JP2002047239A - Method for isolating/purifying nootkatone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily and highly selectively collecting nootkatone existing in a mixture by combining an operation such as distillation or extraction with a collecting operation using a clathrate compound. SOLUTION: This method is characterized by comprising the following process: a mixture containing nootkatone previously fractionated by an operation such as distillation or extraction is contacted with a cyclic compound having an including ability such as a cyclodextrin to selectively form a nootkatone- included complex, from which the nootkatone is eliminated and collected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for separating and purifying nootkatone.

[0002]

BACKGROUND OF THE INVENTION Natural essential oils are known to be mixtures of a very wide variety of compounds. Among them, many high value-added compounds having various functions are included.
Nootkatone which is a sesquiterpene compound is one of them, but a method of separating and purifying this compound from essential oils is as follows.
Usually, the distillation and extraction operations are performed in combination with high performance liquid chromatography or column chromatography.

In the distillation operation, precision distillation is generally performed in order to separate mixed compounds having very close boiling points, but it is difficult to sufficiently increase the purity of the target product.

[0004] In order to further separate the target compound from the fraction obtained once, a method of recovering a high-purity compound by using a high-performance liquid chromatograph or a column chromatograph has been performed. However, chromatographic operation is not suitable for component separation in industrial applications from the viewpoint of cost and equipment.

[0005] In addition, as a method for extracting and recovering an active ingredient from essential oil with high selectivity using cyclodextrin, tree essential oil is used as a raw material, and anti-mite,
A method for obtaining a terpene compound fraction having a strong antibacterial action has been proposed. (JP-A-07-268384)

However, in this method, since the obtained fraction is obtained in a state of being mixed with a compound other than the target compound, the purity of a specific compound is increased only up to about 30 to 45% by weight. However, the purity of the resulting compound cannot be sufficiently increased.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve such problems in the prior art and to combine distillation, extraction and the like with a recovery operation using an inclusion compound.
An object of the present invention is to provide a method for simply and highly selectively recovering nootkatone present in a mixture.

[0008]

According to the present invention, a nootkatone is prepared by contacting a mixture containing a nootkatone, which has been fractionated in advance by an operation such as distillation or extraction, with a cyclic compound having an inclusion ability such as cyclodextrin. Is selectively formed. Then, the nootkatone is desorbed and recovered from the clathrate complex. Further, the cyclic compound to be used is at least one of cyclodextrin, branched cyclodextrin, and chemically modified cyclodextrin, or a separation and purification method using calix arene or chemically modified calix arene. Further, it is preferable that the fraction obtained by this operation is a separation / purification method in which the nootkatone purity of the fraction is 60% by weight or more.

The mixture containing nootkatone as a raw material includes, but is not limited to, a fraction obtained by distillation, extraction or the like from a citrus essential oil. Preferably, a citrus essential oil fraction such as an orange essential oil fraction is used. Nootkatone purity in these mixtures is not particularly limited, and is usually in the range of 1 to 25% by weight (gas chromatographic purity,% by weight).

The recovery of the active ingredient is performed, for example, by the following operation. A mixture containing nootkatone is added to the aqueous solution of cyclodextrin, and the mixture is brought into contact with stirring to form a cyclodextrin clathrate of the active ingredient. The contact is usually carried out by dissolving cyclodextrin in water, adding the mixture to the mixture, and vigorously stirring or shaking with a stirrer for several seconds to several hours. Inclusion by sonication is also possible. But,
It is not limited to these methods. The mixture containing nootkatone can be added as it is or dissolved in a suitable organic solvent.

After the completion of the contact reaction, oil-water separation is performed.
The lower layer aqueous solution of cyclodextrin containing the nootkatone clathrate is separated from the upper layer essential oil fraction. The separation method is performed by a general method. By this operation, the rectified fraction not included in the clathrate compound and the nootkatone clathrate can be separated.

By extracting the aqueous solution with a solvent such as diethyl ether, the nootkatone contained in the hollow portion of the cyclodextrin cyclic structure is extracted and recovered on the solvent side.
Nootkatone during mixing can be obtained selectively.

The clathrate compound used in the above has a cyclic structure, and the hollow portion of this cyclic compound is characterized in that it has a clathrate ability. Examples of these include cyclodextrin, calixarene and the like.

Examples of the cyclodextrin include α-cyclodextrin having 6 units of glucose, β-cyclodextrin having 7 units of glucose, γ-cyclodextrin having 8 units of glucose, and δ- and ε-cyclodextrin having a high degree of polymerization. Further, any of these may be used, such as a branched cyclodextrin that has been branched to improve solubility in water, a chemically modified cyclodextrin having a substituent added thereto, and the like. Preferably, chemically modified cyclodextrin is used.

The calixarene is a calix [4] arene in which a phenol unit is linked by a 4 unit methylene group, a calix [6] arene in which a phenol unit is linked by a 6 unit methylene group, and a phenol unit is linked by an 8 unit methylene group. Any of these may be used, such as calix [8] arene, and derivatives thereof.

The concentration of the aqueous clathrate compound used is usually 0.1 to 50% by weight (W / W,% by weight), preferably 1 to 50% by weight.
-30% by weight (W / W,% by weight). Conditions outside these ranges are not preferred because the operability during oil / water separation deteriorates. The amount of the host compound added is
Usually 1 mole to 5 times the target compound contained in the raw material
It is in the range of 0 mole, preferably 1 mole to 10 mole. The contact reaction temperature is usually from 0 to 60C, and preferable conditions are from 5 to 35C. Conditions outside these ranges are not preferred because the recovery rate decreases.

The solvent for extracting the active ingredient from the aqueous solution of the clathrate may be any of a polar organic solvent and a non-polar organic solvent which are not homogenized with water. Examples include, but are not limited to, diethyl ether, hexane, and the like.

The purity of the nootkatone fraction obtained in the above-mentioned operation is usually 60% by weight or more. Depending on the composition of the mixture containing the raw material nootkatone, 60-
High purity nootkatone with a purity of 80% by weight can be recovered. The recovery rate of nootkatone by this operation is usually 50% by weight or more.

Since the clathrate used is not decomposed in the above-mentioned operation process, it can be recovered and reused.

[0020]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The cyclodextrin (hereinafter sometimes referred to as CD) and calixarene used in the examples are as follows. HP-β-CD: hydroxypropyl-β-cyclodextrin: Calix [6] arene SO ₃ Na: sodium p-sulfonate-calix [6] arene: manufactured by Sugai Chemical Industry Co., Ltd.

Example 1 (Selective recovery of nootkatone using chemically modified cyclodextrin) 89.3 g of HP-β-CD (manufactured by Shiosui Minato Sugar Co., Ltd)
(61.6 mmol) in 205.4 ml of water,
An aqueous cyclodextrin solution was prepared. To this, 10.0 g of an orange essential oil fraction containing 15.6% by weight of nootkatone as a target compound in gas chromatographic purity obtained by distilling the orange essential oil was added. The mixture was stirred at 25 ° C. for about 30 minutes to form a nootkatone clathrate. The orange essential oil fraction which was left to stand and was not included was separated into a cyclodextrin aqueous solution and a cyclodextrin aqueous solution fraction in which nootkatone was included in the hollow portion of the CD was obtained.
The obtained aqueous solution was extracted with diethyl ether, and the solvent was removed by a distillation operation to obtain 1.85 g of an oil fraction. The fraction was analyzed by gas chromatography, and found to have a nootkatone purity of 79.8% by weight. The recovery of the target compound was calculated by the following formula. Target compound recovery (%) = (weight of target compound in recovered oil fraction / weight of target compound in raw material) × 100 The calculated nootkatone recovery was about 80% by weight. (Gas chromatograph measuring device) Apparatus: Hewlett
HP6890GC SYSTE manufactured by Packard
M column: HP-5 (Length 30m, Colu
mn ID 0.32mm)

Example 2 (Selective recovery of nootkatone using chemically modified calixarene) Calix [6] arene SO ₃ Na (manufactured by Sugai Chemical Industry Co., Ltd.) 76.9 g (61.5 mmol) was added to water 19
Dissolve in 3.74 ml and calix [6] arene S
An O ₃ Na aqueous solution was prepared. To this, 10.0 g of an orange essential oil fraction containing 15.6% by weight of nootkatone as a target compound in gas chromatographic purity obtained by distilling the orange essential oil was added. The mixture was stirred at 25 ° C. for about 30 minutes to form a nootkatone clathrate. Separated settled and separated into the orange essential oil fraction which has not been clathrate calix [6] and arene SO 3 _Na aqueous solution to obtain a calix [6] arene SO 3 _Na aqueous fraction was inclusion nootkatone . The obtained aqueous solution was extracted with hexane and the solvent was removed by a distillation operation to obtain 1.35 g of an oil fraction. When this fraction was subjected to gas chromatography, the nootkatone purity was 66.2% by weight. The recovery of the target compound was calculated in the same manner as in Example 1 above. The calculated nootkatone recovery was about 63% by weight.

[0023]

According to the recovery method of the present invention, nootkatone, which is an active compound present in an essential oil fraction, is distilled,
By combining the extraction operation and the recovery operation using the inclusion compound, it is possible to obtain easily and highly selectively. In addition, this method has good recovery efficiency and can recover nootkaton at lower cost.

Claims (4)

[Claims] 1. A method comprising selectively contacting a mixture containing nootkatone with a cyclic compound having an inclusion ability to form an inclusion complex of nootkatone and then removing the nootkatone from the inclusion complex. A method for separating and purifying nootkatone. 2. The nootkatone according to claim 1, wherein the cyclic compound is at least one of cyclodextrin, branched cyclodextrin which is branched to improve solubility in water, and chemically modified cyclodextrin to which a substituent is added. Separation and purification method. 3. The cyclic compound has a phenolic unit having 3 to 8 phenol units.
The method for separating and purifying nootkatone according to claim 1, wherein the unit is a calixarene and / or a derivative thereof bonded by a methylene group in units. 4. The method for separating and purifying nootkatone according to claim 1, wherein the purity of the nootkatone obtained is 60% by weight or more.