Novel compound and antitumor agent containing the same

Abstract

summary The present invention discloses a novel compound that exhibits excellent antitumor effects, particularly excellent anticancer effects against solid cancers such as pancreatic cancer, and an antitumor agent containing the compound as an active ingredient. The compound of the present invention is represented by the following general formula [I]: [C1] JPEG0007766386000007.jpg40146 (in formula [I], X represents a halogen, and n represents an integer of 5 to 13) In formula [I], X is preferably iodine, and n is preferably 12. An antitumor agent contains this compound as an active ingredient. The tumor is preferably a solid cancer, and particularly preferably pancreatic cancer.

Description

[Technical Field]

[0001] The present invention relates to a novel compound and an antitumor agent containing the same. [Background technology]

[0002] The present applicant previously discovered that an analogue of a component purified from rice bran is effective as an antitumor agent, and obtained a patent for this discovery (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5364532 Summary of the Invention [Problem to be solved by the invention]

[0004] The compound described in Patent Document 1 is useful as an antitumor agent, but it goes without saying that it would be even more desirable if a compound with even stronger antitumor effect could be provided.

[0005] An object of the present invention is to provide a novel compound that exhibits excellent antitumor effects, particularly excellent anticancer effects against solid cancers such as pancreatic cancer, and an antitumor agent containing the compound as an active ingredient. [Means for solving the problem]

[0006] As a result of extensive research, the present inventors synthesized a novel compound having a specific structure containing three phenyl groups and a polyethylene glycol moiety, and discovered that this novel compound exhibits excellent antitumor effects, thereby completing the present invention.

[0007] That is, the present invention provides the following. (1) The following general formula [I]

[0008] [ka]

[0009] (In formula [I], X represents a halogen, and n represents an integer of 5 to 13.) A compound represented by the formula: (2) The compound according to (1), wherein X in the formula [I] is I. (3) The compound according to (2), wherein n is 12 in the formula [I]. (4) An antitumor agent containing the compound according to any one of (1) to (3) as an active ingredient. (5) The antitumor agent according to (4), which is a therapeutic agent for treating solid cancer. (6) The antitumor agent according to (5), wherein the solid cancer therapeutic agent is a pancreatic cancer therapeutic agent. [Effects of the Invention]

[0010] The compound of the present invention exhibits excellent antitumor effects, particularly excellent antitumor effects against solid cancers such as pancreatic cancer. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows the results of HPLC-NMR of the compounds of the present invention synthesized in the following Examples. [Figure 2] FIG. 1 shows the anticancer effects of the compounds of the present invention, comparative compounds, and controls against pancreatic cancer, obtained in the following Examples. [Figure 3] FIG. 1 shows the killing activity of the compounds of the present invention against pancreatic cancer cells and normal cells, obtained in the following Examples. [Figure 4] This is a scanning electron microscope image of Aspergillus fumigatus, which is approximately 1 μm in size. [Figure 5] This is a transmission electron microscope photograph showing Aspergillus fumigatus spores entering HeLa cells. [Figure 6]This is a transmission electron micrograph showing Aspergillus fumigatus spores attached to the surface of normal cells. [Figure 7] This is a transmission electron microscope image showing Aspergillus fumigatus spores entering HeLa cells. [Figure 8] This is a transmission electron microscope photograph showing the germination of Aspergillus fumigatus. DETAILED DESCRIPTION OF THE INVENTION

[0012] As described above, the compound of the present invention has a structure represented by formula [I]. In formula [I], X is a halogen (I, Br, Cl, or F), preferably iodine. Also, in formula [I], n is an integer of 13 or less, preferably an integer of 8 to 13, and more preferably 12.

[0013] The compounds of the present invention can be synthesized by conventional organic chemical synthesis methods using benzene derivatives and polyethylene glycol as starting materials. An example of the synthesis method is described in detail in the Examples below.

[0014] The compound of the present invention has an antitumor effect, particularly an effect for treating solid cancers, particularly pancreatic cancer. Therefore, an antitumor agent, particularly an agent for treating solid cancers, particularly pancreatic cancer, containing the compound of the present invention as an active ingredient is provided.

[0015] When the compound of the present invention is used as an antitumor agent, the route of administration is not particularly limited, and the compound can be administered orally or parenterally, such as intravenously, intramuscularly, subcutaneously, enterally, intraperitoneally, or locally to a tumor.

[0016] When the compound of the present invention is used as an antitumor agent, the dosage is determined appropriately depending on the condition and body weight of the patient, the route of administration, etc., but is usually about 0.01 μg to 10 mg, particularly about 0.1 μg to 1 mg, per kg of body weight per day.

[0017] When the compound of the present invention is used as an antitumor agent, it can be formulated into dosage forms such as injections, tablets, capsules, liquids, suppositories, etc., together with commonly used excipients such as physiological saline and starch, by conventional methods.

[0018] The present invention will be specifically described below based on examples, although the present invention is not limited to the following examples. [Example]

[0019] Example 1 Synthesis of Compounds Compounds of the above formula [I] in which X is I and n is 9 or 12 were synthesized by the following method.

[0020] (1) Synthesis of intermediate A

[0021] [ka]

[0022] Under a nitrogen stream, dodecaethylene glycol (D2901, 71.17 g, 130.0 mmol), toluene (740 mL), benzyltriethylammonium chloride (B0444, 3.08 g, 13.5 mmol), 25% aqueous sodium hydroxide solution (47.7 g, 297.8 mmol), and sodium chloride (5.5 g, 94.8 mmol) were sequentially added to a reaction vessel. p-Toluene-2-yl chloride (T0272, 28.4 g, 148.9 mmol) was dissolved in 284 mL of toluene and added dropwise over 4 hours at room temperature. The mixture was then aged overnight. Completion of the reaction was confirmed by TLC, and tap water and ethyl acetate were added for separation. The aqueous layer was extracted with dichloromethane and then combined with the previously extracted organic layer and washed with saturated brine. The organic layer was dried over anhydrous magnesium sulfate, suction filtered, and the filtrate was concentrated to yield 89.3 g of crude product. This crude product was purified by silica gel column chromatography (ethyl acetate:methanol=100:0→10:1) to obtain 50.8 g of intermediate A (yield: 55.6%).

[0023] (2) Synthesis of Intermediate 1

[0024] [ka]

[0025] Under a nitrogen stream, 4'-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)biphenyl-4-ol (T3031, 35 g, 118.2 mmol), 1-bromo-4-(trimethylsilyl)benzene (B3357, 54.17 g, 236.4 mmol), and K2CO3 (49 g, 354.5 mmol) were sequentially added to a reaction vessel, followed by degassing and adding 700 mL of a 4:4 mixture of THF and ion-exchanged water. Tetrakis(triphenylphosphine)palladium(0) (T1350, 6.83 g, 5.9 mmol) was added, and the mixture was heated to reflux. After 48 h, the reaction was confirmed to be complete and cooled to room temperature. 10% aqueous ammonium chloride solution was added, and the organic layer was extracted with ethyl acetate. The organic layer was washed with saturated saline, dried over anhydrous magnesium sulfate, and suction filtered to concentrate the filtrate, yielding 77.8 g of crude product. This crude product was purified by silica gel column chromatography (hexane:ethyl acetate=4:1), and the resulting solid was suspended and washed in hexane to yield 33.8 g of intermediate 1 (yield: 89.6%).

[0026] (3) Synthesis of intermediate 2

[0027] [ka]

[0028] Under a nitrogen stream, intermediate 1 (33 g, 103.6 mmol) and dichloromethane (1650 mL) were added to a reaction vessel and stirred at room temperature for 1 hour to dissolve intermediate 1. Iodine monochloride (approximately 1.0 M dichloromethane solution, 114 mL, 114 mmol) was added dropwise to the reaction vessel at room temperature over 30 minutes. After the addition was complete, the mixture was aged overnight at room temperature. The reaction solution was suction filtered, and the resulting solid was washed with dichloromethane and dried in vacuo at 50°C to obtain 32.7 g of intermediate 2 (yield: 84.6%).

[0029] (4) Synthesis of I-8TPP (in formula [I], X is I and n is 12)

[0030] [ka]

[0031] Under a nitrogen stream, intermediate 2 (31.9 g, 85.6 mmol), potassium iodide (P1721, 1.18 g, 7.13 mmol), a DMF solution of intermediate A (50 g, 354.5 mmol), potassium carbonate (14.8 g, 107.0 mmol), and DMF (550 mL) were sequentially added and stirred at 80°C for 22 hours. After confirming the completion of the reaction and cooling to near room temperature, the target product was extracted into the organic layer with dichloromethane and tap water. The aqueous layer was further extracted with dichloromethane, and the combined organic layer was washed with saturated brine. The organic layer was dried over anhydrous magnesium sulfate, and the filtrate obtained through suction filtration was concentrated and dried to obtain 90.8 g of crude product. Dichloromethane (1000 mL) was added to this crude product and stirred. Insoluble matter was removed by suction filtration. The resulting filtrate was concentrated to dryness, yielding 77.5 g of crude product (2). This crude product (2) was purified by column chromatography (dichloromethane:THF = 5:1 → 2:1 → 1:1) to yield 46.7 g of column-purified product (1). This column-purified product (1) was further purified twice by silica gel column chromatography (dichloromethane:methanol = 50:1 → 20:1 → 10:1) to yield 37.0 g of column-purified product (2) (LC purity: 96.7%). This column-purified product (2) was further purified using a medium-pressure preparative purification system (ODS column, acetonitrile:ion-exchanged water = 50:50 → 100:0) to yield 34.6 g of I-8TPP (yield: 53.8%, LC purity: 99.1%).

[0032] The molecular weight of the obtained compound I-8TPP was 900.84. The results of HPLC-NMR are shown in Figure 1. HPLC conditions: Column: Mightysil RP-18 GP (product name) ODS column (4.6 mm x 250 mm (5 μm)) Temperature: 40℃ Mobile phase: acetonitrile / water = 70 / 30 Flow rate: 1.4ml / min UV wavelength: 254nm, injection amount 3.0μl Injection volume: 3.0μL

[0033] A polymer having 9 polymerization numbers of ethylene glycol units (n=9) was also synthesized by the same method as above.

[0034] Example 2 Anticancer activity against pancreatic cancer Materials and Methods mouse 1) Thirty 4-week-old male nude mice (BLAB / c SLc nu / nu Japan SLC Co., Ltd.) were purchased and quarantined for one week. After a week of environmental acclimation, frozen and thawed tumor cells were transplanted subcutaneously into the right outer thigh of the nude mice. Two to three weeks passed before the administration of the test substance.

[0035] 2) Tumor cell transplantation Cryopreserved human pancreatic cancer cells (MIAPACA-2 / / ATCC) were subcultured and injected subcutaneously into the right outer thigh of nude mice at 5x10 cells per mouse. 6 Tumor cells were transplanted at 1000 cells / animal. Tumors developed in 19 out of 30 mice, or approximately 60% of the 30 mice. The number of mice administered in the experiment was 12 (average of 4 mice / cage) x 3 cages.

[0036] 3) Administered medication Compound I-8TPP prepared in the above example was administered to the mice. Gemzar Injection 200 mg (hereinafter referred to as "GEM"), a commercially available antimetabolite anticancer drug used in the treatment of pancreatic cancer, and gemcitabine hydrochloride for injection (Eli Lilly Japan, Kobe, Hyogo Prefecture) were used as reference drugs (pancreatic cancer comparison drugs) for the antitumor effect against MIAPACA-2 cell tumors. Compound I-8TPP was administered to mice at a dose of 40 mg / kg / 0.2 mL / mouse in sterile PBS(-). GEM was administered at a dose of 20 mg / kg / 0.2 mL / mouse in sterile saline (Japanese Pharmacopoeia, physiological saline, Otsuka Pharmaceutical Co., Ltd.).

[0037] 4) Administration method The animals were given intraperitoneal injections every other day. The injections were continued until death. For at least the first month (a total of 15 injections), all 12 animals in the three groups were in good health, and no deaths occurred.

[0038] 5) Measurement of tumor volume and body weight Tumor volume was measured using a digital caliper, and the volume was calculated using the following formula. Tumor volume = {major axis x minor axis of transplanted tumor volume} 2 / 2}

[0039] 6) Grouping The grouping was summarized as follows: i) Control group (4 mice, saline, 0.2 mL / mouse), tumor volume: 124 mm 3 (Weight: 20.3g) ii) Tumor-bearing control group (4 mice, GEM, 20 mg / kg / 0.2 mL / mouse), tumor volume: 157 mm 3 (Weight: 21.2g) iii) Administration group (4 animals, I-8TPP, 40 mg / kg / 0.2 mL / animal), tumor volume: 143 mm 3 (Weight: 21.1g)

[0040] The relationship between the number of days from the start of administration and the tumor volume is shown in FIG.

[0041] As shown in Figure 2, the anticancer effect of the compound of the present invention against pancreatic cancer (MIAPACA-2 derived tumor cell line) was clearly observed when compared with the control (sterile saline), and was also higher than that of Gemzar, a known anticancer drug. Furthermore, all animals in the control group died within 70 days after the start of administration, and all animals in the GEM-administered group died within 120 days after the start of administration. In contrast, all animals in the group administered Compound I-8TPP, a compound of the present invention, survived until 649 days after the start of administration (the day of autopsy for preparing pathological specimens). Therefore, the long-term life-prolonging effect of the compound of the present invention was also demonstrated.

[0042] Example 3 Toxicity The cytotoxicity of I-8TPP was investigated in vitro using the WST method. The cells used were pancreatic cancer cells, Mia PaCa-2, and normal fibroblast cells. The results are shown in Figure 3.

[0043] As shown in Figure 3, the cell viability of Mia PaCa-2 was almost 0% at an effective concentration of 0.2 μM, whereas the viability of fibroblasts was approximately 80% at the same concentration, demonstrating that I-8TPP specifically kills cancer cells.

[0044] Reference example As described above, the compound of the present invention is an analog of a component purified from rice bran, and this component has been found to be contained in Aspergillus fumigatus spores. A scanning electron microscope photograph of the spores is shown in Figure 4. It has been found that Aspergillus fumigatus spores enter and kill cancer cells but do not enter normal cells. A transmission electron microscope photograph showing Aspergillus fumigatus spores entering HeLa cells is shown in Figure 5. In contrast, Aspergillus fumigatus spores cannot enter normal cells, remaining on the cell surface and eventually detaching. A transmission electron microscope photograph of Aspergillus fumigatus spores touching (but unable to enter) the surface of normal cells (fibroblasts) is shown in Figure 6. Furthermore, a transmission electron microscope photograph of Aspergillus fumigatus spores entering HeLa cells is shown in Figure 7. Furthermore, it was found that when Aspergillus fumigatus spores were subjected to freezing and thawing, they were able to break through their hard shell and germinate. Figure 8 shows a transmission electron microscope photograph of Aspergillus fumigatus germination. As shown in Figure 8, germination after freezing and thawing caused the protrusions on the surface to disappear, making it possible to extract the contents of the cell. [Industrial Applicability]

[0045] The present invention provides novel compounds useful as anticancer agents for cancers such as pancreatic cancer.

Claims

1. The following general formula [I] 【Chemistry 1】 (In formula [I], X represents a halogen, and n represents an integer of 5 to 13.) A compound represented by the formula:

2. The compound according to claim 1, wherein X is I in the formula [I].

3. The compound according to claim 2, wherein n is 12 in the formula [I].

4. An antitumor agent comprising the compound according to any one of claims 1 to 3 as an active ingredient.

5. The antitumor agent according to claim 4, which is a therapeutic agent for treating solid cancer.

6. The antitumor agent according to claim 5 , wherein the solid cancer therapeutic agent is a pancreatic cancer therapeutic agent.

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