2-O-β-d-Glucopyranosyl-sn-glycerol based analogues of sulfoquinovosyldiacylglycerols (SQDG) and their role in inhibiting Epstein-Barr virus early antigen activation

New sulfoquinovosyldiacylglycerols derived from 2-O-beta-d-glucopyranosyl-sn-glycerol, carrying acyl chains of various length on the glycerol moiety, were prepared through a convenient synthetic procedure in which a sulfonate is introduced at the C-6 position of glucose by oxidation of a thioacetate in the presence of the unprotected secondary hydroxyl groups, and tested for their anti-tumor-promoting activity using a short-term in vitro assay for Epstein-Barr virus early antigen (EBV-EA) activation. Our study has allowed to ascertain the role of the 6'-sulfonate group and the need of a free hydroxyl group on the glycerol moiety in inhibiting the EBV activation promoted by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA).