1972 年 38 巻 2 号 p. 148-154
Chondroitin sulfate (CS) dissolved in water is difficult to precipitate with ethanol in the absence of salts, therefore suitable salts such as sodium acetate, calcium acetate must be added in order to complete precipitation. However, a detailed study concerning the influence of salts on the precipitation of CS with ethanol has not yet been reported.
In this paper, the precipitation of whale cartilage CS in aqueous solution with ethanol under various conditions was studied, and the following results were obtained.
1) The higher the CS or salt concentration, the less ethanol was needed to precipitate CS, and there was a linear relationship between the logarithm of CS or salt concentration and the ethanol concentration needed for the precipitation.
2) The decrease in temperature facilitated the precipitation of CS. Over 0°C, there was a linear relationship between the temperature and the ethanol concentration needed for the precipitation.
3) There were little differences in the precipitating power of various anions. In the case of cations, divalent cations possesed greater precipitating power than monovalent ones, and there were considerable differences in the precipitating power of equivalent cations.
4) The fractions obtained by fractionation of CS with ethanol were differed in molecular weight, and the ethanol concentration needed for the precipitation of CS was inversely proportional to the molecular weight.