JPH05271084A - Water-soluble ginkyo leaf extract and its prouction - Google Patents

Abstract

PURPOSE:To convert a water-insoluble ginkyo extract into a water-soluble ginkyo extract in a high yield by an easy means. CONSTITUTION:The water-soluble ginkyo leaf extract is obtained by subjecting a ginkyo leaf extraction solution controlled to a pH of >=6 to a concentrating and drying treatment. The water-soluble ginkyo leaf extract is produced by mixing a water-insoluble ginkyo leaf extract extracted by the use of a water- containing organic solvent with hot water or a water-containing organic solvent, adding a basic compound to the produced solution to control the pH of the solution to >=6.0, and subsequently concentrating and drying the controlled solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a ginkgo leaf extract which can be easily dissolved in water.

[0002]

2. Description of the Related Art For the past ten years, a therapeutic drug containing a hydrous organic solvent extract obtained from ginkgo leaves as a main component has been used in Germany and France for the purpose of improving cerebral arteries and peripheral blood vessels. It is widely used as a pharmaceutical product. Ginkgo biloba extract has been clinically recognized to have effects such as improving blood circulation without increasing blood pressure, and improving senile dementia and peripheral vascular disorder, Raynaud's disease, and various diseases caused by diabetes. In addition, it has been recognized that it has an action of removing active oxygen and an anti-allergic action recently. Moreover, few side effects have been observed. Therefore, it is being marketed not only as a medicine but also as a health food, and is becoming widespread.

However, the above-mentioned hydrous organic solvent extract obtained from ginkgo leaves has a major drawback that it is insoluble in water. Therefore, the hydrous organic solvent extract has been generally used as a tincture mainly dissolved in an aqueous solution containing 50% alcohol, or as a solid preparation or the like in which the powder of the extract is directly used as a tablet. However,
A purification method for making the above-mentioned hydrous organic solvent extract soluble in water has also been provided for use in injections and the like.

As a method for purifying such a water-insoluble leaf extract of the leaves, for example, the above-mentioned hydrous organic solvent extract is treated with an organic solvent such as toluene or butanol, followed by centrifugation, contact with a special absorbent resin, etc. In the same manner as in the method of purification through 7 to 8 steps, the hydrous organic solvent extract is extracted with a fat-soluble solvent, and the precipitation, filtration, and concentration are repeated using ammonium sulfate, methyl ethyl ketone and lead acetate alcohol aqueous solution, and then, Method of mixing with high molecular weight polyamide powder and refining, water-containing organic solvent extract once pH
A method has been proposed in which a strong alkali having a pH of 8.0 or higher, preferably pH 14, is prepared, and then acidified to pH 1 with sulfuric acid, ammonium sulfate is further added, and re-extraction is performed with butanone and an acetone solvent for purification.

However, these proposed methods ~
The process of purifying a water-insoluble extract of ginkgo leaves is many and complicated. Further, the extraction rate of the target ginkgo leaf extract is low, there is a loss of the active ingredient, and there is a problem that quality variation easily occurs between lots of the refined product. Further, in the case of a purification method using toluene or butanone whose use is prohibited in food production, the obtained refined product can be used as a pharmaceutical raw material but is not approved as a food raw material and its use is limited. There was a flaw. Further, there is a problem that toxic lead acetate and the above-mentioned organic solvent remain in the purified product. Further, since the refining is complicated and requires many steps, the manufacturing cost is very high.

Then, as a result of earnest studies, the present inventors have solved the above-mentioned problems and completed a method for obtaining a water-insoluble extract of ginkgo biloba which contains a sufficient amount of active ingredients. Therefore,
An object of the present invention is to provide a method for obtaining a water-insoluble leaf extract that has been extracted using a water-containing organic solvent as a water-insoluble leaf extract that does not lose the active ingredient. Another object of the present invention is that it can be used as an injection, is easily used as a food material such as a drink, and can also be easily used as a raw material for cosmetics. The purpose is to provide an extract of ginkgo biloba.

[0007]

The hydrous organic solvent extract obtained from ginkgo leaves is a complex natural product containing many components other than the active ingredients flavonoids and terpene lactones. Those who have dissolved the above-mentioned water-containing organic solvent extract in hot water or water-containing ethanol etc. add a basic compound to adjust the pH of the solution to 6.0 or more, and then filter or dry it to obtain water. It has been found that a ginkgo leaf extract that is well soluble is obtained.
That is, the present invention includes (1) a water-insoluble ginkgo biloba extract obtained by concentrating and drying a ginkgo biloba extract solution adjusted to pH 6 or higher, and (2) water extracted using a water-containing organic solvent. Is mixed with hot water or a water-containing organic solvent, and then a basic compound is added to the solution to add p.
(3) A method for producing a water-insoluble extract of ginkgo leaves, which comprises concentrating and drying after adjusting H to 6.0 or more;
Water-insoluble butterflies extract extracted with a water-containing organic solvent was mixed with hot water or a water-containing organic solvent, and then a basic compound was added to the solution to adjust the pH to 6.0 or more and then filtered. A method for producing a water-insoluble butterfly extract, comprising concentrating and drying the obtained filtrate, and (4) adding a basic compound solution to the water-insoluble butterfly extract,
In the method for producing a water-insoluble leaf extract, which comprises concentrating and drying after adjusting the pH to 6 or more, and (5) in the step of obtaining a water-insoluble leaf extract, a basic compound is added. It is a method for producing a water-insoluble extract of ginkgo biloba, which comprises adding to form a solution having a pH of 6 or more and then concentrating and drying.

In the method of the present invention, the water-insoluble extract of ginkgo leaves can be dissolved in hot water or a water-containing organic solvent at any concentration, but at this time, water alone or an aqueous solution containing a low content of the organic solvent is used. In this case, it may be heated and dissolved. The pH of this solution is usually on the acidic side and is about 3 to 5. Then, a basic compound such as an aqueous solution of sodium hydroxide is added to this solution to adjust the pH of the solution to 6.0 or more. The pH is more preferably adjusted to 6.5 or higher, and particularly preferably pH 7.5 or higher. The hot water or the low content organic solvent aqueous solution containing the ginkgo biloba extract whose pH is adjusted to 6 or more contains a small amount of water-insoluble precipitate when the temperature is lowered to about room temperature, but the solution is concentrated and dried as it is. By solidifying, a target water-insoluble leaf extract can be obtained. When a solid substance is mixed in the solution, it is filtered and then concentrated,
It is preferable to dry it, and as a result, a highly purified water-insoluble leaf extract can be obtained. According to the method of the present invention, except for adjusting the pH, a particularly complicated operation is not required, and approximately 10% of the water-insoluble extract of ginkgo leaves is obtained.
It can be obtained with a yield of 0%.

The pH adjustment in the present invention can also be carried out in the process of purifying a water-insoluble extract of a clove leaf extracted with a water-containing organic solvent. It is particularly preferable to carry out before the final concentration step of the purification. In the present invention, the basic compound used for pH adjustment includes compounds exhibiting basicity, for example, alkali metal and alkaline earth metal hydroxides, carbonates, bicarbonates, phosphates and metaphosphates. In addition, ammonium salts such as ammonium hydrogen carbonate and ammonium citrate, alkylamines, polyalkylamines, aqueous ammonia and the like can also be mentioned. In any case, the compound is not limited to these as long as it is a basic compound. Among the basic compounds, as a result of the experiment, the use of the weakly basic compound was preferable.

In the above description, the water-insoluble leaf extract is extracted from ginkgo leaf using a water-containing organic solvent such as water-containing methanol, water-containing ethanol, water-containing acetone, and water-containing methyl ethyl ketone, and the obtained extract is then extracted. A solid obtained as a result of a combination of operations such as concentration, filtration, column treatment, and re-extraction with an organic solvent. The extract sufficiently contains flavonoid glycosides as an active ingredient, and 1 g thereof is 100 ml. Refers to the insoluble extract of water.

[0011]

EXAMPLES Next, the present invention will be specifically described by way of examples. Example 1: 20 v / v of 10 g of water-insoluble extract of ginger leaf extract containing about 24% of commercially available flavone glycoside
The mixture was mixed with 100 ml of an aqueous solution containing% ethanol and heated to 60 ° C. to dissolve. The pH of this solution was 3.8.
Then, a 10% aqueous solution of ammonium hydrogen carbonate was added to this solution to adjust the pH to 6.2. The pH-adjusted solution was sufficiently concentrated with an evaporator to obtain 9.6 g of brown water-soluble powder. Since the water content of the above-mentioned starting material, which is a water-insoluble extract of ginkgo leaves, was 5%, the yield of the water-insoluble extract of ginkgo leaves was almost 100%. When 1 g of the obtained brown powder was dissolved in 10 ml of water,
It dissolved almost transparently. The pH of the solution was 6.1.

Example 2 2 10 g of the same water-insoluble extract of ginkgo leaf as that used in Example 1 was mixed with 100 ml of water, and the mixture was heated at 75 ° C. in a water bath.
When heated, the solution became opaque but almost dissolved.
Next, a 10% aqueous solution of sodium hydrogen carbonate was added to this solution to adjust the pH to 7.5. After adjusting the pH, the mixture was well stirred for 5 minutes while maintaining the same temperature, and then allowed to cool to room temperature. Then, the solution was gravity filtered, and the filtrate was sufficiently concentrated with an evaporator to obtain 9.5 g of water-soluble brown powder.
0.1 g of water-insoluble solid matter remained on the filter paper. When 1 g of the obtained brown powder was dissolved in 10 ml of water, it was completely transparent and well dissolved. The pH of the solution is 7.5.
Met.

Example 3 3 10 g of the same water-insoluble extract of ginkgo biloba used in Example 1 was added to an aqueous solution containing 50 v / v% ethanol.
It was dissolved in 0 ml at room temperature. Next, aqueous ammonia (ammonia concentration 28%) was added to this solution to adjust the pH to 10.0. Then, the solution was directly concentrated under reduced pressure to give 9.7 g.
A brown water-soluble powder was obtained. When 1 g of the obtained brown powder was dissolved in 10 ml of water, it was transparently dissolved.
The pH of the solution was 6.8.

Example 4: 4 20 g of the same water-insoluble extract of ginkgo leaf as used in Example 1 was added to a 30% aqueous solution containing 10 v / v% ethanol.
It mixed with ml and heated at 76 degreeC, and melt | dissolved. Next, 1% caustic soda aqueous solution was added to this solution to adjust the pH to 8.6. Then, suction filtration was carried out, and then the filtrate was concentrated under reduced pressure to obtain 19.0 g of brown water-soluble powder. Upon filtration with suction, 0.7 g of water-insoluble solid remained on the filter paper.
When 1 g of the obtained brown powder was dissolved in 10 ml of water, most of it was dissolved but there was a slight turbidity. In addition,
The pH of the solution was 6.8.

Example 5 5 To 500 g of dried ginkgo leaves, 5000 ml of 70
% Acetone aqueous solution was added, and the mixture was heated at 55 ° C. for 2 hours. Then, this was subjected to suction filtration for solid-liquid separation, and the obtained liquid was concentrated under reduced pressure to a volume of about 500 ml. And 50
0 ml of water was added, the mixture was cooled to room temperature and then filtered to remove the precipitated hydrophobic substance. The obtained filtrate was passed through a glass column filled with 500 ml of a gel filtration filler (Toyopearl HW-40) to adsorb the ginkgo leaf extract. Subsequently, 1000 ml of water was poured into the gel filtration filler adsorbing the ginkgo leaf extract to wash it, and then 1000 ml of a 70% aqueous ethanol solution was supplied to desorb and elute the adsorbed extract. A 10% potassium hydrogen carbonate aqueous solution was added to this eluate to adjust the pH to 7.5. Then, the solution was concentrated to dryness under reduced pressure to obtain 14.0 g of a brown water-insoluble leaf extract of brown leaves containing 25% of flavone glycoside.

As shown in the above examples, according to the method of the present invention, a water-insoluble extract of cucumber leaf can be easily made soluble in water. Then, in the method of the present invention, if a weakly basic compound is used as the basic compound,
There is no change in the pH value of the pH adjustment solution in the intermediate step and the aqueous solution of the obtained water-insoluble leaf extract powder,
Therefore, it was found that it is suitable for the production of injections and the like.

[0018]

As described in detail above, according to the present invention, a water-insoluble extract of ginger leaves extracted with a water-containing organic solvent is soluble in water by an easy means without losing the active ingredient. It is possible to make it as a ginkgo leaf extract. Also,
Although the method of the present invention is extremely simple as compared with the conventional method, it has a very high conversion yield to a water-insoluble extract of ginkgo biloba. And, by using the obtained water-insoluble butterfly leaf extract of the present invention, an injection can be easily produced, or various beverages and foods to which the leaf extract is added are easily produced. be able to.
Further, a wide variety of products containing the ginkgo leaf extract can be easily provided, for example, cosmetics to which the ginkgo leaf extract is added, in particular, lotions can be easily produced.

Claims (5)

[Claims] 1. A water-insoluble ginkgo biloba extract obtained by concentrating and drying a ginkgo biloba extract solution adjusted to pH 6 or higher. 2. A leaf extract that is insoluble in water and extracted with a water-containing organic solvent is mixed with hot water or a water-containing organic solvent,
Then, a basic compound is added to the solution to adjust the pH to 6.0 or more, and the solution is concentrated and dried, which is a method for producing a water-insoluble extract of a butterfly. 3. A leaf extract that is insoluble in water and extracted using a water-containing organic solvent is mixed with hot water or a water-containing organic solvent,
Then, a basic compound is added to the solution to adjust the pH to 6.0 or more, the mixture is filtered, and the obtained filtrate is concentrated and dried. 4. A method for producing a water-insoluble leaf extract, which comprises adding a basic compound solution to a water-insoluble leaf extract to adjust the pH to 6 or more, and then concentrating and drying. .. 5. A water-insoluble leaf extract, characterized in that, in the step of obtaining a water-insoluble leaf extract, a basic compound is added to form a solution having a pH of 6 or more, followed by concentration and drying. Method of manufacturing things.