Chemoselective Protection of Glutathione in the Preparation of Bioconjugates: The Case of Trypanothione Disulfide

A novel synthetic route to the chemoselectively protected N,S-ditritylglutathione monomethyl ester is described involving the chemical modification of the commercially available glutathione (GSH). The synthetic value of this building block in the facile preparation of GSH bioconjugates in a satisfying overall yield was exemplified by the case of trypanothione disulfide (TS2), a GSH-spermidine bioconjugate, involved in the antioxidative stress protection system of parasitic protozoa, such as trypanosoma and leishmania parasites.