Total Synthesis of Membrane Lipids from Mycobacterium tuberculosis

The bacterial pathogen Mycobacterium tuberculosis (Mtb) poses a significant health challenge, tuberculosis disease (TB), to humanity. The (glyco)lipids, from the cell wall of Mtb, exhibit immunological properties and hold potential as vaccine adjuvants. This thesis elaborates the structure determination and structure revision of di-O-acyl-trehalose (DAT2) and its methyl-branched acyl substituent (mycolipanolic acid), tri-O-acyl-trehalose (TAT), tetra-O-acyl-trehalose (TetraAT) and lysyl-diacylglycerol. Efficient chemical synthesis routes have been developed for the asymmetric total synthesis of their stereoisomers and are accompanied by analysis using NMR, HPLC, GC, and mass spectrometry. Biological assays demonstrated that the natural stereoisomer of DAT2 markedly activates the macrophage receptor Mincle, highlighting its antigenicity and potential applications in serodiagnostics and vaccine adjuvants. Based on the structural correction of penta-O-acyl-trehalose (PAT) and our synthesized biosynthetic intermediates TAT and TetraAT, we rule in our hypothesis for the biosynthesis of PAT. Additionally, attempts to synthesize N’-carboxymethyl lysyl diacylglycerol and a novel trehalose probe equipped with a geminal chloro-nitroso unit are reported which, although currently unsuccessful, indicate a need for further exploration. In conclusion, we have completed the total synthesis of DAT2, TAT, TetraAT and lysyl-diacylglycerol and their structural determination using chromatographic and spectroscopic analytic methods. Further research will be required for the synthesis of N’-carboxymethyl lysyl diacylglycerol and geminal chloro-nitroso trehalose and potential applications of the synthesized acylated trehaloses in vaccine adjuvant development.