Fig. 1From: Antiviral activity of phenanthrenes from the medicinal plant Bletilla striata against influenza A virusHPLC and LC–MS analyses of the compounds isolated from Bletilla striata. a HPLC fingerprint chromatogram of the 12 phenanthrenes isolated from Bletilla striata. b Total ion current chromatogram of the 12 phenanthrenes isolated from Bletilla striata, in the negative ion mode LC-MS. c Total ion current of chromatogram of the 12 phenanthrenes isolated from Bletilla striata, in the positive ion LC-MSBack to article page