Commercial agar was subjected to complete hydrolysis with dilute sulfuric acid, and the products were carefully investigated. Besides D- and L-galactose, which have been known to exist, there were isolated small amounts of D-xylose, 6-O-methyl-D-galactose, 4-O-methyl-L-galactose, and O-methylpentose, all the sugars except the last one being obtained in crystalline forms. Among these products, 4-O-methyl-L-galactose
商品
琼脂用稀
硫酸完全
水解,仔细研究产品。除了已知存在的 D-和 L-半
乳糖外,还分离出少量
D-木糖、6-O-甲基-
D-半乳糖、4-O-甲基-L-半
乳糖和 O-甲基戊糖,除了最后一种糖以外的所有糖都是以结晶形式获得的。其中,4-O-甲基-L-半
乳糖是一种新化合物,对其结构进行了充分研究。由于商业
琼脂是由石花菜制成的,偶尔会与其他几种海藻混合,因此只对由石花菜制备的
琼脂重复了实验。除了O-甲基戊糖外,分离出与商品
琼脂相同的产品。