JPS6136492B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides novel antitumor agents, namely, formulas [], (However, in the formula, R ₁ and R ₂ are C ₁ to _{C 4} lower alkyl groups, acyl groups, carboxyl groups, alkoxycarbonyl groups, and the carbonyl group moiety is semicarbazone, thiosemicarbazone, aminodinohydrazone, oxime, oxime acetate. A saturated 5-acyl group formed by ring closure of the acyl group and R ₁ and R ₂ together.
The present invention relates to an antitumor agent containing a nitrofuryl vinyl compound (hereinafter abbreviated as the compound of the present invention) represented by the following (hereinafter abbreviated as the compound of the present invention) as an active ingredient. Today, many efforts are being made to develop better antitumor drugs, but one of the important pharmacological properties that antitumor drugs should have is selective toxicity, that is, to the host's normal cells. In terms of improving the pharmacological activity of selectively destroying tumor cells without causing damage, no drug has yet been provided that is fully satisfactory. As a result of intensive research into antitumor agents with better selective toxicity, the present inventors discovered remarkable selective antitumor effects of each compound represented by the above formula [], and arrived at the present invention. . The above-mentioned compound used in the present invention and its manufacturing method itself are disclosed in Japanese Patent Publications No. 46-35057, No. 46-35058, No. 47
-10873, 47-10874, 46-17790, 48-
As disclosed in patent publications such as 25189 and 46-35065, these compounds are usually 5-
It is produced by dehydrating and condensing nitrofurfural and a compound having an active methyl group in acetic anhydride, and the physical properties of its main compounds are shown in Table 1 below.

【table】

[Table] Next, the unique pharmacological effects of the compounds of the present invention are summarized. (1) When N-methyl-N'-nitro-N-nitrosoguanidine (abbreviated as MNNG) is orally administered to rats every day, gastric cancer occurs at a high rate after 30 weeks. By doing so, the occurrence of gastric cancer is significantly suppressed. That is, male Wistar rats (6 weeks old) were divided into MNNG administration group, MNNG + compound of the present invention administration group, and MNNG + 5-fluorouracil administration group, and after being kept for 30 weeks, the presence or absence of tumors was observed. The results shown in Table 2 were obtained. In the same table, tumor development was observed at a high rate of 66.7% in the rats that were orally administered water containing 50 ppm of MNNG for 30 weeks, whereas in the group administered with the compound of the present invention, 1.5 mg/Kg/day was administered. The tumor incidence was extremely low at 0-20%, and a remarkable tumor suppressing effect was observed. As a comparative example, 5-fluorouracil was 1.5
When administered mg/Kg/day, tumor incidence was 35.3%
The effect was not as good as that of the compound of the present invention.
Although it was impossible to administer 5-fluorouracil at 7.5 mg/Kg/day due to its high toxicity, in the case of the compound of the present invention, even when administered at 7.5 mg/Kg/day,
Similar to the 1.5mg/Kg/day administration case, there were no side effects and the tumor incidence was low. (2) The compound of the present invention exhibits a remarkable suppressive effect on human cancer (melanoma). That is, a melanoma Seki strain was planted in a medium, the compound of the present invention was added to the medium at a concentration of 1 ppm, and after culturing in a carbon dioxide incubator for 5 to 6 days, the number of cells was counted and shown in Table 3 below. The results shown are obtained. As is clear from these results, all of the compounds of the present invention exhibit a remarkable inhibitory effect on melanoma at a concentration of 1 ppm. It is truly surprising that a substance with low toxicity such as the compound of the present invention destroys melanoma cells at a concentration as low as 1 ppm, and this fact indicates that the compound of the present invention is a substance with excellent selective toxicity. It can be said that this clearly proves that. Incidentally, the most widely used screening system currently incorporates leukemia-type animal cancers that proliferate rapidly, such as L-1210 and P-388, and the substances selected by this system are currently not available in Japan. It is well known that sufficient treatment effects have not been achieved for gastric cancer and lung cancer, which are the most frequently affected cancers in humans. Furthermore, the screening method of the present invention belongs to the latter method, and it allows the degree of selective toxicity of antitumor drugs to be determined extremely accurately. Detected. (3) As shown in Example 3 below, the compound of the present invention has a high life-prolonging effect even in mouse animal experiments on Sarcomer 180, which is a typical screening. As shown in Examples 4 and 5 below, the compounds of the present invention have extremely low toxicity (LD ₅₀ >20g/
kg), it can be said to be safe. Next, the present invention will be explained in detail with reference to examples. Example 1 Stomach cancer suppressive effect of the compound of the present invention 120 male Wistar rats, 6 weeks old and weighing 200 to 230 g, were divided into the following groups and an experiment was conducted. Group 1: 20 rats were given free access to drinking water containing 50 ppm of MNNG,
CE-2) and reared for 30 weeks. Groups 2 to 11: Rats were divided into groups of 20 rats each and each group was given free access to drinking water containing 50 ppm of MNNG, and fed with solid feed (manufactured by Claire) containing 10 ppm of the compound of the present invention, and reared for 30 weeks. did. Group 12: 20 rats were given free access to drinking water containing 50 ppm of MNNG, and
They were fed solid feed mixed with 10 ppm and reared for 30 weeks. Group 13: 20 rats fed basal diet (Claire solid feed)
CE-2) for 30 weeks. Rats were divided into five rats in wire mesh cages at room temperature 22°C.
The animals were raised in a breeding room at ~24°C and humidity of 60-70%, and feed intake was measured every other day, and body weight was measured once a week. After rearing, the surviving rats were sacrificed, their stomachs were removed and observed, and then fixed in 10% formalin.
Tissue sections were prepared by embedding in paraffin, stained with hematoxylin and eosin, and then examined under a microscope. The results are shown in Table 2.

【table】

[Table] As is clear from Table 2, the group to which water containing 50 ppm of MNNG was orally administered for 30 weeks had a high tumor incidence rate of 66.7%. However, the tumor incidence in the group administered with the compound of the present invention at 1.5 mg/Kg/day was 0 to 15%, which was higher than that of Comparative Example 5.
- The tumor incidence rate is lower than that of fluorouracil (35.3%), which is superior. Example 2 Effect of the compound of the present invention on melanoma Calf serum-3.5 containing 2 ml of RPMI1640 (1:9)
2 × 10 ⁴ human melanoma cells (Seki strain) were transferred to a cmφ plastic jar and incubated at 37°C in the presence of saturated water vapor and carbon dioxide gas-containing air (5% carbon dioxide gas).
After culturing for 24 to 26 hours, the compound of the present invention dissolved in DMSO or ethanol is added to the medium at a concentration of 1 ppm, and culturing is continued under the above conditions for an additional 5 days. After culturing, floating cells and cells attached to the bottom of the shear dish are removed by treatment with 0.25% trypsin, and the total cell number is calculated. A group containing no drug was used as a control example, and a group containing 5-fluorouracil (1 ppm) was used as a comparative example. The results are shown in Table 3.

【table】

[Table] As is clear from the results, the compound of the present invention suppresses the proliferation of melanoma cells at a concentration as low as 1 ppm, and has a higher proliferation inhibition rate than the comparative example 5-fluorouracil. Example 3 Sarcoma-180, a compound of the present invention
Effect on Sarcomer-180 1×10 ⁶ intraperitoneally in a group of 20 ICR mice (weight 20-24 g, 5 weeks old)
After 24 hours of transplantation, a suspension of the test compound in physiological saline was intraperitoneally administered once a day, and the survival effect was observed. Mitomycin C, a commercially available anticancer drug, was used as a comparative drug. The life extension effect was expressed as the day when half of the test animals died (half death date).

【table】

[Table] Example 4 Acute toxicity test ICR mice (female weighing 20 to 24 g) were placed in a group of 8 mice in a transparent polycage, and the compound of the present invention was administered.
After pulverizing to 0.5 to 3μ, a 5% starch solution containing 20% of Twin-80 (manufactured by Kishida Chemical Co., Ltd.) was prepared, and the solution was forcibly administered orally once using a metal probe. After one week, the mortality rate was calculated using the Litchfield-Wilcoxon equation.
_LD50 values were calculated. The results are shown in Table 5. Acute toxicity value of the substance of the present invention
The LD ₅₀ (PO) is 20 g/Kg or more, which is much higher than the LD ₅₀ value of the commercially available anti-tumor agent in the comparative example, and is extremely safe.

【table】

[Table] Example 5 Subacute toxicity test Subacute toxicity was determined by rat (Sprague Dowley female body weight)
Each group of 10 animals (110 to 115 g) was housed in wire mesh cages, and 0.2% of the compound of the present invention was added to the feed and given ad libitum. The control group was given ad libitum without any supplements. Feed intake was measured every other day, and body weight was measured once a week. Urinalysis was performed once a month for urine sugar, urine protein, pH, and occult blood. At the end of rearing, a blood test was performed, and the sacrificed animals were dissected to observe the presence or absence of abnormalities.The organs were fixed in formalin and embedded in paraffin to prepare tissue sections, which were stained with hematoxylin and eosin and then examined under a microscope. No differences from the control group were observed in feed intake, weight gain, mortality rate, urine test, or blood test. Table 6 shows the pathological and autopsy results. Abnormal anatomical and histological findings throughout all organs;
No disability was detected.

【table】

[Table] Example 6 Formulation example Prescription example 1 Nitrofuryl vinylcyclohexenothiazole
200g Lactose 790g Sucrose fatty acid ester 10g The mixture of the above composition is thoroughly mixed using a pulverizer to prepare a powder for oral administration. Prescription example 2 Nitrofuryl vinylcyclohexenothiazole
200g Lactose 590g Starch 100g Sucrose fatty acid ester 10g Water (containing 1% CMC-Na) 100ml Make a mixture of the above composition using finely ground nitrofurylvinylcyclohexenothiazole, knead it, and then extrude it into granules using an excavator. . This is dried and screened with a sieve (No. 32 to No. 200) to prepare granules for oral administration. Prescription example 3 Nitrofuryl vinylcyclohexenothiazole
200g White petrolatum 790g Polyoxyethylene sorbitan ester 10g A mixture of the above composition is kneaded at 50 to 60°C to prepare an ointment for the skin. When the compound of the present invention is used orally as a therapeutic agent, it is thoroughly pulverized and mixed with substances commonly used as excipients such as starch and lactose, and if necessary, surfactants, dispersants, disintegrants, etc. It can be used as powder, granules, capsules, and tablets by adding auxiliary materials. The dosage of the compound of the present invention is 0.05 to 100 mg, preferably 0.1 to 20 mg per kg of human body weight per day.
Administration can be divided into 1 to 4 times a day. Also,
Dispersed or dissolved in liquids such as water, glycerin, alcohol, propylene glycol, diluents, or ointment bases such as fats, fatty oils, vaseline, lanolin, liquid paraffin, etc., and if necessary, auxiliary materials such as emulsifiers, dispersants, etc. can be added to make a formulation convenient for external skin application. Furthermore, appropriate auxiliary materials can be added to increase the solubility, tissue permeability, or safety and retention of the compounds of the present invention in the blood. In this example, the pharmaceutical formulation will be specifically shown.
None of these are intended to limit the scope of the present invention. The compounds of the present invention are useful as safe, long-term therapeutic agents for cancers of the digestive system, such as gastric cancer, esophageal cancer, and rectal cancer. Furthermore, the compounds of the present invention are useful in the treatment of melanoma, and when used in combination with radiation therapy or surgery to eradicate melanoma cells,
It is expected that its usefulness will be further demonstrated.

Claims (1)

[Claims] 1 Formula [] (However, in the formula, R ₁ and R ₂ are C ₁ to _{C 4} lower alkyl groups, acyl groups, carboxyl groups, alkoxycarbonyl groups, and carbonyl groups, and are semicarbazone, thiosemicarbazone, aminodinohydrazone, oxime, and oxime acetate. acyl group, or
An antitumor agent containing a nitrofuryl vinyl compound as an active ingredient, in which R ₁ and R ₂ represent a saturated 5- to 6-membered ring formed by ring closure, and X represents an oxygen or sulfur atom. 2 In formula [], R ₁ = R ₂ = -CH ₃ , X=O
The antitumor agent according to claim 1. 3 In formula [], R ₁ = R ₂ = -CH ₃ , X = S
The antitumor agent according to claim 1. 4 In formula [], R ₁ =-CH ₃ , R ₂ =-
The antitumor agent according to claim 1, wherein COCH ₃ , X=S. 5 In formula [], R ₁ =-CH ₃ ,
The antitumor agent according to claim 1, wherein [Formula] X=S. 6 In formula [], R ₁ =-CH ₃ ,
The antitumor agent according to claim 1, wherein [Formula] X=S. 7 In formula [], R ₁ =-CH ₃ ,
The antitumor agent according to claim 1, wherein [Formula] X=S. 8 In formula [], R ₁ =-CH ₃ ,
The antitumor agent according to claim 1, wherein [Formula] X=S and HA=acid. 9 In formula [], R ₁ =-CH ₃ , R ₂ =-
The antitumor agent according to claim 1, wherein COOC ₂ H ₅ , X=S. 10. The antitumor agent according to claim 1, wherein in formula [], R ₁ and R ₂ are both ring-closed to form a cyclohexene ring, and X=O. 11. The antitumor agent according to claim 1, wherein in formula [], R ₁ and R ₂ are both ring-closed to form a cyclohexene ring, and X=S. 12. The antitumor agent according to claim 1, which is used for cancer of the digestive system. 13. The antitumor agent according to claim 1, wherein the cancer of the digestive system is gastric cancer, esophageal cancer, or rectal cancer. 14. The antitumor agent according to claim 1, which is used for melanoma. 15. The antitumor agent according to claim 1, which is in an oral administration form. 16. The antitumor agent according to claim 15, wherein the oral administration form is a powder, granule, tablet, or capsule. 17. The antitumor agent according to claim 1, which is in the form of an ointment.