Task: Class Definition Understanding (ontology: Sciences/Biology)

Which of the following definitions best describes '5-oxobrucine'?

A. A monoterpenoid indole alkaloid with formula C23H24N2O5, originallly isolated from the seeds of Strychnos nux-vomica.
B. A 17beta-hydroxy steroid that is 17beta-estradiol in the the hydrogen at the 11beta position has been replaced by a p-({5-[(4,4,5,5,5-pentafluoropentyl)sulfonyl]pentyl}oxy)phenyl group. the concept is a pure anti-estrogen that downregulates estrogen receptor expression (IC50 = 0.04 nM).
C. A flavonolignan isolated from milk thistle, Silybum marianum, and has been shown to exhibit hepatoprotective activity.
D. A dicarboximide that is thalidomide substituted at position 5 by an ethenyl group, which in turn is substituted by two feruloyl groups at position 2. The compound is a hybrid based on the structures of thalidomide and curcumin and has been found to exhibit cytotoxicity against human multiple myeloma cells.

Answer: A monoterpenoid indole alkaloid with formula C23H24N2O5, originallly isolated from the seeds of Strychnos nux-vomica.