A compound of formula I-0, and its pharmaceutically acceptable salt or salts and physiologically hydrolysable derivatives in free form or salt form: wherein Z1 is C1-C4 linear or branched alkyl or alkenyl R4 is selected from unsubstituted and substituted C3-C3 cycloalkyl, C1-C8 linear or branched alkyl, C2-5 alkenyl, C6-C10 heteroaryl or aryl, or C3-C8 heterocyclyl which may be part unsaturated, and combinations thereof Z is linear C2-3 alkylene X1 is selected from NH and O X2 is selected from unsaturated C and unsaturated S and X3 is selected from NH and CH2 or one of X1 and X3 is a single bond or X1 is O and X2 and X3 together are a single bond and R7 is selected from oxo, F, Cl, Br, CN, NH2, NR92, NO2, CF3, OR9, COR9, OCOR9, COOR9, NR9COR9, CONR92SO2NR92, NR9SO2R9 and R8 is selected from C1-5 alkyl, C1-5 alkoxyl, C2-5 alkenyl or alkynyl, C6-10 aryl and C3-8 cycloalkyl and combinations thereof, which may be unsubstituted or further substituted by one or more F, Cl, Br, CN, NH2, NR32, NO2, CF3 and R9 is selected from H and a group R8 as hereinbefore defined n7 and n8 and the sum thereof are independently selected from zero and the whole number integer 1 to 4 processes for the preparation thereof, compositions and uses.