The present invention relates to novel indole derivatives, to their preparation and to their use, as inhibitors of the enzyme poly(ADP-ribose)polymerase or PARP (EC 2.4.2.30), for producing drugs.
Poly(ADP-ribose)polymerase (PARP), or, as it is also termed, poly(ADP-ribose)synthase (PARS), is a regulatory enzyme which is found in cell nuclei (K. Ikai et al., J. Histochem. Cytochem. 1983, 31, 1261–1264). It is assumed that PARP plays a role in the repair of DNA breaks (M. S. Satoh et al., Nature 1992, 356, 356–358). Damage to, or breaks in, DNA strands activate the enzyme PARP which, when it is activated, catalyzes the transfer of ADP-ribose from NAD (S. Shaw, Adv. Radiat. Biol., 1984, 11, 1–69). In connection with this, nicotinamide is released from the NAD. The nicotinamide is converted once again, by other enzymes, into NAD with consumption of the energy carrier ATP. Accordingly, hyperactivation of PARP would result in an unphysiologically high consumption of ATP, with this leading, in the extreme case, to cell damage and cell death.
It is known that free radicals such as superoxide anion, NO and hydrogen peroxide, can give rise to DNA damage in cells and thereby activate PARP. Large quantities of free radicals are observed to be formed in a number of pathophysiological states, and it is assumed that this accumulation of free radicals leads or contributes to the observed cell or organ damage. While these pathophysiological states include, for example, ischemic states of organs as seen in association with stroke, cardiac infarction (C. Thiemermann et al., Proc. Natl. Acad. Sci. USA, 1997, 94, 679–683) or ischemia of the kidneys, they also include reperfusion damage as occurs, for example, after lysis of a cardiac infarction (see above: C. Thiemermann et al.). Consequently, inhibition of the enzyme PARP could be a means of at least partially preventing or alleviating this damage. Consequently, PARP inhibitors could represent a novel therapeutic principle for treating a number of diseases.
The enzyme PARP exerts an influence on the repair of DNA damage and could consequently also play a role in the therapy of cancer diseases since a higher potential effect on tumor tissue was observed in combination with cytostatically active substances (G. Chen et al. Cancer Chemo. Pharmacol. 1988, 22, 303).
Furthermore, it has been found that PARP inhibitors are able to exhibit an immunosuppressive effect (D. Weltin et al. Int. J. Immunopharmacol. 1995, 17, 265–271).
It has also been discovered that PARP is involved in immunological diseases or disorders in which the immune system plays an important role, such as rheumatoid arthritis and septic shock, and that PARP inhibitors are able to exhibit a favorable effect on the course of the disease (H. Kröger et al. Inflammation 1996, 20, 203–215; W. Ehrlich et al. Rheumatol. Int. 1995, 15, 171–172; C. Szabo et al., Proc. Natl. Acad. Sci. USA 1998, 95, 3867–3872; S. Cuzzocrea et al. Eur. J. Pharmacol. 1998, 342, 67–76).
Furthermore, the PARP inhibitor 3-aminobenzamide exhibited protective effects in a model of circulatory shock (S. Cuzzocrea et al., Br. J. Pharmacol. 1997, 121, 1065–1074).
There are also experimental indications that inhibitors of the enzyme PARP could be useful agents for treating diabetes mellitus (V. Burkart et al. Nature Med. 1999, 5, 314–319).
2-Phenylindoles have been described frequently in the organic synthesis literature. On the other hand, only a few examples are known which carry carboxylic acid derivatives in the 4 or 7 position. Thus, 2-phenylindoles containing a carboxylic acid or carboxylic ester function in the 4, 5 and 6 positions were described in Kasahara et al. J. Chem. Tech. Biotechnol. 1986, 36, 562–564 and Kasahara et al. J. Heterocyclic Chem. 1987, 24, 1555–1556. 2-Phenylindoles containing a 4- or 7-carboxamide function, which, however, carries additional alkyl or aryl substituents, were prepared in Oikawa et al. J. Org. Chem 1976, 41, 1118–1124. 7-Amido-2-phenylindoles which were additionally substituted on the indole were described in Black et al. Tetrahedron, 1994, 50, 10497–10508.
The compounds according to the invention of the general formulae I–II, which are dealt with in this present publication, have not been described previously and are consequently novel.
The present invention provides a compound of the formula I or II
where
—SO2—, —SO2NH—, —NHCO—, —CONH—, —NHSO2—, —NHCOCH2X4, and
Preferred is a compound of the formula I or II
wherein
Preferred is a compound of the formula I or II
wherein
In particular preferred is a compound of the formula I or II
wherein
The use of compounds of the general formulae I and II for producing drugs for treating neurodegenerative diseases and neuronal damage is also claimed, with R1, R2, R3 and X having the same meanings as given above and A is hydrogen.
The compounds of the formulae I, II can be employed as racemates, as enantiomerically pure compounds or as diastereomers. If enantiomerically pure compounds are desired, they can be obtained, for example, by carrying out a classical racemate resolution using a suitable optically active base or acid and the compounds of the formula I or their intermediates.
The present invention also relates to mesomeric or tautomeric compounds of the formulae I, II.
The present invention furthermore relates to physiologically tolerated salts of the compounds I, II which can be obtained by reacting compounds I, II with a suitable acid or base. Examples of suitable acids and bases are listed in Fortschritte der Arzneimittelforschung (Advances in Drug Research), 1966, Birkhäuser Verlag, Vol. 10, pp. 224–285. They include, for example, hydrochloric acid, citric acid, tartaric acid, lactic acid, phosphoric acid, methanesulfonic acid, acetic acid, formic acid, maleic acid, fumaric acid, etc., and sodium hydroxide, lithium hydroxide, potassium hydroxide and Tris.
Prodrugs are understood as being compounds which are metabolized in vivo into compounds of the general formulae I, II. Typical prodrugs are phosphates, carbamates of aminoacids, esters and other compounds.
The indole derivatives I, II according to the invention can be prepared in a variety of ways. Possible methods of synthesis follow those described in the above-listed literature references. Scheme 1 is intended to illustrate the synthesis strategy which is pursued in this connection.
Ester 1 is reacted with a styrene derivative in a palladium-catalyzed reaction. Where Y=NR2, the ring closure to form indole 3 takes place under aqueous/acid conditions. Where Y=H, the ring closure takes place after N-tosylation by palladium catalysis. The indole 3 is obtained by basic elimination of the N-tosyl group. The ester is reacted, at elevated temperatures, preferably from 80 to 130° C., with hydrazine in polar solvents such as the alcohols butanol and ethanol or else dimethylformamide. The hydrazide which accumulates in this connection is then reduced to the amide 4 under reductive conditions, such as using Raney nickel in alcohols under reflux.
The substituted indole derivatives I, II which are contained in the present invention are inhibitors of the enzyme poly(ADP-ribose)polymerase or PARP (EC 2.4.2.30).
The inhibitory effect of the substituted indole derivatives I, II was ascertained using an enzyme test which was already known in the literature, with a Ki value being determined as the measure of activity. In this way, the indole derivatives I, II were quantitatively tested for their inhibitory effect on the enzyme poly(ADP-ribose)polymerase or PARP (EC 2.4.2.30).
The substituted indole derivatives of the general formulae I, II are inhibitors of poly(ADP-ribose)polymerase (PARP) or, as it is also termed, poly(ADP-ribose)synthase (PARS) and can consequently be used for the treatment and prophylaxis of diseases which are linked to an increased activity of these enzymes.
The compounds of the formulae I, II can be employed for producing drugs for treating damage which occurs following ischemias and for prophylaxis where ischemias of various organs are expected.
Accordingly, the present indole derivatives of the general formulae I, II can be used for the treatment and prophylaxis of neurodegenerative diseases which occur following ischemia, trauma (craniocerebral trauma), hemorrhages, subarachnoidal bleeding and stroke, and of neurodegenerative diseases such as multiple infarct dementia, Alzheiner's disease and Huntington's disease, and of epilepsies, in particular of generalized epileptic attacks such as petit mal and tonic/clonic attacks and partial epileptic attacks, such as temporal lobe, and complex partial attacks, and, furthermore, for the treatment and prophylaxis of damage to the heart following cardiac ischemias and damage to the kidneys following renal ischemias, for example of acute kidney insufficiency, of acute kidney failure and of damage which occurs during and after a kidney transplant. Furthermore, the compounds of the general formulae I, II can be used for treating acute myocardial infarction and damage which occurs during and after its lysis by medical treatment (for example using TPA, Reteplase or Streptokinase or mechanically using a laser or rotablator), and of microinfarctions during and after heart valve replacement, aneurysm resections and heart transplants The present indole derivatives I, II can likewise be used for treating revascularization of critically stenosed coronary arteries, for example in PCTA and bypass operations, and critically stenosed peripheral arteries, for example arteries of the leg. Furthermore, the indole derivatives I, II can be of use in the chemotherapy of tumors and their metastasization and be used for treating inflammations and rheumatic diseases, for example rheumatoid arthritis, and also for treating diabetes mellitus.
The drug preparations according to the invention contain a therapeutically effective quantity of the compounds I, II in addition to the customary pharmaceutical adjuvants.
For local external use, for example in powders, ointments or sprays, the active compounds can be present at the customary concentrations. As a rule, the active compounds are present in a quantity of from 0.001 to 1% by weight, preferably of from 0.001 to 0.1% by weight.
For internal use, the preparations are administered in individual doses. In an individual dose, from 0.1 to 100 mg is/are administered per kg of body weight. The preparations may be administered daily in one or more doses, depending on the nature and severity of the diseases.
In addition to the active compound, the drug preparations according to the invention comprise the customary excipients and diluents which correspond to the desired mode of administration. For local external use, it is possible to employ adjuvants which are customary in pharmaceutical technology, such as ethanol, isopropanol, ethoxylated castor oil, ethoxylated hydrated castor oil, polyacrylic acid, polyethylene glycol, polyethylene glycostearate, ethoxylated fatty alcohols, paraffin oil, vaseline and lanolin. Lactose, propylene glycol, ethanol, starch, talc and polyvinylpyrrolidone are, for example, suitable for internal use.
Furthermore the preparations can comprise antioxidants such as tocopherol and butylated hydroxyanisole and also butylated hydroxytoluene, taste-improving additives, stabilizers, emulsifiers and glidants.
The substances which the preparation contains in addition to the active compound, and also the substances employed in producing the pharmaceutical preparations, are toxicologically harmless and compatible with the relevant active compound. The drug preparations are produced in a customary manner, for example by mixing the active compound with other customary excipients and diluents.
The drug preparations may be administered in a variety of modes of administration, for example perorally, parenterally, such as intravenously by infusion, subcutaneously, intraperitoneally and topically. Thus, possible preparation forms are tablets, emulsions, infusion solutions, injection solutions, pastes, ointments, gels, creams, lotions, powders and sprays.
A 96-well microtiter plate (Falcon) is coated with histones (type II-AS; SIGMA H7755). For this, histones are dissolved up to a concentration of 50 μg/ml in carbonate buffer (0.05 M NaHCO3; pH 9.4). The individual wells of the microtiter plate are incubated overnight with in each case 100 μl of this histone solution. The histone solution is then removed and the individual wells are incubated, at room temperature, with 200 μl of a 1% BSA (bovine serum albumin) solution in carbonate buffer for 2 hours. The plate is then washed three times with washing buffer (0.05% Tween10 in PBS). For the enzyme reaction, 50 μl of the enzyme reaction solution (5 μl of reaction buffer (1M Tris-HCl, pH 8.0, 100 mM MgCl2, 10 mM DTT), 0.5 μl of PARP (c=0.22 μg/μl), 4 μl of activated DNA (SIGMA D-4522, 1 mg/ml in water), 40.5 μl of H2O) are preincubated, in each well, for 10 minutes with 10 μl of an inhibitor solution. The enzyme reaction is started by adding 40 μl of a substrate solution (4 μl of reaction buffer (see above), 8 μl of NAD solution (100 μM in H2O), 28 μl of H2O). The reaction time is 20 minutes at room temperature. The reaction is stopped by washing three times with washing buffer (see above). There then follows a one-hour incubation at room temperature, during which time the plate is incubated with a specific anti-poly-ADP-ribose antibody. The antibody employed was a monoclonal “10OH” anti-poly(ADP-ribose) antibody (Kawamaitsu H et al. (1984) Monoclonal antibodies to poly (adenosine diphosphate ribose) recognize different structures. Biochemistry 23, 3771–3777) Polyclonal antibodies can be used in exactly the same way.
The antibodies were used in a 1:5000 dilution in antibody buffer (1% BSA in PBS; 0.05% Tween20). After the plate has been washed three times with washing buffer, there then follows a one-hour incubation at room temperature with the secondary antibody. In this case, use was made, for the monoclonal antibody, of an antimouse IgG coupled to peroxidase (Boehringer Mannheim) and, for the rabbit antibody, of an anti-rabbit IgG coupled to peroxidase (SIGMA A-6154), with each of these secondary antibodies being used in a 1:10000 dilution in antibody buffer. After the plate has been washed three times with washing buffer, the color reaction is effected using 100 μl of color reagent (SIGMA, TMB Readymix, T8540)/well at room temperature for approx. 15 min. The color reaction is stopped by adding 100 μl of 2M H2SO4. A measurement is then taken immediately (450 nm against 620 nm; “Easy Reader” ELISA plate reading appliance EAR340AT, SLT Labinstruments, Austria). The IC50 value of an inhibitor under measurement is the concentration of the inhibitor at which the change in color concentration is half the maximum.
The following compounds according to the invention can be prepared using the above-described methods:
The present invention also relates to substituted indole derivatives of the general formulae Ia and IIa
where
Preference is given to compounds of the formulae Ia and IIa where
Preference is given to compounds of the formulae Ia and IIa where
Particular preference is given to compounds of the formulae Ia and IIa where
The use of compounds of the general formulae Ia and IIa for producing drugs for treating neurodegenerative diseases and neuronal damage is also claimed, with R1, R2, R3 and X having the same meanings as above and with it being possible for A to be hydrogen or a C1–C6 alkyl chain.
The compounds of the formulae Ia, IIa can be employed as racemates, as enantiomerically pure compounds or as diastereomers. If enantiomerically pure compounds are desired, they can be obtained, for example, by carrying out a classical racemate resolution using a suitable optically active base or acid and the compounds of the formula I or their intermediates.
The present invention also relates to mesomeric or tautomeric compounds of the formulae Ia, IIa.
The present invention furthermore relates to physiologically tolerated salts of the compounds Ia, IIa which can be obtained by reacting compounds Ia, IIa with a suitable acid or base. Examples of suitable acids and bases are listed in Fortschritte der Arzneimittelforschung (Advances in Drug Research), 1966, Birkhäuser Verlag, Vol. 10, pp. 224–285. They include, for example, hydrochloric acid, citric acid, tartaric acid, lactic acid, phosphoric acid, methanesulfonic acid, acetic acid, formic acid, maleic acid, fumaric acid, etc., and sodium hydroxide, lithium hydroxide, potassium hydroxide and Tris.
Prodrugs are understood as being compounds which are metabolized in vivo into compounds of the general formulae Ia, IIa. Typical prodrugs are phosphates, carbamates of aminoacids, esters and other compounds.
The indole derivatives Ia, IIa according to the invention can be prepared in a variety of ways. Possible methods of synthesis follow those described in the above-listed literature references. Scheme 2 is intended to illustrate the synthesis strategy which is pursued in this connection.
Ester 1 is reacted with a styrene derivative in a palladium-catalyzed reaction. Where Y=NR2, the ring closure to form indole 3 takes place under aqueous/acid conditions Where Y=H, the ring closure takes place after N-tosylation by palladium catalysis. The indole 3 is obtained by basic elimination of the N-tosyl group. The ester is reacted, at elevated temperatures, preferably from 80 to 130° C., with hydrazine in polar solvents such as the alcohols butanol and ethanol or else dimethylformamide. The hydrazide which accumulates in this connection is then reduced to the amide 4 under reductive conditions, such as using Raney nickel in alcohols under reflux.
The substituted indole derivatives which are contained in the present invention are inhibitors of the enzyme poly(ADP-ribose)polymerase or PARP (EC 2.4.2.30).
The inhibitory effect of the substituted indole derivatives Ia, IIa was ascertained using an enzyme test which was already known in the literature, with a Ki value being determined as the measure of activity. In this way, the indole derivatives I–IV were quantitatively tested for their inhibitory effect on the enzyme poly(ADP-ribose)polymerase or PARP (EC 2.4.2.30).
The substituted indole derivatives of the general formulae I–IV are inhibitors of poly(ADP-ribose)polymerase (PARP) or, as it is also termed, poly(ADP-ribose)synthase (PARS) and can consequently be used for the treatment and prophylaxis of diseases which are linked to an increased activity of these enzymes.
The compounds of the formulae Ia, IIa can be employed for producing drugs for treating damage which occurs following ischemias and for prophylaxis where ischemias of various organs are expected.
Accordingly, the present indole derivatives of the general formulae Ia, IIa can be used for the treatment and prophylaxis of neurodegenerative diseases which occur following ischemia, trauma (craniocerebral trauma), hemorrhages, subarachnoidal bleeding and stroke, and of neurodegenerative diseases such as multiple infarct dementia, Alzheimer's disease and Huntington's disease, and of epilepsies, in particular of generalized epileptic attacks such as petit mal and tonic/clonic attacks and partial epileptic attacks, such as temporal lobe, and complex partial attacks, and, furthermore, for the treatment and prophylaxis of damage to the heart following cardiac ischemias and damage to the kidneys following renal ischemias, for example of acute kidney insufficiency, of acute kidney failure and of damage which occurs during and after a kidney transplant. Furthermore, the compounds of the general formulae Ia, IIa can be used for treating acute myocardial infarction and damage which occurs during and after its lysis by medical treatment (for example using TPA, Reteplase or Streptokinase or mechanically using a laser or rotablator), and of microinfarctions during and after heart valve replacement, aneurysm resections and heart transplants. The present indole derivatives Ia, IIa can likewise be used for treating revascularization of critically stenosed coronary arteries, for example in PCTA and bypass operations, and critically stenosed peripheral arteries, for example arteries of the leg. Furthermore, the indole derivatives Ia, IIa can be of use in the chemotherapy of tumors and their metastasization and be used for treating inflammations and rheumatic diseases, for example rheumatoid arthritis, and also for treating diabetes mellitus.
The drug preparations according to the invention contain a therapeutically effective quantity of the compounds Ia, IIa in addition to the customary pharmaceutical adjuvants.
For local external use, for example in powders, ointments or sprays, the active compounds can be present at the customary concentrations. As a rule, the active compounds are present in a quantity of from 0.001 to 1% by weight, preferably of from 0.001 to 0.1% by weight.
For internal use, the preparations are administered in individual doses. In an individual dose, from 0.1 to 100 mg is/are administered per kg of body weight. The preparations may be administered daily in one or more doses, depending on the nature and severity of the diseases.
In addition to the active compound, the drug preparations according to the invention comprise the customary excipients and diluents which correspond to the desired mode of administration. For local external use, it is possible to employ adjuvants which are customary in pharmaceutical technology, such as ethanol, isopropanol, ethoxylated castor oil, ethoxylated hydrated castor oil, polyacrylic acid, polyethylene glycol, polyethylene glycostearate, ethoxylated fatty alcohols, paraffin oil, vaseline and lanolin. Lactose, propylene glycol, ethanol, starch, talc and polyvinylpyrrolidone are, for example, suitable for internal use.
Furthermore the preparations can comprise antioxidants such as tocopherol and butylated hydroxyanisole and also butylated hydroxytoluene, taste-improving additives, stabilizers, emulsifiers and glidants.
The substances which the preparation contains in addition to the active compound, and also the substances employed in producing the pharmaceutical preparations, are toxicologically harmless and compatible with the relevant active compound. The drug preparations are produced in a customary manner, for example by mixing the active compound with other customary excipients and diluents.
The drug preparations may be administered in a variety of modes of administration, for example perorally, parenterally, such as intravenously by infusion, subcutaneously, intraperitoneally and topically. Thus, possible preparation forms are tablets, emulsions, infusion solutions, injection solutions, pastes, ointments, gels, creams, lotions, powders and sprays.
A 96-well microtiter plate (Falcon) is coated with histones (type II-AS; SIGMA H7755). For this, histones are dissolved up to a concentration of 50 μg/ml in carbonate buffer (0.05 M NaHCO3; pH 9.4). The individual wells of the microtiter plate are incubated overnight with in each case 100 μl of this histone solution. The histone solution is then removed and the individual wells are incubated, at room temperature, with 200 μl of a 1% BSA (bovine serum albumin) solution in carbonate buffer for 2 hours. The plate is then washed three times with washing buffer (0.05% Tween10 in PBS). For the enzyme reaction, 50 μl of the enzyme reaction solution (5 μl of reaction buffer (1M Tris-HCl, pH 8.0, 100 mM MgCl2, 10 mM DTT), 0.5 μl of PARP (c=0.22 μg/μl), 4 μl of activated DNA (SIGMA D-4522, 1 mg/ml in water), 40.5 μl of H2O) are preincubated, in each well, for 10 minutes with 10 μl of an inhibitor solution. The enzyme reaction is started by adding 40 μl of a substrate solution (4 μl of reaction buffer (see above), 8 μl of NAD solution (100 μM in H2O), 28 μl of H2O). The reaction time is 20 minutes at room temperature The reaction is stopped by washing three times with washing buffer (see above). There then follows a one-hour incubation at room temperature, during which time the plate is incubated with a specific anti-poly-ADP-ribose antibody. The antibody employed was a monoclonal “10H”, anti-poly(ADP-ribose) antibody (Kawamaitsu H et al. (1984) Monoclonal antibodies to poly (adenosine diphosphate ribose) recognize different structures. Biochemistry 23, 3771–3777). Polyclonal antibodies can be used in exactly the same way.
The antibodies were used in a 1:5000 dilution in antibody buffer (1% BSA in PBS; 0.05% Tween20). After the plate has been washed three times with washing buffer, there then follows a one-hour incubation at room temperature with the secondary antibody. In this case, use was made, for the monoclonal antibody, of an anti-mouse IgG coupled to peroxidase (Boehringer Mannheim) and, for the rabbit antibody, of an anti-rabbit IgG coupled to peroxidase (SIGMA A-6154), with each of these secondary antibodies being used in a 1:10000 dilution in antibody buffer. After the plate has been washed three times with washing buffer, the color reaction is effected using 100 μl of color reagent (SIGMA, TMB Readymix, T8540)/well at room temperature for approx. 15 min. The color reaction is stopped by adding 100 μl of 2M H2SO4. A measurement is then taken immediately (450 nm against 620 nm; “Easy Reader” ELISA plate reading appliance EAR340AT, SLT Labinstruments, Austria). The IC50 value of an inhibitor under measurement is the concentration of the inhibitor at which the change in color concentration is half the maximum.
The following compounds according to the invention can be prepared using the above-described methods:
Number | Date | Country | Kind |
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100 22 925 | May 2000 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP01/05278 | 5/9/2001 | WO | 00 | 10/6/2003 |
Publishing Document | Publishing Date | Country | Kind |
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WO01/85687 | 11/15/2001 | WO | A |
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20040067949 A1 | Apr 2004 | US |