The present invention relates to a compound of formula (I), or apharmaceutically acceptable salt thereof, wherein Z is OR1 or NR1R2 whereineach of R1 and R2 is independently H, or a hydrocarbyl group； X is analkylene, alkenylene, or alkynylene group, each of which may be optionallysubstituted by one or more substituents selected from alkyl, COOH, CO2-alkyl,alkenyl, CN, NH2, hydroxy, halo, alkoxy, CF3 and nitro； Y is a polarfunctional group selected from OH, NO2, CN, COR3, COOR3, NR3R4, CONR3R4, SO3H,SO2-R3, SO2NR3R4 and CF3, where each of R3 and R4 is independently H or ahydrocarbyl group； A is an aryl or heteroaryl group, each of which may beoptionally substituted； and B is (CH2)n where n is 0, 1, 2, 3, 4 or 5； withthe proviso that: (i) when A is phenyl, n is 0, and Z is OH, X-Y is other thanmeta-C.ident.-C-(CH2)2CO2H, meta-C.ident.-C-(CH2)2OH, meta-C.ident.C-(CH2)2CO2Me, meta-(CH2)4CO2H, ortho-CH2CO2H, ortho-(CH2)2CO2Hand ortho-(CH2)4CO2H； and (ii) when A is phenyl, n is 0, and Z is OMe, X-Y is other thanmeta-C.ident.C-(CH2)4OH. Further aspects of the invention relate to the use ofsuch compounds in the preparation of a medicament for the treatment of amuscular disorder, a gastrointestinal disorder, or for controlling spasticityor tremors.
