JP2541723B2 - Novel salicylic acid-maltol complex - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel salicylic acid-maltol complexes of formula I and processes for making I.

(In the formula, R represents H, an alkyl group containing 1 to 5 carbon atoms or an alkanoyl group containing 1 to 5 carbon atoms. R ₁ is H or 1 to 5 carbon atoms. Represents an alkyl group containing) acetylsalicylic acid (aspirin), antipyretic, analgesic,
Shows antioxidant and antithrombin activity. However, it induces gastric ulcer.

Maltol derivative II is a component of Panax ginseng and their structures are:

(Wherein R ₁ is as defined above) Maltol derivatives are known to exhibit antioxidant activity. Salicylic acid has been used as a keratolytic agent and food preservative.

The present invention is based on the observation that the novel maltitol ester of salicylic acid derivative does not exhibit salicylic acid ester-induced gastric ulcer forming activity, while showing higher antioxidant activity and antithrombin activity than salicylic acid derivative.

The object of the invention presented here is therefore to provide novel compounds of the formula I which exhibit the abovementioned pharmacological activities and exhibit few side effects.

The present invention also provides a synthetic method of compound I. Compounds of formula I include maltol derivative II and salicylic acid derivatives
It is produced by the esterification of III as follows.

Where R and R ₁ are as described above and M is -H or an alkali metal. The esterification of II with III includes alkyl halides such as chloroform, methylene chloride and ethylene chloride, formamide and acetamide. In the presence of an amide such as, an ether such as tetrahydrofuran and dioxane, or other organic solvent.

It is desirable to activate the carboxyl group of III.
Activation can be accomplished by treating III with a halogenating agent to produce an acid halide, or by other well known methods used in organic synthesis.

The reaction of II with III containing a carboxyl group can be carried out in the presence of a diamine such as N, N-dicyclohexylcarbodiimide, or other esterifying agent used in organic synthesis.

If the free acid is obtained upon activation of the carboxyl group, esterification should be carried out in the presence of a tertiary amine or alkali to remove the free acid.

The reaction proceeds at a temperature from 0 ° C. to the boiling point of the solvent used. The reaction is usually complete within 30 minutes to 48 hours.

The invention will now be illustrated by the following examples and tests.

Example 1 Acetylsalicylic acid (18.0 g, 0.10 mol), maltol (12.6 g, 0.10 mol) and N, N-dicyclohexylcarbodiimide (22.7 g, 0.11 mol) were added to methylene chloride 1
It was dissolved in 00 ml and the solution was stirred for 6 hours at room temperature.

After removing N, N-dicyclohexylurea by filtration, the filtrate was washed successively with water, 5% acetic acid and water. The solution was then dried over Na ₂ SO ₄ . After filtration and concentration, needle crystals of maltol-acetylsalicylic acid ester (Compound A) were obtained in n-hexane / ethanol (1: 3). The NMR spectrum is shown in FIG.

mp: about 105 ° C MS [m / z]: 288 (M ⁺ ), 246 (C ₁₃ H ₁₀ O ₅ ), 121 (C ₇ H ₅ O ₂ ) ¹ H NMR (CDC1 ₃ ) [δ ppm]: 8.21 (1H, dd, J = 1.9,7.
7), 8.07 (1H, d, J = 5.7), 7.74 (1H, dt, J = 1.9,7.7),
7.43 (1H, dt, J = 1.3,7.7), 7.24 (1H, dd, J = 1.3,7.7),
6.48 (1H, d, J = 5.6), 2.32 (3H, s), 2.25 (3H, s) Example 2 According to the method of Example 1, maltol-salicylic acid ester was obtained. The NMR spectrum is shown in FIG.

mp: Approx. 99 ° C. Example 3 Enzymatic production method of maltole-salicylic acid ester Acetone powder (1.8 g) of rat liver was suspended in 50 ml of 0.1 M phosphate buffer (pH 7.4) and stirred at 4 ° C. for 12 hours. The resulting suspension was centrifuged at 8,000 rpm for 5 minutes. 10 ml of the supernatant thus obtained contained 10% Tweezers containing maltol-acetylsalicylic acid ester.
30 ml of n-30 solution was added. The mixture was incubated at 37 ° C. for 1 hour and extracted twice with 30 ml CHC1 ₃ . The extract was then added and concentrated to dryness. The dried residue was dissolved in 5 ml of methanol and left at 4 ° C. After filtration, 200 mg of maltole-salicylic acid ester was obtained as needle crystals. The NMR spectrum was equal to that obtained in Example 2.

Test 1 Measurement of antioxidant activity Animal: Male ICR mouse, body weight 20-25g Sample: Compound A Criteria: 1. Maltol (10% DMF saline) 2. Aspirin (10% DMF saline) TBA reagent: thiobarbituric acid (0.3% ) And SDS (0.4
%) Dissolved in 7.5% acetate buffer (pH 4.0) Experimental procedure: The antioxidant activity was determined by the method of Okawa et al. (Biochemistry (Japa
n) (1977), 49 (8), (829). Mouse liver was homogenously dispersed in 10 volumes of saline. 10 ml of the sample solution was added to 10 ml of the homogenate, and the mixture was incubated at 37 ° C for 3 hours. 36 ml of TBA reagent was then added to the mixture and the resulting mixture was heated at 98 ° C for 1 hour. Temperature 24
After lowering to ℃, the reaction mixture was extracted with 2 ml of butanol and the butanol phase was centrifuged. Butanol phase 532n
The absorbance at m was measured. The results are shown in Table I. Compound A showed antioxidant activity at concentrations above 2.5 x 10M.

Test 2 Measurement of antipyreticity Animal: Male ICR mouse, body weight 17 to 21 g (5 animals in 1 group) Sample: Compound A (160 mg / kg, 500 mg / kg in 1% CMC) Reference: Aspirin (1% CMC Pyrogen: typhoid fever vaccine (0.1 ml / mouse, intraperitoneal) Experimental procedure: Winter et al. Method (Winter, CA et al. (1963), J.Pharmaco)
l.Exptl.Therap., 141, 369) with some modifications to determine antipyretic properties. Rectal temperature was measured at hourly intervals with a digitized thermometer inserted at a depth of 3 cm. At time zero, mice were injected ip with typhoid fever vaccine. Two hours later, mice were orally dosed with aspirin and the sample (compound of Example 1).

As shown in FIG. 3, the antipyretic power of compound A was 5 times lower than that of aspirin.

Test 3 A. Measurement of anti-inflammatory activity by carrageenin-induced edema test Animal: Male Sprague Dawley rat, body weight about 170g
(Group of 5 animals) Sample: Compound A (300 mg / kg, 450 mg / kg in 1% CMC) Reference: Phenylbutazone (100 mg / kg in 1% CMC) Administration method: Oral administration Experimental procedure: Winster et al. Method (Winter, CA, Risley, EAand Nus
s, GW (1963), J.Pharmacol.Exptl.Therap., 141,369)
The inhibitory effect of carrageenin-induced edema by compound A and aspirin was determined according to Samples were administered orally 6 hours and 30 minutes prior to carrageenan injection. Edema was induced by subcutaneously injecting 0.05 ml of 1% carrageenin in saline into the hind paws of rats. The edema volume was then measured at timed intervals. The results are shown in Table II. Compound A is 30
It was determined to have no anti-inflammatory effect when used in amounts of 0 mg / kg and 450 mg / kg.

B. Measurement of protein stabilizing activity Sample: Compound A (1 x 10 ^-3 M in 5% DMF solution) Experimental procedure: As described by Mizushima (Mizushima, Y. (196
5), Lancet, 1, 169), and analyzed the protein stabilizing activity of the sample. 0.75% BSA in 0.1M phosphate buffered saline (pH 5.3)
2 ml was briefly mixed with 1 ml of the appropriately diluted test sample solution. After standing at room temperature for 15 minutes, the reaction mixture
Incubated at 0 ° C and 0 ° C for 3 minutes and 15 minutes, respectively.
The degree of heat denaturation of BSA was evaluated by the turbidity of the colloidal precipitate, and the absorbance of this precipitate at 570 nm was measured. The results showed that Compound A did not contain protein stabilizing activity (data not shown).

C. Measurement of antithrombin activity Animal: Male Sprague Dawley rat, weight 180-250
g Sample: Compound A, in 5% DMF solution (1 × 10 ⁻³ M) Experimental procedure: Rats were anesthetized with ether and 9 volumes of blood were collected by cardiac puncture with 1 volume of 3.12% sodium citrate. did. The combined blood samples were centrifuged at 1200 rpm at 4 ° C for 20 minutes to obtain platelet-rich plasma. Four
After centrifugation for 10 minutes at 3,000 rpm at ℃, the resulting precipitate (platelets) 0.01M phosphate buffered saline (pH 7.
It was resuspended in 1). 0.1 ml of the sample solution was added to 1 ml of this solution. After incubating at 37 ° C for 30 minutes, 10 units of thrombin was added and the reaction mixture was incubated for 1 hour. As a result of visually observing platelet aggregates, Compound A (1 × 10 ⁻³ M) exhibited antithrombin activity.

Test 4 Gastric ulceration test Animal: Male Sprague Dawley rat, body weight 160-210
g (6 animals in 1 group) Sample: Compound A (100 mg / kg, 200 mg / kg, 800 in 1% CMC)
Reference: Aspirin (200 mg / kg in 1% CMC) Administration: Oral Experimental procedure: Murakami et al. (Murakami, M. et al. (1982), Japan J.
Pharmacol., 32, 299), gastric ulceration experiments were performed. Rats were left without food for 24 hours and only water ad libitum (water was removed 2 hours before the experiment). The sample suspended in a 1% CMC solution was removed. Then, the stomach was inflated by injecting 10 ml of 2% formalin through the cardia, and immersed in 2% formalin for 10 minutes. Then, the stomach was incised along the greater curvature and the length of each lesion in the gland was measured. The total length (mm) of all lesions per rat was used as the ulcer index. The results are shown in Table III.

Numbers in parentheses indicate the number of rats with gastric ulcer.

The results showed that Compound A did not cause gastric ulcer at 5 times the amount of aspirin.

Test 5 Measurement of bleeding time Experimental groups were administered with equal amounts of Compound A and aspirin separately for 10 days.

As shown in Table IV, Compound A prolonged bleeding time by 50%.

Test 6 Acute toxicity test When administered orally, Compound A showed almost no toxicity in mice (LD ₅₀ = 2.14 g / kg).

In conclusion, the compounds according to the invention showed antioxidant activity at concentrations above 2.5 × 10 ⁻⁴ M and an equivalent antipyretic activity in a 5-fold amount compared to aspirin.

On the other hand, Compound A showed few side effects, as it did not cause gastric ulceration. On the other hand, aspirin caused ulceration in a 4-fold lower amount.

Therefore, the compound described in the present invention is a novel acetylsalicylic acid ester derivative that maintains the antioxidant activity of the maltol derivative and exhibits antipyretic and anti-inflammatory activities.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows maltole-acetylsalicylic acid ester.
It is a figure which shows an NMR spectrum.

FIG. 2 is a diagram showing an NMR spectrum of maltole-salicylic acid ester.

FIG. 3 shows the antipyretic effect of the compound described in Example 1.

Claims (3)

(57) [Claims] 1. The following formula I (In the formula, R represents H, an alkyl group containing 1 to 5 carbon atoms or an alkanoyl group containing 1 to 5 carbon atoms, and R ₁ is H or 1 to 5 carbon atoms. Represents an alkyl group containing a). 2. Formula I (In the formula, R represents H, an alkyl group containing 1 to 5 carbon atoms or an alkanoyl group containing 1 to 5 carbon atoms, and R ₁ is H or 1 to 5 carbon atoms. A compound represented by the formula II (Wherein R is as defined above) or an activated derivative thereof can be prepared according to the formula III: (Wherein R is as defined above) or a activated derivative thereof. 3. Formula I (Wherein R represents a hydrogen atom and R ₁ represents H or an alkyl group containing 1 to 5 carbon atoms). (In the formula, R represents an alkyl group containing 1 to 5 carbon atoms.) A method comprising enzymatically hydrolyzing a compound represented by the formula: