WO2002092072A2 - Drugs for the treatment of the alzheimer disease - Google Patents

Abstract

Use for the treatment of the Alzheimer disease of compounds or salts thereof, having the following general formula (I): A-(B)b0-(C)c0-NO2, wherein A contains the radical of a drug having an antiinflammatory activity, B is a bivalent linking group the precursor thereof must satisfy the tests described in the application, C is a linking group as defined in the invention.

Description

DRUGS FOR THE ALZHEIMER DISEASE

* -k * -k *

The present invention relates to the use of a particular class of drug nitrooxyderivatives in the prophylaxis and therapy of the Alzheimer disease.

The Alzheimer is a disease which mainly affects old people. The progressive ageing of people determines a significant increase of the incidence of said disease: at present in the industrialized countries the people affected by the Alzheimer disease are about 13.5 millions.

The initial symptoms of the Alzheimer dementia include a decrease of the cognitive faculties. The main characteristics of the disease comprise the following: amyloid deposits (amyloid plaques) in the brain parenchyma and in the vessel wall, the main component of said plaques is the S-amyloid protein (Aβ); inflammatory process characterized by the activation of the microglia and by the presence of reactive astrocytes in the peri -plaque area with production of pro- inflam atory mediators, such as cytokines, NO.

Recently it has been observed that non steroidal inflammatory drugs (NSAIDs) can be useful in the disease prophylaxis and therapy (Stewart F , Neurology 48, 626-632,

1997). These compounds have a good antiinflammatory activity at brain level, however they have the drawback not to have a high inhibition of the amyloid plaque deposition. Therefore these compounds have a limited efficacy in preventing or in the treatment of the Alzheimer disease.

Another therapeutic approach for the prevention and the treatment of the Alzheimer disease is the administration of beta -amyloid vaccines (Schenk D. et Al . Nature 400 (6740) 173-7, 1999) or antibodies against amyloid β-peptide (Aβ) (F. Bard et Al . Nature vol. 6, 8, 916-919 2000). The vaccine action mechanism seems to be due, to the antibody reaction versus the beta-amyloid protein. The vaccine activity in the prevention, reduction and in the treatment of the amyloid plaque deposit is higher with respect to the antiinflammatory drugs. However vaccines show the drawback to have a high immunotoxicity due to the antibody hyperproduction (Schenk, see above) .

The need was felt to have available more effective compounds in the prevention, reduction and in the treatment of the deposit of the amyloid plaque with respect to the drugs of the prior art .

An object of the present invention is the use in the prophylaxis and treatment of the Alzheimer disease of compounds or salts thereof having the following general formula:

A-(B)_b0-(C)_c0-NO₂ (I) wherein: cO is an integer and is 0 or 1 , preferably 1 ; bO is an integer and is 0 or 1, with- the proviso that cO and bO cannot be contemporaneously equal to zero. A = R- _j-, wherein

R is the drug radical as defined below:

IV ) wherein :

G is one of the following groups : ^■CH=CH-

(Vg) M is one carbon or nitrogen atom; P is the following group:

(V) wherein: the carbon atom of formula (V) is in position 5 of the ring of formula (IV); Q is -CH- or one oxygen atorn;

<3A' PI./ <3_" Q-3 <3 ' ^are integers and independently the one from the other are 1 or 0 ; q₂ = q₃ = q₄ = 0 when the ring in formula (IV) is aromatic and Q = -CH- ; q₂ = q₃ = q₄ = 1 when the ring of formula (IV) is a saturated ring with 6 atoms wherein the heteroatom is Q = 0, and is in position 6 of the ring; when q_A = 1 and G is the group of formula (Vg) R_a and R_b, equal or different, are hydrogen, C_x-C₃ alkyl, preferably methyl ; R_c is hydrogen, C^-C_j alkyl, or the following radical:

(VI) wherein R_M, R₀, R_p, equal or different, can be H, halogen preferably chlorine, C₁-C₃ alkyl, preferably methyl, CF₃;

R„ is hydrogen or OCH₃ when the ring of fig. (IV) contains 6 atoms; or it is an electronic doublet when the ring with 6 atoms is aromatic and M = nitrogen; or it is a p. chlorobenzoyl radical when q_x = 0 and M = nitrogen and the ring of fig. (IV) is aromatic; or R_c and R_g taken together are such to form the following radical :

(VII) R_d in formula (IV) is hydrogen, hydroxyl, C_j-C,, alkyl, optionally branched, phenyl , or the following radical:

(VIII) R_dl = hydrogen when q₂ = 1 ;

R_e = hydrogen, halogen preferably F, or benzoyl; or R_d and R_e taken together are such to form the following radicals :

(IX) (X)

R_el = H when q₃ = 1 ; R_N = C^ - Cj alkyl preferably ethyl when q₄ - 1;

T, = (CO)_L or (X)_t , wherein X = 0, S, NR_1C, R_1C is H or a linear or branched alkyl, having from 1 to 5 carbon atoms, t and t' are integers and equal to zero or 1, with the proviso that t = 1 when t' = 0; t = 0 when t' = 1;

B = -T_B-X₂-T_BI- wherein

T_B and T_BI are equal or different;

T_B = (CO) when the reactive function in the precursor drug is -OH or -NH₂; T_B = X, as above, when the reactive function in the precursor drug is -COOH;

T_B: = (CO)_tx or (X)_txx, wherein tx and txx have the value of 0 or 1; with the proviso that tx = 1 when txx = 0, tx = 0 when txx = 1; X is as above defined;

X_? is a bivalent linking group as below defined;

C is the bivalent radical -T_c-Y- wherein: when bO = cO = 1: T_c = (CO) when tx = 0 , T_c = X when txx = 0, X being as above defined, when bO = 0 : T_c = ( CO ) when t = 0 , T_c = X when t ' = 0 , X being as above defined, when cO = 0: tx = 0, T_B = X = -0-; Y has one of the following meanings:

^YP ^: - rax

— [c_Jnϊχ-Y³ — [C]_ΠΠF°—

(III) wherein: nIX is an integer from 0 to 3 , preferably 1; nllX is an integer from 1 to 3 preferably 1; R_TIX, R_ττx. , R_Tιιχ' R_THX' ' equal to or different from each other are H or linear or branched C.-C₄ alkyl; preferably R_TTX , κ_TIX, , R_TITX, _THX' are π.,

Y³ is a heterocyclic ring containing one or two nitrogen atoms, said heterocyclic ring being a saturated, unsaturated or aromatic ring, having 5 or 6 atoms; or Y can be :

Y₀ , selected from the following: an alkylenoxy group R'O wherein R' is a linear or branched when possible C₁-C₂₀, preferably having from 2 to 6 carbon atoms, or a cycloalkylene having from 5 to 7 carbon atoms, in the cycloalkylene ring one or more carbon atoms can be substituted with heteroato s , the ring can have side chains of R' type, R' being as above; or one of the following groups: (CH₂- -CH₂-0)_n(7-

wherein nf ' is an integer from 1 to 6 preferably from 1 to 3;

-(CH-CH₂-0)_nf- -(CH₂- 0)_nf-

wherein R_1r = H, CH₃ and nf is an integer from 1 to 6; preferably from 2 to 4; or Y is Y_Ar and is selected from the following:

wherein n3 is an integer from 0 to 3 and n3 ' is an integer from 1 to 3 ;

wherein n3 and n3 ' have the above meaning; with the proviso that in formula (I) when bO = 0 and the bivalent radical Y of C is R'O, the radical R of formula (IV) of the drug is ferulic acid or flurbiprofen;

X₂, bivalent radical, is such that the corresponding precursor of B -T_B-X₂-T_BI- wherein the free valences of T_B and T_BI are each saturated with OZ, with Z or with -N(Z^T) (Z¹¹) , being: Z = H, C_ι-C₁₀, preferably C_x - C_s ^' alkyl linear or branched when possible,

Z¹, Z^ττ equal or different have^'' the Z values as above, depending on that T_B and/or T_BI = CO or X, in function of the values of t , t', tx and txx; it satisfies the following test (test 4): analytical determination carried out by adding aliquots of methanolic solutions at 10^"4 M concentration of the precursor of B to a methanolic solution of DPPH ( 2 , 2-diphenyl -1 -picryl hydrazyl ) ; after having maintained the solution at room temperature and sheltered from light for 30 minutes, the^' .absorbance of the test solution and of a solution containing^' only DPPH in the same amount is read, at the wave length of 517 nm; then the inhibition percentage of the precursor of B towards the radical production induced by DPPH is determined by means of the formula:

(1 - A_s/A_c)xl00 wherein A_s and A_c are respectively the absorbance values of the solution containing the test compound- -and DPPH and that of the solution containing only DPPH.

The acceptance criterion of the precursor compounds of B according to this test is the following: test 4 is satisfied by the precursor compounds of B when the inhibition percentage as above defined is higher than or equal to 50%.

When in formula (IV) q_A = 1 and G' is the group of formula (Vg) wherein R_a is methyl and R_b is hydrogen, q₂ = q„ = 0, M = C, and in formula (V) q_x = 1, Q = -CH- and q₃ = 0 , the ring of formula (IV) comprising M and Q is an aromatic ring having 6 carbon atoms and the other substituents are as defined hereinafter: when R_c = R_g = R_s- H and R_d is isobutyl , the so defined precursor drug of R is ibuprofen; when R_c = R_g = H and R_d is phenyl and R_e is F, the so defined precursor drug of R is flurbiprofen; when R_c = R_g = H and R_d and R_e form together the radical of formula (IX), the so defined precursor drug of R is naproxen; when R_c = R_g = R_e = H and R_d is the radical of formula (VIII), the so defined precursor drug of R is loxoprofen; when R_c = R_g = R_d = H and R_e = benzoyl , the so defined precursor drug of R is ketoprofen; when R_c = R_ff = H and R_d and R_e form together the radical of formula (X), the so defined precursor drug of R is carprofen; when in formula (IV) q_Λ = 0 , q₂ = q₄ = 0 , R_d = R_g = H, M = C, and in formula (V) q_j = 1, Q = -CH-, q₃ = 0, R_e = H, the ring of formula (IV) comprising M and Q is an aromatic ring having 6 carbon atoms and the other substituents are defined as hereinafter: when R_c is the radical of formula (VI) wherein R_M = R_p = H, R₀ = CF₃ and is in meta position with respect to the group- -NH- , the so defined precursor drug of R is the flufenamic acid; when R_c is the radical of formula (VI) wherein R_M = R_p = Cl and are in the two orto positions with respect to the -NH- group, R₀ = CH₃ and is in para position with respect to the -NH- group, the so defined precursor drug of R is the meclofenamic acid; when R_c is the radical of formula (VI) wherein R_M = H,

R_p = Cl and is in meta position with respect to the -NH- group, R₀ = CH₃ in orto position with respect to the -NH- group and to the chlorine atom, the so defined precursor drug of R is the tolfenamic acid; when in formula (IV) q_A = 0 , M = N; q₂ = q„ = 0, R_d = H; and in formula (V) q. = 1 , q₃ = 0 , R_e = H, Q = -CH- ; R_g is the free electronic doublet on the nitrogen atom, the ring of formula (IV) comprising M and Q is a pyridine ring, R_c is the radical of formula (VI) wherein R_M = R_P = H, R₀ = CF₃ and is in meta position with respect to the -NH- group, the so defined precursor drug of R is the niflumic acid; when in formula (IV) q_A = 1 and G is the group of formula (Vg) wherein R_a = R_b = H; M = C, R_d = R_g = H, q₂ = q₄ = 0; and in formula (V) q_x = 1 , Q = -CH- , R_e = H, q₃ = 0; the ring of formula (IV) comprising M and Q is an aroamtic ring having 6 carbon atoms; R_c is the radical of formula (VI) wherein R_M = R_p = Cl and are in the two ortho positions with respect to the -NH- group, R₀ = H; the so defined precursor drug of R is diclofenac; when in formula (IV) q_A = 1 and G is the group of formula (Vg) wherein R_a = R_b = H; M = C, q₂ = q₄ = 1 , R_d = R_dl = H, R_N = ethyl, and in formula (V) q_t = 1 , q₃ = 1 , Q = 0, R_e = R_el = H; the ring of formula (IV) comprising M and Q is a saturated ring having 6 atoms; R_g and R_c together form the radical of formula (VII), the so defined precursor drug of radical R is etodolac; when in formula (IV) q_A = 1 and G is the group of formula (Vg) wherein R_a = R_b = H; M = N q₂ = q₄ = 0 ; and in formula (V) q₃ = q_t = 0, the ring in formula (IV) comprising M corresponds to that of pyrrole; R_g = p. chlorobenzoyl ; R_c = CH₃; R_d together with R_e of formula (V) form the radical of formula (IX), the so defined precursor drug of radical R is indomethacin ; when in formula (IV) q_Λ = 1 and G = -HC=CH- , q₂ = q₄ = 0,

M = C, and in formula (V) q. = 1 , Q = -CH- , q = 0 and R_e = H, the ring of formula (IV) comprising M and Q is an aromatic ring having 6 carbon atoms; R_c = H, R_g = OCH₃ , R_d = OH, the so defined precursor drug of radical R is the ferulic acid of formula (IVA)

(IVA)

The precursor compound of B which satisfies test 4 is preferably selected from the following classes of compounds:

• aminoacids , selected from the following:: L-carnosine, anserine, selenocysteine , selenomethionine , penicillami- ne , N-acetylpenicillamine , cysteine, N-acetylcysteine, glutathione or esters thereof , preferably ethyl or isopropyl ester; hydroxyacids , selected from the following: gallic acid, ferulic acid, gentisic acid, citric acid, caffeic, dihydrocaffeic acid, p-cumaric acid, vanillic acid; aromatic and heterocyclic polyalcohols , selected from the following: nordihydroguaiaretic acid, quercetin, catechin, kaempferol, sulfuretine, ascorbic acid, isoascorbic acid, hydroquinone , gossypol, reductic acid, methoxyhydroquinone , hydroxyhydroquinone , propyl gallate, saccharose, 3 , 5-di- tertbutyl-4-hydroxybenzyl- thio glycolate, p-cumaric alcohol, 4 -hydrox -phenyl - ethylalcohol , coniferyl alcohol, allopurinol; compounds containing at least one free acid function, selected from the following: 3 , 3 ' - hiodipropionic acid, fumaric acid, dihydroxymaleic acid, edetic acid. The precursor compounds of B of the above mentioned groups are prepared according to methods known in the prior art and described, for example, in "The Merck Index", 12a Ed. (1996), herein incorporated by reference. Test 4 is a colorimetric test which allows to establish whether the precursors of B are able to inhibit the production of radicals from DPPH ( 2 , 2 -diphenyl-1-picryl - hydrazyl ) (M.S. Nenseter et Al . , Atheroscler. Thro b. 15, 1338-1344, 1995). 100 μM solutions in methanol of the tested substances are prepared, and an aliquot of each of said solutions is added to a 0,1 M DPPH solution in methanol. After having stored the solutions at room temperature and sheltered from light for 30 minutes, the absorbance is read at the wave length of 517 nm. The absorbance decrease with respect to that of the solution containing the same DPPH concentration is determined. The effectiveness of the tested compound in inhibiting the production of radicals is expressed by the following formula:

(1 - A_s/A_c)xl00 wherein A_s and A_c are respectively the absorbance values of the solution containing the tested compound together with DPPH and of the solution containing only DPPH.

The precursor of B satisfies test 4 if its effectiveness in inhibiting the radical production, as above defined, is equal to or higher than 50% at the indicated concentration (10^"4 M) .

Preferably Y³ is selected from the following:

( Y12 ) ( Y13 ) ( Y14 ) ( Y15 )

Preferably Y³ is an aromatic ring having 6 atoms, containing one nitrogen atom, said aromatic ring having the two free valences in position 2 and 6.

The preferred of Y³ is Y12 (pyridyl) susbstituted in position 2 and 6. The bonds can also be in asymmetric position. For example Y12 (pyridyl) can be substituted also in position 2 and 3; Yl (pyrazol) can be 3 , 5-disubstituted.

The precursors of Y as defined by formula (III) wherein the free valence of the oxygen is saturatd with H and the free valence of the end carbon is saturated either with a carboxylic or hydroxylic group, are products available on the market or can be obtained by methods known in the prior art .

In formula (I) the preferred precursors of B for the synthesis of the nitrooxyderivatives usable in the- present invention are the following: ferulic acid, N,acetylcysteine, cysteine, caffeic acid, hydrocaffeic and gentisic acid; the preferred precursor drugs of R are the following: ibuprofen, flurbiprofen, naproxen, ferulic acid of formula (IVA). The preferred compounds of formula (I) for the use according to the present invention are the following:

[ 1 , 1 ' -biphenyl ] -4 -acetic acid-, 2- fluoro- alpha-methyl - , 2 -methoxy-4- [ ( IE) -3- [ 4- (nitrooxy)butoxy] - 3-oxo- 1- propenyl ]phenylester (XII); alpha -methyl- 4- ( 2-methylpropyl )benzenacetic acid-, 2-me- thoxy- 4 - [ ( IE ) - 3 - [ 4 - ( itrooxy) utoxy] - 3 - oxo- 1-prope - nyl ] henylester (XIII);

6 -methoxy-alpha -methyl - 2 -naphthalenacetic acid-, 2- methoxy-4- [ (IE) -3- [4- (nitrooxy)butoxy] -3-oxo- 1-propenyl ] phenylester (XIV);

( S) -N-acetylcysteine-4- (nitrooxy)butylester- , (S) -6-me- thoxy-alpha-methyl-2-naphthalenacetate (XV) ; ( S ) -N-acetylcysteine-4- (nitrooxy )butylester- , 2-fluoro- alpha -methyl- [ 1, 1-biphenyl] -4 -acetate (XVI ) ; ( S ) -N-acetylcysteine-4- (nitrooxy )butylester- , l-(4- chlorobenzoyl) -5 -methoxy- 2 -methyl -IH-indol- 3 -acetate (XVII) ;

(S) -N-acetylcysteine-4- ( itrooxy)butylester- , alpha-methyl -4- ( 2-methylpropyl )benzeneacetate (XVIII) ; 2- [ ( 2 , 6-dichlorophenyl ) amino ]benzeneacetic acid-, 2-me- thoxy-4-[(lE)-3-[4-(nitrooxy) butoxy] - 3 - oxo - 1 -propenyl ] phenylester (XIX);

(S) -N-acetylcysteine-4- (nitrooxy)butylester- , 2- [(2,6- dichlorophenyl ) amino ]benzeneacetate ( XX ) ;

(XII;

;xv)

(XVI)

(XVII)

(XVIII)

(XIX)

(XX)

Other preferred compounds of the invention are those wherein in formula (I) the precursor drug of R has formula (IVA) , b0= 0 and cO = 1 and C is Y₀ or Y_Λr or Y_p, in particular the following compounds can be mentioned: trans 3- ( 4-hydroxy- 3 -methoxyphenyl ) - 2-propenoic acid-,

4- (nitrooxy) butyl ester (XXI)

(XXI) trans 3 -( 4 -hydroxy- 3 -methoxyphenyl )- 2-propenoic acid-, 3 - (nitrooxymethyl )phenyl ester (XXII)

(XXII) trans 3 -( 4-hydroxy- 3 -methoxyphenyl )- 2-propenoic acid-, 6- (nitrooxymethyl) -2-pyridinylmethylester hydrochloride (XXIII)

(XXIII) When the precursor drug is flurbiprofen and bO = 0 , cO = 1, Y of C is R'O, the following compound can be mentioned: 2-fluoro-alpha-methyl- [1,1' -biphenyl] -4 -acetic acid (nitrooxy butyl) ester (XXX):

(XXX) Other preferred compounds of the invention are those wherein in formula (I) the precursor drug of R has formula (IVA), b0= 1 and cO = 1 and C is Y₀ or Y_Ar, in particular the following compounds can be mentioned:

( S) -N-acetylcysteine-4- (nitroox )butylester- , trans- 3- ( 4-hydroxy- 3 -methoxyphenyl ) -2-propenoate (XXIV)

(XXIV) The preferred compound is the following: trans - 3 - ( 4-hydroxy- 3 -methoxyphenyl ) - 2-propenoic acid- , 2 -methoxy- 4- [ (IE) -3- [4- (nitrooxy)butoxy] - 3 -oxo- 1-propenyl ]phenylester (XXV)

(XXV) The nitrooxyderivatives of the compound of formula (IVA) are novel .

These compounds can be prepared by using for example the

^•If following synthesis schemes.

The reactions are carried out by well known methods of the prior art, which allow to obtain bonds among the precursor drug, the precursor compound of B and the bivalent radical C as above defined. la. When the drug has the general formula R-COOH, the functional group of the precursor compound of B which binds itself to the carboxylic function of the drug has formula XZ , X being as above defined and Z = H, the reactions which take place depend on the nature of the second reactive group present in the precursor compound of B. la.l When the second reactive group present in the precursor compound of B is a carboxylic group, the general synthesis scheme expects the initial formation of the acid halide R-COHal (Hal = Cl , Br) and the subsequent reaction with the HX group of the precursor compound of B:

RCOOH > RCOHal + H-X-X₂-COOH

R-T₁-T_B-X₂-COOH (IA.1) ^■₂ ' Ti , T_B being as above defined.

When in the two compounds under reaction other functional groups COOH and/or HX are present, they must be protected before the reaction according to the methods known in the prior art; for example as described in the volume by Th. W. Greene: "Protective groups in organic synthesis", Harward University Press, 1980.

The RCOHal acylhalide is prepared according to the methods- known in the prior art, for example by thionyl or oxalyl chloride, halides of P¹¹¹ or P in solvents inert under the reaction conditions, such as for example toluene, chloroform, DMF, etc.

In particular, if the HX group of the precursor compound of B is NH₂, or OH or SH, the precursor drug of formula R-COOH is first converted into the corresponding acyl halide RCOHal, as above mentioned, and then reacted with the HX group of the precursor compound of B in the presence of an organic base, such as triethylamine , pyridine, etc. using a solvent inert under the reaction conditions as toluene, tetrahydrofuran, etc. at a temperature in the range 0°C-25°C.

Alternatively to the previous synthesis, the precursor drug of formula R-COOH can be treated with an agent activating the carboxyl group selected from N,N'- carbonyldiimidazol (GDI), N-hydroxybenzotriazol and dicyclohexylcarbodii ide in solvent such as for example DMF, THF , chloroform etc. at a temperature in the range from -5°C to 50°C and the obtained compound reacted in situ with the reactive function of the precursor compound of B to obtain the compound of formula (IA.l). la.2 When the precursor compound of B contains two functional groups XZ, equal to or different from each other, X being as above defined and Z = H, the precursor drug having formula R-COOH is first treated with an agent activating the carboxyl groups, as described in la.l, and then with the precursor compound of B, after having protected one of the two reactive groups HX, for example with an acetyl group or tert-butyloxycarbonyl, restoring the initial function at the end of the synthesis. The scheme is the following: CDI, HX-X₂-X-G RCOOH → R-T₁-T_B-X₂-X-G →

R-T₁-T_B-X₂-XH (IA.2) wherein X, ^~~ _l , T_B, X₂ are as above defined and G is a protective group of the HX function.

2. Synthesis of the nitrooxyderivative

2a.1 When the compound obtained at the end of the previous step la. has formula (IA.1)=, the acid can be converted into the corresponding sodic salt and then one can follow the methods known in the prior art for preparing the final compound, for example according to one of the following synthesis schemes:

A.) R-T.-T_B-X₂-COONa + R₄-Xj_.-R₃

AgN0₃

R-T₁-T_B-X₂-T_BI-T_C-X_1A-R₃ (lA.lb) >

R-T₁-T_B-X₂-T_BI-T_c-Y-N0₂ wherein T_x, T_B, X₂, T_BI, T_c are as above, R₄ is selected from Cl , Br, Y is as above defined, X_1A is the radical Y without the oxygen atom, R₃ is Cl , Br, Iodine, OH. When R₃ = OH the compound of formula (lA.lb) is subjected to halogenation, for example with PBr₃, PC1_S, S0C1₂, PPh₃ + I₂, and then reacted with AgN0₃ in organic solvent such as acetonitrile, tetrahydrofuran . When R₃ is Cl , Br, Iodine, the compound of formula (lA.lb) is directly reacted with AgN0₃ as above mentioned.

B. ) R-T.-T_B-X₂-COONa + Hal-Y-N0₂ ^'

R-T₁-T_n-X,-T_BT-T-Y-NO_a C.)

R-T_T-T_B-X^COCI + R₅-X₁-R₃-→R-T₁-T_B-X₂-T_BI-T_C-X_1A-R₃ (lA.lc)

AgN0₃

R-T_l-T_B-X₂-T_BI-T_c-X_lA-R₃ >R-T₁-T_B-X₂-T_BI-T_c-Y-N0₂ wherein R₅ = OH or NHR_1C, R_1C, R₃ and the other symbols being as above defined.

The above shown reactions are well known in the prior art. See for example EP 670825 Bl , EP 722434 Bl and EP 759899 Bl in the name of the Applicant.

When X_1A is a linear C₄ alkyl, the corresponding acid R-T_x-T_B-X₂-COOH is reacted with triphenylphosphine in the presence of a halogenating agent such as CBr₄ or N-bromosuccinimide in tetrahydrofuran obtaining the compound (lA.lc) wherein R₃ = Br. a.2 When the compound obtained at the end of the previous step la. has formula (IA.2), the corresponding nitrooxyderivative is obtained by treating a halogen- carboxylic acid of formula Hal-X_1A-COOH, X_1A being as above, first with an agent activating the carboxyl group as described in 1A.1, and then with the compound of formula (IA.2), obtaining a halogen derivative, which is isolated and then dissolved in organic solvent (ref. paragraph 2a.1), and treated with silver nitrate. The global reaction scheme is the following:

1) GDI, 2) R-T.-T_B-X₂-XH Hal-X_1Λ-COOH - >

AgN0₃

R-T₁-T_B-X₂-T_BI-T_c-Y-N0₂ wherein T_t, T_B, X₂, T_BI, T_c, Y are as above.

Alternatively, the halide Hal-X₁-COCl can be used, wherein Hal is preferably bromine, which is reacted with the compound of formula (IA.2). lb. When the drug precursor has the reactive function HX, wherein X is as above defined, instead of a carboxylic group, the two functional groups present in the precursor compound of B can be the following: lb.l A carboxylic group, which reacts with the HX function of the drug precursor, and a group HX, the latter .reactive group of the precursor compound of B being equal to or different from the functional group of the drug precursor. The formula of the precursor compound of B is of the H-X-X₂-COOH type, wherein X and X₂ are as above.

The function H-X- of the precursor compound of B is protected according to the known methods in the prior art and the carboxyl group is reacted, as above indicated, according to the following scheme:

H-X-X₂-COOH G-X-X₂-COOH + R-XH >

R-T₁-T_B-X₂-X-G > R-T₁-T_a-X₂-X-H ( IB .1 )

At the end of the reaction the HX function- of the precursor compound of B is restored, lb.2 When the precursor compound of B contains two carboxylic groups, it is treated with an equimolar amount of an agent activating the carboxyl group under the conditions previously described in la.l, and then reacted with the reactive function HX of the drug precursor molecule. Possible other reactive functions of HX type present in the two compounds must be protected as previously indicated. Lastly a compound of formula R-T₁-T_B-X₂-COOH (IB.2) is obtained. b. Synthesis of the nitrooxyderivative. b.1 To obtain the final nitrooxyderivative starting from the compound of formula R-T_X-T_B-X₂-X-H (1B.1), obtained at the end of the synthesis described in lb.l, the compound (1B.1) is reacted with a halogenacid of formula Hal-X_lA- COOH which has been treated as previously described in paragraph la.l, or with the corresponding halogen acid chloride. The resulting compound is dissolved in organic solvent, for example acetonitrile or tetrahydrofuran, and reacted with silver nitrate. b.2 To obtain the final nitrooxyderivative starting from the compound of formula R-T₁-T_B-X₂-COOH (IB.2), obtained at the end of the synthesis described in lb.2, the acid is transformed into the corresponding sodic salt, it is reacted with a compound R₄-X_1A-R₃, previously defined in the reaction scheme A. of paragraph 2a.1, obtaining according to the same procedure therein mentioned the final nitrooxyderivative. Alternatively, when X_1A is a linear C₄ alkyl, the acid ( IB .2 ) is reacted with triphenylphosphine in the presence of a halogenating agent such as CBr₄ or N-bromosuccinimide in tetrahydrofuran and the resulting compound dissolved in organic solvent, for example acetonitrile, tetrahydrofuran, is reacted with silver nitrate. b.3 Alternatively to the synthesis procedure according to lb.l and 2b.1, it is possible to react in a first step the HX- function of the precursor compound of B HX-X₂- COOH with the acyl chloride of a halogenacid of formula Hal-X_1A-COCl , wherein Hal is preferably Br, and subsequently the carboxylic function of the so obtained compound with the drug precursor R-HX. In the third and last step the -Hal group is substituited with -ON0₂ according to the process described in 2b.1. The reaction scheme is the following:

HX-X₂ ^'-COOH + Hal-X_1A-COCl > Hal -X_1A-T_C-T_BI -X₂-COOH

R-XH

Hal-X₁÷T_c-T_B--X₂-COOH (2B.3) Hal -X_αA-T_c-T_BI -X₂-T_B-T_χ-R

AgN0₃

Hal-X_1A-T_c-T_BI-X₂-T_B-T₁-R > 0₂N-Y-T_c-T_BI-X₂-T_B-T₁-R wherein T_c, T_BI, T_B, T_x , X₂, X_1A, Y are as above defined.

In the previous scheme the nitration can be alternatively carried out on the acid compound of formula ( 2B.3 ) .

When the compounds of formula (I) usable in the present invention have one or more chiral centres, they can be in racemic form or as mixtures of diastereoisomers , as single enantiomers • , or single diastereoisomers; if they show geometric asymmetry, the compounds in the cis or trans form can be used.

When in the molecule of the compounds of formula (I) a salifiable functional group is present, for example an aminic or heterocyclic nitrogen, it is possible to use the corresponding salts of the above mentioned compounds, obtainable by reaction in organic solvent such as for example acetonitrile, tetrahydrofuran, with an equi olar amount of the corresponding organic or inorganic acid. Examples of usable organic acids are the following: oxalic, tartaric, aleic, succinic, citric acid.

Examples of usable inorganic acids are the following: nitric, hydrochloric, sulphuric, phosphoric acid. Nitric and hydrocloric acids are preferred.

It has been found that the nitrooxyderivatives used in the present invention are able to prevent the deposition of the amyloid plaque, with a higher efficacy than that of the products of the prior art. Their action mechanism is not clear yet since it has been found that they do not exert any inhibitory effect on the inflammatory process affecting the microglia. The invention results are still more surprising if one considers that the compounds used in the present invention are able to systemically release nitric oxide, which in the Alzheimer pathology is known as one of the pro- inflammatory mediators which are released further to the activation of the microglia. It was not predictable that the use of these compounds in the prophylaxis and therapy of the Alzheimer disease resulted effective.

Furthermore the compounds used in the present invention show very good tolerability, even after a long treatment. Due to the high efficacy and tolerability, they can be used also in very advanced pathology conditions.

The aforesaid compounds are formulated in the corresponding' pharmaceutical compositions for parenteral , oral use according to the techniques well known in the art, together with the usual excipients; see for example the volume "Remington's Pharmaceutical Sciences 15a Ed.".

The amount on a molar basis of the active principle in said formulations is the same or lower than the maximum posology indicated for the precursor drugs . Also higher doses can be used considering their very good tolerability. The daily doses of the precursor drugs can be found in the publications of the field, such as for example in "Physician's Desk reference".

Optionally, the use according to the present invention can be carried out by using the compounds of formula (I) in combination with one or more beta-amyloid based vaccines or antibodies against amyloid- β-peptides (Aβ) .

The vaccines are prepared by known methods, for example as described in the publication of Schenk et al . (1999) "Immunization with amyloid-beta attenuates Alzheimer-diseaselike pathology in the PDAPP mouse" Nature 400 ( 6740 ): 173 -7 and F. Bard, Nature vol. 6, 8, 916-919, 2000. In this case it is possible to reduce the administered vaccine amount with consequent reduction of the vaccine side effects of i munological nature as above indicated.

The following Examples illustrate the invention and are not limitative of its scope.

^•RXΆMPLE 1

Synthesis of (S)- N-acetylcysteine- 4- (nitrooxy)butylester,

- (S) - 6-methoxy- alpha-methyl- 2-naphthalenacetate of formula

(XV) a) Synthesis of ( S , ) -N-acetyl-S- ( 6 -methoxy-α-methyl- 2- naphthalen acetyl ) cysteine

To a solution of 6-methoxy-α-methyl-2-naphtalenacetic acid (10 g, 43.4 mmoles) in chloroform (100 ml) and N,N- dimethylformamide (6 ml) 1 , 1 ' -carbonyldiimidazol (GDI) (7.04 g, 43.4 mmoles) is added. After 15 minutes the obtained solution is treated with (S) -N-acetylcysteine (7.08 g, 43.4 mmoles) and it is left at room temperature for 12 hours. The reaction mixture is washed with HC1 5%, then with water and lastly with brine. The organic phase is anhydrified with sodium sulphate and then evaporated at reduced pressure. The ob- taind residue is purified by chromatography on silica gel elu- ting with ethyl acetate. 11.66 g of the expected product are obtained in the form of a white solid m.p. 122°C-126°C. H-NMR (CDC1₃): 7.71-7.65 (3H, m) , 7.34 (1H, dd) , 7.16-7.09 (2H, m) , 6.36 (1H, d) , 4.67 (1H, m) , 4.00 (1H, q) , 3 . 90 (3H, s) 3.32 (2H, t), 1.84 (3H, s), 1.59 (3H, d) . b) Synthesis of ( S) -N-acetyl -cysteine 4 - ( bromobutyl ester-S-

6 -methoxy-α-methyl - 2 -naphthalenacetate

To a solution of the compound sinthetized in the previous step (11.3 g, 30.1 mmoles) in tetrahydrofuran (200 ml), tri'- phenylphosphine (23.7 g, 90.3 mmoles) and carbon tetrabromide (28.85 g, 90.3 mmoles) are added. The reaction mixture is left under stirring for 24 hours at room temperature. The solvent is removed by evaporation at reduced pressure. The obtained crude product is purified by chromatography on silica gel elu- ting with n-hexane/ethyl acetate 7/3. 4 g of the ester are obtained in the form of a white solid having m.p. 67°C-71°C. c) Synthesis of I S ) - N-acetylcvsteine-4 - (nitrooxy)butylester , - (S) -6 -methoxy- alpha-methyl- 2 -naphthalenacetate

To a solution of the the ester obtained at the end of the previous step (1 g, 1.96 mmoles) in acetonitrile (20 ml) silver nitrate (0.66 g, 3.92 mmoles) is added. The reaction mixture is heated for 7 hours under reflux sheltered from light. The formed salt is removed by filtration and the solution is evaporated at reduced pressure. The obtained residue is purified by chromatography on silica gel eluting with n- hexane/ethyl acetate 7/3. 0.47 g of the final product are obtained in the form of a white solid having m.p. 56°C-59°C. 'H-NMR (CDC1₃) : 7.80-7.68 (3H, m) , 7.37(1H, d) , 7.20-7.13 (2H, ) , 6.12 (1H, d) 4.40 (2H, dd) , 4.26 (1H, m) , 4.15-3.87 (3H, m) , 3.92 (3H, s), 3.33 (2H, d) , 1.86 (3H, d) , 1.74-1.67 (4H, m) , 1.61 (3H, d). Elementary analysis:

Calculated C: 56.08% H: 5.73% N: 5.71% S: 6.51% Found C: 55.99% H: 5.68% N: 5.60% S: 6.35% EXAMPLE 2

Synthesis of (S) -N-acetylcysteine-4 - (nitrooxy)butylester, -alpha-methyl -4 -( 2-methylpropyl )benzeneacetate having formula (XVIII) (NO ibuprofen) a ) S^ynthesis of (S -N-acetyl-S- fα-methyl 4- ( 2-methylpropyl ) benzene 1 acetyl ) cysteine

To a solution of α-methyl [ 4- ( 2-methylpropyl )benzene] acetic acid (10 g, 48.48 mmoles) in^' chloroform (100 ml) and N,N- dimethylformamide (6 ml), 1, 1 ' -carbonyldiimidazol (7.86 g, 48.48 mmoles) is added. After 1 hour the obtained solution is treated with (S ) -N-acetylcysteine (7.91 g, 48.47 mmoles) and it is left at room temperature for 24 hours. The reaction mixture is washed with HCl 5%, then with water and lastly with brine. The organic phase is anhydrified with sodium sulphate and then evaporated at reduced pressure. The obtained residue is purified by chromatography on silica gel eluting with ethyl acetate. 13.3 g of the expected product are obtained in an oil form.

^XH-NMR (CDC1₃): 10.17 (1H, s) 7.13 (2H, d) 6.54 (1H, d), 4.76 (1H, m) , 3.93 (1H, q) , 3.42-3.30 (2H, m) , 2.49 (2H, d) , 1.85-1.83 (4H, m) , 1.55 (3H, d) , 0.93 (6H, d) . b) Synthesis of ( S) -N-acetylcysteine-4- (bromo)butylester . -alpha-methyl -4 - ( 2-methylpropyl )benzeneacetate

To a solution of the compound synthetized in the previous step (12.8 g, 36.4 mmoles) in tetrahydrofuran (100 ml) triphe- nylphosphine (28.65 g, 109.23 mmoles) and carbon tetrabromide (36.23 g, 109.23 mmoles) are added. The reaction mixture is left under stirring for 48 hours at room temperature. The solvent is removed by evaporation at reduced pressure. The obtained crude product is purified by chromatography on silica gel eluting with cyclohexane/ethyl acetate 1/1. 5.79 g of the ester are obtained in an oil form. c) Synthesis of ( S ) -N-acetylcysteine- 4 - (nitrooxyIbutylester , .-alpha-methyl -4 - (2-methylpropyl )benzeneacetate

To a solution of the ester obtained at the end of the previous step (5.5 g, 11.3 mmoles) in acetonitrile (100 ml) silver nitrate (2.69 g, 15.8 mmoles) is added. The reaction mixture is heated for 24 hours under reflux sheltered from light. The formed salt is removed by filtration and the solution is evaporated at reduced pressure. The obtained residue is purified by chromatography on silica gel eluting with cy- clohexane/ethyl acetate 7/3. 1.18 g of the expected product are obtained in an oil form.

^-NMR (CDC1₃): 7.27-7.09 (4H, m) , 6.19 (1H, d) , 4.75 (1H, ) , 4.47 (2H, t), 4.15-4.02 (2H, m) , 3.86 (1H, q) , 3.31 (2H, d) , 2.44 (2H, d), 1.89 (3H, d) , 1.86-1.76 (5H, m) , 1.51 (3H, d) , 0.89 (6H, d) . Elementary analysis:

Calculated C: 56.39% H: 6.88% N: 6.00% S: 6.84% Found C: 56.22% H: 6.79% N: 5.88% S: 6.92% EXAMPLE 3

Synthesis of (S)- N-acetylcysteine-4- (nitrooxy)butylester, 1- (4-chloro benzoyl) -methoxy- 2 -methyl -lH-indol- 3 -acetate of formula (XVII) a) Synthesis of ( S) -N-acetyl-S- [ 1- ( 4 - chlorobenzoyl ) -5-methoxy- 2 -methyl -lH-indol- 3 -acetyl 1 cysteine

To a solution of 1- ( 4 -chlorobenzoyl ) -5-methoxy- 2 -methyl - lH-indol- 3 -acetic acid (10 g, 28.00 mmoles) in chloroform (100 ml) and N,N-dimethylformamide (2 ml), 1 , 1 ' -carbonyldiimidazole (4.53 g, 28.00 mmoles) is added. After 1 hour the obtained solution is treated with (S) -N-acetylcysteine (4.56 g, 28.00 πimoles) and it is left at room temperature for 24 hours. The reaction mixture is washed with HC1 5%, then with water and lastly with brine. The organic phase is anhydrified with sodium sulphate and then evaporated at reduced pressure. The obtained residue is purified by chromatography on silica gel eluting with ethyl acetate. 7.79 g of the expected product are obtained in the form of a yellow solid having m.p. 129°C. ^lH-NMR (DMSO-d₆): 12.90 (1H, s), 8.21 (1H, d) , 7.69-7.64 (4H, ), 7.06 (1H, d), 6.96 (1H, d) , 6.73 (1H, dd) , 4.33 (1H, ) , 4.02 (2H, s), 3.77 (3H, s), 3.33-2.96 (2H, ) , 2.22 (3H, s), 1.78 (3H, s). b) Synthesis of (S)- N-acetylcysteine- 4 - (bromo )butylester , 1- ( 4-chloro benzoyl) -methoxy- 2 -methyl - 1H- indol- 3 -acetate

To a solution of the compound obtained in the previous step (3.09 g, 6.14 mmoles) in N,N dimethylformamide (50 ml), sodium ethylate (0.42 g, 6.14 mmoles) and, after 30 minutes, 1,4-dibromobutane (2.18 ml, 18.00 mmoli) dissolved in 25 ml of N, N dimethylformamide, are added. The reaction mixture is left under stirring for 20 hours at room temperature, then it is diluted with ethyl ether and washed with water. After the organic phase has been anhydrified with sodium sulphate the solvent is removed by evaporation at reduced pressure. The obtained crude product is purified by chromatography on silica gel eluting with eyelohexane/ethyl acete 1/1. 1.7 g of the ester are obtained in the form of a yellow solid having m.p. 130°C-134°C. c) Synthesis of (S)- N-acetylcysteine-4- (nitrooxy)butylester , 1- ( 4 -chlorobenzoyl) -methoxy- 2 -methyl -lH-indole- 3 -acetate

To a solution of the ester obtained at the end of the previous step (1.6 g, 2.5 mmoles) in acetonitrile (30 ml) silver nitrate (0.6 g, 3.51 mmoles) is added. The reaction mixture is heated for 8 hours under reflux sheltered from light. The formed salt is removed by filtration and the solution is evaporated at reduced pressure. The obtained residue is purified by chromatography on silica gel eluting with eyelohexane/ethyl acetate 4/6. 1.2 g of the final product are obtained in an oil form. ^-NM (CDCI₃): 7.66 (2H, d), 7.48 (2H, d), 6.90 (2H, ) , 6.68

(IH, in) , 6.14 (IH, d) , 4.77 (IH, ) , 4.43 (2H, t), 4.08 (2H, ) , 3.87 (2H, s), 3.83 (3H, s), 3.34 (2H, d) , 2.38 (3H, s),

1.90 (3H, s), 1.78-1.70 (4H, ) .

Elementary analysis:

Calculated C: 54.24% H: 4.88% N: 6.80% S: 5.17% Cl : 5.72%

Found C: 54.32% H: 4.93% N: 6.91% S: 5.13% Cl : 5.84%

EXAMPLE 4

Synthesis of (S)- N-acetylcysteine-4- (nitrooxy)butylester , 2- fluoro-alpha-methyl- [1 ,1-biphenyl] -4-acetate of formula (XVI)

The compound is synthetized according to the procedure described in Example 1. The substance appears as an oil. Yield: 26%. ^lH-NMR (CDC1₃): 7.41-7.38 (6H, m) , 7.10 (2H, m) , 6.22 (IH, d) , 4.78 (IH, ) , 4.46 (2H, t), 4.13 (2H, t), 3.92 (IH, q) , 3.36 (2H,^'d), 1.93 (3H, d), 1.76 (4H, -d), 1.55 (3H, d). Elementary analysis:

Calculated C: 56.91% H: 5.37% N: 5.55% S: 6.33% F: 3.75% Found C: 56.99% H: 5.41% N: 5.66% S: 6.41% F: 3.83% EXAMPLE 5

Synthesis of alpha-methyl - 4- ( 2-methylpropyl )benzeneacetic acid, 2 -methoxy- 4- [ (IE) -3- [4- (nitrooxy)butoxy] -3 - oxo- 1 -prope- nyl]phenylester of formula (XIII) a) Synthesis of the trans -3 - [ 4- [ -methyl -r 4- ( -2-methylpropyl ) benzene ]acetyloxy] -3 -methoxyphenyl] -2-propenoic acid

To a solution of -methyl- [4- (2 -methyl ropyl)benzene]a- cetic acid (5.03 g, 24.4 mmoles) in tetrahydrofuran (100 ml) and N,N-dimethylformamide (5 ml) 1 ,1- carbonyldiimidazol (4.25 g, 24.8 mmoles) is added. After 1 hour the obtained solution is treated with ferulic acid (4.90 g, 25 mmoles), sodium ethy- late (89 mg) is added and the solution is left at room temperature under stirring for 12 hours. The reaction mixture is washed with HCl 5%, then with water and lastly with brine. The organic phase is anhydrified with sodium sulphate and evaporated at reduced pressure.

The obtained residue is purified by chromatography on silica gel eluting with ethyl acetate/n-hexane 7/3. 5.1 g of the expected product are obtained as a white solid having m.p.

131°C-137°C.

'H-NMR (CDC1₃): 7.72 (IH, d) , 7.32 (2H, dd) , 7.26 (IH, m) , 7.16-7.07 (4H, m) , 6.98 (IH, d) , 6.37 (IH, d), 3.99 (IH, q) , 3.73 (3H, s), 2.47 (2H, d) , 1.88 (IH, m) , 1.63 (3H, d) , 0.92 (6H, d). b synthesis of benzenacetic acid, alpha-methyl - 4- ( 2-methylpropyl ) , 2 -methoxy- 4- \ ( IE) -3- [4- (bromo) butoxy] - 3 -oxo- 1-propenyl ]phenylester

To a solution of the compound synthetized in the previous step (5.33 g, 14 mmoles) in N,N-dimethylformamide (130 ml) sodium ethylate (1.2 g, 16 mmoles) is added, under stirring. After 1 hour to the obtained mixture 1, 4-dibromobutane (10 g, 46 mmoles) is added and it is let react at room temperature for 12 hours. The reaction mixture is washed with HCl 5%, then with water and lastly with brine; the organic phase is anhydrified with sodium sulphate and evaporated at reduced pressure. The obtained residue is purified by chromatography on silica gel eluting with n-hexane/ethyl acetate 8/2. 4.46 g of the expected product are obtained. c) Synthesis of benzenacetic acid, alpha-methyl-4- f 2-methyl - propyl ) , 2 -methoxy- 4- [ (IE) -3- [4- (nitrooxy)butoxy] - 3-oxo- 1- propenyl ] phenylester

To a solution of the compound synthetized in the previous step (4 g, 7.72 mmoles) in acetonitrile (70 ml) silver nitrate (2.58 g, 15 mmoles) is added. The reaction mixture is heated under reflux for 2 hours sheltered from light. At the end the formed salt is removed by filtration and the solution is evaporated at reduced pressure. The recovered residue is purified by chromatography on silica gel eluting with n-hexane/ethyl acetate 8/2. 2.4 g of the expected product are obtained as an oil .

^XH-NMR (CDC1₃): 7.62 (IH, d) , 7.32 (2H, d), 7.15 (2H, d), 7.16- 7.05 (2H, m) , 6.96 (IH, d), 6.35 (IH, d), 4.51 (2H, t), 4.24 (2H, t), 3.99 (IH, q), 3.74 (3H, s), 2.48 (2H, d) , 1.89-1.83 (5H, ) , 1.62 (3H, d) , 0.92(6H, d) . Elementary analysis:

Calculated C: 64.91% H: 6.66% N: 2.82% Found C: 64.83% H: 6.52% N: 2.69%

EXAMPLE 6

Synthesis of [1, 1' -biphenyl] -4 -acetic acid, 2-fluoro-alpha - methyl, 2 -methoxy- 4- [ (IE) -3- [4- (nitrooxy)butoxy] -3 -oxo- 1-pro^¬ penyl]phenylester of formula (XII) (NO-flurbiprofen)

The compound is synthetized according to the procedure described in Example 5. The global yield of the process is 32%. The substance appears as an amorphous solid. ^lH-NMR (CDCI₃): 7.40-7.25 (9H, m) , 7.07-7.01 (2H, d), 6.98 (IH, m) , 6.38 (IH, d) , 4.44 (2H, t), 4.46 (2H, t), 4.21 (2H, t), 4.04 (IH, q), 3.73 (3H, s), 1.72 (4H, ) , 1.65 (3H, d) . Elementary analysis:

Calculated C: 64.79% H: 5.25% N: 2.62% F: 3.53% Found C: 64.85% H: 5.31% N: 2.74% F: 3.48% EXAMPLE 7

Evaluation of the effect of ibuprofen and of NO-flurbiprofen (ex. 6) on the reduction of the amyloid deposits (amyloid plaques) (Protein Aδ) in the front cerebral cortex and on the ac- tivation of the microglia measured in the frontal cerebral cortex.

In this experiment transgenic rats (APPM-PS1M) having human genes and mutated by the protein precursor of the β- a yloid protein (APP, from which the AJ3 protein of the amyloid plaques forms by proteolysis) and by the preseniline- 1 proteine(PSl ) have been used. Mutations in these proteins cause the Alzheimer dementia - in some families wherein the disease presents a dominant autosomic character. Rats carriers of the double- transgene APP mutated + PS-1 mutated (APPM/PS1M) represent a very good model for the study of Alzheimer dementia since they develop amyloid plaques and neu- roinflammation like those found in the human pathology (Hol- co b L. et Al. Nat. Med. 4:97 (1998)).

Three groups- each formed by 12 transgenic rats (APPM/PS1M) , 7 months old at the beginning of the experiment, received together with the daily diet, ibuprofen and, respectively, NO-flurbiprofen (ref. Ex. 6).

The administered pro die dose of each compound was 60 mg/kg for 5 months . The third group was the control group and received only the daily diet. At the end of the fifth month the animals were sacrificed by intra-peritoneal injection of pentobarbital (100 mg/kg). The brains were removed and the two hemispheres separated. The hemispheres were first treated for 24 hours with a paraformaldehyde solution (4% by volume), then for a period of 8 hours each, with solutions at increasing concentrations of phosphate buffer of Soreson, respectively at 10%, 20% and 30%. The hemispheres have then been frozen and dissected along an horizontal plane and the sections have been maintained at 4°C in DPBS (Dulbecco phosphate buffer saline) with sodium azide.

The entity of the amyloid deposits has been evaluated on a part of the brain sections obtained by coloration with Congo Red (Sheehan DC, Hrapchak BB , eds . Theory and Practice of Histotechnology, 2^nd ed. Mosby, St. Louis (MO), 1980, pp. 177-178; Thompson SW, ed. Selected Histoche ical and Histo- pathological Methods. Charles C. Thomas, Springfield (IL), 1966, pp. 402-405), and on a further part of the brain sections by treatment with polyclonal antibody specific versus peptide AS, in order to identify by a susequent immunochemi- cal method the AS deposits.

Another part of the sections obtained from the frontal cortex has been analyzed by immunohistochemical analysis by using antibodies directed against microglial activation indicators: anti-MHC-II, directed against the hystocompatibility complex of type II, anti-CRIII which recognizes the complement receptor 3. Expression of these indicators results increased in the activated microglia. The microglia presence has been quantified by videodensitometric analysis and the positive microglial cells for MHC-II have been counted in various areas of each brain section and the results have been expressed as average number of positive MHC-Ii cells for tissue section. The results are reported in Tables 1 and 2.

The results reported in Table 1 show that NO- flurbiprofen induces a significant reduction of the amyloid plaque deposits (Aβ deposits) in treated animals with respect to ibuprofen.

The ibuprofen activity results remarkably lower than that of the compounds according to the present invention.

The results reported in Table 2 are expressed as a ratio between the average number of activated microglial cells (po^¬ sitive MCH-II) counted in the cerebral sections of the three groups of animals and the average number of activated microglial cells counted in the cerebral sections of the control group. Said results show that in the group of rats treated with NO-flurbiprofen the number of the microglial cells is about 25 times higher than that of the controls and that in the group treated with ibuprofen the number of the activated cells is about 6 times higher than that of the controls. EXAMPLE 8

Evaluation of the gastric damages induced by flurbiprofen and ibuprofen with respect to the corresponding nitrooxyderivati- ves according to the present invention

The gastric tolerability of these drugs has been evaluated in rats (groups of 10 rats each) treated for short or long period, according to conventional protocols, respectively with NO-flurbiprofen as above defined, an equimolar dose of flurbiprofen, or with ibuprofen or with an equimolar dose of NO-ibuprofen.

The administered doses and the obtained results are reported in Table 3 and show that administration of flurbipro- fen causes gastric damages, while NO-flurbiprofen does not damage the gastric mucosa, and is more tolerated. EXAMPLE 9

Efficacy of NO- flurbiprofen (ex. 6), of 4-nitrooxy butyl derivative of flurbiprofen (N0-C„-flurbiprofen) , of 4- nitrooxybutyl derivative of aspirin (NO-ASA) and of flurbiprofen in inhibiting the cerebral neurodegeneration in rats treated with LPS

The nitrooxybutyl derivative of aspirin (NO-ASA) and the nitrooxybutyl derivative of flurbiprofen (NO-C₄- flurbiprofen) have been synthetized according to the method reported in the patent application WO 95/30641 in the name of the Applicant .

72 male rats F-344, 3 -months old, have been divided in 5 groups, which were chronically infused with LPS ( lypopolysac - charide) for 30 days and received once a day for the same period of time, by subcutaneous injection respectively NO-ASA (90 mg/kg equivalent to 302 μmoles/Kg) , NO-flurbiprof n (14 μmoles/kg), NO-C₄- flurbiprofen (15 mg/Kg equivalent to 41.5 umoles/kg), flurbiprofen (3 mg/Kg equivalent to 12.3 μmoles/kg), or only the same volume of solvent (controls). The solvent was formed by a mixture of dimethylsolphoxi- de/ethanol/castor oil 20/5/75 by volume.

At the end rats were sacrificed by lethal injection with pentobarbital . Fixation procedure for cerebral tissues

The brain of each rat was perfused in situ at first with a cold saline solution containing 1 U/ml of heparin, then with paraformaldehyde 4% in phosphate buffer 0,1 M (pH 7.4). The brains have been dissected, further on fixed for 1 h in the same solutions and incubated for one night in a cryoprotective solution containing 20% by weight of sucrose. The frozen tissues were gradually warmed up to -20°C and front serial sections were cut by a cryostat. The sections have been collected in phosphate buffer, then immediately used or otherwise maintained overnight.

The sections were washed and incubated in phosphate buffer and incubated overnight at room temperature with primary antibodies for specific epitoms. The activated microglia was visualized by using the antibody OX- 6 directed against the hi- stocompatibility complex of class II (MHC-II). Sections have been incubated for 1 h with the secondary biotinylated antibody (mouse anti-IgG, obtained in horse) and then with avidin conjugated with peroxidase (1 h) . Then, the sections were treated for 1-5 min with 0.05% of a solution of 3,3'- diaminobenzidine tetrahydrohydrocloride, which is the peroxidase substratum. The dye was removed by washings with PBS.

The brain sections were then analyzed by microscopy. The number of positive microglial cells for OX- 6 in the dentate ring and in the CAl-4 areas of the hippocampus were counted in identical brain sections from each rat.

The results , expressed as inhibition percentage of the neurodegenerative process with respect to the controls, are reported in Table 4 and show that the nitrooxyderivatives N0- flurbiprofen and NO-C₄-flurbiprofen according to the invention are more effective in inhibiting the neurodegenerative process induced by LPS with respect to NO-ASA. Flurbiprofen at the tested dose, that is comparable with that of NO-C₄- flurbiprofen, is ineffective an caused gastric lesions in the animals. The NO-ASA activity is on the contrary very lower than that of the two previous compounds .

Table 1

¹ Coloration with congo red;

² Dosage S I by i unocytochemical method

Table 2

Table 3

Table 4

Claims

CLAIMS Use for the preparation of drugs in the prophylaxis and treatment of the Alzheimer desease of compounds, or salts thereof, having the following general formula:

A-(B)_b0-(C)_c0-NO₂ (I) wherein: cO is an integer and is 0 or 1, preferably 1; bO is an integer and is 0 or 1, with the proviso that cO and bO cannot be contemporaneously equal to zero. A = R-T_x-, wherein

R is the drug radical as defined below:

(iv) wherein:

G is one of the following groups ^■CH=CH- ,

a

(Vg) M is one carbon or nitrogen atom; P is the following group:

(V) wherein: the carbon atom of formula (V) is in position 5 of the ring of formula (IV); Q is -CH- or one oxygen atom;

<3_A' <3_I ^₂ > <3₃' <3₄' ^are integers and independen^¬ tly the one from the other are 1 or 0 ; q₂ = q₃ = q₄ = 0 when the ring in formula (IV) is aromatic and Q = -CH- ; q₂ = q₃ = q₄ = 1 when the ring of formula (IV) is a saturated ring with 6 atoms wherein the heteroatom is Q = 0, and is in position 6 of the ring; when q_A = 1 and G is the group of formula (Vg) R_a and R_b, equal or different, are hydrogen, C₁-C₃ alkyl, preferably methyl;

R_c in formula (IV) is hydrogen, C_x-C₃ alkyl, or the following radical:

(vi; wherein R_M, R₀, R_p, equal or different, can be H, halogen preferably chlorine, C₁-C₃ alkyl preferably methyl, CF₃; R_g is hydrogen or -OCH₃, when the ring of fig. (IV) has 6 atoms; or it is an electronic doublet when the ring having 6 atoms is aroamtic and M = nitrogen; or it is a p. chlorobenzoyl radical when q_x = 0 and M = nitrogen and the ring of fig. (IV) is aromatic; or R_c and R_g taken together are such to form the following radical :

(VII) R_d in formula (IV) is hydrogen, hydroxyl, C₁-C₄ alkyl, optionally branched, phenyl , or the following radical :

(VIII) R_dl = hydrogen when q₂ = 1 ;

R_e (formula V) = hydrogen, halogen preferably F, or benzoyl ; or

R_d and R_e taken together are such to form the fol - lowing radicals:

(IX) (X)

R_el (formula V) = H when q₃ = 1; R_N (formula IV) = C₁-C₃ alkyl preferably ethyl when q₄ = i;

T_τ = (CO)_t or (X)_t., wherein X = 0, S, NR_1C, R_xc is H or a linear or branched alkyl, having from 1 to 5 carbon atoms, t and t' are integers and equal to zero or 1, with the proviso that t = 1 when t' = 0; t = 0 when t' = 1; B = -T_B-X₂-T_BI- wherein

T_B and T_BI are equal or different;

T_B = (CO) when the reactive function in the precursor drug is -OH or -NH₂; T_B = X, as above, when the reactive function in the precursor drug is -C00H; T_BT= (CO)_tx or (X)_txx, wherein tx and txx have the value of 0 or 1; with the proviso that tx = 1 when txx = 0, tx = 0 when txx = 1; X is as above defined; X₂ is a bivalent linking group as defined below; C is the bivalent radical -T_c-Y- wherein when bO = cO = 1: T_c = (CO) when tx = 0 , T_c = X when txx = 0, X being as above defined, when bO = 0: T_c = (CO) when t = 0 , T_c = X when t' =

0, X being as above defined, when cO = 0: tx = 0, T_BI = X = -0-;

Y has one of the following meanings: Y-

wherein: nix is an integer from 0 to 3 , preferably 1; nllX is an integer from 1 to 3 preferably 1 ; R_TIX, R_TIX, , _ru_x, R_TIIX' equal to or different from each other are H or linear or branched C₁-C₄ alkyl; preferably R_TIX, R_TIX. , ι_I , R_Tιιx' ^are EL Y³ is a heterocyclic ring containing one or two nitrogen atoms, said heterocyclic ring being a saturated, unsaturated or aromatic ring, having 5 or 6 atoms ; or Y may be : Y₀ , selected from the following: an alkylenoxy group R'O wherein R' is a linear or branched when possible C₁-C₂₀, preferably having from 2 to 6 carbon atoms , or a cycloalkylene having from 5 to 7 carbon atoms , in the cycloalkylene ring one or more carbon atoms can be substituted with he- teroatoms, the ring can have side chains of R' type, R' being as above; or one of the following groups:

(CH₂- CH₂- O)nf_τ

wherein nf ' is an integer from 1 to 6 preferably from 1 to 3 ; (CH-CH₂-0)_nf- -(CH₂-CH-0)_nf-

Rι, wherein R_lf = H, CH₃ and nf is an integer from 1 to 6; preferably from 2 to 4; or Y is Y_Ar and is selected from the following:

wherein n3 is an integer from 0 to 3 and n3 ' is an integer from 1 to 3 ;

wherein n3 and n3 ' have the above meaning; with the proviso that in formula (I) when bO = 0 and the bivalent radical Y of C is R'O, the radical R of formula (IV) of the drug is ferulic acid or flurbiprofen; X₂, bivalent radical, is such that the corresponding precursor of B -T_B-X₂-T_BI- wherein the free valences of T_B and

T_BI are each saturated with OZ, with Z or with -N(Z^I)(Z II • being:

Z = H, C_x-C₁₀ , preferably a linear or branched when possible

alkyl,

Z^τ, Z^ιτ equal or different have the values of Z as above, depending on that T_B and/or T_BI = CO or X, in function of the values of t, t' , tx and txx; it satisfies the following test (test 4): analytical de- termination carried out by adding aliquots of methanolic solutions at- 10^"4 M concentration of the precursor of B to a methanolic solution of DPPH ( 2 , 2-diphenyl -1-picryl hydrazyl); after having maintained the solution at room temperature and sheltered from light for 30 minutes, the absorbance of the test solution and of a solution containing only DPPH in the same amount is read, at the wave length of 517 nm; then the inhibition percentage of the precursor of B towards the radical production induced by DPPH is determined by means of the formula:

(1 - A_s/A_c)xl00 wherein A_s and A_c are respectively the absorbance values of the solution containing the test compound and DPPH and that of the solution containing only DPPH.

The acceptance criterion of the precursor compounds of B according to this test is the following: test 4 is satisfied by the precursor compounds of B when the inhibition percentage as above defined is higher than or equal to 50%. Use according to claim 1, wherein: when in formula (IV) q_A = 1 and G is the group of formula (Vg) wherein R_a is methyl and R_b is hydrogen, q₂ = q₄ = 0, M = C, and in formula (V) q_x = 1, Q = -CH- and q₃ = 0, the ring of formula (IV) comprising M and Q is an aromatic ring having 6 carbon atoms and the other substi - tuents are as defined hereinafter: when R_c = R_g = R_e= H and R_d is isobutyl, the so defined precursor drug of R is ibuprofen; when R_c = R_g = H and R_d is phenyl and R_e is F, the so defined precursor drug of R is flurbiprof n; when R_c = R_g = H and R_d and R_e form together the radical of formula (IX), the so defined precursor drug of R is naproxen; when R_c = R_g = R_e = H and R_d is the radical of formula (VIII), the so defined precursor drug of R is lo- xoprofen; when R_c = R_g = R_d = H and R_e = benzoyl , the so defined precursor drug of R is ketoprofen; when R_c = R_g = H and R_d and R_e form together the ra^¬ dical of formula (X) , the so defined precursor drug of R is carprofen; when in formula (IV) q_A = 0, q₂ = q₄ = 0, R_d = R_g = H, M = C, and in formula (V) q_x = 1, Q = -CH- , q₃ = 0 , R_e = H, the ring of formula (IV) comprising M and Q is an aromatic ring having 6 carbon atoms and the other substi^¬ tuents are as defined hereinafter: when R_c is the radical of formula (VI) wherein R_M = R_p = H, R₀ = CF₃ and is in meta position with respect to the -NH- group, the so defined precursor drug of R is the flufenamic acid; when R_c is the radical of formula (VI) wherein R_M = R_p = Cl and are in the two ortho positions with re^¬ spect to the -NH- group, R₀ = CH₃ and is in para position with respect to the -NH- group, the so defined precursor drug of R is the meclofenamic acid; when R_c is the radical of formula (VI) wherein R_M = H, R_p = Cl and is in meta position with respect to the -NH- group, R₀ = CH₃ in orto position with re- sepct to the -NH- group and to the chlorine atom, the so defined precursor drug of R is the tolfenamic acid; when in formula (IV) q_A = 0 , M = N; q₂ = q₄ = 0 , R_d = H; and in formula (V) q. = 1 , q₃ = 0 , R_e = H, Q = -CH- ; R_g is the free electronic doublet on the nitrogen atom, the ring of formula (IV) comprising M and Q is a pyridine ring, R_c is the radical of formula (VI) wherein R_M = R_p = H, R₀ - CF₃ and is in meta position with respect to the -NH- group, the so defined precursor drug of R is the ni - flumic acid; when in formula (IV) q_A = 1 and G is the group of formula (Vg) wherein R_a = R_b = H; M = C, R_d = R_g = H, q₂ = q₄ = 0; and in formula (V) q_x = 1, Q = -CH- , R_e = H, q₃ = 0; the ring of formula (IV) comprising M and Q is an aromatic ring having 6 carbon atoms; R_c is the radical of formula (VI) wherein R_M = R_p = Cl and are in the two orto positions with respect to the -NH- group, R₀ = H; the so defined precursor drug of R is diclofenac; when in formula (IV) q_A = 1 and G is the group of formula (Vg) wherein R_a = R_b = H; M = C, q₂ = q₄ = 1 , R_d = R_dl = H, R_M = ethyl, and in formula (V) q_x = 1, q₃ = 1, Q = 0, R_e = R_eX = H; the ring of formula (IV) comprising M and Q is a saturated ring having 6 atoms; R_g and R_c together form the radical of formula (VII), the so defined precursor drug of radical R is etodolac; when in formula (IV) q_A = 1 and G is the group of formula (Vg) wherein R_a = R_b = H; M = N q₂ - q₄ = 0 ; and in formula (V) q₃ = q_x = 0 , the ring in formula (IV) comprising M corresponds to that of pyrrol; R_g = p. chlorobenzoyl; R_c = CH₃; R_d together with R_e of formula (V) form the radical of formula (IX), the so defined precursor drug of radical R is indomethacin.

Use according to claim 1, wherein when in formula (IV) q_A = 1 and G = -HC=CH- , q₂ = q₄ = 0, M = C, and in formula (V) q_x = 1, Q = -CH- , q₃ = 0 and R_e = H, the ring of formula (IV) comprising M and Q is an aromatic ring having 6 carbon atoms; R_c = H, R_g = OCH₃, R_d = OH, the so defined precursor drug of radical R is the ferulic acid of formula (IVA)

(IVA) 4. Use according to claims 1-3, wherein the precursor compound of B which satisfies test 4 is selected from the following classes of compounds : a inoacids, selected from the following: L- carnosine, anserine, selenocysteine, selenomethioni- ne, penicillamine, N-acetylpenicillamine, cysteine, N-acetylcysteine, glutathione or esters thereof, preferably ethyl or isopropyl ester; hydroxyacids, selected from the following: gallic acid, ferulic acid, gentisic acid, citric acid, caffeic, dihydrocaffeic acid, p-cumaric acid, vanillic acid; aromatic and heterocyclic polyalcohols , selected from the following: nordihydroguaiaretic acid, quer- ce in, catechin, kaempferol, sulphuretin, ascorbic acid, isoascorbic acid, hydroquinone , gossypol, re- ductic acid, methoxyhydroquinone , hyd oxyhydroqui.no- ne , propyl gallate, saccharose, 3 , 5-di-tertbutyl-4- hydroxybenzylthio glycolate, p-cumaric alcohol, 4- hydroxy-phenylethylalcohol , coniferyl alcohol, allo- purinol ; compounds containing at least one free acid function, selected from the following: 3,3'- thiodipropionic acid, fumaric acid, dihydroxymaleic acid, edetic acid.

Use according to claims 1-4, wherein Y³ in formula (III) is selected from the following:

(Yl) (Y2) (Y3) (Y4) (Y5) (Y6)

(Y7) (Y8) (Y9) (Y10) (Yll)

(Y12) (Y13) (Y14) (Y15) Use according to claim 5 , wherein Y³ is an aromatic ring having 6 atoms, containing one nitrogen atom and having the two free valences respectively in position 2 and 6. Use according to claims 6, wherein Y³ is Y12 (pyridyl) substituted in position 2 and 6 or having the two bonds also in asymmetric position. Use according to claims 1-7, wherein the precursors of B of formula (I) for the synthesis of the nitrooxyderivati- ves usable in the present invention are the following: ferulic acid, N-acetylcysteine, cysteine, caffeic acid, hydrocaffeic and gentisic acid; and the precursor drugs of R are the following: ibuprofen, flurbiprofen, napro- xen, ferulic acid.

Use according to claims 1-8, wherein the compounds of formula (I) are the following:

[1,1' -biphenyl] -4 -acetic acid-, 2-fluoro-alpha-methyl- , 2-methoxy-4- [ (IE) -3- [4- (nitrooxy)butoxy] -3-oxo-l- propenyl ]phenylester (XII ) ; alpha-methyl-4- ( 2-methylpropyl ) benzenacetic acid-, 2 -methoxy- 4- [ (IE) -3- [4- (nitrooxy)butoxy] - 3 -oxo- 1-propenyl ]phenylester (XIII);

6-methoxy-alpha-methyl-2-naphthalenacetic acid-, 2- ethoxy- 4 - [ ( IE ) - 3 - [ 4 - (nitrooxy) utoxy] - 3 -oxo- 1 -propenyl ] phenylester (XIV) ;

(S ) -N-acetylcysteine-4- (nitrooxy)butylester- , (S)-6- methoxy- alpha-methyl- 2-naphthalenacetate (XV) ;

(S) -N-acetylcysteine-4- (nitrooxy)butylester- , 2- fluoro- alpha-methyl- [ 1,1-biphenyl ] -4-acetate (XVI) ;

(S) -N-acetylcysteine-4- (nitrooxy)butylester- , l-(4- chlorobenzoyl ) - 5 -methoxy- 2 -methyl - IH- indol - 3 -acetate (XVII);

(S) -N-acetylcysteine-4- (nitrooxy)butylester- , alpha- methyl-4- (-2-methylpropyl )benzeneacetate (XVIII) ;

2- [ ( 2 , 6-dichlorophenyl)a ino]benzeneacetic acid-, 2- methoxy- 4- [ (IE) -3- [4- (nitrooxy)bu oxy] - 3 -oxo- 1 -propenyl ] phenylester (XIX);

(S) -N-acetylcysteine-4- (nitrooxy)butylester- , 2- [ (2 , 6-dichlorophenyl ) amino]benzeneacetate (XX); trans - 3 - ( 4-hydroxy- 3 -methoxyphenyl ) - 2-propenoic acid-, 4- (nitrooxy) butyl ester (XXI); trans 3 - ( 4-hydroxy- 3 -methoxyphenyl ) - 2-propenoic acid-, 3- (nitrooxymethyl )phenyl ester (XXII); trans 3 - ( 4 -hydroxy- 3 -methoxyphenyl ) - 2-propenoic acid-, 6- (nitrooxymethyl) -2-pyridinylmethyl ester hydro- cloride (XXIII);

2-fluoro-alpha-methyl- [1 ,1' -biphenyl] -4 -acetic acid (nitrooxy butyl)ester (XXX);

(S) -N-acetylcysteine-4- (nitrooxy)butylester- , trans- 3 - ( -hydroxy- 3 -methoxypheny1 ) - 2-propenoate (XXIV) ; trans - 3 - ( 4-hydroxy- 3 -methoxyphenyl ) - 2 -propenoic acid- , 2 -methoxy- - [ (IE) -3- [4- (nitrooxy)butoxy] -3 -oxo-1- propenyl]phenylester (XXV).

10. Use according to claims 1-9, wherein if the compounds of formula (I) have one or more chiral centres, they are used in racemic form or as mixtures of diastereoisomers , as single enantiomers or single diastereoisomers; if they show geometric asymmetry, the compounds in the cis or trans form are used.

11. Use according to claims 1-10, wherein the compounds of formula (I) are used in combination with one or more vaccines .

12. Mixtures of compounds as defined in claim 11.

13. Compounds according to claim 9, selected from: trans 3 - ( 4 -hydroxy- 3 -methoxyphenyl ) - 2-propenoic acid-, 4- (nitrooxy)butyl ester (XXI); trans 3 - ( 4-hydroxy- 3 -methoxyphenyl ) - 2-propenoic acid-, 3- (nitrooxymethyl )phenyl ester (XXII); trans 3 - ( 4 -hydroxy- 3 -methoxyphenyl ) - 2-propenoic acid-, 6- (nitrooxymethyl ) -2-pyridinylmethyl ester hydro- cloride (XXIII);

(S) -N-acetylcysteine-4- (nitrooxy)butylester- , trans- 3 - ( 4 -hydroxy- 3 -methoxyphenyl ) - 2 -propenoate ( XXIV) ; trans - 3 - ( 4-hydroxy- 3 -methoxyphenyl ) - 2-propenoic acid- , 2 -methoxy- 4- [ ( IE) -3- [ 4- (nitrooxy)butoxy] - 3-oxo-1- propenyl]phenylester (XXV).