Compound of formula I: ** Formula ** or a pharmaceutically acceptable salt, solvate or polymorph thereof, in which: R1 is selected from the group consisting of a linear or branched C1-C6 alkyl, a C2 alkenyl -C6 linear or branched, a linear or branched C2-C6 alkynyl, or heteroalkyl, a C3-C8 cycloalkyl, a C3-C8 cycloalkenyl, a heterocycloalkyl, an amine, an aryl and a heteroaryl, wherein said alkyl , alkenyl, alkynyl, heteroalkyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, aryl, amine or heteroaryl is unsubstituted or substituted with one or more Ra, wherein Ra is independently selected at each occurrence from the group consisting of: a) a linear or branched C1-C6 alkyl, b) a linear or branched C2-C6 alkenyl, c) a linear or branched C2-C6 alkynyl, d) a linear or branched, saturated or unsaturated C1-C6 haloalkyl, and ) a linear or branched, saturated or unsaturated C1-C6 alkoxy or aryloxy or, f) a linear or branched, saturated or unsaturated C1-C6 haloalkoxy, g) a linear or branched, saturated or unsaturated C1-C6-sulfonyl alkyl, h) a linear or branched, saturated C1-C6 thioalkyl or thioaryl or unsaturated, wherein said alkyl, alkenyl, alkynyl, and aryl in a) -h) is unsubstituted or independently substituted at each occurrence with one or more Rb, i) a C3-C8 cycloalkyl, wherein said cycloalkyl is unsubstituted or independently substituted at each occurrence with one or more Rb, j) a C3-C8 cycloalkenyl, wherein said cycloalkenyl is unsubstituted or independently substituted at each occurrence with one or more Rb, k) an aryl, in wherein said aryl is unsubstituted or independently substituted at each occurrence with one or more Rb, l) a heteroaryl, wherein said heteroaryl is unsubstituted or independently substituted at each occurrence with one or more Rb, m) a heterocycloalkyl, in which said heterocycloalk ilo is unsubstituted or independently substituted at each occurrence with one or more Rb, n) hydroxyl, o) cyano, p) amino, q) nitro, r) halogen, s) CORb, t) COORb, u
