Compounds of the general formula: wherein: - R 1 is selected among • a cyclic pentose group in the furan form with the free OH groups or optionally substituted by one or several mono-, bi- or tri-phosphate group(s), acetyl group(s), isopropylidene group(s), benzoyl group(s) or para-toluoyle group(s), • a hexose group in the pyran form with the free OH groups or optionally substituted by one or several mono-, bi- or tri-phosphate group(s) or acetyl group(s), • a naphthyl group, optionally substituted by one or several substituted alkyl or amino group(s) having from 1 to 4 carbon atom(s), • a benzyl group, optionally substituted by one or several substituted alkyl or amino group(s) having from 1 to 4 carbon atom(s), • phenyl, biphenyl, heteroaryl groups; - R 2 is selected among • an amide group -CONH 2, -CONHMe, -CONHEt, -CON(Me) 2,-CON(Et) 2, • an acid or ester group -CO 2 H, CO 2 Me, CO 2 Et, a cyano or amidine group -CN, -C(NH 2)NH, -C(NHMe)NH, -C(NHEt)NH, • a phenyl group optionally substituted by a halogen selected among Cl, Br, I an F, • a thiophene group, • a straight or branched carbon chain having from 3 to 10 carbon atoms, or • a methoxynaphthalene group; and - R 3 is selected among • a halogen group, • a furan or -CO-furan group, • a thiophene or -CO-thiophene or -C=C-thiophene group, • a toluoyl group, • an acetylene group, • a -CO-(CH 2) n -CH 3 group, wherein n is comprised between 2 and 9, • a phenyl or -C≡C-phenyl group, optionally substituted by a halogen, • a -C≡C-CO 2 Me, -C≡C-CO 2 Et, -C≡C-CONH 2 group, • a -C≡C-(CH 2) 6 CH 3 group, or • a -C≡C-2-methoxynaphthalene group; their racemates, enantiomers, diastereoisomers and mixtures thereof, their tautomers and pharmaceutically acceptable salts thereof, for their use as a medicine. - R 1 is selected among • a cyclic pentose group in the furan form with the free OH groups or optionally substituted by one or several mono-, bi- or tri-phosphate group(s), acetyl group(s), isopropylidene group(s), benzoyl group(s) or para-toluoyle group(s), • a hexose group in the pyran form with the free OH groups or optionally substituted by one or several mono-, bi- or tri-phosphate group(s) or acetyl group(s), • a naphthyl group, optionally substituted by one or several substituted alkyl or amino group(s) having from 1 to 4 carbon atom(s), • a benzyl group, optionally substituted by one or several substituted alkyl or amino group(s) having from 1 to 4 carbon atom(s), • phenyl, biphenyl, heteroaryl groups; • a cyclic pentose group in the furan form with the free OH groups or optionally substituted by one or several mono-, bi- or tri-phosphate group(s), acetyl group(s), isopropylidene group(s), benzoyl group(s) or para-toluoyle group(s), • a hexose group in the pyran form with the free OH groups or optionally substituted by one or several mono-, bi- or tri-phosphate group(s) or acetyl group(s), • a naphthyl group, optionally substituted by one or several substituted alkyl or amino group(s) having from 1 to 4 carbon atom(s), • a benzyl group, optionally substituted by one or several substituted alkyl or amino group(s) having from 1 to 4 carbon atom(s), • phenyl, biphenyl, heteroaryl groups; - R 2 is selected among • an amide group -CONH 2, -CONHMe, -CONHEt, -CON(Me) 2,-CON(Et) 2, • an acid or ester group -CO 2 H, CO 2 Me, CO 2 Et, a cyano or amidine group -CN, -C(NH 2)NH, -C(NHMe)NH, -C(NHEt)NH, • a phenyl group optionally substituted by a halogen selected among Cl, Br, I an F, • a thiophene group, • a straight or branched carbon chain having from 3 to 10 carbon atoms, or • a methoxynaphthalene group; and • an amide group -CONH 2, -CONHMe, -CONHEt, -CON(Me) 2,-CON(Et) 2, • an acid or ester group -CO 2 H, CO 2 Me, CO 2 Et, a cyano or amidine group -CN, -C(NH 2)NH, -C(NHMe)NH, -C(NHEt)NH, • a phenyl group optionally substituted by a halogen selected among Cl, Br, I an F, • a thiophene group, • a straight or branched carbon chain having from 3 to 10 carbon atoms, or • a methoxynaphthalene group; and - R 3 is selected among • a halogen group, • a furan or -CO-furan group, • a thiophene or -CO-thiophene or -C=C-thiophene group, • a toluoyl group, • an acetylene group, • a -CO-(CH 2) n -CH 3 group, wherein n is comprised between 2 and 9, • a phenyl or -C≡C-phenyl group, optionally substituted by a halogen, • a -C≡C-CO 2 Me, -C≡C-CO 2 Et, -C≡C-CONH 2 group, • a -C≡C-(CH 2) 6 CH 3 group, or • a -C≡C-2-methoxynaphthalene group; • a halogen group, • a furan or -CO-furan group, • a thiophene or -CO-thiophene or -C=C-thiophene group, • a toluoyl group, • an acetylene group, • a -CO-(CH 2) n -CH 3 group, wherein n is comprised between 2 and 9, • a phenyl or -C≡C-phenyl group, optionally substituted by a halogen, • a -C≡C-CO 2 Me, -C≡C-CO 2 Et, -C≡C-CONH 2 group, • a -C≡C-(CH 2) 6 CH 3 group, or • a -C≡C-2-methoxynaphthalene group;