CN108929369B

CN108929369B - 3R-indolylmethyl-6R-acidic amino acid modified piperazine-2, 5-dione, and synthesis, activity and application thereof

Info

Publication number: CN108929369B
Application number: CN201710363811.1A
Authority: CN
Inventors: 赵明; 彭师奇; 王玉记; 吴建辉; 张筱宜; 丛林
Original assignee: Capital Medical University
Current assignee: Capital Medical University
Priority date: 2017-05-22
Filing date: 2017-05-22
Publication date: 2021-08-24
Anticipated expiration: 2037-05-22
Also published as: CN108929369A

Abstract

The invention discloses (3R,6R) -3- (AA-amino n-hexanoylamino n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (AA in the formula is L-Asp residue and L-Glu residue). Discloses a preparation method thereof, discloses the anti-tumor activity thereof and discloses the anti-tumor metastasis activity thereof, so that the invention discloses the application thereof in preparing anti-tumor drugs and anti-tumor metastasis drugs.

Description

3R-indolylmethyl-6R-acidic amino acid modified piperazine-2, 5-dione, and synthesis, activity and application thereof

Technical Field

The invention relates to (3R,6R) -3- (AA-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione. Relates to a preparation method thereof, the antitumor activity thereof and the antitumor metastasis activity thereof, so that the invention relates to the application thereof in preparing antitumor drugs and antitumor metastasis drugs. The invention belongs to the field of biological medicine.

Background

Tumors seriously threaten the health of human beings. In addition to the poor prognosis of patients with tumors by themselves, metastasis associated with tumors further worsens the prognosis of patients. For example, more than 90% of patients with tumors die from metastases. Because the existing antitumor drugs have no effect of resisting tumor metastasis, the clinical curative effect of tumor chemotherapy is not ideal. The invention relates to a medicament for resisting tumor metastasis, which is an urgent clinical need. The inventors have previously disclosed that diketopiperazines of the four S, S-, R, R-, R, S-and S, R-configurations inhibit migration and invasion of HCCLM3 (highly metastatic human liver cancer cells) at a concentration of 0.5. mu.M. Later, the inventors further disclosed that R, R-configured diketopiperazines inhibited tumor metastasis to the lung in C57BL/6 mice at a dose of 5. mu. mol/kg. However, the lowest effective dose is 5. mu. mol/kg. To reduce the minimum effective dose, the inventors have developed various modifications to the butylamino group of the diketopiperazine in the R, R-configuration. After 3 years of exploration, it was found that acylation of the butylamino group of diketopiperazine of R, R-configuration with aminocaproic acid acylated with acidic side chain amino acids (L-Asp and L-Glu) not only reduced the minimum effective dose against tumor metastasis to 0.5. mu. mol/kg, but also reduced the minimum effective dose against tumors to 0.5. mu. mol/kg. Because the toxic and side effects of the medicine can disappear along with the reduction of the dosage, the reduction of the effective dosage by 10 times shows that the structure modification has outstanding technical effect. Based on these findings, the inventors have proposed the present invention.

Disclosure of Invention

The first aspect of the present invention provides (3R,6R) -3- (AA-amino-n-hexanoylamino) -6- (indole-3-methyl) -piperazine-2, 5-dione of the formula (wherein AA is a L-Asp residue and a L-Glu residue).

The second aspect of the present invention provides a method for synthesizing (3R,6R) -3- (AA-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (wherein AA is L-Asp residue and L-Glu residue), which comprises:

(1) D-Boc-Lys (Cbz) and D-Trp-OBzl are condensed to obtain D-Boc-Lys (Cbz) -D-Trp-OBzl;

(2) removing Boc from D-Boc-Lys (Cbz) -D-Trp-OBzl in ethyl acetate solution of hydrogen chloride to obtain D-Lys (Cbz) -D-Trp-OBzl;

(3) cyclizing D-Lys (Cbz) -D-Trp-OBzl in saturated ethyl acetate containing 5% sodium bicarbonate water solution to obtain (3R,6R) -3- (benzyloxycarbonylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (1);

(4) the compound 1 is subjected to hydrogenolysis to remove benzyloxycarbonyl to obtain (3R,6R) -3- (amino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (2);

(5) condensing amino-n-hexanoic acid methyl ester with Boc-AA [ AA is L-Asp (OMe) residue and L-Glu (OMe) residue ] to obtain Boc-AA-amino-n-hexanoic acid methyl ester (3a, b) [ AA is L-Asp (OMe) residue and L-Glu (OMe) residue ];

(6) demethylating compound 3a, b to give Boc-AA (OMe) -aminohexanoic acid (4a, b) (AA is L-Asp residue and L-Glu residue);

(7) condensing the compound 2 and the compounds 4a and b to obtain (3R,6R) -3- (Boc-AA (OMe) -amino-n-hexanoylamino) -6- (indole-3-methyl) -piperazine-2, 5-diketone (5a and b) (AA is L-Asp residue and L-Glu residue);

(8) demethylating the compound 5a, b to give (3R,6R) -3- (Boc-AA-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (6a, b) (AA is L-Asp residue and L-Glu residue);

(9) and (3R,6R) -3- (AA-amino-n-hexanoylamino) -6- (indole-3-methyl) -piperazine-2, 5-dione (7a, b) (AA is an L-Asp residue and an L-Glu residue) is obtained by removing Boc from the compound 6a, b in an ethyl acetate solution of hydrogen chloride.

The third aspect of the present invention is to evaluate the anti-lung cancer metastasis activity of (3R,6R) -3- (AA-amino-n-hexanoylamino) -6- (indole-3-methyl) -piperazine-2, 5-dione (wherein AA is L-Asp residue and L-Glu residue) in C57BL/6 mice.

The fourth aspect of the present invention is to evaluate the use of (3R,6R) -3- (AA-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (wherein AA is L-Asp residue and L-Glu residue) for inhibiting tumor growth in S180 mice.

Drawings

FIG. 1 is a scheme for the synthesis of (3R,6R) -3- (AA-amino-n-hexanoylamino) -6- (indole-3-methyl) -piperazine-2, 5-dione (6a, b). AA in 3a and 4a is the residue L-Asp (OMe) and AA in 3b and 4b is the residue L-Glu (OMe); i) dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBt), N-methylmorpholine (NMM), Tetrahydrofuran (THF); ii) a solution of hydrogen chloride in ethyl acetate; iii) ethyl acetate, 5% sodium bicarbonate; iv) Dimethylformamide (DMF), Pd/C, H₂(ii) a v) Dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBt), N-methylmorpholine (NMM), N, N-Dimethylformamide (DMF); vi) methanol, NaOH (2M).

Detailed Description

To further illustrate the invention, a series of examples are given below. These examples are purely illustrative and are intended to be a detailed description of the invention only and should not be taken as limiting the invention.

EXAMPLE 1 preparation of D-Boc-Lys (Cbz) -D-Trp-OBzl

7.7g (20mmol) of D-Boc-Lys (Cbz) was suspended in 100mL of anhydrous Tetrahydrofuran (THF), and 2.7g (20mmol) of 1-hydroxybenzotriazole (HOBt) and 5.0g (25mmol) of Dicyclohexylcarbodiimide (DCC) were added to the suspension in this order under ice bath, followed by stirring for 30 min. Then, 8.0g (25mmol) of D-Trp-OBzl was added. The reaction mixture was adjusted to pH 9 by dropwise addition of N-methylmorpholine (NMM). The reaction mixture was stirred first for 1h on ice and then for 12h at room temperature. The reaction mixture was filtered, the filtrate was concentrated under reduced pressure, and the residue was dissolved in 150mL of ethyl acetate solution. The ethyl acetate solution obtained was successively treated with 5% KHSO₄The aqueous solution was washed 3 times, and the saturated NaCl aqueous solution was washed 3 times. Anhydrous Na for ethyl acetate layer₂SO₄Drying for 12h, filtering, and concentrating the filtrate under reduced pressure to dryness. The resulting yellow syrup was purified by silica gel column Chromatography (CH)₂Cl₂/CH₃OH,100:1) 12.0g (88%) of the title compound are obtained as a colorless solid. ESI-MS (M/e):657[ M + H]⁺。

EXAMPLE 2 preparation of D-Lys (Cbz) -D-Trp-OBzl

3.8g (5mmol) D-Boc-Lys (Cbz) -D-Trp-OBzl were slowly mixed with 52mL of hydrogen chloride in ethyl acetate (4M) with stirring in an ice bath. The resulting solution was stirred in an ice bath for 5 h. After that, the reaction mixture was concentrated under reduced pressure. The residue was dissolved in 50mL of anhydrous ethyl acetate, and the resulting solution was concentrated under reduced pressure. This operation was repeated three times. The residue was washed thoroughly with anhydrous ether to give 3.41g (93%) of the title compound as a yellow powder. ESI-MS (M/e):557[ M + H ]]⁺。

EXAMPLE 3 preparation of (3R,6R) -3- (benzyloxycarbonylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (1)

3.45g (6.2mmol) of D-Boc-Lys (Cbz) -D-Trp-OBzl was dissolved in 150mL of ethyl acetate. After the resulting solution was washed three times with a 5% aqueous solution of sodium hydrogencarbonate, the ethyl acetate solution was stirred at room temperature for 12 hours to sufficiently precipitate a colorless solid. 1.8g (51%) of the title compound are filtered off. ESI-MS (M/e):449[ M + H ]]⁺。

EXAMPLE 4 preparation of (3R,6R) -3- (amino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (2)

To a solution of 1.9g (4.2mmol) of (3R,6R) -3- (benzyloxycarbonylamino-N-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (1) in 20mL of anhydrous N, N-Dimethylformamide (DMF) was added 200mg of Pd/C, and H was introduced₂The reaction was stirred at room temperature for 48 h. Pd/C was filtered off, and the filtrate was concentrated under reduced pressure to give 1.2g (92%) of the title compound as a colorless powder. ESI-MS (m/e): 315[ M + H ]]⁺EXAMPLE 5 preparation of amino-n-hexanoic acid methyl ester

5.6mL of thionyl chloride was added dropwise to 40mL of methanol, and after activation for 30min, 2.62g (20mmol) of aminohexanoic acid was added thereto and stirred at room temperature for 12 hours. Pumping the reaction solution under reduced pressure by using a water pump under stirring of the reaction compound in a 37 ℃ warm water bath, adding dry methanol for dissolving, then pumping the reaction solution under reduced pressure by using a water pump, and repeating the steps for 3 times; the suspension was suspended by adding anhydrous ether, and the mixture was dried under reduced pressure with stirring in a warm water bath at 37 ℃ and repeated 3 times to obtain 2.72g (95%) of the title compound. ESI-MS (M/e) 145[ M + H]⁺

EXAMPLE 6 preparation of Boc-Asp (OMe) -amino-n-hexanoic acid methyl ester (3a)

From 1330mg (5.0mmol) of Boc-aps (OMe) and 720mg (5.0mmol) of methyl aminohexanoate, 1320mg (91%) of the title compound was obtained as a colorless solid using the method of example 1. ESI-MS (M/e) 375[ M + H]⁺。

EXAMPLE 7 preparation of Boc-Glu (OMe) -amino-n-hexanoic acid methyl ester (3b)

The procedure of example 1 was used to obtain 1520mg (78%) of the title compound as a colorless solid from 1300mg (5.0mmol) of Boc-Glu (OMe) and 720mg (5.0mmol) of methyl aminohexanoate. ESI-MS (M/e):389[ M + H ]]⁺。

EXAMPLE 8 preparation of Boc-Asp (OMe) amino-n-hexanoic acid (4a)

1.11g (3.0mmol) Boc-Asp (OMe) -amino-n-hexanoic acid methyl ester (3a) was reacted with 20mL CH₃OH is dissolved. And adding NaOH aqueous solution (2M) into the obtained solution under the stirring of ice bath to adjust the pH value to 12, and stirring and reacting for 6 hours in ice bath. Stirring in ice bath, and reacting with saturated KHSO₄The pH value of the solution is adjusted to 7, and the obtained solution is concentrated under reduced pressure. The residue was treated with 5% KHSO₄Adjusting pH of the aqueous solution to 2. The resulting solution was extracted 3 times with ethyl acetate, and the ethyl acetate solution was washed with saturated aqueous NaCl solution to neutrality. Anhydrous Na for ethyl acetate layer₂SO₄Drying for 12h, filtering, and concentrating the filtrate under reduced pressure to dryness. 1.32g of the title compound are obtained as a pale yellow syrup. ESI-MS (M/e) 361[ M + H]⁺。

EXAMPLE 9 preparation of Boc-Glu (OMe) -amino-n-hexanoic acid (4b)

From 1.15g (3.0mmol) Boc-Glu (OMe) -amino-n-hexanoic acid methyl ester (3b) 1.38g of the title compound was obtained as light yellow syrup using the method of example 8. ESI-MS (M/e) 375[ M + H]⁺。

EXAMPLE 10 preparation of (3R,6R) -3- (Boc-Asp (OMe) -amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (5a)

From 1320mg of Boc-Asp (OMe) -amino-n-hexanoic acid (4a) and 940mg (3.0mmol) of (3R,6R) -3-amino-n-butyl-6- (indole-3-methyl) -piperazine-2, 5-dione (2) as pale yellow syrup, 700mg (36%) of the title compound were obtained using the method of example 1 as colorless solid. ESI-MS (M/e):655[ M + H]⁺；¹H NMR(300MHz,DMSO-d₆):δ/ppm＝10.882(s,1H),8.050(d,J＝1.8Hz,1H),7.940(d,J＝1.8Hz,1H),7.795(m,1H),7.573(m,2H),7.296(d,J＝8.1Hz,1H),7.032(m,3H),6.924(t,J＝7.2Hz,3H),4.258(m,1H),4.108(m,1H),3.571(m,3H),3.496(m,1H),3.246(dd,J₁＝14.1Hz,J₂＝3.9Hz,1H),3.004(m,3H),2.736(m,3H),1.988(t,J＝7.5Hz,1H),1.420(m,13H),1.166(m,2H),0.959(m,3H),0.565(m,3H)。

EXAMPLE 11 preparation of (3R,6R) -3- (Boc-Glu (OMe) -amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (5b)

From 1380mg of Boc-Glu (OMe) -amino-n-hexanoic acid (4b) in pale yellow syrup and 940mg (3.0mmol) (3R,6R) -3-amino-n-butyl-6- (indole-3-methyl) -piperazine-2, 5-dione (2) by the method of example 1, 440mg (22%) of the title compound were obtained as a colorless solid. ESI-MS (M/e):669[ M + H]⁺；¹H NMR(300MHz,DMSO-d₆):δ/ppm＝10.874(s,1H),8.035(m,2H),7.934(s,1H),7.796(m,1H),7.564(m,2H),7.302(m,1H),7.040(m,2H),6.941(t,J＝7.5Hz,1H),6.836(d,J＝8.4Hz,1H),4.114(m,1H),3.886(m,1H),3.581(s,3H),3.504(m,1H),3.255(dd,J₁＝14.4Hz,J₂＝3.9Hz,1H),3.032(m,3H),2.758(m,2H),2.297(t,J＝7.5Hz,2H),2.007(t,J＝7.2Hz,2H),1.850(m,1H),1.730(m,1H),1.378(m,13H),1.217(m,2H),0.972(m,3H),0.603(m,3H)。

EXAMPLE 12 preparation of (3R,6R) -3- (Boc-Asp-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (6a)

0.65g (1.0mmol) of (3R,6R) -3- (Boc-Asp (OMe) -amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (5a) was saponified as in example 11 to give 0.80g of a pale yellow syrup as the title compound. ESI-MS (M/e):641[ M + H]⁺。

EXAMPLE 13 preparation of (3R,6R) -3- (Boc-Glu-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (6b)

0.67g (1.0mmol) of (3R,6R) -3- (Boc-Glu (OMe) -amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (5b) was saponified as in example 11 to give 0.87g of a pale yellow syrup as the title compound. ESI-MS (M/e):655[ M + H]⁺。

EXAMPLE 14 preparation of (3R,6R) -3- (Asp-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (7a)

From 800mg of (3R,6R) -3- (Boc-Asp-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (6a) as pale yellow syrup, 80mg (15%) of the title compound were obtained as colorless solid according to the method of example 3. ESI-MS (M/e):543[ M + H]⁺；Mp:161–163℃；

(C＝0.1,H₂O)；¹H NMR(300MHz,DMSO-d₆):δ/ppm＝10.995(s,1H),8.274(m,1H),8.065(m,1H),7.963(s,1H),7.644(m,1H),7.576(d,J＝7.8Hz,1H),7.312(d,J＝7.5Hz,1H),7.044(m,3H),6.927(m,1H),4.115(m,1H),3.424(m,2H),3.043(m,4H),2.750(m,2H),2.405(m,1H),2.205(m,1H),2.016(m,2H),1.432(m,4H),1.239(m,3H),0.972(m,3H),0.590(m,3H)。

EXAMPLE 15 preparation of (3R,6R) -3- (Glu-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (7b)

From 870mg of (3R,6R) -3- (Boc-Glu-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (6b) as pale yellow syrup, 440mg (87%) of the title compound were obtained as colorless solid according to the method of example 3. ESI-MS (M/e):557[ M + H ]]⁺；Mp:141–143℃；

(C＝0.1,H₂O)；¹H NMR(300MHz,DMSO-d₆):δ/ppm＝10.968(s,1H),8.074(m,2H),7.962(s,1H),7.626(t,J＝5.1Hz,1H),7.571(d,J＝7.8Hz,1H),7.298(m,1H),7.028(m,2H),6.932(m,1H),4.108(m,1H),3.495(m,1H),3.296(m,1H),3.223(d,J＝3.9Hz,1H),3.029(m,4H),2.741(m,2H),2.241(t,J＝7.2Hz,2H),2.008(t,J＝7.2Hz,2H),1.772(m,2H),1.427(m,4H),1.217(m,3H),0.957(m,3H),0.586(m,3H)。

EXAMPLE 16 preparation of (3R,6R) -3- (Boc-aminocaproyl butylamino) -6- (indole-3-methyl) -piperazine-2, 5-dione (8)

From 0.97g (4.2mmol) Boc-aminocaproic acid and 1.9g (3.5mmol) (3R,6R) -3-butylamino-6- (indole-3-methyl) -piperazine-2, 5-dione (2) 0.641g (21%) of the title compound was obtained as a colorless solid using the method of example 1. ESI-MS (M/e):528[ M + H]⁺；¹H NMR(300MHz,DMSO-d₆):δ/ppm＝10.872(s,1H),8.035(d,J＝1.8Hz,1H),7.928(d,J＝1.8Hz,1H),7.560(m,2H),7.303(d,J＝5.7Hz,1H),7.034(m,2H),6.925(t,J＝7.5Hz,1H),6.763(t,J＝5.1Hz,1H),4.108(m,1H),3.499(m,1H),3.246(dd,J₁＝14.4Hz,J₂＝4.2Hz,1H),3.009(dd,J₁＝14.4Hz,J₂＝4.2Hz,1H),2.890(q,J＝6.6Hz,2H),2.750(q,J＝6.6Hz,2H),2.002(t,J＝7.2Hz,2H),1.465(m,2H),1.350(m,12H),1.205(m,3H),0.951(m,3H),0.553(m,3H)。

EXAMPLE 17 preparation of (3R,6R) -3- (aminocaproyl-butylamino) -6- (indole-3-methyl) -piperazine-2, 5-dione (9)

From 2.21g (4mmol) (3R,6R) -3- (Boc-aminocaproyl butylamino) -6- (indole-3-methyl) -piperazine-2, 5-dione (7) by the method of example 3, 1.45g were obtained(82%) the title compound as a colorless powder. ESI-MS (M/e):428[ M + H]⁺；¹H NMR(300MHz,DMSO-d₆):δ/ppm＝11.003(s,1H),8.086(s,1H),7.999(s,1H),7.748(s,1H),7.578(s,J＝8.1Hz,1H),7.314(m,J＝8.1Hz,1H),7.023(m,2H),6.926(m,1H),4.117(m,1H),3.502(m,1H),3.269(m,1H),3.041(m,1H),2.736(m,4H),2.030(m,2H),1.542(m,4H),1.260(m,2H),0.981(m,3H),0.590(m,3H)。

EXAMPLE 18 determination of the anti-tumor metastasis Activity of Compounds 7a, b

The assay model was inoculated with Lewis mouse lung carcinoma cells (LLC, purchased from ATCC) in DMEM medium (containing 10% inactivated fetal bovine serum, 1X 10)⁵U/L penicillin and 100mg/L streptomycin), and the cells are enriched by passage every two days according to an adherent cell culture method. Digesting the cells when the cells are in good growth state and in logarithmic growth phase, and adjusting the cell density to 1 × 10 with physiological saline⁷one/mL. Staining with placental blue to count viable cells>95 percent. Inbred C57BL/6 male mice (SPF grade, body weight 20. + -.2 g) were taken and left-handed mice fixed. The right anterior limb axillary skin of the mouse was disinfected with 75% ethanol. The LLC tumor cell suspension is injected subcutaneously into the axilla of a mouse with a 1mL sterile syringe held in the right hand, and 0.2mL is injected into each mouse. After the mice are inoculated for 10 days, tumors with the diameter of about 4-5mm grow out, namely the tumor source. The Lewis lung cancer tumor-bearing mice are inoculated for 10 days and anesthetized by ether, and then the cervical vertebrae are removed for killing.

Soaking in 75% ethanol for 10min, sterilizing, and removing tumor on clean bench. Well-grown tumor tissue was selected, minced in a sterile plate, and placed in a tissue homogenizer made of glass. Adding physiological saline with the temperature of 4 ℃ according to the ratio of the tumor mass to the volume of the physiological saline of 1 to 3(g to mL), and lightly grinding to prepare the cell suspension. The cell suspension is screened by 200-mesh cells to prepare single cell suspension. Adjusting the cell density of the single cell suspension to 1.5X 10 with physiological saline⁷one/mL. Staining with placental blue to count viable cells>95 percent. Left-handed inbred C57BL/6 male mice were fixed and their right anterior limb axillary skin was disinfected with 75% ethanol. The tumor cell suspension was injected subcutaneously into the mouse axilla with a 1mL sterile syringe in the right hand, 0.2mL each. 10 days after inoculation, mice developed tumors of 4-5mm in diameter, as measuredTumor volume inoculated mice were randomly grouped. Each group had 12 mice. On day 11 of tumor inoculation mice were orally administered either a recognized physiological saline solution of the anti-tumor metastasis peptide RGDS (dose of 20. mu. mol/kg/day) or a compound 7a, b (dose of 0.5. mu. mol/kg/day) or a compound 9 (dose of 5. mu. mol/kg/day) or an oral physiological saline (dose of 10 mL/kg/day) 1 dose per day for 12 consecutive days, and tumor volumes were measured and recorded every two days. The next day of the last administration, tumor volume was measured, cervical spine was removed by ether anesthesia and sacrificed, tumor of the mice was weighed, lung of the mice was taken and tumor nodules transferred from the lung of the tumor were counted. Statistical analysis of the data was performed using the t-test. The results are shown in Table 1. Compounds 7a, b were not only effective in inhibiting tumor lung metastasis at 0.5 μmol/kg dose, but also had no significant difference in activity from RGDS at 40-fold higher doses and compound 9 at 10-fold higher doses. These data indicate that the present invention has significant technical effects.

TABLE 1 antitumor metastatic Activity of Compounds 7a, b

a) P <0.01 to saline, p >0.05 to RGDS and compound 9; n is 11

EXAMPLE 19 determination of the anti-tumor growth Activity of Compounds 7a, b

Doxorubicin, compound 9 and compounds 7a, b were all dissolved in saline prior to assay for administration to S180 mice. Taking S180 ascites tumor liquid which is inoculated in a male ICR mouse and grows vigorously for 10 days in a sterile environment, diluting the S180 ascites tumor liquid into liquid (1:2) by using normal saline, fully mixing the liquid, dyeing the tumor cell suspension by using freshly prepared 0.2% trypan blue, uniformly mixing the liquid and the liquid, counting the liquid according to a white cell counting method, wherein the blue-dyed cell is a dead cell, and the non-dyed cell is a live cell. The cell concentration is 4-large-grid viable cell number/4 × 10⁴X dilution timesCell density was calculated as the number of cells/mL, and cell survival rate was calculated as the number of live cells/(number of live cells + number of dead cells) × 100%. Homogenizing tumor solution with survival rate of more than 90% to density of 2.0 × 10⁷Cell suspension per mL. This cell suspension was inoculated subcutaneously (0.2 mL/mouse) in the right axilla of a mouse to prepare S180 tumor-bearing mice. 24h after inoculation, S180 tumor-bearing mice were intraperitoneally injected daily with a saline solution of doxorubicin (dose 2. mu. mol/kg/day g) or daily orally administered with a saline solution of Compound 9 (dose 5. mu. mol/kg/day) or daily orally administered with a saline solution of Compounds 7a, b (dose 0.5. mu. mol/kg/day). The administration is once daily for 12 days. The day after the last dose, tumor volume was measured, cervical spine was removed under ether anesthesia and sacrificed, then the right axillary tumor growth site of the mouse was fixed with forceps, and the skin was excised and the tumor was blunt-stripped and weighed. Efficacy was expressed as tumor weight (mean ± SD g), and data were analyzed by t-test and variance. The results are shown in Table 2. Compounds 7a, b were not only effective at 0.5 μmol/kg dose in inhibiting tumor growth, but also had no significant difference in activity from compound 9, which was 10-fold higher than them at the dose. These data indicate that the present invention has significant technical effects.

TABLE 2 Effect of Compounds 7a, b on tumor growth in S180 mice

a) P <0.01 to saline, p >0.05 to compound 9; n is 12.

Claims

1. (3R,6R) -3- (AA-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione of the formula,

wherein AA is an L-Asp residue or an L-Glu residue.

2. A process for the preparation of (3R,6R) -3- (AA-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione of claim, which comprises:

(3) D-Lys (Cbz) -D-Trp-OBzl is dissolved in ethyl acetate, and the obtained solution is washed by a sodium bicarbonate solution containing 5 percent, and then cyclization is carried out to generate (3R,6R) -3- (benzyloxycarbonylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (1);

(5) condensing amino methyl hexanoate and Boc-AA to obtain Boc-AA-amino methyl hexanoate (3a, b);

(6) demethylating compound 3a, b to give Boc-aa (ome) -amino-n-hexanoic acid (4a, b);

(7) condensing the compound 2 and the compounds 4a and b to obtain (3R,6R) -3- (Boc-AA (OMe) -amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-diketone (5a and b);

(8) demethylating compound 5a, b to give (3R,6R) -3- (Boc-AA-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione (6a, b);

(9) and (3R,6R) -3- (AA-amino-n-hexanoyl-amino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-diketone (7a, b) is obtained by removing Boc from the compound 6a, b in the ethyl acetate solution of hydrogen chloride.

3. Use of (3R,6R) -3- (AA-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione according to claim 1 for the preparation of a medicament against lung cancer metastasis.

4. Use of (3R,6R) -3- (AA-amino-n-hexanoylamino-n-butyl) -6- (indole-3-methyl) -piperazine-2, 5-dione according to claim 1 for the preparation of a medicament against S180 ascites tumor.