Linear dextrins, complexation

Mild acidic hydrolysis (5mM HCl at 100 C) of cyclohepta-amylose gave an 8% yield of maltoheptaose. The first-order rate constant increased during hydrolysis because the a-(l - 4)-linkages of cyclohepta-amylose and linear dextrins are cleaved at different rates. Various thermodynamic parameters and the dependence of the rate of hydrolysis on pH and on complexation of cyclohepta-amylose with toluene were determined. 

Linear Dextrins. Both linear and cyclic maltodextrins in aqueous solution can form molecular complexes with other small molecules, possibly the most commonly known example being the blue... 

The plot of the reciprocal of k - kf against 1/[L] is linear, with a slope of 1 / [K(kc - kf)] and an intercept of 1 / (kc - kf). Figure 5.36 shows the stabilization of prostacyclin by the derivatives of P-cyclodextrin. However, not all inclusion complexes provide the stabilization of drugs. In many cases, drug degradation is enhanced via inclusion complex formation [e.g., prostaglandin E and E2/p-cyclo-dextrin (P-CD), aspirin/p-CD],... 

The location of the cation in these canal compounds is not clear, but the cation definitely influences the nature of the crystal which is formed. With sodium and lithium iodides, a form II type of complex crystallizes as hexagonal plates. In the sodium iodide-iodine complex, the inclusion compound is not stoichiometric but rather the iodine atoms are packed into the canals in linear rows, with a spacing not related to the spacing of the dextrin molecules. 

---