Structural features and hypoglycemic activities of two polysaccharides from a hot water extract of agrocybe cylindracea英文电子书.pdf

Carbohydrate Research, 251(1994) 81-87 81 Elsevier Science B.V., Amsterdam Structural features and hypoglycemic activities of two polysaccharides from a hot-water extract of Agrocybe cylindracea ?y* Tadashi Kiho, Satoshi Sobue and Shigeo Ukai * Gifu Pharmaceutical Universily, 5-6-l Mitahora-higashi, Gifu 502 (Japan) (Received January 25th, 1993; accepted July 7th, 1993) ABSTRACT A glucan (AG-HNl, [a]o +24”) and a heteroglycan (AG-HN2, [a], +26”1 were isolated from a hot-water extract of the fruiting bodies of Agrocybe cylindracea. The structures were investigated by a combination of chemical and spectroscopic methods. The results indicated that high molecular weight glucan AG-HNl is primarily a B-(1 + 6)-branched (14 3)-P-p-glucan containing small amounts of (1 + 4)-linked and (1 + 6)-linked glucopyranosyl residues. Low molecular weight heteroglycan AG-HN2 gives galactose, glucose, fucose, and mannose on hydrolysis and appears to be chiefly composed of (14 6)-linked gluco- and galacto-pyranosyl residues, many of them branched, and various nonreducing terminal residues. AG-HNl showed a remarkable hypoglycemic activity in both normal and streptozo- tocin-induced diabetic mice by ip administration, and its activity was higher than that of AG-HN2. INTRODUCTION PreviousIy, we reported on a linear (1 --t 3)-a-o-glucan (AG-AL) from an alkaline extract of the fruiting bodies of Agrocybe cylindruceu (Fr.) Maire and the antitumor activity of 0-(carboxymethyl)ated AG-AL derivatives2. It has be