[Study on the mechanism of the interaction of methylene blue and sulfation pachymaran].

In order to understand the mechanism of the interaction of sulfate polysaccharides and small molecules at molecular level, the structure of pachymaran was decorated by Wolfrom, and sulfation pachymaran (SP) was prepared. The maximum binding number (N = 54) and the binding equilibrium constant (K = 1.563 x 10(6)) of the sulfation pachymaran and methylene blue (MB) were obtained by the exoterica model. The influence of the molar ratio of MB/SP, ethanol, hydroxypropyl-beta-cyclodextrin, Triton X-100 and NaCl on the spectra of MB-SP complex was investigated. The mechanism of the color changes of methylene blue and sulfation pachymaran reaction system has been discussed. The authors draw the conclusion that the color changes result mainly from the hydrophobic interaction between methylene blue molecules binding on sulfation pachymaran on the base of the electrostatic interaction of methylene blue and sulfation pachymaran.