Abstract
The mucilage in Satoimo was extracted with water precipitated by making up to 75% ethylalcohol. After the precipitate was dissolved in the water and then dialyzed against the distilled water, it was precipitated with alcohol again and dried in a vacuum desiccator. The chemical properties of resulting browny white powder were studied. The results were as follows:
1. General composition: Moisture was 16%, crude ash was 4%, crude protein was 51% and total sugar was 16% (as glucose).
2. Qualitative reactions for identification of carbohydrates: Molish, Pinoff, Elson-Morgan, Phloroglucinol and Calbazol-sulfulic reactions were affirmative, while Fehling reaction was negative.
3. Carbohydrate composition: The sample was hydrolyzed (conditions of hydrolysis is shown in Fig. 1). Free carbohydrates were then identified by paper chromatography. As the results, 8 kinds of carbohydrates were found.
4. Color reactions for specific amino acid: Biuret, Ninhydrin, Sakaguchi, Hopkins-Cole, Xanthoprotein and Pauly reactions were all affirmative.
5. Amino acid composition: The sample was first hydrolyzed at 110°C for 32 hours in 6N-HCl. The free amino acid were then identified by paper chromatography. Consequently, 16 (or 17) kinds of amino acids were identified.
6. Identification of N-terminal amino acid residue: The sample was first reacted with FDNB. After DNP-peptide was hydrolyzed at 110°C for 16 hours in 6N-HCl, DNP amino acid was separated and then identified by paper chromatography and spectrophotometry. DNP-Gly, DNP-Ser, DNP-Asp were found.
7. Identification of C-terminal amino acid residue: The sample was first reacted with hydrazine at 100°C for 7 hours and then C-terminal amino acid was identified like N-terminal analysis. DNPThr was found.
