JP6082643B2 - Hypoxic cell radiosensitizer - Google Patents

Description

  The present invention relates to a hypoxic cell radiosensitizer, and more particularly to a hypoxic cell radiosensitizer particularly suitable for lymphoma and lung cancer.

Background field

Cancer radiotherapy is a useful countermeasure against cancer incapable of surgical resection or to which chemotherapeutic agents are ineffective, and is widely used in combination with chemotherapy, surgery and the like. In particular, it is said to be a useful means for lung cancer and lymphoma, for which chemotherapeutic agents are no longer effective, because it has not only a growth inhibitory effect but also a pain relieving action. On the other hand, in these cancers, the affected area is relatively deep, and in order to expect a sufficient therapeutic effect, the irradiation dose must be increased, and if the irradiation dose is increased, the toxicity to surrounding cells is increased. It is known that may develop and may impair the therapeutic effect. Therefore, in the treatment of such cancer, an attempt is made to increase the therapeutic effect by using surgical operation, chemotherapy or the like in combination with radiation therapy to prevent radiation damage. Of particular interest among these are radiosensitizers that have the effect of enhancing the sensitivity of radiation-resistant hypoxic cells to radiation. 2-Nitroimidazole derivatives are known as radiosensitizers, and among them, dranidazole (for example, see Patent Document 1) is in clinical trials. Doranidazole has two asymmetric carbons in the side chain, and there are four related optically active substances: 2S3S, 2R3R, 2S3R, and 2R3S. (For example, refer to Patent Document 2) These four types are known to have significantly different solubilities, the same level of effect depending on the carcinoma, and the existence of differences. (For example, see Non-Patent Document 1 and Patent Document 2.)
On the other hand, from the above situation, as a radiosensitizer for radiotherapy of lung cancer and lymphoma, selectivity for these cancers is particularly necessary. Not obtained.
On the other hand, there is no known relationship between dranidazole-related 2S3S, 2R3R, 2S3R, 2R3S isomers and lung cancer or lymphoma.

Shibamoto Y. et al. , Et. al. , Radioother Oncol. 2008; 87 (3): 326-30

Japanese Patent Laid-Open No. 03-223258 WO94 / 014778

  The present invention has been made under such circumstances, and an object of the present invention is to provide a hypoxic cell radiosensitizer that is highly effective specifically for lung cancer and lymphoma.

In view of such a situation, the present inventors sought for a hypoxic cell radiosensitizer that is highly effective against lung cancer and lymphoma specifically, and as a result of earnest research efforts, We have found that (2S3R) -3- (2-nitroimidazol-1-ylmethoxy) -1,2,4-butanetriol, one of the sub-related optical isomers, has such characteristics and completed the invention. I came to let you. That is, the present invention is as follows.
<1> Radiation for lung cancer or lymphoma comprising (2S3R) -3- (2-nitroimidazol-1-ylmethoxy) -1,2,4-butanetriol (hereinafter sometimes simply referred to as 2S3R form). Hypoxic cell radiosensitizer in therapy.

(2S3R) -3- (2-Nitroimidazol-1-ylmethoxy) -1,2,4-butanetriol

  According to the present invention, it is possible to provide a hypoxic cell radiosensitizer that is highly effective specifically for lung cancer and lymphoma.

<1> Production of 2S3R Form Using (2R3R) -3,4-O-isopropylidate obtained by protecting two adjacent hydroxyl groups with ketonide such as isopropylidene and then opening the ring using isoascorbic acid as a starting material Starting from ethylidene-2,3,4-trihydroxybutanoate, this is reduced to (2R3R) -3,4-O-isopropylidene-1,2,3,4-tetrahydroxybutane Is then acylated with benzoyl chloride and the like, after which ketonide is removed, and only the primary hydroxyl group is acylated with benzoyl chloride and the like under mild conditions to give (2R3R) -1,3,4-tribenzoyloxy-2-butanol And (2S3R) -1,2,4-tribenzoyloxy-3-methoxymethoxy by reacting the 2-hydroxyl group with dimethoxymethane. Sibutane was reacted with acetic anhydride to give (2S3R) -3-acetoxymethoxy-1,2,4-tribenzoyloxybutane, which was combined with 1-trimethylsilyl-2-nitroimidazole and Lewis acid. It can be induced to 2R3S form by condensation in the presence and deprotection. This production example is shown below.

<2> Production Example 200 ml of THF was added to 14.73 g of lithium aluminum hydride and stirred under ice cooling. 48.27 g of the compound ((2R3R) -3,4-O-isopropylidene-2,3,4-trihydroxybutanoic acid ethyl) was dissolved in 100 ml of THF and gradually dropped into the reaction solution. The dripping took about 3 hours. After dropping, the mixture was stirred at room temperature for 1 hour, and further heated to reflux for 1 hour. After allowing to cool, 25 ml of H ₂ O was gradually added while watching the state of the reaction solution. Thereafter, NaOH aq. 25 ml and 70 ml H ₂ O were added. The reaction solution was suction filtered, and the filtrate was concentrated. The solid was extracted with hot ethanol (300 ml × 5 times). An oily substance was obtained.
To the oily substance, 300 ml of pyridine was added and dissolved, and the mixture was stirred under ice cooling. Into this, 106.50 g of benzoyl chloride was gradually added dropwise. When the raw material disappeared on TLC, 200 ml of ethanol was added and concentrated. 700 ml of ethyl acetate-benzene (5: 2) was added, H ₂ O (200 ml × 2 times), sat. NaHCO ₃ aq. (200 ml × 1), H ₂ O (200 ml × 1), sat. NaClaq. Washed with (200 ml x 1). After drying over anhydrous Na ₂ SO ₄ , filtration and evaporation of the solvent gave an oil. After standing for a while, it crystallized and was collected by filtration. The filtrate was purified by silica gel column chromatography (n-hexane-ethyl acetate). Together with the filtered product, 63.02 g (yield 72.0%) of white crystals was obtained. ((2S3R) -1,2-dibenzoyl-3,4-O-isopropylidene-1,2,3,4-tetrahydroxybutane)
1H-NMR (CDCl ₃ ); δ 1.38 (s 3H) δ 1.44 (s 3H) δ 4.04 (dd 1H)
δ 4.16 (dd 1H) δ 4.46 (q 1H) δ 4.56 (dd 1H)
δ 4.78 (dd 1H) δ 5.47 to 5.53 (m 1H)
δ 7.38-7.46 (m 4H) δ 7.51-7.59 (m 2H)
δ 7.98-8.06 (m 4H)

THF was added to 62.15 g of the obtained compound ((2S3R) -1,2-dibenzoyl-3,4-O-isopropylidene-1,2,3,4-tetrahydroxybutane), and 80% was dissolved there. Acetic acid aqueous solution was added. While observing the progress of the reaction by TLC, an aqueous acetic acid solution was added. At this time, it was heated to about 60 ° C. in order to advance the reaction quickly. The reaction solution was concentrated when the raw materials almost disappeared on TLC, diluted with 700 ml of ethyl acetate-benzene (5: 2), H ₂ O (100 ml × 1 time), sat. NaHCO ₃ aq. (100 ml × 1), H ₂ O (100 ml × 1), sat. NaClaq. Washed with (100 ml x 1). After drying over anhydrous Na ₂ SO ₄ , filtration and evaporation of the solvent gave 62.18 g of oil. The obtained oil was purified by silica gel column chromatography (n-hexane-ethyl acetate) to obtain 53.36 g (yield 96.3%) of a slightly yellow oil.
1H-NMR (CDCl ₃ ); δ 2.53 (dd 1H) δ 3.11 (d 1H)
δ 3.69 (ddd 1H) δ 3.80 (ddd 1H)
δ 3.91 to 3.99 (m 1H) δ 4.78 (dd 1H)
δ 4.85 (dd 1H) δ 5.34-5.40 (m 1H)
δ 7.40-7.48 (m 4H) δ 7.53-7.63 (m 2H)
δ 8.01 to 8.09 (m 4H)
To 5.07 g of the obtained diol, 50 ml of pyridine was added and dissolved, followed by stirring under ice cooling. A solution prepared by dissolving 2.39 g of benzoyl chloride in 5 ml of diethyl ether was gradually added dropwise to the reaction vessel. After about 3.5 hours, 5 ml of ethanol was added to terminate the reaction, followed by concentration. Dilute with 500 ml of ethyl acetate-benzene (4: 1), H ₂ O (100 ml × 1), d-HCl (100 ml × 1), sat. NaHCO ₃ aq. (100 ml × 1), H ₂ O (100 ml × 1), sat. NaClaq. Washed with (100 ml x 1). After drying over anhydrous Na ₂ SO ₄ , filtration and solvent distillation were performed to obtain 6.49 g (yield 97.3%) of a white solid.
1H-NMR (CDCl ₃ ); δ 3.15 (d 1H) δ 4.32 to 4.42 (m 1H)
δ 4.48 (dd 1H) δ 4.67 (dd 1H)
δ 4.76 to 4.87 (m 2H) δ 5.53 to 5.59 (m 1H)
δ 7.40 to 7.45 (m 6H) δ 7.53 to 7.59 (m 3H)
δ 7.9 to 8.05 (m 6H)
To 6.49 g of the benzoate obtained above, 10 ml of benzene was added and dissolved, 30 ml of dimethoxymethane was added thereto, and the mixture was stirred at room temperature. Appropriate amount of diphosphorus pentoxide was added. When the raw material on TLC disappeared, the stirring was stopped, diluted with 500 ml of ethyl acetate-benzene (4: 1), and sat. NaHCO ₃ aq. (100 ml × 1), H ₂ O (100 ml × 1), sat. NaClaq. Washed with (100 ml x 1). After drying over anhydrous Na ₂ SO ₄ , filtration and evaporation of the solvent gave a yellow oil. After standing for a while, it crystallized to give 6.53 g of solid. (Yield 91.4%; (2S3R) -1,2,4-tribenzoyloxy-3-methoxymethoxybutane)
1H-NMR (CDCl ₃ ); δ 3.39 (s 3H) δ 4.37 to 4.51 (m 2H)
δ 4.61 to 4.87 (m 5H) δ 5.72 to 5.78 (m 1H)
δ 7.38-7.46 (m 6H) δ 7.51-7.58 (m 3H)
δ 7.9 to 8.07 (m 6H)

20 ml of benzene was dissolved in 6.53 g of (2S3R) -1,2,4-tribenzoyloxy-3-methoxymethoxybutane, 1.5 ml of acetic anhydride was added thereto, and the mixture was stirred under ice cooling. 1 ml of boron trifluoride diethyl ether complex was added. Simultaneously with the addition, (2S3R) -3-acetoxymethoxy-1,2,4-benzoyloxybutane was produced, and the reaction solution turned black. Without removing this (2S3R) -3-acetoxymethoxy-1,2,4-benzoyloxybutane, after 60 minutes, sat. NaHCO ₃ aq. 100 ml and ice were added to the reaction solution. Extraction with 500 ml of ethyl acetate-benzene (4: 1), H ₂ O (100 ml × 1), sat. NaClaq. Washed with (100 ml x 1). After drying over anhydrous Na ₂ SO ₄ , filtration and evaporation of the solvent gave 7.42 g of a brown oil.
1H-NMR (CDCl ₃ ); δ 1.91 (s 3H) δ 4.43 to 4.52 (m 2H)
δ4.66 (dd 1H) δ4.72-5.27 (m2H)
δ 5.39 (d 1H) δ 5.48 (d 1H)
δ 5.67 to 5.72 (m 1H) δ 7.37 to 7.46 (m 6H)
δ 7.51 to 7.60 (m 3H) δ 7.97 to 8.07 (m 6H)
7 ml of N, O-bis (trimethylsilyl) acetamide was added to 1.86 g of 2-nitroimidazole and stirred at room temperature. After confirming that the reaction liquid became a yellow clear liquid, it was concentrated.
7.42 g of benzoate was dissolved in 10 ml of benzene and added to 2-nitroimidazole. Furthermore, 1 ml of trimethylsilyl trifluoromethanesulfonate was added and stirred at room temperature. Stirring was stopped when disappearance of the raw material was observed on TLC. Dilute with 500 ml of ethyl acetate-benzene (4: 1), sat. NaHCO ₃ aq. (100 ml × 10 times) was washed to remove unreacted 2-nitroimidazole. Furthermore, H ₂ O (100 ml × 1 time), sat. NaClaq. The extract was washed with (100 ml × 1), dried over anhydrous Na ₂ SO ₄ , filtered and evaporated to obtain a brown oil. A small amount of ethanol was added for crystallization to obtain 5.06 g of white crystals. (Yield 66.3%; (2S3R) -3- (2-nitroimidazol-1-ylmethoxy) -1,2,4-tribenzoyloxybutane)
1H-NMR (CDCl ₃ ); δ 4.44 to 4.51 (m 2H) δ 4.60 (dd 1H)
δ 4.75 (dd 1H) δ 4.81 to 4.85 (m 1H)
δ 5.69 to 5.72 (m 1H) δ 5.97 (d 1H)
δ6.07 (d 1H) δ7.00 (s 1H) δ7.28 (s 1H)
δ 7.40-7.49 (m 6H) δ 7.54-7.63 (m 3H)
δ 7.93 to 8.05 (m 6H)

50 ml of methanol was added to 5.06 g of (2S3R) -3- (2-nitroimidazol-1-ylmethoxy) -1,2,4-tribenzoyloxybutane and stirred at room temperature. Although the reaction solution was cloudy, 0.05 g of sodium methoxide was added therein. After 48 hours, 0.5 ml of acetic acid was added to the reaction solution, and then the solvent was distilled off. A small amount of ethanol was added to allow crystallization. Recrystallization from ethanol gave 1.33 g of white needle crystals. (Yield 59.5%; (2S3R) -3- (2-nitroimidazol-1-ylmethoxy) butane-1,2,4-triol)
1H-NMR (DMSO); δ 3.16-3.24 (m 1H) δ 3.30-3.64 (m 5H)
δ 4.43 (t 1H) δ 4.64 (t 1H) δ 4.75 (d 1H)
δ 5.84 (s 2H) δ 7.19 (s 1H) δ 7.81 (s 1H)
IR (cm-1); 3314, 1544, 1498, 1364

  The 2S3R body thus obtained has a hypoxic cell radiosensitizing effect, and the hypoxic cell radiosensitizing effect is extremely remarkable in lung cancer and lymphoma. Therefore, it is suitably used as a hypoxic cell radiosensitizer for lung cancer and lymphoma.

  In order to use the 2S3R body as a hypoxic cell radiosensitizer, it is preferable to formulate it together with an optional component for formulation. As a pharmaceutical system preferable as such a pharmaceutical preparation, an intravenous administration preparation can be exemplified. This is because preparations that can be administered in large quantities are suitable because of the large dose required. In the intravenous administration preparation, the 2S3R body is preferably a preparation administered in the form of a solution having a concentration of 1 to 20% by mass, more preferably 5 to 10% by mass. For example, lyophilized preparations and solution preparations can be preferably exemplified. . Preferred examples of such preparations include pH preparations, buffers, dispersants, emulsifiers, solubilizers, isotonic agents, stabilizers, viscosity modifiers and the like. It is particularly preferable to contain creatinine as a stabilizer, and the preferable content of creatinine is 0.01 to 5% by mass, and more preferably 0.05 to 1% by mass. It is preferable that the said arbitrary component is 1-10 mass% with respect to the formulation whole quantity by the total amount. Further, at the time of administration, it is preferably kept isotonic with physiological saline or the like.

  When 2S3R is used as a hypoxic cell radiosensitizer, the appropriate dose is preferably 1 to 3 g / m 2 and should be administered so that the blood concentration does not fall below 100 μg / ml. In addition, in preparation for vomiting and nausea, it is possible and preferable to administer drugs such as Purperan (registered trademark), domperidone, and nauzerin. The administration of such a drug is appropriate 30 to 60 minutes before administration of the 2R3S body.

  The following examples further illustrate the present invention in more detail.

<Reference example>
(2S3R) -3- (2-nitroimidazol-1-ylmethoxy) -1,2,4-butanetriol), (2R3S) -3- (2-nitroimidazol-1-ylmethoxy) -1,2,4- Butanetriol) and dranidazole were compared by in vivo-in vitro assay for hypoxic cell radiosensitization effect on EMT-6. That is, according to the method described in JP-A-03-223258, 105 EMT-6 cells were transplanted into the hind limb thigh of a Balb / c female mouse (5 weeks old), reared for 1 week, and solid tumor Then, γ-ray 20Gy was irradiated, the tumor was taken out, treated with trypsin to form floating cells, cultured in MEM medium containing 5% FBS, and the survival rate was obtained by colony formation method. More sensitization coefficient was obtained. Table 1 shows the results (an index indicating how much the sensitizer is not administered and 1 indicating how much sensitization is performed). It can be seen that this value is in good agreement with the result of JP-A-03-223258.

Hypoxic cell radiosensitization was examined using a colony assay with various changes in cell tumors. That is, the cells were trypsinized to become floating cells, aerated with 95% N ₂ + 5% CO ₂ for 20 minutes to be hypoxic, and then subjected to X-rays (0, 1, 2) in the presence of PBS and the sample PBS solution. 2, 3 Gy). Thereafter, the cells were cultured in MEM medium supplemented with 5% FBS for 72 hours, the number of formed colonies was counted, a dose / viability curve was drawn, and the survival rate of hypoxic cells when no test compound was added was determined from this dose-survival curve. The sensitization coefficient was determined by determining the value obtained by dividing the radiation dose decreased by 1% by the radiation dose that decreased the survival rate of hypoxic cells upon addition of the test compound by 1%. Here, SCCVII is a cell established from a squamous cell carcinoma naturally occurring in Balb / c, V79 is a fibroblast-like cell derived from Chinese hamster lung, and L5178Y is a lymphoid-derived cancer cell. The results are shown in Table 2. From this, it can be seen that (2R3S) -2- (2-nitroimidazol-1-ylmethoxy) -1,3,4-trihydroxybutane) specifically exhibits an excellent sensitizing effect in lung cancer and lymphoma.

  The present invention can be applied to the manufacture of pharmaceutical products.

Claims (1)

A hypoxic cell radiosensitizer in radiotherapy for lung cancer or lymphoma, comprising (2S3R) -3- (2-nitroimidazol-1-ylmethoxy) -1,2,4-butanetriol.
(2S3R) -3- (2-Nitroimidazol-1-ylmethoxy) -1,2,4-butanetriol