アルカリ溶解法による鯨鼻軟骨からのコンドロイチン硫酸の製法-I

Abstract

The present paper deals with an investigation on alkaline liquefaction method, by which crude sodium chondroitin sulfate for medical purpose can be manufactured easily from whale nasal cartilage. The cartilage was boiled in water and dissolved in a small amount of sodium hydroxide so-lution at above 30°C in order to raise the efficiency of extraction. Dialysis, deproteinization at pH 3.5 and neutralization were succesively performed and then sodium chondroitin sulfate was precipitated with ethanol. The influence of conditions for liquefaction upon yield and purity of the product was in-vestigated and the following results were obtained. 1) The cartilage could easily be dissolved in 5-50% sodium hydroxide at 40°C in an hour, while in the case of 3% sodium hydroxide considerable residue remained. The higher the concentration of sodium hydroxide solution was, the higher the purity of the product was. The purity of the product obtained with 50% sodium hydroxide was 96% (Nitrogen content, 3.3%) (Table 1). 2) When 10% sodium hydroxide was used, the influence of temperature (30-60°C) and time (1-5 hrs.) for the liquefaction upon the purity of the product was not so great (Table 2, 3). 3) In order to manufacture the product of high purity and yield, it was required to heat 100g. cartilage in 25ml. of 50% sodium hydroxide at 40°C for 90 minutes (Table 4). 4) The concentrating procedure of the deproteinized solution before ethanol precipitation caused the purity of the product to decrease appreciably (Table 5).