Studies on hemicelluloses

cobs have long been recognised as a source of xylose, which may be obtained from them in a pure condition and in fairly high yield. More recently, a method for the preparation of xylose from this source has been described by Ling and Nanji [1923], who obtained the sugar in 10-12 % yield. This xylose arises, at least in part, by the hydrolysis of hemicelluloses present in the cobs. After a preliminary treatment with dilute ammonia, the cobs were extracted with sodium hydroxide solution, the hemicellulose being precipitated by addition of alcohol. The product yielded xylose on hydrolysis, other sugars not being detected, while as a result of elementary analysis the formula (C5H804)n was ascribed to it.