JPH07278146A - Benzylguanine derivative - Google Patents

Abstract

PURPOSE:To obtain a new derivative inhibiting the action of a repair enzyme O<6>-methylguanine DNA methyltransferase and effective as an effect enhancer for alkylated type anticancer agents. CONSTITUTION:This derivative is O<6>-(p-Methoxybenzyl)guanine of the formula. The derivative is obtained by reacting 2-amino-6-chloropurine with the corresponding p-methoxybenzyl alcohol in the presence of sodium under heating (preferably at 50-150 deg.C) for 10-50hr and can be purified by column chromatography, etc.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel benzylguanine derivative, which inhibits the action of the repair enzyme O ⁶ -methylguanine DNA methyltransferase, and is therefore effective as an effect enhancer for alkylated anticancer agents. And can be used in the pharmaceutical industry.

[0002]

2. Description of the Related Art O ⁶ -methylguanine DNA methyltransferase (hereinafter referred to as MGMT) receives a methyl group from O ⁶ -methylguanine generated in DNA and loses its enzymatic activity, but has a methylated guanine. DN
It is known as an enzyme that efficiently regenerates and repairs guanine without changing the basic structure of A. In addition, MGMT is an alkyl group such as N '-[(4-amino-2-methyl-5-pyrimidinyl) methyl] -N- (2-chloroethyl) -N-nitrosourea (hereinafter referred to as ACNU) because of its properties. It is also known to reduce the cytocidal effect of chemotherapeutic anticancer agents. On the other hand, it has been found that treatment of cells with O ⁶ -methylguanine, which is a substrate of MGMT, can enhance the activity of ACNU. Recently, anthony peg and the like have reported that O ⁶ -benzylguanine or derivatives thereof. Have more effectively inhibited the activity of MGMT (J. Med. Chem. 1992, 35, 4486-4491).

[0003]

Based on these findings, the present inventors have investigated various O ⁶ -benzylguanine derivatives, and have found that they can inhibit the activity of MGMT more effectively and, therefore, that of alkylated anticancer agents. An object of the present invention is to provide a novel compound which can be a more excellent enhancer.

[0004]

As a result of research, the present inventors have found that some novel O ⁶ -benzylguanine derivatives satisfy the above characteristics, and have completed the present invention. That is, the present invention relates to a benzylguanine derivative represented by the following structural formula (1).

[0005]

[Chemical 2]

The present invention will be described in detail below. The O ⁶ -benzylguanine derivative of the present invention can be easily synthesized according to the method already reported, that is, by the alkoxylation reaction of 2-amino-6-chloropurine. More specifically, it can be obtained by reacting 2-amino-6-chloropurine with the corresponding p-methoxybenzyl alcohol in the presence of sodium under heating, preferably at 50 ° C to 150 ° C for 10 hours to 50 hours. The product can be purified by conventional means such as column chromatography.

[0007]

The O ⁶ -benzylguanine derivative of the present invention is MG
It shows the action of inhibiting the activity of MT and enhancing the cell killing effect of the alkylated anticancer drug.

[0008]

【Example】

Preparation of derivative O ^6- (p-methoxybenzyl) guanine (compound of structural formula 1) 270 mg (11.7 mmol) of sodium metal was dissolved in 10 ml of p-methoxybenzyl alcohol. 2-in this solution
Amino-6-chloropurine 1000 mg (5.9 mmol) was added with stirring. The reaction solution was heated to 130 ° C. and left overnight. After cooling, it was neutralized with acetic acid. 1000 ml of diethyl ether was added to the reaction solution with vigorous stirring. After suction filtration, the residue was collected and recrystallized from methanol to obtain 320 mg (20 mg) of O ^6- (p-methoxybenzyl) guanine as white needle crystals.
%). The characteristic values measured were as follows. Melting point: 346-348 ° C (decomposition) UV λ max nm (ε) in MeOH 282 (12000), 241 (sh) (1200
0) MS m / z 271 (M ⁺ ). ¹ H-NMR (Me ₂ SO-d ₆ ) δ: 3.63 (s, 3H, CH ₃ ), 5.42 (s, 2
H, CH ₂ ), 6.25 (s, 2H, NH ₂ ), 6.95 (d, 2H, ph, J = 8.5Hz), 7.46
(d, 2H, ph), 7.79 (s, 1H, 8-H), 12.44 (s, 1H, 8-H)

Characteristic Evaluation of Derivatives ACNU was selected as an alkylated anticancer agent, and the effect on the cell killing effect of the alkylated anticancer agent was measured using each derivative obtained above by a spectroscope using the MTT method as follows. did. HeLa S3 (derived from human cervical cancer) and C6-1 (derived from rat glioma) were placed on a micro test plate with 1.00
0 cells / 90 μL medium was inoculated. The cells were cultured for 2 hours with or without addition of 10 μL of the derivative. Pre-treated cells were added to various concentrations of 11 μl (final concentration 0-100 μm).
After adding ACNU of M), the cells were cultured for 2 hours. After culturing, the medium was removed, the cells were washed twice with PBS, suspended in 100 μL of fresh medium, and cultivated for 5 days, then 570
Viable cells were weighed by measuring the absorbance at nm to compare the effects of the derivatives.

A part of the measurement results is shown in Table 1. The values in Table 1 are 30 μM of A in cells treated with 10 μM of the derivative.
Viable cell rate when CNU was added and 30% for untreated cells
This is a comparison of the viable cell rates when μM ACNU was added, and the numerical values were calculated as follows. Enhancement effect = number of viable cells when untreated / number of viable cells when treated

[0011]

[Table 1] 6-MeOBzlG: O ^6- (p-methoxybenzyl) guanine

[0012]

INDUSTRIAL APPLICABILITY The present invention has an excellent effect that it can provide an enzyme activity inhibitor of O ⁶ -methylguanine DNA methyltransferase and an enhancer of an alkylated anticancer agent.

[Brief description of drawings]

FIG. 1 is a graph of O ^6- (p-methoxybenzyl) guanine
It is a figure which shows a ¹ H-NMR spectrum.

FIG. 2 shows that of O ^6- (p-methoxybenzyl) guanine
It is a figure which shows a UV spectrum. The measurement is in methanol.

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Claims (1)

[Claims] 1. A benzylguanine derivative represented by the following structural formula (1). [Chemical 1]