Investigation of the Adrenergic and Opioid Binding Affinities, Metabolic Stability, Plasma Protein Binding Properties, and Functional Effects of Selected Indole-Based Kratom Alkaloids

Selected indole-based kratom alkaloids were evaluated
for their
opioid and adrenergic receptor binding and functional effects, in
vivo antinociceptive effects, plasma protein binding, and metabolic
stability. Mitragynine, the major alkaloid in Mitragyna
speciosa (kratom), had higher affinity at opioid receptors
than at adrenergic receptors while the vice versa was observed for
corynantheidine. The observed polypharmacology of kratom alkaloids
may support its utilization to treat opioid use disorder and withdrawal.