A glucomannan from Arum korolkovii
SummaryA glucomannan has been isolated from the tubers ofArum korolkovii Regel. It has been shown that the polysaccharide contains O-acetyl groups and consists mainly of (1 → 4)-β-linked aldohexopyranose units of glucose and mannose in a ratio of 1:1.6. The nonreducing ends of the glucomannan are glucose residues, and branching is localized at C2 and C3 of mannose.
A glucomannan from the tubers of Arum orientale
Abstract Two glucomannans ( A and B ), and an attendant polysaccharide ( C ) have been isolated from the tubers of Arum orientale (L.) by gel chromatography. Glucomannan B was found to be composed of d -glucose and d -mannose in a molar ratio of 2:3·1, and traces of uronic acid. IR spectra, enzymatic hydrolysis with α- and β-amylase, and periodate oxidation followed by reduction, showed the presence of a β-(1→4) glucoside linkage in this glucomannan, and of hexose residues in a β-pyranose form.
The relation of food quantity to rumination behavior.
Preliminary work suggested that the quantity of food ingested by retarded individuals who usually ruminated following meals was related to the frequency and duration of ruminating responses. This possible relation was experimentally examined by systematically varying food quantity from regular portions to satiation levels for three retarded individuals who exhibited high levels of ruminating. A clear functional relation of food quantity to ruminating emerged, with satiation procedures producing rapid and large decreases in the relatively high frequencies and durations of ruminating characteristic of baseline food quantity conditions.