apamin

noun

ap·​a·​min ˈa-pə-mən 

: a neurotoxic polypeptide C₇₉H₁₃₁N₃₁O₂₄S₄ in the venom of the honeybee (Apis mellifera) that is used especially in biomedical research

Apamin is a potent bee venom toxin that blocks small calcium-activated potassium channels. This toxin is also the bee venom constituent responsible for the painful sensation that accompanies bee stings.

—David Gurwitz, The Lancet