Chemical synthesis of 6"'-alpha-maltotriosyl-maltohexaose as substrate for enzymes in starch biosynthesis and degradation.
A branched nonasaccharide 6"'-alpha-maltotriosyl-maltohexaose was synthesised in 40 steps from D-glucose and maltose. Phenyl O-(2,3,4,6-tetra-O-benzyl-alpha-D-glucopyranosyl)-(1-->4)-O- (2,3,6-tri-O-benzyl-alpha-D-glucopyranosyl)-(1-->4)-2,3-di-O-benzyl-1-th io- beta-D-glucopyranoside and O-(2,3,4,6-tetra-O-benzyl-alpha-D-glucopyranosyl)-(1-->4)-O-(2,3,6-tri- O-benzyl-alpha-D-glucopyranosyl)-(1-->4)-2,3,6-tri-O-benzyl-alpha, beta-D-glucopyranosyl trichloroacetimidate were coupled by a general condensation reaction to form the per-O-benzylated branched hexasaccharide phenyl thioglycoside. The phenylthio group of this compound was converted into a trichloroacetimidate, which was coupled with phenyl O-(2,3,6-tri-O-benzyl-alpha-D-glucopyranosyl)-(1-->4)-O-(2,3,6-tri-O- benzyl-alpha-D-glucopyranosyl)-(1-->4)-2,3,6-tri-O-benzyl-1-thio-beta-D- glucopyranoside to afford the per-O-benzylated branched nonasaccharide phenyl thioglycoside. Replacement of the phenylthio group with a free OH-group followed by hydrogenolysis gave the desired product. The synthons reported for this synthesis constitute a versatile tool for the chemical synthesis of other complex carbohydrates.
Damager
I
I
Department of Plant Biology, Royal Veterinary and Agricultural University, Copenhagen, Denmark.
Olsen
C E
CE
Møller
B L
BL
Motawia
M S
MS
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005947:Glucose; D007202:Indicators and Reagents; D008320:Maltose; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D009904:Optical Rotation; D013213:Starch / Q000096:biosynthesis / Q000378:metabolism*; D013379:Substrate Specificity
C400079:6'''-alpha-maltotriosyl-maltohexaose; D007202:Indicators and Reagents; D009844:Oligosaccharides; D008320:Maltose; D013213:Starch; D005947:Glucose