Mycobacterial sulfolipids: Spontaneous desulfation

A glycolipid sulfate elaborated in abundance by surface-grown cultures ofMycobacterium tuberculosis has been characterized in earlier studies as a complex 2,3,6,6′-tetraacyl α, α′ trehalose 2′-sulfate. The purified ammonium salt undergoes rapid quantitative desulfation on mere dissolution in reagent grade anhydrous ether. The same reaction is observed in sulfolipids recovered from a number of human strains and one bovine strain. Experimental observations on the normal and acid-catalyzed rates of the reaction and on the influence of other solvents and other cationic forms support a proposed mechanism, which is detailed. Structural criteria which may influence the proclivity for spontaneous desulfation are discussed.