6-o-maltosyl-beta-cyclodextrin and betadex

We investigate the formation mechanism of supramolecular complexes of four antioxidant oligopeptides (YW, WY, WYS, and WYSL) with β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) and 6-O-α-maltosyl-β-cyclodextrin (M-β-CD) by combined computational and experimental methods. The formation of complexes is determined by UV, IR and DSC, and the rank-ordered acquired stability of the complexes is as follows: WYSL/HP-β-CD > WYS/HP-β-CD > WY/HP-β-CD > YW/M-β-CD > YW/HP-β-CD > YW/β-CD. The

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Antioxidants; beta-Cyclodextrins; Calorimetry, Differential Scanning; Hydrophobic and Hydrophilic Interactions; Magnetic Resonance Spectroscopy; Molecular Docking Simulation; Oligopeptides; Solubility; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet

A gene encoding a putative glycogen-debranching enzyme in Sulfolobus shibatae (abbreviated as SSGDE) was cloned and expressed in Escherichia coli. The recombinant enzyme was purified to homogeneity by heat treatment and Ni-NTA affinity chromatography. The recombinant SSGDE was extremely thermostable, with an optimal temperature at 85 degrees C. The enzyme had an optimum pH of 5.5 and was highly stable from pH 4.5 to 6.5. The substrate specificity of SSGDE suggested that it possesses characteristics of both amylo-1,6-glucosidase and alpha-1,4-glucanotransferase. SSGDE clearly hydrolyzed pullulan to maltotrlose, and 6-O-alpha-maltosyl-beta-cyclodextrin (G2-beta-CD) to maltose and beta-cyclodextrin. At the same time, SSGDE transferred maltooligosyl residues to the maltooligosaccharides employed, and maltosyl residues to G2-beta-CD. The enzyme preferentially hydrolyzed amylopectin, followed in a decreasing order by glycogen, pullulan, and amylose. Therefore, the present results suggest that the glycogen-debranching enzyme from S. shibatae may have industrial application for the efficient debranching and modification of starch to dextrins at a high temperature.

Topics: Amylopectin; Amylose; beta-Cyclodextrins; Chemical Fractionation; Chromatography, Affinity; Cloning, Molecular; Enzyme Stability; Escherichia coli; Gene Expression; Glucans; Glycogen; Glycogen Debranching Enzyme System; Hydrogen-Ion Concentration; Maltose; Oligosaccharides; Recombinant Proteins; Substrate Specificity; Sulfolobus; Temperature

The complexation of fucosterol with three kinds of beta-cyclodextrin (beta-CyD) was investigated in aqueous solution and in the solid state. The solubility of fucosterol increased significantly on its complexation with maltosyl-beta-CyD and heptakis(2,6-di-O-methyl)-beta-CyD (DM-beta-CyD), while no appreciable increase was observed when complexed with beta-CyD. The stability constant of complexation with beta-CyD estimated from solubility determinations was greater for a 1:2 complex than for a 1:1 complex. On the other hand, 1:1 complexation of fucosterol with maltosyl-beta-CyD or DM-beta-CyD was greater than 1:2 complexation. The solid complexes were obtained in molar ratios of 1:2 and 1:3 for beta-CyD and maltosyl-beta-CyD complexes, respectively. The inclusion behaviour of fucosterol with maltosyl-beta-CyD was compared with beta-CyD in the solid state using DSC, powder X-ray diffractometry and CP/MAS 13C NMR. Maltosyl-beta-CyD showed different inclusion behaviour compared with beta-CyD, and produced an amorphous structure of fucosterol on complex formation. The dissolution rate of fucosterol-maltosyl-beta-CyD complex was significantly faster than other complexes due to its high aqueous solubility and amorphous structure.

Topics: beta-Cyclodextrins; Chemistry, Pharmaceutical; Cyclodextrins; Solubility; Solutions; Stigmasterol; Water