Synthesis of dopamine and L-DOPA-alpha-glycosides by reaction with cyclomaltohexaose catalyzed by cyclomaltodextrin glucanyltransferase.
Dopamine-HCl and L-DOPA-alpha-glycosides were prepared by reaction with cyclomaltohexaose, catalyzed by Bacillus macerans cyclomaltodextrin glucanyltransferase. The reaction gave maltodextrins attached to dopamine and L-DOPA; the maltodextrins were trimmed by reactions with glucoamylase and beta-amylase to produce alpha-glucosyl- and alpha-maltosyl-glycosides, respectively. The glucoamylase- or beta-amylase-treated dopamine- and L-DOPA-alpha-glycosides were fractionated and purified by BioGel P-2 gel-filtration column chromatography and preparative descending paper chromatography. Analysis by MALDI-TOF mass spectrometry and one- and two-dimensional NMR showed that the purified glycosides of dopamine and L-DOPA were glycosylated at the hydroxyl groups of positions 3 and 4 of the catechol ring. The major product was found to be 4-O-alpha-glycopyranosyl L-DOPA, and it was shown to be more resistant to oxidative tolerance experiments, involving hydrogen peroxide and ferrous ion, than L-DOPA. L-DOPA-alpha-glycosides are possibly more effective substitutes for L-DOPA in treating Parkinson's disease in that they are more resistant to oxidation and methylation, which renders L-DOPA ineffective and deleterious.
Laboratory of Carbohydrate Chemistry and Enzymology, 4252 Molecular Biology Bldg., Iowa State University, Ames, IA 50011, USA.
Seung-Heon
SH
Yoon
D
D
Bruce Fulton
John F
JF
Robyt
D001407:Bacillus / Q000201:enzymology; D004298:Dopamine / Q000138:chemical synthesis* / Q000378:metabolism; D005964:Glucosyltransferases / Q000378:metabolism*; D006027:Glycosides / Q000138:chemical synthesis*; D007980:Levodopa / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D011134:Polysaccharides / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D006027:Glycosides; D011134:Polysaccharides; D007980:Levodopa; C008315:maltodextrin; D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase; D004298:Dopamine