title: Resistance of highly branched (1-->3)-beta-D-glucans to formolysis.
abstract: Small molecular weight (MW) glucan derivatives could be a useful tool for studying the mechanisms of beta-glucan mediated biological activity, especially as antagonists for a beta-glucan receptor. This paper described the stability of various (1-->6) branched (1-->3)-beta-D-glucans to formolysis in the preparation of small MW derivatives. The glucans used were curdlan (linear), pachyman (few branches), GRN (one branch in every third main chain unit; 2/6), SPG (2/6), SSG (3/6), and OL-2 (4/6). Curdlan and pachyman were easily degraded to oligosaccharides by degradation for 20 min at 100 degrees C by 90% formic acid. However, branched glucans, especially the highly branched glucans, SSG and OL-2, were significantly resistant to degradation, and the majority remained high MW. SSG required a longer period and/or a higher temperature (121 degrees C treatment) to produce small MW derivatives. Branched glucans were also resistant to zymolyase (an endo-(1-->3)-beta-D-glucan hydrolase) digestion. These facts suggest that the (1-->6)-beta-D-branched residues contribute to the glucans' resistance to formic acid degradation and zymolyase digestion.
authors.affiliation: Lab. Immunopharmacology of Microbial Products, Tokyo University of Pharmacy and Life Science, School of Pharmacy, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ohno
authors.forename: T
authors.initials: T
authors.lastname: Terui
authors.forename: N
authors.initials: N
authors.lastname: Chiba
authors.forename: K
authors.initials: K
authors.lastname: Kurachi
authors.forename: Y
authors.initials: Y
authors.lastname: Adachi
authors.forename: T
authors.initials: T
authors.lastname: Yadomae
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000633:toxicity; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005561:Formates; D005936:Glucans / Q000737:chemistry* / Q000633:toxicity; D006867:Hydrolases / Q000737:chemistry; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008970:Molecular Weight; D012510:Sarcoma 180 / Q000188:drug therapy
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005561:Formates; D005936:Glucans; C037833:zymolyase; D006867:Hydrolases