Chemical Studies on the Specific Fragment of Shigella sonnei Phase II

Abstract

The pure lipopolysaccharide of Shigella sonnei phase II was submitted to acid hydrolysis (0.1 N H2SO4, 20 min, 100°), and from the hydrolyzate the specific fragment was isolated and purified. The analysis of the specific fragment showed that it contained about 70% sugar; the major constituents were glucose, galactose and heptose in the approximate proportion 3:2:2.2. 2-Keto-3-deoxyoctonate (3.2%), glucosamine (3.4%) and O-phosphorylethanolamine (6.0%) were also found. The molecular weight of the specific fragment estimated by gel filtration ranged between 4,500–5,000. Electrophoretic experiments indicated its acid character: the isoelectric point was near 2.9.