First Examples of H 2 S-Releasing Glycoconjugates: Stereoselective Synthesis and Anticancer Activities.

H2S donors are currently emerging as promising therapeutic agents in a wide variety of pathologies, including tumors. Cancer cells are characterized by an enhanced uptake of sugars, such as glucose. Therefore, novel glycoconjugated H2S donors were synthesized so that high concentrations of H2S can be selectively achieved therein. Dithiolethione portions or isothiocyanate portions were selected for their well-known H2S-releasing properties in the presence of biological substrates. A synthetic procedure employing trichloroacetimidate glycosyl donors was applied to produce, in a stereoselective fashion, C1-glycoconjugates, whereas C6-glycoconjugates were obtained by a Mitsunobu-based transformation. The resulting molecules were then tested for their anticancer effects on human pancreas adenocarcinoma ascites metastasis cell line AsPC-1. The most potent inhibitors of cell viability (6a beta and 7b) proved to release H2S inside the AsPC-1 cells and to alter the basal cell cycle.