JPS6321719B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a method for producing lemon oil that does not have phototoxicity, and more specifically, after distilling lemon oil under reduced pressure at a temperature and pressure that does not change its components, the residue is non-polar. After adding a solvent to precipitate and remove furocoumarins, and removing remaining furocoumarins by adsorbing them to an inorganic adsorbent, the oil obtained by removing the solvent is combined with the distillate oil to produce the oil. This invention relates to a method for producing lemon oil that does not have characteristic phototoxicity. Lemon oil is a natural essential oil that is essential as a cosmetic fragrance and is used in large amounts in perfumes, colognes, etc. However, lemon oil contains components that have phototoxic effects that cause skin irritation when exposed to sunlight. When used as a fragrance ingredient in products that are applied directly to the skin, such as perfumes and creams, it is necessary to remove harmful substances. Conventionally, the causative agent of phototoxicity in lemon oil is said to be furocoumarins, as in bergamot oil. Ten types of furocoumarins, such as bergapten and bergamotutin, are known to exist in lemon oil (AIGray, PGWaterman;
Phytochemistry Vol. 17, P. 845-864, 1978).
However, bergapten is said to have the strongest phototoxicity among furocoumarins, but the bergapten content in lemon oil is 10 to 10%.
50ppm, the amount is extremely low (CKShu,
J.P. Walradt, WITaylor; J.of
Chromatography 106, P.271-282, 1975). This is an insufficient content to consider bergapten alone as a causative substance, and suggests the presence of other causative substances. Regarding the phototoxicity of lemon oil, the present inventors conducted a detailed study on the relationship between the components of lemon oil and phototoxicity using a combination of distillation, fractionation using column chromatography, and a patch test. In other words, lemon oil was separated using thin-layer chromatography, and each component was confirmed using infrared absorption spectroscopy and nuclear magnetic resonance absorption spectrometry.The presence or absence of phototoxicity was confirmed using a patch test, and the cause of phototoxicity was determined. The substances were determined to be bergapten and oxypoisedanine. Of these two types of furocoumarins with phototoxic effects, oxypoisedanine was already known as a compound with 1/3 to 1/4 of the phototoxicity of bergapten (L. Musajo, G. .
Rodighiero;Experienta, Vol, P.153~
200, 1962). However, the present inventor was the first to discover that it exists in lemon oil, and the content in lemon oil was 380 ppm. We have now clarified that the phototoxicity of lemon oil can be removed by removing bergapten and oxypoisedanine. As a method for removing furocoumarins, which have phototoxic effects, from citrus oil, it is known to decompose bergamotu oil with an alkali, as reported in Japanese Patent Publication No. 35-15363. However, when this method is applied to lemon oil, distillation residue is Since all the esters and coumarins and furocoumarins in the process are decomposed and removed, a strange odor is generated and the aroma changes, making this method unsuitable for processing lemon oil, which has a delicate fragrance. The present inventor took advantage of the fact that among the furocoumarins present in lemon oil, bergapten and oxypoisedanine, which are the causative substances of phototoxicity, have a strong adsorption ability to inorganic adsorbents, and developed an excellent lemon oil without phototoxicity. Completed the method of producing oil. That is, the object of the present invention is to almost completely remove furocoumarins, especially bergapten and oxyboisedanin, which are causative substances of phototoxicity, from lemon oil using an inorganic adsorbent after insolubilizing and precipitating them in a nonpolar solvent. . In the present invention, first, lemon oil is distilled under reduced pressure. This is to minimize the amount of inorganic adsorbent treated in the next step and to ensure economical efficiency and ease of operation by using a small amount of inorganic adsorbent. Distillation under reduced pressure is carried out at a temperature and pressure that does not change the components of lemon oil, and furocoumarins are left in the residue to prevent them from being transferred to the distillate. For this purpose, the temperature and pressure can be selected from a wide range, but a range of about 100°C/5 mmHg to 120°C/10 mmHg is suitable. Next, a non-polar solvent is added to the residue after vacuum distillation, and the mixture is cooled to insolubilize and precipitate furocoumarins by utilizing the low solubility of furocoumarins in non-polar solvents, and then separated and removed. The reason for using a non-polar solvent here is to adsorb and remove furocoumarins using an inorganic adsorbent, which will be described later.
This is to insolubilize and precipitate furocoumarins in advance to reduce the use of inorganic adsorbents.This reduces the amount of aroma components attached to the inorganic adsorbent and increases the efficiency of furocoumarin removal by the inorganic adsorbent. will be promoted. Petroleum ether, n-hexane, cyclohexane, n-heptane, etc. are used as the nonpolar solvent. Next, an inorganic adsorbent is added and stirred to adsorb furocoumarins, especially bergapten and oxypoisedanine. Silica gel, alumina, and mixtures thereof are used as inorganic adsorbents. After separating the inorganic adsorbent and washing and extracting the remaining aroma components attached to it using other solvents such as toluene, dichloroethane, ethyl acetate, etc. in addition to the above-mentioned non-polar solvent,
The solvent is recovered by distillation under reduced pressure, and the distillation residue is collected as refined oil. This product is combined with the oil obtained by the vacuum distillation described above to form a product. The non-phototoxic lemon oil obtained in this way has not undergone any chemical changes, so it does not have any unpleasant odor.
It retains the aroma of natural lemon oil without loss, and has a scent rich in so-called naturality. In addition, this manufacturing method does not cause pollution due to industrial wastewater discharge because it is treated in a non-aqueous system, does not require delicate skill unlike the conventional known method using alkali treatment, and is a manufacturing process that consists of highly reproducible steps. It is the law. A patch test confirmed that the obtained product was an excellent lemon oil with no phototoxicity. Next, the present invention will be explained with reference to Examples and Reference Examples. Example 1 1.0Kg of lemon oil was distilled under reduced pressure at 100℃/5mmHg.
960 g of colorless oil was obtained. Next, add 200ml of n-hexane to 40g of the residue,
After stirring, the mixture was allowed to stand at -20°C for 12 hours to precipitate insolubilized substances. 80 g of silica gel was added to the solution, which was filtered to remove insolubilized materials, stirred for 15 minutes, and filtered to separate the n-hexane layer and the silica gel. Add 160ml of toluene to the separated silica gel and wash it.
The aroma components attached to the silica gel were extracted. n-
Distill the hexane layer and toluene layer under reduced pressure to create an n-
Hexane and toluene were recovered to yield 16 g of a dark brown oil. This oil and the initially obtained colorless oil were thoroughly mixed to obtain 976 g of refined lemon oil.
This lemon oil was determined by high performance liquid chromatography.
It was confirmed that it did not contain bergapten and oxypoisedanine. Example 2 1.0 kg of lemon oil was treated in the same manner as in Example 1, except that the silica gel was washed with 160 ml of dichloroethane, to obtain 980 g of the desired product. Example 3 1.0Kg of lemon oil was distilled under reduced pressure at 100℃/5mmHg
690 g of colorless oil was obtained. Next, add 200ml of n-pentane to 40g of the residue,
After stirring, the mixture was allowed to stand at -20°C for 12 hours to precipitate insolubilized substances. 80 g of activated alumina was added to the solution from which insolubilized matter had been removed, and the mixture was stirred for 20 minutes and filtered to separate the n-pentane layer and the alumina. Add 160ml of n-hexane and ethyl acetate to the separated alumina.
A 90:10 mixed solution was added to wash the alumina, and the aroma components attached to the alumina were extracted. The pentane layer and the n-hexane-ethyl acetate mixture layer are distilled under reduced pressure to obtain pentane and n-hexane.
Collect the ethyl acetate mixture and obtain 18g of dark brown oil.
I got it. This oil and the initially obtained colorless oil were thoroughly mixed to obtain 978 g of refined lemon oil. Reference Example 1 A comparative test of phototoxicity between lemon oil and that prepared according to the examples of the present invention was conducted. As a phototoxicity test method, first, the hair on the back of a healthy Hartley white guinea pig weighing 450 to 550 g was clipped, and then the hair was removed using a hair removal cream. After 24 hours, the guinea pigs were fixed in a fixator in the ventral position. 0.02 ml of the sample solution (essential oil stock solution and ethanol diluted solution) was applied in two rows to a 1.5×1.5 cm ² dorsal hair removal site. 1
The column was covered with aluminum foil to block light, and light irradiation was started. The light source is six Toshiba BLB 40W fluorescent lamps equipped with a glass filter (wavelength range 320
~400 nm), and irradiated for 110 minutes (1.1×10 ⁸ ergs/cm ² ) from a distance of 10 cm from the back of the guinea pigs.
Judgments were made 24 hours and 48 hours after the end of irradiation using the following ratings. (Evaluation) No macroscopic change 0 Mild or mottled erythema 1 Moderate erythema 2 Severe erythema and edema 3 UV (+) of unshaded area and UV of shaded area
The reaction with (-) was compared, and the case where the reaction was strong in the part not shielded from light was judged to be phototoxic. The average reaction intensity was calculated as follows. Average reaction intensity = total score of each guinea pig/number of guinea pigs used in the experiment Test results: In the table, the numbers in parentheses in the UV (-) and UV (+) sections represent the average reaction intensity, and the denominator The number in the numerator represents the number of guinea pigs used in the experiment, and the number in the numerator represents the number of guinea pigs that responded to the stimulus.

[Table] As a result, all commercially available lemon oils have a significant phototoxic effect, but no phototoxicity was detected in the lemon oil according to the example of the present invention.

Claims (1)

[Claims] 1 Lemon oil is distilled under reduced pressure at a temperature and pressure of 120°C/10 mmHg or less to obtain a distillate oil, and a nonpolar solvent is added to the distillation residue to insolubilize furocoumarins. Phototoxicity characterized in that the oil obtained by removing the precipitated and removing the remaining furocoumarins by adding an inorganic adsorbent to adsorb and remove the remaining furocoumarins and then removing the solvent is combined with the distillate oil. A method for producing lemon oil that does not have 2. The manufacturing method according to claim 1, wherein the inorganic adsorbent is silica gel or alumina.