unclassified drug article 98 nonhuman 86 controlled study 72 Animals 56 priority journal 56 animal experiment 26 animal tissue 26 animal cell 24 enzyme activity 22 Article 20 drug structure 20 metabolism 20 Humans 18 animal 18 enzyme inhibition 18 human 18 male 18 Esters 16 Male 16 Molecular Structure 16 chemistry 16 concentration response 16 drug isolation 16 ester derivative 16 Cercopithecus aethiops 14 Cholinesterases 14 Gastropoda 14 Magnetic Resonance Spectroscopy 14 chemical structure 14