[#1986-06] Two Different Conformations of Antitumor Glucans Obtained from Grifola frondosa, Naohito Ohno et al.

Two Different Conformations of Antitumor Glucans Obtained from Grifola frondosa

Ohno, N (a), Adachi, A (a), Suzuki, A (a), Oikawa, S (b), Sato, K (b), Suzuki, Y (b), Ohsawa, M (b), Yadomae, T (a)

a) Tokyo College of Pharmacy, b) Nippon Beet Sugar Mfg. Co. Ltd.

Several antitumor glucan fractions obtained by various extraction procedures from Grifola frondosa ( maitake ) were compared by solution and solid (cross polarization, magic angle spinning (CP/MAS)) carbon-13 nuclear magnetic resonance (¹³C-NMR) spectroscopy. The fractions prepared under milder conditions, i.e. hot water extract (AHW), liquid culture filtrate (LLFD), and extracellular polysaccharide (LELFD), showed a C-3 signal at the same chemical shift as that in DMSO-d₆ solution (native form) in ¹³C-CP/MAS NMR spectroscopy. However, the fractions prepared under drastic conditions, i.e. cold alkali extract (NMF-5, grifolan) showed a C-3 signal at 89 ppm, similar to those of curdlan and attributable to helix structure (helix form). After dissolution of LELFD in 8M urea followed by dialysis, LELFD also showed a C-3 signal at 89 ppm. These results suggest that the polysaccharides obtained from G. frondosa possess two kinds of conformations.