Gramine (Donaxine), a natural indole alkaloid, present in several plant species, acts as an active adiponectin receptor (AdipoR) agonist, with IC50s of 3.2 and 4.2 μM for AdipoR2 and AdipoR1, respectively. Gramine is also a human and mouse β2-Adrenergic receptor (β2-AR) agonist. Gramine has anti-tumor, anti-viral and anti-inflammatory properties.