69460-25-9

Upstream product

• 1263-76-9 Maltotetraose 
• 59-56-3 α-D-glucopyranosyl-1-phosphate 
• 528-50-7 cellobiose 
• 2106-10-7 1-deoxy-1-fluoro-α-D-glucose 

Downstream Products

• 71314-43-7 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl-[(1→4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl]₅-(1→4)-1,2,3,6-tetra-O-acetyl-α,β-D-glucopyranose 
• 345319-76-8 5-O-α-D-glucopyranosyl-(+)-catechin 
• 345319-75-7 (+)-catechin 7-α-O-glucoside 
• 67-47-0 5-hydroxymethyl-2-furfuraldehyde 
• 50-99-7 D-glucose 
• 99-20-7 TREHALOSE 
• 1668-09-3 maltopentaose 
• 172957-44-7 maltopentaosyltrehalose 
• 1263-76-9 maltotetraose 
• 5090-06-2 malto-nonaose 
• 1668-09-3 maltopentaose 

Relevant academic research and scientific papers

Characterization and mechanism of action of Microbacterium imperiale glucan 1,4-α-maltotriohydrolase

In this study, glucan 1,4-α-maltotriohydrolase (AMTS) from Microbacterium imperiale was purified and characterized. Hydrolysis by AMTS was affected by starch structure (e.g., amylose versus amylopectin) and hydrolysis time. During the initial phase of hydrolysis of maltooligosaccharides (G4-G7), AMTS displayed a unique transfer specificity to the transfer of maltotriosyl units. After extensive hydrolysis, maltotriose became the major end product, followed by glucose and maltose. Maltotetraose (G4) was the smallest donor in transglycosylation reactions by AMTS. This is the first study that reports transglycosylation activity of AMTS on maltooligosaccharides. The results of this study suggest that high purity maltotriose can be produced by the hydrolytic action of AMTS on starch.

Efficient chemoenzymatic oligosaccharide synthesis by reverse phosphorolysis using cellobiose phosphorylase and cellodextrin phosphorylase from Clostridium thermocellum

Inverting cellobiose phosphorylase (CtCBP) and cellodextrin phosphorylase (CtCDP) from Clostridium thermocellum ATCC27405 of glycoside hydrolase family 94 catalysed reverse phosphorolysis to produce cellobiose and cellodextrins in 57% and 48% yield from α-d-glucose 1-phosphate as donor with glucose and cellobiose as acceptor, respectively. Use of α-d-glucosyl 1-fluoride as donor increased product yields to 98% for CtCBP and 68% for CtCDP. CtCBP showed broad acceptor specificity forming β-glucosyl disaccharides with β-(1→4)- regioselectivity from five monosaccharides as well as branched β-glucosyl trisaccharides with β-(1→4)-regioselectivity from three (1→6)-linked disaccharides. CtCDP showed strict β-(1→4)-regioselectivity and catalysed linear chain extension of the three β-linked glucosyl disaccharides, cellobiose, sophorose, and laminaribiose, whereas 12 tested monosaccharides were not acceptors. Structure analysis by NMR and ESI-MS confirmed two β-glucosyl oligosaccharide product series to represent novel compounds, i.e. β-d-glucopyranosyl-[(1→4)- β-d-glucopyranosyl]n-(1→2)-d-glucopyranose, and β-d-glucopyranosyl-[(1→4)-β-d-glucopyranosyl]n- (1→3)-d-glucopyranose (n = 1-7). Multiple sequence alignment together with a modelled CtCBP structure, obtained using the crystal structure of Cellvibrio gilvus CBP in complex with glucose as a template, indicated differences in the subsite +1 region that elicit the distinct acceptor specificities of CtCBP and CtCDP. Thus Glu636 of CtCBP recognized the C1 hydroxyl of β-glucose at subsite +1, while in CtCDP the presence of Ala800 conferred more space, which allowed accommodation of C1 substituted disaccharide acceptors at the corresponding subsites +1 and +2. Furthermore, CtCBP has a short Glu496-Thr500 loop that permitted the C6 hydroxyl of glucose at subsite +1 to be exposed to solvent, whereas the corresponding longer loop Thr637-Lys648 in CtCDP blocks binding of C6-linked disaccharides as acceptors at subsite +1. High yields in chemoenzymatic synthesis, a novel regioselectivity, and novel oligosaccharides including products of CtCDP catalysed oligosaccharide oligomerisation using α-d-glucosyl 1-fluoride, all together contribute to the formation of an excellent basis for rational engineering of CBP and CDP to produce desired oligosaccharides.

Subsite Structure of Chalara paradoxa Glucoamylase and Interaction of the Glucoamylase with Cyclodextrins

The action of Chalara paradoxa glucoamylase (raw-starch-digesting enzyme) was studied with linear and cyclic maltodextrins.Subsite affinities (Ai) of the amylase were evaluated by the subsite theory.The active site was considered to be made up of seven subsites: A1 = 0.05 kcal/mol, A2 = 4.99 kcal/mol, A3 = 1.30 kcal/mol, A4 = 0.77 kcal/mol, A5 = 0.33 kcal/mol, A6 = 0.21 kcal/mol and A7 = 0.21 kcal/mol.Inhibitions by alpha-, beta-, and gamma-cyclodextrins were competitive for starch digestion by C. paradoxa glucoamylase.The inhibitor constants (Ki) of α-, β-, and γ-cyclodextrin for the amylase were 8.9, 1.4, and 3.9 mM, respectively.The Michaelis constant (Km) of 6-O-α-maltosyl-α-cyclodextrin digestion was 0.79 mM for the amylase.

POLYSACCHARIDES OF Eremurus. XV. STRUCTURE OF THE GLUCOMANNAN OF Eremurus lactiflorus.

Ten oligosaccharides have been isolated from the products of the partial hydrolysis of a native acetylated glucomannan obtained from Eremurus lactiflorus O.Fedtsch.Their structures have been studied with the aid of acid hydrolysis before and after reduction with NaBH4, by the GLC method, and also by chromatography with markers.The compositions and sequence of the monomers in tetra- and heptaoligosaccharides have been determined by the 13C NMR method.The glucomannan from the E. lactiflorus differs from the Eremurus glucomanans studied previously by the ratio of monosaccharides, the presence of O-Ac groups, the degree of polymerization, and the presence of a cellobiose unit (Glcp-Glcp) in the polymer chain.The repeating unit consists of 14 hexose residues.