JPH0694451B2 - Amino acid long-chain alkyl derivative - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention produces a surfactant or amphipathic substance which forms an organic thin film or a closed type endoplasmic reticulum (liposome) in water, and acts as an emulsifier in a binary system of water and oil. The present invention relates to a highly reactive amino acid long-chain alkyl derivative useful as a synthetic intermediate. That is, the present invention relates to an amino acid long-chain alkyl derivative capable of imparting amphipathic properties by coupling with various hydrophilic substances. Industrial applications of this invention include thin film-forming materials in the fields of medicine and cosmetics, foods as synthetic intermediates for liposome film-forming materials,
It is suitable as a synthetic intermediate for textile industry, emulsifiers such as dyes, stabilizers, dispersants, and wetting agents.

[0002]

2. Description of the Related Art In the prior art, natural phospholipid derivatives, surfactants and various synthetic amphiphiles have been obtained from glycerin, which is a polyhydric alcohol, as a raw material (eg, procedurals off).・ National Acatemy of Science of USA (Proc. Natl. Acad. Sci. USA) No. 7
Volume 4, page 4315 (1977)). However, when an amphipathic substance is produced using glycerin, one of three hydroxyl groups is reacted with a hydrophilic group, and the remaining two hydroxyl groups are hydrophobic such as two long-chain acyl groups. Since it had to react with the sex group, the synthetic route was complicated and the reaction was difficult to control.

[0003]

DISCLOSURE OF THE INVENTION The present inventor is a substance as a synthetic intermediate for producing a surfactant or an amphipathic substance, which contains an arbitrary long-chain alkyl group in advance and is easy to synthesize and react. As a result of intensive studies to develop a compound having high activity, it was found that amino acid long-chain alkyl derivatives derived from serine or aspartic acid can meet the purpose, and based on this finding, the present invention was completed. It was

[0004]

That is, the present invention provides a general formula

Embedded image (X is a hydroxymethyl group or a carboxyl group, Y is an oxygen atom constituting an ester group or an NH atom constituting an amide group, and R and R ′ have 12 to 12 carbon atoms.
The present invention provides an amino acid long-chain alkyl derivative represented by 18 long-chain alkyl groups).

X in the general formula (1) is a hydroxymethyl group or a carboxyl group. Y is an oxygen atom forming an ester group or an NH atom forming an amide group. R is a long-chain alkyl group having 12 to 18 carbon atoms, and examples thereof include dodecyl group, tetradecyl group, hexadecyl group, octadecyl group and the like.

The compound represented by the general formula (1) is
Both are novel compounds not described in the literature. For example, serine with protected amino and hydroxyl groups is reacted with a long-chain alkylamine or a long-chain alkyl alcohol to obtain a single-chain amide or a single-chain ester, respectively. Then, the N-terminal protecting group is removed, a long-chain fatty acid is reacted therewith to obtain a double-chain serine long-chain dialkyl derivative, and finally the hydroxyl-protecting group is eliminated. Similarly, aspartic acid with protected amino and carboxyl groups is reacted with a long-chain alkylamine or a long-chain alkyl alcohol to obtain a single-chain amide or a single-chain ester, respectively. Is removed, a long-chain fatty acid is reacted therewith to obtain a double-chain type long-chain dialkyl derivative of aspartic acid, and finally the protecting group of the carboxyl group is eliminated.

As a protecting group for an amino group, a t-butyloxycarbonyl group, a benzyloxycarbonyl group, a p-methoxybenzyloxycarbonyl group, an o-nitrophenylsulfenyl group and a hydroxyl group, which are commonly used in peptide synthesis, are used. A benzyl group or the like can be used as the protective group of. As the protective group for the carboxyl group, a benzyl ester group, a p-nitrobenzyl ester group, a p-methoxybenzyl ester group or the like can be used. Dodecylamine, tetradecylamine, hexadecylamine, octadecylamine can be used as the long-chain alkylamine, and dodecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol, etc. can be used as the long-chain alkyl alcohol. As the long chain fatty acid, myristic acid, palmitic acid, stearic acid, etc. can be used.

Solvents for amide bond formation reactions using long-chain alkylamines or long-chain fatty acids include methylene chloride, chloroform, dimethylformamide (DMF),
Dioxane and tetrahydrofuran (THF) can be used. In a DMF / chloroform mixed solvent system, using diethylphosphorus cyanidate as the condensing agent gives good yields. On the other hand, as a solvent for the ester bond formation reaction using a long-chain alkyl alcohol,
Methylene chloride, chloroform, DMF, dioxane, T
HF can be used. Methylene chloride is suitable from the viewpoint of solubility. In this case, water-soluble carbodiimide as a condensing agent and dimethylaminopyridine as a catalyst give a good yield. All the synthetic intermediates are washed with an acid and an alkali, and recrystallized from a suitable solvent,
It can be easily isolated and purified.

Coupling of the compounds of the invention with other compounds is possible with any hydrophilic compound. In particular, amino acid long-chain alkyl derivatives containing a hydroxymethyl group are useful as an aglycone component in an O-glycoside bond forming reaction with a sugar residue. Furthermore, for amino acid long-chain alkyl derivatives containing a carboxyl group, coupling with hydrophilic substances such as amino acids, peptides, and sugars containing an amino group at the terminal can be applied to abundant coupling agents, and the reactivity is good. It is convenient in terms of things.

The measured elemental analysis values of the compounds of the present invention agree with the calculated values within an error range. Further, in the infrared absorption spectrum, the characteristic absorption derived from the ester carbonyl group is shown at 1730 to 1750 cm ^-1, and the characteristic absorption derived from the amidocarbonyl group is shown at 1640 to 1660 cm ^-1 . ^{In 13} C-NMR, δ value is 14 ppm, 23 ppm, 26 ppm, 28 ppm, 30 ppm, 32 ppm
(All of these are carbons of methylene and methyl of long-chain alkyl group), 35-37ppm (carbon of methylene group adjacent to carbonyl group of aspartic acid Cβ carbon and long-chain acyl group), 39-40ppm (α-amide group Carbon of methylene group adjacent to), 48-49ppm (Cα carbon aspartic acid), 53
-54ppm (serine Cα carbon), 63-64ppm (serine Cβ carbon), 171ppm (α-amide group carbonyl carbon and ester group carbonyl carbon), 174ppm (N-acyl group carbonyl carbon and carboxylate carbonyl carbon) signals observed The product can be identified and confirmed by the above.

[0011]

EXAMPLES Next, the present invention will be described in more detail by way of examples and application examples.

Example 1 Method for producing N-tetradecanoyl-L-serine-dodecyl ester t-butyloxycarbonyl-O-benzyl-L-serine
2.0 g (6.8 mmol) and dodecyl alcohol 1.39 g (7.45 mmol) were dissolved in methylene chloride (20 ml), catalytic amount of dimethylaminopyridine and 1.43 g (7.45 mmol) of water-soluble carbodiimide were added, and the mixture was kept at 0 ° C for 3 hours. Then, the mixture was stirred overnight at room temperature. The reaction mixture was washed with 4% aqueous sodium hydrogen carbonate solution, 10% aqueous citric acid solution and water in this order. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The colorless oil obtained was rubbed in water to obtain a white semi-solid t-butyloxycarbonyl-O-benzyl-L-serine-dodecyl ester. This was dissolved in ethyl acetate (5 ml) and a 4N-hydrogen chloride / ethyl acetate solution (50 ml) was allowed to act at room temperature for 1 hour to give O-benzyl-L-serine-dodecyl ester hydrochloride 2.2.
2 g (5.55 mmol) was obtained. 1.06 g of myristic acid (4.6
It was dissolved in DMF (20 ml) together with 2 mmol) and 0.95 g (5.55 mmol) diethylphosphorocyanidate and 1.42 ml (10.2 mmol) triethylamine were added. After stirring at 0 ° C. for 3 hours, the mixture was stirred at room temperature for 24 hours. The mixture was diluted with chloroform, and washed with 4% sodium hydrogen carbonate aqueous solution, 10% citric acid aqueous solution, and water in this order. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The colorless gel-like solid obtained was crystallized from water / acetone to give N-tetradecanoyl-O-benzyl-L.
-Serine-dodecyl ester 2.47 g (yield 93%) was obtained. Removal of O-benzyl group is carried out by catalytic reduction of 1.23 g (2.14 mmol) of this compound in 120 ml of t-butanol / chloroform (5/7, volume ratio) with 5% -palladium carbon as a catalyst for about 10 hours. Completed by The reaction mixture was filtered and the solvent was distilled off to obtain a white residue. This was recrystallized from warm ethanol to give the target compound 82, mp 73-75 ° C.
0 mg (79% yield) was obtained as a white powder. ^{13 of} this thing
The C-NMR spectrum (in deuterated chloroform, 25 ° C.) is
Methyl group carbon of long-chain alkyl group, 22.6 at 14.05ppm in δ value
-36.5ppm methylene carbon of long chain alkyl group, 54.8ppm serine Cα carbon, 63.8ppm serine Cβ carbon, 66.1ppm methylene group carbon adjacent to the ester group, 170.6ppm ester carbonyl carbon, 173.8ppm Shows the signals that can be assigned to the carbons of the amide carbonyl group. Elemental analysis value (as C ₂₉ H ₅₇ O ₄ N ・ 1 / 4H ₂ O) C H N calculated value (%) 71.34 11.87 2.87 Measured value (%) 71.05 11.56 2.96

[0012]

Example 2 Method for producing Nα-tetradecanoyl-N-dodecyl-L-serinamide t-butyloxycarbonyl-O-benzyl-L-serine
2.0 g (6.8 mmol) and dodecylamine 1.26 g (6.77 mmol) were dissolved in DMF / chloroform (= 5, volume ratio) (60 ml), and diethylphosphorocyanidate 1.40 g (8.13 mmol) and triethylamine 1.14 ml ( 8.13 mmol),
The mixture was stirred at 0 ° C. for 3 hours, and then at room temperature overnight. The reaction mixture was washed with 10% aqueous citric acid solution, saturated brine, 4% aqueous sodium hydrogen carbonate solution and water in this order. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The colorless oil obtained was rubbed in water / methanol (= 1, volume ratio) to give a melting point of 48-50.
C. white solid N.alpha.-t-butyloxycarbonyl-N
-Dodecyl-O-benzyl-L-serinamide was obtained.
This was dissolved in ethyl acetate (10 ml) and 4N-hydrogen chloride /
Ethyl acetate solution (33 ml) was allowed to act at room temperature for 1 hour to give N-
Dodecyl-O-benzyl-L-serinamide hydrochloride 1.75
g (4.32 mmol) was obtained as a colorless syrup. This was dissolved in DMF (30 ml) together with 0.82 g (3.60 mmol) of myristic acid, and 0.74 g (4.32 mmol) of diethyl phosphorocyanidate and 1.11 ml (7.92 mmol) of triethylamine were added. After stirring at 0 ° C. for 3 hours, the mixture was stirred at room temperature for 24 hours. The mixture was diluted with chloroform, and washed with 4% sodium hydrogen carbonate aqueous solution, 10% citric acid aqueous solution, and water in this order. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained pale yellow gel-like solid was crystallized from acetone and Nα-having a melting point of 94-95 ° C.
Tetradecanoyl-N-dodecyl-O-benzyl-L-
1.44 g of serinamide was obtained as a white solid. O-benzyl group was removed by catalytic reduction of 0.80 g (1.40 mmol) of this compound in 80 ml of ethyl acetate / ethanol / chloroform (1/1/2, volume ratio) using 5% palladium carbon as a catalyst. Completed by doing time. The reaction mixture was filtered and the solvent was distilled off to obtain a white residue. This was recrystallized from warm ethanol to give the target compound with a melting point of 123-124 ° C.
0 mg (68% yield) was obtained as a white powder. ^{13 of} this thing
The C-NMR spectrum (in deuterated chloroform, 35 ° C.) is
Methyl group carbon of long chain alkyl group at δ value 14.02ppm, 22.6
~ 39.5ppm long chain alkyl group methylene carbon, 53.5ppm serine Cα carbon, 62.8ppm serine Cβ carbon, 171.1ppm
Shows the signals that can be assigned to the carbon of the carbonyl group adjacent to the Cα carbon and 174.3 ppm to the carbonyl carbon of the tetradecanoyl group, respectively. Elemental analysis value (as C ₂₉ H ₅₈ O ₃ N ₂ ) C H N calculated value (%) 72.15 12.11 5.80 Measured value (%) 71.87 11.77 6.09

[0013]

Example 3 Method for producing N-tetradecanoyl-L-aspartic acid-α-dodecyl ester t-butyloxycarbonyl-L-aspartic acid-β-
3.0 g (9.28 mmol) of benzyl ester and 1.90 g (10.00 mmol) of dodecyl alcohol were dissolved in methylene chloride (20 ml), a catalytic amount of dimethylaminopyridine and 1.96 g (10.20 mmol) of water-soluble carbodiimide were added, and the mixture was stirred at 0 ° C. The mixture was stirred for 3 hours, then at room temperature for 24 hours. The reaction mixture was washed with 4% aqueous sodium hydrogen carbonate solution, 10% aqueous citric acid solution and water in this order. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The pale yellow oil obtained was washed with hexane to give a colorless oil.
t-Butyloxycarbonyl-L-aspartic acid-β-
Benzyl ester-α-dodecyl ester was obtained. This was dissolved in ethyl acetate (5 ml) and a 4N-hydrogen chloride / ethyl acetate solution (69 ml) was allowed to act at room temperature for 1 hour to allow L-aspartic acid-β-benzyl ester-α-dodecyl ester hydrochloride 3.97 g (9.15 (Mmol). This was dissolved in DMF (20 ml) together with 1.74 g (7.63 mmol) myristic acid, and 1.57 g (9.15 mmol) diethylphosphorocyanidate and 2.35 ml (16.8 mmol) triethylamine were added.
After stirring at 0 ° C. for 3 hours, the mixture was stirred at room temperature for 24 hours. The mixture was diluted with chloroform, and washed with 4% sodium hydrogen carbonate aqueous solution, 10% citric acid aqueous solution, and water in this order. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained pale yellow solid was crystallized from hexane / acetone to give 4.42 g (yield 95%) of N-tetradecanoyl-L-aspartic acid-β-benzyl ester-α-dodecyl ester having a melting point of 64-65 ° C. Obtained. 1.72 g of this compound was removed from the benzyl ester group.
(2.86 mmol) was added to t-butanol / chloroform (= 1,
This was completed by carrying out catalytic reduction for about 10 hours using 5% -palladium carbon as a catalyst in 100 ml (volume ratio). The reaction mixture was filtered and the solvent was distilled off to obtain a pale yellow residue. This was recrystallized from warm ethanol to obtain 980 mg (yield 67%) of the target compound having a melting point of 65 to 68 ° C as a white powder. ¹³ C-NMR spectrum of this product (25% in deuterated chloroform)
C) is 14.05 ppm in terms of δ value, methyl group carbon of long-chain alkyl group, 22.6-36.4 ppm in methylene carbon of long-chain alkyl group, 3
6.2 ppm aspartic acid Cβ carbon, 8.3 ppm aspartic acid Cα carbon, 66.1 ppm as methylene group carbon adjacent to α-ester group, 170.7 ppm as α-ester carbonyl group carbon, 173.5 ppm as amidocarbonyl group carbon , 174.9p
The signals that can be assigned to the carbons of the free carboxylic acid carbonyl group are shown in pm. Elemental analysis value (as C ₃₀ H ₅₇ O ₅ N ・ 1 / 4CH ₃ COOH) C H N calculated value (%) 67.95 10.86 2.52 Measured value (%) 68.12 10.62 2.66

[0014]

Example 4 Method for producing Nα-tetradecanoyl-N-dodecyl-L-aspartic acid-α-amide t-butyloxycarbonyl-L-aspartic acid-β-
3.0 g (9.28 mmol) of benzyl ester and dodecylamine 1.
72 g (9.28 mmol) was dissolved in DMF (80 ml), diethylphosphorocyanidate (1.91 g) (11 mmol) and triethylamine (1.56 ml (11 mmol)) were added, and the mixture was stirred at 0 ° C. for 3 hours and then at room temperature overnight. I spilled. The reaction mixture was washed with 10% aqueous citric acid solution, saturated brine, 4% aqueous sodium hydrogen carbonate solution and water in this order. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The pale yellow syrup obtained was rubbed in water to give Nα-t-butyloxycarbonyl-
N-dodecyl-L-aspartic acid-β-benzyl ester-α-amide was obtained as a white solid. This was dissolved in ethyl acetate (10 ml), and 4N-hydrogen chloride / ethyl acetate solution (50 ml) was allowed to act at room temperature for 1 hour to give N-dodecyl-L.
2.61 g (6.11 mmol) of aspartic acid-β-benzyl ester-α-amide hydrochloride were obtained as a pale yellow syrup. D with myristic acid 1.16 g (5.09 mmol)
It was dissolved in MF (20 ml) and 1.05 g (6.11 mmol) of diethylphosphorus cyanidate and 1.57 ml (11.0 mmol) of triethylamine were added. After stirring at 0 ° C. for 3 hours, the mixture was stirred at room temperature for 24 hours. The mixture was diluted with chloroform, and washed with 4% sodium hydrogen carbonate aqueous solution, 10% citric acid aqueous solution, and water in this order. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained pale yellow solid was crystallized from acetone, and 1.96 g (yield 64%) of Nα-tetradecanoyl-N-dodecyl-L-aspartic acid-β-benzyl ester-α-amide having a melting point of 100 to 102 ° C. Was obtained as a white solid. Benzyl ester group was removed by adding 1.00 g (1.66 mmol) of this compound to ethanol /
It was completed by catalytic reduction in 100 ml of chloroform (2/3, volume ratio) with 5% palladium carbon as a catalyst for about 3 hours. The reaction mixture was filtered and the solvent was distilled off to obtain a white residue. This is recrystallized from warm ethanol,
600 mg (yield 71%) of the target compound having a melting point of 107-109 ° C was obtained as a white powder. The ¹³ C-NMR spectrum (in deuterated chloroform, 35 ° C.) of this product showed that the δ value was 14.02 ppm at the methyl group carbon of the long chain alkyl group, 22.6-39.9 ppm at the methylene carbon of the long chain alkyl group, and 36.2 ppm at aspartic acid. Cβ
Carbon, carbon at 49.2 ppm, carbon atom of aspartic acid Cα, carbon at carbonyl group adjacent to Cα carbon at 170.7 ppm, and signal at 174.0 ppm for carbonyl carbon of tetradecanoyl group and carbon of free carboxylic acid carbonyl group, respectively. Elemental analysis value (as C ₃₀ H ₅₈ O ₄ N ₂ ) C H N calculated value (%) 70.54 11.45 5.48 Measured value (%) 70.42 11.26 5.72

[0015]

Example 5 In the same manner as in Examples 1 and 3, octadecyl alcohol having a different alkyl chain length was used instead of dodecyl alcohol, and stearic acid having a different alkyl chain length was used instead of myristic acid. The compound shown was obtained. N-octadecanoyl-L-serine-octadecyl ester melting point 112-115 ° C N-octadecanoyl-L-aspartic acid-α-octadecyl ester melting point 105-108 ° C

[0016]

Example 6 Compounds shown below were prepared in the same manner as in Examples 2 and 4, except that octadecylamine having a different alkyl chain length was used instead of dodecylamine and stearic acid having a different alkyl chain length was used instead of myristic acid. Got Nα-octadecanoyl-N-octadecyl-L-serinamide melting point 175-178 ° C Nα-octadecanoyl-N-octadecyl-L-aspartic acid-α-amide melting point 152-155 ° C

[0017]

[Application Example 1] N-tetradecanoyl-O- (β-D-
Method for producing glucopyranosyl) -L-serine-dodecyl ester 400 mg of powder of molecular sieve 4A was dried by heating in a reaction flask under reduced pressure, and naturally cooled to an argon atmosphere. In addition to this, N-tetradecanoyl-L-serine-
A solution of 289 mg (0.59 mmol) of dodecyl ester (Example 1) in methylene chloride (5.0 ml) was added. After stirring for 30 minutes, a solution of tetra-O-acetyl-α-D-glucopyranosyl-trichloroacetimidate (289 mg, 0.59 mmol) in methylene chloride (2 ml) was added. A solution of trimethylsilyl trifluoromethanesulfonate (260 mg, 1.17 mmol) in methylene chloride (1.7 ml) was added while the reaction flask was cooled to 0 ° C., and the mixture was stirred at 0 ° C. for 3 hours. After adding saturated aqueous sodium hydrogen carbonate solution (10 ml) at 0 ° C., the solution was diluted with 50 ml of chloroform at room temperature. The suspension was filtered over Celite and washed with 30 ml of saturated aqueous sodium chloride solution. The organic layer was separated, dried over anhydrous sodium sulfate and filtered, and then the solvent was evaporated under reduced pressure. The remaining pale yellow gel was subjected to silica gel column chromatography (gradient elution from toluene / acetone = 15 (volume ratio) to toluene / acetone = 4 (volume ratio)).
120 mg (yield 26%) of N-tetradecanoyl-O- (tetra-O-acetyl-β-D-glucopyranosyl) -L-serine-dodecyl ester having a melting point of 68 to 69 ° C. as a white powder. Got as.

After dissolving 115 mg (0.141 mmol) of this compound in 5.0 ml of methanol, a solution of 1% sodium methoxide in methanol was added until the pH of the system reached about 8.5 (about 4
Drop) added. After stirring at room temperature for 30 minutes, a strong acid cation exchange resin (proton type) was added to neutralize. After diluting with chloroform, the solvent was distilled off under reduced pressure to obtain a white solid. Finally, the product was purified by silica gel column chromatography (chloroform / methanol = 9 (volume ratio)) to give a melting point of 116 to 117 ° C. and a specific optical rotation [α] _D = −.
9.9 ° (c = 1.0 in chloroform) N-tetradecanoyl-O- (β-D-glucopyranosyl) -L-serine-
50 mg (55% yield) of dodecyl ester was obtained as a white powder. Elemental analysis (as _{C 35 H 67 O 9 N)} C H N calc (%) 65.08 10.46 2.17 Found (%) 64.82 10.55 2.29

[0019]

[Application Example 2] Method for producing Nα-tetradecanoyl-N- (tetra-O-acetyl-β-D-galactopyranosyl) -L-asparagine-dodecyl ester β-D-galactosylamine 280 mg (0.81 mmol) Dissolved in 10 ml of chloroform / ethanol (5/1, volume ratio),
220 mg (0.88 mmol) of 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroxyquinoline and 410 mg (0.80 mmol) of N-tetradecanoyl-L-aspartic acid-α-dodecyl ester (Example 3) were added at room temperature. I stird all day and night. After the solvent was distilled off, chloroform was added to the residue, and the mixture was washed with ice water, 7% hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution, and ice water in this order. The organic layer was separated, dried over anhydrous sodium sulfate and filtered, and then the solvent was evaporated under reduced pressure. The remaining colorless syrup was subjected to silica gel column chromatography (methylene chloride / acetone = 20 (volume ratio)).
The desired compound (500 mg, yield 75
%) As a colorless syrup. Elemental analysis (C ₄₄ as _{H 76 O 13 N 2) C} H N calc (%) 62.83 9.11 3.33 Found (%) 62.50 9.35 3.05

[0020]

Since the compound of the present invention already contains a long chain alkyl group as a hydrophobic group in its structure, it is coupled with a chemical substance from a low molecule to a polymer containing a hydrophilic residue. By doing so, a wide range of functional surfactants and amphipathic substances can be easily obtained.

Claims (1)

[Claims] 1. A general formula: (X is a hydroxymethyl group or a carboxyl group, Y is an oxygen atom forming an ester group or an NH atom forming an amide group, and R and R ′ are long-chain alkyl groups having 12 to 18 carbon atoms. ) An amino acid long-chain alkyl derivative represented by: