Assertion: black walnut's juglone | /r/HasProperty | characterized for first time
Facets:
value: by a. bernthsen
type: OTHER
value: by a. semper
type: OTHER
value: in 1887
type: TEMPORAL
Source sentences:
text: Juglone was then synthesized and characterized for the first time in 1887 by A. Bernthsen and A. Semper.