JPS6328885B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an antidiabetic agent, and an object of the present invention is to provide a novel antidiabetic agent having excellent antidiabetic and therapeutic effects. Another object of the present invention is to provide a novel antidiabetic agent that exhibits antidiabetic effects even when administered orally. The present inventor has been searching for substances with anti-diabetic effects for many years, and as a result of screening a large number of substances, it was found that oleanolic acid represented by the structural formula below has excellent anti-diabetic effects. The present invention was completed based on the discovery that this effect can also be exerted by oral administration. That is, the present invention has the following formula: The present invention relates to an antidiabetic agent containing oleanolic acid as an active ingredient. Oleanolic acid shown by the above structural formula is a known substance and can be extracted from plants such as Oleander and can also be obtained from the acid hydrolyzate of sugar beet. It has been reported that Mr. Satoshi et al. extracted it from this drug (Japanese oleander), and in 1947, Mr. Morizo Ishidate et al. reported that it was extracted from Oleander (Oleander from Honshu). The present inventor has also discovered that it can be extracted from mountain mushroom. That is, oleanolic acid represented by the above structural formula is obtained by adding this drug, oleander, wild ash, etc., to a non-hydrophilic organic solvent such as lower fatty acid ethers, lower halogen alkanes, lower fatty acid esters, benzenes, or other petroleum-based solvents. Cold soaking or digestion, and the use of column chromatography using an adsorbent such as alumina, silica gel, or phlorizin for the extract;
It can be easily separated by purification by applying a recrystallization method. The properties of the oleanolic acid shown by the above structural formula to be separated are as follows. Melting point: 294-295°C. [a] ²⁰ _D +83.3° (C = 0.6 chloroform). Colorless fine powder crystals. IR (KBr) cm ^-1 : r _OH 3450, r _COOH 1695 R value of thin layer chromatography; Silica gel G, developing solvent chloroform: methanol (20:1), R value 0.45 Next, as shown in the above structural formula Showing the pharmacological effects of oleanolic acid. [1] Diabetes preventive effect experimental method: A group of 8 male Wistar rats weighing around 180 g were fasted for 48 hours, then streptodotocin 50 mg/Kg was intravenously injected, and the test drug was administered 1 hour after the injection. Orally administered twice a day for a total of 6 times for 3 days. At the same time as the fifth administration, the animal is placed in a metabolic gauge to measure water absorption and urine output, and blood is collected under ether anesthesia 4 hours after the sixth administration. The test items were measurement of body weight gain, water absorption, urine volume, blood sugar level, urine sugar level, and urine hexosamine level for each rat from the start of the experiment to the end of the experiment. The results are shown in Table 1. Table 1 lists as control groups those not treated with streptodotocin and those treated only with streptodotocin. The oleanolic acid represented by the above structural formula was obtained from Production Example 1 and is abbreviated as "product of the present invention" in the table. -The same applies to each table below. −.

[Table] ** Elson-Morgan method *** Consideration of administration as a 1% suspension of gum arabic; As is clear from the above table, the product of the present invention clearly suppresses the onset of diseases specific to diabetes, In particular, when administered at 500 mg/Kg, the blood sugar level was approximately 1/2 that of the control.
The urine sugar level has decreased by about 1/3, showing a clear trend of improvement. [2] Experimental method for antidiabetic action: A group of 8 male Wistar rats weighing around 180 g were fasted for 48 hours, then streptodotocin 50 mg/Kg was intravenously injected, and the test drug was administered after 3 weeks. Administer once orally. Blood sugar levels were measured before and every hour after oral administration. The results are shown in Table 2. Table 2 lists, as control groups, those not treated with streptodotocin and those treated only with streptodotocin. In addition, for comparison, the case where ``insulin'' was used as a test drug by intravenous injection is also listed.

[Table] *Glucose-oxidase method
** Consideration of administration as a 1% suspension of gum arabic; As is clear from the above table, oral administration of the product of the present invention showed a remarkable hypoglycemic effect on diabetic rats, and its strength was Invention product 250
The dose of insulin 3 units/Kg was almost the same as when administered mg/Kg, indicating that the product of the present invention exerts a therapeutic effect on diabetes. In the experiment [1], water and food were provided ad libitum, and in the experiment [2], neither water nor food was provided during the experiment. [3] Acute toxicity experimental method: Groups of 10 DD male mice weighing around 19 g were used, and the number of deaths was determined from the number of deaths within 3 days after oral administration of the test drug.
Asked for _LD50 . The results are shown in Table 3.

[Table] * Consideration of administration as a 1% suspension of gum arabic; As is clear from the table above, there were no fatalities at all even with administration of 3000 mg/Kg, and therefore oleanolic acid shown by the above structural formula is acutely toxic. It turns out that it is very weak. In addition, the observation period (3 days) in the experiment [3]
Water and food, including food, were provided ad libitum. [4] Dosage and administration method As is clear from the above experiments, oleanolic acid represented by the above structural formula can exhibit antidiabetic effects by oral administration. Considering the results of the above experiments, the dosage for use in the treatment of adults is 500 mg to 250 mg at a time.
It is estimated that it is effective when taken 2 to 3 times a day. For administration, it is preferably provided in a form suitable for absorption from the gastrointestinal tract. Next, production examples and formulation examples of oleanolic acid represented by the above structural formula will be given. Production Example 1 3 kg of wild radish was digested 3 times using ethyl acetate 5, the extract was concentrated to obtain an extract, and dried under reduced pressure to obtain 83 g of dry extract (yield: 4
%). Using 83g of this dried extract and 8kg of silica gel,
Next, perform column chromatography using benzene and chloroform:methanol (100:1) as a developing agent, while also using thin layer chromatography (silica gel G, using chloroform:methanol (20:1) as a developing solvent). carry out separation,
A component showing an R value of 0.45 on thin layer chromatography was separated, and the solvent was distilled off to obtain colorless powder crystals.
This was recrystallized from ethanol to obtain 9.5 g of pure product (yield 0.35%). This product has the following structural formula: Melting point: 305° to 307°C Elemental analysis value: C ₃₀ H ₄₈ O ₃ Theoretical value (%) C: 78.90 H: 10.59 Experimental value (%) C: 78.85 H: 10.59 It was confirmed that it was the oleanolic acid shown. Production example 2 1 kg of this drug was digested 3 times using ether 3,
Concentrate the extract to obtain an extract, and dry under reduced pressure to obtain 58 g of dry extract (yield 5.8%). Using 58g of this dried extract and 6kg of silica gel,
Next, perform column chromatography using benzene and chloroform:methanol (100:1) as a developing agent, while also using thin layer chromatography (silica gel G, using chloroform:methanol (20:1) as a developing solvent). carry out separation,
A component showing an R value of 0.45 on thin layer chromatography was separated, and the solvent was distilled off to give 22 g of green-white powder (yield:
2.2%) was recrystallized from ethanol to obtain 19.5 g of pure product (yield 1.95%). This product has the following structural formula: Melting point: 305° to 307°C Elemental analysis value: C ₃₀ H ₄₈ O ₃ Theoretical value (%) C: 78.89 H: 10.59 Experimental value (%) C: 78.88 H: 10.59 It was confirmed that it was the oleanolic acid shown. Production Example 3 1 kg of dried leaves of oleander is digested three times with ethyl acetate 3, and the extract is concentrated to obtain an extract, which is dried under reduced pressure to obtain 65 g of dry extract (yield 6.5%). Using 65g of this dried extract and 6kg of silica gel,
Next, perform column chromatography using benzene and chloroform:methanol (100:1) as a developing agent, while also using thin layer chromatography (silica gel G, using chloroform:methanol (20:1) as a developing solvent). carry out separation,
A component showing an R value of 0.45 on thin layer chromatography was separated, and the solvent was distilled off to give 18 g of green-white powder (yield:
1.8%) was recrystallized from ethanol to obtain 10.0 g of pure product (yield 1.0%). This product has the following structural formula: Melting point: 305° to 308°C Elemental analysis value: C ₃₀ H ₄₈ O ₃ Theoretical value (%) C: 78.90 H: 10.59 Experimental value (%) C: 78.80 H: 10.58 It was confirmed that the substance is the one indicated. Formulation Example Tablets 1. Oleanolic acid: 250 mg 2. Mannitrate: 200 ml (excipient) 3. Potato starch: 47 mg (excipient) 4. Magnesium stearate 8 g (lubricant) Mix 1 and 2 above and add water. The mixture is added and kneaded, and then the above 3 is added and granulated. Next, add this particle to No.
After passing through a No. 60 mesh (BS) sieve, drying, and passing through a No. 16 mesh (BS) sieve,
Mix with 4 above and compress with a 7/16″ punch to yield 500 tablets each.
mg tablet. Note that this tablet can also be coated with a conventional easily soluble film coating, if necessary. According to the present invention as described above, it is possible to provide a novel antidiabetic agent that exhibits excellent antidiabetic effects when administered orally, and its manufacturing cost is relatively low compared to that of insulin. This is advantageous because it is relatively inexpensive due to its different properties, and especially when acid hydrolyzate of sugar beet is used as a raw material, waste products other than sugar can be used as a raw material.

Claims (1)

[Claims] 1 formula An antidiabetic agent containing oleanolic acid as an active ingredient.