JPS598391B2 - Natural essential oil manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to remove the causative substances from natural essential oils containing psoralen compounds, which cause harmful effects on the skin, by eliminating the aroma of natural essential oils, such as the occurrence of operational troubles and side reactions. tone,
The present invention relates to a method for producing natural essential oils, which can be advantageously removed by industrially easy means without the risk of adversely affecting component balance, yield, etc., and which can produce natural essential oils of excellent quality that substantially do not contain psoralens.

Natural essential oils are widely used as fragrances for various cosmetics, such as creams, lotions, lotions, and other basic cosmetics, lipsticks, white powders, and other cosmetics, pomades, hair creams, hair tonics, and other hair styling products. ing.

However, psoralen compounds with coumarin cores contained in natural essential oils are known to exhibit phototoxic effects and cause, for example, dermatitis. , FITZPATRI
CK; Sunlight and Man (Univers
ityofTOKYOPress.

(1974), the cause of such phototoxic effects is due to compounds with a coumarin nucleus contained in natural essential oils, and among these compounds, for example, the following formula, Solaren sada ρ゜sada η.

4 ・ 4'-dimethyl 4 ・ 5'-dimethylpsoralen Psoralen ratio σ□ 4 ・ 8'-dimethyl 4 ・ 5' ・ 8-tripsoralen Methylpsoralen d 1 mm q.

It has been pointed out that psoralens such as 8-methoxyfluor 5-methoxypsoralen laren are the causative substances.

Conventionally, as a proposal for removing compounds with such coumarin cores from natural essential oils, bergamot essential oil, which is a type of natural essential oil, was distilled under reduced pressure at a temperature that did not change the components of bergamot oil to obtain distilled essential oil. On the other hand, the distillation residue was hydrolyzed with an alcoholic alkali in the cold to remove furocoumarins (psoralens) by converting them into the form of alkali salts of the hydrolyzate, and the remaining neutral oil was removed by the above-mentioned distillation. A proposal was made to produce bergamot essential oil, which does not irritate the skin, by combining it with essential oils (Special Publication No. 35-1).
No. 5363).

In this proposal, as described above, a chemical modification means is utilized in which psoralen is converted into an alkali salt form of its hydrolyzate using an alcoholic alkali and removed.

However, the alkali salt formed becomes a saponified product (emulsification), and separation of this from the neutral oil is operationally extremely difficult and requires a considerable amount of time, such as saponification overnight at room temperature with stirring. Due to contact with alkali over a long period of time, useful neutral oil components other than psoralen may be oxidized.
The main reason is that it is difficult to avoid side reactions such as polymerization and isomerization, which leads to deterioration in the aroma, color tone, and component balance of the obtained natural essential oil, which is accompanied by inconveniences such as coloring and aroma deterioration. In addition, there are many technical deficiencies, such as a decrease in purity and yield, and the unavoidable contamination of psoralen compounds in essential oils in non-negligible amounts. The present inventors conducted research to solve the above-mentioned dissatisfaction and to develop a method for producing natural essential oils that do not contain psoralen compounds on an industrial scale.

As a result, by combining the method of distilling psoralen-containing natural essential oils under reduced pressure conditions with the physical means of crystallizing and removing psoralen compounds using a nonpolar solvent from the distillation residue, it was possible to solve the above-mentioned conventional proposal. Many technical deficiencies have been resolved at once, and natural essential oils containing psoralen compounds can be converted into natural essential oils that do not substantially contain the harmful substances psoralen compounds, with a good aroma, color tone, well-balanced components, good purity, and good yields.
It was found that it can be manufactured with easy operation, good quality reproducibility, industrial advantage, and low cost. Therefore, an object of the present invention is to provide an industrially advantageous process for producing an excellent quality natural essential oil substantially free of psoralen compounds from a psoralen compound-containing natural essential oil.

Further objects and advantages of the present invention will become more apparent from the following description.

Examples of psoralen-containing natural essential oils used in the method of the present invention include bergamot oil, lemon oil, orange oil, grapefruit oil, petitgrain oil, lime oil, mazdarin oil, verbena oil, and angelica oil.

According to the method of the present invention, a natural essential oil containing psoralen compounds is distilled under reduced pressure conditions to obtain a distilled essential oil substantially free of psoralen compounds, while the distillation residue is cooled in the presence of a nonpolar solvent. The psoralen compounds in the residue are crystallized and removed, and the nonpolar solvent is removed from the residual liquid, and the obtained essential oil is combined with the distilled essential oil.

Distillation under the reduced pressure conditions described above can be carried out by appropriately selecting the degree of reduced pressure and temperature so as to obtain a natural essential oil that does not substantially contain psoralen compounds without altering the natural essential oil.

In general, conditions can be adopted that do not impair the aroma of essential oil components such as terpene hydrocarbons, terpene alcohols, terpene aldehydes, and esters contained in natural essential oils, such as a temperature of about 100°C or less, and a degree of reduced pressure. Approximately 5mmHg
The following conditions are often adopted: In general, it is preferable to select the lower of both the temperature and the degree of vacuum. In addition, the amount of distillation obtained by distillation is variously selected depending on the content of psoralen in the psoralen-containing natural essential oil, but generally,
The distillation amount is about 95% by weight based on the natural essential oil used. It is best to distill as much as possible without sacrificing the aroma. In the present invention, while the distilled essential oil is collected as described above, the distillation residue is cooled in the presence of a nonpolar solvent to crystallize and remove psoralen compounds in the residue.

As the nonpolar solvent used to crystallize the psoralen in the distillation residue, for example, hydrocarbons such as butane, pentane, isopentane, hexane, heptane, octane, and cyclohexane can be preferably used, but
Particularly preferred solvents are pentane, isopentane, hexane, heptane and the like.

The amount of the non-polar solvent to be used is, for example, about 1 to about 5 times the weight of the distillation residue, but preferably about 1 times the weight.

Further, the temperature during crystallization can generally be about 10°C or less, preferably about 0°C or less. The crystallization time is not particularly limited, but it is sufficient to leave it overnight under the low temperature conditions as exemplified above. The residual liquid after removing the psoralen crystallized as described above, that is, the non-polar solvent-containing essential oil component, is combined with the distilled essential oil after removing the solvent to form a natural oil containing substantially no psoralen compounds. Essential oils can be produced with good purity and yield, advantageously in terms of operation and quality reproducibility, and at low cost. Thus, according to the method of the present invention, only psoralens are removed, and a well-balanced and aromatic natural essential oil is obtained with no change in other useful essential oil components, and the analysis results of this by high performance liquid chromatography are as follows: It is possible to provide a high-quality natural essential oil that has no psoralen peak and does not cause dermatitis and has high utility value.

Hereinafter, several embodiments of the method of the present invention will be explained in more detail by way of examples and comparative examples.

Example 1 400t of bergamot oil at reduced pressure of 21nLH
Distill the fraction from the boiling point to 76°C under the conditions of g,
A colorless distilled essential oil 374y is obtained.

Paste-like dark green distillation residue 257 and n-hexane 2
After adding 5y and uniformly dissolving the mixture, it is left to stand overnight at a temperature of -5°C to 1°C to crystallize the psoralen. The crystal part is f
Separation gives 17t of off-white crystals. In the solution part, n-hexane was distilled off, and bergamot oil 38 was added to the distilled essential oil.
Get 07. As a result of high performance liquid chromatography analysis of the obtained bergamot oil with a yield of 95% relative to crude oil, no psoralen peak was observed. Example 2 1.5 kg of orange oil was reduced to 3W! Under MHg conditions,
The distilled fraction with a boiling point of up to 94°C is distilled to produce a colorless essential oil of 1.39k8! get.

Paste-like yellow distillation residue 90V and n-heptane 90V
After adding y and uniformly dissolving the mixture, it is left to stand overnight at a temperature of -5 to -10°C to crystallize the psoralen. The crystal part is separated to obtain pale yellow crystal 20y. In the solution part, n-heptane is distilled off, and the mixture is combined with the pre-distilled essential oil to obtain 1.46 kg of orange oil. Yield based on crude oil: 97.3%. As a result of high performance liquid chromatography analysis of the obtained orange oil, no peak of psoralen was observed.

Example 3 Lemon oil 1.51<9 was distilled under conditions of reduced pressure of 3 mmHg and the fraction from the boiling point to 94°C was distilled to obtain a colorless distilled essential oil 1.
．． Get 4157.

Paste-like reddish brown distillation residue 797 and n-pentane 7
After adding 97 and uniformly dissolving it, the mixture was left to stand overnight at a temperature of 1 to 5°C to crystallize the psoralen. Separate the crystal part ▲ to obtain pale yellow crystal 147. The solution part distills n-pentane and combines it with the pre-distilled essential oil to obtain 1.479k9 of lemon oil.
As a result of high performance liquid chromatography analysis of the obtained orange oil, no peak of psoralen was observed.

Example 4 The same procedure as in Example 1 was carried out except that the amount of n-hexane used in Example 1 was changed to 270y to obtain 25y of colorless crystals and a total of 1375V of bergamot oil.

As a result of high performance liquid chromatography analysis of the obtained bergamot oil with a yield of 93.8% relative to crude oil, no psoralen peak was observed. Example 5 The same procedure as in Example 2 was carried out except that the amount of n-heptane used in Example 2 was changed to 270 V, and 217 pale yellow crystals were obtained, giving a total of 1.45 k9 of orange oil.

As a result of high performance liquid chromatography analysis of the obtained orange oil with a yield of 96.7% relative to crude oil, no peak of psoralen was observed.

Comparative Example 1 According to the example of the above-mentioned Japanese Patent Publication No. 35-15363, psoralen-containing bergamot oil was distilled under reduced pressure to obtain distilled essential oil, and the distillation residue was distilled with 5% caustic potassium according to the example. The alkali salts formed by cold hydrolysis using a methanol solution were removed, and the mixture was combined with the distilled essential oil to obtain bergamot oil.

Furthermore, a sensory test was conducted regarding the slope of the bergamot oil obtained in Example 1 (invention) and the bergamot oil obtained in the comparative example.

The test was performed in triplicate on each sample by 10 expert examiners. The results of the sensory test were as shown in the table below. As shown in the table above, out of the 10 inspectors, with one exception, all the remaining 9 inspectors judged that the slope of the sample of Example 1 was smooth.

Claims (1)

[Claims] 1. Distilling a natural essential oil containing psoralen compounds under reduced pressure conditions to collect a distilled essential oil that does not substantially contain psoralen compounds,
On the other hand, the distillation residue is cooled in the presence of a nonpolar solvent to crystallize and remove psoralen compounds in the residue, and the essential oil obtained by removing the nonpolar solvent from the residual liquid is added to the distilled essential oil. A method for producing a natural essential oil substantially free of psoralen.