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. One-pot acetylation and subsequent partial acetolysis of cyclodextrins resulted in the peracetylated maltooligomers (dp 3–8), which were transformed into 4-nitrophenyl and 2-chloro-4-nitrophenyl β-glycosides, the 4.6-O-benzylidene derivatives of NP-glycosides were also prepared