JPS6215539B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing high-purity phytol from unsaponifiable substances of plants and algae.

Phytol is a synthetic raw material for useful pharmaceuticals such as vitamin E and vitamin K, and is also used in cosmetics. Conventionally, phytol has been purified using column chromatography, distillation, etc. using unsaponifiable materials obtained by saponifying chlorophyll obtained from green-leaved plants and algae. However, the former method requires a large amount of auxiliary materials such as carriers and solvents;
Moreover, it is time-consuming and unsuitable from an industrial standpoint. In the latter method, even if the distillation is repeated several times, the resulting phytol has a poor color tone and the recovery rate is low, making it difficult to efficiently obtain a highly purified product.

Therefore, the present inventors conducted various studies on separation and purification methods for high-purity phytol, and completed the present invention with the aim of providing a method for easily producing phytol of good quality.

That is, the method of separating and purifying high-purity phytol according to the present invention involves reacting crude phytol obtained by distillation or solvent extraction from unsaponifiable substances of plants and algae with a dibasic acid anhydride in a nonpolar solvent to obtain a hemiester of phytol. The method is characterized in that it is purified by adsorption with a weakly basic or medium basic anion exchange resin in the presence of a mixed solvent of the nonpolar solvent and an alcoholic solvent. By this ion-exchange resin treatment, the hemiesterified product of phytol is adsorbed on the resin and separated from impurities, and the adsorbed hemiesterified product is desorbed with an alkali and hydrolyzed to easily recover phytol.

The notable advantages of the present invention are that the phytol obtained is of high purity and good color, that the recovery rate is high, and that the manufacturing process is simple and does not require any complicated equipment.

To explain the present invention in more detail, when phytol is induced into an acid ester, phytol has unsaturated bonds at the α and β positions of the hydroxyl group. Reactions are likely to occur. In the present invention, in order to avoid this side reaction, the acid anhydride of the dibasic organic acid used is used. When this acid anhydride is used, the reaction proceeds either under a basic catalyst or without a catalyst, and no intramolecular dehydration reaction of phytol occurs under these conditions. Examples of dibasic acid anhydrides that can be used in this reaction include maleic anhydride, phthalic anhydride, and succinic anhydride. The amount of dibasic acid anhydride used is the OH in the unsaponifiable materials of the raw material.
Determined based on price. That is, unsaponifiable materials such as plants and algae contain higher alcohols, sterols, etc. in addition to phytol, and since these also form esters, it is necessary to use an excess amount thereof. Reaction solvents are benzene, toluene, hexane,
Non-polar solvents such as cyclohexane are preferred.

The ion exchange resin that can be used in the present invention can be used to obtain a high recovery rate, since with strongly basic ion exchange resins, some of the hemiesters tend to return to hydrolyzed phytol during passage, leading to a decrease in recovery rate. For this purpose, it is necessary to use a weakly basic ion exchange resin, preferably a medium basic ion exchange resin.

Considering the solubility of the crude phytol and the solvent used in the hemiesterification reaction, the solvent used in the ion exchange resin treatment is a mixed solvent of the nonpolar solvent used in the hemiesterification reaction and an alcoholic solvent in the adsorption step.

If a non-polar solvent is used alone, a portion of the hemiester compound tends to be hydrolyzed during passage, becoming phytol, and flowing out without being adsorbed to the resin.If an alcohol solvent is used alone, has the disadvantage of poor solubility of hemiesterified products. On the other hand, an alcoholic solvent is required to dissolve the alkali necessary for hydrolyzing the hemiester adsorbed onto the resin into phytol and regenerating the resin. On the other hand, by using a mixed solvent of a nonpolar solvent and an alcoholic solvent, the above-mentioned drawbacks of using each solvent alone can be overcome, and since it is also possible to dissolve alkali, the adsorbed hemiester can be dissolved. Hydrolysis to phytol and regeneration of the resin can be performed simultaneously. Therefore, it is possible to add an alcoholic solvent to a solution of a nonpolar solvent obtained in the hemiesterification reaction and pass it through the resin to adsorb the hemiesterified product to the resin, and it is also possible to add an alkali to the same mixed solvent. By passing liquid through the resin, the resin can be regenerated and the hemiester compound can be hydrolyzed into phytol at the same time. The phytol produced by the alkali hydrolysis of the hemiester is well dissolved in the nonpolar solvent in the mixed solvent, and the dibasic acid that is purified at the same time is dissolved in the alcoholic solvent and flows out.

When crude phytol is processed by the method of the present invention, phytol can be obtained in high yield and sufficiently purified.
If the obtained phytol is further distilled, highly purified phytol with high transmittance can be obtained, which has high industrial value.

Next, an example will be given and explained.

Example 1 Crude phytol obtained by molecular distillation of unsaponifiables obtained from chlorella (phytol content GLC value
54.2%, OH value 65.0%) was dissolved in 80 ml of toluene, heated, and 10 ml of toluene was distilled off to remove water from the reaction system. Add 16.69 g of succinic anhydride (1.1 mol equivalent to OH value) to this,
Heat to reflux while stirring for 1.5 hours. After cooling, wash with warm water. Further, 210 ml of methanol was added to the obtained succinic acid hemisester-toluene solution to obtain a feed material. Thin layer chromatography (silica gel carrier, chloroform developing solvent) revealed that almost no unreacted phytol was present in the hemiesterified product thus obtained.

Next, medium basic anion exchange resin Diamond ion
Pass the liquid through a column packed with 250 ml of WA10. Further, the resin is washed with a mixture of toluene and methanol (1:3) in an equal amount. The effluent obtained during this time is separated as a non-adsorbed liquid. Next, 5.6% potassium hydroxide/toluene-methanol (1:3) mixture was passed through the resin in an amount 1.5 times the amount of the resin for desorption and regeneration.
Pour twice the volume and wash. After concentrating the effluent obtained from this regeneration and washing, 50ml of toluene was added to the residue, washed with warm water, and the solvent was distilled off, resulting in a content of 83.5%.
40.10 g of adsorbed oil and a recovery rate of 90.2% were obtained. Further, when this adsorbed oil was distilled (170°C, 2 mmHg), 32.89 g of phytol with a content of 96.9% and a transmittance of 85.0% (measured at a wavelength of 415 nm) with a good hue was obtained.

Example 2 Crude phytol obtained from spinach unsaponifiables by solvent extraction (phytol content GLC value 25.0)
%, OH value 29.5%) was dissolved in 120 ml of toluene and heated to remove water from the reaction system. To this was added 10.94 g of succinic anhydride (equivalent to OH value: 1.1 mol), and the mixture was heated under reflux with stirring for 1.5 hours. After cooling, wash with warm water. An additional 300 ml of methanol was added to the obtained succinic acid hemisester-toluene solution to obtain a feed material.

Next, medium basic anion exchange resin Diamond ion
Pass the liquid through a column packed with 250 ml of WA10. Next, the resin is washed with a mixture of toluene and methanol (1:3) in an equal amount. The effluent obtained during this time is separated as a non-adsorbed liquid. Next, 5.6% potassium hydroxide/toluene-methanol (1:3) mixture was passed through the resin in an amount 1.5 times the amount of the resin for desorption and regeneration.
Pour twice the volume and wash. After concentrating the effluent obtained from this regeneration and washing, 50 ml of toluene was added to the residue, and after washing with warm water, the solvent was distilled off to obtain 27.42 g of adsorbed oil with a content of 80.5% (recovery rate of 88.3%).

Claims (1)

[Claims] 1. Crude phytol obtained by distillation or solvent extraction from unsaponifiable substances of plants and algae is reacted with dibasic acid anhydride in a non-polar solvent to obtain a hemi-esterified product of phytol, which is mixed with the above-mentioned non-polar solvent and an alcoholic solvent. A method for separating and purifying high-purity phytol from unsaponifiable substances of plants and algae, which comprises adsorption and purification with a weakly basic or medium basic anion exchange resin in the presence of a mixed solvent with phytol.