Isolation of the anthropogenic compound fluoranthene in a screening of Chinese medicinal plants for antiviral compounds.

Thirty-one species of medicinal plants used in the treatment of diseases of viral origin in Yunnan Province of China were assayed for inhibition of Sindbis and murine cytomegalovirus in mammalian cell cultures. Sixteen species displayed antiviral activity. A compound, which exhibited long wavelength UV-mediated antiviral activity, was isolated from leaves and twigs of Elsholtzia ciliata (Lamiaceae) using bioassay-guided fractionation and identified as the polycyclic aromatic hydrocarbon, fluoranthene. The discovery of an anthropogenic photosensitizer with antiviral activity in a plant has implications in studies of plants as sources of bioactive constituents.