Extraction of novel sulfated polysaccharides from <i>Aphanothece sacrum</i> (Sur.) Okada, and its spectroscopic characterization

Okajima-Kaneko, Maiko; Ono, Masateru; Kabata, Kiyotaka; Kaneko, Tatsuo

doi:10.1351/pac200779112039

Pure Appl. Chem., 2007, Vol. 79, No. 11, pp. 2039-2046

http://dx.doi.org/10.1351/pac200779112039

Extraction of novel sulfated polysaccharides from Aphanothece sacrum (Sur.) Okada, and its spectroscopic characterization

Maiko Okajima-Kaneko¹, Masateru Ono², Kiyotaka Kabata² and Tatsuo Kaneko¹

¹ School of Materials Science, Japan Advanced Institute of Science and Technology, Asahidai, Nomi, Ishikawa 923-1292, Japan
² School of Agriculture, Kyushu Tokai University, 5435 Minamiaso, Aso, Kumamoto 869-1404, Japan

Abstract: We extracted polysaccharides (PS) from Aphanothece sacrum using a hot alkaline solution which degraded other biopolymers such as proteins and nucleotides. The spectroscopy and elemental analyses indicated the PS contain carboxyls and sulfate groups. The degree of sulfation was estimated as about 10 mol %. ¹H NMR studies demonstrated that the PS of A. sacrum had a dimethylated fucose unit. The combination of sulfate group and fucose in the prokaryotic PS was first evidenced by the direct spectroscopic studies. The PS showed efficient gelation behavior, binding to metal ions abundant in soil, and the swelling volume of the gel was approximately 250 times the dry volume. These results imply that PS of A. sacrum, which has been mass cultivated in Japan for a long time, may have potential as an environmentally benign water absorbent.