JPH08269062A - Pyripyropene derivative - Google Patents

Abstract

(57) [Summary] [Purpose] To enhance the activity of pyripyropene to inhibit acylcoenzyme A cholesterol acyltransferase. [Structure] A compound represented by the following formula: [Wherein R ₁ is O together with OH, an acyl group or R ₁ ′, R ₁ ′ is H, or together with R ₁ is O, R ₂ is H (in this case, between the 5th and 13th positions: Double bond), OH, or R ₂ '
Together with O, R ₂ 'represents H or R ₂ together with O, or a bond at the 5-position, and Ac represents an acetyl group].

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to pyripyropene derivatives.

[0002]

2. Description of the Related Art Conventionally, some drugs for treating hyperlipidemia are known. As a therapeutic drug for hyperlipidemia,
(1) Cholesterol biosynthesis inhibition, (2) Cholesterol absorption inhibition, (3) Cholesterol catabolism promotion,
(4) A drug having an action of suppressing the synthesis of lipoprotein is known.

[0003]

In recent years, with the improvement of eating habits, symptoms caused by cholesterol accumulation such as hyperlipidemia and arteriosclerosis in adults have been regarded as a modern disease. Hyperlipidemia is known as one of the factors that promote the progression of arteriosclerosis, and can reduce ischemic heart disease by lowering blood cholesterol. Further, it is desired to develop a more effective and safe therapeutic drug for hyperlipidemia, particularly hypercholesterolemia, such that the incidence of myocardial infarction increases with hyperlipidemia.

Cholesterol becomes cholesterol ester by acyl group transfer from acyl coenzyme A,
It is accumulated intracellularly and in blood lipoproteins. The enzyme that catalyzes this acyl group transfer reaction is acyl coenzyme A cholesterol acyl transferase, which is deeply involved in the absorption of cholesterol from the intestinal tract and the formation of foam cells in the coronary arteries. Therefore, a substance that inhibits acylcoenzyme A cholesterol acyltransferase is presumed to be effective for such diseases. Under such circumstances, it is useful for treating adult diseases such as hyperlipidemia and arteriosclerosis based on it, to provide a substance having an acylcoenzyme A cholesterol acyltransferase inhibitory activity.

[0005]

As a result of continuing research on metabolites produced by microorganisms, the present inventors have found that acylcoenzyme A cholesterol transferase in a culture of FO-1289 strain isolated from a new soil. It was found that a substance having inhibitory activity was produced. Then, an acylcoenzyme A cholesterol acyltransferase inhibitory active substance was separated from the culture and purified to obtain each substance having the physicochemical properties described below. Since these substances have not been known at all in the past, this substance was identified as pyripyropene (FO-1).
289 substance). (JP-A-6-184158
issue)

The present inventors have synthesized various derivatives of pyripyropene for the purpose of further increasing the acylcoenzyme A cholesterol acyltransferase inhibitory activity of pyripyropene (hereinafter referred to as ACAT inhibitory activity). The present invention has been completed based on such findings, and provides a pyripyropene derivative represented by the following formula.

[0007]

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The pyripyropene derivative of the present invention is a compound in which the hydroxyl groups at the 7-position and / or the 13-position are oxidized, as shown in the above formula. Pyripyropene A, which is a raw material for the pyripyropene derivative of the present invention, is disclosed in JP-A-6-1841.
Manufactured according to the method described in No. 58.

Oxidation of hydroxyl group It is carried out by an ordinary method using chromic acid or dimethyl sulfoxide. Oxidation using chromic acid (Jones oxidation): Solvent: 3M aqueous solution of chromic sulfuric acid Solvent: (hydrated) acetone Reaction temperature: room temperature (cooling or heating conditions are possible)

Oxidation using chromic acid (PDC oxidation): Reagent: Pyridinium dichromate Solvent: Dichloromethane Reaction temperature: Room temperature (cooling or heating conditions are possible)

Oxidation with dimethyl sulfoxide (Sw
ern oxidation): Reagent: Prepare dimethyl sulfoxide and oxalyl chloride at -40 ° C Solvent: Dimethylsulfoxide, dichloromethane, etc. Base: triethylamine Reaction temperature: Cooling (-20 ° C, 0 ° C, etc.), room temperature

Silver Carbonate Oxidation (Fetizon Oxidation): Reagent: Silver Carbonate (Fetizon Reagent) Solvent: Benzene Reaction Temperature: Heat Reflux The compound obtained as above is silica gel, OD.
The target compound can be obtained as a pure product by purification by column chromatography such as S.

The physicochemical properties and biological properties of the compounds obtained by the above methods are shown below. In addition,
Biological properties include the following in vitro
50% inhibition of rat-derived acylcoenzyme A cholesterol acyltransferase by the activity measurement method
The inhibition value (IC ₅₀ ) is shown.

In vitro activity assay method: Inhibition of rat-derived acylcoenzyme A cholesterol acyltransferase activity: The effect on acylcoenzyme A cholesterol acyltransferase activity is determined by the method of Kuda et al. (The Journal of Antibiotics, 45 Volume 1626
Page, 1992), using a crude enzyme prepared from rat liver microsome fraction, using 300 μM bovine serum albumin, 30 μM in 100 mM phosphate buffer (pH 7.4).
M [1- ¹⁴ C] oleoyl -CoA (0.02μC
i), 30 μM cholesterol (dissolved in 1/30 weight Triton WR-1339) was added to make a total volume of 200 μl, reacted at 37 ° C. for 30 minutes, and reacted with a chloroform: methanol (1: 2) mixed solution To stop.

Next, total lipids were analyzed by the method of Holsch et al. (Journal of Biological Chemistry, Vol. 22,
Page 497, 1957), and after extraction of each lipid with TLC (Kieselgel GF ₂₅₄ , petroleum ether: diethyl ether: acetic acid = 90: 10: 1 as a developing solvent), the radioactivity incorporated in the cholesterol ester fraction was separated. Was analyzed by RI scanner (manufactured by Ambis) to measure the activity of acylcoenzyme A cholesterol acyltransferase. The concentration at which this enzyme activity was inhibited by 50% was calculated.
The results are shown below.

[0016]

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Compound number R ₁ R ₁ ′ R ₂ R ₂ ′ ACAT inhibitory activity (IC ₅₀ , μM) PR-51 OH H ═O 18.5 PR-98 ═O OH H 7.0 PR-50 ═O = O> 190 PR-19 = O H - 69 PR-114 OCOCH 3 H = O 2.1

Next, the mass spectrometry data of the pyripyropene derivative of the present invention will be described below. Compound number Composition formula Molecular weight Measured value Theoretical value PR-51 C ₂₉ H ₃₃ O ₉ N ₁ 539.581 FAB (+) 540.2220 (M + 1) 540.2233 PR-98 C ₂₉ H ₃₃ O ₉ N ₁ 539.581 FAB (+) 540.2218 ( M + 1) 540.2234 PR-50 C ₂₉ H ₃₁ O ₉ N ₁ 537.565 FAB (+) 538.2075 (M + 1) 538.2077 PR-19 C ₂₉ H ₃₁ O ₈ N ₁ 521.566 FAB (+) 522.2119 (M + 1) 522.2128 PR-114 C ₃₁ H ₃₅ O ₁₀ N ₁ 581.618 FAB (+) 582.2350 (M + 1) 582.2339

Next, the nuclear magnetic resonance spectrum ( ¹ H-NMR) and mass spectrometry (M
S) is shown in Table 1.

[0020]

[Table 1]

[0021]

INDUSTRIAL APPLICABILITY As described above, since the pyripyropene derivative of the present invention exhibits a remarkable inhibitory activity on acylcoenzyme A cholesterol, it is useful for preventing and treating diseases caused by human cholesterol accumulation.

Next, the present invention will be specifically described with reference to Reference Examples and Examples, but it goes without saying that the present invention is not limited thereto. Reference Example 1 291 mg of pyripyropene A was added to 80% methanol aqueous solution 1
It was dissolved in 0 ml and 1,8-diazabicyclo [5,4,4]
[0] Undeca-7ene (75 μl) was added, the mixture was stirred at room temperature for 10 minutes, and 0.1 ml of acetic acid was added, and the solvent was distilled off to obtain a crude product. This was subjected to silica gel column chromatography (developing solvent: dichloromethane-methanol (50:
1-7: 1) mixed solvent) to obtain 140.6 mg of a colorless powder of the compound.

Example 1 Compounds PR-50, PR-51: To a solution of 20 μl of oxalyl chloride in 0.5 ml of dichloromethane was added a solution of 35 μl of dimethyl sulfoxide in 0.1 ml of dichloromethane at −40 ° C., and then obtained in Reference Example 1. Compound 12m
After adding 1.5 g of dichloromethane solution (1.5 ml) and stirring for 15 minutes, triethylamine (500 μl) was added, stirring for 10 minutes, washing with water, and drying with anhydrous sodium sulfate, the solvent was distilled off to obtain a crude product. Obtained. This was purified by preparative thin-layer silica gel column chromatography (developing solvent: dichloromethane-methanol (20: 1) mixed solvent) to obtain 8.7 mg of a colorless powder of the target compound PR-50.
(Yield 73%), and yellow powder of PR-51 to 1.3.
mg (yield 11%) was obtained.

Example 2 Compound PR-98: 10.8 mg of the compound obtained in Reference Example 1
Was dissolved in 0.4 ml of dichloromethane, 11.6 mg of pyridinium dichromate was added, the mixture was stirred at room temperature for 8 hours, and then the insoluble matter was filtered. The filtrate was washed successively with 1N-hydrochloric acid, 5% aqueous sodium hydrogen carbonate solution and water, dried over anhydrous sodium sulfate, and the solvent was distilled off to obtain a crude product. This was purified by silica gel column chromatography (developing solvent: chloroform: methanol (50: 1) mixed solvent) to obtain 1.8 mg of colorless powder of the target compound PR-98. (Yield 17%)

Example 3 Compound PR-19: 14 mg of the compound obtained in Reference Example 1 was dissolved in 0.2 ml of dimethyl sulfoxide, 0.2 ml of acetic anhydride was added, and the mixture was stirred, dichloromethane was added, and the mixture was washed with water. Then, it was dried over anhydrous sodium sulfate and the solvent was distilled off to obtain a crude product. This was purified by preparative thin-layer silica gel chromatography (developing solvent: dichloromethane: methanol (20: 1) mixed solvent) to give the target compound PR.
7.1 mg of -19 colorless powder was obtained. (53% yield)

Example 4 Compound PR-114: 95% of 64 mg of pyripyropene A
Dissolve in 42 ml of acetone aqueous solution and use Jones reagent (3
M chromic acid-sulfuric acid aqueous solution) (0.5 ml) and added at room temperature for 2
After stirring for an hour, 0.1 ml of isopropanol was added. The precipitate was filtered off, the acetone was distilled off from the filtrate, the mixture was extracted with ethyl acetate, washed with water and saturated saline, and dried over anhydrous sodium sulfate, and the solvent was distilled off to obtain a crude product.
This was purified using silica gel column chromatography (developing solvent: dichloromethane-methanol (50: 1) mixed solvent) to obtain 64 mg of the target compound PR-114 colorless powder. (100% yield)

Claims (2)

[Claims] 1. The following formula: [Wherein R ₁ is O together with OH, an acyl group or R ₁ ′, R ₁ ′ is H, or together with R ₁ is O, R ₂ is H (in this case, between the 5th and 13th positions: Double bond), OH, or R ₂ '
Together with O, R ₂ 'represents H or R ₂ together with O, or a bond at the 5-position, and Ac represents an acetyl group]. 2. The pyripyropene derivative according to claim ₁ , wherein the groups R ₁ , R ₁ ′, R ₂ and R ₂ ′ are compounds selected from the group consisting of compounds having a combination of substituents shown below. Compound No. _{R 1 R 1 'R 2 R} 2' PR-51 OH H = O PR-98 = O OH H PR-50 = O = O PR-19 = O H - PR-114 OCOCH 3 H = O