alpha-cyclodextrin and maltodextrin

Stochastic sensing was employed for pattern recognition of HER-1 in biological fluids. Nanostructured materials such as 5,10,15,20-tetraphenyl-21H,23H-porphyrin, maltodextrin and α-cyclodextrin were used to modify diamond paste for stochastic sensing of HER-1. Pattern recognition of HER-1 in biological fluids was performed in a linear concentration range between 5.60 × 10(-11) and 9.72 × 10(-7 )mg ml(-1). The lower limits of determination (10(-12 )mg ml(-1) magnitude order) were recorded when maltodextrin and α-cyclodextrin were used for stochastic sensing. The pattern recognition test of HER-1 in biological fluids samples shows high reliability for both qualitative and quantitative assay.

Topics: alpha-Cyclodextrins; Ascitic Fluid; Biomarkers, Tumor; Biosensing Techniques; ErbB Receptors; Humans; Nanostructures; Pattern Recognition, Automated; Polysaccharides; Porphyrins; Stochastic Processes

Novel 2-(β-maltooligooxy)-ethyl (meth)acrylate monomers are successfully synthesized by CGTase from Bacillus macerans catalyzed coupling of 2-(β-glucosyloxy)-ethyl acrylate and methacrylate with α-cyclodextrin or starch. HPLC-UV analysis shows that the CGTase catalyzed reaction yields 2-(β-maltooligooxy)-ethyl acrylates with 1 to 15 glucopyranosyl units. (1) H NMR spectroscopy reveals that the β-linkage in the acceptor molecule is preserved during the CGTase catalyzed coupling reaction, whereas the newly introduced glucose units are attached by α-(1,4)-glycosidic linkages. The synthesized 2-(β-maltooligooxy)-ethyl acrylate monomers are successfully polymerized by aqueous free radical polymerization to yield the comb-shaped glycopolymer poly(2-(β-maltooligooxy)-ethyl acrylate).

Topics: Acrylates; alpha-Cyclodextrins; Bacillus; Bacterial Proteins; Catalysis; Glucosyltransferases; Polysaccharides; Starch

The crystal structures of Thermoactinomyces vulgaris cyclo/maltodextrin-binding protein (TvuCMBP) complexed with alpha-cyclodextrin (alpha-CD), beta-cyclodextrin (beta-CD) and maltotetraose (G4) have been determined. A common functional conformational change among all solute-binding proteins involves switching from an open form to a closed form, which facilitates transporter binding. Escherichia coli maltodextrin-binding protein (EcoMBP), which is structurally homologous to TvuCMBP, has been determined to adopt the open form when complexed with beta-CD and the closed form when bound to G4. Here, we show that, unlike EcoMBP, TvuCMBP-alpha-CD and TvuCMBP-beta-CD adopt the closed form when complexed, whereas TvuCMBP-G4 adopts the open form. Only two glucose residues are evident in the TvuCMBP-G4 structure, and these bind to the C-domain of TvuCMBP in a manner similar to the way in which maltose binds to the C-domain of EcoMBP. The superposition of TvuCMBP-alpha-CD, TvuCMBP-beta-CD and TvuCMBP-gamma-CD shows that the positions and the orientations of three glucose residues in the cyclodextrin molecules overlay remarkably well. In addition, most of the amino acid residues interacting with these three glucose residues also participate in interactions with the two glucose residues in TvuCMBP-G4, regardless of whether the protein is in the closed or open form. Our results suggest that the mechanisms by which TvuCMBP changes from the open to the closed conformation and maintains the closed form appear to be different from those of EcoMBP, despite the fact that the amino acid residues responsible for the initial binding of the ligands are well conserved between TvuCMBP and EcoMBP.

Topics: alpha-Cyclodextrins; Amino Acid Sequence; Bacterial Proteins; beta-Cyclodextrins; Binding Sites; Crystallography, X-Ray; Micromonosporaceae; Models, Molecular; Multiprotein Complexes; Polysaccharides; Protein Binding; Protein Conformation; Protein Structure, Tertiary

Powdery encapsulation of shiitake flavors, extracted from dried shiitake, was investigated by spray drying. Flavor retention increased with an increase in drying air temperature and solid content, and decreased with an increase in dextrose equivalents of maltodextrin. A heat-treatment of the extract liquid made the lenthionine concentration increase, but did not influence the concentrations of the other flavors. The formation of lenthionine with heat-treatment could be described by the consecutive unimolecular-type first order reaction. Lenthionine content in a spray-dried powder prepared with the heated extracted liquid significantly increased. alpha-Cyclodextrin was the most suitable encapsulant of alpha-, beta-, and gamma-cyclodextrins to prepare the spray-dried powder, including lenthionine. The flavor retentions were markedly increased by using of alpha-cyclodextrin and maltodextrin in combination as an encapsulant.

Topics: alpha-Cyclodextrins; beta-Cyclodextrins; Capsules; Cyclodextrins; Food Technology; gamma-Cyclodextrins; Hot Temperature; Polysaccharides; Powders; Shiitake Mushrooms; Taste; Temperature; Thiepins

The taste and flavor of spray-dried powdered products are the most important quality factors. In the present study, molecular encapsulation in cyclodextrin was applied to prevent the loss of a hydrophobic flavor compound (l-menthol) during the drying of a droplet. beta-Cyclodextrin appeared to be a better encapsulant for menthol than alpha- and gamma-cyclodextrin. The retention of menthol increased with increasing concentration of both cyclodextrin and maltodextrin. A simple mathematical model is proposed for estimating the flavor retention. The theoretical results by this model estimated well the final retention of menthol encapsulated in a blend of beta-cyclodextrin and maltodextrin.

Topics: alpha-Cyclodextrins; beta-Cyclodextrins; Cyclodextrins; Drug Compounding; Freeze Drying; gamma-Cyclodextrins; Menthol; Models, Chemical; Polysaccharides; Taste