THE WATER-SOLUBLE POLYSACCHARIDES OF DERMATOPHYTES: V. GALACTOMANNANS II FROM TRICHOPHYTON GRANULOSUM, TRICHOPHYTON INTERDIGITALE, MICROSPORUM QUINCKEANUM, TRICHOPHYTON RUBRUM, AND TRICHOPHYTON SCHÖNLEINII

Abstract

Polysaccharides obtained from each of the organisms designated in the title have been resolved into three groups: galactomannans I, galactomannans II, and glucans. The five galactomannans II were homogeneous under conditions of electrophoresis, and had positive specific rotations. Methylation and hydrolysis of the five galactomannans II yielded varying amounts of the following: 2,3,5,6-tetra-O-methyl-D-galactose, 2,3,4,6-tetra-O-methyl-D-mannose, 2,3,4-tri-O-methyl-D-mannose, 3,4,6-tri-O-methyl-D-mannose, 3,5-di-O-methyl-D-mannose, and 3,4-di-O-methyl-D-mannose. The galactomannans II were therefore very similar to each other in their gross structural features. The unbranched portions of the polysaccharides were formed by 1 → 2 and 1 → 6 linked α-D-mannopyranose units, with the former predominating. Branch points were formed through substitutions at the C-2 and C-6 positions of D-mannofuranose and D-mannopyranose, and branches were terminated by D-galactofuranose and D-mannopyranose units. The presence of 1 → 2 linked α-D-mannopyranose units in the linear portions of the galactomannans II constitutes a major structural difference between this group of polysaccharides and the galactomannans I. The two groups of galactomannans differ serologically.