N-ACYLHYDRAZONIC COMPOUNDS, USE IN THE TREATMENT OF AMYLOID AND NON-AMYLOID DEGENERATIVE AGGREGOPATHIES, AND PHARMACEUTICAL COMPOSITION

Abstract

The present invention relates to a family of N-acylhydrazonic compounds structurally derived from 1-methyl-1H-imidazole-2-carboxaldehyde, or pharmaceutically acceptable salts thereof, and the use of said compounds to prevent and/or treat amyloid (such as Alzheimer's, Parkinson's and type 2 diabetes) and non-amyloid (such as cataracts) degenerative aggregopathies These compounds act as attenuators of the metal-protein interaction, preventing and/or decreasing protein oligomerization through competition with the target peptide or protein for the binding of physiological metal ions and, possibly, by modulating the protein-protein interaction itself. The invention also details four compounds specifically described as examples of N-acylhydrazones derived from 1-methyl-1H-imidazole-2-carboxaldehyde, namely: 1-methyl-1H-imidazole carboxaldehyde isonicotinoyl hydrazone, 1-methyl-1H-imidazole-2-carboxaldehyde benzoyl hydrazone, 1-methyl-1H-imidazole-2-carboxaldehyde 2-furoyl hydrazone and 1-methyl-1H-imidazole-2-carboxaldehyde 2-thiophenyl hydrazone. The current application also comprises pharmaceutical compositions.

Claims

1. An N-acylhydrazonic compound, structurally derived from 1-methyl-1H-imidazole-2-carboxaldehyde, or a pharmaceutically acceptable salt thereof, having the following formula (I): ##STR00004## in which Ar is a 5- or 6-membered aromatic or heteroaromatic ring.

2. The N-acylhydrazonic compound according to claim 1, having the following formulae (II) or (III): ##STR00005## in which: A represents CR.sup.4 or N; D represents CR.sup.4 or N; E represents CR.sup.4 or N; X represents O, S or NH; Z represents CR.sup.4 or N; R.sup.1 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group; R.sup.2 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group; R.sup.3 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group; and R.sup.4 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group, or a pharmaceutically acceptable salt thereof.

3. The N-acylhydrazonic compound according to claim 2, wherein A, D and E present a number of nitrogen heteroatoms not superior to two, or a pharmaceutically acceptable salt thereof.

4. The N-acylhydrazonic compound according to claim 2, wherein A=D=CR.sup.4, E=N and R.sup.1=R.sup.2=R.sup.4=H, which structure is represented by the formula (IV): ##STR00006## or a pharmaceutically acceptable salt thereof.

5. The N-acylhydrazonic compound according to claim 2, wherein A=D=E=CR.sup.4 and R.sup.1=R.sup.2=R.sup.4=H, which structure is represented by the formula (V): ##STR00007## or a pharmaceutically acceptable salt thereof.

6. The N-acylhydrazonic compound according to claim 2, wherein X=O, Z=CR.sup.4 and R.sup.3=R.sup.4=H, which structure is represented by the formula (VI): ##STR00008## or a pharmaceutically acceptable salt thereof.

7. The N-acylhydrazonic compound according to claim 2, wherein X=S, Z=CR.sup.4 and R.sup.3=R.sup.4=H, which structure is represented by the formula (VII): ##STR00009## or a pharmaceutically acceptable salt thereof.

8. A method for treating amyloid or non-amyloid degenerative aggregopathy, comprising: administering, to a subject in need thereof, the N-acylhydrazonic compound of formula (I) as defined in claim 1, or a pharmaceutically acceptable salt thereof, as an active component.

9. The method according to claim 8, wherein the amyloid or non-amyloid degenerative aggregopathy is Alzheimer's, Parkinson's, type 2 diabetes, or cataracts.

10. The method according to claim 8, wherein said N-acylhydrazonic compound is a compound represented by the following formulae (II) or (III): ##STR00010## in which: A represents CR.sup.4 or N; D represents CR.sup.4 or N; E represents CR.sup.4 or N; X represents O, S or NH; Z represents CR.sup.4 or N; R.sup.1 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group; R.sup.2 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group; R.sup.3 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group; and R.sup.4 a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group, or a pharmaceutically acceptable salt thereof.

11. The method according to claim 10, wherein said compounds of formulas (II) or (III) are selected between those represented by the formulae (IV), (V), (VI) or (VII): ##STR00011## or pharmaceutically acceptable salts thereof.

12. A pharmaceutical composition, comprising: a compound of formula (I) as defined in claim 1, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically suitable excipient.

13. The pharmaceutical composition according to claim 12, wherein the compound of formula (I) has the following formulae (II) or (III): ##STR00012## in which: A represents CR.sup.4 or N; D represents CR.sup.4 or N; E represents CR.sup.4 or N; X represents O, S or NH; Z represents CR.sup.4 or N; R.sup.1 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group; R.sup.2 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group; R.sup.3 represents a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group; and R.sup.4 a hydrogen, a halogen, an alkyl group, an alkoxyl group, an ester group, an acyl group, a phenoxyl group, a cyano group, a nitro group, a hydroxyl group, or a thioalkoxyl group, or a pharmaceutically acceptable salt thereof.

14. The pharmaceutical composition according to claim 13, wherein the compounds of formulae (II) or (III) are one of the compounds of formulae (IV), (V), (VI) or (VII: ##STR00013## or pharmaceutically acceptable salts thereof.

15. A method for treating amyloid or non-amyloid degenerative aggregopathy, comprising: administering, to a subject in need thereof, the N-acylhydrazonic compound of claim 2, or a pharmaceutically acceptable salt thereof, as an active component.

16. A method for treating amyloid or non-amyloid degenerative aggregopathy, comprising: administering, to a subject in need thereof, the N-acylhydrazonic compound of claim 3, or a pharmaceutically acceptable salt thereof, as an active component.

17. A method for treating amyloid or non-amyloid degenerative aggregopathy, comprising: administering, to a subject in need thereof, the N-acylhydrazonic compound of claim 4, or a pharmaceutically acceptable salt thereof, as an active component.

18. A method for treating amyloid or non-amyloid degenerative aggregopathy, comprising: administering, to a subject in need thereof, the N-acylhydrazonic compound of claim 5, or a pharmaceutically acceptable salt thereof, as an active component.

19. A method for treating amyloid or non-amyloid degenerative aggregopathy, comprising: administering, to a subject in need thereof, the N-acylhydrazonic compound of claim 6, or a pharmaceutically acceptable salt thereof, as an active component.

20. A method for treating amyloid or non-amyloid degenerative aggregopathy, comprising: administering, to a subject in need thereof, the N-acylhydrazonic compound of claim 7, or a pharmaceutically acceptable salt thereof, as an active component.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0053] The present invention will be described in more detail below, with reference to the attached figures which, in a schematic way and not limiting the inventive scope, represent examples of embodiment thereof. The illustrations are as follows:

[0054] FIG. 1 displays the ORTEP (Oak Ridge Thermal Ellipsoid Plot) representation of compounds of formulae a) (IV), b) (V), c) (VI), and d) (VII). The ellipsoids were drawn at the 50% probability level.

[0055] FIG. 2 shows the hydrogen bond interactions in compounds of formulae a) (IV), b) (V), c) (VI), and d) (VII).

[0056] FIG. 3 presents the π-π stacking interactions in compounds of formulae a) (V), b) (VI), e c) (VII).

[0057] FIG. 4 shows the .sup.1H NMR spectrum (400 MHz) of the compound of formula (IV) in DMSO-d.sub.6, at room temperature;

[0058] FIG. 5 shows the .sup.1H NMR spectrum (400 MHz) of the compound of formula (V) in DMSO-d.sub.6, at room temperature;

[0059] FIG. 6 shows the .sup.1H NMR spectrum (400 MHz) of the compound of formula (VI) in DMSO-d.sub.6, at room temperature;

[0060] FIG. 7 shows the .sup.1H NMR spectrum (400 MHz) of the compound of formula (VII) in DMSO-d.sub.6, at room temperature;

[0061] FIG. 8 displays the absorption spectra of INHHQ in a solution containing 1% DMSO/water (5×10.sup.−5 mol L.sup.−1) at 17° C., over 4 days;

[0062] FIG. 9 shows the absorption spectra of the compounds of formulae a) (IV) and b) (VII) in a solution containing 1% DMSO/water (5×10.sup.−5 mol L.sup.−1) at 17° C., over 4 days;

[0063] FIG. 10a presents ultraviolet/visible absorption spectra of mixtures of different molar fractions of the compound of formula (IV) and copper(II);

[0064] FIG. 10b displays a Job plot for this system at 374 nm;

[0065] FIG. 11 presents the cytotoxicity of the N-acylhydrazones of formulae (IV), (V), (VI) and (VII) in H4 human neuroglioma cells;

[0066] FIG. 12a shows the effect of the compound of formula (IV) on the cellular model of SynT-Sph1 aggregation in H4 cells by quantifying inclusions in transfected cells from images obtained by fluorescence microscopy;

[0067] FIG. 12b shows the effect of the compound of formula (IV) on the cellular model of SynT-Sph1 aggregation in H4 cells through representative images of the inclusions observed by fluorescence microscopy.

DETAILED DESCRIPTION OF THE INVENTION

[0068] Unless defined otherwise, the technical and scientific terms used in connection with the present invention must have the meanings that are commonly understood by those skilled in the technique. The meaning and scope of the terms must certainly be intelligible; however, in the case of any latent ambiguity, the definitions provided herein take precedence over any extrinsic or dictionary definitions.

[0069] In this context, the present invention relates to a series of compounds belonging to the class of N-acylhydrazones and structurally derived from 1-methyl-1H-imidazole-2-carboxaldehyde, or even pharmaceutically acceptable salts thereof, with the general formula (I), as referenced below:

##STR00001##

[0070] in which the Ar radical is a 5- or 6-membered aromatic or heteroaromatic ring. The structure represented by formula (I) can be broken down into formulae (II) and (III):

##STR00002##

[0071] in which:

[0072] A represents the radicals CR.sup.4 or N;

[0073] D represents the radicals CR.sup.4 or N;

[0074] E represents the radicals CR.sup.4 or N;

[0075] X represents the radicals O, S or NH;

[0076] Z represents the radicals CR.sup.4 or N;

[0077] R.sup.1 represents the radicals hydrogen (—H), halo (—F, —CI, —Br, —I), alkyl (—CH.sub.3, —CH.sub.2CH.sub.3, etc.), alkoxyl (—OCH.sub.3, —OCH.sub.2CH.sub.3, etc.), ester [—C(═O)—OCH.sub.3, etc.], acyl [—C(═O)—CH.sub.3, etc.], phenoxyl (—OPh), cyano (—CN), nitro (—NO.sub.2), hydroxyl (—OH) or thioalkoxyl (—SCH.sub.3, —SCH.sub.2CH.sub.3, etc.);

[0078] R.sup.2 represents the radicals hydrogen (—H), halo (—F, —CI, —Br, —I), alkyl (—CH.sub.3, —CH.sub.2CH.sub.3, etc.), alkoxyl (—OCH.sub.3, —OCH.sub.2CH.sub.3, etc.), ester [—C(═O)—OCH.sub.3, etc.], acyl [—C(═O)—CH.sub.3, etc.], phenoxyl (—OPh), cyano (—CN), nitro (—NO.sub.2), hydroxyl (—OH) or thioalkoxyl (—SCH.sub.3, —SCH.sub.2CH.sub.3, etc.);

[0079] R.sup.3 represents the radicals hydrogen (—H), halo (—F, —CI, —Br, —I), alkyl (—CH.sub.3, —CH.sub.2CH.sub.3, etc.), alkoxyl (—OCH.sub.3, —OCH.sub.2CH.sub.3, etc.), ester [—C(═O)—OCH.sub.3, etc.], acyl [—C(═O)—CH.sub.3, etc.], phenoxyl (—OPh), cyano (—CN), nitro (—NO.sub.2), hydroxyl (—OH) or thioalkoxyl (—SCH.sub.3, —SCH.sub.2CH.sub.3, etc.);

[0080] e R.sup.4 represents the radicals hydrogen (—H), halo (—F, —CI, —Br, —I), alkyl (—CH.sub.3, —CH.sub.2CH.sub.3, etc.), alkoxyl (—OCH.sub.3, —OCH.sub.2CH.sub.3, etc.), ester [—C(═O)—OCH.sub.3, etc.], acyl [—C(═O)—CH.sub.3, etc.], phenoxyl (—OPh), cyano (—CN), nitro (—NO.sub.2), hydroxyl (—OH) or thioalkoxyl (—SCH.sub.3, —SCH.sub.2CH.sub.3, etc.).

[0081] It is important to note that the compounds described above through the formula (II) can present, in the positions represented by the letters A, D and E, a carbon atom bound to any of the groups defined by R.sup.4 and/or the heteroatom nitrogen. Note that the maximum number of nitrogen atoms in the 6-membered ring is two.

[0082] It should also be noted that, for the compounds previously described by the formula (III), the position represented by the letter X can be occupied by an oxygen atom, a sulfur atom or by the NH group, and the position represented by the letter Z, by a carbon atom bound to any group defined by R.sup.4 or the heteroatom nitrogen.

[0083] In a second modality, this invention specifically comprises the compounds of structural formulae (IV), (V), (VI) and (VII):

##STR00003##

[0084] In this regard, it should be noted that compounds (IV) and (V) are derived from formula (II), by the substitutions A=D=CR.sup.4, E=N e R.sup.1=R.sup.2=R.sup.4=H (1-methyl-1H-imidazole-2-carboxaldehyde isonicotinoyl hydrazone) and A=D=E=CR.sup.4 e R.sup.1=R.sup.2=R.sup.4=H (1-methyl-1H-imidazole-2-carboxaldehyde benzoyl hydrazone), respectively.

[0085] It should also be noted that compounds (VI) and (VII) are derived from formula (III), through the substitutions X=O, Z=CR.sup.4 e R.sup.3=R.sup.4=H (1-methyl-1H-imidazole carboxaldehyde 2-furoyl hydrazone) and X=S, Z=CR.sup.4 e R.sup.3=R.sup.4=H (1-methyl-1H-imidazole-2-carboxaldehyde 2-thiophenyl hydrazone), respectively.

[0086] Still regarding the above examples, it should be noted that all the specific examples of formulae (II) and (III), namely compounds (IV), (V), (VI) and (VII) are N-acylhydrazones structurally derived from 1-methyl-1H-imidazole-2-carboxaldehyde.

[0087] For the purpose of detailing the aforementioned cases, some experimental data referring to N-acylhydrazones (IV), (V), (VI) and (VII) can be found below.

[0088] Synthesis: one universal way of synthesizing the N-acylhydrazones is through condensation reactions, which constitute a general class already well described in the literature, between 1-methyl-1H-imidazole-2-carboxaldehyde and different hydrazides. The aldehyde is weighed into a round bottom reaction flask and solubilized in ethanol. The hydrazide is weighed in order to attain a 1:1 molar ratio and solubilized in the same solvent, in a beaker. The hydrazide's solution is then dropwise added to the aldehyde, under constant stirring and mild heating. Drops of HCl are added to catalyze the reaction, and the mixture is kept under reflux for a few hours. The system is then cooled and warehoused at room temperature for slow evaporation of the solvent and precipitate formation. This, in turn, is filtered, washed with cold solvent and dried at room temperature. Single crystals can be isolated from the mother liquor, allowing for structural analysis through X-ray diffraction.

[0089] Melting points: The melting points of the compounds of formulae (IV), (V), (VI) and (VII) were determined in triplicate and used as a criterion of purity.

[0090] The determined values were: [0091] (IV): 223±3° C. [0092] (V): 128±1° C. [0093] (VI): 153±2° C. [0094] (VII): 215±2° C.

[0095] X-ray Crystallography: Table 1 presents some data on the crystals employed and others related to the collection and refinement of the structures. Selected bond distances and angles can be seen in Table 2. Table 3 summarizes geometric parameters of the H-bond interactions observed in crystal networks. On the other hand, the π-π stacking interactions are summarized in Table 4.

TABLE-US-00001 TABLE 1 Crystallographic data for compounds of formulae (IV), (V), (VI) and (VII). Compound (IV) (V) (VI) (VII) Formula C.sub.11H.sub.12N.sub.5OCl C.sub.12H.sub.19N.sub.4O.sub.4Cl C.sub.10H.sub.13N.sub.4O.sub.3Cl C.sub.10H.sub.13N.sub.4O.sub.2SCl Formula weight 265.71 318.76 272.69 288.75 (g mol.sup.−1) Crystal system Monoclinic Monoclinic Monoclinic Monoclinic Space group P2.sub.1 P2.sub.1/c P2.sub.1/c P2.sub.1/n a (Å) 4.3066 (4) 9.4095 (6) 8.4271 (2) 7.0656 (4) b (Å) 17.7428 (11) 23.9779 (10) 18.8539 (5) 18.0958 (6) c (Å) 8.1657 (5) 7.4947 (5) 8.2549 (2) 10.6824 (4) α = γ (°) 90.00 90.00 90.00 90.00 β (°) 102.475 (7) 110.961 (8) 102.381 (3) 101.665 (4) V (Å.sup.3) 609.22 (8) 1579.05 (18) 1281.07 (2) 1337.67 (10) Z 2 4 4 4 Temperature (K) 293 (2) 293 (2) 293 (2) 293 (2) Crystal size (mm) 0.12 × 0.26 × 0.54 0.42 × 0.52 × 1.00 0.34 × 0.60 × 1.08 0.26 × 0.52 × 1.01 μ(Mo Kα) (mm.sup.−1) 0.309 0.263 0.305 0.442 Refl. 7384/3951  20662/4022  33691/3451  2331/3383  measured/independent R.sub.int 0.0389 0.0322 0.0301 0.0363 Parameters 163 191 164 164 R.sub.obs [F.sub.o > 2σ(F.sub.o)] 0.0493 0.0436 0.0385 0.0344 R.sub.all 0.815 0.0668 0.0494 0.0480 wR.sub.obs [F.sub.o.sup.2 > 2σ(F.sub.o).sup.2] 0.0919 0.1043 0.0985 0.0854 wR.sub.all 0.1077 0.1185 0.1036 0.0936 S 1.047 1.020 1.072 1.052 Δρ.sub.max, Δρ.sub.min (e Å.sup.−3) 0.262/−0.239 0.310/−0.226 0.263/−0.215 0.260/−0.215

TABLE-US-00002 TABLE 2 Selected geometric parameters for compounds (IV), (V), (VI) and (VII). (IV) (V) (VI) (VII) Bond distance (Å) C3—C4 1.449(4) 1.447(2) 1.445(2) 1.442(2) C4—N3 1.272(4) 1.272(2) 1.277(2) 1.275(2) N3—N4 1.272(4) 1.356(2) 1.277(2) 1.356(2) N4—C5 1.364(4) 1.365(2) 1.364(2) 1.367(2) C5—O1 1.217(4) 1.223(2) 1.220(2) 1.221(2) C5—C6 1.504(4) 1.489(2) 1.464(2) 1.466(2) Bond angle (°) C3—C4—N3 120.0(3) 115.6(1) 116.6(1) 116.3(1) C4—N3—N4 115.3(2) 118.2(1) 117.1(1) 117.3(1) N3—N4—C5 117.5(2) 117.6(1) 117.1(1) 117.0(1) N4—C5—C6 115.3(2) 116.4(1) 113.8(1) 115.4(1) N4—C5—O1 123.1(3) 121.5(1) 123.0(2) 122.5(1) C6—C5—O1 121.6(3) 122.5(1) 123.2(1) 122.2(1) Torsion angle (°) C3—C4—N3—N4 179.7(3) −178.9(1) 179.0(1) 178.0(1) C4—N3—N4—C5 177.1(3) 176.7(1) −179.1(1) −178.5(1) N3—N4—C5—C6 174.8(3) −178.9(1) −179.1(1) 177.9(2) N3—N4—C5—O1 −4.7(5) 1.2(2) 2.9(2) −2.6(2) C7—C6—C5—O1 171.8(4) −14.2(2) 177.4(2) 172.3(2)

TABLE-US-00003 TABLE 3 Hydrogen bond geometric parameters for compounds (IV), (V), (VI) and (VII). D-H . . . A D-H (Å) H . . . A (Å) D . . . A (Å) D-H . . . A (°) (IV) N2—H2n . . . N5.sup.i 1.02 1.74 2.754(4) 171.0 N4—H4n . . . Cl 0.97 2.18 3.126(3) 165.0 Symmetry code: .sup.i(1 − x, ½ + y, −z) (V) N2—H2n . . . O2 0.86 1.87 2.727(2) 173.0 N4—H4n . . . O3 0.80 2.05 2.818(2) 159.0 O2—H2a . . . Cl.sup.i 0.91 2.22 3.130(2) 174.0 O2—H2b . . . O1 0.83 2.15 2.959(2) 163.0 O2—H2b . . . N3 0.83 2.47 2.975(2) 120.0 O3—H3a . . . O4 0.88 1.91 2.786(2) 174.0 O3—H3b . . . Cl.sup.ii 0.85 2.30 3.141(2) 170.0 O4—H4a . . . Cl.sup.iii 0.79 2.44 3.223(2) 174.0 O4—H4b . . . Cl.sup.iv 0.84 2.34 3.178(2) 174.0 Symmetry code: .sup.i(1 + x, y, z); .sup.ii(−x, −y, −z); .sup.iii(−x, ½ + y, ½ − z); .sup.iv(−x, −y, 1 − z) (VI) N2—H2n . . . O3 0.86 1.93 2.775(2) 169.0 N4—H4n . . . Cl 0.89 2.29 3.155(1) 163.0 O3—H3a . . . N3 0.82 2.43 3.025(2) 130.0 O3—H3a . . . O1 0.82 2.29 3.074(2) 161.0 O3—H3b . . . Cl.sup.i 0.87 2.23 3.097(1) 177.0 Symmetry code: .sup.i(1 − x, 1 − y, 1 − z) (VII) N2—H2n . . . O2 0.86 1.91 2.759(2) 172.0 N4—H4n . . . Cl 0.85 2.37 3.193(1) 166.0 O2—H2a . . . N3 0.76 2.44 2.985(2) 130.0 O2—H2a . . . O1 0.76 2.30 3.021(2) 160.0 O2—H2b . . . Cl.sup.i 0.86 2.34 3.216(1) 172.0 Symmetry code: .sup.i(1 − x, −y, 1 −z)

TABLE-US-00004 TABLE 4 Geometric π-π stacking parameters in compounds (V), (VI) and (VII). Centroid-centroid Centroid-plane Horizontal Compound distance (Å) distance (Å) displacement (Å) (V) 3.532 3.449 0.76 (VI) 3.635 3.304 1.52 (VII) 3.632 3.392 1.30

[0096] Elemental analysis: The elemental analysis of carbon, hydrogen and nitrogen for compounds (IV), (V), (VI) and (VII) is detailed in Table 5, in which the calculated values for each formula and the experimental values obtained are presented.

TABLE-US-00005 TABLE 5 Elemental analysis of the described N-acylhydrazones. C C H H N N Calc Exp Calc Exp Calc Exp (IV) 49.72% 50.8% 4.55% 4.8% 26.37% 27.4% C.sub.11H.sub.12N.sub.5OCl (V) 45.22% 45.4% 6.00% 6.0% 17.58% 18.1% C.sub.12H.sub.19N.sub.4O.sub.4Cl (VI) 44.05% 43.7% 4.80% 4.8% 20.55% 20.5% C.sub.10H.sub.13N.sub.4O.sub.3Cl (VII) 41.60% 41.4% 4.53% 4.5% 19.41% 19.3% C.sub.10H.sub.13N.sub.4O.sub.2SCl * Theoretical values calculated using the state of protonation, counter-ions and crystallization solvents observed in the respective structures.

[0097] .sup.1H Nuclear Magnetic Resonance: Most hydrazones present, in their NMR spectra, different species in DMSO-d.sub.6 solution. In theory, there are four possible configurations: a combination of the iminol and amido tautomers, and the geometric (E) and (Z) isomers. In practice, (Z) isomers are usually absent or present in very small amounts, due to their lower conformational stability.

[0098] Table 6 summarizes the assignments for the major set of signals present in the spectra of the synthesized hydrazones, according to the numbering scheme presented in FIGS. 4 to 7, which also present the respective one-dimensional .sup.1H spectra.

TABLE-US-00006 TABLE 6 Assignments for the major sets of .sup.1H NMR signals of the N-acylhydrazones. H/δ (ppm) (IV) (V) (VI) (VII) 1 3.97 (s, 3H) 4.01 (s, 3H) 3.99 (s, 3H) 4.01 (s, 3H) 2 — — — — 3 — — — — 4 7.36 (s, 1H) 7.81 (s, 1H) 7.82 (d, 1H) 7.83 (d, 1H) 5 7.07 (d, 1H) 7.72 (d, 1H) 7.73 (d, 1H) 7.73 (d, 1H) 6 8.42 (s, 1H) 8.80 (s, 1H) 8.76 (s, 1H) 8.87 (s, 1H) 7 — — — — 8 12.07 (s, 1H) 12.90 (s, 1H) 12.96 (s, 1H) 13.21 (s, 1H) 9 — — — — 10 — — — — 11 7.81 (dd, 2H)* 8.02 (d, 2H)* 7.59 (d, 1H) 7.97 (dd, 1H) 12 8.79 (dd, 2H)** 7.56 (t, 2H)** 6.75 (dd, 1H) 7.27 (dd, 1H) 13 — 7.65 (t, 1H) 8.02 (dd, 1H) 8.25 (d, 1H) 14 ** ** — — 15 * * — —

[0099] Computational calculation of pharmacologic parameters: In silico (theoretic) pharmacological analyzes allow to determine some characteristics of the compounds that are relevant in the development of a new drug. Lipinski's Rule of Five is used as a reference. Lipinski states that a good candidate for drug development has a limit of multiples of 5 as values for some parameters: log P less than or equal to 5, molecular weight (MW) less than or equal to 500, hydrogen bond acceptors (HBA) less than or equal to 10 and hydrogen bond donors (HBD) less than or equal to 5. The compound in question may have only one violation of these parameters to be considered a promising drug candidate. The rules allow, therefore, for a good theoretical prediction of the oral bioavailability profile and permeability of new substances.

[0100] The first analyzed parameter is the molecular weight (MW), related to the ease with which a drug can permeate the cell membrane. The lower the molecular weight, the more easily the molecule crosses membranes and can even pass through cellular pores or intracellular space. The second and third analyzed parameters are log P and log S. Log P, the partition coefficient, represents the hydrophilic-lipophilic balance of the molecule, while log S refers to the solubility of the compound in aqueous solution.

[0101] Such parameters combined are extremely important in the context of cellular permeability, since it is necessary that the drug does not have a very high lipophilicity, which would cause its retention in the highly lipophilic cellular space, nor a very high hydrophilicity, which would result in great difficulty to cross the lipid membranes.

[0102] The HBA and HBD parameters (Hydrogen Bond Acceptors and Hydrogen Bond Donors, respectively) are important because they assess the amount of hydrogen acceptors or donors in the molecule, aiming at the interaction with biological targets such as, for example, amyloidogenic proteins. Since hydrogen interactions play a fundamental role in the binding between proteins and small molecules, it is crucial for a drug to present an ideal balance between donors and receptors of these interactions when considering affinity for the molecular target.

[0103] PSA, in turn, is the polar surface area, which evaluates the degree of polarity of the molecule, that is, the greater the concentration of partial charges in some region of the molecule, the greater its hydrophilic character, which, in principle, would increase the solubility. However, it would hinder the ability of lipid penetration.

[0104] Another parameter that can be taken into account when evaluating a potential drug is called Druglikeness. This is a value determined by comparing fragments of the compounds with a database of commercially available compounds and with a database of non-drug compounds. The molecule in question is compared with 3,300 commercial drugs and 15,000 chemical substances.

[0105] Calculations were performed using the Osiris Property Explorer: DataWarior™ software. The new hydrazones are considerably more soluble (at least ten times) than INHHQ. The values calculated for their solubilities are shown in Table 7, together with the pharmacological parameters described above. All the new hydrazones have a partition coefficient (log P) within the ideal range to cross biological barriers, such as the blood-brain barrier, a characteristic that is crucial for the development of drugs that act at the brain. The greater solubility of the new ligands was verified experimentally.

TABLE-US-00007 TABLE 7 In silico pharmacological descriptors of N-acylhydrazones (IV), (V), (VI) and VII), and comparison with those calculated for INHHQ. Hidrazone INHHQ (IV) (V) (VI) (VII) MW 292.30 229.24 228.25 218.22 234.28 c log P 2.2250 0.3832 1.3841 0.5728 1.2507 c log S −3.360 −0.688 −1.483 −1.165 −1.493 HBA 6 6 5 6 5 HBD 2 1 1 1 1 PSA 87.47 72.17 59.28 72.42 87.52 Druglikeness 4.42 5.85 5.85 5.77 7.43

[0106] Experimental octanol-water partition coefficient (log P): The experimental values of log P were determined for only some of the hydrazones in order to prove the accuracy of the computational calculations. Tris buffer 10.sup.−2 mol L.sup.−1 pH 7.4 was used as the aqueous phase. Both phases were prepared separately, and contained the hydrazone of interest at low concentrations (5×10.sup.−5 mol L.sup.−1). An ultraviolet/visible molecular absorption spectrum was acquired for each of the phases before mixing. The mixture was stirred at 37° C., protected from light. At the end of the incubation, the mixture was centrifuged for 10 minutes at 3000 rpm, and the layers were separated using pipettes. The concentrations in each phase were measured at the wavelength of greatest absorption of each hydrazone in the respective solvent, through calibration curves. Each compound was analyzed in triplicate and P was calculated as the average concentration ratio C.sub.o/C.sub.a where C.sub.o is the concentration in the organic phase and C.sub.a in the aqueous phase.

[0107] Table 8 shows the experimental log P values obtained for the N-acylhydrazones of formulas (IV) and (V), and the calculated values, taken from Table 7, for comparison purposes. Experimental results were obtained using buffer with physiological pH, and the mixing and separation steps were performed at average human body temperature. This gives the experiment greater biological relevance compared to computational calculations. Even so, the values determined are in agreement with those calculated.

TABLE-US-00008 TABLE 8 Experimental and calculated log P values for compounds (IV) and (V). Hidrazone Experimental Calculated (IV) 0.67 ± 0.03 0.38 (V) 1.49 ± 0.13 1.38

[0108] Stability in aqueous solution containing 1% DMSO: Compounds were prepared at low concentrations (5×10.sup.−5 mol L.sup.−1) in a solution containing 1% DMSO in ultra-pure water. Absorption spectra were obtained between 200 and 800 nm in a molecular absorption spectrophotometer at regular intervals over 12 hours. A final measurement was performed after four days. The room temperature was maintained at 17° C. throughout the experiment.

[0109] Under these conditions, and according to FIG. 8, INHHQ presents a decrease of approximately 12% in the intensity of its hydrazonic band at 292 nm over 4 days.

[0110] On the other hand, the new hydrazones derived from 1-methyl-1H-imidazole-2-carboxaldehyde are much more stable. The most stable compound, described by formula (IV), shows a decrease of less than 2% in the intensity of the absorption signal of the hydrazonic band, being extremely stable under these conditions. Representative hydrazone absorption spectra are shown in FIG. 9.

[0111] Affinity constant for copper(II): The affinity constant of compound (IV) for copper(II) was determined using the Method of Continuous Variations, which consists of preparing mixtures of different molar fractions of ligand and metal, followed by measuring their UV-Vis absorbance. From these data, it is possible to calculate the stoichiometry of the complex generated, as well as its formation constant. FIG. 10a shows the spectra of the different metal-to-ligand ratios and the wavelengths of maximum absorption of the pure ligand (317 nm) and the complex (374 nm).

[0112] The presence of an isosbestic point indicates that there are only two absorbing species in equilibrium: the complex, formed in mixtures up to 0.5 molar fraction, and the excess of ligand that occurs in mixtures with higher molar fractions. This indicates that the ML-type complex (i.e., 1:1 stoichiometry) is formed preferentially under the conditions employed, which can be confirmed by the Job plot in FIG. 10b, which shows the maximum absorption at 374 nm occurring at the 0.5 molar fraction.

[0113] From this information it is possible to calculate the complex formation constant which, for the compound of formula (IV), has a value of 5.66±0.08 at 25° C. This value is approximately one thousand times lower than that presented by clioquinol under similar conditions, which indicates that the interaction with metal ions is more moderate for the N-acylhydrazone with formula (IV), as expected for an effective MPAC.

[0114] Studies in H4 cells: The four exemplified compounds were tested in a human neuroglioma cell line (H4 cells) for their toxicity, through the MTT assay, which measures the metabolic activity of the cells by a reductive and colorimetric reaction of the reagent. FIG. 11 presents the results obtained in the form of percentage of cell survival. None of the 1-methyl-1H-imidazole-2-carboxaldehyde-derived hydrazones evaluated showed significant toxicity to these cells compared to the vehicle (culture medium containing 1% DMSO), all of which were less toxic than INHHQ.

[0115] The isoniazid-derived hydrazone of formula (IV) was evaluated in greater detail in a cellular model of α-synuclein aggregation in H4 cells. This model consists of the co-transfection of an α-synuclein construct containing the first 83 amino acids of the EGFP protein linked to its C-terminal portion (SynT) with the synphilin-1 protein (Sph1), resulting in positive inclusions for α-Syn which can be observed by fluorescence microscopy after immunostaining. This compound showed a significant effect on the amount of cells without inclusions and with more than 10 inclusions (FIG. 12a) and also on the sizes of inclusions observed (FIG. 12b). It was also found that the compound does not change the levels of α-Syn expression, and that its effect is directly related to the quaternary structure of the aggregates, having a direct impact on their morphology, which are less compact after treatment.

[0116] With respect to its application, the present invention refers, at first, to the use of the family of compounds defined above by formulas (II) and (III) as attenuators of anomalous metal-protein interactions, since they are chelators with moderate affinity for certain physiological metal ions. Such compounds act in the inhibition of defective folding and protein aggregation, preventing and treating degenerative aggregopathies, such as Alzheimer's and Parkinson's diseases, type 2 diabetes and cataracts.

[0117] The term “treatment” as used herein, unless otherwise indicated, includes the treatment of Alzheimer's disease, Parkinson's disease, type 2 diabetes and cataracts, which comprises administering a therapeutically effective amount of the compounds defined by formulas (II) or (III).

[0118] In yet another aspect, the present invention also deals with any pharmaceutical compositions containing a therapeutically effective amount of any of the compounds defined by formulas (II) or (III), of which (IV), (V), (VI), (VII) are examples, and at least one pharmaceutically acceptable excipient, in which the N-acylhydrazone in question is the active component.

[0119] It is also noteworthy that, since the entire family of compounds described by formulas (II) and (III) is unprecedented, other potential uses, not detailed in the present patent application, are also part of the scope of the present invention. Those skilled in the art will appreciate that numerous variations regarding the scope of protection of the application are permitted and, thus, it reinforces the fact that the present invention is not limited to the particular configurations/embodiments described above.