JP2009062337A - α-Glucosidase activity inhibitor and food containing the same - Google Patents

Abstract

An object of the present invention is to provide an α-glucosidase activity inhibitor that can be easily extracted from cells and is easily taken by a living body, and a food containing the same.
An α-glucosidase activity inhibitor containing a unicellular eukaryotic alga or an extract thereof. In particular, the unicellular eukaryotic algae is preferably Euglena or Chlorella. The extract preferably contains a component extracted with a lipophilic solvent, specifically a glycolipid. Moreover, the food which has a high added value containing the said alpha-glucosidase activity inhibitor.
[Selection figure] None

Description

  The present invention relates to an α-glucosidase activity inhibitor and a food containing the same, and more particularly to an alga-derived α-glucosidase activity inhibitor and a food containing the same.

α-Glucosidase is an enzyme that cleaves the α-glucoside bond at the non-reducing end of disaccharides such as sucrose and sucrose and decomposes them into monosaccharides such as glucose. α-Glucosidase is localized mainly in the small intestinal epithelium and has an important role as a carbohydrate digestive enzyme in the living body, and is particularly known to be involved in an increase in blood glucose level.
Therefore, it is considered that the increase in blood glucose level can be suppressed by suppressing the activity of α-glucosidase, which leads to prevention and treatment of diseases such as diabetes and obesity caused by hyperglycemia, and improvement of symptoms. .

  Conventionally, as an α-glucosidase activity inhibitor derived from a multicellular eukaryotic algae, for example, a substance containing a fluorotannin contained in both or one of seaweed Ezoicige and Hibamata (Patent Document 1), Amanori sulfate polysaccharide The thing containing the low molecular decomposition product of porphyran (patent document 2) etc. is known.

By the way, conventionally, unicellular eukaryotic algae such as chlorella and Euglena (euglena) have high nutritional value, and thus are widely used as foods and pharmaceuticals.
For example, Euglena is classified into both zoology and botany, and is a microorganism of the order of Euglena belonging to the flagellate class in zoology and the class of Euglena algae in botany. Euglena genus microorganisms have characteristics that combine their zoological and botanical characteristics, and have been widely used as research objects in fields such as biochemistry and physiology since ancient times.

Euglena is rich in vitamins and fatty acids, which are nutrients necessary for human life, and contains Euglena-specific natural substances such as paramylon (β-1,3-glucan). It is expected to be used as a food for solving food problems and space food.
Similarly, Chlorella has a high nutritional value and is widely provided in the form of dietary supplements.

JP 2002-212095 A JP 2006-104100 A

  Since the multicellular eukaryotic algae described above grow and grow in cells, the cells are not separated at the time of collection, and when extracting an active ingredient having an α-glucosidase activity inhibitory action, the cell wall is destroyed. Cells need to be separated. For this reason, there existed a problem that a component extraction took time and the amount of components obtained per unit weight was small.

  On the other hand, unicellular eukaryotic algae are in a state where one cell constitutes one individual and the cells are separated, so that the cells are already separated and not organized at the time of collection. For this reason, it is not necessary to perform a cell wall destruction treatment in order to take out individual cells as in the above-described multicellular eukaryotic algae, and the extraction of active ingredients from cells is easier compared to multicellular eukaryotic algae. . Therefore, the active ingredient of the unicellular eukaryotic algae has a property that it is easily extracted to the outside and easily taken into the living body.

In particular, Euglena has no cell wall and can easily destroy cells as compared to other unicellular eukaryotic algae with cell walls. For this reason, Euglena can extract the active ingredient in the cell more easily. For example, the cell wall is easily destroyed by digestion, so that the active ingredient in the cell is extracted out of the cell. Therefore, the active ingredient of Euglena has a property that it is more easily ingested by the living body than that of other unicellular eukaryotic algae.
However, it has not been known so far that unicellular eukaryotic algae from which active ingredients can be easily extracted have an α-glucosidase activity inhibitory action.

An object of the present invention is to provide an α-glucosidase activity inhibitor that can be easily extracted from cells and is easily taken by a living body.
Another object of the present invention is to provide a food with high added value, including an α-glucosidase activity inhibitor that can be easily extracted and easily taken by a living body.

  As a result of diligent efforts to achieve the above object, the present inventors have found that unicellular eukaryotic algae or extracts thereof have an action of inhibiting α-glucosidase activity, and have completed the present invention.

That is, the said subject is solved by containing the unicellular eukaryotic algae or its extract according to the alpha-glucosidase activity inhibitor of this invention.
In this case, it is preferable that the unicellular eukaryotic algae is Euglena or Chlorella.
Moreover, it is preferable that the said single cell eukaryotic algae is obtained by culture | cultivation under light irradiation.
Furthermore, it is preferable that the extract is extracted with a lipophilic solvent.
In this case, it is preferable that the extract contains a glycolipid.

  Moreover, according to the foodstuff of this invention, the said subject is solved by including the alpha-glucosidase activity inhibitor in any one of the said.

Since the α-glucosidase activity inhibitor of the present invention is obtained from unicellular eukaryotic algae in which individual cells are separated, the extraction of components is easier than in conventional multicellular eukaryotic algae, and it is taken into the living body. It has easy properties. Therefore, even if it does not perform a special extraction process, it exhibits an α-glucosidase activity inhibitory effect sufficiently and has a high effect on treatment, improvement, and prevention of diseases such as diabetes and obesity derived from α-glucosidase.
Moreover, since extraction of components is easy, high-concentration active components can be extracted by a simple operation. Therefore, a highly pure α-glucosidase activity inhibitor can be provided at a low cost.
Since the food of the present invention includes an α-glucosidase activity inhibitor that can be easily extracted and easily taken by a living body, it has a high effect on the treatment and prevention of diseases such as diabetes and obesity and the improvement of symptoms.

  Hereinafter, an embodiment of the present invention will be described. It should be noted that members, arrangements, and the like described below do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

  The “unicellular eukaryotic algae” of the present invention means a single cell eukaryotic organism that performs oxygen-generating photosynthesis, and includes, for example, Euglena, Chlorella, Botriococcus, Chlamydomonas, and Hematococcus. Genus, Chlorococcus genus and the like are included.

The “Euglena” of the present invention is a component that includes all plants classified as Euglena in zoological or botanical classification, varieties thereof, and variants thereof, and has an inhibitory action on α-glucosidase activity. Means all plants including
Here, the Euglena microorganism is a euglena euglenoidina subfamily belonging to the order of Protozoa's protozoa and Phytomastigophora in zoology. It is a microorganism belonging to the eye (Euglenoidina). On the other hand, microorganisms belonging to the genus Euglena belong to Euglenaes belonging to Euglenophyceae of Euglenophyta in botany.

  Microorganisms of euglenoids, specifically, Euglena acus, Euglena caudata, Euglena chadefaudii, Euglena deses, Euglena gracilis, Euglena granulata, Euglena intermedia, Euglena mutabilis, Euglena oxyuris, Euglena proxima, Euglena spirogyra, Euglena viridis, Euglena vermiformis Etc. Of these, Euglena gracilis, which is widely used for research, is particularly suitable.

Euglena can be cultured using a Cramer-Myers medium, a Hutner medium, a Koren-Hutner medium, a modified medium in which a partial composition thereof is changed, or the like. A Sakaguchi flask, an Erlenmeyer flask, a reagent bottle, etc. can be used for a culture container. Since Euglena to assimilate CO _2, it is preferred to pass into the medium air containing 1 to 5% CO _2. In addition, it is preferable to add ethanol to the medium so that the final concentration becomes 0.5 to 1.0% (volume ratio) because good growth is obtained. Furthermore, in order to sufficiently develop chloroplasts, it is preferable to add about 1 to 5 g of ammonium phosphate per liter of the medium. The culture temperature is usually 20 to 34 ° C., particularly preferably 28 to 30 ° C. Depending on the culture conditions, Euglena usually enters a logarithmic growth phase 2 to 3 days after the start of the culture, and reaches a stationary phase about 4 to 5 days.

Euglena may be cultured under light irradiation (light culture) or non-irradiated (dark culture), but light culture is preferred from the viewpoint of the α-glucosidase activity inhibitory action.
In the case of photoautotrophic culture using a Cramer-Myers medium or the like, the illuminance of light when performing bright culture is preferably about 5000 to 8000 Lux, and in light heterotrophic culture using a Hutner medium or a Koren-Hutner medium About 2000-8000 Lux is preferable.

In addition, the light irradiation may be performed from any direction of the culture container as long as the entire culture container is irradiated with light, for example, from both the upper surface and the side surface.
In addition, when performing dark culture, it is preferable to cover the culture vessel with a thick black cloth or the like so that light does not enter the culture vessel.

The term “chlorella” in the present invention means all plants including a plant classified into the genus Chlorella, its varieties, its mutants, and a component having an inhibitory action on α-glucosidase activity. .
Here, the plant of the genus Chlorella is a plant classified into green plant phylum (Chlorophyta), green algae (Chlorophyceae), Chlorococcaceae (Chlorococcales), Oocystisaceae (Oocystaceae).

  Examples of microorganisms belonging to the genus Chlorella include Chlorella vulgaris, Chlorella pyrenoidosa, Chlorella ellipsisidea, Chlorella sorokiniana, Chlorella regularis, and Chlorella saccharophila. Of these, Chlorella vulgaris (Chlorella vulgaris), which is widely used for research, is particularly suitable.

Chlorella can be cultured using an MBBM medium, a MAM medium, or a modified medium in which a partial composition thereof is changed. The culture vessel and culture conditions (temperature, etc.) can be the same as those described above for Euglena.
In addition, chlorella may be cultured under light irradiation (light culture) or non-irradiation (dark culture) in the same manner as Euglena, but in terms of the strength of α-glucosidase activity inhibitory action, Light culture is preferred. In this case, the illuminance is preferably about 3000 to 8000 Lux in light heterotrophic culture.

  The α-glucosidase activity inhibitor contains unicellular eukaryotic algae itself or an extract thereof. Here, the unicellular eukaryotic algae per se means a state in which the unicellular eukaryotic algae after culturing are not subjected to extraction treatment. Specifically, a microbial solution in which cultured single-cell eukaryotic algae are dissolved in a predetermined solution, a dried powder, a solid material solidified by granulation, a crushed material by ultrasonic treatment, spray drying, etc. Corresponds to a state where no extraction treatment is performed using a solvent.

  Unicellular eukaryotic algae, unlike multicellular eukaryotic algae having a strong cell wall such as seaweeds, have one cell as an independent individual and do not have a strong cell wall. For this reason, the unicellular eukaryotic algae have the property that the cells are more fragile than the multicellular eukaryotic algae and the components contained in the cells can be easily extracted. For this reason, for example, when unicellular eukaryotic algae are orally ingested, the components contained in the cells are eluted by being dissolved in the gastric juice. Thus, the unicellular eukaryotic algae exerts a sufficient α-glucosidase activity inhibitory effect by itself even without extraction with a solvent. In particular, when the cell structure is destroyed by drying by spray drying, intracellular components are more likely to elute to the outside, so the α-glucosidase activity inhibitory action is stronger than when the cell structure is not destroyed. Become.

  On the other hand, the extract of unicellular eukaryotic algae means a component extracted from the unicellular eukaryotic algae with a solvent such as water or a lipophilic solvent. As described above, the extract of the unicellular eukaryotic algae requires a lot of time for the extraction process, but the active ingredient is more concentrated than the unicellular eukaryotic algae itself, so that the α-glucosidase activity inhibitory action is strong. Then, it is preferable.

  As the lipophilic solvent (organic solvent) used for extraction, methanol, ethanol, propanol, propylene glycol, 1,3-butylene glycol, benzene, chloroform, acetone, methyl ether, ethyl ether, diethyl ether, phenyl ether, ethyl acetate One type or two or more types selected from the above are mentioned.

The α-glucosidase activity inhibitor is particularly abundant in fractions containing glycolipids and phospholipids, particularly fractions containing glycolipids, among fractions extracted from unicellular eukaryotic algae using a lipophilic solvent. Glycolipid has a stronger α-glucosidase activity inhibitory action about 20 times per unit weight than phospholipid.
Glycolipids can be extracted by first extracting total lipids using a lipophilic solvent and fractionating the total lipids with the same lipophilic solvent.
As the lipophilic solvent for extracting the total lipid, a mixed solution selected from two or more of the organic solvents described above is preferable, and specifically, a chloroform / methanol mixed solution is preferable. In addition, acetone is suitable as a lipophilic solvent for fractionating glycolipids and phospholipids from total lipids.

Of the components contained in the glycolipid, three of digalactosyl diacylglycerol (DGDG), monogalactosyl diacylglycerol (MGDG), and sulfoquinovosyl diacylglycerol (SQDG) exhibit a strong α-glucosidase activity inhibitory action. Among these, in particular, sulfoquinovosyl diacylglycerol (SQDG) exhibits a very strong α-glucosidase activity inhibitory action of about 5 times per unit weight as compared with the other two glycolipids.
Fractionation of these components from glycolipids can be performed by changing the water content of the chloroform / methanol mixture.

The reason why the inhibitory action of SQDG is strong among these three glycolipids is not clear, but is presumed to be due to the molecular structure of SQDG.
α-Glucosidase has a function of binding to a disaccharide having a structure in which two sugars are bonded by a glucoside bond, and releasing the glucoside bond. The molecular structure of SQDG has a structure that is more likely to bind to the active site of α-glucosidase than the other two glycolipids, or the structure that binds SQDG is less likely to dissociate from α-glucosidase, or This is considered to be a structure corresponding to both (a structure that is easy to bind and difficult to dissociate) and competitively inhibits the decomposition of the disaccharide as a substrate.

  As the extraction method, a known method such as a chromatography method can be used. Specific examples of the chromatography method include molecular exclusion chromatography, adsorption chromatography, ion exchange chromatography, affinity chromatography and the like.

The inhibitory action of α-glucosidase activity is described in the method of Kurihara et. al. “Digalactosyldiacyllycerol suppletion of bio9 s9, bio9. Can be evaluated quantitatively.
In this method, yeast α-glucosidase is used as an enzyme, and p-nitrophenyl α-D-glucopyranoside is used as a substrate. Then, p-nitrophenyl α-D-glucopyranoside is added to α-glucosidase in the presence of an α-glucosidase activity inhibitor to produce p-nitrophenyl. The enzyme reaction by α-glucosidase is stopped with sodium carbonate, and the produced p-nitrophenyl is quantified by absorbance at a wavelength of 400 nm, thereby quantifying α-glucosidase activity.

The α-glucosidase activity inhibitor of the present invention can be provided as a drug. Specific examples of the drug include liquids, tablets, granules, capsules, dry syrups and powders.
In addition, α-glucosidase activity inhibitors include vitamins, amino acids, pH adjusters, thickeners, antioxidants, lubricants, binders, surfactants, plasticizers, and additives within a range that does not impair the inhibitory action. You may contain other components, such as a shape agent, a refreshing agent, and a fragrance | flavor.

  The α-glucosidase activity inhibitor is usually administered orally. The dose is usually about 1 mg / kg body weight to 10 g / kg body weight per day, preferably 10 to 1000 mg / kg body weight, although it depends on the age, body weight, and degree of symptoms.

  Furthermore, the α-glucosidase activity inhibitor of the present invention can be provided by being contained in food. Examples of such foods include general foods, beverages, cooking / condiments, taste foods, and functional foods.

  Examples of general foods include cereals such as rice and bread, noodles such as ramen, udon and soba, processed meat products such as ham and sausage, processed fishery products such as kamaboko, chikuwa and hanpen, and dairy products such as butter and powdered milk. Etc. Examples of the beverage include fruit juice, vegetable juice, green tea, barley tea, roasted tea, oolong tea, coffee, tea, carbonated drink, soft drink, sake, wine, shochu, milk, and energy drink. Examples of the cooking / condiment include soy sauce, sauce, mayonnaise, ketchup, sugar, salt, chili oil, vinegar, mustard, and wasabi. In addition, examples of favorite foods include gum, chocolate, cookies, snacks, jellies, gummi, candy, rice crackers, and rice crackers.

  A functional food means a processed food using a component having some physiological action other than nutrition (energy), and is provided as a supplement. The functional food is provided in the form of, for example, a liquid, a granule, a powder, a tablet, a pill, a capsule, a paste, or a film. Moreover, as a functional food, an α-glucosidase activity inhibitor may be contained as a single active ingredient, or other ingredients may be further contained.

  Examples of such other components include vitamins such as vitamin A, vitamin B1, B2, B6, B12, vitamin C, vitamin E, iron, copper, zinc, chromium, magnesium, calcium, sodium, potassium, iodine Minerals such as glycine, alanine, valine, leucine, lysine, asparagine, glutamine, aspartic acid, glutamic acid, tyrosine, phenylalanine and other amino acids, blueberry, cranberry, ginkgo, echinacea, rosehip, cat's claw, maca, valerian, Examples include herbs such as bilberry, turmeric, lutein, and thistle.

Since the α-glucosidase activity inhibitor has an action of inhibiting the decomposition of disaccharides and suppressing an increase in blood glucose level, when ingested, various diseases caused by the increase in blood glucose level such as diabetes, obesity (internal organs) Fatty obesity and abdominal obesity), etc.
In particular, when the α-glucosidase activity inhibitor is Euglena or an extract thereof, the blood glucose level is increased by the α-glucosidase activity inhibitor by including other components derived from Euglena in addition to the component exhibiting the α-glucosidase activity inhibitory activity. The synergistic effect of the suppression of the drug and the medicinal effect by other components can be expected.

  For example, Euglena contains a unique component called paramylon, which is thought to have a cholesterol-extracting action. Therefore, by including paramylon in the α-glucosidase activity inhibitor, in addition to the effect of suppressing the increase in blood glucose level by the α-glucosidase activity inhibitor, it also has an effect of promoting cholesterol excretion by paramylon. Therefore, it is effective in treating, improving, and preventing diseases that cause so-called metabolic syndrome such as diabetes and hypertension.

Hereinafter, the α-glucosidase activity inhibitor of the present invention will be described in detail with reference to specific experimental examples.
1. Example 1: Euglena (light culture)
(Culture / bacteria collection)
Using a KH medium as a medium, Euglena gracilis Z was cultured in a 500 ml shake flask under light irradiation (5000 lux) until reaching a stationary culture phase (1.4 × 10 ⁶ cells / ml). 100 ml of the obtained culture broth was centrifuged at 3000 rpm for 10 minutes with a cooling centrifuge (Hitachi CF7D2), and Euglena cells were collected.
After freeze-drying for 24 hours at 0.1 torr using a lyophilizer (Tokyo Rika FD-5N), total lipids were extracted by the Bligh & Dyer method using a chloroform / methanol mixture. From 450 mg of the total lipid obtained, lipids were fractionated by silica gel column chromatography shown below.

(Total lipid extraction / fractionation)
A glass open column of 25 × 350 mm was packed with 15 g of silica gel for column chromatography (Nacalai) suspended in chloroform. Next, 450 mg of total lipid dissolved in chloroform was applied to a silica gel packed column, and 300 ml of chloroform, 600 ml of acetone and 300 ml of methanol were spontaneously dropped in this order at room temperature to extract the total lipid. Of the fractions after extraction, it was confirmed that the chloroform fraction contained neutral lipids, the acetone fraction contained glycolipids, and the methanol fraction contained phospholipids.
As a result of measuring the weight of each lipid, it was 150 mg of neutral lipid, 200 mg of glycolipid, and 95 mg of phospholipid.

(Glycolipid fractionation)
20 mg of each of these lipid fractions was heated in 1 ml of 10% hydrogen chloride methanol at 80 ° C. for 3 hours. After allowing to cool, 6 ml of ion-exchanged water was added, 1 ml of hexane was further added to extract fatty acid methyl ester, and the fatty acid composition was measured by gas chromatography (GC-2014 manufactured by Shimadzu). Furthermore, the glycolipid fraction was fractionated by silica gel chromatography as shown below.

The same silica gel 20 g was packed in the column used for the total lipid extraction / fractionation described above. Next, 100 mg of glycolipid was dissolved in a mixed solvent of chloroform (C) / methanol (M) / water (W) (C: M: W (volume ratio) = 90: 10: 0.5). With the column cock fully open, 200 ml of a mixed solvent in which glycolipids were dissolved was passed through the column. Subsequently, 200 ml of a mixed solvent in which glycolipids are not dissolved (C: M: W = 80: 20: 2) and a mixed solvent in which glycolipids are not dissolved (C: M: W = 70: 30: 3) are also dissolved. ) 200 ml was passed through the column in this order to extract glycolipids. It was confirmed that the glycolipid was extracted from the column in the order of monogalactosyl diacylglycerol (MGDG), digalactosyl diacylglycerol (DGDG), and sulfoquinovosyl diacylglycerol (SQDG).
As a result of measuring the weight of each glycolipid, they were DGDG 45 mg, MGDG 53 mg, and SQDG 48 mg.

2. Example 2: Euglena (dark culture)
Lipids were fractionated under the same conditions as in Example 1 except that Euglena was cultured in the dark (stationary culture period: 1.4 × 10 ⁶ cells / ml). As a result, 190 mg of neutral lipid, 60 mg of glycolipid, and 139 mg of phospholipid were obtained. Furthermore, the glycolipid fraction was fractionated under the same conditions as in Example 1 to obtain DGDG 55 mg, MGDG 43 mg, and SQDG 38 mg.

3. Example 3: Chlorella (light culture)
Lipids were fractionated under the same conditions as in Example 1 except that chlorella (Chlorella vulgaris C-30 (OD ₆₆₀ = 16)) was brightly cultured instead of Euglena. As a result, 90 mg of neutral lipid, 230 mg of glycolipid, and 125 mg of phospholipid were obtained. Furthermore, the glycolipid fraction was fractionated under the same conditions as in Example 1 to obtain DGDG 52 mg, MGDG 43 mg, and SQDG 48 mg.

4). α-Glucosidase activity measurement Each lipid (neutral lipid, glycolipid, phospholipid, MGDG, DGDG, SQDG) fractionated by the above procedure was dissolved in ethanol to a concentration of 1 mg / ml. 0.1 ml of ethanol solution of each lipid was dispensed into each test tube, and 0.1 ml of 20 mM p-nitrophenyl α-D-glucopyranoside solution and 10 mM phosphate buffer (pH 7.0) 2 2 ml, and kept warm for 5 minutes in a 37 ° C. water bath. Next, 0.1 ml of a yeast-derived α-glucosidase solution (70 units / mg manufactured by Wako Pure Chemical Industries, Ltd.) 0.1 ml (5 μg / ml) was placed in each test tube and reacted at 37 ° C. for 2 minutes.

Subsequently, 1.5 ml of a 0.25M sodium carbonate solution was put into a test tube to stop the reaction, and the absorbance at 400 nm was measured with a spectrophotometer (manufactured by JASCO V-530). The inhibition rate (%) of α-glucosidase activity was calculated.
In addition, the test tube which added distilled water instead of the enzyme solution as a blank and the test tube which added ethanol instead of the lipid solution as a control were prepared, and the absorbance measurement was performed similarly to the above.
Inhibition rate (%) = {1− (Asam−Abl) / (Csam−Cbl)} × 100
(Asam: absorbance after reaction (sample addition), Abl: absorbance after reaction (sample addition-blank), Csam: absorbance after reaction (no sample), Cbl: absorbance after reaction (no sample-blank))

5). Evaluation of α-glucosidase activity inhibitory activity Using the sample after total lipid fractionation, the inhibition rate for each type of lipid (neutral lipid, glycolipid, phospholipid) was calculated, and α-glucosidase activity inhibitory activity for each lipid Evaluated. The results are shown in Table 1.

  As can be seen from this table, in any of Examples 1 to 3, the neutral lipid showed no α-glucosidase activity inhibitory action. Moreover, the alpha-glucosidase activity inhibitory effect was seen slightly about the phospholipid. It was found that glycolipid exhibits a very strong α-glucosidase activity inhibitory action.

  Further, when Example 1 and Example 2 were compared, the inhibition rate of α-glucosidase activity by glycolipids was more than 5 times higher when Euglena was cultured lightly than when darkly cultured. Therefore, it was found that the α-glucosidase activity inhibitory action of Euglena extract was stronger when cultured under light irradiation.

  Further, comparing Example 1 and Example 3, the inhibition rate of α-glucosidase activity by glycolipid is about 1.4 times higher in Example 1 (Euglena) than in Example 3 (Chlorella). I understood. This indicates that Euglena glycolipids have stronger α-glucosidase activity inhibitory action than chlorella glycolipids.

Next, using the samples obtained by further fractionating the glycolipids of Example 1 (Euglena light culture) and Example 3 (Chlorella light culture) (Examples 1-2 and 3-2, respectively), glycolipids were used. The inhibition rate of α-glucosidase activity for each (MGDG, DGDG, SQDG) was calculated, and the α-glucosidase activity inhibitory action was evaluated for each glycolipid. The results are shown in Table 2.

  As can be seen from this table, in both Euglena and Chlorella, MGDG and DGDG have a low inhibition rate of α-glucosidase activity, whereas SQDG has a inhibition rate about 4 times higher than that of MGDG and DGDG. It was. From this, it was found that SQDG is the main active ingredient having an α-glucosidase activity inhibitory action in glycolipids. On the other hand, it was found that MGDG and DGDG also have an α-glucosidase activity inhibitory action, although weaker than SQDG.

  In addition, the inhibition rate of α-glucosidase activity was slightly higher in Euglena-derived SQDG than in Chlorella-derived SQDG. Although the reason for this is not clear, it is considered that one of the causes is that there is a difference in the molecular structure of SQDG between Chlorella and Euglena. As a reason why such a difference in molecular structure occurs, it is considered that the fatty acid composition of SQDG differs between chlorella and Euglena.

Claims (6)

  The alpha-glucosidase activity inhibitor characterized by containing a unicellular eukaryotic algae or its extract.   The α-glucosidase activity inhibitor, wherein the unicellular eukaryotic algae is Euglena or Chlorella.   The α-glucosidase activity inhibitor according to claim 1, wherein the unicellular eukaryotic algae is obtained by culturing under light irradiation.   The α-glucosidase activity inhibitor according to claim 1, wherein the extract is extracted with a lipophilic solvent.   The α-glucosidase activity inhibitor according to claim 1, wherein the extract contains a glycolipid.   The foodstuff characterized by including the alpha-glucosidase activity inhibitor of any one of Claims 1-5.