U.S. patent application number 13/911533 was filed with the patent office on 2013-10-10 for novel lipid dipeptide and gel.
This patent application is currently assigned to Nissan Chemical Industries, Ltd.. The applicant listed for this patent is Nissan Chemical Industries, Ltd.. Invention is credited to Takehisa IWAMA, Nobuhide MIYACHI, Misao MIYAMOTO.
Application Number | 20130267610 13/911533 |
Document ID | / |
Family ID | 41610260 |
Filed Date | 2013-10-10 |
United States Patent
Application |
20130267610 |
Kind Code |
A1 |
MIYAMOTO; Misao ; et
al. |
October 10, 2013 |
NOVEL LIPID DIPEPTIDE AND GEL
Abstract
There is provided a gelator that is capable of forming a gel by
an extremely small amount of addition in a wide pH range from
acidic to alkaline regions, and a gel having high environmental
compatibility, biocompatibility, and biodegradability. A gelator
comprising: a lipid peptide of Formula (1) wherein R.sup.1 is a
C.sub.9-23 aliphatic group, R.sup.2 is a hydrogen atom or a
C.sub.1-4 alkyl group optionally having a C.sub.1-2 branched chain,
R.sup.3 is a --(CH.sub.2).sub.n--X group, n is a number from 1 to
4, and X is an amino group, a guanidino group, a --CONH.sub.2
group, or a 5-membered ring optionally having 1 to 3 nitrogen
atoms, a 6-membered ring optionally having 1 to 3 nitrogen atoms,
or a fused heterocycle including a 5-membered ring and a 6-membered
ring that optionally has 1 to 3 nitrogen atoms); or a
pharmaceutically usable salt of the lipid peptide.
Inventors: |
MIYAMOTO; Misao; (Tokyo,
JP) ; MIYACHI; Nobuhide; (Tokyo, JP) ; IWAMA;
Takehisa; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nissan Chemical Industries, Ltd. |
Tokyo |
|
JP |
|
|
Assignee: |
Nissan Chemical Industries,
Ltd.
Tokyo
JP
|
Family ID: |
41610260 |
Appl. No.: |
13/911533 |
Filed: |
June 6, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13056517 |
Apr 4, 2011 |
|
|
|
PCT/JP2009/061248 |
Jun 19, 2009 |
|
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13911533 |
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Current U.S.
Class: |
514/770 ;
514/769; 514/773; 548/338.1 |
Current CPC
Class: |
C07K 5/06139 20130101;
C07K 5/06026 20130101; A61K 47/22 20130101; C07K 5/06147 20130101;
A61K 9/7007 20130101; A61K 47/10 20130101; A61K 9/0014 20130101;
A61K 47/183 20130101; C07K 5/06052 20130101; C07K 5/1008 20130101;
A61P 17/00 20180101 |
Class at
Publication: |
514/770 ;
548/338.1; 514/773; 514/769 |
International
Class: |
C07K 5/078 20060101
C07K005/078; A61K 47/22 20060101 A61K047/22 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 1, 2008 |
JP |
2008-200108 |
Claims
1. A lipid peptide of Formula (3): ##STR00014## where R.sup.8 is a
C.sub.9-23 aliphatic group, R.sup.9 is a 3-indole methyl group or
an imidazole methyl group, R.sup.10 is a hydrogen atom or a
C.sub.1-4 alkyl group optionally having a C.sub.1-2 branched chain,
and n is a number from 1 to 4, or a pharmaceutically usable salt of
the lipid peptide.
2. A gel comprising: the lipid peptide or the pharmaceutically
usable salt of the lipid peptide as claimed in claim 1; and a
solvent.
3. The gel according to claim 2, wherein the solvent is water, an
alcohol, an aqueous solution, an alcoholic solution, a hydrophilic
organic solution, a higher alcohol, a fatty acid, higher fatty acid
esters, a glyceride, a hydrophobic organic solution, or a miscible
mixed solvent thereof.
4. The gel according to claim 3, wherein the solvent is water, an
alcohol, an aqueous solution, an alcoholic solution, a hydrophilic
organic solution, a higher alcohol, a hydrophobic organic solution,
or a miscible mixed solvent thereof.
5. The gel according to claim 3, wherein the alcoholic solution is
a mixed solution of at least one alcohol selected from a group
consisting of methanol, ethanol, 2-propanol, and i-butanol and
water.
6. The gel according to claim 3, wherein the hydrophilic organic
solution is a mixed solution of at least one hydrophilic organic
solvent selected from a group consisting of acetone, dioxane,
glycerin, propylene glycol and polyethylene glycol, and water.
7. The gel according to claim 3, wherein the hydrophobic organic
solution is a solution of at least one hydrophobic organic solvent
selected from a group consisting of a liquid paraffin, a mineral
oil, hydrogenated polyisobutene and olive oil.
8. The gel according to claim 3, wherein the aqueous solution is an
aqueous solution dissolving at least one inorganic salt selected
from a group consisting of an inorganic carbonate, an inorganic
sulfate, an inorganic phosphate and an inorganic hydrogen
phosphate, or at least one organic salt selected from a group
consisting of an organic amine hydrochloride and an organic amine
acetate.
9. The gel according to claim 8, wherein the inorganic salt is at
least one inorganic salt selected from a group consisting of
calcium carbonate, sodium carbonate, potassium carbonate, sodium
sulfate, potassium sulfate, magnesium sulfate, potassium phosphate,
sodium phosphate, disodium hydrogen phosphate, and sodium
dihydrogen phosphate, and the organic salt is at least one organic
salt selected from a group consisting of ethylenediamine
hydrochloride, ethylenediaminetetraacetate, and
trishydroxymethylaminomethane hydrochloride.
10. The gel according to any one of claim 2, further comprising an
antiseptic.
11. The gel according to any one of claim 2, wherein the gel is a
sheet-shaped gel.
12. A film obtained by evaporation of a solvent from the
sheet-shaped gel according to claim 11.
13. A fiber formed by self-assembly of the lipid peptide or the
pharmaceutically usable salt of the lipid peptide as claimed in
claim 1.
14. The fiber according to claim 13, further comprising a
surfactant.
15. The fiber according to claim 14, wherein the surfactant is an
anionic surfactant, a nonionic surfactant, or a cationic
surfactant.
16. A gel comprising: the fiber of claim 13; and a solvent.
17. The gel according to claim 16, wherein the fiber adheres to or
includes a low-molecular weight compound.
18. The gel according to claim 16, wherein the solvent is water, an
alcohol, an aqueous solution, an alcoholic solution, a hydrophilic
organic solution, a higher alcohol, a fatty acid, higher fatty acid
esters, a glyceride, a hydrophobic organic solution, or a miscible
mixed solvent thereof.
19. The gel according to claim 18, wherein the solvent is water, an
alcohol, an aqueous solution, an alcoholic solution, a hydrophilic
organic solution, a higher alcohol, a hydrophobic organic solution,
or a miscible mixed solvent thereof.
20. The gel according to claim 18, wherein the alcoholic solution
is a mixed solution of at least one alcohol selected from a group
consisting of methanol, ethanol, 2-propanol, and i-butanol and
water.
21. The gel according to claim 18, wherein the hydrophilic organic
solution is a mixed solution of at least one hydrophilic organic
solvent selected from a group consisting of acetone, dioxane,
glycerin, propylene glycol and polyethylene glycol, and water.
22. The gel according to claim 18, wherein the hydrophobic organic
solution is a solution of at least one hydrophobic organic solvent
selected from a group consisting of a liquid paraffin, a mineral
oil, hydrogenated polyisobutene and olive oil.
23. The gel according to claim 18, wherein the aqueous solution is
an aqueous solution dissolving at least one inorganic salt selected
from a group consisting of an inorganic carbonate, an inorganic
sulfate, an inorganic phosphate and an inorganic hydrogen
phosphate, or at least one organic salt selected from a group
consisting of an organic amine hydrochloride and an organic amine
acetate.
24. The gel according to claim 23, wherein the inorganic salt is at
least one inorganic salt selected from a group consisting of
calcium carbonate, sodium carbonate, potassium carbonate, sodium
sulfate, potassium sulfate, magnesium sulfate, potassium phosphate,
sodium phosphate, disodium hydrogen phosphate, and sodium
dihydrogen phosphate, and the organic salt is at least one organic
salt selected from a group consisting of ethylenediamine
hydrochloride, ethylenediaminetetraacetate, and
trishydroxymethylaminomethane hydrochloride.
25. The gel according to any one of claim 16, further comprising an
antiseptic.
26. The gel according to any one of claim 16, wherein the gel is a
sheet-shaped gel.
27. A film obtained by evaporation of a solvent from the
sheet-shaped gel according to claim 26.
28. A fiber formed by self-assembly of a mixture of the lipid
peptide or the pharmaceutically usable salt of the lipid peptide as
claimed in claim 1, and a lipid peptide of Formula (2):
##STR00015## where R.sup.4 is a C.sub.9-23 aliphatic group, each of
R.sup.5, R.sup.6, and R.sup.7 is a hydrogen atom, a C.sub.1-4 alkyl
chain optionally having a C.sub.1-2 branched chain, or
--(CH.sub.2).sub.n--X, and at least one or more of R.sup.5,
R.sup.6, and R.sup.7 is --(CH.sub.2).sub.n--X, n is a number from 1
to 4, X is an amino group, a guanidino group, a --CONH.sub.2 group,
or a 5-membered ring optionally having 1 to 3 nitrogen atoms, a
6-membered ring optionally having 1 to 3 nitrogen atoms, or a fused
heterocycle including a 5-membered ring and a 6-membered ring that
optionally has 1 to 3 nitrogen atoms, and m is a number from 1 to
4, or a pharmacologically usable salt of the lipid peptide.
29. The fiber according to claim 28, further comprising a
surfactant.
30. The fiber according to claim 29, wherein the surfactant is an
anionic surfactant, a nonionic surfactant, or a cationic
surfactant.
31. A gel comprising: the fiber of claim 28; and a solvent.
32. The gel according to claim 31, wherein the fiber adheres to or
includes a low-molecular weight compound.
33. The gel according to claim 31, wherein the solvent is water, an
alcohol, an aqueous solution, an alcoholic solution, a hydrophilic
organic solution, a higher alcohol, a fatty acid, higher fatty acid
esters, a glyceride, a hydrophobic organic solution, or a miscible
mixed solvent thereof.
34. The gel according to claim 33, wherein the solvent is water, an
alcohol, an aqueous solution, an alcoholic solution, a hydrophilic
organic solution, a higher alcohol, a hydrophobic organic solution,
or a miscible mixed solvent thereof.
35. The gel according to claim 33, wherein the alcoholic solution
is a mixed solution of at least one alcohol selected from a group
consisting of methanol, ethanol, 2-propanol, and i-butanol and
water.
36. The gel according to claim 33, wherein the hydrophilic organic
solution is a mixed solution of at least one hydrophilic organic
solvent selected from a group consisting of acetone, dioxane,
glycerin, propylene glycol and polyethylene glycol, and water.
37. The gel according to claim 33, wherein the hydrophobic organic
solution is a solution of at least one hydrophobic organic solvent
selected from a group consisting of a liquid paraffin, a mineral
oil, hydrogenated polyisobutene and olive oil.
38. The gel according to claim 33, wherein the aqueous solution is
an aqueous solution dissolving at least one inorganic salt selected
from a group consisting of an inorganic carbonate, an inorganic
sulfate, an inorganic phosphate and an inorganic hydrogen
phosphate, or at least one organic salt selected from a group
consisting of an organic amine hydrochloride and an organic amine
acetate.
39. The gel according to claim 38, wherein the inorganic salt is at
least one inorganic salt selected from a group consisting of
calcium carbonate, sodium carbonate, potassium carbonate, sodium
sulfate, potassium sulfate, magnesium sulfate, potassium phosphate,
sodium phosphate, disodium hydrogen phosphate, and sodium
dihydrogen phosphate, and the organic salt is at least one organic
salt selected from a group consisting of ethylenediamine
hydrochloride, ethylenediaminetetraacetate, and
trishydroxymethylaminomethane hydrochloride.
40. The gel according to claim 31, further comprising an
antiseptic.
41. The gel according claim 31, wherein the gel is a sheet-shaped
gel.
42. A film obtained by evaporation of a solvent from the
sheet-shaped gel according to claim 41.
43. A method of preparing a gel comprising the steps: adding a
solvent to the lipid peptide or the pharmaceutically usable salt of
the lipid peptide as claimed in claim 1, and heating a resultant
mixture at a temperature of 75.degree. C. or more to dissolve the
lipid peptide or the pharmaceutically usable salt of the lipid
peptide; and allowing a resulting solution to cool to subject the
solution to gelation.
Description
[0001] This is a Continuation of application Ser. No. 13/056,517
filed Jan. 28, 2011, which is a National Phase of International
Patent Application No. PCT/JP2009/061248 filed Jun. 19, 2009. The
disclosure of the prior applications is hereby incorporated by
reference herein in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a gelator including a lipid
dipeptide, a fiber formed by self-assembly of the gelator, a gel
and a gel sheet composed of the gelator or the fiber and various
solutions, and a novel lipid dipeptide usable for them.
[0003] The lipid peptide of the present invention is particularly
suitably used as a gelator in the production of various gel bases
for cosmetics, gel foods such as agar, pharmaceutical products, and
the like. Furthermore, a gel obtained from the lipid peptide is
suitable for commodity applications such as cosmetics, (soft)
contact lenses, disposable diapers, and air fresheners, dryland
farming applications, analytical chemistry applications such as
chromatography, medical and pharmaceutical applications,
biochemical field applications such as protein carriers, cell
culture related base materials, and bioreactors, and various
functional materials.
BACKGROUND ART
[0004] A hydrogel is useful as a gel having high biocompatibility
because it includes water as a medium, and thus is used in wide
fields including commodities such as disposable diapers, cosmetics,
and air fresheners.
[0005] Examples of a conventional hydrogel include natural polymer
gels such as agarose and synthetic polymer gels that are formed by
cross-linking chains of a polymer such as an acrylamide gel through
chemical covalent bonds.
[0006] Recently, functional gels in which various functions such as
substance holding capacities, external stimulus responsive
performance, and biodegradability in consideration of the
environment are imparted to a hydrogel have been attracting much
attention, and there are attempts for providing various functions
by incorporating functional molecules into the natural or the
synthetic polymer gels using copolymerization reaction.
[0007] In order to impart a new function to a hydrogel, it is
required to study the nanostructure and the surface structure of
the gel in detail. However, the method of incorporating a
functional molecule using the copolymerization reaction has various
problems that the introduction rate of a functional group is
limited, that precise molecular design is difficult, that unreacted
residual substances have safety issues, and that gel preparation is
extremely complicated.
[0008] In order to prepare a safe and stable sheet-shaped gel
(so-called a gel sheet) without unreacted residual crosslinking
agents using such hydrogels, a solution dissolving a natural
polymer is placed in a sheet-shape mold and a gel sheet is formed
by gelation. However, physical cross-linkages between natural
polymers are fragile and in an equilibrium state. Thus, when the
gel sheet is immersed in water, the natural polymer is gradually
fallen out from the gel sheet into water to disintegrate the gel
sheet. In this manner, it has been extremely difficult to prepare a
gel sheet only by a physical gel (Non-patent Document 1).
[0009] In contrast to such conventional "top-down type"
developments of functional materials, "bottom-up type" studies for
producing functional materials, in which atoms or molecules as a
minimum unit of substances are assembled to form an assembly and a
new function is found in a supermolecule as the formed assembly,
have been drawing attention.
[0010] Also in the field of gels, a new gel composed of a
noncovalent gel fiber (so-called "nanofiber self-assembly") has
been developed by self-assembly of low molecular compounds. The
"self-assembly" means that, in a substance (molecule) group in a
random state at first, molecules are spontaneously assembled under
suitable external conditions through intermolecular noncovalent
interactions and the like to grow to a macro functional
assembly.
[0011] The new gel draws attention because macroscopic structures
or functions of the gel can be theoretically controlled by
controlling intermolecular interactions or weak noncovalent bonds
of a molecular assembly depending on molecular design of
monomers.
[0012] However, there is no definite method for controlling the
intermolecular interactions or the noncovalent bonds between
low-molecular weight compounds. Furthermore, in the studies of the
noncovalent gel, the study of self-assembly using hydrogen bonds in
an organic solvent is preceded because the gel is comparatively
easily formed, and self-assembled compounds in an aqueous solution
(that is, a hydrogelator and the like) have been found only
incidentally.
[0013] Previously reported hydrogelators forming noncovalent gels
are generally classified into the following three types.
[1. Hydrogelators Having Amphiphilic Low-Molecular Weight Molecule
as Skeleton]
[0014] This type of hydrogelators is modeled on an artificial lipid
membrane. Examples of the hydrogelator include surfactant gelators
having a quaternary ammonium salt part as the hydrophilic portion
and an alkyl long chain as the hydrophobic portion and
twin-surfactant gelators in which hydrophilic portions of two
surfactant molecules are connected.
[0015] As an example of the hydrogel produced by such gelators,
there has been developed a molecular organizational hydrogel formed
by adding an anionic compound having a molecular weight of 90 or
more to an aqueous solution dispersing a cationic amphiphilic
compound having a branched alkyl group as the hydrophobic portion
(Patent Document 1).
[2. Hydrogelators Having Skeleton in Motif of Biocomponents]
[0016] Examples of the hydrogelator include gelators using assembly
between molecular assemblies by a peptide secondary structure
skeleton (such as an .alpha.-helix structure and a .beta.-sheet
structure).
[0017] For example, there has been developed a gelator having an
.alpha.-helix structure (Non-patent Document 2) and a gelator
having a .beta.-sheet structure (Non-patent Document 3).
[3. Hydrogelators Having Semi-Artificial Low-Molecular Weight
Molecule as Skeleton]
[0018] This type of hydrogelators is composed of a combination of a
biocomponent such as DNA bases, peptide chains, and sugar chains
(hydrophilic portion), an alkyl chain (hydrophobic portion), and
the like, and can be considered as a gelator in which the
characteristics of the above two types of gelators are combined.
Here, the DNA bases, the peptide chains, and the sugar chains have
roles not only for improving hydrophilicity but also for imparting
intermolecular interactions such as a hydrogen bond.
[0019] For example, there has been developed a hydrogelator
composed of a glycoside-amino acid derivative including a sugar
structure moiety having a glycoside structure of N-acetylated
monosaccharides or disaccharides (Patent Document 2) and a fine
hollow fiber composed of a peptide lipid of General Formula
"RCO(NHCH.sub.2CO).sub.mOH" and a transition-metal and having
self-assembling property (Patent Document 3).
[0020] There is also disclosed a formation of .beta.-sheet fiber
network from an amphiphilic peptide having a structure of
<hydrophobic portion-cysteine residue (forming disulfide bonds
at the time of network formation)-glycine residue (imparting
flexibility)-phosphorylated serine residue-cell adhesive
peptide> using the hydrophobic portion as a core (Non-patent
Document 4).
[0021] There has been reported preparation of a glycolipid
supermolecular hydrogel using a chemical library (Non-patent
Document 5).
[0022] Amphiphilic dipeptide compounds composed of a hydrophobic
portion and a dipeptide are also drawing attention as one of the
"bottom-up type" functional materials capable of forming a
self-assembly. For example, it is known that a dipeptide compound
having a specific lipid part of "2-(naphthalen-2-yloxy)acetic acid"
and "glycylglycine, glycylserine, or the like" can form a hydrogel.
However, such compounds can form a gel from only an acidic aqueous
solution or a hydrogel formed from each is acidic (Non-patent
Document 6).
[0023] Furthermore, few of the low-molecular weight hydrogels that
have been thus developed can form a gel not only from an aqueous
solution but also from an organic solvent, and hydrogels capable of
forming a gel from both of the solvents have a limited structure.
Even hydrogels capable of forming a gel from both of the solvents
can form a gel only from a combination of water or an aqueous
solution having a limited pH and a specific organic solvent
(Non-patent Documents 7 to 9). That is, there are no gelators that
can form a gel from an aqueous solution in a wide pH range as well
as have gelation properties with respect to an organic solvent
including solvents practically used for cosmetics and the like.
[0024] In contrast, a lipid peptide compound composed of lauric
acid or myristic acid that is a natural fatty acid and
glycylglycine does not form a hydrogel but forms an organic
nanotube including multilayered vesicles of a hollow having an
inner diameter of about 50 to 90 nm to be precipitated (for
example, Patent Document 3). On the other hand, it has been found
that palmitoyl-Gly-Gly-His that is formed by adding histidine to
the C-terminal of glycylglycine and bonding palmitic acid as a
natural fatty acid to the N-terminal has gelation properties.
Moreover, it has been reported that palmitoyl-Gly-Gly-Gly-His that
is formed by bonding palmitic acid to a tetrapeptide in place of
the tripeptide has high gelation properties at a lowest gelation
concentration of only 0.03 wt % (Non-patent Document 10).
[0025] In this manner, it is supposed that when the hydrophilic
portion has a longer peptide chain, the number of hydrogen bonds
between lipid peptides increases, and thus a stably assembled lipid
peptide can be obtained. However, it is unknown until now whether a
lipid peptide compound is self-assembled to form a gel when the
hydrophilic portion has a shorter peptide chain and thus the number
of hydrogen bonds between lipid peptides decreases.
[0026] Furthermore, even by the palmitoyl-Gly-Gly-Gly-His, it has
been reported until now that a gel can be formed only from a few
mediums such as 1 N hydrochloric acid aqueous solution, neutral and
basic aqueous solutions, and a mixed solution of ethanol and water,
and there are no reports on gelation using various acids or
inorganic salts and on gelation of organic solvents used for
cosmetics and external medicines.
RELATED ART DOCUMENTS
Patent Document
[0027] Patent Document 1: Japanese Patent Application Publication
No. JP-A-2002-085957. [0028] Patent Document 2: Japanese Patent
Application Publication No. JP-A-2003-327949. [0029] Patent
Document 3: Japanese Patent Application Publication No.
JP-A-2004-250797.
Non-Patent Document
[0029] [0030] Non-patent Document 1: Katsuyoshi Nishinari, K. S.
Hossain, Shimon Tanaka, Yoko Nitta, Makoto Takemasa, Fang Yapeng,
Toyoichi Tanaka Memorial Symposium, The Discovery of Volume Phase
Transition of Gel--the Following 30 Years, the abstract paper, Sep.
10-12, 2008, SS-1, p. 39. [0031] Non-patent Document 2: W. A.
Pekata et al., SCIENCE, 281, 389 (1998). [0032] Non-patent Document
3: A. Aggeli et al., Angew. Chem. Int. Ed., 2003, 42. 5603-5606.
[0033] Non-patent Document 4: Jeffry D. Hartgerink, Elia Beniaah,
Samuel I. Stupp, SCIENCE, vol 294, 1684-1688 (2001). [0034]
Non-patent Document 5: Shinji Matsumoto, Itaru Hamachi, Jojin News,
No. 118, 1-16 (2006). [0035] Non-patent Document 6: Z. Yang, B. Xu
et al., J. Mater. Chem., 2007, 17, 850-854. [0036] Non-patent
Document 7: P. K. Kumar et al., Chem. Mater., 2007, 19, 138-140.
[0037] Non-patent Document 8: P. K. Kumar and G. John, Chem.
Commun., 2006, 2218-2220. [0038] Non-patent Document 9: Y.
Matsuzawa, M. Abe et al., Adv. Funct. Mater., 2007, 17, 1507-1514.
[0039] Non-patent Document 10: Daisuke Koda, Tatsuo Maruyama, Saori
Sonokawa, Kazuki Nakajima, Masahiro Goto, The 44th Joint Meeting on
Chemistry in Kyushu, July 7th, 2007, the abstract paper.
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0040] In conventional hydrogels, when a synthetic polymer gel is
formed, or sometimes when a gel is formed from a natural polymer
such as gelatin (collagen), a crosslinking agent having an aldehyde
group is required to be used.
[0041] Furthermore, in order to impart a function to a natural
polymer gel as well as a (synthetic) polymer gel, chemical
modification of the polymer chain or copolymerization reaction is
required for incorporating a functional molecule.
[0042] In this manner, conventional hydrogels have problems that
gel preparation is complicated and that unreacted crosslinking
agents or unreacted substances during copolymerization reaction
remain in the gel.
[0043] Furthermore, among previously developed hydrogelators
forming noncovalent gels, the hydrogelator having the amphiphilic
low-molecular weight molecule as the skeleton (1.) may not form a
gel depending on the pH of a medium. That is, in an alkaline
region, the hydrogelator forms micelles to become an emulsion. In
contrast, in an acidic region, the hydrogelator is fibrously
self-assembled to form a hydrogel. However, in a neutral region
that is considered to be safe for living bodies, there are few
reports on hydrogelation. Furthermore, there is a problem that
quaternary ammonium cations and the like (for example Patent
Document 1) may have safety issues in a biological environment.
[0044] The hydrogelator having a skeleton in the motif of
biocomponents (2.) has a problem of productivity, that is,
unsuitable for mass production, and a problem that the gel forming
ability varies depending on temperature or pH.
[0045] The hydrogelator having a semi-artificial low-molecular
weight molecule as the skeleton (3.) also has problems in
biocompatibility and environmental safety. For example, according
to Patent Document 2, the use of high toxic sodium azide is shown
in a reaction scheme (FIG. 1) for synthesizing a glycoside-amino
acid derivative composing the hydrogelator. According to Patent
Document 3, a transition-metal (ion) is required to be added for
self-assembling the hollow fiber.
[0046] In this manner, in previously reported various noncovalent
hydrogels and hydrogelators for forming the gels, there is a demand
for further improvement of the gel forming ability (gel structure
holding ability) and the safety in a biological environment.
[0047] From the viewpoint of the safety in a biological
environment, there is a potential demand of a hydrogelator capable
of forming a gel by a smaller amount of addition.
[0048] For developing such hydrogelators, an amino acid having
three or four or more of peptide units is required when a lipid
peptide having high gel forming ability is developed using a
combination of a natural fatty acid and the amino acid, and thus
the producing process and the like become complicated. Therefore,
there is a demand to provide a compound having a simpler structure
and capable of being produced in a short process and in an
industrial scale.
[0049] Furthermore, from the viewpoint of wide applications for
medical and agrochemical preparations, cosmetics, ink, paint, and
the like, there is a demand to provide a gelator capable of forming
a gel not only from water and an aqueous medium but also from
various solutions and solutions having a wide pH range as well as a
mixed solution of water and an organic solvent and a hydrophobic
organic solution.
[0050] Furthermore, in the case of preparation of a sheet-shaped
gel, that is, a gel sheet, even when a physical gel is used to
prepare a safe gel sheet without a chemical crosslinking agent, a
stable gel sheet that is not disintegrated even when it is immersed
in water cannot be prepared. There is a demand to provide such
safety and stable gel sheet because the gel sheet has moisturizing
effect on skin and the like and has wide applications for a
moisturizing agent for skin, a wound dressing, a face pack, and a
sustained-release carrier for medical and agrochemical
preparations.
[0051] In view of the above-described circumstances, it is an
object of the present invention to provide a gelator including a
novel lipid peptide, in particular, a lipid peptide having high
gelation properties capable of forming a gel by an extremely small
amount of addition from a mixed solution of an alcohol, an organic
solvent, and the like or a solution dissolving an organic acid, an
inorganic acid, an inorganic salt, or an organic salt, in a wide pH
range from acidic to alkaline regions, specifically even in a
neutral region.
[0052] The present invention also has an object to provide a gel
that is obtained by using the gelator including the lipid peptide,
that keeps a stable gel structure in a wide pH range from acidic to
alkaline regions, and that has high environmental compatibility,
biocompatibility, and biodegradability.
[0053] The present invention has an object to provide a gelator and
a gel capable of forming a safety and stable sheet-shaped gel
(so-called a gel sheet) only by physical cross-linkages without a
crosslinking agent.
[0054] The present invention has a further object to provide a gel
that is formed by adsorption or inclusion of a low-molecular weight
compound to a fiber formed by self-assembling the gelator including
the lipid peptide and that can be used as base materials for
medical and agrochemical preparations capable of
sustained-releasing the low-molecular weight compound.
[0055] The present invention also has an object to provide a novel
lipid peptide capable of providing the gelation properties and the
gel.
Means for Solving the Problem
[0056] The inventors of the present invention have carried out
intensive studies in order to solve the problems, and as a result,
have found the present invention. That is, as a first aspect, a
gelator is characterized by including a lipid peptide of Formula
(1):
##STR00001##
[0057] (where R.sup.1 is a C.sub.9-23 aliphatic group, R.sup.2 is a
hydrogen atom or a C.sub.1-4 alkyl group optionally having a
C.sub.1-2 branched chain, R.sup.3 is a --(CH.sub.2).sub.n--X group,
n is a number from 1 to 4, and X is an amino group, a guanidino
group, a --CONH.sub.2 group, or a 5-membered ring optionally having
1 to 3 nitrogen atoms, a 6-membered ring optionally having 1 to 3
nitrogen atoms, or a fused heterocycle including a 5-membered ring
and a 6-membered ring that optionally has 1 to 3 nitrogen atoms) or
a pharmaceutically usable salt of the lipid peptide.
[0058] As a second aspect, in the gelator according to the first
aspect, R.sup.3 is a --(CH.sub.2).sub.n--X group, n is a number
from 1 to 4, and X is an amino group, a guanidino group, a
--CONH.sub.2 group, or a 5-membered ring optionally having 1 to 2
nitrogen atoms or a fused heterocycle including a 5-membered ring
and a 6-membered ring that optionally has 1 to 2 nitrogen
atoms.
[0059] As a third aspect, in the gelator according to the first
aspect or the second aspect, R.sup.1 is a C.sub.11-21 straight
chain aliphatic group optionally having 0 to 2 unsaturated
bonds.
[0060] As a fourth aspect, in the gelator according to the third
aspect, R.sup.2 is a hydrogen atom or a C.sub.1-3 alkyl group
optionally having a C.sub.1 branched chain.
[0061] As a fifth aspect, in the gelator according to the fourth
aspect, n is a number from 1 to 4 and X is an amino group, a
guanidino group, or a --CONH.sub.2 group, or n is 1 and X is a
pyrrole group, an imidazole group, a pyrazole group, or an
imidazole group.
[0062] As a sixth aspect, in the gelator according to the fifth
aspect, R.sup.2 is a hydrogen atom, a methyl group, an ethyl group,
a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl
group, a sec-butyl group, or a tert-butyl group, and R.sup.3 is an
aminomethyl group, an aminoethyl group, a 3-aminopropyl group, a
4-aminobutyl group, a carbamoylmethyl group, a 2-carbamoylethyl
group, a 3-carbamoylbutyl group, a 2-guanidinoethyl group, a
3-guanidinobutyl group, a pyrrole methyl group, an imidazole methyl
group, a pyrazole methyl group, or a 3-indole methyl group.
[0063] As a seventh aspect, in the gelator according to the sixth
aspect, R.sup.2 is a hydrogen atom, a methyl group, an isopropyl
group, an isobutyl group, or a sec-butyl group, and R.sup.3 is a
4-aminobutyl group, a carbamoylmethyl group, a 2-carbamoylethyl
group, a 3-guanidinobutyl group, an imidazole methyl group, or a
3-indole methyl group.
[0064] As an eighth aspect, a fiber is formed by self-assembly of
the gelator as described in any one of the first aspect to the
seventh aspect.
[0065] As a ninth aspect, a fiber is formed by self-assembly of a
mixture of the gelator as described in any one of the first aspect
to the seventh aspect and a gelator including a lipid peptide of
Formula (2):
##STR00002##
[0066] (where R.sup.4 is a C.sub.9-23 aliphatic group, each of
R.sup.5, R.sup.6, and R.sup.7 is a hydrogen atom, a C.sub.1-4 alkyl
chain optionally having a C.sub.1-2 branched chain, or
--(CH.sub.2).sub.n--X and at least one or more of R.sup.5, R.sup.6,
and R.sup.7 is --(CH.sub.2).sub.n--X, n is a number from 1 to 4, X
is an amino group, a guanidino group, a --CONH.sub.2 group, or a
5-membered ring optionally having 1 to 3 nitrogen atoms, a
6-membered ring optionally having 1 to 3 nitrogen atoms, or a fused
heterocycle including a 5-membered ring and a 6-membered ring that
optionally has 1 to 3 nitrogen atoms, and m is a number from 1 to
4) or a pharmacologically usable salt of the lipid peptide.
[0067] As a tenth aspect, in the fiber according to the eighth
aspect or the ninth aspect, the self-assembly is accelerated by
addition of a surfactant.
[0068] As an eleventh aspect, in the fiber according to the tenth
aspect, the surfactant is an anionic surfactant, a nonionic
surfactant, or a cationic surfactant.
[0069] As a twelfth aspect, a gel includes the gelator as claimed
in any one of the first aspect to the seventh aspect and a
solvent.
[0070] As a thirteenth aspect, a gel includes the fiber as claimed
in any one of the eighth aspect to the eleventh aspect and a
solvent.
[0071] As a fourteenth aspect, in the gel according to the
thirteenth aspect, the fiber adheres to or includes a low-molecular
weight compound.
[0072] As a fifteenth aspect, in the gel according to the twelfth
aspect or the thirteenth aspect, the solvent is water, an alcohol,
an aqueous solution, an alcoholic solution, a hydrophilic organic
solution, a higher alcohol, a fatty acid, higher fatty acid esters,
a glyceride, a hydrophobic organic solution, or a miscible mixed
solvent thereof.
[0073] As a sixteenth aspect, in the gel according to the fifteenth
aspect, the solvent is water, an alcohol, an aqueous solution, an
alcoholic solution, a hydrophilic organic solution, a higher
alcohol, a hydrophobic organic solution, or a miscible mixed
solvent thereof.
[0074] As a seventeenth aspect, in the gel according to the
fifteenth aspect, the alcoholic solution is a mixed solution of at
least one alcohol selected from a group consisting of methanol,
ethanol, 2-propanol, and i-butanol and water.
[0075] As an eighteenth aspect, in the gel according to the
fifteenth aspect, the hydrophilic organic solution is a mixed
solution of at least one hydrophilic organic solvent selected from
a group consisting of acetone, dioxane, glycerin, propylene glycol,
and polyethylene glycol and water.
[0076] As a nineteenth aspect, in the gel according to the
fifteenth aspect, the hydrophobic organic solution is a solution of
at least one hydrophobic organic solvent selected from a group
consisting of a liquid paraffin, a mineral oil, hydrogenated
polyisobutene, and olive oil.
[0077] As a twentieth aspect, in the gel according to the fifteenth
aspect, the aqueous solution is an aqueous solution dissolving at
least one inorganic salt selected from a group consisting of an
inorganic carbonate, an inorganic sulfate, an inorganic phosphate,
and an inorganic hydrogen phosphate or at least one organic salt
selected from a group consisting of an organic amine hydrochloride
and an organic amine acetate.
[0078] As a twenty-first aspect, in the gel according to the
twentieth aspect, the inorganic salt is at least one inorganic salt
selected from a group consisting of calcium carbonate, sodium
carbonate, potassium carbonate, sodium sulfate, potassium sulfate,
magnesium sulfate, potassium phosphate, sodium phosphate, disodium
hydrogen phosphate, and sodium dihydrogen phosphate, and the
organic salt is at least one organic salt selected from a group
consisting of ethylenediamine hydrochloride,
ethylenediaminetetraacetate, and trishydroxymethylaminomethane
hydrochloride.
[0079] As a twenty-second aspect, the gel according to any one of
the twelfth aspect to the twenty-first aspect further includes an
antiseptic.
[0080] As a twenty-third aspect, the gel according to any one of
the twelfth aspect to the twenty-second aspect in which the gel is
a sheet-shaped gel.
[0081] As a twenty-fourth aspect, a film is obtained by evaporation
of a solvent from the sheet-shaped gel according to the
twenty-third aspect.
[0082] As a twenty-fifth aspect, a lipid peptide of Formula
(1b):
##STR00003##
[0083] (where R.sup.1 is a C.sub.12-22 aliphatic group, R.sup.2 is
a hydrogen atom, and R.sup.3 is a 3-indole methyl group or an
imidazole methyl group) and a pharmaceutically usable salt of the
lipid peptide are provided.
[0084] As a twenty-sixth aspect, a lipid peptide of Formula
(1c):
##STR00004##
[0085] (where R.sup.1 is a C.sub.14-22 aliphatic group, R.sup.2 is
a hydrogen atom, a methyl group, an isopropyl group, an isobutyl
group, or a 2-butyl group, and R.sup.3 is a 4-amino-n-butyl group,
a carbamoylethyl group, a carbamoylmethyl group, an imidazole
methyl group, or a 3-indole methyl group) and a pharmaceutically
usable salt of the lipid peptide are provided.
[0086] As a twenty-seventh aspect, in the lipid peptide and the
pharmaceutically usable salt of the lipid peptide according to the
twenty-sixth aspect, R.sup.2 is a methyl group, an isopropyl group,
an isobutyl group, or a 2-butyl group, and R.sup.3 is a
4-amino-n-butyl group, a carbamoylethyl group, or a carbamoylmethyl
group.
[0087] As a twenty-eighth aspect, in the lipid peptide and the
pharmaceutically usable salt of the lipid peptide according to the
twenty-sixth aspect, R.sup.2 is a methyl group, an isopropyl group,
an isobutyl group, or a 2-butyl group, and R.sup.3 is an imidazole
methyl group or a 3-indole methyl group.
[0088] As a twenty-ninth aspect, in the lipid peptide and the
pharmaceutically usable salt of the lipid peptide according to the
twenty-sixth aspect, R.sup.2 is a hydrogen atom, and R.sup.3 is a
4-amino-n-butyl group, a carbamoylethyl group, or a carbamoylmethyl
group.
[0089] As a thirtieth aspect, a gelator is characterized by
including a lipid peptide of Formula (3):
##STR00005##
[0090] (where R.sup.8 is a C.sub.9-23 aliphatic group, R.sup.9 is a
--(CH.sub.2).sub.n--X group, R.sup.10 is a hydrogen atom or a
C.sub.1-4 alkyl group optionally having a C.sub.1-2 branched chain,
n is a number from 1 to 4, and X is an amino group, a guanidino
group, a --CONH.sub.2 group, or a 5-membered ring optionally having
1 to 3 nitrogen atoms, a 6-membered ring optionally having 1 to 3
nitrogen atoms, or a fused heterocycle including a 5-membered ring
and a 6-membered ring that optionally has 1 to 3 nitrogen atoms),
or a pharmaceutically usable salt of the lipid peptide.
[0091] As a thirty-first aspect, a lipid peptide of Formula
(3):
##STR00006##
[0092] (where R.sup.8 is a C.sub.9-23 aliphatic group, R.sup.9 is a
--(CH.sub.2).sub.n--X group, R.sup.10 is a hydrogen atom or a
C.sub.1-4 alkyl group optionally having a C.sub.1-2 branched chain,
n is a number from 1 to 4, and X is an amino group, a guanidino
group, a --CONH.sub.2 group, or a 5-membered ring optionally having
1 to 3 nitrogen atoms, a 6-membered ring optionally having 1 to 3
nitrogen atoms, or a fused heterocycle including a 5-membered ring
and a 6-membered ring that optionally has 1 to 3 nitrogen atoms)
and a pharmaceutically usable salt of the lipid peptide are
provided.
Effect of the Invention
[0093] The gelator of the present invention can form a gel from an
aqueous solution or an alcoholic aqueous solution by gelation
without a crosslinking agent or the like that is required for
conventional gel formation, and thus an unreacted crosslinking
agent does not remain. Furthermore, the lipid peptide of the
present invention is composed of a low-molecular weight compound,
and thus can form a gel without containing unreacted substances of
functional molecules, which are incorporated for providing
functions in conventional gelators.
[0094] Furthermore, the gelator of the present invention can form a
gel in a wide pH range from an acidic region to an alkaline region.
In particular, from the viewpoint of high safety that is required
in carriers for cell culture, medical materials, cosmetic
materials, and the like, the lipid peptide of the present invention
having gel forming ability even in a neutral region is useful as a
gelator for the applications.
[0095] Furthermore, in the gelator of the present invention, the
lipid peptide of the present invention can form a gel not only from
water but also from various solvents such as an alcohol, an aqueous
solution, an alcoholic solution, a hydrophilic organic solution, a
higher alcohol, a fatty acid, higher fatty acid esters, a
glyceride, and a hydrophobic organic solution as well as a miscible
mixed solvent thereof, and thus the gelator is useful as a gelator
for applications such as agrochemical preparations, ink, and paint
along with the above applications.
[0096] The gelator of the present invention has gel forming ability
as a gelator even when two or more of lipid peptides forming the
gelator are mixed in the gelator.
[0097] Furthermore, even when other various peptides capable of
forming a self-assembly, that is, tripeptides or tetrapeptides
having the N-terminal modified with a fatty acid in addition to the
lipid peptide of Formula (1), are mixed, the gelator of the present
invention can form each self-assembly or a mixed self-assembly.
[0098] Moreover, even from an aqueous solution dissolving an
anionic surfactant, a nonionic surfactant, or a cationic
surfactant, the gelator of the present invention can form a
self-assembly mixed with the surfactant.
[0099] The gelator of the present invention can form a gel capable
of sustained-releasing a low-molecular weight compound that is
adsorbed to or included in a fiber formed by self-assembly of the
gelator.
[0100] The gelator of the present invention is a lipid dipeptide
derivative composed of a fatty acid and two amino acids alone. In
view of conventional arts, in order to obtain a stable gelator,
there is a possible method of increasing the number of amino acids
composing the peptide derivative. In contrast, the inventors of the
present invention have found that even when the number of amino
acids is decreased so as to include only two dipeptides, the
gelator surprisingly has the gelation properties, and have
successfully found a gelator that can be synthesized in a shorter
process than that for a conventional hydrogelator and that can be
commercialized.
[0101] Furthermore, the dipeptide provides a good balance between a
hydrophobic moiety and a hydrophilic moiety. Thus, a gel can be
formed not only from pure water but also from an aqueous solution
containing various acids and/or bases, an alcoholic solvent such as
ethanol, and an organic solvent such as glycerin used for
cosmetics.
[0102] Palmitoyl-Gly-Gly-Gly-His as the conventional art limits
usable aqueous mediums. For example, there is a fact that it is
insoluble in 50 mM citrate buffer with pH 5, 50 mM acetate buffer
with pH 5, and the like even when heated. Furthermore, there is
another fact that palmitoyl-Gly-Gly-Gly-His does not form a gel in
an ethanol/water mixed solvent having an ethanol concentration of
80% or more.
[0103] In contrast, the gelator of the present invention
(palmitoyl-Gly-His) can form a gel in a wide variety of mediums
including such mediums, and thus mediums can be selected from a
much wider range.
[0104] The gelator of the present invention does not use
animal-derived materials (such as collagen, gelatin, and matrigel)
that recently have the issue of BSE infection and the like and uses
an artificial low-molecular weight compound (lipid peptide)
composed of a lipid and a peptide alone. Thus, the obtained gel has
no issue caused by such infection and the like. Moreover, the lipid
peptide can be produced only by amidation of a lipid and a peptide
without using a toxic reagent with high reactivity such as sodium
azide, and thus can suitably be used as a highly safe gelator.
[0105] The lipid peptide of the present invention can be used for
cellular damage protection and Langmuir monolayer along with the
above applications.
[0106] The fiber of the present invention is less prone to cause
rejection of living cells and has excellent cell-adhesive
properties when it is incorporated in a living body because the
peptide part (amino acids) is located on the outermost side (that
is, the fiber surface) during self-assembly of the lipid peptide in
water or an aqueous medium such as an alcohol, an aqueous solution,
an alcoholic solution, and a hydrophilic organic solution. On this
account, the fiber can preferably be used for sustained-release
carriers and adsorbents for medical use, scaffolding materials for
regenerative medicine, and the like.
[0107] In addition to the above applications, the fiber is useful
as stabilizers, dispersants, and wetting agent in food industries,
agriculture and forestry, cosmetic fields, and fiber industries, as
nano components doped with a metal or an electrically conductive
substance in electronics and information fields, and as filter
materials and electrically conductive materials.
[0108] The gel of the present invention is preferably used as
biochemical materials and medical materials for cell culture and
the like because it can stably keep a gel structure in a wide pH
range from an acidic region to an alkaline region, especially in a
neutral condition.
[0109] Furthermore, the gel of the present invention is a highly
safe gel in both biological and environmental aspects because it
can be obtained by addition of a smaller amount of the gelator than
conventional agents as described above.
[0110] Moreover, as described above, the gel obtained from a lipid
peptide as a low-molecular weight compound reduces environmental
and biological burdens because it can be readily decomposed by soil
bacteria and the like when it is used in an external environment,
for example, in soil, and because it can be readily decomposed by
metabolic enzymes when it is used in a living body.
[0111] The gel of the present invention can produce a solution
simultaneously dissolving hydrophilic compounds and hydrophobic
compounds because the gelator (lipid peptide) is self-assembled to
form a fiber structure and a hydrophobic compound such as vitamin E
and methylparaben is incorporated into the fiber to be solubilized.
That is, the gel is effectively used for producing cosmetics,
quasi-drugs, pharmaceutical products, agrochemical products, and
the like when a compound to be solubilized is a physiologically
active substance, and is useful for base materials of ink, paint,
and the like when a material to be solubilized is a dye or a
pigment.
[0112] The gel of the present invention is formed by
self-assembling the gelator. Thus, a sheet-shaped gel (so-called a
gel sheet) obtained by gelation from a solution dissolving the
gelator in a sheet-shaped mold becomes a safe and stable gel sheet
that includes no chemical cross-linkages and that is not
disintegrated even when it is immersed in a solution such as water.
That is, such gel sheet has moisturizing effect, can release drugs
or can trap harmful compounds, and thus is useful as moisturizing
agents, face packs, and base materials for external preparations
such as wound dressing.
[0113] Moreover, when a solvent in the gel sheet is evaporated
without freeze-drying, a film including a lipid peptide as the
gelator can be prepared.
BRIEF DESCRIPTION OF THE DRAWINGS
[0114] FIG. 1 is a schematic diagram showing self-assembly of lipid
peptides and the following gelation.
[0115] FIG. 2 is a figure showing fluorescence intensities measured
on two gels and a solution prepared in Example 32.
[0116] FIG. 3 is views showing solubilization of a milky solution
containing vitamin E and a vitamin C derivative prepared in Example
34.
BEST MODES FOR CARRYING OUT THE INVENTION
[0117] The present invention will be described in further detail.
In the present invention, "n" means normal, "i" means iso, "s" or
"sec" means secondary, "t" or "tert" means tertiary, "c" means
cyclo, "o" means ortho, "m" means meta, "p" means para, "Me" means
a methyl group, "Bu" means a butyl group, and "tBu" means a
tertiary butyl group.
[0118] [Gelator]
[0119] The gelator of the present invention includes a lipid
peptide having the structure of (1) below or its pharmaceutically
usable salt. The lipid peptide includes a lipid portion
(alkylcarbonyl group) having a highly lipophilic chain and a
hydrophilic peptide portion (dipeptide).
##STR00007##
[0120] In (1), it is desirable that R' included in the lipid
portion be a C.sub.9-23 aliphatic group and R.sup.1 preferably be a
C.sub.11-21 straight chain aliphatic group or a C.sub.11-21
straight chain aliphatic group having one or two unsaturated
bonds.
[0121] Specific examples of the particularly preferable aliphatic
group of R.sup.1 include a nonyl group, a decyl group (caprylic
group), a undecyl group, a dodecyl group (lauryl group), a tridecyl
group, a tetradecyl group (myristyl group), a pentadecyl group, a
hexadecyl group (palmityl group), a heptadecyl group, an octadecyl
group (stearyl group), a nonadecyl group, an icosyl group, and a
henicosyl group.
[0122] In Formula (1), R.sup.2 included in the peptide portion is a
hydrogen atom or a C.sub.1-4 alkyl group optionally having a
C.sub.1-2 branched chain, and R.sup.3 is a --(CH.sub.2).sub.n--X
group.
[0123] In the --(CH.sub.2).sub.n--X group, n is a number from 1 to
4, and X is an amino group, a guanidino group, a --CONH.sub.2
group, or a 5-membered ring, a 6-membered ring, or a fused
heterocycle including a 5-membered ring and a 6-membered ring
optionally having 1 to 3 nitrogen atoms.
[0124] The C.sub.1-4 alkyl group optionally having a C.sub.1-2
branched chain in R.sup.2 means an alkyl group that has a C.sub.1-4
main chain and may have a C.sub.1-2 branched chain. Specific
examples of the group include a methyl group, an ethyl group, a
n-propyl group, an i-propyl group, a n-butyl group, an i-butyl
group, a sec-butyl group, and a tert-butyl group.
[0125] R.sup.2 is preferably a hydrogen atom or a C.sub.1-3 alkyl
group optionally having a C.sub.1 branched chain and more
preferably a hydrogen atom. The C.sub.1-3 alkyl group optionally
having a C.sub.1 branched chain means an alkyl group that has a
C.sub.1-3 main chain and may have a C.sub.1 branched chain.
Specific examples of the group include a methyl group, an ethyl
group, a n-propyl group, an i-propyl group, an i-butyl group, and a
sec-butyl group. The group is preferably a methyl group, an
i-propyl group, an i-butyl group, or a sec-butyl group.
[0126] In the --(CH.sub.2).sub.n-- group, X is preferably an amino
group, a guanidino group, a --CONH.sub.2 group, a pyrrole group, an
imidazole group, a pyrazole group, or an indole group and more
preferably an imidazole group. Furthermore, in the
--(CH.sub.2).sub.n-- group, n is preferably 1 or 2 and more
preferably 1.
[0127] Thus, the --(CH.sub.2).sub.n-- group is preferably an
aminomethyl group, a 2-aminoethyl group, a 3-aminopropyl group, a
4-aminobutyl group, a carbamoylmethyl group, a 2-carbamoylethyl
group, a 3-carbamoylbutyl group, a 2-guanidinoethyl group, a
3-guanidinobutyl group, a pyrrole methyl group, an imidazole methyl
group, a pyrazole methyl group, or a 3-indole methyl group, more
preferably a 4-aminobutyl group, a carbamoylmethyl group, a
2-carbamoylethyl group, a 3-guanidinobutyl group, an imidazole
methyl group, or a 3-indole methyl group, and even more preferably
an imidazole methyl group.
[0128] Specific examples of the particularly preferable lipid
peptide compound of Formula (1) include compounds composed of a
lipid portion and a dipeptide portion shown below. Here, the
following abbreviations are used for the respective amino acids:
histidine (His); glycine (Gly); valine (Val); isoleucine (Ile);
alanine (Ala); arginine (Arg); asparagine (Asn); glutamine (Gln);
lysine (Lys); and tryptophan (Trp). That is, N-lauroyl-Gly-His,
N-lauroyl-Gly-Trp, N-lauroyl-Gly-Gln, N-lauroyl-Gly-Asn,
N-lauroyl-Gly-Arg, N-lauroyl-Gly-Lys, N-lauroyl-Ala-His,
N-lauroyl-Ala-Trp, N-lauroyl-Ala-Gln, N-lauroyl-Ala-Asn,
N-lauroyl-Ala-Arg, N-lauroyl-Ala-Lys, N-lauroyl-Val-His,
N-lauroyl-Val-Trp, N-lauroyl-Val-Gln, N-lauroyl-Val-Asn,
N-lauroyl-Val-Arg, N-lauroyl-Val-Lys, N-lauroyl-Leu-His,
N-lauroyl-Leu-Trp, N-lauroyl-Leu-Gln, N-lauroyl-Leu-Asn,
N-lauroyl-Leu-Arg, N-lauroyl-Leu-Lys, N-lauroyl-Ile-His,
N-lauroyl-Ile-Trp, N-lauroyl-Ile-Gln, N-lauroyl-Ile-Asn,
N-lauroyl-Ile-Arg, N-lauroyl-Ile-Lys, N-myristoyl-Gly-His,
N-myristoyl-Gly-Trp, N-myristoyl-Gly-Gln, N-myristoyl-Gly-Asn,
N-myristoyl-Gly-Arg, N-myristoyl-Gly-Lys, N-myristoyl-Ala-His,
N-myristoyl-Ala-Trp, N-myristoyl-Ala-Gln, N-myristoyl-Ala-Asn,
N-myristoyl-Ala-Arg, N-myristoyl-Ala-Lys, N-myristoyl-Val-His,
N-myristoyl-Val-Trp, N-myristoyl-Val-Gln, N-myristoyl-Val-Asn,
N-myristoyl-Val-Arg, N-myristoyl-Val-Lys, N-myristoyl-Leu-His,
N-myristoyl-Leu-Trp, N-myristoyl-Leu-Gln, N-myristoyl-Leu-Asn,
N-myristoyl-Leu-Arg, N-myristoyl-Leu-Lys, N-myristoyl-Ile-His,
N-myristoyl-Ile-Trp, N-myristoyl-Ile-Gln, N-myristoyl-Ile-Asn,
N-myristoyl-Ile-Arg, N-myristoyl-Ile-Lys, N-palmitoyl-Gly-His,
N-palmitoyl-Gly-Trp, N-palmitoyl-Gly-Gln, N-palmitoyl-Gly-Asn,
N-palmitoyl-Gly-Arg, N-palmitoyl-Gly-Lys, N-palmitoyl-Ala-His,
N-palmitoyl-Ala-Trp, N-palmitoyl-Ala-Gln, N-palmitoyl-Ala-Asn,
N-palmitoyl-Ala-Arg, N-palmitoyl-Ala-Lys, N-palmitoyl-Val-His,
N-palmitoyl-Val-Trp, N-palmitoyl-Val-Gln, N-palmitoyl-Val-Asn,
N-palmitoyl-Val-Arg, N-palmitoyl-Val-Lys, N-palmitoyl-Leu-His,
N-palmitoyl-Leu-Trp, N-palmitoyl-Leu-Gln, N-palmitoyl-Leu-Asn,
N-palmitoyl-Leu-Arg, N-palmitoyl-Leu-Lys, N-palmitoyl-Ile-His,
N-palmitoyl-Ile-Trp, N-palmitoyl-Ile-Gln, N-palmitoyl-Ile-Asn,
N-palmitoyl-Ile-Arg, N-palmitoyl-Ile-Lys, N-margaroyl-Gly-His,
N-margaroyl-Gly-Trp, N-margaroyl-Gly-Gln, N-margaroyl-Gly-Asn,
N-margaroyl-Gly-Arg, N-margaroyl-Gly-Lys, N-margaroyl-Ala-His,
N-margaroyl-Ala-Trp, N-margaroyl-Ala-Gln, N-margaroyl-Ala-Asn,
N-margaroyl-Ala-Arg, N-margaroyl-Ala-Lys, N-margaroyl-Val-His,
N-margaroyl-Val-Trp, N-margaroyl-Val-Gln, N-margaroyl-Val-Asn,
N-margaroyl-Val-Arg, N-margaroyl-Val-Lys, N-margaroyl-Leu-His,
N-margaroyl-Leu-Trp, N-margaroyl-Leu-Gln, N-margaroyl-Leu-Asn,
N-margaroyl-Leu-Arg, N-margaroyl-Leu-Lys, N-margaroyl-Ile-His,
N-margaroyl-Ile-Trp, N-margaroyl-Ile-Gln, N-margaroyl-Ile-Asn,
N-margaroyl-Ile-Arg, N-margaroyl-Ile-Lys, N-margaroyl-Gly-His,
N-margaroyl-Gly-Trp, N-margaroyl-Gly-Gln, N-margaroyl-Gly-Asn,
N-margaroyl-Gly-Arg, N-margaroyl-Gly-Lys, N-margaroyl-Ala-His,
N-margaroyl-Ala-Trp, N-margaroyl-Ala-Gln, N-margaroyl-Ala-Asn,
N-margaroyl-Ala-Arg, N-margaroyl-Ala-Lys, N-margaroyl-Val-His,
N-margaroyl-Val-Trp, N-margaroyl-Val-Gln, N-margaroyl-Val-Asn,
N-margaroyl-Val-Arg, N-margaroyl-Val-Lys, N-margaroyl-Leu-His,
N-margaroyl-Leu-Trp, N-margaroyl-Leu-Gln, N-margaroyl-Leu-Asn,
N-margaroyl-Leu-Arg, N-margaroyl-Leu-Lys, N-margaroyl-Ile-His,
N-margaroyl-Ile-Trp, N-margaroyl-Ile-Gln, N-margaroyl-Ile-Asn,
N-margaroyl-Ile-Arg, N-margaroyl-Ile-Lys, N-stearoyl-Gly-His,
N-stearoyl-Gly-Trp, N-stearoyl-Gly-Gln, N-stearoyl-Gly-Asn,
N-stearoyl-Gly-Arg, N-stearoyl-Gly-Lys, N-stearoyl-Ala-His,
N-stearoyl-Ala-Trp, N-stearoyl-Ala-Gln, N-stearoyl-Ala-Asn,
N-stearoyl-Ala-Arg, N-stearoyl-Ala-Lys, N-stearoyl-Val-His,
N-stearoyl-Val-Trp, N-stearoyl-Val-Gln, N-stearoyl-Val-Asn,
N-stearoyl-Val-Arg, N-stearoyl-Val-Lys, N-stearoyl-Leu-His,
N-stearoyl-Leu-Trp, N-stearoyl-Leu-Gln, N-stearoyl-Leu-Asn,
N-stearoyl-Leu-Arg, N-stearoyl-Leu-Lys, N-stearoyl-Ile-His,
N-stearoyl-Ile-Trp, N-stearoyl-Ile-Gln, N-stearoyl-Ile-Asn,
N-stearoyl-Ile-Arg, N-stearoyl-Ile-Lys, N-elaidoyl-Gly-His,
N-elaidoyl-Gly-Trp, N-elaidoyl-Gly-Gln, N-elaidoyl-Gly-Asn,
N-elaidoyl-Gly-Arg, N-elaidoyl-Gly-Lys, N-elaidoyl-Ala-His,
N-elaidoyl-Ala-Trp, N-elaidoyl-Ala-Gln, N-elaidoyl-Ala-Asn,
N-elaidoyl-Ala-Arg, N-elaidoyl-Ala-Lys, N-elaidoyl-Val-His,
N-elaidoyl-Val-Trp, N-elaidoyl-Val-Gln, N-elaidoyl-Val-Asn,
N-elaidoyl-Val-Arg, N-elaidoyl-Val-Lys, N-elaidoyl-Leu-His,
N-elaidoyl-Leu-Trp, N-elaidoyl-Leu-Gln, N-elaidoyl-Leu-Asn,
N-elaidoyl-Leu-Arg, N-elaidoyl-Leu-Lys, N-elaidoyl-Ile-His,
N-elaidoyl-Ile-Trp, N-elaidoyl-Ile-Gln, N-elaidoyl-Ile-Asn,
N-elaidoyl-Ile-Arg, N-elaidoyl-Ile-Lys, N-arachidoyl-Gly-His,
N-arachidoyl-Gly-Trp, N-arachidoyl-Gly-Gln, N-arachidoyl-Gly-Asn,
N-arachidoyl-Gly-Arg, N-arachidoyl-Gly-Lys, N-arachidoyl-Ala-His,
N-arachidoyl-Ala-Trp, N-arachidoyl-Ala-Gln, N-arachidoyl-Ala-Asn,
N-arachidoyl-Ala-Arg, N-arachidoyl-Ala-Lys, N-arachidoyl-Val-His,
N-arachidoyl-Val-Trp, N-arachidoyl-Val-Gln, N-arachidoyl-Val-Asn,
N-arachidoyl-Val-Arg, N-arachidoyl-Val-Lys, N-arachidoyl-Leu-His,
N-arachidoyl-Leu-Trp, N-arachidoyl-Leu-Gln, N-arachidoyl-Leu-Asn,
N-arachidoyl-Leu-Arg, N-arachidoyl-Leu-Lys, N-arachidoyl-Ile-His,
N-arachidoyl-Ile-Trp, N-arachidoyl-Ile-Gln, N-arachidoyl-Ile-Asn,
N-arachidoyl-Ile-Arg, N-arachidoyl-Ile-Lys, N-behenoyl-Gly-His,
N-behenoyl-Gly-Trp, N-behenoyl-Gly-Gln, N-behenoyl-Gly-Asn,
N-behenoyl-Gly-Arg, N-behenoyl-Gly-Lys, N-behenoyl-Ala-His,
N-behenoyl-Ala-Trp, N-behenoyl-Ala-Gln, N-behenoyl-Ala-Asn,
N-behenoyl-Ala-Arg, N-behenoyl-Ala-Lys, N-behenoyl-Val-His,
N-behenoyl-Val-Trp, N-behenoyl-Val-Gln, N-behenoyl-Val-Asn,
N-behenoyl-Val-Arg, N-behenoyl-Val-Lys, N-behenoyl-Leu-His,
N-behenoyl-Leu-Trp, N-behenoyl-Leu-Gln, N-behenoyl-Leu-Asn,
N-behenoyl-Leu-Arg, N-behenoyl-Leu-Lys, N-behenoyl-Ile-His,
N-behenoyl-Ile-Trp, N-behenoyl-Ile-Gln, N-behenoyl-Ile-Asn,
N-behenoyl-Ile-Arg, and N-behenoyl-Ile-Lys.
[0129] Among the compounds, more preferable lipid peptide compounds
are N-lauroyl-Gly-His, N-lauroyl-Gly-Trp, N-lauroyl-Gly-Gln,
N-lauroyl-Gly-Asn, N-lauroyl-Gly-Lys, N-lauroyl-Ala-His,
N-lauroyl-Ala-Trp, N-lauroyl-Ala-Gln, N-lauroyl-Ala-Asn,
N-lauroyl-Ala-Lys, N-lauroyl-Val-His, N-lauroyl-Val-Trp,
N-lauroyl-Val-Gln, N-lauroyl-Val-Asn, N-lauroyl-Val-Lys,
N-myristoyl-Gly-His, N-myristoyl-Gly-Trp, N-myristoyl-Gly-Gln,
N-myristoyl-Gly-Asn, N-myristoyl-Gly-Lys, N-myristoyl-Ala-His,
N-myristoyl-Ala-Trp, N-myristoyl-Ala-Gln, N-myristoyl-Ala-Asn,
N-myristoyl-Ala-Lys, N-myristoyl-Val-His, N-myristoyl-Val-Trp,
N-myristoyl-Val-Gln, N-myristoyl-Val-Asn, N-myristoyl-Val-Lys,
N-palmitoyl-Gly-His, N-palmitoyl-Gly-Trp, N-palmitoyl-Gly-Gln,
N-palmitoyl-Gly-Asn, N-palmitoyl-Gly-Lys, N-palmitoyl-Ala-His,
N-palmitoyl-Ala-Trp, N-palmitoyl-Ala-Gln, N-palmitoyl-Ala-Asn,
N-palmitoyl-Ala-Lys, N-palmitoyl-Val-His, N-palmitoyl-Val-Trp,
N-palmitoyl-Val-Gln, N-palmitoyl-Val-Asn, N-palmitoyl-Val-Lys,
N-margaroyl-Gly-His, N-margaroyl-Gly-Trp, N-margaroyl-Gly-Gln,
N-margaroyl-Gly-Asn, N-margaroyl-Gly-Lys, N-margaroyl-Ala-His,
N-margaroyl-Ala-Trp, N-margaroyl-Ala-Gln, N-margaroyl-Ala-Asn,
N-margaroyl-Ala-Lys, N-margaroyl-Val-His, N-margaroyl-Val-Trp,
N-margaroyl-Val-Gln, N-margaroyl-Val-Asn, N-margaroyl-Val-Lys,
N-margaroyl-Gly-His, N-margaroyl-Gly-Trp, N-margaroyl-Gly-Gln,
N-margaroyl-Gly-Asn, N-margaroyl-Gly-Lys, N-margaroyl-Ala-His,
N-margaroyl-Ala-Trp, N-margaroyl-Ala-Gln, N-margaroyl-Ala-Asn,
N-margaroyl-Ala-Lys, N-margaroyl-Val-His, N-margaroyl-Val-Trp,
N-margaroyl-Val-Gln, N-margaroyl-Val-Asn, N-margaroyl-Val-Lys,
N-stearoyl-Gly-His, N-stearoyl-Gly-Trp, N-stearoyl-Gly-Gln,
N-stearoyl-Gly-Asn, N-stearoyl-Gly-Lys, N-stearoyl-Ala-His,
N-stearoyl-Ala-Trp, N-stearoyl-Ala-Gln, N-stearoyl-Ala-Asn,
N-stearoyl-Ala-Lys, N-stearoyl-Val-His, N-stearoyl-Val-Trp,
N-stearoyl-Val-Gln, N-stearoyl-Val-Asn, N-stearoyl-Val-Lys,
N-elaidoyl-Gly-His, N-elaidoyl-Gly-Trp, N-elaidoyl-Gly-Gln,
N-elaidoyl-Gly-Asn, N-elaidoyl-Gly-Lys, N-elaidoyl-Ala-His,
N-elaidoyl-Ala-Trp, N-elaidoyl-Ala-Gln, N-elaidoyl-Ala-Asn,
N-elaidoyl-Ala-Lys, N-elaidoyl-Val-His, N-elaidoyl-Val-Trp,
N-elaidoyl-Val-Gln, N-elaidoyl-Val-Asn, N-elaidoyl-Val-Lys,
N-arachidoyl-Gly-His, N-arachidoyl-Gly-Trp, N-arachidoyl-Gly-Gln,
N-arachidoyl-Gly-Asn, N-arachidoyl-Gly-Lys, N-arachidoyl-Ala-His,
N-arachidoyl-Ala-Trp, N-arachidoyl-Ala-Gln, N-arachidoyl-Ala-Asn,
N-arachidoyl-Ala-Lys, N-arachidoyl-Val-His, N-arachidoyl-Val-Trp,
N-arachidoyl-Val-Gln, N-arachidoyl-Val-Asn, N-arachidoyl-Val-Lys,
N-behenoyl-Gly-His, N-behenoyl-Gly-Trp, N-behenoyl-Gly-Gln,
N-behenoyl-Gly-Asn, N-behenoyl-Gly-Lys, N-behenoyl-Ala-His,
N-behenoyl-Ala-Trp, N-behenoyl-Ala-Gln, N-behenoyl-Ala-Asn,
N-behenoyl-Ala-Lys, N-behenoyl-Val-His, N-behenoyl-Val-Trp,
N-behenoyl-Val-Gln, N-behenoyl-Val-Asn, and N-behenoyl-Val-Lys.
[0130] Most preferable compounds are N-lauroyl-Gly-His,
N-lauroyl-Gly-Gln, N-lauroyl-Gly-Asn, N-lauroyl-Gly-Lys,
N-myristoyl-Gly-His, N-myristoyl-Gly-Gln, N-myristoyl-Gly-Asn,
N-myristoyl-Gly-Lys, N-palmitoyl-Gly-His, N-palmitoyl-Gly-Trp,
N-palmitoyl-Gly-Gln, N-palmitoyl-Gly-Asn, N-palmitoyl-Gly-Lys,
N-palmitoyl-Ala-His, N-palmitoyl-Ala-Trp, N-palmitoyl-Ala-Gln,
N-palmitoyl-Ala-Asn, N-palmitoyl-Ala-Lys, N-palmitoyl-Val-His,
N-palmitoyl-Val-Trp, N-palmitoyl-Val-Gln, N-palmitoyl-Val-Asn,
N-palmitoyl-Val-Lys, N-margaroyl-Gly-His, N-margaroyl-Gly-Gln,
N-margaroyl-Gly-Asn, N-margaroyl-Gly-Lys, N-margaroyl-Gly-His,
N-margaroyl-Gly-Gln, N-margaroyl-Gly-Asn, N-margaroyl-Gly-Lys,
N-stearoyl-Gly-His, N-stearoyl-Gly-Gln, N-stearoyl-Gly-Asn,
N-stearoyl-Gly-Lys, N-elaidoyl-Gly-His, N-elaidoyl-Gly-Gln,
N-elaidoyl-Gly-Asn, N-elaidoyl-Gly-Lys, N-arachidoyl-Gly-His,
N-arachidoyl-Gly-Gln, N-arachidoyl-Gly-Asn, N-arachidoyl-Gly-Lys,
N-behenoyl-Gly-His, N-behenoyl-Gly-Gln, N-behenoyl-Gly-Asn, and
N-behenoyl-Gly-Lys.
[0131] [Fiber and Gel Formed from Gelator]
[0132] When the gelator of the present invention is put into water,
an alcohol, an aqueous solution, an alcoholic solution, a
hydrophilic organic solution, a higher alcohol, a fatty acid,
higher fatty acid esters, a glyceride, a hydrophobic organic
solution, or a miscible mixed solvent of them, a fibrous
self-assembly is formed.
[0133] For example, when the gelator of the present invention is
put into water, an alcohol, an aqueous solution, an alcoholic
solution, or a hydrophilic organic solution, the peptide portion in
Formula (1) forms intermolecular noncovalent bond through hydrogen
bonds, while the lipid portion in Formula (1) is hydrophobically
packed for self-assembly (also called self-organization), and thus
a tubular secondary assembly, that is, a fiber is formed.
[0134] As reference, FIG. 1 shows an exemplified schematic diagram
of self-assembly and gelation of the lipid peptides composing the
gelator of the present invention (however, in the invention, not
all of the lipid peptides form the self-assembly or the gel shown
in FIG. 1).
[0135] The lipid peptide molecules (a) are assembled to place the
lipid portions as the hydrophobic moieties at the center (b) and
self-assembled to form a fiber (c).
[0136] When the gelator of the present invention is put into a
higher alcohol, a fatty acid, a higher fatty acid ester, a
glyceride, or a hydrophobic solution, the peptide portions in
Formula (1) are conversely hydrophilically packed for self-assembly
to form a self-assembly.
[0137] When the fiber is formed in an aqueous medium such as water,
an alcohol, an aqueous solution, an alcoholic solution, or a
hydrophilic organic solution, the fiber forms a three-dimensional
network structure (for example, see FIG. 1(d)), and then
noncovalent bonds are formed between the hydrophilic portion
(peptide portion) on the fiber surface and the aqueous medium so
that the fiber swells. Thus, gelation of the aqueous medium
proceeds to form a hydrogel.
[0138] When the fiber is formed in the hydrophobic medium such as a
higher alcohol, a fatty acid, a higher fatty acid ester, a
glyceride, or a hydrophobic solution, the fiber forms a
three-dimensional network structure, and then the hydrophobic
portion (lipid portion) of the fiber surface and the hydrophobic
medium are assembled through hydrophobic interactions. Thus,
gelation of the hydrophobic medium proceeds to form a gel.
[0139] These gels can be formed in a sheet shape. Furthermore, when
a solvent in the sheet-shaped gel is evaporated, a film can be
prepared.
[0140] The aqueous medium is not specifically limited as far as the
medium does not interfere with self-assembly, fiber formation, and
gelation of the gelator. Specific usable examples of the preferred
aqueous medium include water or an aqueous solution dissolving an
inorganic salt or an organic salt in water (called an aqueous
solution in the present specification), an alcohol or a mixed
solution of water and an alcohol (called an alcoholic solution in
the present specification), and a mixed solution of water and a
hydrophilic organic solvent (called a hydrophilic organic solution
in the present specification).
[0141] The alcohol is preferably a water-soluble alcohol freely
dissolved in water, more preferably a C.sub.1-6 alcohol, even more
preferably methanol, ethanol, 2-propanol, i-butanol, or
1,3-butanediol, and specifically preferably ethanol or
2-propanol.
[0142] The hydrophilic organic solvent means an organic solvent
other than alcohols and an organic solvent capable of being
dissolved in water in any ratio. Usable examples of the hydrophilic
organic solvent include acetone, dioxane, glycerin, polyethylene
glycol, and propylene glycol.
[0143] A plurality of the acids or the salts may be added, and the
acid and the salt may be mixed to be added. The number of acids or
salts added is preferably 1 to 3. Two salts, or one or two acids
and one or two salts are preferably added because the solution
obtains buffering capacity.
[0144] The acid is an inorganic acid or an organic acid. Preferred
examples of the inorganic acid include carbonic acid, sulfuric
acid, and phosphoric acid. The inorganic acid is more preferably
phosphoric acid and even more preferably phosphoric acid. Preferred
examples of the organic acid include acetic acid, citric acid,
succinic acid, and lactic acid. The organic acid is more preferably
lactic acid.
[0145] Preferred examples of the inorganic salt include an
inorganic lactate, an inorganic carbonate, an inorganic sulfate, an
inorganic phosphate, and an inorganic hydrogen phosphate. The
inorganic salt is more preferably potassium lactate, sodium
lactate, calcium carbonate, sodium carbonate, potassium carbonate,
sodium sulfate, potassium sulfate, magnesium sulfate, potassium
phosphate, sodium phosphate, disodium hydrogen phosphate, or sodium
dihydrogen phosphate, and even more preferably potassium lactate,
sodium lactate, calcium carbonate, magnesium sulfate, disodium
hydrogen phosphate, or sodium dihydrogen phosphate.
[0146] Preferred examples of the organic salt include a
hydrochloride of organic amine or an acetate of organic amine. The
organic salt is more preferably ethylenediamine hydrochloride,
ethylenediaminetetraacetate, or trishydroxymethylaminomethane
hydrochloride.
[0147] These inorganic salts and organic salts are commonly
preferably dissolved in water before adding the gelator to be used
as an aqueous solution, but may be added in any step in the process
for forming a gel.
[0148] The hydrophobic medium is not specifically limited as far as
the medium does not interfere with self-assembly, fiber formation,
and gelation of the gelator. Specific usable examples of the
preferred hydrophobic medium include the higher alcohols, the fatty
acids, the higher fatty acid esters, the glycerides, and a solution
of other hydrophobic organic solvents (called a hydrophobic
solution in the present specification).
[0149] Examples of the higher alcohol include stearyl alcohol and
oleyl alcohol, and examples of the fatty acid include stearic acid.
Examples of the higher fatty acid ester include cetyl octanoate,
isopropyl myristate, and isopropyl palmitate.
[0150] Examples of the glyceride include trioctanoin, glyceryl
tri(caprylate/caprate), and glyceryl stearate.
[0151] Examples of the hydrophobic organic solvent include
vegetable oils such as olive oil, coconut oil, castor oil, jojoba
oil, and sunflower seed oil and hydrocarbons such as mineral oils,
hydrogenated isobutene, and liquid paraffin.
[0152] Among the aqueous mediums and the hydrophobic mediums,
specifically preferred mediums are water, 2-propanol, i-butanol,
glycerin, polyethylene glycol, an ethanol aqueous solution, a
2-propanol solution, an i-butanol solution, a propylene glycol
solution, a glycerin solution, a polyethylene glycol solution, a
1,3-butanediol solution, a stearyl alcoholic solution, an oleyl
alcohol solution, and a liquid paraffin solution.
[0153] As the gelator used for forming a fiber or a gel, the
gelator including the lipid peptide of Formula (1) of the present
invention may be used singly or as a mixture of two or more of the
gelators. One or two gelators are preferably used, and more
preferably one gelator is used. When two gelators are used, the
obtained gel is expected to have characteristics different from
those from one agent.
[0154] A gelator other than the gelator including the lipid peptide
of Formula (1) of the present invention, for example, a gelator
including a lipid peptide of Formula (2) below or its
pharmaceutically usable salt may be used as a mixture.
##STR00008##
[0155] In Formula (2), R.sup.4 is a C.sub.9-23 aliphatic group,
each of R.sup.5, R.sup.6, and R.sup.7 is hydrogen, a C.sub.1-4
alkyl chain optionally having a C.sub.1-2 branched chain, or
--(CH.sub.2).sub.n--X and at least one or more of R.sup.5, R.sup.6,
and R.sup.7 is --(CH.sub.2).sub.n--X, n is a number from 1 to 4, X
is an amino group, a guanidino group, a --CONH.sub.2 group, or a
5-membered ring, a 6-membered ring, or a fused heterocycle
including a 5-membered ring and a 6-membered ring optionally having
1 to 3 nitrogen atoms, and m is a number from 1 to 4.
[0156] When the gelator of the present invention is used in
combination with a surfactant at the time of putting into a
hydrophilic medium or a hydrophobic medium, fiber formation and gel
formation can be accelerated. Examples of the surfactant include an
anionic surfactant, a nonionic surfactant, and a cationic
surfactant.
[0157] The present invention is directed a gel that is formed by
adhesion or inclusion of a low-molecular weight compound into the
fiber.
[0158] The gelator (lipid peptide) forming the fiber and the gel of
the present invention has the hydrophilic moiety and the
hydrophobic moiety in the molecule as described above. Thus, for
example, when the fiber simultaneously adheres to or includes a
hydrophobic low-molecular weight compound such as vitamin E and a
hydrophilic low-molecular weight compound such as a vitamin C
derivative, the low-molecular weight compounds can be dissolved in
various solvents.
[0159] Furthermore, a compound having poor water solubility such as
an antiseptic can be solubilized.
[0160] Specific examples of the low-molecular weight compound
capable of adhesion or inclusion into the fiber include a
hydrophobic compound, a hydrophilic compound, a poorly soluble
compound, an enzyme, and pyrene.
[0161] Examples of the hydrophobic compound include vitamin E
(tocopherol), pyrene, azelaic acid derivatives, retinol (vitamin A
alcohol), retinoic acid, hydroxycinnamic acid, caffeine,
hinokitiol, carotenoids, astaxanthin, steroids, indomethacin, and
ketoprofen.
[0162] Examples of the hydrophilic compound include vitamin C
(ascorbic acid), vitamin B2 (riboflavin), kojic acid, glucosamine,
azelaic acid, pyridoxine (vitamin B6), pantothenic acid (vitamin
B5), arbutin, and chitosan.
[0163] Examples of the poorly soluble compound include
phenoxyethanol and methylparaben.
[0164] Examples of the enzyme include cytochrome c.
[0165] When the fiber includes, as the low-molecular weight
compound, for example, ascorbic acid and its derivatives, kojic
acid and its derivatives, glucosamine and its derivatives, azelain
and its derivatives, retinol acid and its derivatives, pyridoxine
and its derivatives, pantothenic acid and its derivatives, arbutin
and its derivatives, tocopherol and its derivatives,
hydroxycinnamic acid and its derivatives, chitosan, chitosan
degradation products, caffeine derivatives, hinokitiol,
carotenoids, and astaxanthin, a gel capable of providing a
whitening effect can be formed.
[0166] When a gel formed from the fiber is in contact with a liquid
or a living body, the gel can gradually release a contained
low-molecular weight compound, that is, can have so-called
sustained-releasing properties. Examples of the low-molecular
weight compound include medical drugs, agrochemicals, and
functional low-molecular weight compounds.
[0167] Detailed mechanisms during formation of the gel of the
present invention are unknown but a charge state of the lipid
peptide molecule is supposed to be involved.
[0168] The lipid peptide of the present invention is a zwitterionic
compound having a carboxy group at the C-terminal and an amino
group derived from a --(CH.sub.2).sub.n--X group that is a side
chain of the peptide portion. Its ionic state is supposed to be in
equilibrium under four states, that is, the state in which only the
carboxy group is negatively charged, the state in which only the
amino group is positively charged, the state in which both of the
groups are charged to be zwitterionic, and the state in which
neither of the groups is charged.
[0169] Considering the acid dissociation constant of an amino acid
residue, it is supposed that, in the lipid peptide molecule, the
terminal amino group derived from the --(CH.sub.2).sub.n--X group
of the peptide portion is positively charged to become a positive
ion in an acidic region, the terminal carboxy group at the
C-terminal of the peptide portion is negatively charged to become a
negative ion in a basic region, and the molecule mainly becomes a
zwitterion in a neutral region.
[0170] When the molecule is ionized, the affinity of the peptide
portion with water increases. Then, the molecules are
self-assembled so that the long chain part as the hydrophobic
moiety will not be in contact with water, and a nanofiber is
formed. At that time, when the zwitterions are predominantly
present, positive ions and negative ions are ionically bonded
between nanofibers to form a cross-linked network structure. When
the network structure is formed, a larger amount of water can be
incorporated, and thus excellent gel forming ability is supposed to
be provided.
[0171] Furthermore, such fiber obtained by the self-assembly of the
low-molecular weight compounds does not fall off from the network
structure formed from self-assembled fibers, unlike the fiber
obtained by the self-assembly of natural polymer compounds.
Moreover, the gelator does not fall off one molecule by one
molecule from the self-assembly, and thus a gel is not
disintegrated.
[0172] When the gelator of the present invention is added
especially into a hydrophobic organic solution, in some cases, into
a hydrophilic solvent and a solvent such as a higher alcohol, a
fatty acid, and a fatty acid ester, it is also supposed that the
peptide portions are assembled at the center, the lipid portions
are assembled on the surface part to form a fiber, and then a three
dimensional network structure is similarly formed to form a
gel.
[0173] The gelator of the present invention is a lipid peptide
composed of a fatty acid having an appropriate number of carbon
atoms and a dipeptide, and thus has an adequate balance between a
size of the hydrophobic moiety and a size of the hydrophilic
moiety. Consequently, it is supposed that the assembling patterns
can be changed both in an aqueous solution and an organic solution,
and thus a gel can be formed in both an aqueous solution and an
organic solvent.
[0174] As described above, the gelator of the present invention can
form a stable gel in a neutral region. Furthermore, the gelator of
the present invention is a low-molecular weight compound, and thus
the gelator and the formed fiber and gel are degradable in an
environment and a living body. Therefore, a gelator and a gel
having high biocompatibility can be obtained.
[0175] On this account, the lipid peptide of the present invention
and the obtained gel therefrom can be used as materials in various
fields such as cell culture carriers, storage materials for
biomolecules such as cells and proteins, base materials for
external preparations, materials for medical use, biochemical
materials, cosmetic materials, food materials, contact lenses,
disposable diapers, artificial actuators, dryland farming
materials. Furthermore, they can widely be used as bioreactor
carriers for enzymes and the like for researches, medical cares,
analyses, and various industries.
[0176] The gel of the present invention is a gel composed of a
low-molecular weight compound (lipid peptide). Thus, depending on a
design of the compound, various functions can be readily added
without polymer chain modification or copolymerization reaction,
for example, a gel that performs sol-gel transformation by external
stimulus response can be formed.
[0177] The present invention is directed to a novel lipid peptide.
The novel lipid peptide is a lipid peptide of Formula (1b):
##STR00009##
(where R.sup.1 is a C.sub.12-22 aliphatic group, R.sup.2 is a
hydrogen atom, and R.sup.3 is a 3-indole methyl group or an
imidazole methyl group) and its pharmaceutically usable salt.
[0178] Alternatively, it is a lipid peptide of Formula (1c):
##STR00010##
(where R.sup.1 is a C.sub.14-22 aliphatic group, R.sup.2 is a
hydrogen atom, a methyl group, an isopropyl group, an isobutyl
group, or a 2-butyl group, and R.sup.3 is a 4-amino-n-butyl group,
a carbamoylethyl group, a carbamoylmethyl group, an imidazole
methyl group, or a 3-indole methyl group) and its pharmaceutically
usable salt.
[0179] In Formula (1c), it is preferable that R.sup.2 be a methyl
group, an isopropyl group, an isobutyl group, or a 2-butyl group,
and R.sup.3 be a 4-amino-n-butyl group, a carbamoylethyl group, or
a carbamoylmethyl group.
[0180] Alternatively, in Formula (1c), it is preferable that
R.sup.2 be a methyl group, an isopropyl group, an isobutyl group,
or a 2-butyl group, and R.sup.3 be an imidazole methyl group or a
3-indole methyl group.
[0181] Furthermore, in Formula (1c), it is preferable that R.sup.2
be a hydrogen atom, and R.sup.3 be a 4-amino-n-butyl group, a
carbamoylethyl group, or a carbamoylmethyl group.
[0182] The present invention is also directed to a gelator
characterized by including a lipid peptide of Formula (3) below or
its pharmaceutically usable salt, and a lipid peptide of Formula
(3) or its pharmaceutically usable salt.
##STR00011##
[0183] In Formula (3), R.sup.8 is a C.sub.9-23 aliphatic group,
R.sup.9 is a --(CH.sub.2).sub.n--X group, R.sup.10 is a hydrogen
atom or a C.sub.1-4 alkyl group optionally having a C.sub.1-2
branched chain, n is a number from 1 to 4, and X is an amino group,
a guanidino group, a --CONH.sub.2 group, or a 5-membered ring, a
6-membered ring, or a fused heterocycle including a 5-membered ring
and a 6-membered ring optionally having 1 to 3 nitrogen atoms.
EXAMPLES
[0184] Hereinafter, the present invention will be described in
further detail with reference to examples, but the present
invention is not limited to these examples.
Abbreviations Used in Examples
[0185] Abbreviations used in the below examples mean the following
compounds. [0186] Gly: glycine [0187] His: histidine [0188] Val:
valine [0189] Ala: alanine [0190] Gln: glutamine [0191] Lys: lysine
[0192] Trp: tryptophan [0193] HBTU:
2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium-hexafluorophosphate
(Watanabe Chemical Industries, Ltd.) [0194] HOBt:
1-hydroxy-benzotriazole (Peptide Institute, Inc.) [0195] DMF:
N,N-dimethylformamide [0196] WSCD:
1-ethyl-3-(3-dimethylaminopropyl)carbodiimide [0197] TFA:
trifluoroacetic acid (Watanabe Chemical Industries, Ltd.) [0198]
TIS: triisopropylsilane (Watanabe Chemical Industries, Ltd.) [0199]
NMP: N-methyl-2-pyrrolidone [0200] DIPEA: N,N-diisopropylethylamine
(Tokyo Chemical Industry Co., Ltd.) [0201] DMSO:
dimethylsulfoxide
[0202] [Lipid Peptide]
[0203] A lipid peptide was synthesized according to the procedure
of Fmoc solid phase peptide synthesis shown below. An amino
acid-Barlos Resin was mainly used as the resin. The synthesis was
performed under a synthesis scale of 0.3 mmol.
##STR00012##
Example 1
Solid Phase Synthesis of N-Palmitoyl-Gly-His.Trifluoroacetate (TFA
Salt)
[0204] To a peptide synthesizer, a reaction container including 163
mg (0.125 mmol) of H-His(Trt)-Trt(2-Cl) resin (0.77 mmol of His per
gram of the resin was added) (Watanabe Chemical Industries, Ltd.)
was installed, and 149 mg (4 eq) of Fmoc-Gly-OH (Watanabe Chemical
Industries, Ltd.) was condensed by Fmoc method to give a
H-Gly-His(Trt)-Trt(2-Cl) resin.
[0205] The obtained wet peptide resin was transferred to a manual
reactor, and 160 mg (5 eq) of palmitic acid (Aldrich), 85 mg (5 eq)
of HOBt, 235 mg (5 eq) of HBTU, 1 ml of DMF, and 2 ml of NMP were
added. The whole was stirred and then 0.22 ml of DIPEA was added.
After 1 hour stirring, a small amount of the resin was sampled to
confirm the reaction completion. The reacted solution was filtered.
Then, the resin was successively washed with NMP and methanol and
then dried under reduced pressure to give 187 mg of
N-palmitoyl-Gly-His(Trt)-Trt(2-Cl) resin.
[0206] A total amount of the dried resin was treated with 1.8 ml of
TFA-TIS-water (95:2.5:2.5), and 37 mg of the obtained crude peptide
was purified with a preparative HPLC system using an ODS column. An
eluted fraction having a desired purity was collected, and
acetonitrile was removed by evaporation. Then, the residue was
further lyophilized to give 32 mg of N-palmitoyl-Gly-His.TFA
salt.
[0207] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.96 (1H,
s), 8.21 (1H, d, J=8.4 Hz), 8.04 (1H, t, J=6.3 Hz), 7.36 (1H, s),
4.57-4.50 (1H, m), 3.65 (2H, d, J=6.3 Hz), 3.14 (1H, m), 2.99 (1H,
m), 2.10 (2H, t, J=7.5 Hz), 1.47 (2H, m), 1.23 (24H, s), 0.85 (3H,
t, J=6.6 Hz).
[0208] MS (EI) m/z: 451.4 (M.sup.++1, bp).
[0209] Conditions for HPLC Purification:
[0210] Column: YMC-Pack ODS-A (250.times.20 mm I.D.)
[0211] Flow rate: 10 mL/min
[0212] Elution: MeCN/0.1% TFA aq.=45/55-(80 minutes, liner
gradient)-65/35
[0213] Detection wavelength: 220 nm
[0214] Temperature: room temperature
Example 2
Liquid Phase Synthesis of N-Palmitoyl-Gly-His.TFA Salt
<Synthesis of N-Palmitoyl-Gly-OtBu>
[0215] Gly-tBu.HCl (8.82 g, 52.6 mmol) and palmitoyl chloride (15.2
ml, 50.1 mmol) were dissolved in 200 ml of chloroform.
Triethylamine (14.6 ml, 105 mmol) was added dropwise to the
solution with stirring while cooling with ice over 10 minutes, and
then the reaction solution was allowed to gradually reach room
temperature and stirred for 15 hours. Water was added, and then the
water was separated. Then, the organic phase was washed with a
saturated saline solution and dried over magnesium sulfate. After
concentration under reduced pressure, the residue was washed with
hexane and filtered to give 17.4 g (94%) of a target compound as a
colorless solid.
[0216] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.09 (1H,
t, J=6.3 Hz), 3.67 (2H, d, J=6.3 Hz), 2.09 (2H, t, J=7.8 Hz), 1.48
(2H, m), 1.39 (9H, s), 1.23 (24H, brs), 0.85 (3H, t, J=6.9 Hz).
[0217] MS (EI) m/z: 314.3 (M.sup.+-Boc-1, bp).
<Synthesis of N-Palmitoyl-Gly>
[0218] To N-palmitoyl-Gly-OtBu (17.4 g, 47.1 mmol), 4M HCl/AcOEt
(118 ml, 0.471 mmol) was added and the whole was stirred at room
temperature for 1 hour. After concentration under reduced pressure,
the residue was washed with hexane to give 11.4 g (77%) of a target
compound as colorless powder.
[0219] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 12.43 (1H,
brs), 8.07 (1H, t, J=5.7 Hz), 3.70 (2H, d, J=5.7 Hz), 2.09 (2H, t,
J=7.8 Hz), 1.47 (2H, m), 1.23 (24H, brs), 0.85 (3H, t, J=6.9
Hz).
<Synthesis of N-Palmitoyl-Gly-His(Trt)-OtBu>
[0220] His(Trt)-OtBu (15.0 g, 33.1 mmol) and HOBt.H.sub.2O (5.13 g,
33.5 mmol) were added to N-palmitoyl-Gly (10.0 g, 31.9 mmol), and
the whole was stirred while cooled with ice. Then, WSCD
hydrochloride (6.42 g, 33.5 mmol) was added, and the whole was
stirred while cooled with ice for 30 minutes and further stirred at
room temperature for 18 hours. Water (500 ml) and ethyl acetate
(400 ml) were added, and then, the aqueous phase was extracted with
ethyl acetate (200 ml). The combined organic phase was successively
washed with a saturated aqueous sodium hydrogen carbonate solution,
a saturated saline solution, 10% citric acid aqueous solution, and
a saturated saline solution, and dried over magnesium sulfate. The
organic phase was concentrated under reduced pressure to give 28.1
g (118%) of a target compound as a pale yellow oily substance.
[0221] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 7.77 (1H,
d, J=7.8 Hz), 7.35-7.29 (10H, m), 7.13-7.07 (6H, m), 6.64-6.58 (2H,
m), 4.67 (1H, m), 3.98 (2H, m), 2.98 (2H, m), 2.22 (2H, m), 1.61
(2H, m), 1.34 (9H, s), 1.25 (24H, brs), 0.87 (3H, t, J=6.6 Hz).
<Synthesis of N-Palmitoyl-Gly-His.TFA Salt>
[0222] A mixture of TFA (206 ml), triisopropylsilane (10.8 ml), and
H.sub.2O (10.8 ml) was added to N-palmitoyl-Gly-His(Trt)-OtBu (23.0
g, 30.8 mmol) while cooling with ice and the whole was stirred at
room temperature for 1 hour. After concentration under reduced
pressure, the residue was washed with diisopropyl ether and then
diethyl ether, and then collected by filtration with a
membrane-filter. The residue was reprecipitated with TFA (35 ml)
and diethyl ether (800 ml), and the precipitate was dried under
reduced pressure to give 16.2 g (93%) of a target compound.
Example 3
Synthesis of N-Palmitoyl-Gly-His.TFA Salt without Protection
##STR00013##
[0223]<Synthesis of N-Palmitoyloxy-Succinimide>
[0224] N-hydroxysuccinimide (69.8 g, 0.598 mol) was added drop by
drop to 1 L of chloroform solution of palmitoyl chloride (165 ml,
0.544 mol) with stirring while cooling with ice, and then
triethylamine (83.1 ml, 0.598 mol) was added dropwise over 30
minutes. Then, the whole was stirred while cooled with ice for 30
minutes, allowed to gradually reach room temperature, and stirred
for 7 hours. The reaction mixture was washed with water (500
ml.times.3), then dried over magnesium sulfate, and concentrated
under reduced pressure to give 260.3 g (quant) of a colorless
solid.
[0225] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 2.80 (4H,
s), 2.65 (2H, t, J=7.2 Hz), 1.61 (2H, quintet, J=7.2 Hz), 1.24
(24H, s), 0.85 (3H, t, J=6.3 Hz).
<Synthesis of N-Palmitoyl-Gly>
[0226] A total amount (260.3 g) of N-palmitoyloxy-succinimide
synthesized above was suspended in 750 ml of DMF. To the
suspension, a solution of Gly (56.3 g, 0.750 mol) and triethylamine
(83.2 ml, 0.598 mol) in 250 ml of water was added dropwise with
stirring while cooling with ice. The whole was stirred for 30
minutes while cooled with ice, then allowed to gradually reach room
temperature, and stirred for 15 hours. An aqueous solution with pH
3 that was prepared by dissolving 100 ml of 6N hydrochloric acid in
1 L of water was stirred while cooled with ice. The reaction
solution containing N-palmitoyloxy-succinimide was added dropwise
to the aqueous solution. The precipitated solid was collected by
filtration. The precipitated solid was washed with 2 L of water and
then 1 L of hexane, and recovered to give 114 g (67%) of a target
compound.
[0227] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.10 (1H,
t, J=6 Hz), 3.71 (2H, d, J=6 Hz), 2.10 (2H, t, J=7.2 Hz), 1.48 (2H,
m), 1.23 (24H, s), 0.85 (3H, t, J=6.3 Hz).
<Synthesis of N-Palmitoyloxy-Glycyloxysuccinimide>
[0228] In 620 ml of DMF, 114 g (0.364 mol) of N-palmitoyl-Gly
synthesized above and N-hydroxysuccinimide (44.0 g, 0.382 mol) were
suspended, and the whole was stirred while cooled with ice. WSCD
hydrochloride (73.2 g, 0.382 mol) was added into the suspension.
The whole was stirred while cooled with ice for 30 minutes and
further stirred at room temperature for 20 hours. To the reaction
mixture, 1.5 L of ice water was added. An insoluble was collected
by filtration, washed with 5 L of water, and then washed with 1.5 L
of ether. Then, the obtained solid was dried under reduced pressure
to give 198 g of a colorless solid quantitatively.
[0229] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, 8 ppm): 8.46 (1H, t,
J=5.7 Hz), 4.22 (2H, d, J=5.7 Hz), 2.89 (4H, s), 2.13 (2H, t, J=7.2
Hz), 1.49 (2H, m), 1.23 (24H, s), 0.85 (3H, t, J=6.3 Hz).
<Synthesis of N-Palmitoyl-Gly-His.TFA Salt>
[0230] A total amount of 198 g of
N-palmitoyloxy-glycyloxysuccinimide synthesized above was suspended
in DMF, and a suspension of 113 g (0.728 mol) of L-histidine and
55.6 ml (0.400 mol) of triethylamine in 350 ml of water was added
with stirring while cooling with ice. Then, the whole was stirred
while cooled with ice for 30 minutes, then allowed to reach room
temperature, and further stirred for 17 hours. A precipitated solid
was collected by filtration without treatment to give a solid. The
solid was added into a solution mixed with 120 ml of
trifluoroacetic acid and 1.5 L of ice water. The whole was stirred,
and then an insoluble was collected by filtration. The obtained
solid was charged into a jug, washed with 2 L of water three times,
and then dried under reduced pressure. The obtained dried solid was
dissolved in 400 ml of trifluoroacetic acid, and a small amount of
insoluble was filtered off with a membrane-filter. The filtrate was
concentrated under reduced pressure to about half the volume. Then,
a solid was washed with diethyl ether and dried under reduced
pressure. The solid was washed with water several times, and the
obtained solid was dried under reduced pressure to give 112 g (54%)
of a colorless solid.
Example 4
Synthesis of Free N-Palmitoyl-Gly-His
[0231] To 2.0 g (4.86 mmol) of N-palmitoyloxy-glycyloxysuccinimide
as the synthetic intermediate in Example 3, 175 mL of DMF was
added, and the whole was cooled in an ice bath. Then, 45 mL of
water, 0.74 mL (5.46 mmol, 1.1 eq) of triethylamine, and 1.50 g
(9.72 mmol, 2.0 eq) of H-L-His-OH were added, and the whole was
reacted for 30 minutes. The reaction mixture was left to reach room
temperature, and then reacted at room temperature for 23.5
hours.
[0232] After the completion of the reaction, the reaction solution
(gel) was centrifuged (4.degree. C., 10,000 rpm, for 15 minutes)
and lyophilized (7 hours.times.2). The gel product with the
supernatant liquid removed was dissolved in 350 mL of methanol.
Insolubles were filtered off, and the filtrate was concentrated
under reduced pressure to make a liquid (A).
[0233] Separately, the supernatant liquid (DMF/aqueous layer) after
the centrifugation was cooled in a refrigerator for 15 hours, and
centrifuged (4.degree. C., 10,000 rpm, for 25 minutes). Then, the
supernatant liquid was removed and the residue was lyophilized (7
hours.times.3). Then, the product was dissolved in 250 mL of
methanol, and insolubles were filtered off to make a liquid
(B).
[0234] The liquid (B) was added to the liquid (A), and the mixture
was concentrated under reduced pressure. The residue was washed
with 150 mL of chloroform and 150 mL of water to give 698.3 mg
(32%) of a white solid.
[0235] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.12 (1H,
d, J=7.8 Hz), 8.06 (1H, t, J=5.7 Hz), 7.56 (1H, s), 6.81 (1H, s),
4.38 (1H, q, J=7.8 Hz), 3.69 (2H, dd, J=5.7 Hz and J=10.2 Hz), 2.89
(2H, m), 2.20 (2H, t, J=6.9 Hz), 1.48 (2H, m), 1.23 (24H, s), 0.85
(3H, t, J=7.2 Hz).
[0236] MS (EI) m/z: 451.43 (M.sup.++1, bp).
Example 5
Neutralization of N-Palmitoyl-Gly-His.TFA Salt
[0237] Into a sample bottle, 500 mg of N-palmitoyl-Gly-His
trifluoroacetate was weighed and placed. Into the bottle, 10 ml of
milli-Q water was added, then 17.7 ml of 0.05M sodium hydroxide
aqueous solution was added, and the whole was mixed. The bottle was
placed in a water bath at 90.degree. C. and the contents were
completely dissolved while gently shaking. After allowing to cool,
the mixture was lyophilized. The obtained solid was washed with
water several times, and then dried under reduced pressure to give
399 g of a neutralized product quantitatively.
Example 6
Synthesis of N-Lauroyl-Gly-His.TFA Salt
[0238] In a similar procedure to that in Example 1, that is, the
H-His(Trt)-Trt(2-Cl) resin was installed; Fmoc-Gly-OH was condensed
by the Fmoc method; finally, lauric acid (Aldrich) was reacted; and
the product was treated with TFA-TIS-water to give a target
compound in a yield of 82%.
[0239] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.59 (1H,
s), 8.19 (1H, d, J=7.4 Hz), 8.05 (1H, t, J=5.7 Hz), 7.22 (1H, s),
4.50 (1H, m), 3.65 (2H, d, J=5.7 Hz), 3.02 (2H, m), 2.11 (2H, t,
J=8.1 Hz), 1.47 (2H, m), 1.23 (16H, brs), 0.85 (3H, t, J=6.9
Hz).
[0240] MS (EI) m/z: 395.4 (M.sup.++1, bp), 214.9.
Example 7
Synthesis of N-Behenoyl-Gly-His.TFA Salt
[0241] In a similar procedure to that in Example 1, that is, the
H-His(Trt)-Trt(2-Cl) resin was installed; Fmoc-Gly-OH was condensed
by the Fmoc method; finally, behenic acid (Aldrich) was reacted;
and the product was treated with TFA-TIS-water to give a target
compound in a yield of 82%.
[0242] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.45 (1H,
s), 8.18 (1H, d, J=8.4 Hz), 8.05 (1H, t, J=5.7 Hz), 7.16 (1H, s),
4.48 (1H, m), 3.65 (2H, d, J=5.7 Hz), 3.00 (21 .mu.m), 2.10 (2H, t,
J=7.5 Hz), 1.47 (2H, m), 1.23 (36H, brs), 0.85 (3H, t, J=7.2
Hz).
[0243] MS (EI) m/z: 535.6 (M.sup.++1, bp), 363.3, 270.1.
Example 8
Synthesis of N-Myristoyl-Gly-His.TFA Salt
[0244] In a similar procedure to that in Example 1, that is, the
H-His(Trt)-Trt(2-Cl) resin was installed; Fmoc-Gly-OH was condensed
by the Fmoc method; finally, myristic acid (Aldrich) was reacted;
and the product was treated with TFA-TIS-water to give a target
compound in a yield of 89%.
[0245] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.93 (1H,
s), 8.22 (1H, d, J=8.4 Hz), 8.05 (1H, t, J=5.7 Hz), 7.35 (1H, s),
4.50 (1H, m), 3.65 (2H, d, J=5.7 Hz), 3.06 (2H, m), 2.10 (2H, t,
J=7.5 Hz), 1.46 (2H, m), 1.23 (20H, brs), 0.85 (3H, t, J=6.6
Hz).
[0246] MS (EI) m/z: 423.4 (M.sup.++1, bp).
Example 9
Synthesis of N-Palmitoyl-Gly-Lys.TFA Salt
[0247] In a similar procedure to that in Example 1, but an
H-Lys(Boc) Resin was installed; [0248] Fmoc-Gly-OH was condensed by
the Fmoc method; finally, palmitic acid (Aldrich) was reacted; and
the product was treated with TFA-TIS-water to give a target
compound.
[0249] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.05-7.98
(2H, m), 7.66 (2H, brs), 4.18 (1H, m), 3.70 (2H, m), 2.76 (2H, m),
2.10 (2H, t, J=7.2 Hz), 1.73-1.47 (6H, m), 1.37-1.23 (26H, brs),
0.85 (3H, t, J=6.6 Hz).
[0250] MS (EI) m/z: 423.4 (M.sup.++1, bp).
Example 10
Synthesis of N-palmitoyl-Ala-His.TFA salt
[0251] In a similar procedure to that in Example 1, that is, the
H-His(Trt)-Trt(2-Cl) resin was installed; Fmoc-Ala-OH was condensed
by the Fmoc method; finally, palmitic acid (Aldrich) was reacted;
and the product was treated with TFA-TIS-water to give a target
compound.
[0252] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.49 (1H,
s), 8.20 (1H, d, J=8.1 Hz), 7.97 (1H, d, J=7.2 Hz), 7.20 (1H, s),
4.47 (1H, m), 4.23 (1H, m), 3.07 (2H, m), 2.07 (2H, t, J=6.9 Hz),
1.45 (2H, m), 1.23 (24H, brs), 1.16 (3H, d, J=6.9 Hz), 0.85 (3H, t,
J=6.6 Hz).
[0253] MS (EI) m/z: 442.4 (M.sup.++1, bp), 297.2.
Example 11
Synthesis of N-Palmitoyl-Val-His.TFA Salt
[0254] In a similar procedure to that in Example 1, that is, the
H-His(Trt)-Trt(2-Cl) resin was installed; Fmoc-Val-OH was condensed
by the Fmoc method; finally, palmitic acid (Aldrich) was reacted;
and the product was treated with TFA-TIS-water to give a target
compound.
[0255] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.53 (1H,
s), 8.31 (1H, d, J=7.5 Hz), 7.82 (1H, d, J=8.7 Hz), 7.20 (1H, s),
4.49 (1H, m), 4.09 (1H, t, J=7.5 Hz), 3.00 (2H, m), 2.22-1.89 (3H,
m), 1.47 (2H, m), 1.23 (24H, brs), 0.83 (9H, m).
[0256] MS (EI) m/z: 493.4 (M.sup.++1, bp).
Example 12
Synthesis of N-palmitoyl-Gly-Trp.TFA salt
[0257] In a similar procedure to that in Example 1, but a
Trp(Boc)Alko resin (Watanabe Chemical Industries, Ltd.) was
installed; Fmoc-Gly-OH was condensed by the Fmoc method; finally,
palmitic acid (Aldrich) was reacted; and the product was treated
with TFA-TIS-water to give a target compound.
[0258] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 10.83 (1H,
s), 7.99-7.91 (2H, m), 7.50 (1H, d, J=7.8 Hz), 7.31 (1H, d, J=8.4
Hz), 7.21-6.94 (3H, m), 4.47 (1H, m), 3.67 (2H, m), 3.17 (1H, m),
3.02 (1H, m), 2.07 (2H, t, J=7.2 Hz), 1.45 (23H, m), 1.23 (24H,
brs), 0.85 (3H, t, J=6.6 Hz).
[0259] MS (EI) m/z: 500.4 (M.sup.++1, bp), 205.1.
Example 13
Synthesis of N-Palmitoyl-Gly-Gln.TFA Salt
[0260] In a similar procedure to that in Example 1, but a
Gln(Trt)-Alko (Watanabe Chemical Industries, Ltd.) was installed;
Fmoc-Gly-OH was condensed by the Fmoc method; finally, palmitic
acid (Aldrich) was reacted; and the product was treated with
TFA-TIS-water to give a target compound.
[0261] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.07 (1H,
d, J=7.5 Hz), 7.95 (1H, m), 4.16 (1H, m), 3.70 (2H, m), 2.10-2.08
(4H, m), 1.92 (1H, m), 1.75 (1H, m), 1.47 (2H, m), 1.23 (24H, brs),
0.85 (3H, t, J=6.6 Hz).
[0262] MS (EI) m/z: 442.3 (M.sup.++1, bp), 130.1.
Example 14
Synthesis of N-Palmitoyl-His-Gly.TFA Salt
[0263] In a similar procedure to that in Example 1, but a glycine
Alko Resin was installed; [0264] Fmoc-His-OH was condensed by the
Fmoc method; finally, palmitic acid (Aldrich) was reacted; and the
product was treated with TFA-TIS-water to give a target
compound.
[0265] .sup.1H-NMR (300 MHz, DMSO-d.sub.6, .delta. ppm): 8.70 (1H,
s, C-2 His), 8.22 (1H, t, J=6 Hz, NH Gly), 8.07 (1H, d, J=8.7 Hz,
NH His), 7.22 (1H, s, C-5 His), 4.62 (1H, m, .alpha.-CH His),
3.84-3.67 (2H, m, .alpha.-CH.sub.2 Gly), 3.07 (1H, m,
.beta.-CH.sub.2a, His), 2.84 (11 .mu.m, .beta.-CH.sub.2b, His),
2.07 (2H, t, J=7.8 Hz, CH.sub.2 Pal), 1.40 (2H, m, CH.sub.2 Pal),
1.23 (24H, brs, CH.sub.2 Pal), 0.85 (311, t, J=6.9 Hz, CH.sub.3
Pal).
[0266] MS (EI) m/z: 451.4 (M.sup.++1, bp).
Example 15
Evaluation of Gelation of Lipid Peptides with Pure Water
[0267] Each of the lipid peptides synthesized in Examples 1, 6, 7,
8, and 10 was placed in a sample tube. Pure water (without metals
and ions) was added so that a solution would have a lipid peptide
concentration of 0.25 or 0.5% (w/v) (w means mass (g), and v means
volume (mL)). The mixture was heated at 90.degree. C. or more to
dissolve the lipid peptide, and then allowed to cool.
[0268] After allowing to cool, a state where the solution had no
flowability and did not run off even when the sample tube was
placed in reverse was determined as "gelation (O)". The results are
shown in Table 1.
TABLE-US-00001 TABLE 1 Evaluation of Gelation of Lipid Peptide with
Pure Water 0.25% 0.50% (w/v) (w/v) Gelation Gelation Example 1
N-palmitoyl-Gly-His.cndot.TFA salt .largecircle. .largecircle.
Example 6 N-lauroyl-Gly-His.cndot.TFA salt .largecircle.
.largecircle. Example 7 N-behenoyl-Gly-His.cndot.TFA salt
.largecircle. .largecircle. Example 8 N-myristoyl-Gly-His.cndot.TFA
salt .largecircle. .largecircle. Example 10
N-palmitoyl-Ala-His.cndot.TFA salt .largecircle. .largecircle.
Example 16
Evaluation of Gelation of Lipid Peptides with Buffer
[0269] Each of the lipid peptides synthesized in Examples 3 to 10
and Example 14 was placed in a sample tube. Each of three phosphate
buffers (PBS) (pH=2.6, 7.4, or 10) was added so that a solution
would have a lipid peptide concentration of 0.25 or 0.5% (w/v)
(conditions A to F). Then, the mixture was heated at 90.degree. C.
or more to dissolve the lipid peptide, and then allowed to
cool.
[0270] After allowing to cool, a state where the solution had no
flowability and did not run off even when the sample tube was
placed in reverse was determined as "gelation". The results are
shown in Table 2. In Table, a sample that formed a gel is shown as
"O", a sample that did not form a gel is shown as "X", and a sample
without evaluation is shown as "-".
TABLE-US-00002 TABLE 2 Evaluation of Gelation of Lipid Peptide with
Phosphate Buffer A B C D E F pH = 2.6 pH-7.4 pH = 10 0.5% 0.25%
0.5% 0.25% 0.5% 0.25% (w/v) (w/v) (w/v) (w/v) (w/v) (w/v) Gelation
Gelation Gelation Gelation Gelation Gelation Example 1
N-palmitoyl-Gly-His.cndot.TFA .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. -- salt Example 6
N-lauroyl-Gly-His.cndot.TFA .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. salt
Example 7 N-behenoyl-Gly-His.cndot.TFA .largecircle. --
.largecircle. .largecircle. .largecircle. -- salt Example 8
N-myristoyl-Gly-His.cndot.TFA .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. -- salt Example
N-palmitoyl-Ala-His.cndot.TFA .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. -- 10 salt Example
N-palmitoyl-Val-His.cndot.TFA -- -- .largecircle. .largecircle.
.largecircle. -- 11 salt Example N-palmitoyl-His-Gly.cndot.TFA --
-- .largecircle. .largecircle. .largecircle. -- 14 salt
[0271] As shown in Table 2, in an acidic region (pH=2.6), at a
concentration of 0.5%, N-palmitoyl-Gly-His.TFA salt,
N-lauroyl-Gly-His.TFA salt, N-behenoyl-Gly-His.TFA salt,
N-myristoyl-Gly-His.TFA salt, and N-palmitoyl-Ala-His.TFA salt
formed gels. At a concentration of 0.25%, N-palmitoyl-Gly-His.TFA
salt, N-lauroyl-Gly-His.TFA salt, N-myristoyl-Gly-His.TFA salt, and
N-palmitoyl-Ala-His.TFA salt formed gels.
[0272] In a neutral region (pH=7.4), all of the lipid peptides used
in Example 16 formed gels at each of concentrations of 0.25 and
0.5%.
[0273] In contrast, in a basic region (pH=10), all of the lipid
peptides used in Example 16 formed gels at a concentration of 0.5%,
but at a concentration of 0.25%, only N-lauroyl-Gly-His.TFA salt
formed a gel.
Example 17
Evaluation of Gelation of N-Palmitoyl-Gly-His.TFA Salt with Various
Solutions
[0274] Each N-palmitoyl-Gly-His trifluoroacetate synthesized in
Examples 1 to 3 was placed in a screw tube (Maruemu No. 1,
manufactured by Maruemu Corp.). Each of various solutions shown in
Table 3 was added so as to have an N-palmitoyl-Gly-His.TFA salt
(also called Pal-GH (TFA)) concentration of 0.5 or 1% (w/v). The
mixture was heated at 100.degree. C. with a constant temperature
heat block (manufactured by Nippon Genetics Co., Ltd.), and then
allowed at room temperature.
[0275] A state where the solution had no flowability and did not
run off even when the screw tube was placed in reverse was
determined as "gelation", and the gel state was observed. The
obtained results are shown in Table 3.
[0276] Each N-palmitoyl-Gly-His trifluoroacetate synthesized in
Examples 1 to 3 is shown without distinction in Table 3 because
each showed similar gelation properties.
TABLE-US-00003 TABLE 3 Evaluation of Gelation of
N-Palmitoyl-Gly-His (TFA) with Various Solutions Pal-GH (TFA)
concentration Solvent % (w/v) Gel state 50% liquid paraffin aqueous
solution 0.5 White gel 50% propylene glycol aqueous solution 0.5
White gel 50% 1,3-butanediol aqueous solution 0.5 White gel 50%
polyethylene glycol 400 aqueous 0.5 White gel solution Polyethylene
glycol 400 1.0 Transparent gel 50% glycerin aqueous solution 0.5
White gel 70% glycerin aqueous solution 0.5 Transparent gel
Glycerin 1.0 Transparent gel
Example 18
Evaluation of Gelation of Phosphate Buffer Using
N-Palmitoyl-Gly-His.TFA Salt and N-Palmitoyl-Gly-Gly-Gly-His.TFA
Salt
[0277] N-palmitoyl-Gly-Gly-Gly-His.TFA salt used in Example 18 and
Example 19 described later were synthesized as below.
[0278] About 390 mg of histidine Barlos Resin (Watanabe Chemical
Industries, Ltd.) was charged into a PD-10 column. The column was
washed with 5 ml of dichloromethane (DCM) three times and further
washed with 5 ml of dimethylformamide (DMF) three times. Next,
about 270 mg of Fmoc-Gly-OH (Watanabe Chemical Industries, Ltd.)
and 2.1 ml of a condensing agent solution 1 (dissolving 3.05 g of
HBTU and 1.25 g of HOBt in 16 ml of DMF) were charged, and 2.1 ml
of a condensing agent solution 2 (dissolving 2.75 ml of DIPEA in
14.25 ml of DMF) was further charged.
[0279] The contents were stirred for 30 minutes with a vibrator,
and then washed with 5 ml of DMF five times, subsequently with 5 ml
of DCM three times, and then with 5 ml of DMF three times.
[0280] Next, 5 ml of 20% piperidine/DMF solution was charged, and
the whole was stirred for 1 minutes. The solution was removed, and
then 5 ml of 20% piperidine/DMF solution was charged again. The
whole was stirred for 45 minutes, and washed with 5 ml of DMF five
times.
[0281] Furthermore, 270 mg of Fmoc-Gly (Watanabe Chemical
Industries, Ltd.), 2.1 ml of the condensing agent 1, and 2.1 ml of
the condensing agent 2 were charged. The whole was stirred for 20
minutes with a vibrator, and then washed with 5 ml of DMF five
times, with 5 ml of DCM three times, and then with 5 ml of DMF
three times. Then, 5 ml of 20% piperidine/DMF solution was charged,
and the whole was stirred for 1 minutes. Then, the solution was
removed, and 5 ml of 20% piperidine/DMF solution was charged again.
The whole was stirred for 45 minutes, and washed with 5 ml of DMF
five times.
[0282] About 230 mg of palmitic acid (Tokyo Chemical Industry Co.,
Ltd.) was charged into the column, 2.1 ml of the condensing agent 1
and 2.1 ml of the condensing agent 2 were charged, and the whole
was stirred for 90 minutes with a vibrator. After the reaction, the
mixture was washed with 5 ml of DMF five times, subsequently with 5
ml of DCM five times, and further with 5 ml of methanol five times,
and then the resin was dried overnight under vacuum.
[0283] After drying, 3.8 ml of trifluoroacetic acid and 0.1 ml of
triisopropylsilane were charged into the column and the whole was
stirred for 1 hour.
[0284] To the recovered mixed solution, water was added to form a
precipitate, and the product was filtered by suction under vacuum.
After freeze-drying, the product was washed with 4 ml of
acetonitrile three times to give a target compound.
[0285] FT-MS.sup.+ m/z calc. for C.sub.26H.sub.46N.sub.5O.sub.5
[M+H].sup.+ 507.34207. found 507.92.
[0286] N-palmitoyl-Gly-His.TFA salt (10.4 mg) containing 5% by mass
of N-palmitoyl-Gly-Gly-His.TFA salt was placed into a screw tube
(Maruemu Corp., No. 3), and a phosphate buffer (phosphate buffer
powder manufactured by Wako Pure Chemical Industries, Ltd., 1/15
mol/L, pH=7.4, composition: Na.sub.2HPO.sub.4 7.6 g,
KH.sub.2PO.sub.4 1.8 g/L) was added so as to have a concentration
of 0.5% (w/v). The whole was heated with a dry bath incubator
(manufactured by First Gene) (105.degree. C., for 10 minutes).
After allowing to cool, a state where the solution had no
flowability and did not run off even when the sample tube was
placed in reverse was ascertained and determined as gelation.
[0287] N-palmitoyl-Gly-His.TFA salt containing 5%
N-palmitoyl-Gly-Gly-His.TFA salt was determined to form a gel by
heat at a concentration of 0.5% (w/v) in a phosphate buffer
medium.
Example 19
Evaluation of Gelation of Ultrapure Water Using
N-Palmitoyl-Gly-His.TFA Salt and N-Palmitoyl-Gly-Gly-Gly-His.TFA
Salt
[0288] N-palmitoyl-Gly-His.TFA salt (10.4 mg) containing 5%
N-palmitoyl-Gly-Gly-His.TFA salt was placed into a screw tube
(Maruemu Corp., No. 3), and ultrapure water (manufactured by Kurita
Water Industries Ltd.) was added so as to have a concentration of
1% (w/v). The whole was heated with a dry bath incubator
(manufactured by First Gene) (105.degree. C., for 10 minutes).
After allowing to cool, a state where the solution had no
flowability and did not run off even when the sample tube was
placed in reverse was ascertained and determined as gelation.
[0289] N-palmitoyl-Gly-His.TFA salt containing 5%
N-palmitoyl-Gly-Gly-His.TFA salt was determined to form a gel by
heat at a concentration of 1% (w/v) in ultrapure water as a
medium.
Example 20
Preparation of Gel and Gel Sheet Using N-Palmitoyl-Gly-His
Trifluoroacetate in Water as Medium
[0290] Into a screw tube (Maruemu No. 3, manufactured by Maruemu
Corp.), 3 mg of N-palmitoyl-Gly-His (TFA) prepared in Example 1 was
placed, and 0.6 ml of Japanese Pharmacopoeia purified water (Kyoei
Pharmaceutical Industries, Ltd.) was added into the screw tube so
as to have a concentration of 0.5% (w/v). The whole was heated at
105.degree. C. for 5 minutes, and then allowed to stand at room
temperature to prepare a gel of 0.5% N-palmitoyl-Gly-His (TFA).
[0291] To the gel, 2 ml of Japanese Pharmacopoeia purified water
(Kyoei Pharmaceutical Industries, Ltd.) was further added and sheet
formation was observed from a wide view for 72 hours. The
N-palmitoyl-Gly-His (TFA) gel prepared in a water medium was not
dissolved during water immersion and the formation of a
sheet-shaped gel was observed.
Example 21
Preparation of Gel and Gel Sheet Using N-Palmitoyl-Gly-His
Trifluoroacetate in Glycerin Solution as Medium
[0292] Into a screw tube (Maruemu No. 3, manufactured by Maruemu
Corp.), 9.1 mg of N-palmitoyl-Gly-His.TFA salt prepared in Example
1 was placed, and 0.91 ml of Japanese Pharmacopoeia purified water
(Kyoei Pharmaceutical Industries, Ltd.) and 0.91 ml of glycerin
(Junsei Chemical Co., Ltd.) were added into the screw tube so as to
have a concentration of 0.5% (w/v). The whole was heated at
105.degree. C. for 5 minutes, and then allowed to stand at room
temperature to prepare a gel of 0.5% N-palmitoyl-Gly-His.TFA salt
in a glycerin solution.
[0293] Into the gel, 2 ml of Japanese Pharmacopoeia purified water
(Kyoei Pharmaceutical Industries, Ltd.) was further added and sheet
formation was observed from a wide view for 72 hours. The gel of
N-palmitoyl-Gly-His.TFA salt prepared in the glycerin solution as a
medium was not dissolved during water immersion and the formation
of a sheet-shaped gel was observed.
Example 22
Preparation of Gel and Gel Sheet Using N-Palmitoyl-Gly-His
Trifluoroacetate in Glycerin as Medium
[0294] Into a screw tube (Maruemu No. 3, manufactured by Maruemu
Corp.), 4.6 mg of N-palmitoyl-Gly-His.TFA salt prepared in Example
1 was placed, and 0.46 ml of glycerin was added into the screw tube
so as to have a concentration of 1% (w/v). The whole was heated at
105.degree. C. for 5 minutes, and then allowed to stand at room
temperature to prepare a gel of 1% N-palmitoyl-Gly-His.TFA salt in
glycerin.
[0295] Into the gel, 2 ml of Japanese Pharmacopoeia purified water
(Kyoei Pharmaceutical Industries, Ltd.) was further added and sheet
formation was observed from a wide view for 72 hours. The gel of
N-palmitoyl-Gly-His.TFA salt prepared in glycerin as a medium was
not dissolved during water immersion and the formation of a
sheet-shaped gel was observed.
Example 23
Evaluation of Gelation of Free N-Palmitoyl-Gly-His in Water and at
Various pHs
[0296] Free N-palmitoyl-Gly-His prepared in Example 4 was placed
into a screw tube (Maruemu No. 1, manufactured by Maruemu Corp.).
Each of the various solutions shown in Table 4 was added into the
screw tube so as to have a free N-palmitoyl-Gly-His (also called
Pal-GH (free)) concentration of 0.1%, 0.2%, 0.5%, 1%, or 2% (w/v).
The mixture was heated at 100.degree. C. with a constant
temperature heat block (manufactured by Nippon Genetics Co., Ltd.),
and then allowed to stand at room temperature.
[0297] After allowing to cool, a state where the solution had no
flowability and did not run off even when the screw tube was placed
in reverse was determined as "gelation". The results are shown in
Table 4. In Table, a sample that formed a gel is shown as "O", a
sample that formed a sol is shown as "X", and a sample without
evaluation is shown as "-".
TABLE-US-00004 TABLE 4 Evaluation of Gelation of Free
N-Palmitoyl-Gly-His in Various pH Solutions Pal-GH Phosphoric
(free) acid concen- aqueous tration solution Phosphate buffer
solution % (w/v) Water pH 2 pH 3 pH 5 pH 6 pH 7.5 pH 9 pH 10 0.1 X
.largecircle. .largecircle. -- -- -- -- -- 0.2 X .largecircle.
.largecircle. .largecircle. .largecircle. -- -- -- 0.5 X
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. X X 1.0 .largecircle. -- -- .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. 2.0
.largecircle. -- -- -- -- -- .largecircle. .largecircle.
Example 24
Evaluation of Gelation of Free N-Palmitoyl-Gly-His in Glycerin
Solution
[0298] Free N-palmitoyl-Gly-His prepared in Example 4 was placed
into a screw tube (Maruemu No. 1, manufactured by Maruemu Corp.).
Each of the glycerin solutions having various concentrations shown
in Table 5 was added into the screw tube so as to have a free
N-palmitoyl-Gly-His concentration of 0.2%, 0.25%, 0.5%, or 1%
(w/v). The mixture was heated at 100.degree. C. with a constant
temperature heat block (manufactured by Nippon Genetics Co., Ltd.),
and then allowed to stand at room temperature.
[0299] A state where the solution had no flowability and did not
run off even when the screw tube was placed in reverse was
determined as "gelation". The obtained results are shown in Table
5. In Table, a sample that formed a gel is shown as "O", a sample
that partially formed a gel is shown as ".DELTA.", and a sample
without evaluation is shown as "-".
TABLE-US-00005 TABLE 5 Evaluation of Gelation of Free
N-Palmitoyl-Gly-His in Glycerin Solution Mass fraction
(glycerin/water + glycerin) Pal-GH (free) concentration % (w/v) 0.1
0.3 0.4 0.5 0.6 0.7 1.0 .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. 0.5 .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. 0.25 .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. 0.2 .DELTA. .DELTA. --
.largecircle. .largecircle. .largecircle.
Example 25
Evaluation of Gelation of Free N-Palmitoyl-Gly-His in Propylene
Glycol (PG) Solution
[0300] Free N-palmitoyl-Gly-His prepared in Example 4 was placed
into a screw tube (Maruemu No. 1, manufactured by Maruemu Corp.).
Each of the propylene solutions having various concentrations shown
in Table 6 was added into the screw tube so as to have a free
N-palmitoyl-Gly-His concentration of 0.25%, 0.5%, or 1% (w/v). The
mixture was heated at 100.degree. C. with a constant temperature
heat block (manufactured by Nippon Genetics Co., Ltd.), and then
allowed to stand at room temperature.
[0301] A state where the solution had no flowability and did not
run off even when the screw tube was placed in reverse was
determined as "gelation". The obtained results are shown in Table
6. In Table, a sample that formed a gel is shown as "O", a sample
that partially formed a gel is shown as ".DELTA.", and a sample
that formed no gel is shown as "X".
TABLE-US-00006 TABLE 6 Evaluation of gelation of free
N-palmitoyl-Gly-His in PG solution Mass fraction (PG/water + PG)
Pal-GH (free) concentration % (w/v) 0.1 0.2 0.3 0.5 0.7 1.0 1.0
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. X 0.5 .DELTA. .DELTA. .largecircle. .largecircle.
.largecircle. X 0.25 .DELTA. .DELTA. .DELTA. .largecircle.
.largecircle. X
Example 26
Evaluation of Gelation of Free N-Palmitoyl-Gly-His in Solution
Containing Inorganic Salt, Amino Acid, or Organic Substance
[0302] Free N-palmitoyl-Gly-His prepared in Example 4 was placed
into a screw tube (Maruemu No. 1, manufactured by Maruemu Corp.).
An aqueous solution dissolving each additive described in Table 7
was added into the screw tube so as to have a free
N-palmitoyl-Gly-His concentration of 0.5% or 1% (w/v). The mixture
was heated at 100.degree. C. with a constant temperature heat block
(manufactured by Nippon Genetics Co., Ltd.), and then allowed to
stand at room temperature.
[0303] A state where the solution had no flowability and did not
run off even when the screw tube was placed in reverse was
determined as "gelation". The obtained results are shown in Table
7. In Table, a sample that formed a gel is shown as "O", a sample
that partially formed a gel is shown as ".DELTA.", and a sample
without evaluation is shown as "-".
TABLE-US-00007 TABLE 7 Evaluation of Gelation of Free
N-Palmitoyl-Gly-His in Solution Containing Inorganic Salt, Amino
Acid, or Organic Substance Pal-GH (free) concentration Additive %
(w/v) Additive concentration 0.5 1.0 Phenoxyethanol 0.25 wt %
.largecircle. .largecircle. Glycine 0.1 wt % .largecircle. --
Alanine 0.1 wt % .largecircle. -- Lysine hydrochloride 0.1 wt %
.DELTA. -- Aspartic acid 0.27 wt % .largecircle. -- NaCl 0.1 wt %
.DELTA. .largecircle. 0.5 wt % .largecircle. .largecircle. KCl 0.1
wt % .DELTA. .largecircle. 0.5 wt % .DELTA. .largecircle.
Example 27
Evaluation of Gelation of 0.25% (w/v) Free N-Palmitoyl-Gly-His in
Propylene Glycol Aqueous Solution (65% (w/w)) (Containing Lactic
Acid and Potassium Lactate)
[0304] Free N-palmitoyl-Gly-His (25 mg) obtained in Example 4 was
placed in a screw tube (Maruemu Corp., No. 7). Sixty-five percent
(w/w) propylene glycol aqueous solution was added so as to have a
concentration of 0.25% (w/v), and a mixture of potassium
lactate:lactic acid (95:5) was further added so as to have a
concentration of 5% (w/w) with respect to the whole solution. The
mixture was heated with a dry bath incubator (manufactured by First
Gene) at 75.degree. C. for 10 minutes. The obtained solution was
transferred into a spray vial (Maruemu Corp., No. 3L), and allowed
to cool to room temperature.
[0305] After allowing to cool, a state where the solution had no
flowability and did not run off even when the sample tube was
placed in reverse was ascertained and determined as gelation.
Example 28
Evaluation of Gelation of 0.2% (w/v) Free N-Palmitoyl-Gly-His in
Propylene Glycol Aqueous Solution (65% (w/w)) (Containing Lactic
Acid and Potassium Lactate)
[0306] Free N-palmitoyl-Gly-His (80 mg) obtained in Example 4 was
placed into a screw tube (Maruemu Corp., No. 7). Sixty-five percent
(w/w) propylene glycol aqueous solution was added so as to have a
concentration of 0.2% (w/v), and a mixture of potassium
lactate:lactic acid (95:5) was further added so as to have a
concentration of 5% (w/w) with respect to the whole solution. The
mixture was heated with a dry bath incubator (manufactured by First
Gene) at 93.degree. C. for 5 minutes. The obtained solution was
transferred into a spray vial (Maruemu Corp., No. 3L), and allowed
to cool to room temperature.
[0307] After allowing to cool, a state where the solution had no
flowability and did not run off even when the sample tube was
placed in reverse was ascertained and determined as gelation.
Example 29
Preparation of Gel and Gel Sheet Using N-Palmitoyl-Gly-His.TFA Salt
in Glycerin and Polyethylene Glycol 400 as Medium (1)
[0308] Each of the 50.4 mg of N-palmitoyl-Gly-His.TFA salt prepared
in Examples 1 to 3 was placed into a screw tube (Maruemu No. 7,
manufactured by Maruemu Corp.). Into the screw tube, 1 ml of
polyethylene glycol 400 (Wako Pure Chemical Industries, Ltd.), 1.5
ml of ethanol, and 8 ml of 70% glycerin (Junsei Chemical Co.) in
water were added so as to have an N-palmitoyl-Gly-His TFA salt
concentration of 0.5% (w/v). The mixture was heated with a dry bath
incubator (manufactured by First Gene) (105.degree. C., for 8
minutes), and then allowed to stand at room temperature to form a
gel.
[0309] Into the gel, 20 ml of Japanese Pharmacopoeia purified water
(Kyoei Pharmaceutical Industries, Ltd.) was further added and
whether sheet formation occurred or not was observed from a wide
view for 72 hours. The gels of N-palmitoyl-Gly-His.TFA salt
prepared in glycerin and polyethylene glycol 400 as a medium were
not dissolved during water immersion and the formation of a
sheet-shaped gel was observed.
Example 30
Preparation of Gel and Gel Sheet Using N-Palmitoyl-Gly-His.TFA Salt
in Glycerin and Polyethylene Glycol 400 as Medium (2)
[0310] Each of the 52.5 mg of N-palmitoyl-Gly-His.TFA salt prepared
in Examples 1 to 3 was added into a screw tube (Maruemu No. 7,
manufactured by Maruemu Corp.). Into the screw tube, 0.5 ml of
polyethylene glycol 400 (Wako Pure Chemical Industries, Ltd.), 1 ml
of ethanol, and 8 ml of 70% glycerin (Junsei Chemical Co.) in water
were added so as to have an N-palmitoyl-Gly-His.TFA salt
concentration of 0.5% (w/v). The mixture was heated with a dry bath
incubator (manufactured by First Gene) (105.degree. C., for 8
minutes), and then allowed to stand at room temperature to form a
gel.
[0311] Into the gel, 20 ml of Japanese Pharmacopoeia purified water
(Kyoei Pharmaceutical Industries, Ltd.) was further added and
whether sheet formation occurred or not was observed from a wide
view for 72 hours. The gels of N-palmitoyl-Gly-His.TFA salt
prepared in glycerin and polyethylene glycol 400 as a medium were
not dissolved during water immersion and the formation of a
sheet-shaped gel was observed.
Example 31
N-Palmitoyl-Gly-His (TFA) Gel Sheet Including Indomethacin and
I-Menthol
[0312] Each of the 50.2 mg of palmitoyl-Gly-His.TFA salt prepared
in Examples 1 to 3 was placed into a screw tube (Maruemu No. 7,
manufactured by Maruemu Corp.) together with 104.7 mg of
indomethacin and 220 mg of I-menthol. Into the screw tube, 0.5 ml
of polyethylene glycol 400 (Wako Pure Chemical Industries, Ltd.),
1.5 ml of ethanol, 8 ml of 70% glycerin (Junsei Chemical Co., Ltd.)
in water were added so as to have an N-palmitoyl-Gly-His.TFA salt
concentration of 0.5% (w/v). The mixture was heated with a dry bath
incubator (manufactured by First Gene) (105.degree. C., for 8
minutes), and then allowed to stand at room temperature to form a
pale yellow gel. The texture of the gel was smooth and cool.
[0313] After ascertainment of the gel formation, the gel was
allowed to stand at room temperature for 45 days. Then, 20 ml of
Japanese Pharmacopoeia purified water (Kyoei Pharmaceutical
Industries, Ltd.) was added and sheet formation was observed from a
wide view for 72 hours. The gel was not dissolved during water
immersion and the formation of a sheet-shaped gel was observed.
Example 32
Incorporation Test of 6-Anilino-1-Naphthalenesulfonic Acid (ANS)
into Fiber Formed by Self-Organization of N-Palmitoyl-Gly-His
Trifluoroacetate
[0314] In pH 7.5 phosphate buffer, 8-anilino-1-naphthalenesulfonic
acid (ANS) as a hydrophobic environment responsive probe was
dissolved so as to have a final concentration of 5 .mu.M. Into the
solution, N-palmitoyl-Gly-His.TFA salt prepared in Example 1 was
added so as to have a concentration of 0.5 wt % to prepare a
gel.
[0315] Separately, as controls, only N-palmitoyl-Gly-His.TFA salt
was added at a concentration of 0.5 wt % into pH 7.5 phosphate
buffer to prepare a gel, and pH 7.5 phosphoric acid aqueous
solution dissolving 5 .mu.M ANS (without N-palmitoyl-Gly-His.TFA
salt) was prepared.
[0316] On each of the gels and the solution, the fluorescence
intensity was measured (excitation wavelength (ex) at 350 nm,
fluorescence wavelength (em) at 480 nm). The obtained results are
shown in FIG. 2.
[0317] As shown in FIG. 2, 5 .mu.M ANS in pH 7.5 phosphoric acid
aqueous solution and the gel of 0.5 wt % N-palmitoyl-Gly-His (TFA)
in pH 7.5 phosphoric acid aqueous solution showed little
fluorescence intensity, but the gel of 0.5 wt % N-palmitoyl-Gly-His
(TFA) in pH 7.5 phosphoric acid aqueous solution including ANS
showed strong fluorescence intensity at around 460 nm. The results
revealed that ANS was incorporated into the fiber formed by
self-organization of N-palmitoyl-Gly-His (TFA) (inclusion compound
was formed).
[0318] In a similar manner to the above case, each of 0.5 wt %
agarose gel, 3 wt % sodium alginate gel, and 5 wt % polyacrylamide
gel was prepared using ANS that was dissolved in pH 7.5 phosphate
buffer so as to have a final concentration of 5 .mu.M. However, ANS
in each gel showed little fluorescence intensity as with ANS in the
phosphoric acid aqueous solution.
Example 33
Solubilization Test of Hydrophobic Substance by N-Palmitoyl-Gly-His
Trifluoroacetate
[0319] DL-.alpha.-tocopherol (vitamin E) as a hydrophobic substance
was dissolved in ethanol to prepare a stock solution. The stock
solution was diluted with a phosphate buffer (pH 7.5) to prepare
each sample solution having a final vitamin E concentration of 100
.mu.M to 500 .mu.M (containing 5% ethanol).
[0320] To each sample solution, N-palmitoyl-Gly-His.TFA salt
prepared in Example 1 was added (a final concentration: 0.2 wt %).
The whole was heated and dissolved, and then allowed to cool to
make a gel.
[0321] When N-palmitoyl-Gly-His.TFA salt was added, the mixture
became transparent immediately after heating, and formed no
precipitate even after allowing to cool. That is, the obtained
result revealed that vitamin E could be solubilized in the gel. In
contrast, when N-palmitoyl-Gly-His.TFA salt was not added, vitamin
E could not be solubilized and precipitates were observed.
[0322] The results show that a gel including vitamin E can be
prepared by using N-palmitoyl-Gly-His.TFA salt.
Example 34
Simultaneous Solubilization Test of Vitamin C Derivative and
Vitamin E by Free N-Palmitoyl-Gly-His
[0323] An ethanol solution of 1 wt % DL-.alpha.-tocopherol (vitamin
E) was prepared. Separately, L(+)-ascorbic acid diphosphate
trisodium (vitamin C derivative) was dissolved in a phosphate
buffer (pH 7.4) so as to have a concentration of 0.1 wt % to
prepare a stock solution. When the ethanol solution of vitamin E
and the stock solution of the vitamin C derivative were mixed at
1:99, the mixture became milky (FIG. 3(a)).
[0324] Next, free N-palmitoyl-Gly-His prepared in Example 4 was
added to the milky solution so as to have a final concentration of
1 wt %, the whole was heated with a dry bath incubator for 10
minutes so as to become a temperature of 80.degree. C. The mixture
without free N-palmitoyl-Gly-His remained milky (FIG. 3(c)). In
contrast, the mixture with free N-palmitoyl-Gly-His became clear
and colorless (FIG. 3(c)). The result revealed that vitamin E and
the vitamin C derivative could be completely and simultaneously
solubilized in the gel. The gel formed no precipitate of vitamin E
and the vitamin C derivative even when the gel was allowed to cool
to room temperature.
[0325] The results reveal that a gel simultaneously including
vitamin E and the vitamin C derivative, which have different
solubilities from each other, can be prepared by using free
N-palmitoyl-Gly-His.
Example 35
Gelation Test of Free N-Palmitoyl-Gly-His when Adding
Methylparaben
[0326] An aqueous solution of 0.2 wt % methylparaben was prepared,
and into the solution, free N-palmitoyl-Gly-His prepared in Example
4 was added so as to have a concentration of 0.25, 0.5, or 1.0 wt %
to prepare a suspended mixture solution. Each mixture solution was
heated at 95 to 99.degree. C. until dissolved (for 6 to 25
minutes), and then allowed to cool to room temperature. As a
result, a transparent gel was obtained at a concentration of 0.5 wt
% or more.
[0327] When comparing with the condition of water alone shown in
Example 23, the obtained results reveal that free
N-palmitoyl-Gly-His accelerates the dissolution of methylparaben
with poor solubility as well as improves the own gelation
properties by adding methylparaben.
[0328] Detailed mechanisms of the improvement of gelation
properties by addition of methylparaben were unknown. One of the
probable reasons is that the distance between the amide group of
the peptide bond part and the terminal carboxy group in
N-palmitoyl-Gly-His matches the distance between the hydroxy group
and the carboxy group in methylparaben, and then methylparaben
breaks in between N-palmitoyl-Gly-His molecules to form assembly
through hydrogen bonds.
[0329] Another probable reason is that the imidazole ring of
histidine in N-palmitoyl-Gly-His and the aromatic ring of
methylparaben are .pi.-stacked, a hydrogen bond is formed between
the carboxy group of methylparaben and the carboxy group of
histidine, and then the assembly of methylparaben between
N-palmitoyl-Gly-His molecules is formed.
Example 36
Preparation of Film Using N-Palmitoyl-Gly-His Trifluoroacetate
[0330] Into a screw tube (Maruemu No. 3, manufactured by Maruemu
Corp.), 3 mg of N-palmitoyl-Gly-His.TFA salt prepared in Example 1
was placed. Into the screw tube, 0.6 ml of Japanese Pharmacopoeia
purified water (Kyoei Pharmaceutical Industries, Ltd.) was added so
as to have a concentration of 0.5% (w/v). The whole was heated at
105.degree. C. for 5 minutes, and then allowed to stand at room
temperature to prepare a gel of 0.5% N-palmitoyl-Gly-His.TFA
salt.
[0331] Into the gel, 2 ml of Japanese Pharmacopoeia purified water
(Kyoei Pharmaceutical Industries, Ltd.) was further added and sheet
formation was observed from a wide view for 72 hours. The
N-palmitoyl-Gly-His (TFA) gel prepared in water as a medium did not
dissolve during water immersion and the formation of a sheet-shaped
gel was observed.
[0332] Furthermore, when the obtained gel sheet was transferred
onto a glass substrate and left in a desiccator for over ten days,
water as the medium evaporated and a film of
N-palmitoyl-Gly-His.TFA salt was prepared.
Example 37
Preparation of Glycerin Film by Free N-Palmitoyl-Gly-His
[0333] Using 10 mg of free N-palmitoyl-Gly-His, each 2.0 mL of 30%,
20%, and 10% glycerin aqueous solutions was added so as to become a
0.5% (w/v) solution, and the mixture solution was heated and
dissolved at 80.degree. C. The solution was placed in a glass petri
dish having an inner diameter of 2.2 cm and allowed to cool at room
temperature. After allowing to cool, a state where the solution had
no flowability and did not run off even when the glass petri dish
was placed in reverse was determined as gelation. Then, the
obtained gel was transferred onto a glass substrate.
[0334] The gelation was observed in each case using glycerin
aqueous solutions having the respective concentrations.
Furthermore, when the obtained sheet-shaped gel was left in a
desiccator for 10 days, a film of free N-palmitoyl-Gly-His
containing glycerin was prepared from each gel.
INDUSTRIAL APPLICABILITY
[0335] The gelator including the lipid peptide of the present
invention and the gel obtained therefrom can stably keep a gel
structure in a wide pH range from an acidic region to an alkaline
region, especially in a neutral condition, can form a gel not only
from water but also from an alcoholic solution, a hydrophilic
organic solution, a hydrophobic organic solution, a higher alcohol,
and the like and a mixed solution of such solvent and water, and
have very high biocompatibility. Thus, they are preferably used for
cosmetic base materials, quasi-drug base materials, and medical
external preparations as well as various functional materials such
as ink and paint.
[0336] For example, from the viewpoint of the application in a wide
pH range, preferred applications include detergents (for example,
for medical use, home use, and industrial use), sol-gelators (for
cosmetics and other commodities), gelators for stabilizing pigment,
food additives (for example, for acidic foods, alkaline foods, and
neutral foods).
[0337] Furthermore, in a neutral region, they can be used for
biological and biochemical materials, for example, as cell culture
carriers and base materials for skin. In an acidic region, they can
be used as base materials for pharmaceutical products such as
gastric acid-secretion inhibitors, enteric coated preparations, and
biodegradable anti-metabolic syndrome preparations for feeling of
fullness, as stabilizers and additives when producing acid milk
beverages containing pectin and the like, and for improvement of
alkali soils.
[0338] Furthermore, in an alkaline region, they can be used as
stabilizers and additives when producing alkaline beverages and
milk beverages, for catalytic reactions using various alkaline
enzymes (such as alkaline protease, alkaline cellulase, alkaline
amylase, alkaline xylase, and alkaline pectate lyase), for
industrial use of alkalophilic bacteria, as gelators used for
alkaline batteries, for improvement of acidic soils, and as base
materials, reaction additives, and accelerators in various
industrial applications such as bioreactors, detergent and soap,
cosmetics, drug discovery, and analyses and tests.
* * * * *