A study on the electrochemical synthesis of L-DOPA using oxidoreductase enzymes: optimization of an electrochemical process.
Levodopa or L-3,4-dihydroxyphenylalanine (L-DOPA) is the precursor of the neurotransmitter dopamine. L-DOPA is a famous treatment for Parkinson's disease symptoms. In this study, electroenzymatic synthesis of L-DOPA was performed in a three-electrode cell, comprising a Ag/AgCl reference electrode, a platinum wire auxiliary electrode, and a glassy carbon working electrode. L-DOPA had an oxidation peak at 376 mV and a reduction peak at -550 mV. The optimum conditions of pH, temperature, and amount of free tyrosinase enzyme were pH 7, 30 degrees C, and 250 IU, respectively. The kinetic constant of the free tyrosinase enzyme was found for both cresolase and catacholase activity to be 0.25 and 0.4 mM, respectively. A cyclic voltammogram was used to investigate the electron transfer rate constant. The mean heterogeneous electron transfer rate (ke) was 5.8 × 10(-4) cm/s. The results suggest that the electroenzymatic method could be an alternative way to produce L-DOPA without the use of a reducing agent such as ascorbic acid.
Interdisciplinary Program of Bioenergy and Biomaterial Engineering, Chonnam National University, Gwangju 500-757, Korea.
Siti Fauziyah
SF
Rahman
Sriramulu
S
Gobikrishnan
Natarianto
N
Indrawan
Seok-Hwan
SH
Park
Jae-Hee
JH
Park
Kyoungseon
K
Min
Young Je
YJ
Yoo
Don-Hee
DH
Park
D016227:Benzoquinones / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D004579:Electron Transport; D004583:Electrons; D004789:Enzyme Activation; D057075:Enzyme Assays / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007980:Levodopa / Q000138:chemical synthesis* / Q000737:chemistry; D014442:Monophenol Monooxygenase / Q000737:chemistry; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D018030:Silver Compounds / Q000737:chemistry
D016227:Benzoquinones; D018030:Silver Compounds; D012834:Silver; D007980:Levodopa; D010984:Platinum; D004295:Dihydroxyphenylalanine; D002244:Carbon; C035157:dopaquinone; D014442:Monophenol Monooxygenase; C037548:silver chloride