A Study of Hydroxyethyl Starch. Part V. Some Physicochemical and Biological Properties of Hydroxyethyl Starch Isolated from the Blood and Urine, and Limit Hydroxyethyl Starch

Abstract Hydroxyethyl starch (HES) was isolated from blood and urine, and also limit HES was isolated which was obtained by exhaustive degradation of HES by α‐amylase. From the study on their physicochemical properties and molecular‐size distributions, the results were obtained that [η] and molecular substitution (M. S.) of HES isolated from the blood were almost unchanged, while [η] of HES isolated from urine was decreased and M. S. of it was slightly changed. Furthermore, it was calculated that limit HES contained only about 1.5% of higher‐molecular‐weight fractions against the amount of parent HES than those of HES excreted in urine.