d-cysteine ethyl ester

D-cysteine ethyl ester is a **cell-permeant derivative of D-cysteine**, classified as a D-thiol ester. It exhibits enhanced ability to enter cells and neurons compared to D-cysteine itself. Preclinically, intravenous D-cysteine ethyl ester rapidly and persistently reverses the adverse effects of opioid drugs such as morphine and fentanyl on ventilatory parameters, arterial blood gases, and gas exchange in unrestrained rats, without affecting the analgesic or sedative properties of the opioids[1][3][6][8]. Unlike L-cysteine ethyl ester, D-cysteine ethyl ester does not appear to enter canonical metabolic pathways, potentially reducing side effects. Mechanistically, its pharmacological actions are likely related to its redox-modulating properties, altering intracellular signaling by impacting pathways relevant to opioid physical dependence and withdrawal—possibly involving glutamatergic signaling (notably NMDA receptors) and nitric oxide synthase-mediated S-nitrosylation/glutathionylation of cysteine residues on proteins[6]. D-cysteine ethyl ester is also studied for its antioxidant, neuroprotective, and biochemical research uses[7].

Other names

ethyl D-cysteinateH-D-Cys-OEtD-cysteine ethyl est