Sur la constitution chimique des acides mycoliques de deux souches humaines virulentes de Mycobacterium tuberculosis

Abstract

1. 1. Mycolic acid, which makes up 8.3% of the dry weight of the human tubercle bacillus Test, can be separated by chromatography into two acids (α and β) which are probably isomers. 2. 2. The elementary analysis of these two mycolic acids and a number of their derivatives confirms the molecular formula C 88H 176O 4 proposed by R. J. Anderson in 1938. Taking into account the difficulties inherent in the analysis of compounds of high molecular weight, this formula can be considered only as being the most probable. 3. 3. Specific reactions show that the hydroxyl group present in the mycolic acids is in the β-position with respect to the carboxyl group. 4. 4. The mycolic acids of the two virulent tubercle bacilli studied here have in the α-position an unbranched side chain containing 24 carbon atoms. The pyrolysis of mycolic acid, investigated by R. J. Anderson, which leads to n-hexacosanoic acid is thus explained. It is a reaction characteristic of β-hydroxy-acids having a side chain in the α-position. 5. 5. Mycolic acids, at least one of which is present in all the strains of Mycobacteria examined up to now, may be defined as β-hydroxy-acids of high molecular weight which contain a long aliphatic side chain in the α-position. This is a completely new aspect in the chemistry of the natural fatty acids.