Thiolactosides: Scaffolds for the Synthesis of Glycolipids in Animal Cells

Various glycolipids were synthesized using thiolactosides as scaffolds for glycosylation in animal cells. The basic building blocks, n-dodecyl β-D-thiolactoside (β-LacSC12) and n-dodecyl α-D-thiolactoside (α-LacSC12), were chemically synthesized in 2 steps: glycosylation followed by deacylation. The thiolactosides were administered to animal cells in culture and served as substrates for cellular enzyme-catalyzed glycosylation. Incubation of mouse melanoma B16 cells in the presence of β-LacSC12 or α-LacSC12 resulted in sialylation of the terminal galactose residue and gave a GM3-type ganglioside. Administration of β-Lac SC12 in Madin-Darby canine kidney (MDCK) cells likewise gave a GM3-type ganglioside. On the other hand, introduction of β-LacSC12 in African green monkey kidney (Vero) cells gave Gb3- and Gb4-type glycolipids aside from GM3-type ganglioside. In the course of the study, significant changes in B16 cell morphology and elevated secretion of melanin were also observed.