CHEMICAL INVESTIGATION OF NEW POLYSACCH ARIDES FROM SHIRAIA BAMBUSICOLA
FANG JI-NIAN YE CHUN-QU LIU YU-RONG(Shanghai Institute of Materia Medica,Academia Sinica)
Shiraia bambusicola is a saprophytic Ascomycetes grown on bamboo in south China. Two new heteropolysaccharides, named SB1 and SB2, had been isolated from the mycelium. Both SB1 and SB2 were homogeneous. The component sugars of SB1 were D-glc, D-gal and L-ara in the molar ratio of 0.37:1:0.07 and SB2 were D-glc, D-gal, D-man and L-ara in the molar ratio of 0.25:1:0.47:0.12. The MW of SB1 and SB2 were 6000 and 25000, respectively. Methylation, periodate oxidation, Smith degradation and graded hydrolysis studies suggested that SB1 and SB2 possessed branch structure. The repeating units of SB1 contained 8 types of linkage. The main linkages were composed of 1,3- and 1,3,6-linked galactopyranosyl residues, 1,4- and 1,3,6-linked galactopyranosyl residues and a few 1,6-linked galactofuranosyl residues. The repeating units of SB2 contained 7 types of linkage. The main linkages were composed of 1,2- and 1,3,6-linked mannopyranosyl residues, 1,4- and 1,3,6-linked galactopyranosyl residues and a few 1,6-linked galactofuranosyl residues.