A study of the glucosamine-containing constituents of the seeds of kidney beans (Phaseolus vulgaris)

1. The constituents of the seeds of kidney beans containing glucosamine that could be released by acid hydrolysis (0·5 n-hydrochloric acid at 100°) were extracted into the phenol-rich phase on partitioning between phenol and water at 70°. 2. These materials were also brought into solution on extracting the seeds with water (incomplete), or preferably with a slightly alkaline buffer in the absence of phenol. When these solutions were heated at 100° or treated with trichloroacetic acid, all the materials containing acid labile glucosamine were carried down with the precipitate. Treatment with pepsin rendered the materials containing glucosamine soluble again. 3. All proteins in these extracts of kidney bean were found to be associated with various amounts of neutral and amino sugars by high-voltage electrophoresis and chromatography on Sephadex G-200 columns. 4. The isolation and crystallization of the main sugar components, d-glucosamine and d-mannose, are described and their significance in plant glycoproteins is discussed.