JPS6143143A - Glycerin ester of eicosapentaenoic acid and its preparation - Google Patents

Abstract

NEW MATERIAL:A compound shown by the formula I (R is eicosapentaenoyl, acyl of high fatty acid except eicosapentaenoic acid, or 2-4C lower aliphatic acyl; with the proviso that a case where at least one of R is eicosapentaenoyl, and all the remaining R are not acyl except acyl of eicosapentaenoic acid). EXAMPLE:1,2,3-Trieicosapentaenoylglycerin. USE:A drug or an auxiliary food for nutrition. PREPARATION:A glycerin ester of 2-4C lower fatty acid such as preferably triacetin (triglyceride of diacetate), etc. shown by the formula II (R'-R''' are acyl of 2-4C lower fatty acid) and an eicosapentaenoic acid lower alkyl ester such as a higher fatty acid ester mixture containing >=30wt% eicosapentaenoic acid lower alkyl ester are subjected to ester exchange in the presence of an alkali metal alcoholate, etc. in an inert gas atmosphere preferably N2, etc. to give a compound shown by the formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a glycerin ester of eicosanic acid (hereinafter abbreviated as BPA) and a method for producing the same.

BPA exists in large amounts in nature as one of the fatty acids in fish oil. Polyunsaturated fatty acids such as EPA have long attracted attention from a nutritional perspective, and J. Dyerberg, in particular, reported that they are effective in preventing adult diseases (The Lancot,
Since July 15, 117 (1978), research on it has become active, and it is known that it plays an important role in supporting life as a starting material for prostaglasin.
Its application to pharmaceuticals and nutritional supplements is expanding.

Therefore, an object of the present invention is to provide a glyceride of RlFA that can be advantageously used as a pharmaceutical product or a nutritional supplement, and a method for producing the same.

[Prior art]

As mentioned above, KPA exists in nature as a fatty acid component of fish oil, etc., but the EPA content in various fish oils is 16'>1. Sardine oil 15.81, walleye cod liver oil 12.6%, squid oil IQ 2%, mackerel oil A11, saury oil 4.91! , shark liver oil is about 5-6 degrees (Oil Chemical Gas Chronodata 1978-1980).

1 from these oils! ! As a method for separating and purifying triglycerides bound to Ph, low-temperature crystallization (JP-A-59-5
9644, 59-672-41), but the BPA content is up to about 25'1, and chromatography,
Solvent extraction and molecular distillation methods are also known, and Teilka and KPA are 2
Since almost no molecularly bound glyceride exists in nature, the EiPA content of about 301 is the limit depending on the concentration method.

On the other hand, the lower alkyl estermo of upum is well known,
Since PA has a high degree of unsaturation, it is difficult to increase its content, and in practice only about 30% of 601 can be obtained at most. Moreover, it is said that glycerin esters, especially monoglycerides, are advantageous for the digestion and absorption of EPA.Therefore, there is a demand for glycerin esters of BPA with a high content of FPA.
Glycerides in which only PA is bound have not yet been known.

[Problem to be solved by the invention]

As is already known, when fish oil is exposed to air, it undergoes auto-oxidation, resulting in a decrease in nutritional value and a deterioration in flavor. This is also the case with EPA-containing fats and oils obtained by concentrating fish oil, etc., and this deterioration phenomenon progresses due to free radical chain reaction, resulting in the accumulation of hydroxyl oxide in the fats and oils, and the decomposition products are toxic and spoilage. Its use is limited because it causes

[Means for solving problems]

Therefore, by reducing impurities other than fats and oils as much as possible, IIIPA
By obtaining a glycerin ester with a high content of EiPA, preferably with only EPA bound, it is possible to reduce the amount of a small amount of EiPA glycerin ester used in applications where a desired constant amount of KPA is required. Based on the idea that the loss of flavor and deterioration of flavor seen in fish oil or fish oil concentrate can be reduced, we have discovered a method for producing glycerin esters containing high concentrations of EPA, especially only EPA.
The invention has been completed.

Therefore, the present invention relates to the formula (wherein R is the same or different, eicosa represents an antaenoyl group, an acyl group of a higher fatty acid other than eicosa citric acid, or an acyl group of a C2 to C4 lower fatty acid,
However, at least one R represents an eicosa-ntaenoyl group, and all of the remaining R are not acyl groups of higher fatty acids other than eicosapentaenoic acid. This invention relates to glycerin ester of PA and its production method.

Glycerin ester of BPA of the above formula of the present invention (in the formula R
', R'' and R'' represent an acyl group of a C2-C4 lower fatty acid.

The lower alkyl ester of EPA used in the present invention is preferably of high purity; however, as mentioned above, the lower alkyl ester of ICPA is also unstable and easily deteriorates, so it is difficult to commercially obtain a lower alkyl ester of ICPA. Therefore, in the present invention, depending on the use of the BPA glycerin ester product, products with a relatively low content of IPA lower alkyl esters, such as crude lower alkyl esters containing 30 or more BPA lower alkyl esters, may also be used. can.

As the glycerin ester of formula (2), which is one of the raw materials, triacetin (triglyceride of acetic acid) is preferable. When triacetin is used, the lower ester produced as a by-product is a low boiling point component such as methyl acetate, so it can be easily separated from the glycerin ester of formula (1) and is inexpensive. Furthermore, unreacted lower alkyl ester of KPA remains in the product of the present invention.
Since the lower alkyl ester of IPA itself is not a harmful substance, it is not necessarily necessary to completely remove it. However, in view of the purpose of the present invention, it is necessary that the crude product contains 30 or more l1iPA as a higher fatty acid component.

The method of the present invention and the method for producing the lower alkyl ester of EPA as a raw material will be explained in detail below.

To prepare citric acid ester, refined sardine oil is transesterified with a lower alcohol to obtain a fatty acid ester mixture. From the fatty acid ester mixture, saturated fatty acid esters are removed by urea inclusion, and the composition ratio of EPA is adjusted to 35 to 35.
After reaching 40%, distillation is repeated to obtain high purity I! ! Obtain ph ester.

Next, the desired eicosa R-ntaenoic acid glycerin ester is prepared in the presence of a nitrogen-containing strong organic base (such as diazabiscif tetraendecene), a strong basic resin (Amberlis A-260 Organo Co., Ltd.), an alkali metal alcoholade, etc.
For example, it is prepared by exchanging a triglyceride of a lower fatty acid, such as triacetylate, with a high purity eicosapentaenoic acid ester in the presence of sodium methylate (powder). 1 part triacetin and high purity eicosabontaeic acid ester
Add to the reactor at a ratio of 1 to 5 moles and add 1 to 5 moles based on the amount of starting materials.
Add 5 portions of sodium methylate, and proceed with the reaction under heating, stirring, and reduced pressure. Since lower fatty acid ester is generated as the temperature of the reaction solution increases, it is preferable to remove it from the reaction system by reducing pressure. Reaction temperature is 60-200℃
, preferably 80 to 100°C, and a reaction time of 1 hour is sufficient. When the formation of lower fatty acid esters is no longer observed, water is added to stop the reaction. To prevent oxidation of IPA, reactions and operations are preferably carried out in an inert gas atmosphere such as nitrogen.

Next, the reaction solution is neutralized with an acid if necessary, water and an organic solvent such as ethyl acetate are added if necessary and shaken, and the mixture is separated into two layers, after which the aqueous layer is removed.

The organic layer is further washed with water for 5 degrees, and then the organic layer is separated. If a solvent is used, the solvent is distilled off under reduced pressure to obtain a pale brown, transparent oil containing PA.

Further, the oily substance is fractionated by thin layer chromatography, silica gel column chromatography, etc. depending on the number of fatty acid groups substituted with K. Furthermore, separation based on the difference in boiling point is possible by molecular distillation. For example, silica gel column chromatography is carried out using ethyl acetate, acetone, etc. Collect each fraction while checking the eluate by thin-layer graphography.

Example 1 Transesterification of refined sardine oil and ethyl alcohol,
Then, the eicosa with a purity of 87% was purified and converted into ethyl ntaenoic acid ester with a purity of 10%. Of and sodium methylate) [12F was added to a 100-4-hole flask and the container was purged with nitrogen gas.

Slow stirring and heating were started, and 2.2 t of triacetin was injected from the dropping funnel, and the pressure was reduced using an aspirator.

As the temperature of the reaction solution increased, the produced ethyl acetate distilled out, and was condensed and removed using a cooler. Oil bath salt 80-1
00℃, 1 hour after the start of the reaction, remove the oil path from the reactor, cool the internal temperature to around room temperature, add acetic acid 21R1, then add ethyl acetate and water, shake, and leave to stand; two layers will separate. Separate the upper ethyl acetate layer and add 20ml of water.
After washing three times, the solvent was distilled off under reduced pressure to obtain &6f, a light brown, transparent oil.

Next, 50 t of silica gel (70-230 mesh, Merck #) was suspended in a glass tube of φ3 crn x 30 cIn.
Filled. To this was added 1 t of the above light brown oil, 200 m of hexane, hexane-ether (95: 5 v/v
) 1000 m, hexane-ether (85:15) 1
000m, Hexane-Ete# (70:30) 600
Stepwise elution was performed with - and acetone 200-.

The solvent was distilled off from the obtained eluate under reduced pressure, and in the order of elution, eicosa was 0.24 f of ntaenoic acid ethyl ester,
1,2.3-) Lieicosa is taenoylglycerin [1,57F, 2-acetyl-1,3-dieicosaintaenoylglycerin 0.1Of and 1-eicosapentaenoyl-2,5-diacetylglycerin [ L.O.
I got Il.

The infrared absorption spectra and nuclear magnetic resonance spectra of glycerol esters are as follows.

1.2.5-) Lieicosa is antaenoylglycerin 2925(s), 2850(s), 1470h))-C
H2-1760(s), 1155(s) ) -C
O-0-0,98 (9H, t, CH5-CH2-)1.
30 (6H, br, CH3-CH2-)1.70 (
6H, m, -CH2-CH2-CH2-)2.08 (
6H, m, CH2-CH2-CH=CH2.52
(8H, m, -C-CH2-Cchin (H-)Z82 (
24H,m, =CH-CH2-CH-)4.22 (
4H,m, CH20CO-MPA)5A,22 (
IH, m, CHOCO-BPA) & 36 (30H
, m, -C body CH-) 2-acetyl-1,3-jaycosine quenoylglycerin 1760 (θ+, 1155 (s)) -co-
o-0,98 (6H,t, c!3-co2-)1,5
0 (4H, br, CJ-Cfi2-)2.08 (
4H, m, CH2-C! (2-CH-CH2.32
(4H, m, <knee CH2-C 耽H-)2.82
(16H,m, -CH-CH2-C;)4,22 (
4H, m, CH20cO-EFA)5.22 (1H
, m, C! 0CO-CH5)5.56 (20H, m
, -cHMc)! -) 1-eicosapentaenoyl-
2,3-Diacetylglycerol R (scy+5-1): 2960(m), 287
06n) 1465←), 1580(m) 2925h), 2850(m) 147 oh) 1760(s) 1220(s) 1660611) 710(b) 'H-HMR(2GOM)Iz, CDC4, δ];
[L98 (3H,t, CH3-CH2-)1.30
(2H, br, CH2-CH2-)2.08 (2
H, m, C)12-CH2-CH-CH-)2.32
(2H, m, -C-CH2-CHl-CH-)2.
82 (8H, m, riH-(J(2-C)b)4.2
2 (4H, m, CH20CO-IPA) 5.22
(IH, m, CHOCO-CH5)5.56 (,1
0H, m, -C3Ej-) Example 2 90% eicosine citrate methyl ester 19.2F
,) lyacetin 4.4f and potassium ethyl) 0
．． Transesterification was carried out in the same manner as in Example 1 using 4f to obtain a light brown transparent oily substance 17. I got Of.

1.5f of the above oily substance was subjected to silica gel column chromatography, and stepwise elution was performed with hexane, hexane-ether and acetone in the same manner as in Example 1 to obtain 1,2.3-) Rieiko f d phthaenoyl. Glycerin 0.86f, 2-acetyl-1,3-diacetylglycerin 0.15t and 1-eicosa phtaenoyl-2,3-diacetylglycerin 0
．． I got 11F.

Example 3 87-nicosine citric acid ethyl ester obtained by transesterifying purified sardine oil with ethyl alcohol and then purifying it 10. Of and sodium methylate 0.2
100 m7! of 4 flasks were added, and the vessel was purged with nitrogen. Slow stirring and heating were started, and 2.2 t of triacetin was injected from the dropping funnel, and the pressure was reduced using an aspirator. As the temperature of the reaction solution increased, the produced ethyl acetate distilled out, and was condensed and removed using a cooler. Oil bath temperature is 80-100℃, 1 hour after the start of the reaction, remove the oil bath from the reactor, cool the internal temperature to around room temperature, add acetic acid 2-, then ethyl acetate and water, shake, and leave to stand. Two layers were separated, so the upper ethyl acetate layer was separated, washed three times with 200ml of water, and the solvent was distilled off under reduced pressure to obtain a6f, a light brown, transparent oil.

Next, 1 ton of the above oily substance was suspended in hexane with silica gel (70-230 mesh, Merck & Co., Ltd. 11) sat, and applied to a column packed in 30 x φ3eIR glass tubes. Hexane 200m, hexane-ether (95:5,
v/v) The fractions eluted at 1000- were collected, the solvent was distilled off under reduced pressure, and a pale yellow-transparent oil was obtained.
．． I got 24f. This material was separated by thin layer chromatography to reveal unreacted eicosine citrate ethyl ester. Furthermore, hexane-ether (8
5:15) 1000m/, hexane-ether (70:
30) The fractions eluted with 600- and acetone 200- were collected and the solvent was distilled off under reduced pressure, leaving a light brown, transparent oil with 0
．． I got 75f. This oil was transesterified with methanol to prepare fatty acid methyl ester.

Gas chromatography analysis was performed to investigate this fatty acid composition. Eicosine citric acid content is 86.7
It was excellent.

Condition column for gas chromatography (from F): 1
Q %DIIiG8 Chromoeorb WAN
DMC860/80 (manufactured by Gascro Industries Co., Ltd.) φ3
w+X2m glass Temperature: Injection chamber 240°C Oven 195°C Carrier gas: Nitrogen 50-7 minutes Holding time: Approximately 20 minutes Example 4 120 t of triacetin and 8% eicosa (537 g of citrate ethyl ester, sodium methyl) 10.
Transesterification was carried out in the same manner as in Example 3 using 8F, and post-treatment was carried out to obtain a light brown, transparent oil (i) 5229.

Next, 190f of the oil (i) was subjected to thin-film centrifugal molecular distillation, and 45.6f of the unreacted ethyl ester distilled out first was removed. An oil of Fl O1) was obtained. In order to confirm the fatty acid composition of this oil (ii), fatty acid methyl ester was prepared by transesterification with methanol, and gas chromatography analysis was performed in the same manner as in Example 3. As a result, the eicosine taenoic acid content was 49
．． It was 0%.

Example 5 Triacetin 2.2f, 52.0@Eicosa ntaenoic acid methyl ester 10. Of, sodium methylate 0
．． Transesterification was carried out in the same manner as in Example 3 using No. 29 to obtain a pale brown, transparent oil (i) a 4t. This was subjected to silica gel column chromatography (hexane-ether-acetone system) to remove unreacted methyl ester to obtain an oily substance (ii). As a result, the citric acid content of Eicosa was 33%.

Example 6 Higher fatty acid methyl ester 7 containing 50% by weight of triacetin 18f and eicosine citrate methyl ester
2f and 1.42 of sodium methisheet were charged into a fourth 200- flask. While stirring (700
RPM) 80-9 DC for 30 minutes.

After the reaction was completed, the reaction solution was washed with water, and then activated clay 27F was added and stirred for 1 hour. Activated clay is removed from the furnace and oil is heated to 85F.
I got it. This was molecularly distilled and acetin fat 51f (
130°C to 180°C 10.002 Torr) and triglyceride 148f (185°C to 200°C/(LOO
2 Torr) was obtained. In order to investigate the fatty acid composition of this triglyceride, the same operation as in Example 3 was performed and gas chromatography analysis was performed. The eicosapentaenoic acid content was 50-.

Example 7 26t of triacetin, 64f of higher fatty acid ethyl ester containing 50% by weight of ethyl ester of ntaenoic acid, and 200% of sodium methylate
I put four of them into a flask. Thereafter, the same operation as in Example 6 was performed to obtain acetin fat 21.4F(1) and triglyceride (El) 3&Ot.

As a result of gas chromatography analysis, (Summer) and (I
The content of eicosine citric acid contained in I) is both 5O
It was ts.

Example 8 Triacetin 42t1 Eicosa is higher fatty acid methyl ester 4 containing 90% by weight of ntaenoic acid ethyl ester
8f and sodium meth? -) 1.6f was charged into four 200m round flasks. The same operation as in Example 6 was carried out to obtain acetin 7at (1162,79) and triglyceride 6.9f. As a result of gas chromatography analysis, it was found that (1) and eicosintaenoic acid contained in (1) The content was 9096 in both cases.

Claims (1)

[Claims] 1) Formulas ▲ Numerical formulas, chemical formulas, tables, etc. A glycerin ester of eicosapentaenoic acid, which represents an acyl group of a lower fatty acid, provided that at least one R represents an eicosapentaenoyl group, and all of the remaining R's are not acyl groups other than eicosapentaenoic acid. 2) Formulas characterized by transesterifying glycerin esters of lower fatty acids C_2 to C_4 with eicosapentaenoic acid lower alkyl esters ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formulas, R is the same or different; It represents a pentaenoyl group, an acyl group of a higher fatty acid other than eicosapentaenoic acid, or an acyl group of a C_2 to C_4 lower fatty acid, provided that at least one R represents an eicosapentaenoyl group, and all of the remaining R 3) A higher fatty acid ester mixture containing 30% or more of eicosapentaenoic acid lower alkyl ester is used as the eicosapentaenoic acid lower alkyl ester. The manufacturing method according to claim 2.