Synthesis of glycoconjugate fragments of mycobacterial phosphatidylinositol mannosides and lipomannan.

ABSTRACT: Mycobacterium tuberculosis, the causitive agent of tuberculosis (TB), possesses a complex cell wall containing mannose-rich glycophospholids termed phosphatidylinositol mannosides (PIMs), lipomannan (LM), and lipoarabinomannan (LAM). These glycophospholipids play important roles in cell wall function and host-pathogen interactions. Synthetic PIM/LM/LAM substructures are useful biochemical tools to delineate and dissect the fine details of mannose glycophospholipid biosynthesis and their interactions with host cells. We report the efficient synthesis of a series of azidooctyl di- and trimannosides possessing the following glycan structures: ?-Man-1,6-?-Man, ?-Man-1,6-?-Man-1,6-?-Man, ?-Man-1,2-?-Man-1,6-?-Man and 2,6-di-(?-Man)-?-Man. The synthesis includes the use of non-benzyl protecting groups compatible with the azido group and preparation of the branched trisaccharide structure 2,6-di-(?-Man)-?-Man through a double glycosylation of a 3,4-butanediacetal-protected mannoside. The azidooctyl groups of these synthetic mannans were elaborated to fluorescent glycoconjugates and squaric ester derivatives useful for further conjugation studies.

SUBMITTER: Cao B 

PROVIDER: S-EPMC3079179 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature