Cyclodextrin cycloheptaamylose

These water-soluble molecules are cyclic oligomers of a-D-glucose formed by the action of certain bacterial amylases on starches (Bender and Komiyama, 1978 Saenger, 1980 Szejtli, 1982). a-Cyclodextrin (cyclohexa-amylose) has six glucose units joined a(l, 4) in a torus [1], whereas /3-cyclodextrin (cycloheptaamylose) and y-cyclodextrin (cyclooctaamylose) have seven and eight units, respectively. 

In the full study [64], it was found that a lesser but similar effect was seen with j8-cyclodextrin (cycloheptaamylose), which has a larger cavity in which anisole is both more weakly and more flexibly bound. Within this looser complex, ortho chlorination is... 

Synonyms Alphadex Betadex Cycloamylase a-Cyclodextrin p Cyclo-dextrin y-Cyclodextrin Cycloheptaamylose Cycloheptaglucosan Cyclomaltoheptaose Cyclomaltohexaose Cyclomaltooctaose Schardinger a-dextrin... 

In relation to separation of nucleotides, Hoffman61 found that adenine nucleotides interacted most strongly with cycloheptaamylose, presumably by inclusion of the base within the cavity of cyclodextrin. When epichlorohydrin-cross-linked cycloheptaamylose gel was used as a stationary phase for nucleic acid chromatography, adenine-containing compounds were retarded most strongly. 

Unsubstituted cycloamyloses have been used to catalyze a number of reactions in addition to acyl group transfer. Brass and Bender (8) showed that cycloamyloses promoted phenol release from diphenyl and bis(p-nitro-phenyl) carbonates and from diphenyl and bis(m-nitrophenyl)methyl phos-phonates. Breslow and Campbell (10,11) showed that the reaction of anisole with HOCL in aqueous solution is catalyzed by cyclohexaamylose and cycloheptaamylose. Anisole is bound by the cyclodextrins and is chlorinated exclusively in the para position while bound. Cycloheptaamylose has been used to promote regiospecific alkylation followed by the highly selective oxidation shown in reaction (3) (95). In addition cycloheptaamylose effec-... 

Lindner, K. Saenger, W. Topography of cyclodextrin complexes. Part XVII. Crystal and molecular structure of cycloheptaamylose dodecahydrate. Carbohydr. Res. 1982, 99(2), 103-115. 

P-Cyclodextrin beta-cycloamylose beta-dextrin Cavamax W7 Pharma cycloheptaamylose cycloheptaglucan cyclo-maltoheptose Kleptose. 

Much more successful has been the tailor-making of catalysts combining cyclodextrins with transition metals or other heavy elements with multiple valencies. The cyclodextrins envelope labile catalytic centres and/or provide a binding site. Enzyme mimicry is more plausible where the specialist chemistry of a cofactor is crucial. Thus, a 2 2 -ditelluro-bis-cycloheptaamylose in its oxidised form had a kcmlKm for oxidation of 3-carboxy-4-nitrobenzenethiol only 600-fold less than that of glutathione peroxidase oxidising glutathione -but even here the mimicry is not close, as the enzyme uses a selenium, not a tellurium, cofactor. 

Gunaratne, A and H Corke (2007). Influence of unmodified and modified cycloheptaamylose (/8-cyclodextrin) on transition parameters of amylose-lipid complex and functional properties of starch. Carbohydrate Polymer, 68,226-234. 

Cyclo-1,13-ethylenedioxytridecan-1,13-dione Cyclo-1,13-ethylenedioxytridecane-1,13-dione. See Ethylene brassylate Cyciogaibanate 3/024061. See Acetic acid, (cyclohexyloxy)-, 2-propenyl ester Cycloheptaamylose. See 3-Cyclodextrin Cyclodextrin... 

Cycloheptakis-( 1 - 4)-(a-D-glticopyra-nose). Cycloheptaamylose. Cyclomaltohep-taose. Betadex, BAN, INN, USAN. Beta cyclodextrin, USAN. Cycloheptaglucan. Cycloheptamaltose. fi-Schardinger dextran. E459... 

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