In pursuing a research on the antiviral and immunomodulatory activity of tilorone congeners, two new series of compounds were prepared and pharmacologically explored: 9-fluorenone carboxyhydroxyesters, indicated as AG, and 9-fluorenone carboxyhydroxamides, indicated as MG. Two of them, AG17 and MG3, were used as sugar acceptors in the transglycosylation reactions performed by alpha- and beta-glucosidases extracted from the marine mollusc Aplysia fasciata providing different alpha- and beta-, mono- and oligosaccharides. Then aglycons and saccharides were assayed for cytotoxicity, for anti-herpes virus-2 properties on peripheral blood mononuclear cells (PBMC) and for their capability to trigger human cells to produce antiviral cytokines such as IFNalpha and TNFalpha. Some promising compounds were individuated whereas the utility of the biocatalytic procedures in the preparation of pure anomeric material was further focused.