Isolation of compounds from R. officinalis. (A) Anti-hRSV effect of the EtOAc fraction of R. officinalis EtOH extract. Anti-hRSV activities of EtOAc-soluble, hexane-soluble, BuOH-soluble, and total EtOH extracts were assessed by microneutralization assay as described in Figure 1. Data represent means ± SD. (B) Chemical structures of compounds isolated from the EtOAc fraction, which showed the strongest anti-hRSV activity.