Anti-HSV activity of camptothecin analogues

Abstract

In order to explore the range of biological activities of the camptothecin compound class, the in vitro antiviral efficacies of series I–IV of representative members from camptothecin analogues on herpes simplex virus type 2 (HSV-2) were evaluated on vero cells. Several compounds exhibited similar or better antiviral activity against HSV-2 in vitro than acyclovir. Among them, compound 6 showed the highest anti-HSV-2 activity, with IC₅₀ values of 1.3 µg mL⁻¹ and SI values of 27.04, respectively. On the basis of preliminary biological testing results, it is suggested that the intact E lactone ring and 20-hydroxy group should be not a prerequisite for camptothecin-like antiviral activity, and CPT substitution at the C-20 hydroxy group may be optimal for synthesising more potent antiviral compounds, suggesting that CPT has the potential to be a lead structure for semi-synthetic antiviral agents.