Abstract
The naphthoquinone droserone (1) is a natural product occurring in dicotyledonous plants. We have now observed that
the addition of 1 during infection of tissue culture cells with measles virus considerably reduced
the infection. Interestingly, the infection was inhibited only when droserone (1) was added during virus entry, but not when added to the cells prior to virus uptake
or after virus uptake. These findings suggest that 1 interacts with viral particles to reduce infectivity. The formation of progeny measles
virus particles was inhibited to 50 % by droserone (1) at a concentration (IC50) of approximately 2 µM with a half-maximal cytotoxicity (CC50) of about 60 µM for Vero cells. Other tested naphthoquinone derivatives, among them
the likewise natural plumbagin (2), but also synthetic analogs, were either more cytotoxic or not as effective as 1. Thus, our data do not support the development of naphthoquinone derivatives into
antiviral compounds, but suggest that they may be interesting research tools to study
measles virus entry into cells.
Key words
Dioncophyllaceae - Ancistrocladaceae -
Triphyophyllum peltatum
- droserone - naphthoquinones - measles virus inhibition
