Fractionation and Characterization of Antitumor Polysaccharides from Maitake, Grifola frondosa

Abstract

Three groups of polysaccharides from the edible mushroom "Maitake, " the cultured fruiting body of Grifola frondosa, were extracted with hot water, 3% NH₄-oxalate (100°C), and 5% sodium hydroxide solution (30°C) in this order. The three fractions, FI, FII and Fill, were divided into several sub-fractions using various chromatographic techniques.
The fractions with host-mediated antitumor activity were as follows:
Water-soluble β-(1→ 3)-o-glucan: FI₀-a-β₁, [α]_D +9° (water), MW 1, 000, 000, N 0%, degree of branching = 3, average chain-length = 5, ID₅₀ (the dose level, mg/kg in mice, inhibiting tumor growth in 50% of animal controls) = 5.8.
Water-soluble acidic β-D-glucan: FA-la-β₁, [a]_D +5° (water), MW 500, 000, component sugars; Glc 82.4% and GlcUA 8.8%, ID₅₀=12.9.
Water-insoluble acidic xyloglucan: FII-3, [α]_D + 56° (NaOH), MW 50, 000, component sugars; Glc:Xyl=100:82, GlcUA 16.5%, ID₅₀ = 23.8.
Acidic hetero-glycan: Fill-la, [α]_D +6° (NaOH), MW 100, 000-250, 000, protein content 3.8%, component sugars; Glc:Xyl: Man: Fuc= 100: 58:34:14, GlcUA 20.4%, ID₅₀ = 16.1.
Acidic glycoproteins: FIII-2a, FIII-2b and FIII-2c: [a]_D +58°, +43°, -11° (NaOH); MW 1, 000, 000, 70, 000- 100, 000, 20, 000- 50, 000; ID₅₀= 38.5, 13.9, 9.3 respectively; component sugars; major = Glc, minor = Fuc, Xyl, Man, and Gal.
None of the polysaccharides intraperitoneally active against mouse-implanted Sarcoma 180 had any activity orally.