1962 年 82 巻 10 号 p. 1376-1380
In order to examine the structure of the sugar moiety of the C substance, acetyl-ated (II and V) and formylated (III) derivatives of the C substance (I) and CR substance (IV) were prepared and their properties were examined. Functional groups in the sugar portion that are acylated are two hydroxyls and one amino group. The sugar portion becomes very unstable when (I) and (IV) are hydrolysed and difficult to isolate. Therefore, (I) and (IV) were deaminated to uronic acid derivative (VI) and hydrolysed under mild conditions by the use of cation-exchange resin, from which glucuronolactone (VIII) was isolated in crystalline form and identified with an authetic specimen. Reduction of this uronic acid derivative, followed by hydrolysis, and examination of its product by paper chromatography revealed a spot corres-ponding to glucose (X). The experimental evidences indicate the sugar moiety of the C substance is a uronic acid of hexosamine and takes the glucose configuration by deamination.