JPH0449524B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing novel antitumor compounds. Many useful antitumor agents have been developed today. For example, daunomycin is a potent antitumor compound and can be an effective agent for killing neoplastic cells. However, its use is limited due to its toxicity to normal tissues. The selectivity of anti-tumor compounds towards tumor cells is enhanced by strategies that specifically concentrate the drug at the tumor site. One method for this purpose is to use various carriers for drugs, and in addition to antitumor antibodies, lectins, liposomes, and the like are used as carriers. The present inventors have repeatedly conducted various studies from the viewpoint of technological diversification in order to achieve the same objective as above, and found that an anti-tumor compound was chemically modified with arachidonic acid and docosahexaenoic acid. The present invention was completed based on the discovery that the toxicity of tumorous compounds to normal cells can be reduced, and at the same time, the targeting effect of the compounds on tumor sites can be improved. The present invention consists of a method for producing an antitumor complex, characterized by reacting an antitumor compound with arachidonic acid, docosahexaenoic acid, or a reactive derivative thereof. The antitumor compound used in the present invention has an antitumor activity and a group reactive with arachidonic acid, docosahexaenoic acid, or a reactive derivative thereof (hereinafter referred to as
Any group may be used as long as it has a reactive group (referred to as A) (for example, an amino group, a hydroxyl group, etc.). Such compounds include anthracycline antitumor compounds (eg, daunorubicin, doxorubicin, adriamycin, etc.). The reactive derivatives of arachidonic acid and docosahexaenoic acid used in the present invention are reactive derivatives in the carboxyl group and may be those commonly used in acylation reactions, such as acid halides (acid chlorides). , acid bromide, etc.), acid anhydrides, mixed acid anhydrides, etc. This reaction is usually carried out in the presence of a condensing agent (eg, water-soluble carbodiimide, etc.). The reaction between an antitumor compound and arachidonic acid or docosahexaenoic acid is usually carried out in a solvent that does not inhibit the reaction. As the solvent, for example, organic solvents such as dimethylformamide, water, and mixed solvents thereof are used. The pH is preferably 4 to 5, and the reaction temperature is preferably 10 to 30°C, particularly room temperature. Moreover, the reaction time is usually 2 to 8 hours. The binding ratio between the antitumor compound and the fatty acid in the complex thus obtained is determined by the number of reactive groups A in the antitumor compound; for example, daunorubicin, doxorubicin, and adriamycin have one amino group; Antitumor compound 1
One mole of the fatty acid will be amide bonded per mole. The complex can be isolated and purified, for example, by making the reaction solution alkaline and extracting it with a solvent (e.g., chloroform), or by eluating the extract with column chromatography (e.g., applying it to a silica gel column and chloroform:acetone=7). :3, the complex elutes first). The complexes of the present invention are all new compounds, and are useful as more effective antitumor agents because their toxicity is significantly reduced and the targeting effect on tumor cells is increased compared to the raw antitumor compounds. It is. When used as such a medicine, it can be administered orally or parenterally in the same dosage form as the raw antitumor compound. Further, the dose of the complex may be smaller than the dose of the raw antitumor compound. Hereinafter, the present invention will be specifically explained with reference to Examples and Experimental Examples. Example 1 Water-soluble carbodiimide in 10.3 mg of arachidonic acid
Add 24.1mg of dimethyl formamide and 3
Add ml and dissolve. Daunorubicin under stirring 10.0
2 ml of an aqueous solution containing mg was added dropwise. After about 6 hours of reaction, 4N sodium hydroxide was added to make the aqueous solution alkaline, and the reaction solution was mixed with chloroform (40ml x 3).
Extracted twice. Finally, it was washed with water, dehydrated with Na ₂ SO ₄ and dried. This was dissolved in a solution of chloroform:acetone=7:3 and developed on a silica gel column equilibrated with the same solution (the developing solution was also the same chloroform/acetone solution as above). Free daunorubicin is adsorbed and the complex is eluted. The properties of the composite thus obtained are as follows. The ultraviolet absorption spectrum is shown in FIG. The amount of daunorubicin in the complex is 14 μM. Figure 2 shows the ultraviolet absorption spectra of control groups, i.e. daunorubicin alone (20 μM), a mixture of daunorubicin and fatty acids (20 μM each), and fatty acids alone (20 μM) in methanol solutions. is increased. Number of moles of arachidonic acid bound: Number of moles of daunorubicin bound = 1:1 Soluble in ethanol, methanol and ether, insoluble in water. Example 2 A complex was synthesized in the same manner as in Example 1 using docosahexanoitsucic acid instead of arachidonic acid. Example 3 A complex was synthesized in the same manner as in Example 1 using doxorubicin instead of daunorubicin. Experimental Example 1 After intraperitoneal administration of 1×10 ⁴ rat ascites liver cancer AH66 cells to male rats (body weight 150 g ± 10; 6 animals per group), various complexes and control substances were administered on days 3, 5, and 7. were dissolved in normal rat serum, and an amount equivalent to 200 μg of each was administered intraperitoneally to examine the extension of survival days in rats. The results are shown in Table 1 below.

[Table] Experimental Example 2 After intraperitoneal administration of 1×10 ⁴ rat ascites liver cancer AH66 cells to male rats (weighing approximately 150 g), 3.
On days 5 and 7, various complexes and controls were dissolved in normal rat serum and 200 μl of daunorubicin was added.
The prolongation of the survival period of rats was investigated by intravenously administering an amount equivalent to 100 g. The results were as shown in Table 2.

【table】 [Brief explanation of the drawing]

Figure 1 shows the ultraviolet absorption spectrum of daunorubicin-arachidonic acid complex (daunorubicin amount 14 μM), and Figure 2 shows daunorubicin alone (20 μM), daunorubicin and fatty acid mixture (each
20 μM) and fatty acid alone (20 μM) in methanol.

Claims (1)

[Scope of Claims] 1. An anthracycline antitumor compound is reacted with arachidonic acid, docosahexaenoic acid, or a reactive derivative thereof, and the amino group of the anthracycline antitumor compound is reacted with arachidonic acid, docosahexaenoic acid, or its reactive derivative. A method for producing an antitumor complex, which comprises forming an amide bond with a carboxyl group of a derivative. 2. The method for producing an antitumor complex according to claim 1, wherein the anthracycline antitumor compound is daunorubicin or doxorubicin. 3. The method for producing an antitumor complex according to claim 1, which comprises reacting 1 mole of an anthracycline antitumor compound with 1 mole of arachidonic acid, docosahexaenoic acid, or a reactive derivative thereof.