Sur la structrue chimique des cires D, peptidoglycolipides macromoléculaires des souches humaines de Mycobacterium tuberculosis

A sample of Wax D, a macromolecular peptidoglycolipid of Mycobacterium tuberculosis , was purified by column chromatography on silicic acid and then analysed. It contains about 90% of a mycolate of arabinogalactan and 8% of a phosphorylated mucopeptide. The structure of the mycolate of arabinogalactan shown in Fig.2 is based on the isolation of the following products of partial hydrolysis: (a) mycolates of arabinofuranose and arabinobiose, in which mycolic acids are esterified to the 5‐OH of arabinofuranose; (b) a 1→4 diagalactopyranoside; (c) a 1→4 arabinogalactoside; (d) an arabinodigalactoside having two 1→4 linkages. The structure of the phosphorylated mucopeptide is shown in Fig. 3 B, as compared to that proposed by Migliore and Jollès [30] (Fig. 3 A). The discrepancy between these two structures might be due to different methods of purification of Wax D and of isolation of the mucopeptide. These results as well as previous work of Azuma et al. [21], Migliore and Jollès [30], Kanetsuna and San Blas [32] lead to a hypothetical structure of Wax D shown in Fig.4. The origin of Wax D is discussed; as already suggested by work of Kanetsuna and San Blas [32] and David et al. [34], Wax D is thought to be the result of partial enzymatic degradation of the cell wall.