JPH01157909A - Ultraviolet ray absorber - Google Patents

Abstract

PURPOSE:To obtain an ultraviolet ray absorber, consisting of an extract of licorice with an organic solvent and having remarkable absorption within a long wavelength ultraviolet ray region with high safety. CONSTITUTION:An ultraviolet ray absorber, consisting of an extract of a leguminous plant Glycyrrhiza glabra var. glandulifera Reder et Herder, preferably Glycyrrhiza echinata L. produced in Hsinchiang in China or Glycyrrhiza inflata Batal. with an organic solvent and having remarkable absorption within a longwavelength region of 320-400nm wavelength (i.e., having absorption maximum). A lower aliphatic alcohol, lower aliphatic ketone, lower aliphatic ether, volatile hydrocarbon, etc., are used as the organic solvent for extraction. The raw material to be treated is dipped in the solvent in an amount of 3-5times and heated while being refluxed or dipped therein in an amount of 5-10times at ordinary temperature to carry out the extraction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to ultraviolet absorbers, particularly UV absorbers with wavelengths of 320 to 400 a.
This invention relates to an ultraviolet absorber that has significant absorption in the +a long wavelength region.

[Conventional technology]

The ultraviolet rays included in sunlight and reaching the ground are 290-3
20 nm medium wavelength ultraviolet rays (so-called UV-B) and 320 nm
~400IIIm long wavelength ultraviolet rays (so-called UV-A)
It is broadly divided into. Furthermore, UV-B is known to have negative effects on the human body, such as accelerating skin aging and causing or worsening of age spots and freckles, and preventive measures have been considered from an early stage. ,It has been implemented.

On the other hand, since UV-A does not have any significant harmful physiological effects like UV-B and is effective for tanning beautifully, there has not been much interest in protecting against UV-A. However, it has been recently confirmed that the amount of UV-A irradiation on the earth's surface is about 15 times that of UV-B, and that it reaches the dermis. It has come to be expected that it will bring about microchronic changes in elastic fibers and promote the physiological effects of UV-B, and there has been a great deal of interest in UV-A protection measures.

The most common means of protecting against ultraviolet rays is the use of ultraviolet absorbers. The ultraviolet absorber is selected from substances that have particularly strong absorption in the ultraviolet region, and is mixed into various base materials to form ultraviolet cut filters. However, U
Until now, there were very few UV absorbers that were effective against V-A, and even if there were, they were synthetic products, and there were almost no confirmed safety products that could be mixed into cosmetics or other products that were applied directly to the skin. .

[Problem that the invention seeks to solve]

In view of the above-mentioned current situation, an object of the present invention is to provide a UV-A ultraviolet absorber made of highly safe natural products.

[Failure to solve the problem]

The present inventor is a legume, licorice (GLYCYRIllll).
During research on I2AE RADI, it was found that certain types of licorice contain substances that exhibit significant absorption in the UV-A region. This ultraviolet-absorbing substance is extracted from licorice using an organic solvent, but its content varies depending on the many types of licorice, its production area, the year of harvest, etc., and the variation among species is particularly marked, with some species rarely containing it. be. As far as the present inventor has confirmed, it is the so-called Xinjiang licorice (multiple species are mixed) that contains this ultraviolet absorbing substance at a high rate.
yrrhizx 1nflxta Batal.

has the highest content rate.

The above-mentioned ultraviolet absorbing substance is easily extracted from licorice using an organic solvent, and its UV-A absorbing ability can be confirmed in the form of a crude extract.

Based on the above findings, the present invention provides an ultraviolet absorber comprising an organic solvent extract of licorice that has significant absorption (that is, has an absorption maximum point) in the UV-A region of wavelengths 320 to 400 nm. It is something to do.

The method for obtaining the above-mentioned active ingredient of the ultraviolet absorber of the present invention from licorice will be explained in more detail.

As the raw material licorice, one that has been confirmed in advance to contain the above-mentioned active ingredients by experiment is used, but licorice from Xinjiang or Glycyrrhizs 1n is used.
flxLa Batal.

If so, it is certain that it contains a high percentage of the active ingredient.

Since the UV-absorbing substances in licorice are not soluble in water, the licorice for extraction must be extracted with licorice water (or a water-containing organic solvent) and the extraction residue (
For example, it may be a residue obtained by extracting glycyrrhizin from licorice). Examples of organic solvents for extracting active ingredients include lower aliphatic alcohols such as methanol and ethanol; lower aliphatic ketones such as acetone and methyl ethyl ketone; lower aliphatic ethers such as dioxane and ethyl ether; petroleum ether, n-hexane, and cyclohexane. , volatile hydrocarbons such as toluene and benzene; methylene chloride,
Examples include halogenated hydrocarbons having 1 to 4 carbon atoms such as chloroform; esters having 3 to 7 carbon atoms such as ethyl acetate, D-propyl acetate, and isobutyl acetate; and mixtures of two or more of these solvents. To extract the active ingredients from licorice using these solvents, the raw material to be treated can be immersed in about 3 to 5 times the amount of extraction solvent and heated under reflux, or soaked in about 5 to 10 times the amount of extraction solvent at room temperature. Just soak it. The extract obtained by distilling off the solvent from the obtained extract is a brown solid with a characteristic odor. This extract can often be used directly as a UV absorber, but
If necessary, it may be used after being subjected to purification treatments such as deodorization and decolorization as long as its efficacy is not affected.

The method of using the ultraviolet absorber of the present invention is not particularly limited, but when it is included in various skin cosmetics such as lotions, creams, milky lotions, and packs, it is usually 0.0O
In the range of 5% to 1%, it may be mixed with a dissolving base or auxiliary agent (for example, alcohol, higher fatty acids, emulsifiers such as monoglycerides, 1,3-butylene glycol, propylene glycol, fats and oils, etc.) as necessary. . Also,
It may be used in combination with other UV-A absorbers or UV-B absorbers.

[Action/Effect]

As mentioned above, the ultraviolet absorber of the present invention is effective in the UV-A region, for which there were few suitable ones in the past, and it is obtained from licorice, which has been used as a medicine for a long time and whose safety has been confirmed. Therefore, it is extremely advantageous as a raw material for producing cosmetics and the like that have UV-A blocking ability.

〔Example〕

The present invention will be explained below with reference to Examples. The licorice used on each side was Glycyrrhixx 1nf
It is a licorice from Xinjiang that contains about 70% of lxtx Bstill.

Example 1 1 kg of ground grass roots was heated under reflux for 2 hours with 511 ethyl ether to extract ethyl ether soluble components. The same operation was repeated for the extraction residue from which the extract was separated to obtain a total of 9 extracts. The solvent of this extract was distilled off, and the extract was further dried under reduced pressure to obtain 30 g of an extract. This is referred to as ultraviolet absorbent A.

Example 2 2 kg of ground grass roots was dissolved in 10α ethyl acetate at room temperature.
The ethyl acetate soluble components were extracted by soaking for a period of time. The same operation was repeated for the extraction residue from which the extract was separated, and a total of 1111 extracts were obtained. The solvent of this extract was distilled off, and the extract was further dried under reduced pressure to obtain 101 g of an extract. This is referred to as ultraviolet absorbent B.

Example 3 10α of a mixed solvent consisting of 5 parts of n-hexane and 2 parts of acetone and 1 kg of ground grass roots were heated under reflux for 2 hours to extract solvent-soluble components. The same operation was repeated for the extraction residue from which the extract was separated, and a total of 1911 extracts were obtained. The solvent of this extract was distilled off, and the extract was further dried under reduced pressure to obtain 26 g of an extract. This is referred to as ultraviolet absorbent C.

Test Example Ultraviolet absorbers A-C were dissolved in ethanol to a concentration of 80p.
pm solution, and the absorbance at 220 to 440 nm was measured using a spectrophotometer using ethanol as a control solution. The results are shown in Figure 1, and UV-B at 290-320 nm
It had strong absorption in the UV-A region of 320 to 400 nm.

Usage example ■ Stearic acid 15.0% Cetano 1.0 Ultraviolet absorber B 005UV-B absorber (commercial product) 0.5 ■ Propylene glycol 3.0 Glycerin 5.0 Potassium hydroxide
0.7 Sterilization/preservative
Appropriate amount of purified water 74.0
■Fragrance °0.3 Heat and dissolve the above ■ at 82°C and ■ at 80°C, and while stirring, gradually add ■ to ■ to emulsify. Thereafter, ① was added at 50°C, and the mixture was cooled to 30°C and filled into a container.

As a result of the above, a sunburn prevention cream was obtained which had absorption ability in both UV-ASUV-B ranges and was more effective than conventional products.

[Brief explanation of the drawing]

FIG. 1 is an ultraviolet absorption curve of a product according to an example of the present invention.

Claims (3)

[Claims] (1) Organic solvent extract of licorice with a wavelength of 320 to 40
An ultraviolet absorber having significant absorption in the long wavelength ultraviolet region of 0 nm. (2) The ultraviolet absorber according to claim 1, which comprises an organic solvent extract of licorice from Xinjiang. (3) Glycyrrhiza inflata Ba
tal. Claim 1 consisting of an organic solvent extract of
Ultraviolet absorber as described in section.