3-O-methyl-L-DOPA is a metabolite of L-DOPA , produced by the activity of catechol O-methyltransferase. 3-O-methyl-L-DOPA may have effects of its own or it may compete with the actions of L-DOPA.
Etilevodopa is an ethyl-ester prodrug of Levodopa which is used for the treatment of Parkinson's disease (PD). It is rapidly hydrolyzed to Levodopa and ethanol by nonspecific esterases in the gastrointestinal tract. Levodopa is the direct precursor of dop
D-DOPA is an enantiomer of the dopamine precursor L-DOPA . It can be converted to L-DOPAviasequential oxidation and transamination, which are mediated by D-amino acid oxidase (DAAO) and DOPA transaminase, respectively, in rat kidney homogenates.1It reduces the number of dopaminergic neurons in primary rat embryonic mesencephalic cultures in a concentration-dependent manner.2Intraventricular administration of D-DOPA (200 μg/animal) increases striatal dopamine levels in rats.3D-DOPA (20 mg/kg, i.p.) induces contralateral turns in a rat model of Parkinson's disease induced by 6-OHDA .4 1.Wu, M., Zhou, X.-J., Konno, R., et al.D-dopa is unidirectionally converted to L-dopa by D-amino acid oxidase, followed by dopa transaminaseClin. Exp. Pharmacol. Physiol.33(11)1042-1046(2006) 2.Ling, Z.-D., Pieri, S.C., and Carvey, P.M.Comparison of the neurotoxicity of dihydroxyphenylalanine stereoisomers in cultured dopamine neuronsClin. Neuropharmacol.19(4)360-365(1996) 3.Karoum, F., Freed, W.J., Chuang, L.-W., et al.D-dopa and L-dopa similarly elevate brain dopamine and produce turning behavior in ratsBrain Res.440(1)190-194(1988) 4.Moses, J., Siddiqui, A., and Silverman, P.B.Sodium benzoate differentially blocks circling induced by D-and L-dopa in the hemi-parkinsonian ratNeurosci. Lett.218(3)145-148(1996)
SD-1077, also known as d3-L-DOPA, is a deuterium containing levodopa. SD-1077 has been shown in preclinical models to improve the half-life of dopamine in the brain resulting in a prolonged treatment effect.