title: Chemoenzymatic synthesis of 2-chloro-4-nitrophenyl beta-maltoheptaoside acceptor-products using glycogen phosphorylase b.
abstract: In the present work, we aimed at developing a chemoenzymatic procedure for the synthesis of beta-maltooligosaccharide glycosides. The primer in the enzymatic reaction was 2-chloro-4-nitrophenyl beta-maltoheptaoside (G(7)-CNP), synthesised from beta-cyclodextrin using a convenient chemical method. CNP-maltooligosaccharides of longer chain length, in the range of DP 8-11, were obtained by a transglycosylation reaction using alpha-D-glucopyranosyl-phosphate (G-1-P) as a donor. Detailed enzymological studies revealed that the conversion of G(7)-CNP catalysed by rabbit skeletal muscle glycogen phosphorylase b (EC 2.4.1.1) could be controlled by acarbose and was highly dependent on the conditions of transglycosylation. More than 90% conversion of G(7)-CNP was achieved through a 10:1 donor-acceptor ratio. Tranglycosylation at 37 degrees C for 30 min with 10 U enzyme resulted in G(8-->12)-CNP oligomers in the ratio of 22.8, 26.6, 23.2, 16.5, and 6.8%, respectively. The reaction pattern was investigated using an HPLC system. The preparative scale isolation of G(8-->11)-CNP glycosides was achieved on a semipreparative HPLC column. The productivity of the synthesis was improved by yields up to 70-75%. The structures of the oligomers were confirmed by their chromatographic behaviours and MALDI-TOF MS data.
authors.affiliation: Department of Biochemistry, University of Debrecen, PO Box 55, H-4010 Debrecen, Hungary. kandra@tigris.klte.hu
authors.forename: L
authors.initials: L
authors.lastname: Kandra
authors.forename: G
authors.initials: G
authors.lastname: Gyémánt
authors.forename: M
authors.initials: M
authors.lastname: Pál
authors.forename: M
authors.initials: M
authors.lastname: Petró
authors.forename: J
authors.initials: J
authors.lastname: Remenyik
authors.forename: A
authors.initials: A
authors.lastname: Lipták
mesh_terms: D020909:Acarbose / Q000737:chemistry; D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000737:chemistry; D005960:Glucosides / Q000138:chemical synthesis* / Q000737:chemistry; D024981:Glycogen Phosphorylase / Q000737:chemistry / Q000378:metabolism*; D006027:Glycosides / Q000138:chemical synthesis* / Q000737:chemistry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D011817:Rabbits; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D005960:Glucosides; D006027:Glycosides; D009844:Oligosaccharides; C021705:maltooligosaccharides; C042976:2-chloro-4-nitrophenyl maltoheptaoside; D024981:Glycogen Phosphorylase; D020909:Acarbose