Inhibitory activity of cyclohexenyl chalcone derivatives and flavonoids of fingerroot, boesenbergia rotunda (L.), towards Dengue-2 virus NS3 protease

Boesenbergia rotunda (L.) cyclohexenyl chalcone derivatives, 4-hydroxypanduratin A and panduratin A, showed good competitive inhibitory activities towards dengue 2 virus NS3 protease with the K i values of 21 and 25 μM, respectively, whilst those of pinostrobin and cardamonin were observed to be non-competitive. NMR and GCMS spectroscopic data formed the basis of assignment of structures of the six compounds isolated