The emission of corrosive vapours by wood. Sweet-chestnut (Castanea stiva) and wych-elm (Ulmusglabrau) O-acetyl-4-O-methylglucuronoxylans extracted with dimethyl sulphoxide.
作者信息
Cochrane G C, Gray J D, Arni P C
出版信息
Biochem J. 1969 Jun;113(2):243-52. doi: 10.1042/bj1130243.
O-Acetylated 4-O-methylglucuronoxylans were isolated from sweet chestnut and wych elm, either green or incubated at 48 degrees and 100% relative humidity for 36 weeks. 2. The chlorine-ethanolamine method of delignification resulted in a 50% loss of O-acetyl groups from green wych elm compared with an 18% loss from green sweet chestnut. 3. The acid-chlorite method gave an acceptable loss of O-acetyl groups in three cases, but incubated sweet chestnut showed a 44.6% loss. However, it is believed that this is due to the loss of simple O-acetylated xylose sugars resulting from glycosidic hydrolysis, rather than removal of O-acetyl groups by direct hydrolysis. Assuming that this occurs in a random manner, it is unlikely to have much structural significance. 4. Dimethyl sulphoxide extraction of chestnut holocellulose and elm holocellulose, green and incubated, yielded O-acetyl glucuronoxylans containing 10.2, 3.8, 13.1 and 7.7% O-acetyl groups respectively. 5. The location of these O-acetyl groups was determined by Bouveng's method in which phenyl isocyanate is used as a blocking group.
摘要
从甜栗和 wych 榆中分离出 O - 乙酰化 4 - O - 甲基葡糖醛酸木聚糖，这些样本要么是新鲜的，要么在 48 摄氏度、相对湿度 100% 的条件下孵育 36 周。2. 与绿色甜栗 18% 的乙酰基损失相比，用氯乙醇胺法脱木质素导致绿色 wych 榆的乙酰基损失了 50%。3. 酸亚氯酸盐法在三种情况下乙酰基损失可接受，但经孵育的甜栗显示有 44.6% 的损失。然而，据信这是由于糖苷水解导致简单的 O - 乙酰化木糖糖损失，而非通过直接水解去除乙酰基。假设这种情况以随机方式发生，不太可能具有太多结构意义。4. 对新鲜和经孵育的栗木全纤维素和榆木全纤维素进行二甲基亚砜提取，分别得到含 10.2%、3.8%、13.1% 和 7.7% 乙酰基的 O - 乙酰葡糖醛酸木聚糖。5. 这些 O - 乙酰基的位置通过 Bouveng 法确定，该方法使用异氰酸苯酯作为封闭基团。
