Allomatrine is a natural product from Sophora alopecuroides L. Allomatrine when given i.c.v. may stimulate the descending dynorphinergic neuron resulting in the stimulation of KORs in the spinal cord.

D-Asparagine is a source of nitrogen for yeast strains. D-Asparagine is a competitive inhibitor of L-Asparagine hydrolysis (Ki = 0.24 mM).

Vanillin is mainly used as a flavouring agent, primarily in foods and beverages such as chocolate and dairy products, but also to mask unpleasant tastes in medicines or livestock fodder.