| abstract |
The present invention provides a selective M4 receptor antagonist, levorotatory demethylated phencynonate or its nontoxic pharmaceutically acceptable salt, a pharmaceutical composition comprising this compound, and a use thereof in the manufacture of a medicament for the treatment of motion dysfunction, such as, tremor, rigor and the like caused by Parkinson's disease (PD). The structure, of the compound is shown in Formula IIa: |