WO2013136296A2

WO2013136296A2 - Water-soluble organometallic ruthenium and iron compunds presenting heteroaromatic ligands

Info

Publication number: WO2013136296A2
Application number: PCT/IB2013/052035
Authority: WO
Inventors: Maria Helena ANSELMO VIEGAS GARCIA; Tânia Sofia FERREIRA MORAIS; Ana Isabel ANTUNES TOMAZ DINIZ; Fernanda MARUJO MARQUES
Original assignee: Universidade De Lisboa
Priority date: 2012-03-14
Filing date: 2013-03-14
Publication date: 2013-09-19
Also published as: WO2013136296A3

Abstract

The present invention relates to new water soluble organometallic ruthenium and iron complexes comprising a diphenylphosphane-benzene-3-sulfonate phosphane and a heteroaromatic ligand bound directly to the metal center, as well as its preparation procedure. The new compounds can be obtained by three methods depending on the starting materials. The invention reports a great variety of complexes to be produced by combining several compounds which bind to metal centers. The new compounds can be used in the treatment or prevention of tumors and tumor metastasis.

Description

DESCRIPTION

WATER-SOLUBLE ORGANOMETALLIC RUTHENIUM AND IRON COMPOUNDS

PRESENTING HETEROAROMATIC LIGANDS"

The present invention relates to new water soluble organometallic ruthenium and iron complexes comprising a diphenylphosphane-benzene-3-sulfonate phosphane and a heteroaromatic ligand bound directly to the metal center, as well as its preparation procedure. The new compounds can be obtained by three methods depending on the starting materials. The invention reports a great variety of complexes to be produced by combining several compounds which bind to metal centers.

The family of ruthenium or iron compounds that is subject of the present invention shows great potential as pharmaceutical agents for the treatment of cancer conditions. In fact, the present compounds enlarge a general family of ruthenium or iron organometallic compounds showing very high efficiency in vitro against a wide range of human tumor cells, significantly surpassing the activity of the benchmark metallodrug cisplatin currently in clinical use. Importantly, the controlled hydrophilicity that the phosphane ligands can impart to these compounds can be a crucial characteristic for the efficiency of administration of these compounds as metallodrugs .

Background of the invention

It has been reported in the literature that ruthenium-based compounds can play a significant role as antitumoral agents, and may become an important alternative to metallodrug chemotherapy overcoming part, if not most, of the problems related to treatments with cisplatin and drugs alike approved for clinical use worldwide. The most important difficulties associated with platinum-based drugs in chemotherapy are their inactivity against many cancer conditions and against tumor metastasis, the development of resistance to treatment and several undesirable severe side-effects .

In fact, the undesirable side-effects of cisplatin drugs, its inactivity against many cancer tumors and metastasis (T.M. Klapotke et. al . , Organometallics , 13 (1994) 3628- 3633) together with the problem derived of drug resistance, have been stimulating the search for new effective alternatives in the field of non-platinum-based anticancer drugs (M.J. Clarke et. al . , Chem. Rev. 99 (1999) 2511-2534; C.X. Zhang et. al . , Curr. Opin. Chem. Biol. 7 (2003) 481- 489; M. Galanski, et. al.,Curr. Pharm. Des. 9 (2003) 2078- 2089) .

The urgency to overcome these drawbacks has stimulated the search for new effective agents.

Optically resolved enantiomers of ruthenium (II) and Co (II) and 1, 10-phenanthroline derivatives, with the structure R₃M, are disclosed in US 4980473 (1990) to be useful for the treatment of tumor cells in a subject.

Antitumor activity have been reported for some other ruthenium ( I I ) and ruthenium ( I I I ) complexes such as trans-

[RuCl₂ (DMSO) ₄] , [ImH] [trans-RuCl₄ (DMSO) Im] , [ImH] [trans- RuCl₄lm₂] (Im = imidazole) and (Hind) [ trans-RuCl₄ ( ind) 2 ] ,

(ind=indazole) (C.G. Hartinger et. al . , J. Inorg. Biochem. 100 (2006) 891-904; S. Kapitza, et. Al . , J. Cancer Res. Clin. Oncol. 131 (2005) 101-110; M.A. Jakupec, et. al . , Int. J. Clin. Pharm. Ther. 43 (2005) 595-602.

U.S. Pat. No. 4,980,473 discloses 1, 10-phenanthroline complexes of ruthenium ( I I ) and cobalt (II) which are reported to be useful for the treatment of tumour cells in a subject.

Other ruthenium ( I I ) and ruthenium ( I I I ) complexes which have been shown to exhibit antitumour activity are mentioned in Guo et al . , Inorganica Chimica Acta, 273 (1998), 1-7, specifically trans- [RuCl2 (DMSO) 4] , trans- [RUCI4 (imidazole) 2] and trans- [RUCI4 (indazole) 2] ·

Dale et al . , Anti-Cancer Drug Design, (1992), 7, 3-14, describe a metronidazole complex of ruthenium ( I I ) i.e., [ ( C eiie ) RUCI2 (metronidazole) ] and its effect on DNA and on E. coli growth rates. Metronidazole sensitizes hypoxic tumour cells to radiation and appears to be an essential element of the complexes of Dale et al .. There is no indication that the complexes would be at all effective in the absence of the metronidazole ligand.

WO 01/130790 discloses ruthenium ( I I ) compounds and their use as anticancer agents. The compounds have neutral N- donor ligands and the resulting ruthenium complexes are generally positively charged.

WO 02/102572 also discloses ruthenium ( I I ) compounds, generally positively charged, containing a bidentate neutral diamine ligand that have activity against cancer cell lines. WO 06/018649, US 2006/0058270, US 2005/0239765, US 2009/0312301 Al relate to organometallic compounds useful in the treatment of metastasis, comprising a ligand that is covalently bound to a bioactive compound. These compounds are inhibitors of a resistance pathway.

The present invention refers to the use of a family of water soluble organometallic ruthenium and iron compounds presenting a half sandwich "piano-stool" structure with potential application as anticancer agents.

The main feature of the present compounds is based on the possibility of controlled water solubility depending on the phosphanes present in the metal ion coordination sphere. Moreover, new iron derivatives, here presented, are a potential family of compounds with promising activity against tumor cells.

Summary of the invention

The present invention relates to new water soluble organometallic ruthenium and iron complexes comprising a diphenylphosphane-benzene-3-sulfonate phosphane and a heteroaromatic ligand bound directly to the metal center, as well as its preparation procedure.

A preferred embodiment of the present invention provides a water-soluble organometallic ruthenium and/or iron compounds or their pharmaceutically acceptable salts or optically resolved enantiomers of general formula

(I)

wherein,

M is a ruthenium or iron atom; R represents a biomolecule (for example aminoacid, peptide, oligopeptide, protein, protein fragment, stradiol, etc.) or a heteroatomatic ligand, or a bioactive organic compound or a radical -Rl, - R1-NH2, -R1-C00H, -R1-COO-, - Rl-OH, -R1-COONCH3, where Rl is nan alkyl or aryl group; LI and L2 comprise the following arangments:

LI is a diphenylphosphane-benzene-3-sulfonate or any other monodentate water-soluble phosphane or any other phosphane ligand, and

L2 is a monodentate heteroaromatic compound with a single or a multiring system in which one of the rings contains one heteroatom chosen from the group N, 0, S, Se or P; or

LI and L2 represent a bidentate heteroaromatic compound composed by a single or a multiring system in which one or two of the rings contain one heteroatom chosen from the group N, 0, S, Se or P. In another embodiment of the present invention, the process for the preparation of the compounds described above comprises :

i) Replacement of one or two triphenylphosphanes in the complex [M(CpR) (PPh3)2 ] by one or two diphenylphosphane-benzene-3-sulfonates or by one diphenylphosphane-benzene-3-sulfonate and other different water soluble phosphane or any other type of phosphane, (M=Ru, Fe; X=C1, I; CpR is a cyclopentadienyl derivative wherein R represents a biomolecule (for example aminoacid, peptide, oligopeptide, protein, protein fragment, stradiol, etc.) or a heteroatomatic ligand, or a bioactive organic compound or a radical -Rl, -R1-NH2, -Rl-COOH, -R1-COO-, - Rl-OH, -R1-COONCH3, where Rl is an alkyl or aryl group) , and;

ii) reaction of compound of step i) with a heteroaromatic ligand .

A preferred embodiment of the present invention provides, the above described process wherein the reaction temperature is from -60°C to 300°C and the pressure is from 0,5 atm to 100 atm.

In another embodiment of the present invention, the process for the preparation of the compounds described above, comprises :

i) direct reaction of a ruthenium or iron salts of general formula MX3, wherein X is halide, nitrite, phosphate, perchlorate or carbonate, with a cyclopentadienyl derivative, diphenylphosphane- benzene-3-sulfonate and soluble phosphanes (equal or different) or mixture of diphenylphosphane-benzene-3- sulfonate and other phosphanes, and

ii) reaction of compound obtained in step i) with a heteroaromatic ligand.

In another embodiment of the present invention, the process for the preparation of the compounds described above, comprises a direct reaction of a ruthenium and/or iron salts of general formula MX₃, wherein X is halide, nitrite, phosphate, perchlorate or carbonate, with a cyclopentadienyl derivative, one or two diphenylphosphane- benzene-3-sulfonate or diphenylphosphane-benzene-3- sulfonate and soluble phosphanes (equal or different) or mixture of diphenylphosphane-benzene-3-sulfonate and other phosphanes, and a heteroaromatic ligand.

In another embodiment of the present invention, the water- soluble organometallic ruthenium and/or iron compound or their pharmaceutically acceptable salts or optically resolved enantiomers are used for the treatment and/or prevention of tumors and/or tumor metastasis. Detailed description of the invention

The present invention relates to new water soluble organometallic ruthenium and iron complexes comprising a diphenylphosphane-benzene-3-sulfonate phosphane and a heteroaromatic ligand directly bounded to the metal center, as well as its preparation procedure.

These compounds combine antitumor properties with water solubility and air stability. These characteristics are desirable and thus an advantage for drugs derived from these compounds, since they allow a much easier formulation, conservation and administration of the drug. In addition, the high cytotoxic activity showed by these compounds is complemented by a high specificity against different tumors, which depends on the structure of each compound. The high efficiency and selectivity of these compounds is related to their low toxicity against healthy cells .

The present invention relates to water-soluble ruthenium/iron complexes comprising cyclopentadienyl derivatives, phosphanes and heteroatomatic ligands with general formula:

(I)

Where: M is a ruthenium or/and iron atom; R represents a biomolecule (for example aminoacid, peptide, oligopeptide, protein, protein fragment, stradiol, etc.) or a heteroatomatic ligand, or a bioactive organic compound or a radical -Rl, -R1-NH₂, -Rl-COOH, -R1-COO-, - Rl-OH, -Rl- COONCH₃, where Rl is an alkyl or aryl group; LI and L2 can be arranged comprising:

1) LI is a diphenylphosphane-benzene-3-sulfonate or any other monodentate water-soluble phosphane or any other phosphane ligand; and L2 is a monodentate heteroaromatic compound constituted by a single or a multiring system in which one of the rings bears ate least one heteroatom such as N, 0, S, Se, P, etc;

2) LI and L2 represent a bidentate heteroatomatic compound composed by a single or a multiring system in which one or two of the rings bear at least one heteroatom such as N, 0, S, Se, P, etc. that guarantee the coordination to the metal center.

The ruthenium or iron atom has cytotoxic activity against tumour cells when coordinated to phosphane ligands. The preferential formulation of the present invention is considered to be ruthenium or iron complexes of general formula (I), in which the phosphane ligands contain sulfonate, phosphate, carbonate, amines, ammonium, carboxylate, alcohol and aldehyde groups and/or mixtures of these. The term "mixture" is intended to refer the phosphanes possessing one or more of the functional groups described above for the purpose of the present invention.

R groups can be linked to the cyclopentadienyl ring by any of the carbon atoms of the aromatic structure. R may occupy more than one carbon atom, meaning that there can be 1, 2, 3, 4 or 5 carbon of cyclopentadienyl ring substituted. In the context of the present invention, "heteroaromatic ligand" relates to all molecules that have in their constitution one or more aromatic rings in which at least one of the rings bears at least one heteroatom such as N, 0, S, Se, P, etc.

The present invention also relates to the procedure of obtaining the referred ruthenium or iron complexes of general formula (I) . In this context, three different procedures of obtaining the ruthenium or iron complexes are described below:

1. Replacement of one or two triphenylphosphanes in complex [M (CpR) ( PPh3 ) 2X] by one or two diphenylphosphane-benzene-3-sulfonate ligands or by one diphenylphosphane-benzene-3-sulfonate and the other one can be a different water soluble phosphane or any other type of phosphane, followed by reaction with a heteroaromatic ligand ( M= Ru, Fe; X= CI, I; CpR is a cyclopentadienyl derivative wherein R represents a biomolecule (for example aminoacid, peptide, oligopeptide, protein, protein fragment, stradiol, etc.) or a heteroatomatic ligand, or a bioactive organic compound or a radical -Rl, -R1-NH₂, -R1-C00H, -R1-C00-, - R1-0H, -RI-COONCH₃, where Rl is an alkyl or aryl group) .

2. Direct reaction of a ruthenium or iron salts (MX3) , with a cyclopentadienyl derivative (CpR) , diphenylphosphane-benzene-3-sulfonate and soluble phosphanes (equal or different) or mixture of diphenylphosphane-benzene-3-sulfonate and other phosphanes. Once purified, this precursor reacts with the heteroaromatic ligand. 3. Direct reaction of a ruthenium or iron salts (MX3) , with a cyclopentadienyl derivative (CpR) , one or two diphenylphosphane-benzene-3-sulfonate or diphenylphosphane-benzene-3-sulfonate and soluble phosphanes (equal or different) or mixture of diphenylphosphane-benzene-3-sulfonate and other phosphanes, and a heteroaromatic ligand.

Ruthenium or iron salts (MX3) , used in the context of the present invention comprise halides, nitrites, phosphates, perchlorates and carbonates of ruthenium.

The term "comprise" or "comprising", for the purpose if the present invention is intended to mean "including amongst other". It is not intended to mean "consisting only of".

All procedures are carried out in a reaction medium consisting of a solvent or a mixture of solvents selected from water, ethanol, methanol, ethyl acetate, isopropanol, terbutanol, ethylene glycol, diglime (Bis (2-methoxy ethyl ) ether) , chloroform, dichloromethane, benzene, toluene, acetone, tetrahydrofuran, dioxane acetonitrile . Reactions are preferentially carried out in methanol, water, ethanol and dichloromethane.

The previous procedures are carried out under temperature condition between -60°C and 300°C, and between 0.5 and 100 atmospheres of pressure, with or without stirring. The reactions are preferentially carried out in a temperature range of 5°C to 200 °C, and at normal pressures (latm) .

Another aspect of the invention relates to the procedures to obtain the ruthenium or iron complexes of formula I . In the procedures described below components and substituents have the same meaning as was given previously to describe the ruthenium or iron complexes of general formula (I) .

The first procedure (1.) comprises:

a) Replacement of one or two triphenylphosphanes in the complex [M(CpR) (PPh₃)₂X] by one or two diphenylphosphane-benzene-3-sulfonates or by one diphenylphosphane-benzene-3-sulfonate and other different water soluble phosphane or any other type of phosphane, M=Ru, Fe; X= CI, I; CpR is a cyclopentadienyl derivative wherein R represents a biomolecule (for example aminoacid, peptide, oligopeptide, protein, protein fragment, stradiol, etc.) or a heteroatomatic ligand, or a bioactive organic compound or a radical -Rl, -Rl-N¾, -Rl-COOH, -R1-COO-, - Rl-OH, -RI-COONCH3, where Rl is an alkyl or aryl group.

b) Reaction of the complex synthesized in a) after purified with a heteroaromatic ligand.

The complexes of formula (I) can be obtained from the second procedure (2.), which comprises:

a) Direct reaction of a ruthenium or iron salt (MX₃) , with a cyclopentadienyl derivative (CpR) , diphenylphosphane-benzene-3-sulfonate and soluble phosphanes (equal or different) or mixture of diphenylphosphane-benzene-3-sulfonate and other phosphanes .

b) Once purified, the complexes obtained in step a) react with a heteroaromatic ligand.

The third procedure (3.) consists in a direct reaction of a ruthenium or iron salt (MX₃) , with a cyclopentadienyl derivative (CpR) , one or two diphenylphosphane-benzene-3- sulfonate or diphenylphosphane-benzene-3-sulfonate and soluble phosphanes (equal or different) or mixture of diphenylphosphane-benzene-3-sulfonate and other phosphanes, and a heteroaromatic ligand.

Another aspect of the present invention relates to a composition with biological activity that comprises some ruthenium or iron complex of general formula (I) and any additional compound with biological activity.

The specific examples which are presented below serve to illustrate the nature of the present invention. These examples are included as illustrative examples only and should not be interpreted as limitations to the present invention .

Example 1 :

To a stirred solution of [RuCp (mTPPMs ) ₂C1 ] (0.47 g, 0.5 mmol) in methanol (25 mL) was added of AgCF3 S C>3 (0.13 g, 0.5 mmol) . The resulting yellow solution was stirred for one hour at room temperature followed by addition of 2,2'- bipyridine (0.09 g, 0.5 mmol) . The reaction mixture was heated to reflux for 4.5h with change of color from yellow to red. The precipitate of AgCl was removed by cannula- filtration and the solvent evaporated. The product was washed with Et₂<0 (2x10 mL) and vacuum dried.

Example 2 :

To a stirred solution of [RuCp (mTPPMs ) ₂C1 ] (0.47 g, 0.5 mmol) in methanol (25 mL) was added of AgCF3 S C>3 (0.13 g, 0.5 mmol) . The resulting yellow solution was stirred for one hour at room temperature followed by addition of 2- benzoylpyridine (0.09 g, 0.5 mmol) . The reaction mixture was heated to reflux for 2h with change of color from yellow to purple. The reaction mixture was cooled to room temperature, filtered and the solvent removed under reduced pressure; the product was washed with Et₂<0 (2xl0mL) and vacuum dried.

Example 3 :

To a stirred solution of [RuCp (mTPPMs ) ₂C1 ] (0.47 g, 0.5 mmol) in methanol (25 mL) was added of AgCF₃SC>3 (0.13 g, 0.5 mmol) . The resulting yellow solution was stirred for one hour at room temperature followed by addition of N- (4- methoxyphenyl ) imidazole (0.06 g, 0.5 mmol). The reaction mixture was stirred at room temperature for further 20 h, with change of color from yellow to orange. The precipitate of AgCl was removed by cannula-filtration and the solvent evaporated. The product was washed with Et₂<0 (2x10 mL) and vacuum dried.

Example 4 :

AgCF₃SC>3 (0.13 g, 0.5 mmol) was added to a solution of [RuCp (mTPPMs) ₂C1] (0.47 g, 0.5 mmol) in methanol (25 mL) .

The resultant yellow solution was stirred and after 1 h, 2- (2-pyridyl) benzo [b] thiphene (0.11 g, 0.5 mmol) was added.

After refluxing for 5 h the solution turned from yellow to brown. The reaction mixture was cooled to room temperature, filtered and the solvent removed under reduced pressure; the product was washed with Et₂<0 (2 x 10 mL) and vacuum dried .

Claims

Water-soluble organometallic ruthenium and/or iron compounds or their pharmaceutically acceptable salts or optically resolved enantiomers of general formula

(I)

wherein,

M is a ruthenium or iron atom; R represents a biomolecule (for example aminoacid, peptide, oligopeptide, protein, protein fragment, stradiol, etc.) or a heteroatomatic ligand, or a bioactive organic compound or a radical -Rl, -R1-NH2, -Rl- COOH, -R1-COO-, - Rl-OH, -R1-COONCH3, where Rl is nan alkyl or aryl group; LI and L2 comprise the following arangments :

- LI is a diphenylphosphane-benzene-3-sulfonate or any other monodentate water-soluble phosphane or any other phosphane ligand, and

- L2 is a monodentate heteroaromatic compound with a single or a multiring system in which one of the rings contains one heteroatom chosen from the group N, 0, S, Se or P;

or

- LI and L2 represent a bidentate heteroaromatic compound composed by a single or a multiring system in which one or two of the rings contain one heteroatom chosen from the group N, 0, S, Se or P.

Process for the preparation of water-soluble organometallic ruthenium and/or iron compounds or their pharmaceutically acceptable salts or optically resolved enantiomers described in claim 1, comprising :

i) Replacement of one or two triphenylphosphanes in the complex [M(CpR) (PPh3)2 ] by one or two diphenylphosphane-benzene-3-sulfonates or by one diphenylphosphane-benzene-3-sulfonate and other different water soluble phosphane or any other type of phosphane, (M=Ru, Fe; X=C1, I; CpR is a cyclopentadienyl derivative wherein R represents a biomolecule (for example aminoacid, peptide, oligopeptide, protein, protein fragment, stradiol, etc.) or a heteroatomatic ligand, or a bioactive organic compound or a radical -Rl, -R1-NH2, -R1-C00H, - R1-C00-, - R1-0H, -R1-C00NCH3, where Rl is an alkyl or aryl group) , and;

ii) reaction of compound of step i) with a heteroaromatic ligand.

Process for the preparation of water-soluble organometallic ruthenium and iron compounds or their pharmaceutically acceptable salts or optically resolved enantiomers according to claim 2, wherein the reaction temperature is from -60°C to 300°C and the pressure is from 0,5 atm to 100 atm.

4. Process for the preparation of water-soluble organometallic ruthenium and/or iron compounds or their pharmaceutically acceptable salts or optically resolved enantiomers described in claim 1, comprising :

i) direct reaction of a ruthenium or iron salts of general formula MX3, wherein X is halide, nitrite, phosphate, perchlorate or carbonate, with a cyclopentadienyl derivative, diphenylphosphane-benzene-3-sulfonate and soluble phosphanes (equal or different) or mixture of diphenylphosphane-benzene-3- sulfonate and other phosphanes, and

ii) reaction of compound obtained in step i) with a heteroaromatic ligand.

5. Process for the preparation of water-soluble organometallic ruthenium and/or iron compounds or their pharmaceutically acceptable salts or optically resolved enantiomers according to claim 4, wherein the reaction temperature is from -60°C to 300°C and the pressure is from 0,5 atm to 100 atm.

6. Process for the preparation of water-soluble organometallic ruthenium and/or iron compounds or their pharmaceutically acceptable salts or optically resolved enantiomers described in claim 1, comprising direct reaction of a ruthenium and/or iron salts of general formula MX₃, wherein X is halide, nitrite, phosphate, perchlorate or carbonate, with a cyclopentadienyl derivative, one or two diphenylphosphane-benzene-3-sulfonate or diphenylphosphane-benzene-3-sulfonate and soluble phosphanes (equal or different) or mixture of diphenylphosphane-benzene-3-sulfonate and other phosphanes, and a heteroaromatic ligand.

Process for the preparation of water-soluble organometallic ruthenium and/or iron compounds or their pharmaceutically acceptable salts or optically resolved enantiomers according to claim 6, wherein the reaction temperature is from -60°C to 300°C and the pressure is from 0,5 atm to 100 atm.

Water-soluble organometallic ruthenium and/or iron compound or their pharmaceutically acceptable salts or optically resolved enantiomers described in claim 1, for the treatment and/or prevention of tumors and/or tumor metastasis.