Anti-viral evaluation of sesquiterpene coumarins from Ferula assa-foetida against HSV-1

Several complications attributed with Herpes virus related infections and the emergence of drug resistant viruses prompt scientists to search for new drugs. Several terpenoids and coumarins have shown anti HSV effects while no sesquiterpene coumarin have been previously tested for HSV treatment. Three sesquiterpene coumarins [badrakemin acetate (1), kellerin (2) and samarcandin diasteromer (3) were isolated from the gum resin of Ferula assa-foetida, a herbal medicine with antimicrobial, antiprotozoal and antiviral effects. Compounds were identified by 1D and 2D- NMR spectroscopy and comparison with literature data. A comparative evaluation of cytotoxicity and anti-viral activity showed that kellerin (2) could significantly inhibit the cytopathic effects and reduce the viral titre of the herpes virus type 1 (HSV-1) DNA viral strains KOS at concentrations of 10, 5 and 2.5 µg/mL.