KR900006232B1 - Process for preparing elliplicine glycosides - Google Patents

Abstract

Ellipticine glycosides of formula (I) are prepd. by treating ellipticine cpd. of formula (II) with arabinose deriv. of formula (III) in the presence of trialkylamine as acid catcher in an organic solvent. R1 is H, OH, C1-3 alkyloxy or C2-8 acyloxy; R2 is H or C1-6 alkyl; R3 is acyl; X is Cl or Br. (I) have strong antimalignant tumor activity and useful as carcinostatics.

Description

[Name of invention]

Method for preparing ellipsine glycosides

Detailed description of the invention

The present invention relates to a method for producing an ellipsine glycoside having the following general formula (I).

Wherein R ¹ represents a hydrogen atom, a hydroxyl group, an alkyloxy group having 1 to 3 carbon atoms or an acyloxy group having 2 to 8 carbon atoms, and R ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms R ³ represents an acyl group and X represents a chlorine or bromine atom.

The novel ellipsine derivative having the following general formula (II), which is easily derived from the ellipsin glycoside represented by the general formula (I), can be used as an antitumor agent since it has strong anticancer or antitumor activity.

Wherein R ² and X are as defined above and R ⁴ represents a hydrogen atom or a hydroxyl group.

Ellipsin, i.e., 5,11-diethyl-6H-pyrido- [4,3-b] -carbazole (ie, R = H in the following formula (A)) and 9-methoxyellipticin (ie Pyridocarbazoles such as R = OCH ₃ in the following formula (A) and 9-hydroxyellipticin (ie R = OH in the following formula (A)) are apidospermina and oak. It is known as alkaloids contained in the leaves of cyan.

, 437-441(1981)]은 다음의 일반식(B)를 갖는 2-N-메틸-9-히드록시엘립티시늄 초산염(셀립튬)이 유방암에 대해 효과적이라고 보고하였다.Recently, J. Rouess et al. Collaborators [Cancer Bulletin (Paris),

, 437-441 (1981), reported that 2-N-methyl-9-hydroxyelliptinium acetate (celiptium) having the following general formula (B) is effective against breast cancer.

Also R.W. Co-researcher of Guthrine [J. Drug Chemistry, 18 (7), 755-760) (1975), found that ellipsine and 9-methoxyl for tumors of animals used in experiments, lymphoid leukemia L-1210 in rats, and sarcoma 180 (solid). Lipids reported to be effective, and Japanese Patent Publication Nos. 58-35196 and British Patent No. 1436080, which were examined, reported that the activity of 9-hydroxyellipsine against lymphatic leukemia L-12l0 in rats was 9-methoxy It was reported to be 100-1000 times higher than activity.

As described above, compounds having a pyridocarbazole skeleton are useful compounds because they have anticancer or antitumor activity. Many studies on the synthesis of these compounds are described, for example, in L.K Dalton et al. J. Chem, 20, 2715-2727 (1967)], A H. Jackson et al. Chem. Soc. Perkin I, 1698-1704 (1977), J.Y Rellerman-Deu et al. (Tetrahedron Letters, 15, 1261-1264 (1978)) and European Patent Specification No. 9445. Moreover, US Pat. No. 4434290 describes compounds in which certain substituents have been introduced into the pyridocarbazole skeleton have activity against murine lymphoid leukemia L-1210.

However, ellipsine, 9-methoxy ellipsine, and 9-hydroxy ellipsine have not been used clinically as antitumor agents. This is because of other reasons, that is, the water solubility of these compounds is poor. Although unexamined Japanese Patent Publication No. 58-222087 does not oxidize the 2-alkyl-9-hydroxy elliptinium salt to introduce amino acids, oligopeptides, nucleotides, or nucleosides into the 10-position of this backbone. Nevertheless, these compounds nevertheless do not provide the desired life-extension effect against lymphatic leukemia L-1210 in rats.

In order to solve the above-mentioned problems, the inventors have found that the nitrogen at the 2-position of the ellipsin derivative having the general formula (II) as shown in Unexamined Japanese Patent Publication No. 61-37799 or EP-A-0173462 Compounds with various sugars bound through glycoside binding were synthesized.

Accordingly, it is an object of the present invention to provide a method for preparing a novel ellipsine glycoside by improving the prior art. Other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, an ellipsine compound having the following general formula (III) is reacted with an arabinose derivative having the following general formula (IV) in the presence of trialkylamine in an organic solvent as an acid trapping agent. A method for producing an ellipsine glycoside having the following general formula (I) is provided.

Wherein R ¹ represents a hydrogen atom, a hydroxyl group, an alkyloxy group having 1 to 3 carbon atoms, or an acyloxy group having 2 to 8 carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ³ represents an acyl group and X represents a chlorine or bromine atom.

The present inventors have focused on the antitumor or antitumor activity of ellipsin to develop various useful derivatives with pharmacological activity derived from naturally occurring skeletons in the course of the study. I tried to get it.

The inventors have already found that the above-mentioned problems can be solved by introducing a sugar into the nitrogen at the 2-position of the ellipsine derivative as shown in Unexamined Japanese Patent Publication No. 61-37799 (or EP-A-0173462). Found. In this method, however, weakly basic metal compounds are used as acid trapping agents. Of these metal compounds, cadmium carbonate is most suitable. However, after the reaction has ended, these inorganics must be removed from the product, for example by column chromatography. Furthermore, metal cadmium forms complex salt compounds with ellipsine derivatives, thus preventing the separation of ellipsine. Therefore, careful care is required in separation. These problems can be solved by using an acid trapping agent that can be dissolved in an organic solvent instead of a weakly basic metal compound, but it is required to find a reagent that can further increase yield and stereospecific selectivity.

Several proposals have been made to quaternize nitrogen atoms in pyridone skeletons, for example, by J. Chem. Soc. 3727-3732 (1957). However, even if these preparation methods are studied in more detail, optically active nigotinamide nucleotides cannot be prepared. Thus, studies on the preparation of optically active compounds effectively have shown that addition of a weakly basic metal compound such as cadmium carbonate, calcium carbonate, or copper carbonate to the reaction system can successfully produce the desired compound. .

However, this method requires the addition of the weakly basic metal compound to the reaction system, and therefore requires additional steps to efficiently separate and purify the desired compound formed during the reaction. Therefore, the present inventors have continued to find an acid trapping agent which can achieve the above-mentioned object without requiring a separation and purification process, and it is found that the use of a trialkylamine compound is most suitable for achieving this purpose. I found out the fact.

That is, according to the present invention, it is preferable to react 1.5 to 2.5 equivalents of the arabinose derivative having the general formula (IV) and 1 equivalent of the trialkylamine with the ellipsin compound having the general formula (IV). This reaction can be easily carried out by heating in an organic solvent.

Suitable trialkyl amines that can be used as acid trapping agents in the present invention include, for example, triethylamine, diisopropylethylamine, dipropylethylamine, tripropylamine, triisopropyl amine and tributylamine.

Organic solvents that can be used in the present invention include, for example, nitromethane, acetonitrile, propionitrile, benzene, toluene, xylene, dimethylformromamide, dimethyl sulfoxide and aniline. Although there is no limitation on the reaction temperature and the reaction time, the reaction is preferably performed for 4 to 10 minutes under reflux temperature.

By carrying out the reaction as described above, the desired ellipsine glycoside having the general formula (I) can be obtained. After the reaction is completed, the reaction compound is cooled to form a precipitate, and the resulting precipitate is separated by conventional means (eg, filtration, centrifugation). In this way, the desired ellipsine glycoside having the general formula (I) can be obtained in high yield.

Although arabino pyranosyl halides in the process for preparing ellipsine glycosides according to the present invention are turned into typical halogenated sugars, erythrose, threose, ribose, xylose, lyxose, glucose, mannose, allose, altrose Other sugars such as glucose, idose, galactose, taloose, rhamnose and fucose can also be used as the halogenated sugar. When arabinopyranosyl halides are used, the desired compounds can be obtained quantitatively in practice by using triethylamine. However, when such other sugars are used, the stereospecific selectivity of the product compound is reduced.

Examples of the present invention are as follows. However, the present embodiments are not intended to limit the present invention.

Example 1

Preparation of 2- (2,3,4-tri-O-acetyl-α'-L-arabinopyranosyl) -9-methoxyellipthysinium bromide.

8.28 g (0,03 mol) of 9-methoxy ellipsine, 20.34 g (0.06 mol) of 2,3,4-tri-O-acetyl-β-L-arabinofyranosyl bromide and 4.2 ml of triethylamine 0.03 mole) was suspended in 300 ml of acetonitrile and the resulting mixture was heated at reflux for 5 minutes.

The reaction mixture thus obtained was rapidly cooled in watertight and the precipitate thus formed was collected on the clade. The precipitate was washed three times with a mixture of chloroform and ether (14) and then the precipitate (α: β = 100: 1.1) was recrystallized in 880 ml of acetonitrile. Thus, 7.56 g (yield 41%) of the desired compound was obtained. The mother liquor of the recrystallization was concentrated and recrystallized again to obtain 3.53 g (yield 19%) of the desired compound. The physical properties of the compound thus obtained are as follows.

The proportions of α- and β-products were determined based on the area ratio of HPLC measured under the following conditions.

Column: Nova-pack C-18, 15 cm x 3 9 mm

Mobile phase: 0.1 M ammonium acetate. Acetic acid buffer solution (pH3): Methanol = 2: 1

Flow rate: 1.5m1 / min

Search: 318nm (ultraviolet detector)

The physical properties of the compound thus obtained are as follows.

Properties: Amorphous Crystal

Infrared Spectrum (KBr, cm ^-1 ): 1750, 1640, 1590, 1480, 1420, 1370, 1300, 1240, 1220, 1120, 1090, 1060, 1030, 960, 930, 810

: ,228(ε15000) 249(ε24000) 256(ε24000) 268(ε24000) 282(ε21000) 325 (ε 52000)Ultraviolet spectrum

: 228 (ε15000) 249 (ε24000) 256 (ε24000) 268 (ε24000) 282 (ε21000) 325 (ε 52000)

Mass spectrum (SIMS, m / z): 535 [C ₂₉ H ₃₁ N ₂ O ₈ ] +

¹ HNMR spectrum (CDCl ₃ , δppm, internal reference = TMS) 1.68 (3Hs), 1.98 (3H, s), 2.03 (3H, s), 2.32 (3H, s), 2.46 (3H, s), 3.94 (3H , s), 4.41 (1H.dd, J = 13 Hz, 1.8 Hz), 4.65 (1H, d, J = 13 Hz), 5,50 (2H, m), 5.61 (1H, brs), 7.06 (1H) , brs), 7.20 (1H, d, J = 9 Hz, 1-H) 7.32 (1H, dd, J = 2 Hz, 7 Hz) 7.61 (1H, d, J = 7 Hz) 8.12 (1H, d, J = 9 Hz) 8.17 (1H, d, J = 9 Hz) 10.18 (1H, s) 11.94 (1H, brs)

Reference Example 1

Preparation of 2-α-L-arabinofyranosyl-9-hydroxyellipthynium bromide.

40 g (0.065 mol) of 2- (2,3,4-tri-O-acetyl-α-L-arabinopyranosyl) -9-methoxyelliptinium was dissolved in 650 ml of an aqueous 47% bromic acid solution. The resulting solution was heated at reflux for 30 minutes.

The reaction mixture thus obtained was cooled with ice, 650 ml of water was added and then cooled with ice for 3 hours. The precipitate formed by this method was separated by centrifugation at 4000 rpm for 10 minutes and then washed with a small amount of cold water. The precipitate thus obtained was dissolved in 500 ml of warm water and recrystallized by adding 1000 ml of ethyl alcohol. After recrystallization, the precipitated crystals were collected, washed three times with ethyl alcohol and dried to give 26.54 g (86% yield) of the desired compound. In addition, the mother liquor of the recrystallization was concentrated and cooled to further obtain the desired compound 1.239 (yield 4%). The physical properties of the compound thus obtained are as follows.

The optical purity of this compound was determined using HPLC under the following conditions.

Column: Shim-Pack CLC-ODS 15cm × 6mm

Mobile phase: Acetonitrile: 0.02 M NaH ₂ PO ₄ . H ₃ PO ₄ buffer = 1: 5

Flow rate: 1.0m1 / min or

Mobile phase: Acetonitrile: 0.02 M NaH ₂ PO ₄ . H ₃ PO ₄ buffer = 1: 4

Flow rate: 1.5m1 / min

The physical and chemical properties of the resulting compound are as follows.

Melting Point> 250 ° C (Decomposition)

Infrared spectrum (KBr, cm ^-1 ): 3250, 1640, 1600, 1400, 1420, 1220, 1200, 1150, 1090, 1060, 810

: 227(ε14000) 249(ε23000) 267(ε25000) 282(ε22000) 324(ε52000)Ultraviolet spectrum

: 227 (ε14000) 249 (ε23000) 267 (ε25000) 282 (ε22000) 324 (ε52000)

Mass spectrum (SIMS, m / z): 395 [C ₂₂ H ₂₃ N ₂ O '' ⁺

¹ HNMR Spectrum ^* (DMSO-d6, δ ppm, 2.85 (3H, s), 3.65 (1H, m), 3.90 (3H, m) 4.08 (1H, d), 5.12 (1H, d), 5.24 (1H, d ), 5.61 (1H, d), 5.74 (1H, d, J = 8.5 Hz, 1-H), 7.18 (1H, dd, J = 2.9 Hz) 7.55 (1H, d, J = 9 Hz) 7.86 (1H, d, J = 2Hz) 8.51 (2H, ABq) 9.45 (1H, brs) 10.03 (1H, s) 12.08 (1H, brs)

* Quantum chemical shift (δ2.50) of CD ₂ HSOCD3 was used as internal standard

Elemental analysis: C ₂₂ H ₂₃ N ₂ O ₅ Br 2H ₂ O

Calculated Value: C; 51.67, H; 5.32, N; 5.48

Found: C; 51.57, H; 5 31, N; 5.40

Reference Example 2

Preparation of 2,3,4-tri-O-acetyl-β-L-arabinopyranosyl bromide.

50 g (0.33 mol) of L-arabinose were suspended in 250 ml of pyridine, 200 ml (217 g, 2.13 mol) of acetic anhydride were added, and the mixture was left to stir overnight at room temperature. 50 ml of methyl alcohol was added to the reaction mixture under ice cooling, and the solvent was distilled off in vacuo. Excess solvent and reagent excess were removed by azeotropic distillation with ethyl alcohol and water.

The residue obtained above was dissolved in 100 ml of acetic acid under ice cooling, and 100 ml of a 30% hydrobromic acid solution in acetic acid was added and stirred for 3 hours. The reaction mixture thus obtained was suspended with 800 ml of methylene chloride and washed with water. The liquid layer was reextracted with 200 ml of methylene chloride. The mixed organic layer was washed in this order using cold water, saturated aqueous sodium bicarbonate solution and cold water, and dried over magnesium sulfate. After concentration, the residue was recrystallized from ether and washed with cold ether. This gave 59.6 g (yield = 53%) of the desired compound.

Evaluation Example

The anticancer or antitumor activity of the ellipsine derivative was measured using experimental tumor L-1210 in mice as follows.

(1) Animals used: BDF ₁ female, 6 weeks old. 6 animals per group of average weight 17-18g

(2) Type of tumor used: L 1210 (lymphocytic leukemia cells of mice) was intraperitoneally injected (ip) at 10 ⁵ cells / mouse.

(3) Sample administration method

L 1210 was injected intraperitoneally into rats, and samples were administered once daily for 5 days from 24 hours after L 1210 cells were injected.

(4) Evaluation method: The activity of the sample was determined by the increased lifetime (ILS%) of the average number of days of survival of the group to which the sample was administered compared to the control.

This result is shown in Table 1. The results shown in Table 1 make it clear that the ellipsine derivatives of the present invention have good or significant anticancer or antitumor efficacy against rat lymphoid leukemia L 1210. 80-day viable count means the number of live mice for 80 days after rat lymphocytic leukemia L 1210 was administered to the rat.

Thus, it is believed that the ellipsine derivatives of the present invention are effective as antitumor agents.

TABLE 1

Claims (4)

An ellipsine compound having the following general formula (III) is reacted with an arabinose derivative having the following general formula (IV) in the presence of a trialkyl amine in an organic solvent as an acid trapping agent. A method for producing an ellipsine glycoside having (I).

Wherein R ¹ represents a hydrogen atom, a hydroxyl group, an alkyloxy group having 1-3 carbon atoms, or an acyloxy group having 2-8 carbon atoms, and R ² represents a hydrogen atom or an alkyl group having 1-6 carbon atoms R ³ represents an acyl group and X represents a chlorine or bromine atom. The method of claim 1 wherein the trialkyl amine is triethylamine, tripropylamine, triisopropylamine, diisopropylethylamine, or tributylamine. The method of claim 1, wherein the organic solvent is acetonitrile, nitromethane, or propionitrile. 2. The method of claim 1, wherein said ellipsine glycoside having formula (I) is an optically active compound.