56808-40-3

Upstream product

• 1263-76-9 maltotetraose 
• 2492-87-7 4-nitrophenyl-β-D-glucoside 
• 100-02-7 4-nitro-phenol 
• 127264-52-2 trideca-O-acetyl-α-maltotetraosyl bromide 

Downstream Products

• 198561-70-5 C₃₇H₄₉NO₂₃ 

Relevant academic research and scientific papers

Examination of the active sites of human salivary α-amylase (HSA)

The action pattern of human salivary amylase (HSA) was examined by utilising as model substrates 2-chloro-4-nitrophenyl (CNP) β-glycosides of maltooligosaccharides of dp 4-8 and some 4-nitrophenyl (NP) derivatives modified at the nonreducing end with a 4,6-O-benzylidene (Bnl) group. The product pattern and cleavage frequency were investigated by product analysis using HPLC. The results revealed that the binding region in HSA is longer than five subsites usually considered in the literature and suggested the presence of at least six subsites; four glycone binding sites (-4, -3, -2, -1) and two aglycone binding sites (+1, +2). In the ideal arrangement, the six subsites are filled by a glucosyl unit and the release of maltotetraose (G4) from the nonreducing end is dominant. The benzylidene group was also recognisable by subsites (-3) and (-4). The binding modes of the benzylidene derivatives indicated a favourable interaction between the Bnl group and subsite (-3) and an unfavourable one with subsite (-4). Thus, subsite (-4) must be more hydrophylic than hydrophobic. As compared with the action of porcine pancreatic α-amylase (PPA) on the same substrates, the results showed differences in the three-dimensional structure of active sites of HSA and PPA. (C) 2000 Elsevier Science Ltd.

Synthesis of chromogenic substrates of α-amylases on a cyclodextrin basis

One-pot acetylation and subsequent partial acetolysis of α-, β-and γ- cyclodextrins resulted in crystalline peracetylated malto-hexaose, -heptaose, and -octaose, respectively. Prolonged acetolysis of β-cyclodextrin gave a mixture of acetylated maltooligosaccharides, from which peracetylated malto- triose, -tetraose, and -pentaose were isolated. The acetylated oligosaccharides were converted into α-acetobromo derivatives, and then transformed into 4-nitrophenyl and 2-chloro-4-nitrophenyl β-glycosides. From the 4-nitrophenyl glycosides 4,6-O-benzylidene derivatives were prepared, which were used together with the free glycosides as substrates of porcine pancreatic α-amylase.

Transglycosylation reaction of maltotriose-forming amylase from Streptomyces griseus

A maltotriose-forming amylase from Streptomyces griseus produced predominantly p-nitrophenyl α-maltotetraoside through a transglycosylation reaction from maltotetraose as a donor and p-nitrophenyl α-D-glucopyranoside as an acceptor in an organic co-solven