Figure 1.

Gramine and its synthetic derivatives inhibited virus-induced CPE. (A) Vero cells were infected with 100 TCID₅₀ of EV71 mixed with serial dilutions of tested compounds for 1.5 h at 37 °C; the inoculum was aspirated and cells were incubated with DMEM/tested compounds at 37 °C, 5% CO₂ for 48 h pi. The viability of the cells was determined with an MTT assay; (B) Morphology image of Vero and RD cells treated with compounds 4a, 4i, 4r, and 4s for 48 h pi. (magnification, 20×).