Fig. 3.

Antiviral activity of SPR in epithelial cells. (A) EBV lytic replication was induced with TPA (+ ind.) in an GFP-EBV–infected gastric carcinoma cell line (AGS), which was then treated with SPR or EPR at various concentrations as shown. Virion production was measured by passage to 293 cells and quantitated by flow cytometry. EBV titer expressed as the number of GFP-transducing units per mL is shown on the y axis. (B) Antiviral activities of CAN, TMS, and EPR (E) were compared with SPR as in A. Cells were either untreated (–) or treated (+) to induce lytic replication (ind). (C) Structures of SPR, CAN, TMS, and EPR are shown. The thioacetyl group at C-7 of SPR is circled.