Purification of an antitumor-active, branched (1----3)-beta-D-glucan from Volvariella volvacea, and elucidation of its fine structure.
A (1--3)-beta-D-glucan branched by O-6 substitution (FCAP), obtained from the cold-alkali extract of the fruiting body of V. volvacea, exhibited potent growth-inhibitory activity against implanted tumors in mice. It contained protein and appeared to be heterogeneous. Fractionation by DEAE-Toyopearl column chromatography yielded an unbound, protein-free glucan fraction ([alpha]D - 30 degrees in M NaOH, mol. wt. 1.5-2 x 10(6)), which showed the highest antitumor activity. The polysaccharide had a moderately branched structure, consisting of a backbone chain of beta-(1--3)-linked-D-glucose residues, one out of five or six being substituted at O-6 with single glucosyl of beta-(1--6)-linked diglucosyl groups. Digestion of the glucan with exo-(1--3)-beta-D-glucanase yielded glucose and ++gentiobiose (molar ratio, 8:2:1.0), and a highly branched (d.b. 1/3), degraded glucan. Digestion with endo-(1--3)-beta-D-glucanase gave D-glucose, laminarabiose, a trisaccharide beta-D-Glcp-(1--6)-beta-D-Glcp-(1--3)-D-Glc, a tetrasaccharide beta-D-Glcp-(1--3)-beta-D-Glcp-(1--3)-[beta-D-Glcp-(1--6)]-D-Glc, and a highly branched (d.b. 1/2), enzyme-resistant glucan. The results suggest that the Volvariella glucan is structurally heterogeneous with regard to the distribution of branches, having less branched, moderately branched, and highly branched segments.
Kishida
E
E
Department of Food and Nutrition, Faculty of Science of Living, Osaka City University, Japan.
Sone
Y
Y
Misaki
A
A
D000363:Agaricales / Q000032:analysis*; D000818:Animals; D000970:Antineoplastic Agents / Q000302:isolation & purification*; D002240:Carbohydrate Sequence; D005591:Chemical Fractionation; D002852:Chromatography, Ion Exchange; D005260:Female; D005936:Glucans / Q000302:isolation & purification* / Q000494:pharmacology; D006868:Hydrolysis; D008745:Methylation; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012510:Sarcoma 180 / Q000188:drug therapy
D000970:Antineoplastic Agents; D005936:Glucans