Effect of alkaloids isolated from Amaryllidaceae on herpes simplex virus.

Studies were carried out on the effects of Amaryllidaceae alkaloids and their derivatives upon herpes simplex virus (type 1), the relationship between their structure and antiviral activity and the mechanism of this activity. All alkaloids used in these experiments were biosynthesized from N-benzylphenethylamine; the apogalanthamine group was synthesized in our laboratory; those which may eventually prove to be antiviral agents had a hexahydroindole ring with two functional hydroxyl groups. Benzazepine compounds were neither cytotoxic nor antiviral, but many structures containing dibenzazocine were toxic at low concentrations. It was established that the antiviral activity of alkaloids is due to the inhibition of multiplication and not to the direct inactivation of extracellular viruses. The mechanism of the antiviral effect could be partly explained as a blocking of viral DNA polymerase activity.