Chemistry of the Lipoids of Tubercle Bacilli

Abstract

The phosphatide A-3 obtained from the human type of tubercle bacilli, strain H-37, 1 yielded on hydrolysis about 33% of water-soluble material, but when the preliminary analysis was published only 2 of the water-soluble constituents had been identified, viz., glycerophosphoric acid and glucose. Mention was made in the former publication 1 that a slightly soluble phenylhydrazine derivative was obtained from the aqueous solution and this compound was regarded as a phenylhydrazine salt of a sugar acid. In addition, we also obtained a small amount of a colorless crystalline compound from the concentrated syrup. This unidentified substance was more specifically referred to in the paper dealing with the analysis of the phosphatide isolated from the avian tubercle bacilli. 2 We have recently examined more thoroughly the sugar fractions obtained from the phosphatide A-3 as well as those obtained from the phosphatide from the avian bacillus and we have been able to identify 2 other substances which are present in the hydrolysis mixture, viz., mannose and inosite.

The separation of the water-soluble constituents was accomplished as follows: After hydrolysis with boiling dilute sulfuric acid the fatty acids were extracted with ether and the aqueous solution was freed of sulfuric acid quantitatively with barium hydroxide. After the solution had teen filtered it was concentrated under reduced pressure, neutralized with barium hydroxide, and the barium phosphate and barium glycerophosphate were precipitated by adding alcohol and removed by filtration. A slight amount of barium in the filtrate was removed quantitatively with sulfuric acid and the solution was concentrated to a thin syrup. An excess of phenylhydrazine dissolved in a little alcohol was added when a crystalline derivative separated almost immediately. After the crystals had been filtered off the excess of phenylhydrazine was removed from the filtrate by treatment with phenzaldehyde.