STRUCTURAL RELATIONSHIPS OF EXTRACELLULAR POLYSACCHARIDES FROM PHYTOPATHOGENIC XANTHOMONAS SPP.: PART I. STRUCTURE OF THE EXTRACELLULAR POLYSACCHARIDE FROM XANTHOMONAS STEWARTII

Abstract

Xanthomonasslewartii produces an extracellular polysaccharide which is markedly different from those formed by other Xanthomonas spp. examined in that it gave glucose, galactose, and an aldobiouronic acid on hydrolysis. Methylation followed by hydrolysis yielded 2,3,4,6-tetra-O-methyl-D-glucose (4 parts), 2,3,4-tri-O-methyl-D-glucose (2 parts), 2,4,6-tri-O-methyl-D-galactose (1 part), 2,3,4-tri-O-methyl-D-galactose (2 parts), and 2-O-methyl-D-galactose (1.8 parts). Partial acid hydrolysis yielded 6-O-β-D-glucopyranosyl-D-galactose, 3-O-β-D-glucopyranosyl-D-galactose, 3-0-β-D-galactopyranosyl-D-galactose, and 4-O-β-D-glucuronopyranosyl-D-galactose.