drug isolation 226 article 176 nonhuman 176 unclassified drug 168 drug structure 102 controlled study 86 Animals 56 proton nuclear magnetic resonance 52 priority journal 50 carbon nuclear magnetic resonance 46 plant extract 46 Molecular Structure 40 antiviral activity 38 nuclear magnetic resonance 38 human 36 structure analysis 36 Humans 30 Magnetic Resonance Spectroscopy 30 cytotoxicity 30 human cell 30 Argentina 28 mass spectrometry 28 animal cell 26 in vitro study 26 phytochemistry 26 antifungal activity 24 drug cytotoxicity 24 Antiviral Agents 22 antivirus agent 22 drug identification 22