Capsular and Cell-Wall Materials

Liu and Gotschlich (1963) have used infrared methods to identify o-galactosa-mine 6-phosphate, a major constituent of pneumococcal C-polysaccharide. This was the first time that this sugar derivative had been isolated and identified in bacterial cell walls. 

Heymann et al. (1963) have prepared the group-specific C-polysaccharide of Group A hemolytic streptococci and found (1 — 3)-linked rhamnose units. Side groups or side chains were linked to the 2-position of rhamnose. Infrared spectra pointed to the existence of a-glycosidic linkages between the rhamnose units. 

In a study (Heymann et al, 1964) involving the structure of deacetylated C-poly-saccharide of Group A hemolytic streptococci, infrared spectroscopy has been used to observe the disappearance of amide absorption as a result of treatment at 100°C with 0.49N barium hydroxide. 

Infrared spectroscopy has been useful in identifying two disaccharides as products of the hydrolysis of the cell wall of S. aureus by an acetylmuramidase and an amidase from Streptomyces albus G (Ghuysen and Strominger, 1963). These disaccharides were )S-l,6-Af-acetylglucosaminyl-Af-acetylmuramic acid and ) -l,6-Af-acetylglucosaminyl-Af,4-0-diacetylmuramic acid. 

Eremin et al. (1965) have precipitated carbohydrate material with ethanol after alkaline hydrolysis of cultures of Whitmore s bacillus Pseudomonas pseudomailer), Pasteurella pestis, and Vibrio comma, and have subjected these polyoses to infrared spectroscopy. All spectra had strong absorption at 1660 and 1550 cm the former was related to double-bond vibrations and the latter was associated with stretching vibrations of C—N. The latter absorption was almost completely absent in the spectrum of a complex from V. comma. Absorption at 970 cm (the C=C double bond in the trans position) and traces of absorption at 790 cm characteristic of the 1 — 3 bond were always present. A polysaccharide from the cell wall of P. pestis had a wide band at 1170-1000 cm the low intensity bands at 1190 and 1160cm indicated the presence of P—O—Me and P—O—Et groups. The spectrum of a complex from Whitmore s bacillus differed from the others by the presence of a band at 1735 cm due to esters of fatty acids. 

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