Synthesis of the Tetrasaccharide Cap Domain of the Antigenic Lipophosphoglycan of Leishmania donovani Parasite

In this paper we report a new synthesis of the immunologically important tetrasaccharide terminal cap domain [Galp(1-4)-β-[Manp-(1-2)-α-Manp-(1-2)-α]-Manp] of lipophosphoglycan (LPG); the major cell surface GPI molecule and key virulence factor of the protozoan parasite Leishmania donovani. The synthetic approach provided a short convergent route for the LPG cap motif from lactose and mannose starting materials. The synthesis was then applied for the preparation of a radiolabelled cap epitope for macrophage receptor binding and immunological studies.