Chemistry of phosphatide and wax D of Mycobacterium tuberculosis BCG in one week culture.

•g Purified wax•h as isolated by Anderson (1929), is a complex lipid extracted with chloroform from cultures of acid fast bacilli. Extracting the purified wax with boiling acetone, Asselineau (1951) obtained a soluble portion termed •gWax C•h and an insoluble residue, the •gWax D•h fraction. Likewise, the alcohol-ether soluble part of acid fast bacilli was classified into several fractions. •gPhosphatide•h is a boiling acetone insoluble residue in the alcohol-ether soluble fraction, corresponding to Wax D of the alcohol-ether insoluble and chloroform soluble fraction. Therefore, the substances contained in Wax D can be migrated from •gphosphatide•h depending on the conditions of extraction and on the metabolic stage of bacterial cells.