Click chemistry oligomerisation of azido-alkyne-functionalised galactose accesses triazole-linked linear oligomers and macrocycles that inhibit Trypanosoma cruzi macrophage invasion

Reaction of 2-(2-(2-azidoethoxy)ethoxy)ethyl 6- O-(prop-2-ynyl)-b-D-galactopyranoside (7 ) under CuAAC conditions gives rise to mixed cyclic and linear triazole-linked oligomers, with individual compounds up to d.p. 5 isolable, along with mixed larger oligomers. The linear compounds resolve en bloc from the cyclic materials by RP HPLC, but are separable by gel permeation chromatography. The triazole-linked oligomers dpseudo-galactooligomersd were demonstrated to be acceptor substrates for the multi-copy cell surface trans-sialidase of the human parasite Trypanosoma cruzi . In addition, these multivalent TcTS ligands were able to block macrophage invasion by T. cruzi .