ANTIVIRAL ACTIVITIES OF ANTHRAQUINONES, BIANTHRONES AND HYPERICIN DERIVATIVES FROM LICHENS

The antiviral activities of some naturally occurring anthraquinones, b ianthrones, and hypericin derivatives were compared by the end-point C PE (viral cytopathic effects) method and plaque assays. Under optimal conditions of exposure to light, hypericin, 7,7'-dichlorohypericin and 5,7-dichloroemodin exhibited strong inhibitory activity against HSV-1 (herpes simplex virus type 1) in both assays. Partial inactivation of the virus was shown by emodin, 7-chloroemodin and 7-chloro-1-O-methyl emodin; the bianthrones and other anthraquinones were found to be inac tive. Antiviral activity appeared to be positively correlated with inc reasing substitution of chlorine in the anthraquinone structure. In th e absence of light, only hypericin and 7,7'-dichlorohypericin displaye d detectable activity.