Spectrométrie de masse de glycolipides

Abstract

“Cord factors” are diesters of α,α‐trehalose produced by Mycobacteriae and Corynebacteriae. Saponification of the “cord factor” of Corynebacterium diphtheriae gives an equimolecular mixture of homologues of the saturated corynomycolic and of the unsaturated corynomycolenic acids (I and II, R = H). Máss spectrometry of their methyl esters confirms their structures (see Fig. 1, R = CH 3 ). The peracetylated cord factor (IV, a, b, c) gave very weak molecular ions at m/e 1630, 1632 and 1634 showing apparently that it is a mixture of the diesters having respectively two saturated, one saturated and one unsaturated, and two unsaturated acyl radicals. Strong peaks at m/e 809 and 807 are attributed to the oxonium ions (V a and V b). These results as well as chemical degradations show that the “cord factor” of C. diphtheriae is a mixture of glycolipids (III a, b, c).