WO2006001345A1

WO2006001345A1 - L-lysine·citric acid salt crystal

Info

Publication number: WO2006001345A1
Application number: PCT/JP2005/011557
Authority: WO
Inventors: Hideki Murata; Yu Yamamoto
Original assignee: Kyowa Hakko Kogyo Co., Ltd.
Priority date: 2004-06-23
Filing date: 2005-06-23
Publication date: 2006-01-05
Also published as: JPWO2006001345A1; JP4796493B2

Abstract

Disclosed are a crystal of a salt composed of L-lysine and citric acid, a crystal of a salt composed of L-lysine and citric acid whose 5 weight% aqueous solution has a pH of 3-6, a crystal of a salt composed of L-lysine and citric acid wherein the composition ratio (molar ratio) between L-lysine and citric acid is 2:1, a method for producing a crystal of a salt composed of L-lysine and citric acid which is characterized in that L-lysine and citric acid are dissolved in water and a crystal is separated from the thus-obtained aqueous solution, and such a method for producing a crystal of a salt composed of L-lysine and citric acid wherein the aqueous solution has a pH of 3-6.

Description

L-lysine succinate crystals

Technical field

[0001] The present invention relates to crystals of L-lysine and a salt (L-lysine 'citrate) having citrate power and a method for producing the same.

Background art

[0002] L-Lysine is one of the essential amino acids and is widely used for nutritional supplements and pharmaceuticals. L-lysine is also used as a feed additive because it is a restricted amino acid in feed corn.

The free base of L-lysine is difficult to isolate as crystals and the crystals are highly hygroscopic and absorb carbon dioxide in the air and are difficult to handle. Therefore, L-lysine is usually distributed in the form of salt such as hydrochloride (Sigma Product Catalog 2004-2005 edition).

[0003] When L-lysine is used as a component such as an infusion solution for the purpose of nutrition intake, for example, if hydrochloride is used as it is, it may cause acidosis symptoms. In addition, administration of an infusion solution containing a large amount of chloride ions is preferable particularly for patients with renal diseases. Furthermore, when L-lysine is mixed with food as a nutritional supplement or used as it is orally, it is well known that, for example, hydrochloride is difficult to use due to its bitter taste.

[0004] As salts of L-lysine, in addition to the above-mentioned hydrochlorides, for example, acetate (Sigma Product Catalog 2004-2005 edition), malate (see Patent Documents 1 and 2), aspartate (non-patented) Reference 1) are known as crystals.

On the other hand, it is known that it can be used as a salty taste improving agent for lysine and citrate, but its crystal is not known (see Patent Document 3).

Patent Document 1: Japanese Patent Laid-Open No. 62-174043

Patent Document 2: JP-A-55-69546

Patent Document 3: JP 2003-144088 Non-Patent Document 1: “Acta Crystallographica, Section B: Structural Crystallography and Crystal Chemistry”, 1976, p. 891, p. 891

Disclosure of the invention

Problems to be solved by the invention

[0005] An object of the present invention is to provide a crystal of L-lysine 'citrate excellent as a source of L-lysine and a method for producing the same.

Means for solving the problem

[0006] The present invention relates to the following (1) to (11).

(1) L-lysine and salt crystals that have citrate power.

(2) The crystal according to (1), wherein the pH of a 5% by weight aqueous solution of the crystal is 3 to 6.

(3) The crystal according to (1), wherein the composition ratio of L-lysine and citrate is 2: 1 (molar ratio).

(4) The method for producing a crystal according to any one of (1) to (3), wherein L-lysine and citrate are dissolved in water and the crystal is precipitated from the obtained aqueous solution.

(5) The method according to (4), wherein the pH of the aqueous solution is 3 to 6.

(6) The production method according to (4), wherein the pH of the aqueous solution is 4.5 to 5.5.

(7) The production method according to any one of (4) to (6), wherein the method for precipitating the crystal includes a step of adding a hydrophilic organic solvent to the aqueous solution.

(8) The method according to any one of (4) to (6), wherein the method for precipitating the crystal is a method including a step of adding an aqueous solution to a hydrophilic organic solvent.

(9) The production method according to (7) or (8), wherein the hydrophilic organic solvent is an alcohol organic solvent, an amide solvent, acetone, or acetonitrile.

(10) The hydrophilic organic solvent is methanol, ethanol, propanol, isopropyl alcohol, butanol, ethylene glycol, diethylene glycol, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, acetone, and acetone. The production method according to (7) or (8), wherein the group force is a nitrile force.

(11) Hydrophilic organic solvent power The product according to (7) or (8), which is ethanol or ethanol Manufacturing method.

The invention's effect

[0007] According to the present invention, L-lysine 'citrate crystals excellent as a source of L-lysine and a method for producing the same are provided.

Brief Description of Drawings

[0008] FIG. 1 shows the results of a hygroscopicity test of the L-lysine 1Ζ2 citrate crystals obtained in Example 1. In the figure, the horizontal axis shows the number of days (days) since the start of the test, and the vertical axis shows the moisture absorption (%). EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] The crystal of L-lysine 'citrate of the present invention is preferably composed of 0.5 to 3 moles of L-lysine and 1 mole of citrate, and more preferably 2 moles of L-lysine and 1 mole of L-lysine. Consists of citrate. The aqueous solution is also acidic in neutrality, and in a 5 wt% aqueous solution, ρΗ is 3 to 7, preferably 3 to 6, more preferably 4.5 to 5.5, most preferably 4.8 to 5.0. Indicates.

The crystal usually exists alone, but can also exist as a solvate with water or various organic solvents, and these solvates are also encompassed in the present invention.

[0010] Examples of the hydrophilic organic solvent used in the present invention include alcohol-based organic solvents such as methanol, ethanol, phenol, isopropyl alcohol, butanol, ethylene glycolanol, and diethylene glycol, Ν, ジメチル dimethylformamide, Ν , アミド Organic solvents such as dimethylacetamide and メチル -methylpyrrolidone, acetonitrile, acetone and the like are preferable, and methanol, ethanol and the like are preferable, and these are used alone or in combination.

Next, the method for producing the L-lysine 'citrate crystal of the present invention will be described.

For example, an aqueous solution containing free L-lysine is obtained by treating commercially available L-lysine hydrochloride or the like with a strongly acidic ion exchange resin. To the resulting aqueous solution containing free L-lysine, add citrate and dissolve. For example, when it is desired to obtain crystals of the present invention in which the composition ratio of L-lysine and citrate is 2: 1 (molar ratio), L-lysine is 0.3 to L equivalent, preferably 0. 4 to 0.6 equivalents, most preferably 0.5 equivalents, and the resulting aqueous solution For example, 3 to 7, preferably 3 to 6, more preferably 4.5 to 5.5, and most preferably 4.9.

[0012] By concentrating the obtained aqueous solution as it is, it is possible to obtain crystals of L-lysine 'citrate. However, after the aqueous solution is concentrated to a high concentration, it becomes a viscous liquid. , L-lysine 'kenate tends to precipitate as a lump and often difficult to separate.

Therefore, in order to obtain crystals efficiently, for example, the aqueous solution is cooled to −10 to 20 ° C., seed crystals are added to the aqueous solution, or a hydrophilic organic solvent is added to the aqueous solution. It is preferable to precipitate and isolate the crystals by adding the aqueous solution to a hydrophilic organic solvent. Alternatively, crystals can also be precipitated by combining these methods. When a hydrophilic organic solvent is added to the aqueous solution, or when the aqueous solution is added to the hydrophilic organic solvent, crystals may partially precipitate in the aqueous solution.

[0013] When a crystal is precipitated by adding a hydrophilic organic solvent to the aqueous solution, the aqueous solution is concentrated so that the concentration of L-lysine.kenate is 30 to 70%, preferably 40 to 70%. It is preferable to use it after adjusting it. The use of an aqueous solution having a concentration of 30% or more is more preferable because the amount of the hydrophilic organic solvent used for precipitating crystals can be reduced. Further, when an aqueous solution having a concentration of 70% or less is used, the miscibility between the aqueous solution and the hydrophilic organic solvent becomes easy, and crystal precipitation is more easily induced. In addition, it is easy to avoid the precipitated crystals from becoming block-like lumps. The hydrophilic organic solvent is usually 1 to 8 times the amount of the above-adjusted aqueous solution (water content is 50% to 11%), preferably 1.5 to 5 times (water content force S40 to 17). And is added by gradually adding or dropping it to an aqueous solution adjusted to the above concentration at 10 ° C to 60 ° C, preferably at room temperature to 50 ° C. Crystals may be precipitated just by adding a hydrophilic organic solvent, but usually the resulting mixture is at −10 ° C. to 50 ° C., preferably at −10 ° C. to room temperature for 5 minutes to Precipitate by stirring for 72 hours. In addition, it is also possible to induce crystal precipitation by separately adding the crystal obtained in the present invention as a seed crystal to the obtained mixed solution. The seed is sufficient if it can induce crystallization. The amount of L-lysine 'citrate contained in the mixture is 0.01. ~ 0.1%, preferably 0.05% is used.

[0014] When the above aqueous solution is added to a hydrophilic organic solvent to precipitate crystals, the mixture is stirred at -10 ° C to 60 ° C, preferably -10 ° C in the hydrophilic organic solvent. Crystals can be precipitated by adding dropwise an aqueous solution having the same concentration as described above at room temperature. The hydrophilic organic solvent is usually used in an amount of 1 to 8 times that of the aqueous solution with the above concentration adjusted. The precipitated crystals are separated by a method such as filtration, and dried to obtain L-lysine 'citrate crystals.

[0015] Next, the hygroscopicity of the L-lysine 'citrate crystals of the present invention will be described with reference to test examples.

Test example 1

(Approximately 200mL of saturated aqueous sodium chloride solution was left in a plastic desiccator for 24 hours at 25 ° C. Adjusting the humidity to 75%). 2 g of the crystals obtained in Example 1 were weighed into a glass jar. The weighed bottle was weighed and left in the desiccator with the above humidity adjusted, and the weight change of the bottle was measured over time.

[0016] Based on the weight change at each time point measured, the hygroscopicity (hygroscopicity) was calculated using the following equation (1). The weight change of the force bottle was measured until the 7th day.

[0017] [Equation 1]

W 3 -W 2,,

Hygroscopicity (./.) = 1 0 0 (1)

W 2 -W 1

[0018] W1: Weight of scale bottle (g)

W2: Weight of test bottle with crystals before test (g)

W3: Weight of test bottle with crystals after test (g)

The results are shown in Figure 1.

The crystals of L-lysine · ckenate obtained in Example 1 did not show significant hygroscopicity. That is, it was shown that the L-lysine 'citrate of the present invention does not require special attention to moisture during storage.

[0019] As indicated above, the L-lysine 'citrate crystals of the present invention can be stored at room temperature in the atmosphere. Also, do not use corrosive chemicals such as hydrochloric acid in the manufacturing process. In addition, citrate is an excellent source of L-lysine because it is less expensive than L-malic acid.

In addition, L-lysine 'citrate crystals are expected to be more combined with the properties of L-lysine in addition to the inherent properties of L-lysine. Quenic acid is an intermediate of the citrate cycle (TCA cycle), and its activity can be expected to promote fatty acid synthesis and recover from fatigue by eliminating accumulated lactic acid. Furthermore, improvement of the bitterness of hydrochlorides is also expected. In other words, crystals of L-lysine 'citrate are expected to be used as a better source of L-lysine in nutritional supplements, pharmaceuticals, and feeds.

Example 1

[0020] 20 g of L-lysine hydrochloride (16 Og as free L-lysine) was dissolved in 400 mL of water, and passed through a column packed with 200 mL of strong acid ion-exchanged resin (Marathon C) (H type). After washing the resin with 200 mL of water, L-lysine was eluted with 400 mL of 2 mol ZL aqueous ammonia. Concentrate the eluate to about 200 mL under reduced pressure, and then add 10.5 g of citrate (0.5 equivalent to L-lysine) to the resulting L-lysine aqueous solution (containing 0.1-109 mol of L-lysine). As a result, the pH of the aqueous solution was adjusted to 4.9. The resulting aqueous solution was concentrated under reduced pressure to a total volume of 38 mL, and then 57 mL of ethanol was gradually added while stirring at room temperature. After further stirring at room temperature for 8 hours, the precipitated crystals were collected by filtration and washed with ethanol. The obtained crystals were dried under reduced pressure at 20 ° C. overnight to obtain 24.8 g (yield: 93.4%) of L-lysine 1/2 queenate crystals as pale yellow needles.

Melting point: 208.8 ° C (decomposition)

Infrared absorption spectrum (KBr, cm " ¹ ): 1585.4, 1403.1, 1142.7, 995.2, 861.2 Powder X-ray crystallographic analysis: RAD— X-type (manufactured by Rigaku Corporation). The results are shown in Table 1.

[0021] [Table 1] Table 1

Analysis angle (2 (sheet)) Peak strength (ίΐίί bow

4.65 36

760

1100 1C0

13-90 36

1 41

7S

19.00 74

20,55 90

Four'::

[0022] Crystal composition analysis: shown in Table 2.

[0023] [Table 2] Table 2

Actual measurement (¾) Total !: Value <%) ^:

L-Lysine (%) 6 C. C 6 C 4 Quen ^ (%) C.C 3 6

(Note)-: For each measurement, high-speed liquid chromatography (HPLC) was used. For L-resin, OP color development method (excitation wavelength: 34 On in, fluorescence growth: 455 nm). ^ Is analyzed by UV detection method (detection wavelength: 210 nm)! ;

…: The total value is given as (C _s H ₁₄ N ₃ 0 ₌ ) ₂ · C _B H _s O _τ : g:

Example 2

[0024] By adding 10.5 g of citric acid (0.5 equivalent to L-lysine) to an L-lysine aqueous solution (containing 0.109 mol of L-lysine) obtained in the same manner as in Example 1, The pH of the aqueous solution was adjusted to 4.9. The resulting aqueous solution was concentrated under reduced pressure to a total volume of 66 mL, and 265 mL of methanol was gradually added while stirring at room temperature. After further stirring at room temperature for 8 hours, the precipitated crystals were collected by filtration and washed with methanol. The obtained crystals were dried under reduced pressure at 20 ° C. overnight to obtain 24.5 g (yield: 92.5%) of L-lysine · 1Ζ2 citrate crystals as pale yellow needles. Crystal composition analysis: shown in Table 3.

[0025] [Table 3] Table 3

Actual value (%). '■ Calculated value (%)

: L-Lysine 60.6 βΟΑChenic acid (%) 39.4 39-6

<¾) ': Each measured information is based on ¾-speed liquid chromatography (HPLC), L-Linidine is OPA coloring method (excitation wave! :: 340n, fluorescence wave! :: 455n mX Analysis and calculation by the method (detection wavelength: 210 nm).

One ':. Each calculated _{_{value, (C s H 3 N s}} O s> s · C s H s O T was calculated as in Example 3

[0026] By adding 10.5 g of citric acid (0.5 equivalent to L-lysine) to an L-lysine aqueous solution (containing 0.109 mol of L-lysine) obtained in the same manner as in Example 1, The pH of the aqueous solution was adjusted to 4.9. The resulting aqueous solution was concentrated under reduced pressure to a total volume of 38 mL. The obtained aqueous solution was dropped into 88 mL of ethanol while stirring at room temperature. The precipitated crystals were collected by filtration, washed with ethanol, and dried under reduced pressure at 20 ° C overnight to obtain 24.3 g (yield: 91.7%) of L-lysine 1Ζ2 citrate crystals as a pale yellow color. Obtained as needles.

,

Crystal composition analysis: shown in Table 4.

[0027] [Table 4] Table 4

Actual leakage (%)

L-Lysine (%) 60.4 Cenoic acid (%) 39.5 39.6

(Ά) ": Each measurement was performed using a ¾-speed liquid chromatography matrix <HPLC>, and L-lysine was subjected to OPA coloring (excitation coverage! :: 340 nm, ¾ light coverage :: 455 nm), Quen 醆 was analyzed by UV detection method (detection wavelength: 210 nm)!

"-: Each calculated value was calculated as <C s H i, N ₂ O _s ) _s · C ₆ H _s O _τ . Example 4

By adding 10.5 g of citrate (0.5 equivalent to L-lysine) to the L-lysine aqueous solution (containing 0.109 mol of L-lysine) obtained in the same manner as in Example 1, the pH of the aqueous solution Was adjusted to 4.9. The resulting aqueous solution was concentrated under reduced pressure to a total volume of 66 mL. The obtained aqueous solution was dropped into 265 mL of methanol while stirring at room temperature. The precipitated crystals were collected by filtration and methanol After washing with vacuum and drying under reduced pressure at 20 ° C. overnight, 24.9 g (yield: 94.0%) of L-lysine · 1-2 citrate crystals were obtained as pale yellow needles.

Crystal composition analysis: shown in Table 2.

[0029] [Table 5]

Table 5

Actual leakage (%)-Calculated value (%) Lysine (%) 60.6 60 4

Quenic acid (%) 39.4 39 6

(Ά)-: For each measurement, ¾-speed liquid chromatogram-i (HPLC) was used, and for L-lysine, OPA coloring method (excitation wavelength: 3400 nm, fluorescence wavelength: 45 5 nm) Was analyzed and detected by the UV detection method (detection wave !:: 2 10 nm).

...: Each calculation 1 'straight is (C _s HNO-> ₂ ' C _s H _s O _τ !: issued. Example 5

[0030] 900 g of L-lysine hydrochloride (720 g as L lysine) was dissolved in 18 L of water and passed through a column packed with 9 L of strongly acidic ion-exchanged resin (Marathon C) (H type). After washing the resin with 9 L of water, L-lysine was eluted with 18 L of 2 mol ZL aqueous ammonia. Concentrate the eluate under reduced pressure to about 5 L, and then add 474 g of cenoic acid (0.5 equivalent to L-lysine) to the resulting L-lysine aqueous solution (containing 4.93 mol of L-lysine). Was adjusted to pH 4.9. The obtained aqueous solution was decolorized by adding 60 g of activated carbon and treating at 50 ° C. for 30 minutes. Activated carbon was filtered off, and the filtrate was concentrated under reduced pressure to make the total volume 2.5 L. While stirring the obtained aqueous solution at 40 ° C., 2.5 L of ethanol was added, 20 g of seed crystals were inoculated, and the mixture was stirred at 40 ° C. for 5 hours. Next, 3.3 L of ethanol was added, the reaction solution was cooled to 20 ° C., and the precipitated crystals were separated by a centrifuge. The obtained crystals were washed with 1.2 L of ethanol, dried under reduced pressure at 30 ° C for 12 hours, and then dried under reduced pressure at 60 ° C overnight to obtain 1130 g of L-lysine Ratio: 94.7%) was obtained as white needles.

Crystal composition analysis: shown in Table 6.

[0031] [Table 6] Table 6

Actual (%) ':' Total <%) "

L-Lysine (%) C.2 6C .4

Chenic acid (%), ^ 9 s ί 0 g

(Note) ': Each measured temperature is ¾-speed liquid chromatography (HPLC) .. L-Rin is は Ρ Α Coloring method (Excitation wavelength: 340 nm, Fluorescence wavelength: 455 nm X Quin ^ is UV detection method ( (Detection wavelength: 21 C'nm).

…: Total! : The value was calculated as (C _E H _{t ¾} N _s O _s > ₂ ■ C _s H _s O _τ . Industrial Applicability

The crystals of L-lysine 'citrate provided by the present invention and the production method thereof are useful as a source of L-lysine.

Claims

The scope of the claims

[I] L—Lysine and succinic acid salt crystals.

2. The crystal according to claim 1, wherein the 5% by weight aqueous solution of the crystal has a pH of 3-6.

[3] The crystal according to claim 1, wherein the composition ratio of L-lysine and citrate is 2: 1 (molar ratio).

[4] The method for producing a crystal according to any one of [1] to [3], wherein L-lysine and citrate are dissolved in water, and the crystal is precipitated from the obtained aqueous solution.

5. The production method according to claim 4, wherein the pH of the aqueous solution is 3-6.

6. The production method according to claim 4, wherein the pH of the aqueous solution is 4.5 to 5.5.

7. The production method according to any one of claims 4 to 6, wherein the method for precipitating the crystal is a method comprising a step of adding a hydrophilic organic solvent to the aqueous solution.

[8] The production method according to any one of claims 4 to 6, wherein the method for precipitating crystals is a method comprising a step of adding an aqueous solution to a hydrophilic organic solvent.

[9] The process according to claim 7 or 8, wherein the hydrophilic organic solvent is an alcohol organic solvent, an amide solvent, acetone or acetonitrile.

[10] Whether the hydrophilic organic solvent is methanol, ethanol, propanol, isopropyl alcohol, butanol, ethylene glycol, diethylene glycol, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, acetone, or acetonitrile The production method according to claim 7 or 8, wherein the solvent is a solvent selected.

[II] The method according to claim 7 or 8, wherein the organic solvent power is ethanol or ethanol.