18,20 epoxy 18 methoxy 1,4 dioxowitha 2,5,24 trienolide 2 18,20 epoxy 4beta,18 dihydroxy 1 oxowitha 2,5,24 trienolide 2 4beta hydroxy 18,20 epoxy 1,18 dioxowitha 2,5,24 trienolide 2 4beta hydroxy 18,20 epoxy 18 methoxy 1 oxowitha 2,5,24 trienolide 2 5beta,6beta epoxy 4beta,18,20 trihydroxy 1 oxowitha 2,24 dienolide 2 5beta,6beta:18,20 diepoxy 18 hydroxy 1 oxowitha 2,5,24 trienolide 2 Animals 2 Antimalarials 2 Ergosterol 2 Humans 2 Lactones 2 Magnetic Resonance Spectroscopy 2 Plasmodium falciparum 2 Solanaceae 2 Vassobia 2 Vassobia lorentzii extract 2 article 2 chemical structure 2 chemotaxonomy 2 extraction 2 isomer 2 molecular model 2 nonhuman 2 plant extract 2 spectroscopy 2 unclassified drug 2 withanolide 2