title: Enzymatic synthesis of L-DOPA alpha-glycosides by reaction with sucrose catalyzed by four different glucansucrases from four strains of Leuconostoc mesenteroides.
abstract: L-DOPA alpha-glycosides were synthesized by reaction of L-DOPA with sucrose, catalyzed by four different glucansucrases from Leuconostoc mesenteroides B-512FMC, B-742CB, B-1299A, and B-1355C. The glucansucrases catalyzed the transfer of d-glucose from sucrose to the phenolic hydroxyl position-3 and -4 of L-DOPA. The glycosides were fractionated and purified by Bio-Gel P-2 column chromatography, and the structures were determined by (1)H NMR spectroscopy. The major glycoside was 4-O-alpha-d-glucopyranosyl L-DOPA, and the minor glycoside was 3-O-alpha-D-glucopyranosyl L-DOPA. The two glycosides were formed by all four of the glucansucrases. The ratio of the 4-O-alpha-glycoside to the 3-O-alpha-glycoside produced by the B-512FMC dextransucrase was higher than that for the other three glucansucrases. The glycosylation of L-DOPA significantly reduced the oxidation of the phenolic hydroxyl groups, which prevents their methylation, potentially increasing the use of L-DOPA in the treatment of Parkinson's disease. The use of one enzyme, glucansucrase, and sucrose as the D-glucosyl donor makes the synthesis considerably simpler and cheaper than the formerly published procedure using cyclomaltodextrin and cyclomaltodextrin glucanyltransferase, followed by glucoamylase, and beta-amylase hydrolysis.
authors.affiliation: Laboratory of Carbohydrate Chemistry and Enzymology, Iowa State University, Ames, IA 50011, USA.
authors.forename: Seung-Heon
authors.initials: SH
authors.lastname: Yoon
authors.forename: D Bruce
authors.initials: DB
authors.lastname: Fulton
authors.forename: John F
authors.initials: JF
authors.lastname: Robyt
mesh_terms: D055162:Biocatalysis; D006027:Glycosides / Q000096:biosynthesis* / Q000378:metabolism; D006031:Glycosylation; D016695:Glycosyltransferases / Q000737:chemistry / Q000378:metabolism*; D007934:Leuconostoc / Q000201:enzymology*; D007980:Levodopa / Q000096:biosynthesis* / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism*
chemical_list: D006027:Glycosides; D007980:Levodopa; D013395:Sucrose; D016695:Glycosyltransferases; C033837:alternansucrase