<unk>  ('-3,4-dihydroxyphenylalanine; dextrodopa) is similar to<unk>  (levodopa), but with opposite chirality. Levo- and dextro- rotation refer to a molecule's ability to rotate planes of polarized light in one or the other direction. Whereas<unk>  is moderately effective in the treatment of Parkinson's disease (PD) and<unk> mine-responsive dystonia (DRD) by stimulating the production of<unk> mine in the brain,<unk>  is biologically inactive.
D-DOPA
L-DOPA
4-Methylaminorex
Phenserine
Glutamate 
Nicotinamide
Beta-Hydroxy beta-methylbutyric acid
Gamma-Hydroxybutyric acid