The present invention describes a series of therapeutically active compounds of formula I,X—Y—Z (I)that are useful for treating a disorder in a
mammal. In the formula I, X and Z, which may be same or different, are independently selected from substituted or unsubstituted
alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkylalkyl, substituted or unsubstituted
aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted heterocyclic group or substituted or unsubstituted heterocyclylalkyl; and Y is a
linker selected from —O—, —S—, —NH—, —(CH2)n—, —CO—, —CONRa—, —NRaCO—, —NRaCOO—, —COO—, —CONRaCO—, —CONRaCOO— and —COOCOO—. The compounds are useful to treat neurodegenerative disorders, depression, Alzheimer's
disease, cognitive disorders, motor disorders, Parkinson's
disease,
drug addiction, behavioral disorders, inflammatory disorders,
stomach disorders, cancers,
acute pain,
chronic pain and recurrent pain.