ADORA2A and Anxiety: Compounds such as acetylshikonin and 2-methyl-n-butyrylshikonin regulate neuroactive ligand-receptor interaction pathways through targets such as recombinant adenosine a1 receptor (ADORA1) and adenosine a2a receptor (ADORA2A), allowing exertion of anti-anxiety effects (Fig. 5A,B).