51079-99-3Relevant academic research and scientific papers
Redox Reactions of Dopamine Transients in Aqueous Solution: a Pulse Radiolysis Study
Maity, Dilip K.,Mohan, Hari,Mittal, Jai P.
, p. 919 - 924 (2007/10/02)
On reaction of e-eq with protonated dopamine (D) a transient optical absorption band max = 355 nm (ε = 5100 dm3 mol-1 cm-1)> has been assigned to an e-eq adduct of the dopamine ring (D-radical anion) (the first site of attack of e-eq), which subsequently goes to the amine site to cleave the C-N bond.The bimolecular rate constant for the reaction of e-eq with protonated dopamine has been determined to be 2.5*108 dm3 mol-1 s-1.The transient optical absorption band (λmax = 355 nm, ε = 3760 dm3 mol-1 cm-1) formed on reaction of H atoms with protonated dopamine has been assigned to a H-adduct of dopamine.The bimolecular rate constant for the reaction has been determined to be 4.2*108 dm3 mol-1 s-1 from the build up kinetics of the 355 nm band.The transient H-adduct decays with the formation of ammonia.The isopropanol radical is unable to undergo a one electron transfer reaction with dopamine, whereas an equilibrium is established between the benzamide radical anion and dopamine from which the redox potential for the D/D-radical anion couple has been determined to be -1.91 V.The dopamine radical anion (D-radical anion) is a strong reducing agent and is able to reduce methyl violegen with a bimolecular rate constant of 3.3*1010 dm3 mol-1 s-1.Specific one electron oxidants are able to undergo one electron transfer reactions forming a dopamine semiquinone radical (DSQ-radical) ( λmax = 290 nm, ε = 7750 dm3 mol-1 cm-1).
