JPH0816057B2 - Glycation inhibitors - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pharmaceutical product containing ascochlorin represented by the general formula (I) and its derivatives as one or more active ingredients. More specifically, it relates to a therapeutic agent for diabetic complications by inhibiting glycation, especially diabetic neuropathy, diabetic nephropathy, and diabetic retinopathy.

[0002]

2. Description of the Related Art Although diabetic complications are not characteristic of diabetes, high rates of macroangiopathies and microangiopathies characteristic of diabetes, namely diabetic nephropathy,
It is roughly divided into diabetic retinopathy and diabetic neuropathy. It is said that diabetes is not a scary disease unless complications occur, and the severity of diabetes cannot be expressed by the easily fluctuating blood sugar level. Sakamoto asked, "Is it possible to prevent the development of diabetic complications by controlling blood sugar?"
"It is unlikely that hyperglycemia will continue to play a critical role in all processes from the onset of complications to the progression to a dire final picture," Nobuo Sakamoto, "Diabetes", 3
3, 633, 1990). Currently, the countermeasure against diabetic complications is the most important issue in diabetes treatment, and development of a preventive / therapeutic drug for diabetic complications is expected.

With regard to the onset of diabetic complications, it is considered that various factors are involved in a complicated manner on the basis of metabolic abnormality based on hyperglycemia, and among these factors, particularly regarding microangiopathies, polyol metabolism is involved. And glycation is said to be important. Regarding polyol metabolism, it is said that its aldose reductase is activated under hyperglycemia and sorbitol accumulates in tissues and plays an important role in the development of diabetic neuropathy.Elaptat is an aldose reductase inhibitor. Are known.
However, no effective therapeutic agent has been developed for glycation inhibitors.

Glycation is also called Maillard reaction, and glycated proteins that have undergone glycation are considered to be one of the causes of renal basement membrane thickening. Accumulation of glycated proteins in the nucleus and capsule of the lens is important for diabetic cataract. Is considered to be a factor. Glication produces a Schiff base by a non-enzymatic binding reaction between a protein and a reducing sugar, which undergoes Amadori rearrangement to produce a ketoamine. The reaction so far is considered to be the initial stage of the Maillard reaction. This Amadori compound slowly undergoes dehydration and rearrangement reactions to move to the latter stage of the Maillard reaction. Furosine is known as an acid hydrolyzate of an early stage compound. Furosine has been reported to significantly increase the tissue content of sciatic nerve, kidney, tendon, lens and the like in diabetic patients and experimental diabetic model animals (Voglt Diabetes,
31, 1123, 1982, Shogo Masuda, "Diabetes", 3
4, 576, 1991).

[0005]

As described above, glycation inhibitors are considered to be useful as preventive and therapeutic agents for diabetic complications, but no effective glycation inhibitors have been developed so far. It was

The present invention inhibits glycation and reduces the accumulation of glycated protein in tissues, and is useful for the prevention and treatment of diabetic complications, specifically diabetic neuropathy, diabetic nephropathy, and diabetic retinopathy. It is what

[0007]

The present invention relates to a glycation inhibitor of an ascochlorin derivative represented by the general formula (I).

[0008]

Embedded image [Wherein R represents a hydrogen atom or a _{- (C n H 2n) -R} '(n is 1
To an integer of 5, R'represents a hydrogen atom or a group -COOR ", and R" represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.]]

Ascochlorin is an antibiotic discovered by the present inventors from the product of the filamentous fungus Ascochyta visiae (see Japanese Patent No. 585252). Regarding the derivative thereof, the manufacturing method and the blood glucose lowering action are disclosed in Japanese Patent Publication No. 1-41624 and Japanese Patent Publication No. 3-6.
No. 138. The present inventor has investigated the inhibitory action of glycation, which is deeply involved in diabetic complications, independently of hyperglycemia, with respect to ascochlorin and its derivatives. The excellent glycation inhibitory action of the compound shown in (4) was discovered in in vivo and in vitro experiments.

The compounds represented by the general formula (I) are specifically the following compounds.

[0011]

Embedded image To investigate the effect of these ascochlorins of the present invention and their derivatives on the formation of the glycation reactant ketoamine, the acid hydrolysis product furosine, in vitro.
As an experiment, ascochlorin and its derivatives were added to a reaction solution of bovine serum albumin and glucose and cultured for a long time to examine the effect on furosine production.
As an n vivo experiment, streptozotocin diabetic rats were administered with the ascochlorin derivative 4-O-carboxymethylascochlorin (AS-6) for 1 month to examine the effect of AS-6 on the production of furosine in each tissue.
As a result, AS-6 is in vivo and in vitro.
In both the experiments, the production of furosine was suppressed, and AS-6 was found to have a glycation reaction inhibitory action. This is expected to prevent and treat AS-6 against diabetic complications such as diabetic neuropathy, diabetic nephropathy and diabetic retinopathy.

[0012] As a result of oral administration of 4-0-methylascochlorin to diabetic patients with diabetic complications for 12 weeks, diabetic nephropathy and diabetic neuropathy were remarkably improved.

The dose of the medicament of the present invention varies depending on the type of disease state, symptoms and the like, but for example, in the case of injection, it is 5 to 100 mg per adult per day, and in the case of oral administration, it is 30 to 3000.
In the case of suppositories, the target can be achieved with 50 to 1000 mg. The compound of the present invention may be used alone,
Usually, it is preferably neutralized with an alkali to be dissolved in water, or mixed with a suspension, an excipient or other auxiliary agent to prepare a dosage form suitable for parenteral administration and oral administration. Preferred formulations include, for example, injections, powders, granules, tablets, dragees, pills, capsules, suppositories and the like.
These preparations are prepared by a conventional method, for example, as an excipient or an adjuvant, lactose, sucrose, various starches, glucose, cellulose, methyl cellulose, carboxymethyl cellulose,
Magnesium stearate, lauryl sulfate, talc,
It is produced using vegetable oil, lecithin and a mixture of two or more of these.

[0014]

Example: The amount of furosine was 0.1 ml in 0.4 ml serum.
40% trichloroacetic acid was added and centrifuged, and then the precipitate was washed twice with 2 ml of 8% trichloroacetic acid.
Hydrolysis was performed at 30 ° C. for 30 hours. The tissue is chloroform-
After homogenizing with a mixture of methanol and removing the extract,
6N hydrochloric acid was added and reacted at 95 ° C. for 30 hours, and 10 to 20 μl of the reaction solution was injected into high performance liquid chromatography. High performance liquid chromatography is Tosoh HLC-80
3D, ODS-80T (Tosoh) was used for the column. 7
When measured with 280 nm at a flow rate of 1 ml / min using mM phosphoric acid as a solvent, furosine was detected at 2.7 minutes after the injection, and the amount of furosine was expressed by its area (Morada Tadashi, Diabetes, 28,
1119, 1985).

Examples of the present invention will be shown below, but the present invention is not limited to these examples.

Example 1 400 mM glucose was added to 25 mg / ml bovine serum albumin, and ascochlorin and its derivatives were added at a ratio of 1.2 mg / ml.
After culturing at 10 ° C for 10 days, the produced furosine was measured by high performance liquid chromatography. The results are shown in Table 1.

[0017]

[Table 1] As shown in Table 1, ascochlorin and its derivatives significantly suppressed the production of furosine.

[Example 2] 400 mM glucose was added to 25 mg / ml bovine serum albumin, and AS-6 was added to DMSO.
1 mg / ml was added to the solution, the mixture was cultured at 37 ° C. for 5 and 10 days, and the produced furosine was measured by high performance liquid chromatography. The results are shown in Table 2.

[0019]

[Table 2] As shown in Table 2, AS-6 significantly suppressed the production of furosine.

Example 3 400 mM glucose was added to 25 mg / ml bovine serum albumin, and AS-6 was added to DMSO.
Dissolved in 0.1, 0.4, 1.6mg / ml, 37 ℃
The resulting furosine was measured by high performance liquid chromatography. The results are shown in Table 3.

[0021]

[Table 3] As shown in Table 3, the results are AS on both 7th and 14th days.
Furocin production was significantly suppressed at a concentration of -6, 0.4 mg / ml or more.

Example 4 Streptozotocin (STZ) was intravenously administered to Wistar rats at 55 mg / kg, and at the same time, 0.1% AS-6 mixed feed was fed for one month to raise furosine in blood and tissues. Was measured. The results are shown in Table 4.

[0023]

[Table 4] As shown in Table 4, the blood glucose level of the STZ-administered control group was 5.1 times higher than that of the normal control group, but the blood glucose level was decreased by 19% and the fructosamine level was 6 by AS-6 administration.
It increased by 6% but decreased by 16% by AS-6 administration.
The blood furosine concentration in the STZ-administered control group was 2.7 times higher than that in the normal control group, but 22% lower by AS-6 administration. The amount of furosine in the sciatic nerve and kidney in the STZ-administered control group increased 6.7 times and 4.6 times, respectively, compared to the normal control group, but were 23% and 3 respectively by AS-6 administration.
It decreased by 1%.

[Example 5] 120 mg of 4-0-methylascochlorin was taken 3 times after each meal, and 16 diabetic patients (of which there were subjective symptoms of neurosis (neuralgia, hypoesthesia, etc.): 12 people,
There was no subjective symptom: 4 subjects were administered for 12 weeks, and the improving effect on neurosis was examined. The results are shown in Table 5.

[0025]

[Table 5] Administration of 4-0-methylascochlorin improved the subjective symptoms of neurosis over time, and the number of "symptomatic" decreased from 12 to 2 after 12 weeks.

Example 6 120 mg of 4-0-methylascochlorin was administered 3 times after each meal to 30 diabetic patients for 12 weeks, and biochemical examination of urine was performed to examine the improving effect on nephropathy. The results are shown in Table 6.

[0027]

[Table 6] Administration of 4-0-methylascochlorin for 12 weeks significantly improved nephropathy.

[0028]

The compound represented by the general formula (I) is
Since it exhibits an excellent glycation reaction inhibitory action, it is useful as a preventive or therapeutic drug for diabetic complications such as diabetic neuropathy, diabetic nephropathy and diabetic retinopathy.

Claims (2)

[Claims] 1. A compound of the general formula (I) [Wherein R represents a hydrogen atom or a _{- (C n H 2n) -R} '(n is 1
Is an integer of 5 to 5, R'represents a hydrogen atom or a group -COOR ", and R" represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.] A glycation inhibitor containing one or more active ingredients. 2. The glycation inhibitor according to claim 1, which is for preventing and treating a disease selected from the group of diabetic neuropathy, diabetic nephropathy and diabetic retinopathy.