The chemistry of the lipides of tubercle bacilli; concerning inositol glycerol diphosphoric acid, a component of the phosphatide of human tubercle bacilli.

In studies conducted in this laboratory dealing with the composition of the phosphatide isolated from the human tubercle bacillus, strain H-37, it was recognized early that an organic phosphoric acid of the formula C9H20014P2 could be separated in the form of the barium salt from the water-soluble cleavage products after the phosphatide had been saponified with alcoholic potassium hydroxide (I). This substance was regarded as a complex composed of a hexose monophosphoric acid and glycerophosphoric acid. The acid gave no reduction with Fehling’s solution until it had been refluxed for some time with dilute sulfuric acid. The presence of a reducing sugar was thus demonstrated, but the sugar was not identified at that time. A compound of similar composition was also isolated from the cleavage products of the phosphatide of the leprosy bacillus (2). In a later investigation (3) of the organic phosphorus compounds contained in the phosphatide of the human tubercle bacillus, strain H-37, a barium salt was isolated which corresponded in composition to the formula CSHIGO~JP~B~+ Analysis of this substance indicated that it was mannose glycerol diphosphoric acid. The reducing sugar cantained in this compound was identified as mannose. In addition to the acid of the formula CgH20014P2, the isolation of glycerophosphoric acid (4), inositol monophosphoric acid (5, 6), and the phosphorus-containing glycoside manninositose (1,3) has been described. The isolation of an acid of the formula C9H20014P2 in the form of the barium salt was described in the preceding paper (6) and it was suggested that the substance was inositol glycerol diphosphoric acid. The substance