title: Structure and antitumor activity of an alkali-soluble polysaccharide from Cordyceps ophioglossoides.
abstract: A water-insoluble extracellular glucan (CO-1) was isolated from the precipitate formed on incubation of the culture filtrate of Cordyceps ophioglossoides at 37 degrees for 19 h. CO-1 was homogeneous as judged by h.p.l.c., electrophoresis, and ultracentrifugation, and the average molecular weight was determined by h.p.l.c. to be 632,000. The 1H- and 13C-n.m.r. and the i.r. spectra indicated that the glucosidic linkages in CO-1 were beta. From the results of methylation analysis, Smith degradation, n.m.r. studies, and enzymic hydrolysis, it was concluded that CO-1 is composed of a backbone of (1----3)-linked beta-D-glucopyranosyl residues with a beta-D-glucopyranosyl group attached to O-6 of every second D-glucopyranosyl residue of the backbone. CO-1 strongly inhibited the growth of Sarcoma 180 solid-type tumor. CO-1 polyalcohol, which was prepared by Smith degradation of CO-1, exhibited more-potent antitumor activity than CO-1. The absorption maximum of Congo Red shifted significantly in the presence of CO-1.
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D006999:Hypocreales / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D011134:Polysaccharides / Q000302:isolation & purification* / Q000627:therapeutic use; D012510:Sarcoma 180 / Q000188:drug therapy*; D013055:Spectrophotometry, Infrared
chemical_list: D000970:Antineoplastic Agents; D011134:Polysaccharides