 2, wherein the ratio of the anionic surfactant to the α-amino group contained in the polyε lysine is 0.9 times molar to equimolar . The electrostatic complex according to any one of claims 1 to 3, wherein the proportion of L-lysine among the lysines constituting the polyε lysine is 90% or more. Organogels comprising polyεlysine, an electrostatic complex containing an anionic surfactant having a sulfonic acid group, and an organic solvent. The organogels according to claim 5, wherein the organic solvent is chloroform. The organogels according to claim 5, wherein the organic solvent is ethanol and / or isopropanol. The organogels according to any one of claims 5 to 7, wherein the anionic surfactant is a sulfate ester type anionic surfactant. The organogels according to any one of claims 5 to 8, wherein the ratio of the anionic surfactant to the α-amino group contained in the polyε lysine is 0.9 times molar to equimolar. The organogels according to any one of claims 5 to 9, wherein the proportion of L-lysine among the lysines constituting the polyε lysine is 90% or more.

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