Plant Mucilages. XXXIII. An Acetyl-Rich Mucilage, "Lycoris-S-glucomannan, "from the Bulbs of Lycoris squamigera

A mucilage, named Lycoris-S-glucomannan, was isolated from the bulbs of Lycoris squamigera MAXIM. The final preparation was homogeneous as determined by ultracentrifugal analysis, glass-fiber electrophoresis, and gel chromatography. It was mainly composed of D-mannose and D-glucose in the molar ratio of 7 : 2, and its molecular weight was estimated to be about 1800000. O-Acetyl groups were identified in the glucomannan and their content amounted to 16.7%. They were located at positions 2, 6 of about half of the D-mannose units. Methylation, periodate oxidation, and partial acid hydrolysis studies showed that the glucomannan is mainly composed of β-1→4 linked aldohexopyranose residues, and that it contains about twenty aldohexose units per three non-reducing groups on average. D-Mannose units occupy all branching points linked through position 3, while both D-mannose and D-glucose units occupy non-reducing terminal positions.