Characterization of 3-Amino-3,6-dideoxy-d-glucose from a Bacterial Lipopolysaccharide

Lipopolysaccharides were isolated from Citrobacter freundii ATCC 8090 by 44% aqueous-phenol fractionation. The lipopolysaccharides were isolated from the phenol phase and phenol-water interphase fractions. Acid hydrolysis yielded glucosamine and a 3-amino sugar identified as 3-amino-3,6-dideoxyglucose by comparison with authentic 3-amino-3,6-dideoxyhexoses by ion exchange chromatography. Comparison of the 3-acetamido-1,2,4-tri-O-acetyl-3,6-dideoxyhexose with 3-acetamido-1,2,4-tri-O-acetyl-3,6-dideoxy-l-glucose was made. The infrared spectra were identical, while the optical rotatory dispersion curves were identical in shape but opposite in sign. The compound isolated from C. freundii was thus assigned the structure 3-amino-3,6-dideoxy-d-glucose.